1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24 /*
  25  * Copyright (c) 2010, Intel Corporation.
  26  * All rights reserved.
  27  */
  28 /*
  29  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  30  * Copyright 2017 Joyent, Inc.  All rights reserved.
  31  * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
  32  */
  33 
  34 /*
  35  * VM - Hardware Address Translation management for i386 and amd64
  36  *
  37  * Implementation of the interfaces described in <common/vm/hat.h>
  38  *
  39  * Nearly all the details of how the hardware is managed should not be
  40  * visible outside this layer except for misc. machine specific functions
  41  * that work in conjunction with this code.
  42  *
  43  * Routines used only inside of i86pc/vm start with hati_ for HAT Internal.
  44  */
  45 
  46 #include <sys/machparam.h>
  47 #include <sys/machsystm.h>
  48 #include <sys/mman.h>
  49 #include <sys/types.h>
  50 #include <sys/systm.h>
  51 #include <sys/cpuvar.h>
  52 #include <sys/thread.h>
  53 #include <sys/proc.h>
  54 #include <sys/cpu.h>
  55 #include <sys/kmem.h>
  56 #include <sys/disp.h>
  57 #include <sys/shm.h>
  58 #include <sys/sysmacros.h>
  59 #include <sys/machparam.h>
  60 #include <sys/vmem.h>
  61 #include <sys/vmsystm.h>
  62 #include <sys/promif.h>
  63 #include <sys/var.h>
  64 #include <sys/x86_archext.h>
  65 #include <sys/atomic.h>
  66 #include <sys/bitmap.h>
  67 #include <sys/controlregs.h>
  68 #include <sys/bootconf.h>
  69 #include <sys/bootsvcs.h>
  70 #include <sys/bootinfo.h>
  71 #include <sys/archsystm.h>
  72 
  73 #include <vm/seg_kmem.h>
  74 #include <vm/hat_i86.h>
  75 #include <vm/as.h>
  76 #include <vm/seg.h>
  77 #include <vm/page.h>
  78 #include <vm/seg_kp.h>
  79 #include <vm/seg_kpm.h>
  80 #include <vm/vm_dep.h>
  81 #ifdef __xpv
  82 #include <sys/hypervisor.h>
  83 #endif
  84 #include <vm/kboot_mmu.h>
  85 #include <vm/seg_spt.h>
  86 
  87 #include <sys/cmn_err.h>
  88 
  89 /*
  90  * Basic parameters for hat operation.
  91  */
  92 struct hat_mmu_info mmu;
  93 
  94 /*
  95  * The page that is the kernel's top level pagetable.
  96  *
  97  * For 32 bit PAE support on i86pc, the kernel hat will use the 1st 4 entries
  98  * on this 4K page for its top level page table. The remaining groups of
  99  * 4 entries are used for per processor copies of user VLP pagetables for
 100  * running threads.  See hat_switch() and reload_pae32() for details.
 101  *
 102  * vlp_page[0..3] - level==2 PTEs for kernel HAT
 103  * vlp_page[4..7] - level==2 PTEs for user thread on cpu 0
 104  * vlp_page[8..11]  - level==2 PTE for user thread on cpu 1
 105  * etc...
 106  */
 107 static x86pte_t *vlp_page;
 108 
 109 /*
 110  * forward declaration of internal utility routines
 111  */
 112 static x86pte_t hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected,
 113         x86pte_t new);
 114 
 115 /*
 116  * The kernel address space exists in all HATs. To implement this the
 117  * kernel reserves a fixed number of entries in the topmost level(s) of page
 118  * tables. The values are setup during startup and then copied to every user
 119  * hat created by hat_alloc(). This means that kernelbase must be:
 120  *
 121  *        4Meg aligned for 32 bit kernels
 122  *      512Gig aligned for x86_64 64 bit kernel
 123  *
 124  * The hat_kernel_range_ts describe what needs to be copied from kernel hat
 125  * to each user hat.
 126  */
 127 typedef struct hat_kernel_range {
 128         level_t         hkr_level;
 129         uintptr_t       hkr_start_va;
 130         uintptr_t       hkr_end_va;     /* zero means to end of memory */
 131 } hat_kernel_range_t;
 132 #define NUM_KERNEL_RANGE 2
 133 static hat_kernel_range_t kernel_ranges[NUM_KERNEL_RANGE];
 134 static int num_kernel_ranges;
 135 
 136 uint_t use_boot_reserve = 1;    /* cleared after early boot process */
 137 uint_t can_steal_post_boot = 0; /* set late in boot to enable stealing */
 138 
 139 /*
 140  * enable_1gpg: controls 1g page support for user applications.
 141  * By default, 1g pages are exported to user applications. enable_1gpg can
 142  * be set to 0 to not export.
 143  */
 144 int     enable_1gpg = 1;
 145 
 146 /*
 147  * AMD shanghai processors provide better management of 1gb ptes in its tlb.
 148  * By default, 1g page support will be disabled for pre-shanghai AMD
 149  * processors that don't have optimal tlb support for the 1g page size.
 150  * chk_optimal_1gtlb can be set to 0 to force 1g page support on sub-optimal
 151  * processors.
 152  */
 153 int     chk_optimal_1gtlb = 1;
 154 
 155 
 156 #ifdef DEBUG
 157 uint_t  map1gcnt;
 158 #endif
 159 
 160 
 161 /*
 162  * A cpuset for all cpus. This is used for kernel address cross calls, since
 163  * the kernel addresses apply to all cpus.
 164  */
 165 cpuset_t khat_cpuset;
 166 
 167 /*
 168  * management stuff for hat structures
 169  */
 170 kmutex_t        hat_list_lock;
 171 kcondvar_t      hat_list_cv;
 172 kmem_cache_t    *hat_cache;
 173 kmem_cache_t    *hat_hash_cache;
 174 kmem_cache_t    *vlp_hash_cache;
 175 
 176 /*
 177  * Simple statistics
 178  */
 179 struct hatstats hatstat;
 180 
 181 /*
 182  * Some earlier hypervisor versions do not emulate cmpxchg of PTEs
 183  * correctly.  For such hypervisors we must set PT_USER for kernel
 184  * entries ourselves (normally the emulation would set PT_USER for
 185  * kernel entries and PT_USER|PT_GLOBAL for user entries).  pt_kern is
 186  * thus set appropriately.  Note that dboot/kbm is OK, as only the full
 187  * HAT uses cmpxchg() and the other paths (hypercall etc.) were never
 188  * incorrect.
 189  */
 190 int pt_kern;
 191 
 192 /*
 193  * useful stuff for atomic access/clearing/setting REF/MOD/RO bits in page_t's.
 194  */
 195 extern void atomic_orb(uchar_t *addr, uchar_t val);
 196 extern void atomic_andb(uchar_t *addr, uchar_t val);
 197 
 198 #ifndef __xpv
 199 extern pfn_t memseg_get_start(struct memseg *);
 200 #endif
 201 
 202 #define PP_GETRM(pp, rmmask)    (pp->p_nrm & rmmask)
 203 #define PP_ISMOD(pp)            PP_GETRM(pp, P_MOD)
 204 #define PP_ISREF(pp)            PP_GETRM(pp, P_REF)
 205 #define PP_ISRO(pp)             PP_GETRM(pp, P_RO)
 206 
 207 #define PP_SETRM(pp, rm)        atomic_orb(&(pp->p_nrm), rm)
 208 #define PP_SETMOD(pp)           PP_SETRM(pp, P_MOD)
 209 #define PP_SETREF(pp)           PP_SETRM(pp, P_REF)
 210 #define PP_SETRO(pp)            PP_SETRM(pp, P_RO)
 211 
 212 #define PP_CLRRM(pp, rm)        atomic_andb(&(pp->p_nrm), ~(rm))
 213 #define PP_CLRMOD(pp)           PP_CLRRM(pp, P_MOD)
 214 #define PP_CLRREF(pp)           PP_CLRRM(pp, P_REF)
 215 #define PP_CLRRO(pp)            PP_CLRRM(pp, P_RO)
 216 #define PP_CLRALL(pp)           PP_CLRRM(pp, P_MOD | P_REF | P_RO)
 217 
 218 /*
 219  * kmem cache constructor for struct hat
 220  */
 221 /*ARGSUSED*/
 222 static int
 223 hati_constructor(void *buf, void *handle, int kmflags)
 224 {
 225         hat_t   *hat = buf;
 226 
 227         mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 228         bzero(hat->hat_pages_mapped,
 229             sizeof (pgcnt_t) * (mmu.max_page_level + 1));
 230         hat->hat_ism_pgcnt = 0;
 231         hat->hat_stats = 0;
 232         hat->hat_flags = 0;
 233         CPUSET_ZERO(hat->hat_cpus);
 234         hat->hat_htable = NULL;
 235         hat->hat_ht_hash = NULL;
 236         return (0);
 237 }
 238 
 239 /*
 240  * Allocate a hat structure for as. We also create the top level
 241  * htable and initialize it to contain the kernel hat entries.
 242  */
 243 hat_t *
 244 hat_alloc(struct as *as)
 245 {
 246         hat_t                   *hat;
 247         htable_t                *ht;    /* top level htable */
 248         uint_t                  use_vlp;
 249         uint_t                  r;
 250         hat_kernel_range_t      *rp;
 251         uintptr_t               va;
 252         uintptr_t               eva;
 253         uint_t                  start;
 254         uint_t                  cnt;
 255         htable_t                *src;
 256 
 257         /*
 258          * Once we start creating user process HATs we can enable
 259          * the htable_steal() code.
 260          */
 261         if (can_steal_post_boot == 0)
 262                 can_steal_post_boot = 1;
 263 
 264         ASSERT(AS_WRITE_HELD(as));
 265         hat = kmem_cache_alloc(hat_cache, KM_SLEEP);
 266         hat->hat_as = as;
 267         mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 268         ASSERT(hat->hat_flags == 0);
 269 
 270 #if defined(__xpv)
 271         /*
 272          * No VLP stuff on the hypervisor due to the 64-bit split top level
 273          * page tables.  On 32-bit it's not needed as the hypervisor takes
 274          * care of copying the top level PTEs to a below 4Gig page.
 275          */
 276         use_vlp = 0;
 277 #else   /* __xpv */
 278         /* 32 bit processes uses a VLP style hat when running with PAE */
 279 #if defined(__amd64)
 280         use_vlp = (ttoproc(curthread)->p_model == DATAMODEL_ILP32);
 281 #elif defined(__i386)
 282         use_vlp = mmu.pae_hat;
 283 #endif
 284 #endif  /* __xpv */
 285         if (use_vlp) {
 286                 hat->hat_flags = HAT_VLP;
 287                 bzero(hat->hat_vlp_ptes, VLP_SIZE);
 288         }
 289 
 290         /*
 291          * Allocate the htable hash
 292          */
 293         if ((hat->hat_flags & HAT_VLP)) {
 294                 hat->hat_num_hash = mmu.vlp_hash_cnt;
 295                 hat->hat_ht_hash = kmem_cache_alloc(vlp_hash_cache, KM_SLEEP);
 296         } else {
 297                 hat->hat_num_hash = mmu.hash_cnt;
 298                 hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_SLEEP);
 299         }
 300         bzero(hat->hat_ht_hash, hat->hat_num_hash * sizeof (htable_t *));
 301 
 302         /*
 303          * Initialize Kernel HAT entries at the top of the top level page
 304          * tables for the new hat.
 305          */
 306         hat->hat_htable = NULL;
 307         hat->hat_ht_cached = NULL;
 308         XPV_DISALLOW_MIGRATE();
 309         ht = htable_create(hat, (uintptr_t)0, TOP_LEVEL(hat), NULL);
 310         hat->hat_htable = ht;
 311 
 312 #if defined(__amd64)
 313         if (hat->hat_flags & HAT_VLP)
 314                 goto init_done;
 315 #endif
 316 
 317         for (r = 0; r < num_kernel_ranges; ++r) {
 318                 rp = &kernel_ranges[r];
 319                 for (va = rp->hkr_start_va; va != rp->hkr_end_va;
 320                     va += cnt * LEVEL_SIZE(rp->hkr_level)) {
 321 
 322                         if (rp->hkr_level == TOP_LEVEL(hat))
 323                                 ht = hat->hat_htable;
 324                         else
 325                                 ht = htable_create(hat, va, rp->hkr_level,
 326                                     NULL);
 327 
 328                         start = htable_va2entry(va, ht);
 329                         cnt = HTABLE_NUM_PTES(ht) - start;
 330                         eva = va +
 331                             ((uintptr_t)cnt << LEVEL_SHIFT(rp->hkr_level));
 332                         if (rp->hkr_end_va != 0 &&
 333                             (eva > rp->hkr_end_va || eva == 0))
 334                                 cnt = htable_va2entry(rp->hkr_end_va, ht) -
 335                                     start;
 336 
 337 #if defined(__i386) && !defined(__xpv)
 338                         if (ht->ht_flags & HTABLE_VLP) {
 339                                 bcopy(&vlp_page[start],
 340                                     &hat->hat_vlp_ptes[start],
 341                                     cnt * sizeof (x86pte_t));
 342                                 continue;
 343                         }
 344 #endif
 345                         src = htable_lookup(kas.a_hat, va, rp->hkr_level);
 346                         ASSERT(src != NULL);
 347                         x86pte_copy(src, ht, start, cnt);
 348                         htable_release(src);
 349                 }
 350         }
 351 
 352 init_done:
 353 
 354 #if defined(__xpv)
 355         /*
 356          * Pin top level page tables after initializing them
 357          */
 358         xen_pin(hat->hat_htable->ht_pfn, mmu.max_level);
 359 #if defined(__amd64)
 360         xen_pin(hat->hat_user_ptable, mmu.max_level);
 361 #endif
 362 #endif
 363         XPV_ALLOW_MIGRATE();
 364 
 365         /*
 366          * Put it at the start of the global list of all hats (used by stealing)
 367          *
 368          * kas.a_hat is not in the list but is instead used to find the
 369          * first and last items in the list.
 370          *
 371          * - kas.a_hat->hat_next points to the start of the user hats.
 372          *   The list ends where hat->hat_next == NULL
 373          *
 374          * - kas.a_hat->hat_prev points to the last of the user hats.
 375          *   The list begins where hat->hat_prev == NULL
 376          */
 377         mutex_enter(&hat_list_lock);
 378         hat->hat_prev = NULL;
 379         hat->hat_next = kas.a_hat->hat_next;
 380         if (hat->hat_next)
 381                 hat->hat_next->hat_prev = hat;
 382         else
 383                 kas.a_hat->hat_prev = hat;
 384         kas.a_hat->hat_next = hat;
 385         mutex_exit(&hat_list_lock);
 386 
 387         return (hat);
 388 }
 389 
 390 /*
 391  * process has finished executing but as has not been cleaned up yet.
 392  */
 393 /*ARGSUSED*/
 394 void
 395 hat_free_start(hat_t *hat)
 396 {
 397         ASSERT(AS_WRITE_HELD(hat->hat_as));
 398 
 399         /*
 400          * If the hat is currently a stealing victim, wait for the stealing
 401          * to finish.  Once we mark it as HAT_FREEING, htable_steal()
 402          * won't look at its pagetables anymore.
 403          */
 404         mutex_enter(&hat_list_lock);
 405         while (hat->hat_flags & HAT_VICTIM)
 406                 cv_wait(&hat_list_cv, &hat_list_lock);
 407         hat->hat_flags |= HAT_FREEING;
 408         mutex_exit(&hat_list_lock);
 409 }
 410 
 411 /*
 412  * An address space is being destroyed, so we destroy the associated hat.
 413  */
 414 void
 415 hat_free_end(hat_t *hat)
 416 {
 417         kmem_cache_t *cache;
 418 
 419         ASSERT(hat->hat_flags & HAT_FREEING);
 420 
 421         /*
 422          * must not be running on the given hat
 423          */
 424         ASSERT(CPU->cpu_current_hat != hat);
 425 
 426         /*
 427          * Remove it from the list of HATs
 428          */
 429         mutex_enter(&hat_list_lock);
 430         if (hat->hat_prev)
 431                 hat->hat_prev->hat_next = hat->hat_next;
 432         else
 433                 kas.a_hat->hat_next = hat->hat_next;
 434         if (hat->hat_next)
 435                 hat->hat_next->hat_prev = hat->hat_prev;
 436         else
 437                 kas.a_hat->hat_prev = hat->hat_prev;
 438         mutex_exit(&hat_list_lock);
 439         hat->hat_next = hat->hat_prev = NULL;
 440 
 441 #if defined(__xpv)
 442         /*
 443          * On the hypervisor, unpin top level page table(s)
 444          */
 445         xen_unpin(hat->hat_htable->ht_pfn);
 446 #if defined(__amd64)
 447         xen_unpin(hat->hat_user_ptable);
 448 #endif
 449 #endif
 450 
 451         /*
 452          * Make a pass through the htables freeing them all up.
 453          */
 454         htable_purge_hat(hat);
 455 
 456         /*
 457          * Decide which kmem cache the hash table came from, then free it.
 458          */
 459         if (hat->hat_flags & HAT_VLP)
 460                 cache = vlp_hash_cache;
 461         else
 462                 cache = hat_hash_cache;
 463         kmem_cache_free(cache, hat->hat_ht_hash);
 464         hat->hat_ht_hash = NULL;
 465 
 466         hat->hat_flags = 0;
 467         kmem_cache_free(hat_cache, hat);
 468 }
 469 
 470 /*
 471  * round kernelbase down to a supported value to use for _userlimit
 472  *
 473  * userlimit must be aligned down to an entry in the top level htable.
 474  * The one exception is for 32 bit HAT's running PAE.
 475  */
 476 uintptr_t
 477 hat_kernelbase(uintptr_t va)
 478 {
 479 #if defined(__i386)
 480         va &= LEVEL_MASK(1);
 481 #endif
 482         if (IN_VA_HOLE(va))
 483                 panic("_userlimit %p will fall in VA hole\n", (void *)va);
 484         return (va);
 485 }
 486 
 487 /*
 488  *
 489  */
 490 static void
 491 set_max_page_level()
 492 {
 493         level_t lvl;
 494 
 495         if (!kbm_largepage_support) {
 496                 lvl = 0;
 497         } else {
 498                 if (is_x86_feature(x86_featureset, X86FSET_1GPG)) {
 499                         lvl = 2;
 500                         if (chk_optimal_1gtlb &&
 501                             cpuid_opteron_erratum(CPU, 6671130)) {
 502                                 lvl = 1;
 503                         }
 504                         if (plat_mnode_xcheck(LEVEL_SIZE(2) >>
 505                             LEVEL_SHIFT(0))) {
 506                                 lvl = 1;
 507                         }
 508                 } else {
 509                         lvl = 1;
 510                 }
 511         }
 512         mmu.max_page_level = lvl;
 513 
 514         if ((lvl == 2) && (enable_1gpg == 0))
 515                 mmu.umax_page_level = 1;
 516         else
 517                 mmu.umax_page_level = lvl;
 518 }
 519 
 520 /*
 521  * Initialize hat data structures based on processor MMU information.
 522  */
 523 void
 524 mmu_init(void)
 525 {
 526         uint_t max_htables;
 527         uint_t pa_bits;
 528         uint_t va_bits;
 529         int i;
 530 
 531         /*
 532          * If CPU enabled the page table global bit, use it for the kernel
 533          * This is bit 7 in CR4 (PGE - Page Global Enable).
 534          */
 535         if (is_x86_feature(x86_featureset, X86FSET_PGE) &&
 536             (getcr4() & CR4_PGE) != 0)
 537                 mmu.pt_global = PT_GLOBAL;
 538 
 539         /*
 540          * Detect NX and PAE usage.
 541          */
 542         mmu.pae_hat = kbm_pae_support;
 543         if (kbm_nx_support)
 544                 mmu.pt_nx = PT_NX;
 545         else
 546                 mmu.pt_nx = 0;
 547 
 548         /*
 549          * Use CPU info to set various MMU parameters
 550          */
 551         cpuid_get_addrsize(CPU, &pa_bits, &va_bits);
 552 
 553         if (va_bits < sizeof (void *) * NBBY) {
 554                 mmu.hole_start = (1ul << (va_bits - 1));
 555                 mmu.hole_end = 0ul - mmu.hole_start - 1;
 556         } else {
 557                 mmu.hole_end = 0;
 558                 mmu.hole_start = mmu.hole_end - 1;
 559         }
 560 #if defined(OPTERON_ERRATUM_121)
 561         /*
 562          * If erratum 121 has already been detected at this time, hole_start
 563          * contains the value to be subtracted from mmu.hole_start.
 564          */
 565         ASSERT(hole_start == 0 || opteron_erratum_121 != 0);
 566         hole_start = mmu.hole_start - hole_start;
 567 #else
 568         hole_start = mmu.hole_start;
 569 #endif
 570         hole_end = mmu.hole_end;
 571 
 572         mmu.highest_pfn = mmu_btop((1ull << pa_bits) - 1);
 573         if (mmu.pae_hat == 0 && pa_bits > 32)
 574                 mmu.highest_pfn = PFN_4G - 1;
 575 
 576         if (mmu.pae_hat) {
 577                 mmu.pte_size = 8;       /* 8 byte PTEs */
 578                 mmu.pte_size_shift = 3;
 579         } else {
 580                 mmu.pte_size = 4;       /* 4 byte PTEs */
 581                 mmu.pte_size_shift = 2;
 582         }
 583 
 584         if (mmu.pae_hat && !is_x86_feature(x86_featureset, X86FSET_PAE))
 585                 panic("Processor does not support PAE");
 586 
 587         if (!is_x86_feature(x86_featureset, X86FSET_CX8))
 588                 panic("Processor does not support cmpxchg8b instruction");
 589 
 590 #if defined(__amd64)
 591 
 592         mmu.num_level = 4;
 593         mmu.max_level = 3;
 594         mmu.ptes_per_table = 512;
 595         mmu.top_level_count = 512;
 596 
 597         mmu.level_shift[0] = 12;
 598         mmu.level_shift[1] = 21;
 599         mmu.level_shift[2] = 30;
 600         mmu.level_shift[3] = 39;
 601 
 602 #elif defined(__i386)
 603 
 604         if (mmu.pae_hat) {
 605                 mmu.num_level = 3;
 606                 mmu.max_level = 2;
 607                 mmu.ptes_per_table = 512;
 608                 mmu.top_level_count = 4;
 609 
 610                 mmu.level_shift[0] = 12;
 611                 mmu.level_shift[1] = 21;
 612                 mmu.level_shift[2] = 30;
 613 
 614         } else {
 615                 mmu.num_level = 2;
 616                 mmu.max_level = 1;
 617                 mmu.ptes_per_table = 1024;
 618                 mmu.top_level_count = 1024;
 619 
 620                 mmu.level_shift[0] = 12;
 621                 mmu.level_shift[1] = 22;
 622         }
 623 
 624 #endif  /* __i386 */
 625 
 626         for (i = 0; i < mmu.num_level; ++i) {
 627                 mmu.level_size[i] = 1UL << mmu.level_shift[i];
 628                 mmu.level_offset[i] = mmu.level_size[i] - 1;
 629                 mmu.level_mask[i] = ~mmu.level_offset[i];
 630         }
 631 
 632         set_max_page_level();
 633 
 634         mmu_page_sizes = mmu.max_page_level + 1;
 635         mmu_exported_page_sizes = mmu.umax_page_level + 1;
 636 
 637         /* restrict legacy applications from using pagesizes 1g and above */
 638         mmu_legacy_page_sizes =
 639             (mmu_exported_page_sizes > 2) ? 2 : mmu_exported_page_sizes;
 640 
 641 
 642         for (i = 0; i <= mmu.max_page_level; ++i) {
 643                 mmu.pte_bits[i] = PT_VALID | pt_kern;
 644                 if (i > 0)
 645                         mmu.pte_bits[i] |= PT_PAGESIZE;
 646         }
 647 
 648         /*
 649          * NOTE Legacy 32 bit PAE mode only has the P_VALID bit at top level.
 650          */
 651         for (i = 1; i < mmu.num_level; ++i)
 652                 mmu.ptp_bits[i] = PT_PTPBITS;
 653 
 654 #if defined(__i386)
 655         mmu.ptp_bits[2] = PT_VALID;
 656 #endif
 657 
 658         /*
 659          * Compute how many hash table entries to have per process for htables.
 660          * We start with 1 page's worth of entries.
 661          *
 662          * If physical memory is small, reduce the amount need to cover it.
 663          */
 664         max_htables = physmax / mmu.ptes_per_table;
 665         mmu.hash_cnt = MMU_PAGESIZE / sizeof (htable_t *);
 666         while (mmu.hash_cnt > 16 && mmu.hash_cnt >= max_htables)
 667                 mmu.hash_cnt >>= 1;
 668         mmu.vlp_hash_cnt = mmu.hash_cnt;
 669 
 670 #if defined(__amd64)
 671         /*
 672          * If running in 64 bits and physical memory is large,
 673          * increase the size of the cache to cover all of memory for
 674          * a 64 bit process.
 675          */
 676 #define HASH_MAX_LENGTH 4
 677         while (mmu.hash_cnt * HASH_MAX_LENGTH < max_htables)
 678                 mmu.hash_cnt <<= 1;
 679 #endif
 680 }
 681 
 682 
 683 /*
 684  * initialize hat data structures
 685  */
 686 void
 687 hat_init()
 688 {
 689 #if defined(__i386)
 690         /*
 691          * _userlimit must be aligned correctly
 692          */
 693         if ((_userlimit & LEVEL_MASK(1)) != _userlimit) {
 694                 prom_printf("hat_init(): _userlimit=%p, not aligned at %p\n",
 695                     (void *)_userlimit, (void *)LEVEL_SIZE(1));
 696                 halt("hat_init(): Unable to continue");
 697         }
 698 #endif
 699 
 700         cv_init(&hat_list_cv, NULL, CV_DEFAULT, NULL);
 701 
 702         /*
 703          * initialize kmem caches
 704          */
 705         htable_init();
 706         hment_init();
 707 
 708         hat_cache = kmem_cache_create("hat_t",
 709             sizeof (hat_t), 0, hati_constructor, NULL, NULL,
 710             NULL, 0, 0);
 711 
 712         hat_hash_cache = kmem_cache_create("HatHash",
 713             mmu.hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
 714             NULL, 0, 0);
 715 
 716         /*
 717          * VLP hats can use a smaller hash table size on large memroy machines
 718          */
 719         if (mmu.hash_cnt == mmu.vlp_hash_cnt) {
 720                 vlp_hash_cache = hat_hash_cache;
 721         } else {
 722                 vlp_hash_cache = kmem_cache_create("HatVlpHash",
 723                     mmu.vlp_hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
 724                     NULL, 0, 0);
 725         }
 726 
 727         /*
 728          * Set up the kernel's hat
 729          */
 730         AS_LOCK_ENTER(&kas, RW_WRITER);
 731         kas.a_hat = kmem_cache_alloc(hat_cache, KM_NOSLEEP);
 732         mutex_init(&kas.a_hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 733         kas.a_hat->hat_as = &kas;
 734         kas.a_hat->hat_flags = 0;
 735         AS_LOCK_EXIT(&kas);
 736 
 737         CPUSET_ZERO(khat_cpuset);
 738         CPUSET_ADD(khat_cpuset, CPU->cpu_id);
 739 
 740         /*
 741          * The kernel hat's next pointer serves as the head of the hat list .
 742          * The kernel hat's prev pointer tracks the last hat on the list for
 743          * htable_steal() to use.
 744          */
 745         kas.a_hat->hat_next = NULL;
 746         kas.a_hat->hat_prev = NULL;
 747 
 748         /*
 749          * Allocate an htable hash bucket for the kernel
 750          * XX64 - tune for 64 bit procs
 751          */
 752         kas.a_hat->hat_num_hash = mmu.hash_cnt;
 753         kas.a_hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_NOSLEEP);
 754         bzero(kas.a_hat->hat_ht_hash, mmu.hash_cnt * sizeof (htable_t *));
 755 
 756         /*
 757          * zero out the top level and cached htable pointers
 758          */
 759         kas.a_hat->hat_ht_cached = NULL;
 760         kas.a_hat->hat_htable = NULL;
 761 
 762         /*
 763          * Pre-allocate hrm_hashtab before enabling the collection of
 764          * refmod statistics.  Allocating on the fly would mean us
 765          * running the risk of suffering recursive mutex enters or
 766          * deadlocks.
 767          */
 768         hrm_hashtab = kmem_zalloc(HRM_HASHSIZE * sizeof (struct hrmstat *),
 769             KM_SLEEP);
 770 }
 771 
 772 /*
 773  * Prepare CPU specific pagetables for VLP processes on 64 bit kernels.
 774  *
 775  * Each CPU has a set of 2 pagetables that are reused for any 32 bit
 776  * process it runs. They are the top level pagetable, hci_vlp_l3ptes, and
 777  * the next to top level table for the bottom 512 Gig, hci_vlp_l2ptes.
 778  */
 779 /*ARGSUSED*/
 780 static void
 781 hat_vlp_setup(struct cpu *cpu)
 782 {
 783 #if defined(__amd64) && !defined(__xpv)
 784         struct hat_cpu_info *hci = cpu->cpu_hat_info;
 785         pfn_t pfn;
 786 
 787         /*
 788          * allocate the level==2 page table for the bottom most
 789          * 512Gig of address space (this is where 32 bit apps live)
 790          */
 791         ASSERT(hci != NULL);
 792         hci->hci_vlp_l2ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
 793 
 794         /*
 795          * Allocate a top level pagetable and copy the kernel's
 796          * entries into it. Then link in hci_vlp_l2ptes in the 1st entry.
 797          */
 798         hci->hci_vlp_l3ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
 799         hci->hci_vlp_pfn =
 800             hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l3ptes);
 801         ASSERT(hci->hci_vlp_pfn != PFN_INVALID);
 802         bcopy(vlp_page, hci->hci_vlp_l3ptes, MMU_PAGESIZE);
 803 
 804         pfn = hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l2ptes);
 805         ASSERT(pfn != PFN_INVALID);
 806         hci->hci_vlp_l3ptes[0] = MAKEPTP(pfn, 2);
 807 #endif /* __amd64 && !__xpv */
 808 }
 809 
 810 /*ARGSUSED*/
 811 static void
 812 hat_vlp_teardown(cpu_t *cpu)
 813 {
 814 #if defined(__amd64) && !defined(__xpv)
 815         struct hat_cpu_info *hci;
 816 
 817         if ((hci = cpu->cpu_hat_info) == NULL)
 818                 return;
 819         if (hci->hci_vlp_l2ptes)
 820                 kmem_free(hci->hci_vlp_l2ptes, MMU_PAGESIZE);
 821         if (hci->hci_vlp_l3ptes)
 822                 kmem_free(hci->hci_vlp_l3ptes, MMU_PAGESIZE);
 823 #endif
 824 }
 825 
 826 #define NEXT_HKR(r, l, s, e) {                  \
 827         kernel_ranges[r].hkr_level = l;         \
 828         kernel_ranges[r].hkr_start_va = s;      \
 829         kernel_ranges[r].hkr_end_va = e;        \
 830         ++r;                                    \
 831 }
 832 
 833 /*
 834  * Finish filling in the kernel hat.
 835  * Pre fill in all top level kernel page table entries for the kernel's
 836  * part of the address range.  From this point on we can't use any new
 837  * kernel large pages if they need PTE's at max_level
 838  *
 839  * create the kmap mappings.
 840  */
 841 void
 842 hat_init_finish(void)
 843 {
 844         size_t          size;
 845         uint_t          r = 0;
 846         uintptr_t       va;
 847         hat_kernel_range_t *rp;
 848 
 849 
 850         /*
 851          * We are now effectively running on the kernel hat.
 852          * Clearing use_boot_reserve shuts off using the pre-allocated boot
 853          * reserve for all HAT allocations.  From here on, the reserves are
 854          * only used when avoiding recursion in kmem_alloc().
 855          */
 856         use_boot_reserve = 0;
 857         htable_adjust_reserve();
 858 
 859         /*
 860          * User HATs are initialized with copies of all kernel mappings in
 861          * higher level page tables. Ensure that those entries exist.
 862          */
 863 #if defined(__amd64)
 864 
 865         NEXT_HKR(r, 3, kernelbase, 0);
 866 #if defined(__xpv)
 867         NEXT_HKR(r, 3, HYPERVISOR_VIRT_START, HYPERVISOR_VIRT_END);
 868 #endif
 869 
 870 #elif defined(__i386)
 871 
 872 #if !defined(__xpv)
 873         if (mmu.pae_hat) {
 874                 va = kernelbase;
 875                 if ((va & LEVEL_MASK(2)) != va) {
 876                         va = P2ROUNDUP(va, LEVEL_SIZE(2));
 877                         NEXT_HKR(r, 1, kernelbase, va);
 878                 }
 879                 if (va != 0)
 880                         NEXT_HKR(r, 2, va, 0);
 881         } else
 882 #endif /* __xpv */
 883                 NEXT_HKR(r, 1, kernelbase, 0);
 884 
 885 #endif /* __i386 */
 886 
 887         num_kernel_ranges = r;
 888 
 889         /*
 890          * Create all the kernel pagetables that will have entries
 891          * shared to user HATs.
 892          */
 893         for (r = 0; r < num_kernel_ranges; ++r) {
 894                 rp = &kernel_ranges[r];
 895                 for (va = rp->hkr_start_va; va != rp->hkr_end_va;
 896                     va += LEVEL_SIZE(rp->hkr_level)) {
 897                         htable_t *ht;
 898 
 899                         if (IN_HYPERVISOR_VA(va))
 900                                 continue;
 901 
 902                         /* can/must skip if a page mapping already exists */
 903                         if (rp->hkr_level <= mmu.max_page_level &&
 904                             (ht = htable_getpage(kas.a_hat, va, NULL)) !=
 905                             NULL) {
 906                                 htable_release(ht);
 907                                 continue;
 908                         }
 909 
 910                         (void) htable_create(kas.a_hat, va, rp->hkr_level - 1,
 911                             NULL);
 912                 }
 913         }
 914 
 915         /*
 916          * 32 bit PAE metal kernels use only 4 of the 512 entries in the
 917          * page holding the top level pagetable. We use the remainder for
 918          * the "per CPU" page tables for VLP processes.
 919          * Map the top level kernel pagetable into the kernel to make
 920          * it easy to use bcopy access these tables.
 921          */
 922         if (mmu.pae_hat) {
 923                 vlp_page = vmem_alloc(heap_arena, MMU_PAGESIZE, VM_SLEEP);
 924                 hat_devload(kas.a_hat, (caddr_t)vlp_page, MMU_PAGESIZE,
 925                     kas.a_hat->hat_htable->ht_pfn,
 926 #if !defined(__xpv)
 927                     PROT_WRITE |
 928 #endif
 929                     PROT_READ | HAT_NOSYNC | HAT_UNORDERED_OK,
 930                     HAT_LOAD | HAT_LOAD_NOCONSIST);
 931         }
 932         hat_vlp_setup(CPU);
 933 
 934         /*
 935          * Create kmap (cached mappings of kernel PTEs)
 936          * for 32 bit we map from segmap_start .. ekernelheap
 937          * for 64 bit we map from segmap_start .. segmap_start + segmapsize;
 938          */
 939 #if defined(__i386)
 940         size = (uintptr_t)ekernelheap - segmap_start;
 941 #elif defined(__amd64)
 942         size = segmapsize;
 943 #endif
 944         hat_kmap_init((uintptr_t)segmap_start, size);
 945 }
 946 
 947 /*
 948  * On 32 bit PAE mode, PTE's are 64 bits, but ordinary atomic memory references
 949  * are 32 bit, so for safety we must use atomic_cas_64() to install these.
 950  */
 951 #ifdef __i386
 952 static void
 953 reload_pae32(hat_t *hat, cpu_t *cpu)
 954 {
 955         x86pte_t *src;
 956         x86pte_t *dest;
 957         x86pte_t pte;
 958         int i;
 959 
 960         /*
 961          * Load the 4 entries of the level 2 page table into this
 962          * cpu's range of the vlp_page and point cr3 at them.
 963          */
 964         ASSERT(mmu.pae_hat);
 965         src = hat->hat_vlp_ptes;
 966         dest = vlp_page + (cpu->cpu_id + 1) * VLP_NUM_PTES;
 967         for (i = 0; i < VLP_NUM_PTES; ++i) {
 968                 for (;;) {
 969                         pte = dest[i];
 970                         if (pte == src[i])
 971                                 break;
 972                         if (atomic_cas_64(dest + i, pte, src[i]) != src[i])
 973                                 break;
 974                 }
 975         }
 976 }
 977 #endif
 978 
 979 /*
 980  * Switch to a new active hat, maintaining bit masks to track active CPUs.
 981  *
 982  * On the 32-bit PAE hypervisor, %cr3 is a 64-bit value, on metal it
 983  * remains a 32-bit value.
 984  */
 985 void
 986 hat_switch(hat_t *hat)
 987 {
 988         uint64_t        newcr3;
 989         cpu_t           *cpu = CPU;
 990         hat_t           *old = cpu->cpu_current_hat;
 991 
 992         /*
 993          * set up this information first, so we don't miss any cross calls
 994          */
 995         if (old != NULL) {
 996                 if (old == hat)
 997                         return;
 998                 if (old != kas.a_hat)
 999                         CPUSET_ATOMIC_DEL(old->hat_cpus, cpu->cpu_id);
1000         }
1001 
1002         /*
1003          * Add this CPU to the active set for this HAT.
1004          */
1005         if (hat != kas.a_hat) {
1006                 CPUSET_ATOMIC_ADD(hat->hat_cpus, cpu->cpu_id);
1007         }
1008         cpu->cpu_current_hat = hat;
1009 
1010         /*
1011          * now go ahead and load cr3
1012          */
1013         if (hat->hat_flags & HAT_VLP) {
1014 #if defined(__amd64)
1015                 x86pte_t *vlpptep = cpu->cpu_hat_info->hci_vlp_l2ptes;
1016 
1017                 VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1018                 newcr3 = MAKECR3(cpu->cpu_hat_info->hci_vlp_pfn);
1019 #elif defined(__i386)
1020                 reload_pae32(hat, cpu);
1021                 newcr3 = MAKECR3(kas.a_hat->hat_htable->ht_pfn) +
1022                     (cpu->cpu_id + 1) * VLP_SIZE;
1023 #endif
1024         } else {
1025                 newcr3 = MAKECR3((uint64_t)hat->hat_htable->ht_pfn);
1026         }
1027 #ifdef __xpv
1028         {
1029                 struct mmuext_op t[2];
1030                 uint_t retcnt;
1031                 uint_t opcnt = 1;
1032 
1033                 t[0].cmd = MMUEXT_NEW_BASEPTR;
1034                 t[0].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1035 #if defined(__amd64)
1036                 /*
1037                  * There's an interesting problem here, as to what to
1038                  * actually specify when switching to the kernel hat.
1039                  * For now we'll reuse the kernel hat again.
1040                  */
1041                 t[1].cmd = MMUEXT_NEW_USER_BASEPTR;
1042                 if (hat == kas.a_hat)
1043                         t[1].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1044                 else
1045                         t[1].arg1.mfn = pfn_to_mfn(hat->hat_user_ptable);
1046                 ++opcnt;
1047 #endif  /* __amd64 */
1048                 if (HYPERVISOR_mmuext_op(t, opcnt, &retcnt, DOMID_SELF) < 0)
1049                         panic("HYPERVISOR_mmu_update() failed");
1050                 ASSERT(retcnt == opcnt);
1051 
1052         }
1053 #else
1054         setcr3(newcr3);
1055 #endif
1056         ASSERT(cpu == CPU);
1057 }
1058 
1059 /*
1060  * Utility to return a valid x86pte_t from protections, pfn, and level number
1061  */
1062 static x86pte_t
1063 hati_mkpte(pfn_t pfn, uint_t attr, level_t level, uint_t flags)
1064 {
1065         x86pte_t        pte;
1066         uint_t          cache_attr = attr & HAT_ORDER_MASK;
1067 
1068         pte = MAKEPTE(pfn, level);
1069 
1070         if (attr & PROT_WRITE)
1071                 PTE_SET(pte, PT_WRITABLE);
1072 
1073         if (attr & PROT_USER)
1074                 PTE_SET(pte, PT_USER);
1075 
1076         if (!(attr & PROT_EXEC))
1077                 PTE_SET(pte, mmu.pt_nx);
1078 
1079         /*
1080          * Set the software bits used track ref/mod sync's and hments.
1081          * If not using REF/MOD, set them to avoid h/w rewriting PTEs.
1082          */
1083         if (flags & HAT_LOAD_NOCONSIST)
1084                 PTE_SET(pte, PT_NOCONSIST | PT_REF | PT_MOD);
1085         else if (attr & HAT_NOSYNC)
1086                 PTE_SET(pte, PT_NOSYNC | PT_REF | PT_MOD);
1087 
1088         /*
1089          * Set the caching attributes in the PTE. The combination
1090          * of attributes are poorly defined, so we pay attention
1091          * to them in the given order.
1092          *
1093          * The test for HAT_STRICTORDER is different because it's defined
1094          * as "0" - which was a stupid thing to do, but is too late to change!
1095          */
1096         if (cache_attr == HAT_STRICTORDER) {
1097                 PTE_SET(pte, PT_NOCACHE);
1098         /*LINTED [Lint hates empty ifs, but it's the obvious way to do this] */
1099         } else if (cache_attr & (HAT_UNORDERED_OK | HAT_STORECACHING_OK)) {
1100                 /* nothing to set */;
1101         } else if (cache_attr & (HAT_MERGING_OK | HAT_LOADCACHING_OK)) {
1102                 PTE_SET(pte, PT_NOCACHE);
1103                 if (is_x86_feature(x86_featureset, X86FSET_PAT))
1104                         PTE_SET(pte, (level == 0) ? PT_PAT_4K : PT_PAT_LARGE);
1105                 else
1106                         PTE_SET(pte, PT_WRITETHRU);
1107         } else {
1108                 panic("hati_mkpte(): bad caching attributes: %x\n", cache_attr);
1109         }
1110 
1111         return (pte);
1112 }
1113 
1114 /*
1115  * Duplicate address translations of the parent to the child.
1116  * This function really isn't used anymore.
1117  */
1118 /*ARGSUSED*/
1119 int
1120 hat_dup(hat_t *old, hat_t *new, caddr_t addr, size_t len, uint_t flag)
1121 {
1122         ASSERT((uintptr_t)addr < kernelbase);
1123         ASSERT(new != kas.a_hat);
1124         ASSERT(old != kas.a_hat);
1125         return (0);
1126 }
1127 
1128 /*
1129  * Allocate any hat resources required for a process being swapped in.
1130  */
1131 /*ARGSUSED*/
1132 void
1133 hat_swapin(hat_t *hat)
1134 {
1135         /* do nothing - we let everything fault back in */
1136 }
1137 
1138 /*
1139  * Unload all translations associated with an address space of a process
1140  * that is being swapped out.
1141  */
1142 void
1143 hat_swapout(hat_t *hat)
1144 {
1145         uintptr_t       vaddr = (uintptr_t)0;
1146         uintptr_t       eaddr = _userlimit;
1147         htable_t        *ht = NULL;
1148         level_t         l;
1149 
1150         XPV_DISALLOW_MIGRATE();
1151         /*
1152          * We can't just call hat_unload(hat, 0, _userlimit...)  here, because
1153          * seg_spt and shared pagetables can't be swapped out.
1154          * Take a look at segspt_shmswapout() - it's a big no-op.
1155          *
1156          * Instead we'll walk through all the address space and unload
1157          * any mappings which we are sure are not shared, not locked.
1158          */
1159         ASSERT(IS_PAGEALIGNED(vaddr));
1160         ASSERT(IS_PAGEALIGNED(eaddr));
1161         ASSERT(AS_LOCK_HELD(hat->hat_as));
1162         if ((uintptr_t)hat->hat_as->a_userlimit < eaddr)
1163                 eaddr = (uintptr_t)hat->hat_as->a_userlimit;
1164 
1165         while (vaddr < eaddr) {
1166                 (void) htable_walk(hat, &ht, &vaddr, eaddr);
1167                 if (ht == NULL)
1168                         break;
1169 
1170                 ASSERT(!IN_VA_HOLE(vaddr));
1171 
1172                 /*
1173                  * If the page table is shared skip its entire range.
1174                  */
1175                 l = ht->ht_level;
1176                 if (ht->ht_flags & HTABLE_SHARED_PFN) {
1177                         vaddr = ht->ht_vaddr + LEVEL_SIZE(l + 1);
1178                         htable_release(ht);
1179                         ht = NULL;
1180                         continue;
1181                 }
1182 
1183                 /*
1184                  * If the page table has no locked entries, unload this one.
1185                  */
1186                 if (ht->ht_lock_cnt == 0)
1187                         hat_unload(hat, (caddr_t)vaddr, LEVEL_SIZE(l),
1188                             HAT_UNLOAD_UNMAP);
1189 
1190                 /*
1191                  * If we have a level 0 page table with locked entries,
1192                  * skip the entire page table, otherwise skip just one entry.
1193                  */
1194                 if (ht->ht_lock_cnt > 0 && l == 0)
1195                         vaddr = ht->ht_vaddr + LEVEL_SIZE(1);
1196                 else
1197                         vaddr += LEVEL_SIZE(l);
1198         }
1199         if (ht)
1200                 htable_release(ht);
1201 
1202         /*
1203          * We're in swapout because the system is low on memory, so
1204          * go back and flush all the htables off the cached list.
1205          */
1206         htable_purge_hat(hat);
1207         XPV_ALLOW_MIGRATE();
1208 }
1209 
1210 /*
1211  * returns number of bytes that have valid mappings in hat.
1212  */
1213 size_t
1214 hat_get_mapped_size(hat_t *hat)
1215 {
1216         size_t total = 0;
1217         int l;
1218 
1219         for (l = 0; l <= mmu.max_page_level; l++)
1220                 total += (hat->hat_pages_mapped[l] << LEVEL_SHIFT(l));
1221         total += hat->hat_ism_pgcnt;
1222 
1223         return (total);
1224 }
1225 
1226 /*
1227  * enable/disable collection of stats for hat.
1228  */
1229 int
1230 hat_stats_enable(hat_t *hat)
1231 {
1232         atomic_inc_32(&hat->hat_stats);
1233         return (1);
1234 }
1235 
1236 void
1237 hat_stats_disable(hat_t *hat)
1238 {
1239         atomic_dec_32(&hat->hat_stats);
1240 }
1241 
1242 /*
1243  * Utility to sync the ref/mod bits from a page table entry to the page_t
1244  * We must be holding the mapping list lock when this is called.
1245  */
1246 static void
1247 hati_sync_pte_to_page(page_t *pp, x86pte_t pte, level_t level)
1248 {
1249         uint_t  rm = 0;
1250         pgcnt_t pgcnt;
1251 
1252         if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
1253                 return;
1254 
1255         if (PTE_GET(pte, PT_REF))
1256                 rm |= P_REF;
1257 
1258         if (PTE_GET(pte, PT_MOD))
1259                 rm |= P_MOD;
1260 
1261         if (rm == 0)
1262                 return;
1263 
1264         /*
1265          * sync to all constituent pages of a large page
1266          */
1267         ASSERT(x86_hm_held(pp));
1268         pgcnt = page_get_pagecnt(level);
1269         ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
1270         for (; pgcnt > 0; --pgcnt) {
1271                 /*
1272                  * hat_page_demote() can't decrease
1273                  * pszc below this mapping size
1274                  * since this large mapping existed after we
1275                  * took mlist lock.
1276                  */
1277                 ASSERT(pp->p_szc >= level);
1278                 hat_page_setattr(pp, rm);
1279                 ++pp;
1280         }
1281 }
1282 
1283 /*
1284  * This the set of PTE bits for PFN, permissions and caching
1285  * that are allowed to change on a HAT_LOAD_REMAP
1286  */
1287 #define PT_REMAP_BITS                                                   \
1288         (PT_PADDR | PT_NX | PT_WRITABLE | PT_WRITETHRU |                \
1289         PT_NOCACHE | PT_PAT_4K | PT_PAT_LARGE | PT_IGNORE | PT_REF | PT_MOD)
1290 
1291 #define REMAPASSERT(EX) if (!(EX)) panic("hati_pte_map: " #EX)
1292 /*
1293  * Do the low-level work to get a mapping entered into a HAT's pagetables
1294  * and in the mapping list of the associated page_t.
1295  */
1296 static int
1297 hati_pte_map(
1298         htable_t        *ht,
1299         uint_t          entry,
1300         page_t          *pp,
1301         x86pte_t        pte,
1302         int             flags,
1303         void            *pte_ptr)
1304 {
1305         hat_t           *hat = ht->ht_hat;
1306         x86pte_t        old_pte;
1307         level_t         l = ht->ht_level;
1308         hment_t         *hm;
1309         uint_t          is_consist;
1310         uint_t          is_locked;
1311         int             rv = 0;
1312 
1313         /*
1314          * Is this a consistent (ie. need mapping list lock) mapping?
1315          */
1316         is_consist = (pp != NULL && (flags & HAT_LOAD_NOCONSIST) == 0);
1317 
1318         /*
1319          * Track locked mapping count in the htable.  Do this first,
1320          * as we track locking even if there already is a mapping present.
1321          */
1322         is_locked = (flags & HAT_LOAD_LOCK) != 0 && hat != kas.a_hat;
1323         if (is_locked)
1324                 HTABLE_LOCK_INC(ht);
1325 
1326         /*
1327          * Acquire the page's mapping list lock and get an hment to use.
1328          * Note that hment_prepare() might return NULL.
1329          */
1330         if (is_consist) {
1331                 x86_hm_enter(pp);
1332                 hm = hment_prepare(ht, entry, pp);
1333         }
1334 
1335         /*
1336          * Set the new pte, retrieving the old one at the same time.
1337          */
1338         old_pte = x86pte_set(ht, entry, pte, pte_ptr);
1339 
1340         /*
1341          * Did we get a large page / page table collision?
1342          */
1343         if (old_pte == LPAGE_ERROR) {
1344                 if (is_locked)
1345                         HTABLE_LOCK_DEC(ht);
1346                 rv = -1;
1347                 goto done;
1348         }
1349 
1350         /*
1351          * If the mapping didn't change there is nothing more to do.
1352          */
1353         if (PTE_EQUIV(pte, old_pte))
1354                 goto done;
1355 
1356         /*
1357          * Install a new mapping in the page's mapping list
1358          */
1359         if (!PTE_ISVALID(old_pte)) {
1360                 if (is_consist) {
1361                         hment_assign(ht, entry, pp, hm);
1362                         x86_hm_exit(pp);
1363                 } else {
1364                         ASSERT(flags & HAT_LOAD_NOCONSIST);
1365                 }
1366 #if defined(__amd64)
1367                 if (ht->ht_flags & HTABLE_VLP) {
1368                         cpu_t *cpu = CPU;
1369                         x86pte_t *vlpptep = cpu->cpu_hat_info->hci_vlp_l2ptes;
1370                         VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1371                 }
1372 #endif
1373                 HTABLE_INC(ht->ht_valid_cnt);
1374                 PGCNT_INC(hat, l);
1375                 return (rv);
1376         }
1377 
1378         /*
1379          * Remap's are more complicated:
1380          *  - HAT_LOAD_REMAP must be specified if changing the pfn.
1381          *    We also require that NOCONSIST be specified.
1382          *  - Otherwise only permission or caching bits may change.
1383          */
1384         if (!PTE_ISPAGE(old_pte, l))
1385                 panic("non-null/page mapping pte=" FMT_PTE, old_pte);
1386 
1387         if (PTE2PFN(old_pte, l) != PTE2PFN(pte, l)) {
1388                 REMAPASSERT(flags & HAT_LOAD_REMAP);
1389                 REMAPASSERT(flags & HAT_LOAD_NOCONSIST);
1390                 REMAPASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
1391                 REMAPASSERT(pf_is_memory(PTE2PFN(old_pte, l)) ==
1392                     pf_is_memory(PTE2PFN(pte, l)));
1393                 REMAPASSERT(!is_consist);
1394         }
1395 
1396         /*
1397          * We only let remaps change the certain bits in the PTE.
1398          */
1399         if (PTE_GET(old_pte, ~PT_REMAP_BITS) != PTE_GET(pte, ~PT_REMAP_BITS))
1400                 panic("remap bits changed: old_pte="FMT_PTE", pte="FMT_PTE"\n",
1401                     old_pte, pte);
1402 
1403         /*
1404          * We don't create any mapping list entries on a remap, so release
1405          * any allocated hment after we drop the mapping list lock.
1406          */
1407 done:
1408         if (is_consist) {
1409                 x86_hm_exit(pp);
1410                 if (hm != NULL)
1411                         hment_free(hm);
1412         }
1413         return (rv);
1414 }
1415 
1416 /*
1417  * Internal routine to load a single page table entry. This only fails if
1418  * we attempt to overwrite a page table link with a large page.
1419  */
1420 static int
1421 hati_load_common(
1422         hat_t           *hat,
1423         uintptr_t       va,
1424         page_t          *pp,
1425         uint_t          attr,
1426         uint_t          flags,
1427         level_t         level,
1428         pfn_t           pfn)
1429 {
1430         htable_t        *ht;
1431         uint_t          entry;
1432         x86pte_t        pte;
1433         int             rv = 0;
1434 
1435         /*
1436          * The number 16 is arbitrary and here to catch a recursion problem
1437          * early before we blow out the kernel stack.
1438          */
1439         ++curthread->t_hatdepth;
1440         ASSERT(curthread->t_hatdepth < 16);
1441 
1442         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1443 
1444         if (flags & HAT_LOAD_SHARE)
1445                 hat->hat_flags |= HAT_SHARED;
1446 
1447         /*
1448          * Find the page table that maps this page if it already exists.
1449          */
1450         ht = htable_lookup(hat, va, level);
1451 
1452         /*
1453          * We must have HAT_LOAD_NOCONSIST if page_t is NULL.
1454          */
1455         if (pp == NULL)
1456                 flags |= HAT_LOAD_NOCONSIST;
1457 
1458         if (ht == NULL) {
1459                 ht = htable_create(hat, va, level, NULL);
1460                 ASSERT(ht != NULL);
1461         }
1462         entry = htable_va2entry(va, ht);
1463 
1464         /*
1465          * a bunch of paranoid error checking
1466          */
1467         ASSERT(ht->ht_busy > 0);
1468         if (ht->ht_vaddr > va || va > HTABLE_LAST_PAGE(ht))
1469                 panic("hati_load_common: bad htable %p, va %p",
1470                     (void *)ht, (void *)va);
1471         ASSERT(ht->ht_level == level);
1472 
1473         /*
1474          * construct the new PTE
1475          */
1476         if (hat == kas.a_hat)
1477                 attr &= ~PROT_USER;
1478         pte = hati_mkpte(pfn, attr, level, flags);
1479         if (hat == kas.a_hat && va >= kernelbase)
1480                 PTE_SET(pte, mmu.pt_global);
1481 
1482         /*
1483          * establish the mapping
1484          */
1485         rv = hati_pte_map(ht, entry, pp, pte, flags, NULL);
1486 
1487         /*
1488          * release the htable and any reserves
1489          */
1490         htable_release(ht);
1491         --curthread->t_hatdepth;
1492         return (rv);
1493 }
1494 
1495 /*
1496  * special case of hat_memload to deal with some kernel addrs for performance
1497  */
1498 static void
1499 hat_kmap_load(
1500         caddr_t         addr,
1501         page_t          *pp,
1502         uint_t          attr,
1503         uint_t          flags)
1504 {
1505         uintptr_t       va = (uintptr_t)addr;
1506         x86pte_t        pte;
1507         pfn_t           pfn = page_pptonum(pp);
1508         pgcnt_t         pg_off = mmu_btop(va - mmu.kmap_addr);
1509         htable_t        *ht;
1510         uint_t          entry;
1511         void            *pte_ptr;
1512 
1513         /*
1514          * construct the requested PTE
1515          */
1516         attr &= ~PROT_USER;
1517         attr |= HAT_STORECACHING_OK;
1518         pte = hati_mkpte(pfn, attr, 0, flags);
1519         PTE_SET(pte, mmu.pt_global);
1520 
1521         /*
1522          * Figure out the pte_ptr and htable and use common code to finish up
1523          */
1524         if (mmu.pae_hat)
1525                 pte_ptr = mmu.kmap_ptes + pg_off;
1526         else
1527                 pte_ptr = (x86pte32_t *)mmu.kmap_ptes + pg_off;
1528         ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr) >>
1529             LEVEL_SHIFT(1)];
1530         entry = htable_va2entry(va, ht);
1531         ++curthread->t_hatdepth;
1532         ASSERT(curthread->t_hatdepth < 16);
1533         (void) hati_pte_map(ht, entry, pp, pte, flags, pte_ptr);
1534         --curthread->t_hatdepth;
1535 }
1536 
1537 /*
1538  * hat_memload() - load a translation to the given page struct
1539  *
1540  * Flags for hat_memload/hat_devload/hat_*attr.
1541  *
1542  *      HAT_LOAD        Default flags to load a translation to the page.
1543  *
1544  *      HAT_LOAD_LOCK   Lock down mapping resources; hat_map(), hat_memload(),
1545  *                      and hat_devload().
1546  *
1547  *      HAT_LOAD_NOCONSIST Do not add mapping to page_t mapping list.
1548  *                      sets PT_NOCONSIST
1549  *
1550  *      HAT_LOAD_SHARE  A flag to hat_memload() to indicate h/w page tables
1551  *                      that map some user pages (not kas) is shared by more
1552  *                      than one process (eg. ISM).
1553  *
1554  *      HAT_LOAD_REMAP  Reload a valid pte with a different page frame.
1555  *
1556  *      HAT_NO_KALLOC   Do not kmem_alloc while creating the mapping; at this
1557  *                      point, it's setting up mapping to allocate internal
1558  *                      hat layer data structures.  This flag forces hat layer
1559  *                      to tap its reserves in order to prevent infinite
1560  *                      recursion.
1561  *
1562  * The following is a protection attribute (like PROT_READ, etc.)
1563  *
1564  *      HAT_NOSYNC      set PT_NOSYNC - this mapping's ref/mod bits
1565  *                      are never cleared.
1566  *
1567  * Installing new valid PTE's and creation of the mapping list
1568  * entry are controlled under the same lock. It's derived from the
1569  * page_t being mapped.
1570  */
1571 static uint_t supported_memload_flags =
1572         HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_ADV | HAT_LOAD_NOCONSIST |
1573         HAT_LOAD_SHARE | HAT_NO_KALLOC | HAT_LOAD_REMAP | HAT_LOAD_TEXT;
1574 
1575 void
1576 hat_memload(
1577         hat_t           *hat,
1578         caddr_t         addr,
1579         page_t          *pp,
1580         uint_t          attr,
1581         uint_t          flags)
1582 {
1583         uintptr_t       va = (uintptr_t)addr;
1584         level_t         level = 0;
1585         pfn_t           pfn = page_pptonum(pp);
1586 
1587         XPV_DISALLOW_MIGRATE();
1588         ASSERT(IS_PAGEALIGNED(va));
1589         ASSERT(hat == kas.a_hat || va < _userlimit);
1590         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1591         ASSERT((flags & supported_memload_flags) == flags);
1592 
1593         ASSERT(!IN_VA_HOLE(va));
1594         ASSERT(!PP_ISFREE(pp));
1595 
1596         /*
1597          * kernel address special case for performance.
1598          */
1599         if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
1600                 ASSERT(hat == kas.a_hat);
1601                 hat_kmap_load(addr, pp, attr, flags);
1602                 XPV_ALLOW_MIGRATE();
1603                 return;
1604         }
1605 
1606         /*
1607          * This is used for memory with normal caching enabled, so
1608          * always set HAT_STORECACHING_OK.
1609          */
1610         attr |= HAT_STORECACHING_OK;
1611         if (hati_load_common(hat, va, pp, attr, flags, level, pfn) != 0)
1612                 panic("unexpected hati_load_common() failure");
1613         XPV_ALLOW_MIGRATE();
1614 }
1615 
1616 /* ARGSUSED */
1617 void
1618 hat_memload_region(struct hat *hat, caddr_t addr, struct page *pp,
1619     uint_t attr, uint_t flags, hat_region_cookie_t rcookie)
1620 {
1621         hat_memload(hat, addr, pp, attr, flags);
1622 }
1623 
1624 /*
1625  * Load the given array of page structs using large pages when possible
1626  */
1627 void
1628 hat_memload_array(
1629         hat_t           *hat,
1630         caddr_t         addr,
1631         size_t          len,
1632         page_t          **pages,
1633         uint_t          attr,
1634         uint_t          flags)
1635 {
1636         uintptr_t       va = (uintptr_t)addr;
1637         uintptr_t       eaddr = va + len;
1638         level_t         level;
1639         size_t          pgsize;
1640         pgcnt_t         pgindx = 0;
1641         pfn_t           pfn;
1642         pgcnt_t         i;
1643 
1644         XPV_DISALLOW_MIGRATE();
1645         ASSERT(IS_PAGEALIGNED(va));
1646         ASSERT(hat == kas.a_hat || va + len <= _userlimit);
1647         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1648         ASSERT((flags & supported_memload_flags) == flags);
1649 
1650         /*
1651          * memload is used for memory with full caching enabled, so
1652          * set HAT_STORECACHING_OK.
1653          */
1654         attr |= HAT_STORECACHING_OK;
1655 
1656         /*
1657          * handle all pages using largest possible pagesize
1658          */
1659         while (va < eaddr) {
1660                 /*
1661                  * decide what level mapping to use (ie. pagesize)
1662                  */
1663                 pfn = page_pptonum(pages[pgindx]);
1664                 for (level = mmu.max_page_level; ; --level) {
1665                         pgsize = LEVEL_SIZE(level);
1666                         if (level == 0)
1667                                 break;
1668 
1669                         if (!IS_P2ALIGNED(va, pgsize) ||
1670                             (eaddr - va) < pgsize ||
1671                             !IS_P2ALIGNED(pfn_to_pa(pfn), pgsize))
1672                                 continue;
1673 
1674                         /*
1675                          * To use a large mapping of this size, all the
1676                          * pages we are passed must be sequential subpages
1677                          * of the large page.
1678                          * hat_page_demote() can't change p_szc because
1679                          * all pages are locked.
1680                          */
1681                         if (pages[pgindx]->p_szc >= level) {
1682                                 for (i = 0; i < mmu_btop(pgsize); ++i) {
1683                                         if (pfn + i !=
1684                                             page_pptonum(pages[pgindx + i]))
1685                                                 break;
1686                                         ASSERT(pages[pgindx + i]->p_szc >=
1687                                             level);
1688                                         ASSERT(pages[pgindx] + i ==
1689                                             pages[pgindx + i]);
1690                                 }
1691                                 if (i == mmu_btop(pgsize)) {
1692 #ifdef DEBUG
1693                                         if (level == 2)
1694                                                 map1gcnt++;
1695 #endif
1696                                         break;
1697                                 }
1698                         }
1699                 }
1700 
1701                 /*
1702                  * Load this page mapping. If the load fails, try a smaller
1703                  * pagesize.
1704                  */
1705                 ASSERT(!IN_VA_HOLE(va));
1706                 while (hati_load_common(hat, va, pages[pgindx], attr,
1707                     flags, level, pfn) != 0) {
1708                         if (level == 0)
1709                                 panic("unexpected hati_load_common() failure");
1710                         --level;
1711                         pgsize = LEVEL_SIZE(level);
1712                 }
1713 
1714                 /*
1715                  * move to next page
1716                  */
1717                 va += pgsize;
1718                 pgindx += mmu_btop(pgsize);
1719         }
1720         XPV_ALLOW_MIGRATE();
1721 }
1722 
1723 /* ARGSUSED */
1724 void
1725 hat_memload_array_region(struct hat *hat, caddr_t addr, size_t len,
1726     struct page **pps, uint_t attr, uint_t flags,
1727     hat_region_cookie_t rcookie)
1728 {
1729         hat_memload_array(hat, addr, len, pps, attr, flags);
1730 }
1731 
1732 /*
1733  * void hat_devload(hat, addr, len, pf, attr, flags)
1734  *      load/lock the given page frame number
1735  *
1736  * Advisory ordering attributes. Apply only to device mappings.
1737  *
1738  * HAT_STRICTORDER: the CPU must issue the references in order, as the
1739  *      programmer specified.  This is the default.
1740  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
1741  *      of reordering; store or load with store or load).
1742  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
1743  *      to consecutive locations (for example, turn two consecutive byte
1744  *      stores into one halfword store), and it may batch individual loads
1745  *      (for example, turn two consecutive byte loads into one halfword load).
1746  *      This also implies re-ordering.
1747  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
1748  *      until another store occurs.  The default is to fetch new data
1749  *      on every load.  This also implies merging.
1750  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
1751  *      the device (perhaps with other data) at a later time.  The default is
1752  *      to push the data right away.  This also implies load caching.
1753  *
1754  * Equivalent of hat_memload(), but can be used for device memory where
1755  * there are no page_t's and we support additional flags (write merging, etc).
1756  * Note that we can have large page mappings with this interface.
1757  */
1758 int supported_devload_flags = HAT_LOAD | HAT_LOAD_LOCK |
1759         HAT_LOAD_NOCONSIST | HAT_STRICTORDER | HAT_UNORDERED_OK |
1760         HAT_MERGING_OK | HAT_LOADCACHING_OK | HAT_STORECACHING_OK;
1761 
1762 void
1763 hat_devload(
1764         hat_t           *hat,
1765         caddr_t         addr,
1766         size_t          len,
1767         pfn_t           pfn,
1768         uint_t          attr,
1769         int             flags)
1770 {
1771         uintptr_t       va = ALIGN2PAGE(addr);
1772         uintptr_t       eva = va + len;
1773         level_t         level;
1774         size_t          pgsize;
1775         page_t          *pp;
1776         int             f;      /* per PTE copy of flags  - maybe modified */
1777         uint_t          a;      /* per PTE copy of attr */
1778 
1779         XPV_DISALLOW_MIGRATE();
1780         ASSERT(IS_PAGEALIGNED(va));
1781         ASSERT(hat == kas.a_hat || eva <= _userlimit);
1782         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1783         ASSERT((flags & supported_devload_flags) == flags);
1784 
1785         /*
1786          * handle all pages
1787          */
1788         while (va < eva) {
1789 
1790                 /*
1791                  * decide what level mapping to use (ie. pagesize)
1792                  */
1793                 for (level = mmu.max_page_level; ; --level) {
1794                         pgsize = LEVEL_SIZE(level);
1795                         if (level == 0)
1796                                 break;
1797                         if (IS_P2ALIGNED(va, pgsize) &&
1798                             (eva - va) >= pgsize &&
1799                             IS_P2ALIGNED(pfn, mmu_btop(pgsize))) {
1800 #ifdef DEBUG
1801                                 if (level == 2)
1802                                         map1gcnt++;
1803 #endif
1804                                 break;
1805                         }
1806                 }
1807 
1808                 /*
1809                  * If this is just memory then allow caching (this happens
1810                  * for the nucleus pages) - though HAT_PLAT_NOCACHE can be used
1811                  * to override that. If we don't have a page_t then make sure
1812                  * NOCONSIST is set.
1813                  */
1814                 a = attr;
1815                 f = flags;
1816                 if (!pf_is_memory(pfn))
1817                         f |= HAT_LOAD_NOCONSIST;
1818                 else if (!(a & HAT_PLAT_NOCACHE))
1819                         a |= HAT_STORECACHING_OK;
1820 
1821                 if (f & HAT_LOAD_NOCONSIST)
1822                         pp = NULL;
1823                 else
1824                         pp = page_numtopp_nolock(pfn);
1825 
1826                 /*
1827                  * Check to make sure we are really trying to map a valid
1828                  * memory page. The caller wishing to intentionally map
1829                  * free memory pages will have passed the HAT_LOAD_NOCONSIST
1830                  * flag, then pp will be NULL.
1831                  */
1832                 if (pp != NULL) {
1833                         if (PP_ISFREE(pp)) {
1834                                 panic("hat_devload: loading "
1835                                     "a mapping to free page %p", (void *)pp);
1836                         }
1837 
1838                         if (!PAGE_LOCKED(pp) && !PP_ISNORELOC(pp)) {
1839                                 panic("hat_devload: loading a mapping "
1840                                     "to an unlocked page %p",
1841                                     (void *)pp);
1842                         }
1843                 }
1844 
1845                 /*
1846                  * load this page mapping
1847                  */
1848                 ASSERT(!IN_VA_HOLE(va));
1849                 while (hati_load_common(hat, va, pp, a, f, level, pfn) != 0) {
1850                         if (level == 0)
1851                                 panic("unexpected hati_load_common() failure");
1852                         --level;
1853                         pgsize = LEVEL_SIZE(level);
1854                 }
1855 
1856                 /*
1857                  * move to next page
1858                  */
1859                 va += pgsize;
1860                 pfn += mmu_btop(pgsize);
1861         }
1862         XPV_ALLOW_MIGRATE();
1863 }
1864 
1865 /*
1866  * void hat_unlock(hat, addr, len)
1867  *      unlock the mappings to a given range of addresses
1868  *
1869  * Locks are tracked by ht_lock_cnt in the htable.
1870  */
1871 void
1872 hat_unlock(hat_t *hat, caddr_t addr, size_t len)
1873 {
1874         uintptr_t       vaddr = (uintptr_t)addr;
1875         uintptr_t       eaddr = vaddr + len;
1876         htable_t        *ht = NULL;
1877 
1878         /*
1879          * kernel entries are always locked, we don't track lock counts
1880          */
1881         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
1882         ASSERT(IS_PAGEALIGNED(vaddr));
1883         ASSERT(IS_PAGEALIGNED(eaddr));
1884         if (hat == kas.a_hat)
1885                 return;
1886         if (eaddr > _userlimit)
1887                 panic("hat_unlock() address out of range - above _userlimit");
1888 
1889         XPV_DISALLOW_MIGRATE();
1890         ASSERT(AS_LOCK_HELD(hat->hat_as));
1891         while (vaddr < eaddr) {
1892                 (void) htable_walk(hat, &ht, &vaddr, eaddr);
1893                 if (ht == NULL)
1894                         break;
1895 
1896                 ASSERT(!IN_VA_HOLE(vaddr));
1897 
1898                 if (ht->ht_lock_cnt < 1)
1899                         panic("hat_unlock(): lock_cnt < 1, "
1900                             "htable=%p, vaddr=%p\n", (void *)ht, (void *)vaddr);
1901                 HTABLE_LOCK_DEC(ht);
1902 
1903                 vaddr += LEVEL_SIZE(ht->ht_level);
1904         }
1905         if (ht)
1906                 htable_release(ht);
1907         XPV_ALLOW_MIGRATE();
1908 }
1909 
1910 /* ARGSUSED */
1911 void
1912 hat_unlock_region(struct hat *hat, caddr_t addr, size_t len,
1913     hat_region_cookie_t rcookie)
1914 {
1915         panic("No shared region support on x86");
1916 }
1917 
1918 /*
1919  * A range of virtual pages for purposes of demapping.
1920  */
1921 typedef struct range_info {
1922         uintptr_t       rng_va;         /* address of page */
1923         ulong_t         rng_cnt;        /* number of pages in range */
1924         level_t         rng_level;      /* page table level */
1925 } range_info_t;
1926 
1927 #if !defined(__xpv)
1928 /*
1929  * Cross call service routine to demap a range of virtual
1930  * pages on the current CPU or flush all mappings in TLB.
1931  */
1932 /*ARGSUSED*/
1933 static int
1934 hati_demap_func(xc_arg_t a1, xc_arg_t a2, xc_arg_t a3)
1935 {
1936         hat_t           *hat = (hat_t *)a1;
1937         range_info_t    *range = (range_info_t *)a2;
1938         size_t          len = (size_t)a3;
1939         caddr_t         addr = (caddr_t)range->rng_va;
1940         size_t          pgsz = LEVEL_SIZE(range->rng_level);
1941 
1942         /*
1943          * If the target hat isn't the kernel and this CPU isn't operating
1944          * in the target hat, we can ignore the cross call.
1945          */
1946         if (hat != kas.a_hat && hat != CPU->cpu_current_hat)
1947                 return (0);
1948 
1949         /*
1950          * For a normal address, we flush a range of contiguous mappings
1951          */
1952         if ((uintptr_t)addr != DEMAP_ALL_ADDR) {
1953                 for (size_t i = 0; i < len; i += pgsz)
1954                         mmu_tlbflush_entry(addr + i);
1955                 return (0);
1956         }
1957 
1958         /*
1959          * Otherwise we reload cr3 to effect a complete TLB flush.
1960          *
1961          * A reload of cr3 on a VLP process also means we must also recopy in
1962          * the pte values from the struct hat
1963          */
1964         if (hat->hat_flags & HAT_VLP) {
1965 #if defined(__amd64)
1966                 x86pte_t *vlpptep = CPU->cpu_hat_info->hci_vlp_l2ptes;
1967 
1968                 VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1969 #elif defined(__i386)
1970                 reload_pae32(hat, CPU);
1971 #endif
1972         }
1973         reload_cr3();
1974         return (0);
1975 }
1976 
1977 /*
1978  * Flush all TLB entries, including global (ie. kernel) ones.
1979  */
1980 static void
1981 flush_all_tlb_entries(void)
1982 {
1983         ulong_t cr4 = getcr4();
1984 
1985         if (cr4 & CR4_PGE) {
1986                 setcr4(cr4 & ~(ulong_t)CR4_PGE);
1987                 setcr4(cr4);
1988 
1989                 /*
1990                  * 32 bit PAE also needs to always reload_cr3()
1991                  */
1992                 if (mmu.max_level == 2)
1993                         reload_cr3();
1994         } else {
1995                 reload_cr3();
1996         }
1997 }
1998 
1999 #define TLB_CPU_HALTED  (01ul)
2000 #define TLB_INVAL_ALL   (02ul)
2001 #define CAS_TLB_INFO(cpu, old, new)     \
2002         atomic_cas_ulong((ulong_t *)&(cpu)->cpu_m.mcpu_tlb_info, (old), (new))
2003 
2004 /*
2005  * Record that a CPU is going idle
2006  */
2007 void
2008 tlb_going_idle(void)
2009 {
2010         atomic_or_ulong((ulong_t *)&CPU->cpu_m.mcpu_tlb_info, TLB_CPU_HALTED);
2011 }
2012 
2013 /*
2014  * Service a delayed TLB flush if coming out of being idle.
2015  * It will be called from cpu idle notification with interrupt disabled.
2016  */
2017 void
2018 tlb_service(void)
2019 {
2020         ulong_t tlb_info;
2021         ulong_t found;
2022 
2023         /*
2024          * We only have to do something if coming out of being idle.
2025          */
2026         tlb_info = CPU->cpu_m.mcpu_tlb_info;
2027         if (tlb_info & TLB_CPU_HALTED) {
2028                 ASSERT(CPU->cpu_current_hat == kas.a_hat);
2029 
2030                 /*
2031                  * Atomic clear and fetch of old state.
2032                  */
2033                 while ((found = CAS_TLB_INFO(CPU, tlb_info, 0)) != tlb_info) {
2034                         ASSERT(found & TLB_CPU_HALTED);
2035                         tlb_info = found;
2036                         SMT_PAUSE();
2037                 }
2038                 if (tlb_info & TLB_INVAL_ALL)
2039                         flush_all_tlb_entries();
2040         }
2041 }
2042 #endif /* !__xpv */
2043 
2044 /*
2045  * Internal routine to do cross calls to invalidate a range of pages on
2046  * all CPUs using a given hat.
2047  */
2048 void
2049 hat_tlb_inval_range(hat_t *hat, range_info_t *range)
2050 {
2051         extern int      flushes_require_xcalls; /* from mp_startup.c */
2052         cpuset_t        justme;
2053         cpuset_t        cpus_to_shootdown;
2054         uintptr_t       va = range->rng_va;
2055         size_t          len = range->rng_cnt << LEVEL_SHIFT(range->rng_level);
2056 #ifndef __xpv
2057         cpuset_t        check_cpus;
2058         cpu_t           *cpup;
2059         int             c;
2060 #endif
2061 
2062         /*
2063          * If the hat is being destroyed, there are no more users, so
2064          * demap need not do anything.
2065          */
2066         if (hat->hat_flags & HAT_FREEING)
2067                 return;
2068 
2069         /*
2070          * If demapping from a shared pagetable, we best demap the
2071          * entire set of user TLBs, since we don't know what addresses
2072          * these were shared at.
2073          */
2074         if (hat->hat_flags & HAT_SHARED) {
2075                 hat = kas.a_hat;
2076                 va = DEMAP_ALL_ADDR;
2077         }
2078 
2079         /*
2080          * if not running with multiple CPUs, don't use cross calls
2081          */
2082         if (panicstr || !flushes_require_xcalls) {
2083 #ifdef __xpv
2084                 if (va == DEMAP_ALL_ADDR) {
2085                         xen_flush_tlb();
2086                 } else {
2087                         for (size_t i = 0; i < len; i += MMU_PAGESIZE)
2088                                 xen_flush_va((caddr_t)(va + i));
2089                 }
2090 #else
2091                 (void) hati_demap_func((xc_arg_t)hat,
2092                     (xc_arg_t)range, (xc_arg_t)len);
2093 #endif
2094                 return;
2095         }
2096 
2097 
2098         /*
2099          * Determine CPUs to shootdown. Kernel changes always do all CPUs.
2100          * Otherwise it's just CPUs currently executing in this hat.
2101          */
2102         kpreempt_disable();
2103         CPUSET_ONLY(justme, CPU->cpu_id);
2104         if (hat == kas.a_hat)
2105                 cpus_to_shootdown = khat_cpuset;
2106         else
2107                 cpus_to_shootdown = hat->hat_cpus;
2108 
2109 #ifndef __xpv
2110         /*
2111          * If any CPUs in the set are idle, just request a delayed flush
2112          * and avoid waking them up.
2113          */
2114         check_cpus = cpus_to_shootdown;
2115         for (c = 0; c < NCPU && !CPUSET_ISNULL(check_cpus); ++c) {
2116                 ulong_t tlb_info;
2117 
2118                 if (!CPU_IN_SET(check_cpus, c))
2119                         continue;
2120                 CPUSET_DEL(check_cpus, c);
2121                 cpup = cpu[c];
2122                 if (cpup == NULL)
2123                         continue;
2124 
2125                 tlb_info = cpup->cpu_m.mcpu_tlb_info;
2126                 while (tlb_info == TLB_CPU_HALTED) {
2127                         (void) CAS_TLB_INFO(cpup, TLB_CPU_HALTED,
2128                             TLB_CPU_HALTED | TLB_INVAL_ALL);
2129                         SMT_PAUSE();
2130                         tlb_info = cpup->cpu_m.mcpu_tlb_info;
2131                 }
2132                 if (tlb_info == (TLB_CPU_HALTED | TLB_INVAL_ALL)) {
2133                         HATSTAT_INC(hs_tlb_inval_delayed);
2134                         CPUSET_DEL(cpus_to_shootdown, c);
2135                 }
2136         }
2137 #endif
2138 
2139         if (CPUSET_ISNULL(cpus_to_shootdown) ||
2140             CPUSET_ISEQUAL(cpus_to_shootdown, justme)) {
2141 
2142 #ifdef __xpv
2143                 if (va == DEMAP_ALL_ADDR) {
2144                         xen_flush_tlb();
2145                 } else {
2146                         for (size_t i = 0; i < len; i += MMU_PAGESIZE)
2147                                 xen_flush_va((caddr_t)(va + i));
2148                 }
2149 #else
2150                 (void) hati_demap_func((xc_arg_t)hat,
2151                     (xc_arg_t)range, (xc_arg_t)len);
2152 #endif
2153 
2154         } else {
2155 
2156                 CPUSET_ADD(cpus_to_shootdown, CPU->cpu_id);
2157 #ifdef __xpv
2158                 if (va == DEMAP_ALL_ADDR) {
2159                         xen_gflush_tlb(cpus_to_shootdown);
2160                 } else {
2161                         for (size_t i = 0; i < len; i += MMU_PAGESIZE) {
2162                                 xen_gflush_va((caddr_t)(va + i),
2163                                     cpus_to_shootdown);
2164                         }
2165                 }
2166 #else
2167                 xc_call((xc_arg_t)hat, (xc_arg_t)range, (xc_arg_t)len,
2168                     CPUSET2BV(cpus_to_shootdown), hati_demap_func);
2169 #endif
2170 
2171         }
2172         kpreempt_enable();
2173 }
2174 
2175 void
2176 hat_tlb_inval(hat_t *hat, uintptr_t va)
2177 {
2178         /*
2179          * Create range for a single page.
2180          */
2181         range_info_t range;
2182         range.rng_va = va;
2183         range.rng_cnt = 1; /* one page */
2184         range.rng_level = MIN_PAGE_LEVEL; /* pages are MMU_PAGESIZE */
2185 
2186         hat_tlb_inval_range(hat, &range);
2187 }
2188 
2189 /*
2190  * Interior routine for HAT_UNLOADs from hat_unload_callback(),
2191  * hat_kmap_unload() OR from hat_steal() code.  This routine doesn't
2192  * handle releasing of the htables.
2193  */
2194 void
2195 hat_pte_unmap(
2196         htable_t        *ht,
2197         uint_t          entry,
2198         uint_t          flags,
2199         x86pte_t        old_pte,
2200         void            *pte_ptr,
2201         boolean_t       tlb)
2202 {
2203         hat_t           *hat = ht->ht_hat;
2204         hment_t         *hm = NULL;
2205         page_t          *pp = NULL;
2206         level_t         l = ht->ht_level;
2207         pfn_t           pfn;
2208 
2209         /*
2210          * We always track the locking counts, even if nothing is unmapped
2211          */
2212         if ((flags & HAT_UNLOAD_UNLOCK) != 0 && hat != kas.a_hat) {
2213                 ASSERT(ht->ht_lock_cnt > 0);
2214                 HTABLE_LOCK_DEC(ht);
2215         }
2216 
2217         /*
2218          * Figure out which page's mapping list lock to acquire using the PFN
2219          * passed in "old" PTE. We then attempt to invalidate the PTE.
2220          * If another thread, probably a hat_pageunload, has asynchronously
2221          * unmapped/remapped this address we'll loop here.
2222          */
2223         ASSERT(ht->ht_busy > 0);
2224         while (PTE_ISVALID(old_pte)) {
2225                 pfn = PTE2PFN(old_pte, l);
2226                 if (PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST) {
2227                         pp = NULL;
2228                 } else {
2229 #ifdef __xpv
2230                         if (pfn == PFN_INVALID)
2231                                 panic("Invalid PFN, but not PT_NOCONSIST");
2232 #endif
2233                         pp = page_numtopp_nolock(pfn);
2234                         if (pp == NULL) {
2235                                 panic("no page_t, not NOCONSIST: old_pte="
2236                                     FMT_PTE " ht=%lx entry=0x%x pte_ptr=%lx",
2237                                     old_pte, (uintptr_t)ht, entry,
2238                                     (uintptr_t)pte_ptr);
2239                         }
2240                         x86_hm_enter(pp);
2241                 }
2242 
2243                 old_pte = x86pte_inval(ht, entry, old_pte, pte_ptr, tlb);
2244 
2245                 /*
2246                  * If the page hadn't changed we've unmapped it and can proceed
2247                  */
2248                 if (PTE_ISVALID(old_pte) && PTE2PFN(old_pte, l) == pfn)
2249                         break;
2250 
2251                 /*
2252                  * Otherwise, we'll have to retry with the current old_pte.
2253                  * Drop the hment lock, since the pfn may have changed.
2254                  */
2255                 if (pp != NULL) {
2256                         x86_hm_exit(pp);
2257                         pp = NULL;
2258                 } else {
2259                         ASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
2260                 }
2261         }
2262 
2263         /*
2264          * If the old mapping wasn't valid, there's nothing more to do
2265          */
2266         if (!PTE_ISVALID(old_pte)) {
2267                 if (pp != NULL)
2268                         x86_hm_exit(pp);
2269                 return;
2270         }
2271 
2272         /*
2273          * Take care of syncing any MOD/REF bits and removing the hment.
2274          */
2275         if (pp != NULL) {
2276                 if (!(flags & HAT_UNLOAD_NOSYNC))
2277                         hati_sync_pte_to_page(pp, old_pte, l);
2278                 hm = hment_remove(pp, ht, entry);
2279                 x86_hm_exit(pp);
2280                 if (hm != NULL)
2281                         hment_free(hm);
2282         }
2283 
2284         /*
2285          * Handle book keeping in the htable and hat
2286          */
2287         ASSERT(ht->ht_valid_cnt > 0);
2288         HTABLE_DEC(ht->ht_valid_cnt);
2289         PGCNT_DEC(hat, l);
2290 }
2291 
2292 /*
2293  * very cheap unload implementation to special case some kernel addresses
2294  */
2295 static void
2296 hat_kmap_unload(caddr_t addr, size_t len, uint_t flags)
2297 {
2298         uintptr_t       va = (uintptr_t)addr;
2299         uintptr_t       eva = va + len;
2300         pgcnt_t         pg_index;
2301         htable_t        *ht;
2302         uint_t          entry;
2303         x86pte_t        *pte_ptr;
2304         x86pte_t        old_pte;
2305 
2306         for (; va < eva; va += MMU_PAGESIZE) {
2307                 /*
2308                  * Get the PTE
2309                  */
2310                 pg_index = mmu_btop(va - mmu.kmap_addr);
2311                 pte_ptr = PT_INDEX_PTR(mmu.kmap_ptes, pg_index);
2312                 old_pte = GET_PTE(pte_ptr);
2313 
2314                 /*
2315                  * get the htable / entry
2316                  */
2317                 ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr)
2318                     >> LEVEL_SHIFT(1)];
2319                 entry = htable_va2entry(va, ht);
2320 
2321                 /*
2322                  * use mostly common code to unmap it.
2323                  */
2324                 hat_pte_unmap(ht, entry, flags, old_pte, pte_ptr, B_TRUE);
2325         }
2326 }
2327 
2328 
2329 /*
2330  * unload a range of virtual address space (no callback)
2331  */
2332 void
2333 hat_unload(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2334 {
2335         uintptr_t va = (uintptr_t)addr;
2336 
2337         XPV_DISALLOW_MIGRATE();
2338         ASSERT(hat == kas.a_hat || va + len <= _userlimit);
2339 
2340         /*
2341          * special case for performance.
2342          */
2343         if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
2344                 ASSERT(hat == kas.a_hat);
2345                 hat_kmap_unload(addr, len, flags);
2346         } else {
2347                 hat_unload_callback(hat, addr, len, flags, NULL);
2348         }
2349         XPV_ALLOW_MIGRATE();
2350 }
2351 
2352 /*
2353  * Invalidate the TLB, and perform the callback to the upper level VM system,
2354  * for the specified ranges of contiguous pages.
2355  */
2356 static void
2357 handle_ranges(hat_t *hat, hat_callback_t *cb, uint_t cnt, range_info_t *range)
2358 {
2359         while (cnt > 0) {
2360                 --cnt;
2361                 hat_tlb_inval_range(hat, &range[cnt]);
2362 
2363                 if (cb != NULL) {
2364                         cb->hcb_start_addr = (caddr_t)range[cnt].rng_va;
2365                         cb->hcb_end_addr = cb->hcb_start_addr;
2366                         cb->hcb_end_addr += range[cnt].rng_cnt <<
2367                             LEVEL_SHIFT(range[cnt].rng_level);
2368                         cb->hcb_function(cb);
2369                 }
2370         }
2371 }
2372 
2373 /*
2374  * Unload a given range of addresses (has optional callback)
2375  *
2376  * Flags:
2377  * define       HAT_UNLOAD              0x00
2378  * define       HAT_UNLOAD_NOSYNC       0x02
2379  * define       HAT_UNLOAD_UNLOCK       0x04
2380  * define       HAT_UNLOAD_OTHER        0x08 - not used
2381  * define       HAT_UNLOAD_UNMAP        0x10 - same as HAT_UNLOAD
2382  */
2383 #define MAX_UNLOAD_CNT (8)
2384 void
2385 hat_unload_callback(
2386         hat_t           *hat,
2387         caddr_t         addr,
2388         size_t          len,
2389         uint_t          flags,
2390         hat_callback_t  *cb)
2391 {
2392         uintptr_t       vaddr = (uintptr_t)addr;
2393         uintptr_t       eaddr = vaddr + len;
2394         htable_t        *ht = NULL;
2395         uint_t          entry;
2396         uintptr_t       contig_va = (uintptr_t)-1L;
2397         range_info_t    r[MAX_UNLOAD_CNT];
2398         uint_t          r_cnt = 0;
2399         x86pte_t        old_pte;
2400 
2401         XPV_DISALLOW_MIGRATE();
2402         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2403         ASSERT(IS_PAGEALIGNED(vaddr));
2404         ASSERT(IS_PAGEALIGNED(eaddr));
2405 
2406         /*
2407          * Special case a single page being unloaded for speed. This happens
2408          * quite frequently, COW faults after a fork() for example.
2409          */
2410         if (cb == NULL && len == MMU_PAGESIZE) {
2411                 ht = htable_getpte(hat, vaddr, &entry, &old_pte, 0);
2412                 if (ht != NULL) {
2413                         if (PTE_ISVALID(old_pte)) {
2414                                 hat_pte_unmap(ht, entry, flags, old_pte,
2415                                     NULL, B_TRUE);
2416                         }
2417                         htable_release(ht);
2418                 }
2419                 XPV_ALLOW_MIGRATE();
2420                 return;
2421         }
2422 
2423         while (vaddr < eaddr) {
2424                 old_pte = htable_walk(hat, &ht, &vaddr, eaddr);
2425                 if (ht == NULL)
2426                         break;
2427 
2428                 ASSERT(!IN_VA_HOLE(vaddr));
2429 
2430                 if (vaddr < (uintptr_t)addr)
2431                         panic("hat_unload_callback(): unmap inside large page");
2432 
2433                 /*
2434                  * We'll do the call backs for contiguous ranges
2435                  */
2436                 if (vaddr != contig_va ||
2437                     (r_cnt > 0 && r[r_cnt - 1].rng_level != ht->ht_level)) {
2438                         if (r_cnt == MAX_UNLOAD_CNT) {
2439                                 handle_ranges(hat, cb, r_cnt, r);
2440                                 r_cnt = 0;
2441                         }
2442                         r[r_cnt].rng_va = vaddr;
2443                         r[r_cnt].rng_cnt = 0;
2444                         r[r_cnt].rng_level = ht->ht_level;
2445                         ++r_cnt;
2446                 }
2447 
2448                 /*
2449                  * Unload one mapping (for a single page) from the page tables.
2450                  * Note that we do not remove the mapping from the TLB yet,
2451                  * as indicated by the tlb=FALSE argument to hat_pte_unmap().
2452                  * handle_ranges() will clear the TLB entries with one call to
2453                  * hat_tlb_inval_range() per contiguous range.  This is
2454                  * safe because the page can not be reused until the
2455                  * callback is made (or we return).
2456                  */
2457                 entry = htable_va2entry(vaddr, ht);
2458                 hat_pte_unmap(ht, entry, flags, old_pte, NULL, B_FALSE);
2459                 ASSERT(ht->ht_level <= mmu.max_page_level);
2460                 vaddr += LEVEL_SIZE(ht->ht_level);
2461                 contig_va = vaddr;
2462                 ++r[r_cnt - 1].rng_cnt;
2463         }
2464         if (ht)
2465                 htable_release(ht);
2466 
2467         /*
2468          * handle last range for callbacks
2469          */
2470         if (r_cnt > 0)
2471                 handle_ranges(hat, cb, r_cnt, r);
2472         XPV_ALLOW_MIGRATE();
2473 }
2474 
2475 /*
2476  * Invalidate a virtual address translation on a slave CPU during
2477  * panic() dumps.
2478  */
2479 void
2480 hat_flush_range(hat_t *hat, caddr_t va, size_t size)
2481 {
2482         ssize_t sz;
2483         caddr_t endva = va + size;
2484 
2485         while (va < endva) {
2486                 sz = hat_getpagesize(hat, va);
2487                 if (sz < 0) {
2488 #ifdef __xpv
2489                         xen_flush_tlb();
2490 #else
2491                         flush_all_tlb_entries();
2492 #endif
2493                         break;
2494                 }
2495 #ifdef __xpv
2496                 xen_flush_va(va);
2497 #else
2498                 mmu_tlbflush_entry(va);
2499 #endif
2500                 va += sz;
2501         }
2502 }
2503 
2504 /*
2505  * synchronize mapping with software data structures
2506  *
2507  * This interface is currently only used by the working set monitor
2508  * driver.
2509  */
2510 /*ARGSUSED*/
2511 void
2512 hat_sync(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2513 {
2514         uintptr_t       vaddr = (uintptr_t)addr;
2515         uintptr_t       eaddr = vaddr + len;
2516         htable_t        *ht = NULL;
2517         uint_t          entry;
2518         x86pte_t        pte;
2519         x86pte_t        save_pte;
2520         x86pte_t        new;
2521         page_t          *pp;
2522 
2523         ASSERT(!IN_VA_HOLE(vaddr));
2524         ASSERT(IS_PAGEALIGNED(vaddr));
2525         ASSERT(IS_PAGEALIGNED(eaddr));
2526         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2527 
2528         XPV_DISALLOW_MIGRATE();
2529         for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2530 try_again:
2531                 pte = htable_walk(hat, &ht, &vaddr, eaddr);
2532                 if (ht == NULL)
2533                         break;
2534                 entry = htable_va2entry(vaddr, ht);
2535 
2536                 if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2537                     PTE_GET(pte, PT_REF | PT_MOD) == 0)
2538                         continue;
2539 
2540                 /*
2541                  * We need to acquire the mapping list lock to protect
2542                  * against hat_pageunload(), hat_unload(), etc.
2543                  */
2544                 pp = page_numtopp_nolock(PTE2PFN(pte, ht->ht_level));
2545                 if (pp == NULL)
2546                         break;
2547                 x86_hm_enter(pp);
2548                 save_pte = pte;
2549                 pte = x86pte_get(ht, entry);
2550                 if (pte != save_pte) {
2551                         x86_hm_exit(pp);
2552                         goto try_again;
2553                 }
2554                 if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2555                     PTE_GET(pte, PT_REF | PT_MOD) == 0) {
2556                         x86_hm_exit(pp);
2557                         continue;
2558                 }
2559 
2560                 /*
2561                  * Need to clear ref or mod bits. We may compete with
2562                  * hardware updating the R/M bits and have to try again.
2563                  */
2564                 if (flags == HAT_SYNC_ZERORM) {
2565                         new = pte;
2566                         PTE_CLR(new, PT_REF | PT_MOD);
2567                         pte = hati_update_pte(ht, entry, pte, new);
2568                         if (pte != 0) {
2569                                 x86_hm_exit(pp);
2570                                 goto try_again;
2571                         }
2572                 } else {
2573                         /*
2574                          * sync the PTE to the page_t
2575                          */
2576                         hati_sync_pte_to_page(pp, save_pte, ht->ht_level);
2577                 }
2578                 x86_hm_exit(pp);
2579         }
2580         if (ht)
2581                 htable_release(ht);
2582         XPV_ALLOW_MIGRATE();
2583 }
2584 
2585 /*
2586  * void hat_map(hat, addr, len, flags)
2587  */
2588 /*ARGSUSED*/
2589 void
2590 hat_map(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2591 {
2592         /* does nothing */
2593 }
2594 
2595 /*
2596  * uint_t hat_getattr(hat, addr, *attr)
2597  *      returns attr for <hat,addr> in *attr.  returns 0 if there was a
2598  *      mapping and *attr is valid, nonzero if there was no mapping and
2599  *      *attr is not valid.
2600  */
2601 uint_t
2602 hat_getattr(hat_t *hat, caddr_t addr, uint_t *attr)
2603 {
2604         uintptr_t       vaddr = ALIGN2PAGE(addr);
2605         htable_t        *ht = NULL;
2606         x86pte_t        pte;
2607 
2608         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2609 
2610         if (IN_VA_HOLE(vaddr))
2611                 return ((uint_t)-1);
2612 
2613         ht = htable_getpte(hat, vaddr, NULL, &pte, mmu.max_page_level);
2614         if (ht == NULL)
2615                 return ((uint_t)-1);
2616 
2617         if (!PTE_ISVALID(pte) || !PTE_ISPAGE(pte, ht->ht_level)) {
2618                 htable_release(ht);
2619                 return ((uint_t)-1);
2620         }
2621 
2622         *attr = PROT_READ;
2623         if (PTE_GET(pte, PT_WRITABLE))
2624                 *attr |= PROT_WRITE;
2625         if (PTE_GET(pte, PT_USER))
2626                 *attr |= PROT_USER;
2627         if (!PTE_GET(pte, mmu.pt_nx))
2628                 *attr |= PROT_EXEC;
2629         if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
2630                 *attr |= HAT_NOSYNC;
2631         htable_release(ht);
2632         return (0);
2633 }
2634 
2635 /*
2636  * hat_updateattr() applies the given attribute change to an existing mapping
2637  */
2638 #define HAT_LOAD_ATTR           1
2639 #define HAT_SET_ATTR            2
2640 #define HAT_CLR_ATTR            3
2641 
2642 static void
2643 hat_updateattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr, int what)
2644 {
2645         uintptr_t       vaddr = (uintptr_t)addr;
2646         uintptr_t       eaddr = (uintptr_t)addr + len;
2647         htable_t        *ht = NULL;
2648         uint_t          entry;
2649         x86pte_t        oldpte, newpte;
2650         page_t          *pp;
2651 
2652         XPV_DISALLOW_MIGRATE();
2653         ASSERT(IS_PAGEALIGNED(vaddr));
2654         ASSERT(IS_PAGEALIGNED(eaddr));
2655         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2656         for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2657 try_again:
2658                 oldpte = htable_walk(hat, &ht, &vaddr, eaddr);
2659                 if (ht == NULL)
2660                         break;
2661                 if (PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOCONSIST)
2662                         continue;
2663 
2664                 pp = page_numtopp_nolock(PTE2PFN(oldpte, ht->ht_level));
2665                 if (pp == NULL)
2666                         continue;
2667                 x86_hm_enter(pp);
2668 
2669                 newpte = oldpte;
2670                 /*
2671                  * We found a page table entry in the desired range,
2672                  * figure out the new attributes.
2673                  */
2674                 if (what == HAT_SET_ATTR || what == HAT_LOAD_ATTR) {
2675                         if ((attr & PROT_WRITE) &&
2676                             !PTE_GET(oldpte, PT_WRITABLE))
2677                                 newpte |= PT_WRITABLE;
2678 
2679                         if ((attr & HAT_NOSYNC) &&
2680                             PTE_GET(oldpte, PT_SOFTWARE) < PT_NOSYNC)
2681                                 newpte |= PT_NOSYNC;
2682 
2683                         if ((attr & PROT_EXEC) && PTE_GET(oldpte, mmu.pt_nx))
2684                                 newpte &= ~mmu.pt_nx;
2685                 }
2686 
2687                 if (what == HAT_LOAD_ATTR) {
2688                         if (!(attr & PROT_WRITE) &&
2689                             PTE_GET(oldpte, PT_WRITABLE))
2690                                 newpte &= ~PT_WRITABLE;
2691 
2692                         if (!(attr & HAT_NOSYNC) &&
2693                             PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2694                                 newpte &= ~PT_SOFTWARE;
2695 
2696                         if (!(attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2697                                 newpte |= mmu.pt_nx;
2698                 }
2699 
2700                 if (what == HAT_CLR_ATTR) {
2701                         if ((attr & PROT_WRITE) && PTE_GET(oldpte, PT_WRITABLE))
2702                                 newpte &= ~PT_WRITABLE;
2703 
2704                         if ((attr & HAT_NOSYNC) &&
2705                             PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2706                                 newpte &= ~PT_SOFTWARE;
2707 
2708                         if ((attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2709                                 newpte |= mmu.pt_nx;
2710                 }
2711 
2712                 /*
2713                  * Ensure NOSYNC/NOCONSIST mappings have REF and MOD set.
2714                  * x86pte_set() depends on this.
2715                  */
2716                 if (PTE_GET(newpte, PT_SOFTWARE) >= PT_NOSYNC)
2717                         newpte |= PT_REF | PT_MOD;
2718 
2719                 /*
2720                  * what about PROT_READ or others? this code only handles:
2721                  * EXEC, WRITE, NOSYNC
2722                  */
2723 
2724                 /*
2725                  * If new PTE really changed, update the table.
2726                  */
2727                 if (newpte != oldpte) {
2728                         entry = htable_va2entry(vaddr, ht);
2729                         oldpte = hati_update_pte(ht, entry, oldpte, newpte);
2730                         if (oldpte != 0) {
2731                                 x86_hm_exit(pp);
2732                                 goto try_again;
2733                         }
2734                 }
2735                 x86_hm_exit(pp);
2736         }
2737         if (ht)
2738                 htable_release(ht);
2739         XPV_ALLOW_MIGRATE();
2740 }
2741 
2742 /*
2743  * Various wrappers for hat_updateattr()
2744  */
2745 void
2746 hat_setattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2747 {
2748         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2749         hat_updateattr(hat, addr, len, attr, HAT_SET_ATTR);
2750 }
2751 
2752 void
2753 hat_clrattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2754 {
2755         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2756         hat_updateattr(hat, addr, len, attr, HAT_CLR_ATTR);
2757 }
2758 
2759 void
2760 hat_chgattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2761 {
2762         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2763         hat_updateattr(hat, addr, len, attr, HAT_LOAD_ATTR);
2764 }
2765 
2766 void
2767 hat_chgprot(hat_t *hat, caddr_t addr, size_t len, uint_t vprot)
2768 {
2769         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2770         hat_updateattr(hat, addr, len, vprot & HAT_PROT_MASK, HAT_LOAD_ATTR);
2771 }
2772 
2773 /*
2774  * size_t hat_getpagesize(hat, addr)
2775  *      returns pagesize in bytes for <hat, addr>. returns -1 of there is
2776  *      no mapping. This is an advisory call.
2777  */
2778 ssize_t
2779 hat_getpagesize(hat_t *hat, caddr_t addr)
2780 {
2781         uintptr_t       vaddr = ALIGN2PAGE(addr);
2782         htable_t        *ht;
2783         size_t          pagesize;
2784 
2785         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2786         if (IN_VA_HOLE(vaddr))
2787                 return (-1);
2788         ht = htable_getpage(hat, vaddr, NULL);
2789         if (ht == NULL)
2790                 return (-1);
2791         pagesize = LEVEL_SIZE(ht->ht_level);
2792         htable_release(ht);
2793         return (pagesize);
2794 }
2795 
2796 
2797 
2798 /*
2799  * pfn_t hat_getpfnum(hat, addr)
2800  *      returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
2801  */
2802 pfn_t
2803 hat_getpfnum(hat_t *hat, caddr_t addr)
2804 {
2805         uintptr_t       vaddr = ALIGN2PAGE(addr);
2806         htable_t        *ht;
2807         uint_t          entry;
2808         pfn_t           pfn = PFN_INVALID;
2809 
2810         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2811         if (khat_running == 0)
2812                 return (PFN_INVALID);
2813 
2814         if (IN_VA_HOLE(vaddr))
2815                 return (PFN_INVALID);
2816 
2817         XPV_DISALLOW_MIGRATE();
2818         /*
2819          * A very common use of hat_getpfnum() is from the DDI for kernel pages.
2820          * Use the kmap_ptes (which also covers the 32 bit heap) to speed
2821          * this up.
2822          */
2823         if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2824                 x86pte_t pte;
2825                 pgcnt_t pg_index;
2826 
2827                 pg_index = mmu_btop(vaddr - mmu.kmap_addr);
2828                 pte = GET_PTE(PT_INDEX_PTR(mmu.kmap_ptes, pg_index));
2829                 if (PTE_ISVALID(pte))
2830                         /*LINTED [use of constant 0 causes a lint warning] */
2831                         pfn = PTE2PFN(pte, 0);
2832                 XPV_ALLOW_MIGRATE();
2833                 return (pfn);
2834         }
2835 
2836         ht = htable_getpage(hat, vaddr, &entry);
2837         if (ht == NULL) {
2838                 XPV_ALLOW_MIGRATE();
2839                 return (PFN_INVALID);
2840         }
2841         ASSERT(vaddr >= ht->ht_vaddr);
2842         ASSERT(vaddr <= HTABLE_LAST_PAGE(ht));
2843         pfn = PTE2PFN(x86pte_get(ht, entry), ht->ht_level);
2844         if (ht->ht_level > 0)
2845                 pfn += mmu_btop(vaddr & LEVEL_OFFSET(ht->ht_level));
2846         htable_release(ht);
2847         XPV_ALLOW_MIGRATE();
2848         return (pfn);
2849 }
2850 
2851 /*
2852  * int hat_probe(hat, addr)
2853  *      return 0 if no valid mapping is present.  Faster version
2854  *      of hat_getattr in certain architectures.
2855  */
2856 int
2857 hat_probe(hat_t *hat, caddr_t addr)
2858 {
2859         uintptr_t       vaddr = ALIGN2PAGE(addr);
2860         uint_t          entry;
2861         htable_t        *ht;
2862         pgcnt_t         pg_off;
2863 
2864         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2865         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2866         if (IN_VA_HOLE(vaddr))
2867                 return (0);
2868 
2869         /*
2870          * Most common use of hat_probe is from segmap. We special case it
2871          * for performance.
2872          */
2873         if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2874                 pg_off = mmu_btop(vaddr - mmu.kmap_addr);
2875                 if (mmu.pae_hat)
2876                         return (PTE_ISVALID(mmu.kmap_ptes[pg_off]));
2877                 else
2878                         return (PTE_ISVALID(
2879                             ((x86pte32_t *)mmu.kmap_ptes)[pg_off]));
2880         }
2881 
2882         ht = htable_getpage(hat, vaddr, &entry);
2883         htable_release(ht);
2884         return (ht != NULL);
2885 }
2886 
2887 /*
2888  * Find out if the segment for hat_share()/hat_unshare() is DISM or locked ISM.
2889  */
2890 static int
2891 is_it_dism(hat_t *hat, caddr_t va)
2892 {
2893         struct seg *seg;
2894         struct shm_data *shmd;
2895         struct spt_data *sptd;
2896 
2897         seg = as_findseg(hat->hat_as, va, 0);
2898         ASSERT(seg != NULL);
2899         ASSERT(seg->s_base <= va);
2900         shmd = (struct shm_data *)seg->s_data;
2901         ASSERT(shmd != NULL);
2902         sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2903         ASSERT(sptd != NULL);
2904         if (sptd->spt_flags & SHM_PAGEABLE)
2905                 return (1);
2906         return (0);
2907 }
2908 
2909 /*
2910  * Simple implementation of ISM. hat_share() is similar to hat_memload_array(),
2911  * except that we use the ism_hat's existing mappings to determine the pages
2912  * and protections to use for this hat. If we find a full properly aligned
2913  * and sized pagetable, we will attempt to share the pagetable itself.
2914  */
2915 /*ARGSUSED*/
2916 int
2917 hat_share(
2918         hat_t           *hat,
2919         caddr_t         addr,
2920         hat_t           *ism_hat,
2921         caddr_t         src_addr,
2922         size_t          len,    /* almost useless value, see below.. */
2923         uint_t          ismszc)
2924 {
2925         uintptr_t       vaddr_start = (uintptr_t)addr;
2926         uintptr_t       vaddr;
2927         uintptr_t       eaddr = vaddr_start + len;
2928         uintptr_t       ism_addr_start = (uintptr_t)src_addr;
2929         uintptr_t       ism_addr = ism_addr_start;
2930         uintptr_t       e_ism_addr = ism_addr + len;
2931         htable_t        *ism_ht = NULL;
2932         htable_t        *ht;
2933         x86pte_t        pte;
2934         page_t          *pp;
2935         pfn_t           pfn;
2936         level_t         l;
2937         pgcnt_t         pgcnt;
2938         uint_t          prot;
2939         int             is_dism;
2940         int             flags;
2941 
2942         /*
2943          * We might be asked to share an empty DISM hat by as_dup()
2944          */
2945         ASSERT(hat != kas.a_hat);
2946         ASSERT(eaddr <= _userlimit);
2947         if (!(ism_hat->hat_flags & HAT_SHARED)) {
2948                 ASSERT(hat_get_mapped_size(ism_hat) == 0);
2949                 return (0);
2950         }
2951         XPV_DISALLOW_MIGRATE();
2952 
2953         /*
2954          * The SPT segment driver often passes us a size larger than there are
2955          * valid mappings. That's because it rounds the segment size up to a
2956          * large pagesize, even if the actual memory mapped by ism_hat is less.
2957          */
2958         ASSERT(IS_PAGEALIGNED(vaddr_start));
2959         ASSERT(IS_PAGEALIGNED(ism_addr_start));
2960         ASSERT(ism_hat->hat_flags & HAT_SHARED);
2961         is_dism = is_it_dism(hat, addr);
2962         while (ism_addr < e_ism_addr) {
2963                 /*
2964                  * use htable_walk to get the next valid ISM mapping
2965                  */
2966                 pte = htable_walk(ism_hat, &ism_ht, &ism_addr, e_ism_addr);
2967                 if (ism_ht == NULL)
2968                         break;
2969 
2970                 /*
2971                  * First check to see if we already share the page table.
2972                  */
2973                 l = ism_ht->ht_level;
2974                 vaddr = vaddr_start + (ism_addr - ism_addr_start);
2975                 ht = htable_lookup(hat, vaddr, l);
2976                 if (ht != NULL) {
2977                         if (ht->ht_flags & HTABLE_SHARED_PFN)
2978                                 goto shared;
2979                         htable_release(ht);
2980                         goto not_shared;
2981                 }
2982 
2983                 /*
2984                  * Can't ever share top table.
2985                  */
2986                 if (l == mmu.max_level)
2987                         goto not_shared;
2988 
2989                 /*
2990                  * Avoid level mismatches later due to DISM faults.
2991                  */
2992                 if (is_dism && l > 0)
2993                         goto not_shared;
2994 
2995                 /*
2996                  * addresses and lengths must align
2997                  * table must be fully populated
2998                  * no lower level page tables
2999                  */
3000                 if (ism_addr != ism_ht->ht_vaddr ||
3001                     (vaddr & LEVEL_OFFSET(l + 1)) != 0)
3002                         goto not_shared;
3003 
3004                 /*
3005                  * The range of address space must cover a full table.
3006                  */
3007                 if (e_ism_addr - ism_addr < LEVEL_SIZE(l + 1))
3008                         goto not_shared;
3009 
3010                 /*
3011                  * All entries in the ISM page table must be leaf PTEs.
3012                  */
3013                 if (l > 0) {
3014                         int e;
3015 
3016                         /*
3017                          * We know the 0th is from htable_walk() above.
3018                          */
3019                         for (e = 1; e < HTABLE_NUM_PTES(ism_ht); ++e) {
3020                                 x86pte_t pte;
3021                                 pte = x86pte_get(ism_ht, e);
3022                                 if (!PTE_ISPAGE(pte, l))
3023                                         goto not_shared;
3024                         }
3025                 }
3026 
3027                 /*
3028                  * share the page table
3029                  */
3030                 ht = htable_create(hat, vaddr, l, ism_ht);
3031 shared:
3032                 ASSERT(ht->ht_flags & HTABLE_SHARED_PFN);
3033                 ASSERT(ht->ht_shares == ism_ht);
3034                 hat->hat_ism_pgcnt +=
3035                     (ism_ht->ht_valid_cnt - ht->ht_valid_cnt) <<
3036                     (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3037                 ht->ht_valid_cnt = ism_ht->ht_valid_cnt;
3038                 htable_release(ht);
3039                 ism_addr = ism_ht->ht_vaddr + LEVEL_SIZE(l + 1);
3040                 htable_release(ism_ht);
3041                 ism_ht = NULL;
3042                 continue;
3043 
3044 not_shared:
3045                 /*
3046                  * Unable to share the page table. Instead we will
3047                  * create new mappings from the values in the ISM mappings.
3048                  * Figure out what level size mappings to use;
3049                  */
3050                 for (l = ism_ht->ht_level; l > 0; --l) {
3051                         if (LEVEL_SIZE(l) <= eaddr - vaddr &&
3052                             (vaddr & LEVEL_OFFSET(l)) == 0)
3053                                 break;
3054                 }
3055 
3056                 /*
3057                  * The ISM mapping might be larger than the share area,
3058                  * be careful to truncate it if needed.
3059                  */
3060                 if (eaddr - vaddr >= LEVEL_SIZE(ism_ht->ht_level)) {
3061                         pgcnt = mmu_btop(LEVEL_SIZE(ism_ht->ht_level));
3062                 } else {
3063                         pgcnt = mmu_btop(eaddr - vaddr);
3064                         l = 0;
3065                 }
3066 
3067                 pfn = PTE2PFN(pte, ism_ht->ht_level);
3068                 ASSERT(pfn != PFN_INVALID);
3069                 while (pgcnt > 0) {
3070                         /*
3071                          * Make a new pte for the PFN for this level.
3072                          * Copy protections for the pte from the ISM pte.
3073                          */
3074                         pp = page_numtopp_nolock(pfn);
3075                         ASSERT(pp != NULL);
3076 
3077                         prot = PROT_USER | PROT_READ | HAT_UNORDERED_OK;
3078                         if (PTE_GET(pte, PT_WRITABLE))
3079                                 prot |= PROT_WRITE;
3080                         if (!PTE_GET(pte, PT_NX))
3081                                 prot |= PROT_EXEC;
3082 
3083                         flags = HAT_LOAD;
3084                         if (!is_dism)
3085                                 flags |= HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST;
3086                         while (hati_load_common(hat, vaddr, pp, prot, flags,
3087                             l, pfn) != 0) {
3088                                 if (l == 0)
3089                                         panic("hati_load_common() failure");
3090                                 --l;
3091                         }
3092 
3093                         vaddr += LEVEL_SIZE(l);
3094                         ism_addr += LEVEL_SIZE(l);
3095                         pfn += mmu_btop(LEVEL_SIZE(l));
3096                         pgcnt -= mmu_btop(LEVEL_SIZE(l));
3097                 }
3098         }
3099         if (ism_ht != NULL)
3100                 htable_release(ism_ht);
3101         XPV_ALLOW_MIGRATE();
3102         return (0);
3103 }
3104 
3105 
3106 /*
3107  * hat_unshare() is similar to hat_unload_callback(), but
3108  * we have to look for empty shared pagetables. Note that
3109  * hat_unshare() is always invoked against an entire segment.
3110  */
3111 /*ARGSUSED*/
3112 void
3113 hat_unshare(hat_t *hat, caddr_t addr, size_t len, uint_t ismszc)
3114 {
3115         uint64_t        vaddr = (uintptr_t)addr;
3116         uintptr_t       eaddr = vaddr + len;
3117         htable_t        *ht = NULL;
3118         uint_t          need_demaps = 0;
3119         int             flags = HAT_UNLOAD_UNMAP;
3120         level_t         l;
3121 
3122         ASSERT(hat != kas.a_hat);
3123         ASSERT(eaddr <= _userlimit);
3124         ASSERT(IS_PAGEALIGNED(vaddr));
3125         ASSERT(IS_PAGEALIGNED(eaddr));
3126         XPV_DISALLOW_MIGRATE();
3127 
3128         /*
3129          * First go through and remove any shared pagetables.
3130          *
3131          * Note that it's ok to delay the TLB shootdown till the entire range is
3132          * finished, because if hat_pageunload() were to unload a shared
3133          * pagetable page, its hat_tlb_inval() will do a global TLB invalidate.
3134          */
3135         l = mmu.max_page_level;
3136         if (l == mmu.max_level)
3137                 --l;
3138         for (; l >= 0; --l) {
3139                 for (vaddr = (uintptr_t)addr; vaddr < eaddr;
3140                     vaddr = (vaddr & LEVEL_MASK(l + 1)) + LEVEL_SIZE(l + 1)) {
3141                         ASSERT(!IN_VA_HOLE(vaddr));
3142                         /*
3143                          * find a pagetable that maps the current address
3144                          */
3145                         ht = htable_lookup(hat, vaddr, l);
3146                         if (ht == NULL)
3147                                 continue;
3148                         if (ht->ht_flags & HTABLE_SHARED_PFN) {
3149                                 /*
3150                                  * clear page count, set valid_cnt to 0,
3151                                  * let htable_release() finish the job
3152                                  */
3153                                 hat->hat_ism_pgcnt -= ht->ht_valid_cnt <<
3154                                     (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3155                                 ht->ht_valid_cnt = 0;
3156                                 need_demaps = 1;
3157                         }
3158                         htable_release(ht);
3159                 }
3160         }
3161 
3162         /*
3163          * flush the TLBs - since we're probably dealing with MANY mappings
3164          * we do just one CR3 reload.
3165          */
3166         if (!(hat->hat_flags & HAT_FREEING) && need_demaps)
3167                 hat_tlb_inval(hat, DEMAP_ALL_ADDR);
3168 
3169         /*
3170          * Now go back and clean up any unaligned mappings that
3171          * couldn't share pagetables.
3172          */
3173         if (!is_it_dism(hat, addr))
3174                 flags |= HAT_UNLOAD_UNLOCK;
3175         hat_unload(hat, addr, len, flags);
3176         XPV_ALLOW_MIGRATE();
3177 }
3178 
3179 
3180 /*
3181  * hat_reserve() does nothing
3182  */
3183 /*ARGSUSED*/
3184 void
3185 hat_reserve(struct as *as, caddr_t addr, size_t len)
3186 {
3187 }
3188 
3189 
3190 /*
3191  * Called when all mappings to a page should have write permission removed.
3192  * Mostly stolen from hat_pagesync()
3193  */
3194 static void
3195 hati_page_clrwrt(struct page *pp)
3196 {
3197         hment_t         *hm = NULL;
3198         htable_t        *ht;
3199         uint_t          entry;
3200         x86pte_t        old;
3201         x86pte_t        new;
3202         uint_t          pszc = 0;
3203 
3204         XPV_DISALLOW_MIGRATE();
3205 next_size:
3206         /*
3207          * walk thru the mapping list clearing write permission
3208          */
3209         x86_hm_enter(pp);
3210         while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3211                 if (ht->ht_level < pszc)
3212                         continue;
3213                 old = x86pte_get(ht, entry);
3214 
3215                 for (;;) {
3216                         /*
3217                          * Is this mapping of interest?
3218                          */
3219                         if (PTE2PFN(old, ht->ht_level) != pp->p_pagenum ||
3220                             PTE_GET(old, PT_WRITABLE) == 0)
3221                                 break;
3222 
3223                         /*
3224                          * Clear ref/mod writable bits. This requires cross
3225                          * calls to ensure any executing TLBs see cleared bits.
3226                          */
3227                         new = old;
3228                         PTE_CLR(new, PT_REF | PT_MOD | PT_WRITABLE);
3229                         old = hati_update_pte(ht, entry, old, new);
3230                         if (old != 0)
3231                                 continue;
3232 
3233                         break;
3234                 }
3235         }
3236         x86_hm_exit(pp);
3237         while (pszc < pp->p_szc) {
3238                 page_t *tpp;
3239                 pszc++;
3240                 tpp = PP_GROUPLEADER(pp, pszc);
3241                 if (pp != tpp) {
3242                         pp = tpp;
3243                         goto next_size;
3244                 }
3245         }
3246         XPV_ALLOW_MIGRATE();
3247 }
3248 
3249 /*
3250  * void hat_page_setattr(pp, flag)
3251  * void hat_page_clrattr(pp, flag)
3252  *      used to set/clr ref/mod bits.
3253  */
3254 void
3255 hat_page_setattr(struct page *pp, uint_t flag)
3256 {
3257         vnode_t         *vp = pp->p_vnode;
3258         kmutex_t        *vphm = NULL;
3259         page_t          **listp;
3260         int             noshuffle;
3261 
3262         noshuffle = flag & P_NSH;
3263         flag &= ~P_NSH;
3264 
3265         if (PP_GETRM(pp, flag) == flag)
3266                 return;
3267 
3268         if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp) &&
3269             !noshuffle) {
3270                 vphm = page_vnode_mutex(vp);
3271                 mutex_enter(vphm);
3272         }
3273 
3274         PP_SETRM(pp, flag);
3275 
3276         if (vphm != NULL) {
3277 
3278                 /*
3279                  * Some File Systems examine v_pages for NULL w/o
3280                  * grabbing the vphm mutex. Must not let it become NULL when
3281                  * pp is the only page on the list.
3282                  */
3283                 if (pp->p_vpnext != pp) {
3284                         page_vpsub(&vp->v_pages, pp);
3285                         if (vp->v_pages != NULL)
3286                                 listp = &vp->v_pages->p_vpprev->p_vpnext;
3287                         else
3288                                 listp = &vp->v_pages;
3289                         page_vpadd(listp, pp);
3290                 }
3291                 mutex_exit(vphm);
3292         }
3293 }
3294 
3295 void
3296 hat_page_clrattr(struct page *pp, uint_t flag)
3297 {
3298         vnode_t         *vp = pp->p_vnode;
3299         ASSERT(!(flag & ~(P_MOD | P_REF | P_RO)));
3300 
3301         /*
3302          * Caller is expected to hold page's io lock for VMODSORT to work
3303          * correctly with pvn_vplist_dirty() and pvn_getdirty() when mod
3304          * bit is cleared.
3305          * We don't have assert to avoid tripping some existing third party
3306          * code. The dirty page is moved back to top of the v_page list
3307          * after IO is done in pvn_write_done().
3308          */
3309         PP_CLRRM(pp, flag);
3310 
3311         if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp)) {
3312 
3313                 /*
3314                  * VMODSORT works by removing write permissions and getting
3315                  * a fault when a page is made dirty. At this point
3316                  * we need to remove write permission from all mappings
3317                  * to this page.
3318                  */
3319                 hati_page_clrwrt(pp);
3320         }
3321 }
3322 
3323 /*
3324  *      If flag is specified, returns 0 if attribute is disabled
3325  *      and non zero if enabled.  If flag specifes multiple attributes
3326  *      then returns 0 if ALL attributes are disabled.  This is an advisory
3327  *      call.
3328  */
3329 uint_t
3330 hat_page_getattr(struct page *pp, uint_t flag)
3331 {
3332         return (PP_GETRM(pp, flag));
3333 }
3334 
3335 
3336 /*
3337  * common code used by hat_pageunload() and hment_steal()
3338  */
3339 hment_t *
3340 hati_page_unmap(page_t *pp, htable_t *ht, uint_t entry)
3341 {
3342         x86pte_t old_pte;
3343         pfn_t pfn = pp->p_pagenum;
3344         hment_t *hm;
3345 
3346         /*
3347          * We need to acquire a hold on the htable in order to
3348          * do the invalidate. We know the htable must exist, since
3349          * unmap's don't release the htable until after removing any
3350          * hment. Having x86_hm_enter() keeps that from proceeding.
3351          */
3352         htable_acquire(ht);
3353 
3354         /*
3355          * Invalidate the PTE and remove the hment.
3356          */
3357         old_pte = x86pte_inval(ht, entry, 0, NULL, B_TRUE);
3358         if (PTE2PFN(old_pte, ht->ht_level) != pfn) {
3359                 panic("x86pte_inval() failure found PTE = " FMT_PTE
3360                     " pfn being unmapped is %lx ht=0x%lx entry=0x%x",
3361                     old_pte, pfn, (uintptr_t)ht, entry);
3362         }
3363 
3364         /*
3365          * Clean up all the htable information for this mapping
3366          */
3367         ASSERT(ht->ht_valid_cnt > 0);
3368         HTABLE_DEC(ht->ht_valid_cnt);
3369         PGCNT_DEC(ht->ht_hat, ht->ht_level);
3370 
3371         /*
3372          * sync ref/mod bits to the page_t
3373          */
3374         if (PTE_GET(old_pte, PT_SOFTWARE) < PT_NOSYNC)
3375                 hati_sync_pte_to_page(pp, old_pte, ht->ht_level);
3376 
3377         /*
3378          * Remove the mapping list entry for this page.
3379          */
3380         hm = hment_remove(pp, ht, entry);
3381 
3382         /*
3383          * drop the mapping list lock so that we might free the
3384          * hment and htable.
3385          */
3386         x86_hm_exit(pp);
3387         htable_release(ht);
3388         return (hm);
3389 }
3390 
3391 extern int      vpm_enable;
3392 /*
3393  * Unload all translations to a page. If the page is a subpage of a large
3394  * page, the large page mappings are also removed.
3395  *
3396  * The forceflags are unused.
3397  */
3398 
3399 /*ARGSUSED*/
3400 static int
3401 hati_pageunload(struct page *pp, uint_t pg_szcd, uint_t forceflag)
3402 {
3403         page_t          *cur_pp = pp;
3404         hment_t         *hm;
3405         hment_t         *prev;
3406         htable_t        *ht;
3407         uint_t          entry;
3408         level_t         level;
3409 
3410         XPV_DISALLOW_MIGRATE();
3411 
3412         /*
3413          * prevent recursion due to kmem_free()
3414          */
3415         ++curthread->t_hatdepth;
3416         ASSERT(curthread->t_hatdepth < 16);
3417 
3418 #if defined(__amd64)
3419         /*
3420          * clear the vpm ref.
3421          */
3422         if (vpm_enable) {
3423                 pp->p_vpmref = 0;
3424         }
3425 #endif
3426         /*
3427          * The loop with next_size handles pages with multiple pagesize mappings
3428          */
3429 next_size:
3430         for (;;) {
3431 
3432                 /*
3433                  * Get a mapping list entry
3434                  */
3435                 x86_hm_enter(cur_pp);
3436                 for (prev = NULL; ; prev = hm) {
3437                         hm = hment_walk(cur_pp, &ht, &entry, prev);
3438                         if (hm == NULL) {
3439                                 x86_hm_exit(cur_pp);
3440 
3441                                 /*
3442                                  * If not part of a larger page, we're done.
3443                                  */
3444                                 if (cur_pp->p_szc <= pg_szcd) {
3445                                         ASSERT(curthread->t_hatdepth > 0);
3446                                         --curthread->t_hatdepth;
3447                                         XPV_ALLOW_MIGRATE();
3448                                         return (0);
3449                                 }
3450 
3451                                 /*
3452                                  * Else check the next larger page size.
3453                                  * hat_page_demote() may decrease p_szc
3454                                  * but that's ok we'll just take an extra
3455                                  * trip discover there're no larger mappings
3456                                  * and return.
3457                                  */
3458                                 ++pg_szcd;
3459                                 cur_pp = PP_GROUPLEADER(cur_pp, pg_szcd);
3460                                 goto next_size;
3461                         }
3462 
3463                         /*
3464                          * If this mapping size matches, remove it.
3465                          */
3466                         level = ht->ht_level;
3467                         if (level == pg_szcd)
3468                                 break;
3469                 }
3470 
3471                 /*
3472                  * Remove the mapping list entry for this page.
3473                  * Note this does the x86_hm_exit() for us.
3474                  */
3475                 hm = hati_page_unmap(cur_pp, ht, entry);
3476                 if (hm != NULL)
3477                         hment_free(hm);
3478         }
3479 }
3480 
3481 int
3482 hat_pageunload(struct page *pp, uint_t forceflag)
3483 {
3484         ASSERT(PAGE_EXCL(pp));
3485         return (hati_pageunload(pp, 0, forceflag));
3486 }
3487 
3488 /*
3489  * Unload all large mappings to pp and reduce by 1 p_szc field of every large
3490  * page level that included pp.
3491  *
3492  * pp must be locked EXCL. Even though no other constituent pages are locked
3493  * it's legal to unload large mappings to pp because all constituent pages of
3494  * large locked mappings have to be locked SHARED.  therefore if we have EXCL
3495  * lock on one of constituent pages none of the large mappings to pp are
3496  * locked.
3497  *
3498  * Change (always decrease) p_szc field starting from the last constituent
3499  * page and ending with root constituent page so that root's pszc always shows
3500  * the area where hat_page_demote() may be active.
3501  *
3502  * This mechanism is only used for file system pages where it's not always
3503  * possible to get EXCL locks on all constituent pages to demote the size code
3504  * (as is done for anonymous or kernel large pages).
3505  */
3506 void
3507 hat_page_demote(page_t *pp)
3508 {
3509         uint_t          pszc;
3510         uint_t          rszc;
3511         uint_t          szc;
3512         page_t          *rootpp;
3513         page_t          *firstpp;
3514         page_t          *lastpp;
3515         pgcnt_t         pgcnt;
3516 
3517         ASSERT(PAGE_EXCL(pp));
3518         ASSERT(!PP_ISFREE(pp));
3519         ASSERT(page_szc_lock_assert(pp));
3520 
3521         if (pp->p_szc == 0)
3522                 return;
3523 
3524         rootpp = PP_GROUPLEADER(pp, 1);
3525         (void) hati_pageunload(rootpp, 1, HAT_FORCE_PGUNLOAD);
3526 
3527         /*
3528          * all large mappings to pp are gone
3529          * and no new can be setup since pp is locked exclusively.
3530          *
3531          * Lock the root to make sure there's only one hat_page_demote()
3532          * outstanding within the area of this root's pszc.
3533          *
3534          * Second potential hat_page_demote() is already eliminated by upper
3535          * VM layer via page_szc_lock() but we don't rely on it and use our
3536          * own locking (so that upper layer locking can be changed without
3537          * assumptions that hat depends on upper layer VM to prevent multiple
3538          * hat_page_demote() to be issued simultaneously to the same large
3539          * page).
3540          */
3541 again:
3542         pszc = pp->p_szc;
3543         if (pszc == 0)
3544                 return;
3545         rootpp = PP_GROUPLEADER(pp, pszc);
3546         x86_hm_enter(rootpp);
3547         /*
3548          * If root's p_szc is different from pszc we raced with another
3549          * hat_page_demote().  Drop the lock and try to find the root again.
3550          * If root's p_szc is greater than pszc previous hat_page_demote() is
3551          * not done yet.  Take and release mlist lock of root's root to wait
3552          * for previous hat_page_demote() to complete.
3553          */
3554         if ((rszc = rootpp->p_szc) != pszc) {
3555                 x86_hm_exit(rootpp);
3556                 if (rszc > pszc) {
3557                         /* p_szc of a locked non free page can't increase */
3558                         ASSERT(pp != rootpp);
3559 
3560                         rootpp = PP_GROUPLEADER(rootpp, rszc);
3561                         x86_hm_enter(rootpp);
3562                         x86_hm_exit(rootpp);
3563                 }
3564                 goto again;
3565         }
3566         ASSERT(pp->p_szc == pszc);
3567 
3568         /*
3569          * Decrement by 1 p_szc of every constituent page of a region that
3570          * covered pp. For example if original szc is 3 it gets changed to 2
3571          * everywhere except in region 2 that covered pp. Region 2 that
3572          * covered pp gets demoted to 1 everywhere except in region 1 that
3573          * covered pp. The region 1 that covered pp is demoted to region
3574          * 0. It's done this way because from region 3 we removed level 3
3575          * mappings, from region 2 that covered pp we removed level 2 mappings
3576          * and from region 1 that covered pp we removed level 1 mappings.  All
3577          * changes are done from from high pfn's to low pfn's so that roots
3578          * are changed last allowing one to know the largest region where
3579          * hat_page_demote() is stil active by only looking at the root page.
3580          *
3581          * This algorithm is implemented in 2 while loops. First loop changes
3582          * p_szc of pages to the right of pp's level 1 region and second
3583          * loop changes p_szc of pages of level 1 region that covers pp
3584          * and all pages to the left of level 1 region that covers pp.
3585          * In the first loop p_szc keeps dropping with every iteration
3586          * and in the second loop it keeps increasing with every iteration.
3587          *
3588          * First loop description: Demote pages to the right of pp outside of
3589          * level 1 region that covers pp.  In every iteration of the while
3590          * loop below find the last page of szc region and the first page of
3591          * (szc - 1) region that is immediately to the right of (szc - 1)
3592          * region that covers pp.  From last such page to first such page
3593          * change every page's szc to szc - 1. Decrement szc and continue
3594          * looping until szc is 1. If pp belongs to the last (szc - 1) region
3595          * of szc region skip to the next iteration.
3596          */
3597         szc = pszc;
3598         while (szc > 1) {
3599                 lastpp = PP_GROUPLEADER(pp, szc);
3600                 pgcnt = page_get_pagecnt(szc);
3601                 lastpp += pgcnt - 1;
3602                 firstpp = PP_GROUPLEADER(pp, (szc - 1));
3603                 pgcnt = page_get_pagecnt(szc - 1);
3604                 if (lastpp - firstpp < pgcnt) {
3605                         szc--;
3606                         continue;
3607                 }
3608                 firstpp += pgcnt;
3609                 while (lastpp != firstpp) {
3610                         ASSERT(lastpp->p_szc == pszc);
3611                         lastpp->p_szc = szc - 1;
3612                         lastpp--;
3613                 }
3614                 firstpp->p_szc = szc - 1;
3615                 szc--;
3616         }
3617 
3618         /*
3619          * Second loop description:
3620          * First iteration changes p_szc to 0 of every
3621          * page of level 1 region that covers pp.
3622          * Subsequent iterations find last page of szc region
3623          * immediately to the left of szc region that covered pp
3624          * and first page of (szc + 1) region that covers pp.
3625          * From last to first page change p_szc of every page to szc.
3626          * Increment szc and continue looping until szc is pszc.
3627          * If pp belongs to the fist szc region of (szc + 1) region
3628          * skip to the next iteration.
3629          *
3630          */
3631         szc = 0;
3632         while (szc < pszc) {
3633                 firstpp = PP_GROUPLEADER(pp, (szc + 1));
3634                 if (szc == 0) {
3635                         pgcnt = page_get_pagecnt(1);
3636                         lastpp = firstpp + (pgcnt - 1);
3637                 } else {
3638                         lastpp = PP_GROUPLEADER(pp, szc);
3639                         if (firstpp == lastpp) {
3640                                 szc++;
3641                                 continue;
3642                         }
3643                         lastpp--;
3644                         pgcnt = page_get_pagecnt(szc);
3645                 }
3646                 while (lastpp != firstpp) {
3647                         ASSERT(lastpp->p_szc == pszc);
3648                         lastpp->p_szc = szc;
3649                         lastpp--;
3650                 }
3651                 firstpp->p_szc = szc;
3652                 if (firstpp == rootpp)
3653                         break;
3654                 szc++;
3655         }
3656         x86_hm_exit(rootpp);
3657 }
3658 
3659 /*
3660  * get hw stats from hardware into page struct and reset hw stats
3661  * returns attributes of page
3662  * Flags for hat_pagesync, hat_getstat, hat_sync
3663  *
3664  * define       HAT_SYNC_ZERORM         0x01
3665  *
3666  * Additional flags for hat_pagesync
3667  *
3668  * define       HAT_SYNC_STOPON_REF     0x02
3669  * define       HAT_SYNC_STOPON_MOD     0x04
3670  * define       HAT_SYNC_STOPON_RM      0x06
3671  * define       HAT_SYNC_STOPON_SHARED  0x08
3672  */
3673 uint_t
3674 hat_pagesync(struct page *pp, uint_t flags)
3675 {
3676         hment_t         *hm = NULL;
3677         htable_t        *ht;
3678         uint_t          entry;
3679         x86pte_t        old, save_old;
3680         x86pte_t        new;
3681         uchar_t         nrmbits = P_REF|P_MOD|P_RO;
3682         extern ulong_t  po_share;
3683         page_t          *save_pp = pp;
3684         uint_t          pszc = 0;
3685 
3686         ASSERT(PAGE_LOCKED(pp) || panicstr);
3687 
3688         if (PP_ISRO(pp) && (flags & HAT_SYNC_STOPON_MOD))
3689                 return (pp->p_nrm & nrmbits);
3690 
3691         if ((flags & HAT_SYNC_ZERORM) == 0) {
3692 
3693                 if ((flags & HAT_SYNC_STOPON_REF) != 0 && PP_ISREF(pp))
3694                         return (pp->p_nrm & nrmbits);
3695 
3696                 if ((flags & HAT_SYNC_STOPON_MOD) != 0 && PP_ISMOD(pp))
3697                         return (pp->p_nrm & nrmbits);
3698 
3699                 if ((flags & HAT_SYNC_STOPON_SHARED) != 0 &&
3700                     hat_page_getshare(pp) > po_share) {
3701                         if (PP_ISRO(pp))
3702                                 PP_SETREF(pp);
3703                         return (pp->p_nrm & nrmbits);
3704                 }
3705         }
3706 
3707         XPV_DISALLOW_MIGRATE();
3708 next_size:
3709         /*
3710          * walk thru the mapping list syncing (and clearing) ref/mod bits.
3711          */
3712         x86_hm_enter(pp);
3713         while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3714                 if (ht->ht_level < pszc)
3715                         continue;
3716                 old = x86pte_get(ht, entry);
3717 try_again:
3718 
3719                 ASSERT(PTE2PFN(old, ht->ht_level) == pp->p_pagenum);
3720 
3721                 if (PTE_GET(old, PT_REF | PT_MOD) == 0)
3722                         continue;
3723 
3724                 save_old = old;
3725                 if ((flags & HAT_SYNC_ZERORM) != 0) {
3726 
3727                         /*
3728                          * Need to clear ref or mod bits. Need to demap
3729                          * to make sure any executing TLBs see cleared bits.
3730                          */
3731                         new = old;
3732                         PTE_CLR(new, PT_REF | PT_MOD);
3733                         old = hati_update_pte(ht, entry, old, new);
3734                         if (old != 0)
3735                                 goto try_again;
3736 
3737                         old = save_old;
3738                 }
3739 
3740                 /*
3741                  * Sync the PTE
3742                  */
3743                 if (!(flags & HAT_SYNC_ZERORM) &&
3744                     PTE_GET(old, PT_SOFTWARE) <= PT_NOSYNC)
3745                         hati_sync_pte_to_page(pp, old, ht->ht_level);
3746 
3747                 /*
3748                  * can stop short if we found a ref'd or mod'd page
3749                  */
3750                 if ((flags & HAT_SYNC_STOPON_MOD) && PP_ISMOD(save_pp) ||
3751                     (flags & HAT_SYNC_STOPON_REF) && PP_ISREF(save_pp)) {
3752                         x86_hm_exit(pp);
3753                         goto done;
3754                 }
3755         }
3756         x86_hm_exit(pp);
3757         while (pszc < pp->p_szc) {
3758                 page_t *tpp;
3759                 pszc++;
3760                 tpp = PP_GROUPLEADER(pp, pszc);
3761                 if (pp != tpp) {
3762                         pp = tpp;
3763                         goto next_size;
3764                 }
3765         }
3766 done:
3767         XPV_ALLOW_MIGRATE();
3768         return (save_pp->p_nrm & nrmbits);
3769 }
3770 
3771 /*
3772  * returns approx number of mappings to this pp.  A return of 0 implies
3773  * there are no mappings to the page.
3774  */
3775 ulong_t
3776 hat_page_getshare(page_t *pp)
3777 {
3778         uint_t cnt;
3779         cnt = hment_mapcnt(pp);
3780 #if defined(__amd64)
3781         if (vpm_enable && pp->p_vpmref) {
3782                 cnt += 1;
3783         }
3784 #endif
3785         return (cnt);
3786 }
3787 
3788 /*
3789  * Return 1 the number of mappings exceeds sh_thresh. Return 0
3790  * otherwise.
3791  */
3792 int
3793 hat_page_checkshare(page_t *pp, ulong_t sh_thresh)
3794 {
3795         return (hat_page_getshare(pp) > sh_thresh);
3796 }
3797 
3798 /*
3799  * hat_softlock isn't supported anymore
3800  */
3801 /*ARGSUSED*/
3802 faultcode_t
3803 hat_softlock(
3804         hat_t *hat,
3805         caddr_t addr,
3806         size_t *len,
3807         struct page **page_array,
3808         uint_t flags)
3809 {
3810         return (FC_NOSUPPORT);
3811 }
3812 
3813 
3814 
3815 /*
3816  * Routine to expose supported HAT features to platform independent code.
3817  */
3818 /*ARGSUSED*/
3819 int
3820 hat_supported(enum hat_features feature, void *arg)
3821 {
3822         switch (feature) {
3823 
3824         case HAT_SHARED_PT:     /* this is really ISM */
3825                 return (1);
3826 
3827         case HAT_DYNAMIC_ISM_UNMAP:
3828                 return (0);
3829 
3830         case HAT_VMODSORT:
3831                 return (1);
3832 
3833         case HAT_SHARED_REGIONS:
3834                 return (0);
3835 
3836         default:
3837                 panic("hat_supported() - unknown feature");
3838         }
3839         return (0);
3840 }
3841 
3842 /*
3843  * Called when a thread is exiting and has been switched to the kernel AS
3844  */
3845 void
3846 hat_thread_exit(kthread_t *thd)
3847 {
3848         ASSERT(thd->t_procp->p_as == &kas);
3849         XPV_DISALLOW_MIGRATE();
3850         hat_switch(thd->t_procp->p_as->a_hat);
3851         XPV_ALLOW_MIGRATE();
3852 }
3853 
3854 /*
3855  * Setup the given brand new hat structure as the new HAT on this cpu's mmu.
3856  */
3857 /*ARGSUSED*/
3858 void
3859 hat_setup(hat_t *hat, int flags)
3860 {
3861         XPV_DISALLOW_MIGRATE();
3862         kpreempt_disable();
3863 
3864         hat_switch(hat);
3865 
3866         kpreempt_enable();
3867         XPV_ALLOW_MIGRATE();
3868 }
3869 
3870 /*
3871  * Prepare for a CPU private mapping for the given address.
3872  *
3873  * The address can only be used from a single CPU and can be remapped
3874  * using hat_mempte_remap().  Return the address of the PTE.
3875  *
3876  * We do the htable_create() if necessary and increment the valid count so
3877  * the htable can't disappear.  We also hat_devload() the page table into
3878  * kernel so that the PTE is quickly accessed.
3879  */
3880 hat_mempte_t
3881 hat_mempte_setup(caddr_t addr)
3882 {
3883         uintptr_t       va = (uintptr_t)addr;
3884         htable_t        *ht;
3885         uint_t          entry;
3886         x86pte_t        oldpte;
3887         hat_mempte_t    p;
3888 
3889         ASSERT(IS_PAGEALIGNED(va));
3890         ASSERT(!IN_VA_HOLE(va));
3891         ++curthread->t_hatdepth;
3892         XPV_DISALLOW_MIGRATE();
3893         ht = htable_getpte(kas.a_hat, va, &entry, &oldpte, 0);
3894         if (ht == NULL) {
3895                 ht = htable_create(kas.a_hat, va, 0, NULL);
3896                 entry = htable_va2entry(va, ht);
3897                 ASSERT(ht->ht_level == 0);
3898                 oldpte = x86pte_get(ht, entry);
3899         }
3900         if (PTE_ISVALID(oldpte))
3901                 panic("hat_mempte_setup(): address already mapped"
3902                     "ht=%p, entry=%d, pte=" FMT_PTE, (void *)ht, entry, oldpte);
3903 
3904         /*
3905          * increment ht_valid_cnt so that the pagetable can't disappear
3906          */
3907         HTABLE_INC(ht->ht_valid_cnt);
3908 
3909         /*
3910          * return the PTE physical address to the caller.
3911          */
3912         htable_release(ht);
3913         XPV_ALLOW_MIGRATE();
3914         p = PT_INDEX_PHYSADDR(pfn_to_pa(ht->ht_pfn), entry);
3915         --curthread->t_hatdepth;
3916         return (p);
3917 }
3918 
3919 /*
3920  * Release a CPU private mapping for the given address.
3921  * We decrement the htable valid count so it might be destroyed.
3922  */
3923 /*ARGSUSED1*/
3924 void
3925 hat_mempte_release(caddr_t addr, hat_mempte_t pte_pa)
3926 {
3927         htable_t        *ht;
3928 
3929         XPV_DISALLOW_MIGRATE();
3930         /*
3931          * invalidate any left over mapping and decrement the htable valid count
3932          */
3933 #ifdef __xpv
3934         if (HYPERVISOR_update_va_mapping((uintptr_t)addr, 0,
3935             UVMF_INVLPG | UVMF_LOCAL))
3936                 panic("HYPERVISOR_update_va_mapping() failed");
3937 #else
3938         {
3939                 x86pte_t *pteptr;
3940 
3941                 pteptr = x86pte_mapin(mmu_btop(pte_pa),
3942                     (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
3943                 if (mmu.pae_hat)
3944                         *pteptr = 0;
3945                 else
3946                         *(x86pte32_t *)pteptr = 0;
3947                 mmu_tlbflush_entry(addr);
3948                 x86pte_mapout();
3949         }
3950 #endif
3951 
3952         ht = htable_getpte(kas.a_hat, ALIGN2PAGE(addr), NULL, NULL, 0);
3953         if (ht == NULL)
3954                 panic("hat_mempte_release(): invalid address");
3955         ASSERT(ht->ht_level == 0);
3956         HTABLE_DEC(ht->ht_valid_cnt);
3957         htable_release(ht);
3958         XPV_ALLOW_MIGRATE();
3959 }
3960 
3961 /*
3962  * Apply a temporary CPU private mapping to a page. We flush the TLB only
3963  * on this CPU, so this ought to have been called with preemption disabled.
3964  */
3965 void
3966 hat_mempte_remap(
3967         pfn_t           pfn,
3968         caddr_t         addr,
3969         hat_mempte_t    pte_pa,
3970         uint_t          attr,
3971         uint_t          flags)
3972 {
3973         uintptr_t       va = (uintptr_t)addr;
3974         x86pte_t        pte;
3975 
3976         /*
3977          * Remap the given PTE to the new page's PFN. Invalidate only
3978          * on this CPU.
3979          */
3980 #ifdef DEBUG
3981         htable_t        *ht;
3982         uint_t          entry;
3983 
3984         ASSERT(IS_PAGEALIGNED(va));
3985         ASSERT(!IN_VA_HOLE(va));
3986         ht = htable_getpte(kas.a_hat, va, &entry, NULL, 0);
3987         ASSERT(ht != NULL);
3988         ASSERT(ht->ht_level == 0);
3989         ASSERT(ht->ht_valid_cnt > 0);
3990         ASSERT(ht->ht_pfn == mmu_btop(pte_pa));
3991         htable_release(ht);
3992 #endif
3993         XPV_DISALLOW_MIGRATE();
3994         pte = hati_mkpte(pfn, attr, 0, flags);
3995 #ifdef __xpv
3996         if (HYPERVISOR_update_va_mapping(va, pte, UVMF_INVLPG | UVMF_LOCAL))
3997                 panic("HYPERVISOR_update_va_mapping() failed");
3998 #else
3999         {
4000                 x86pte_t *pteptr;
4001 
4002                 pteptr = x86pte_mapin(mmu_btop(pte_pa),
4003                     (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
4004                 if (mmu.pae_hat)
4005                         *(x86pte_t *)pteptr = pte;
4006                 else
4007                         *(x86pte32_t *)pteptr = (x86pte32_t)pte;
4008                 mmu_tlbflush_entry(addr);
4009                 x86pte_mapout();
4010         }
4011 #endif
4012         XPV_ALLOW_MIGRATE();
4013 }
4014 
4015 
4016 
4017 /*
4018  * Hat locking functions
4019  * XXX - these two functions are currently being used by hatstats
4020  *      they can be removed by using a per-as mutex for hatstats.
4021  */
4022 void
4023 hat_enter(hat_t *hat)
4024 {
4025         mutex_enter(&hat->hat_mutex);
4026 }
4027 
4028 void
4029 hat_exit(hat_t *hat)
4030 {
4031         mutex_exit(&hat->hat_mutex);
4032 }
4033 
4034 /*
4035  * HAT part of cpu initialization.
4036  */
4037 void
4038 hat_cpu_online(struct cpu *cpup)
4039 {
4040         if (cpup != CPU) {
4041                 x86pte_cpu_init(cpup);
4042                 hat_vlp_setup(cpup);
4043         }
4044         CPUSET_ATOMIC_ADD(khat_cpuset, cpup->cpu_id);
4045 }
4046 
4047 /*
4048  * HAT part of cpu deletion.
4049  * (currently, we only call this after the cpu is safely passivated.)
4050  */
4051 void
4052 hat_cpu_offline(struct cpu *cpup)
4053 {
4054         ASSERT(cpup != CPU);
4055 
4056         CPUSET_ATOMIC_DEL(khat_cpuset, cpup->cpu_id);
4057         hat_vlp_teardown(cpup);
4058         x86pte_cpu_fini(cpup);
4059 }
4060 
4061 /*
4062  * Function called after all CPUs are brought online.
4063  * Used to remove low address boot mappings.
4064  */
4065 void
4066 clear_boot_mappings(uintptr_t low, uintptr_t high)
4067 {
4068         uintptr_t vaddr = low;
4069         htable_t *ht = NULL;
4070         level_t level;
4071         uint_t entry;
4072         x86pte_t pte;
4073 
4074         /*
4075          * On 1st CPU we can unload the prom mappings, basically we blow away
4076          * all virtual mappings under _userlimit.
4077          */
4078         while (vaddr < high) {
4079                 pte = htable_walk(kas.a_hat, &ht, &vaddr, high);
4080                 if (ht == NULL)
4081                         break;
4082 
4083                 level = ht->ht_level;
4084                 entry = htable_va2entry(vaddr, ht);
4085                 ASSERT(level <= mmu.max_page_level);
4086                 ASSERT(PTE_ISPAGE(pte, level));
4087 
4088                 /*
4089                  * Unload the mapping from the page tables.
4090                  */
4091                 (void) x86pte_inval(ht, entry, 0, NULL, B_TRUE);
4092                 ASSERT(ht->ht_valid_cnt > 0);
4093                 HTABLE_DEC(ht->ht_valid_cnt);
4094                 PGCNT_DEC(ht->ht_hat, ht->ht_level);
4095 
4096                 vaddr += LEVEL_SIZE(ht->ht_level);
4097         }
4098         if (ht)
4099                 htable_release(ht);
4100 }
4101 
4102 /*
4103  * Atomically update a new translation for a single page.  If the
4104  * currently installed PTE doesn't match the value we expect to find,
4105  * it's not updated and we return the PTE we found.
4106  *
4107  * If activating nosync or NOWRITE and the page was modified we need to sync
4108  * with the page_t. Also sync with page_t if clearing ref/mod bits.
4109  */
4110 static x86pte_t
4111 hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected, x86pte_t new)
4112 {
4113         page_t          *pp;
4114         uint_t          rm = 0;
4115         x86pte_t        replaced;
4116 
4117         if (PTE_GET(expected, PT_SOFTWARE) < PT_NOSYNC &&
4118             PTE_GET(expected, PT_MOD | PT_REF) &&
4119             (PTE_GET(new, PT_NOSYNC) || !PTE_GET(new, PT_WRITABLE) ||
4120             !PTE_GET(new, PT_MOD | PT_REF))) {
4121 
4122                 ASSERT(!pfn_is_foreign(PTE2PFN(expected, ht->ht_level)));
4123                 pp = page_numtopp_nolock(PTE2PFN(expected, ht->ht_level));
4124                 ASSERT(pp != NULL);
4125                 if (PTE_GET(expected, PT_MOD))
4126                         rm |= P_MOD;
4127                 if (PTE_GET(expected, PT_REF))
4128                         rm |= P_REF;
4129                 PTE_CLR(new, PT_MOD | PT_REF);
4130         }
4131 
4132         replaced = x86pte_update(ht, entry, expected, new);
4133         if (replaced != expected)
4134                 return (replaced);
4135 
4136         if (rm) {
4137                 /*
4138                  * sync to all constituent pages of a large page
4139                  */
4140                 pgcnt_t pgcnt = page_get_pagecnt(ht->ht_level);
4141                 ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
4142                 while (pgcnt-- > 0) {
4143                         /*
4144                          * hat_page_demote() can't decrease
4145                          * pszc below this mapping size
4146                          * since large mapping existed after we
4147                          * took mlist lock.
4148                          */
4149                         ASSERT(pp->p_szc >= ht->ht_level);
4150                         hat_page_setattr(pp, rm);
4151                         ++pp;
4152                 }
4153         }
4154 
4155         return (0);
4156 }
4157 
4158 /* ARGSUSED */
4159 void
4160 hat_join_srd(struct hat *hat, vnode_t *evp)
4161 {
4162 }
4163 
4164 /* ARGSUSED */
4165 hat_region_cookie_t
4166 hat_join_region(struct hat *hat,
4167     caddr_t r_saddr,
4168     size_t r_size,
4169     void *r_obj,
4170     u_offset_t r_objoff,
4171     uchar_t r_perm,
4172     uchar_t r_pgszc,
4173     hat_rgn_cb_func_t r_cb_function,
4174     uint_t flags)
4175 {
4176         panic("No shared region support on x86");
4177         return (HAT_INVALID_REGION_COOKIE);
4178 }
4179 
4180 /* ARGSUSED */
4181 void
4182 hat_leave_region(struct hat *hat, hat_region_cookie_t rcookie, uint_t flags)
4183 {
4184         panic("No shared region support on x86");
4185 }
4186 
4187 /* ARGSUSED */
4188 void
4189 hat_dup_region(struct hat *hat, hat_region_cookie_t rcookie)
4190 {
4191         panic("No shared region support on x86");
4192 }
4193 
4194 
4195 /*
4196  * Kernel Physical Mapping (kpm) facility
4197  *
4198  * Most of the routines needed to support segkpm are almost no-ops on the
4199  * x86 platform.  We map in the entire segment when it is created and leave
4200  * it mapped in, so there is no additional work required to set up and tear
4201  * down individual mappings.  All of these routines were created to support
4202  * SPARC platforms that have to avoid aliasing in their virtually indexed
4203  * caches.
4204  *
4205  * Most of the routines have sanity checks in them (e.g. verifying that the
4206  * passed-in page is locked).  We don't actually care about most of these
4207  * checks on x86, but we leave them in place to identify problems in the
4208  * upper levels.
4209  */
4210 
4211 /*
4212  * Map in a locked page and return the vaddr.
4213  */
4214 /*ARGSUSED*/
4215 caddr_t
4216 hat_kpm_mapin(struct page *pp, struct kpme *kpme)
4217 {
4218         caddr_t         vaddr;
4219 
4220 #ifdef DEBUG
4221         if (kpm_enable == 0) {
4222                 cmn_err(CE_WARN, "hat_kpm_mapin: kpm_enable not set\n");
4223                 return ((caddr_t)NULL);
4224         }
4225 
4226         if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4227                 cmn_err(CE_WARN, "hat_kpm_mapin: pp zero or not locked\n");
4228                 return ((caddr_t)NULL);
4229         }
4230 #endif
4231 
4232         vaddr = hat_kpm_page2va(pp, 1);
4233 
4234         return (vaddr);
4235 }
4236 
4237 /*
4238  * Mapout a locked page.
4239  */
4240 /*ARGSUSED*/
4241 void
4242 hat_kpm_mapout(struct page *pp, struct kpme *kpme, caddr_t vaddr)
4243 {
4244 #ifdef DEBUG
4245         if (kpm_enable == 0) {
4246                 cmn_err(CE_WARN, "hat_kpm_mapout: kpm_enable not set\n");
4247                 return;
4248         }
4249 
4250         if (IS_KPM_ADDR(vaddr) == 0) {
4251                 cmn_err(CE_WARN, "hat_kpm_mapout: no kpm address\n");
4252                 return;
4253         }
4254 
4255         if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4256                 cmn_err(CE_WARN, "hat_kpm_mapout: page zero or not locked\n");
4257                 return;
4258         }
4259 #endif
4260 }
4261 
4262 /*
4263  * hat_kpm_mapin_pfn is used to obtain a kpm mapping for physical
4264  * memory addresses that are not described by a page_t.  It can
4265  * also be used for normal pages that are not locked, but beware
4266  * this is dangerous - no locking is performed, so the identity of
4267  * the page could change.  hat_kpm_mapin_pfn is not supported when
4268  * vac_colors > 1, because the chosen va depends on the page identity,
4269  * which could change.
4270  * The caller must only pass pfn's for valid physical addresses; violation
4271  * of this rule will cause panic.
4272  */
4273 caddr_t
4274 hat_kpm_mapin_pfn(pfn_t pfn)
4275 {
4276         caddr_t paddr, vaddr;
4277 
4278         if (kpm_enable == 0)
4279                 return ((caddr_t)NULL);
4280 
4281         paddr = (caddr_t)ptob(pfn);
4282         vaddr = (uintptr_t)kpm_vbase + paddr;
4283 
4284         return ((caddr_t)vaddr);
4285 }
4286 
4287 /*ARGSUSED*/
4288 void
4289 hat_kpm_mapout_pfn(pfn_t pfn)
4290 {
4291         /* empty */
4292 }
4293 
4294 /*
4295  * Return the kpm virtual address for a specific pfn
4296  */
4297 caddr_t
4298 hat_kpm_pfn2va(pfn_t pfn)
4299 {
4300         uintptr_t vaddr = (uintptr_t)kpm_vbase + mmu_ptob(pfn);
4301 
4302         ASSERT(!pfn_is_foreign(pfn));
4303         return ((caddr_t)vaddr);
4304 }
4305 
4306 /*
4307  * Return the kpm virtual address for the page at pp.
4308  */
4309 /*ARGSUSED*/
4310 caddr_t
4311 hat_kpm_page2va(struct page *pp, int checkswap)
4312 {
4313         return (hat_kpm_pfn2va(pp->p_pagenum));
4314 }
4315 
4316 /*
4317  * Return the page frame number for the kpm virtual address vaddr.
4318  */
4319 pfn_t
4320 hat_kpm_va2pfn(caddr_t vaddr)
4321 {
4322         pfn_t           pfn;
4323 
4324         ASSERT(IS_KPM_ADDR(vaddr));
4325 
4326         pfn = (pfn_t)btop(vaddr - kpm_vbase);
4327 
4328         return (pfn);
4329 }
4330 
4331 
4332 /*
4333  * Return the page for the kpm virtual address vaddr.
4334  */
4335 page_t *
4336 hat_kpm_vaddr2page(caddr_t vaddr)
4337 {
4338         pfn_t           pfn;
4339 
4340         ASSERT(IS_KPM_ADDR(vaddr));
4341 
4342         pfn = hat_kpm_va2pfn(vaddr);
4343 
4344         return (page_numtopp_nolock(pfn));
4345 }
4346 
4347 /*
4348  * hat_kpm_fault is called from segkpm_fault when we take a page fault on a
4349  * KPM page.  This should never happen on x86
4350  */
4351 int
4352 hat_kpm_fault(hat_t *hat, caddr_t vaddr)
4353 {
4354         panic("pagefault in seg_kpm.  hat: 0x%p  vaddr: 0x%p",
4355             (void *)hat, (void *)vaddr);
4356 
4357         return (0);
4358 }
4359 
4360 /*ARGSUSED*/
4361 void
4362 hat_kpm_mseghash_clear(int nentries)
4363 {}
4364 
4365 /*ARGSUSED*/
4366 void
4367 hat_kpm_mseghash_update(pgcnt_t inx, struct memseg *msp)
4368 {}
4369 
4370 #ifndef __xpv
4371 void
4372 hat_kpm_addmem_mseg_update(struct memseg *msp, pgcnt_t nkpmpgs,
4373         offset_t kpm_pages_off)
4374 {
4375         _NOTE(ARGUNUSED(nkpmpgs, kpm_pages_off));
4376         pfn_t base, end;
4377 
4378         /*
4379          * kphysm_add_memory_dynamic() does not set nkpmpgs
4380          * when page_t memory is externally allocated.  That
4381          * code must properly calculate nkpmpgs in all cases
4382          * if nkpmpgs needs to be used at some point.
4383          */
4384 
4385         /*
4386          * The meta (page_t) pages for dynamically added memory are allocated
4387          * either from the incoming memory itself or from existing memory.
4388          * In the former case the base of the incoming pages will be different
4389          * than the base of the dynamic segment so call memseg_get_start() to
4390          * get the actual base of the incoming memory for each case.
4391          */
4392 
4393         base = memseg_get_start(msp);
4394         end = msp->pages_end;
4395 
4396         hat_devload(kas.a_hat, kpm_vbase + mmu_ptob(base),
4397             mmu_ptob(end - base), base, PROT_READ | PROT_WRITE,
4398             HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST);
4399 }
4400 
4401 void
4402 hat_kpm_addmem_mseg_insert(struct memseg *msp)
4403 {
4404         _NOTE(ARGUNUSED(msp));
4405 }
4406 
4407 void
4408 hat_kpm_addmem_memsegs_update(struct memseg *msp)
4409 {
4410         _NOTE(ARGUNUSED(msp));
4411 }
4412 
4413 /*
4414  * Return end of metadata for an already setup memseg.
4415  * X86 platforms don't need per-page meta data to support kpm.
4416  */
4417 caddr_t
4418 hat_kpm_mseg_reuse(struct memseg *msp)
4419 {
4420         return ((caddr_t)msp->epages);
4421 }
4422 
4423 void
4424 hat_kpm_delmem_mseg_update(struct memseg *msp, struct memseg **mspp)
4425 {
4426         _NOTE(ARGUNUSED(msp, mspp));
4427         ASSERT(0);
4428 }
4429 
4430 void
4431 hat_kpm_split_mseg_update(struct memseg *msp, struct memseg **mspp,
4432         struct memseg *lo, struct memseg *mid, struct memseg *hi)
4433 {
4434         _NOTE(ARGUNUSED(msp, mspp, lo, mid, hi));
4435         ASSERT(0);
4436 }
4437 
4438 /*
4439  * Walk the memsegs chain, applying func to each memseg span.
4440  */
4441 void
4442 hat_kpm_walk(void (*func)(void *, void *, size_t), void *arg)
4443 {
4444         pfn_t   pbase, pend;
4445         void    *base;
4446         size_t  size;
4447         struct memseg *msp;
4448 
4449         for (msp = memsegs; msp; msp = msp->next) {
4450                 pbase = msp->pages_base;
4451                 pend = msp->pages_end;
4452                 base = ptob(pbase) + kpm_vbase;
4453                 size = ptob(pend - pbase);
4454                 func(arg, base, size);
4455         }
4456 }
4457 
4458 #else   /* __xpv */
4459 
4460 /*
4461  * There are specific Hypervisor calls to establish and remove mappings
4462  * to grant table references and the privcmd driver. We have to ensure
4463  * that a page table actually exists.
4464  */
4465 void
4466 hat_prepare_mapping(hat_t *hat, caddr_t addr, uint64_t *pte_ma)
4467 {
4468         maddr_t base_ma;
4469         htable_t *ht;
4470         uint_t entry;
4471 
4472         ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4473         XPV_DISALLOW_MIGRATE();
4474         ht = htable_create(hat, (uintptr_t)addr, 0, NULL);
4475 
4476         /*
4477          * if an address for pte_ma is passed in, return the MA of the pte
4478          * for this specific address.  This address is only valid as long
4479          * as the htable stays locked.
4480          */
4481         if (pte_ma != NULL) {
4482                 entry = htable_va2entry((uintptr_t)addr, ht);
4483                 base_ma = pa_to_ma(ptob(ht->ht_pfn));
4484                 *pte_ma = base_ma + (entry << mmu.pte_size_shift);
4485         }
4486         XPV_ALLOW_MIGRATE();
4487 }
4488 
4489 void
4490 hat_release_mapping(hat_t *hat, caddr_t addr)
4491 {
4492         htable_t *ht;
4493 
4494         ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4495         XPV_DISALLOW_MIGRATE();
4496         ht = htable_lookup(hat, (uintptr_t)addr, 0);
4497         ASSERT(ht != NULL);
4498         ASSERT(ht->ht_busy >= 2);
4499         htable_release(ht);
4500         htable_release(ht);
4501         XPV_ALLOW_MIGRATE();
4502 }
4503 #endif  /* __xpv */