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 /*
  23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 
  27 #include <sys/param.h>
  28 #include <sys/errno.h>
  29 #include <sys/asm_linkage.h>
  30 #include <sys/machthread.h>
  31 #include <sys/asi.h>
  32 #include <sys/privregs.h>
  33 #include <sys/spitregs.h>
  34 
  35 #include "assym.h"
  36 
  37 /*
  38  * fhc_shutdown_asm(u_longlong_t base, int size)
  39  *
  40  * Flush cpu E$ then shutdown.
  41  * This function is special in that it really sets the D-tags to
  42  * a known state.  And this is the behavior we're looking for.
  43  *
  44  * The flush address is known to be a cpu-unique non-existent
  45  * cacheable address.  We write to non-existent memory, using
  46  * the side effect of d-tag invalidation.
  47  *
  48  * Also, note that this function is never run from main memory.
  49  * Rather it is copied to non-cacheable SRAM (hence the ..._end
  50  * label at the bottom of the function).  This implies that the
  51  * function must be position independent code that doesn't reference 
  52  * cacheable real memory.
  53  */
  54 
  55         ENTRY(fhc_shutdown_asm)
  56         ! turn off errors (we'll be writing to non-existent memory)
  57         stxa    %g0, [%g0]ASI_ESTATE_ERR
  58         membar  #Sync                   ! SYNC
  59 
  60         rdpr    %pstate, %o4
  61         andn    %o4, PSTATE_IE | PSTATE_AM, %o3
  62         wrpr    %o3, %g0, %pstate
  63 1:
  64         brlez,pn %o1, 2f                ! if (len <= 0) exit loop
  65           dec   64, %o1                 ! size -= 64
  66         sta     %g0, [%o0]ASI_MEM       ! store (unpopulated) word
  67         ba      1b
  68           inc   64, %o0                 ! addr += 64
  69 2:
  70         membar  #Sync                   ! SYNC
  71         shutdown                        ! SHUTDOWN
  72         /*NOTREACHED*/
  73 
  74         ! if, for some reason, this cpu doesn't shutdown, just sit here
  75 3:
  76         ba      3b
  77           nop                           ! eventually the master will notice
  78         SET_SIZE(fhc_shutdown_asm)
  79 
  80         .global fhc_shutdown_asm_end
  81 fhc_shutdown_asm_end:
  82