OS-1996 mpt_sas: allow physical topology enumeration in libtopo
Reviewed by: Keith Wesolowski <keith.wesolowski@joyent.com>

*** 20,29 ****
--- 20,30 ----
   */
  
  /*
   * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2012 Nexenta Systems, Inc. All rights reserved.
+  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
   */
  
  /*
   * Copyright (c) 2000 to 2010, LSI Corporation.
   * All rights reserved.
*** 67,76 ****
--- 68,78 ----
  #include <sys/scsi/scsi.h>
  #include <sys/pci.h>
  #include <sys/file.h>
  #include <sys/cpuvar.h>
  #include <sys/policy.h>
+ #include <sys/model.h>
  #include <sys/sysevent.h>
  #include <sys/sysevent/eventdefs.h>
  #include <sys/sysevent/dr.h>
  #include <sys/sata/sata_defs.h>
  #include <sys/scsi/generic/sas.h>
*** 11949,11958 ****
--- 11951,12050 ----
          mutex_exit(&mpt->m_mutex);
          return (status);
  }
  
  static int
+ get_disk_info(mptsas_t *mpt, intptr_t data, int mode)
+ {
+         int i = 0;
+         int count = 0;
+         int ret = 0;
+         mptsas_target_t *ptgt;
+         mptsas_disk_info_t *di;
+         STRUCT_DECL(mptsas_get_disk_info, gdi);
+ 
+         STRUCT_INIT(gdi, get_udatamodel());
+ 
+         if (ddi_copyin((void *)data, STRUCT_BUF(gdi), STRUCT_SIZE(gdi),
+             mode) != 0) {
+                 return (EFAULT);
+         }
+ 
+         /* Find out how many targets there are. */
+         mutex_enter(&mpt->m_mutex);
+         ptgt = (mptsas_target_t *)mptsas_hash_traverse(&mpt->m_active->m_tgttbl,
+             MPTSAS_HASH_FIRST);
+         while (ptgt != NULL) {
+                 count++;
+                 ptgt = (mptsas_target_t *)mptsas_hash_traverse(
+                     &mpt->m_active->m_tgttbl, MPTSAS_HASH_NEXT);
+         }
+         mutex_exit(&mpt->m_mutex);
+ 
+         /*
+          * If we haven't been asked to copy out information on each target,
+          * then just return the count.
+          */
+         STRUCT_FSET(gdi, DiskCount, count);
+         if (STRUCT_FGETP(gdi, PtrDiskInfoArray) == NULL)
+                 goto copy_out;
+ 
+         /*
+          * If we haven't been given a large enough buffer to copy out into,
+          * let the caller know.
+          */
+         if (STRUCT_FGET(gdi, DiskInfoArraySize) <
+             count * sizeof (mptsas_disk_info_t)) {
+                 ret = ENOSPC;
+                 goto copy_out;
+         }
+ 
+         di = kmem_zalloc(count * sizeof (mptsas_disk_info_t), KM_SLEEP);
+ 
+         mutex_enter(&mpt->m_mutex);
+         ptgt = (mptsas_target_t *)mptsas_hash_traverse(&mpt->m_active->m_tgttbl,
+             MPTSAS_HASH_FIRST);
+         while (ptgt != NULL) {
+                 if (i >= count) {
+                         /*
+                          * The number of targets changed while we weren't
+                          * looking, so give up.
+                          */
+                         mutex_exit(&mpt->m_mutex);
+                         kmem_free(di, count * sizeof (mptsas_disk_info_t));
+                         return (EAGAIN);
+                 }
+                 di[i].Instance = mpt->m_instance;
+                 di[i].Enclosure = ptgt->m_enclosure;
+                 di[i].Slot = ptgt->m_slot_num;
+                 di[i].SasAddress = ptgt->m_sas_wwn;
+ 
+                 ptgt = (mptsas_target_t *)mptsas_hash_traverse(
+                     &mpt->m_active->m_tgttbl, MPTSAS_HASH_NEXT);
+                 i++;
+         }
+         mutex_exit(&mpt->m_mutex);
+         STRUCT_FSET(gdi, DiskCount, i);
+ 
+         /* Copy out the disk information to the caller. */
+         if (ddi_copyout((void *)di, STRUCT_FGETP(gdi, PtrDiskInfoArray),
+             i * sizeof (mptsas_disk_info_t), mode) != 0) {
+                 ret = EFAULT;
+         }
+ 
+         kmem_free(di, count * sizeof (mptsas_disk_info_t));
+ 
+ copy_out:
+         if (ddi_copyout(STRUCT_BUF(gdi), (void *)data, STRUCT_SIZE(gdi),
+             mode) != 0) {
+                 ret = EFAULT;
+         }
+ 
+         return (ret);
+ }
+ 
+ static int
  mptsas_ioctl(dev_t dev, int cmd, intptr_t data, int mode, cred_t *credp,
      int *rval)
  {
          int                     status = 0;
          mptsas_t                *mpt;
*** 12069,12078 ****
--- 12161,12173 ----
                          ndi_dc_freehdl(dcp);
                  }
                  goto out;
          }
          switch (cmd) {
+                 case MPTIOCTL_GET_DISK_INFO:
+                         status = get_disk_info(mpt, data, mode);
+                         break;
                  case MPTIOCTL_UPDATE_FLASH:
                          if (ddi_copyin((void *)data, &flashdata,
                                  sizeof (struct mptsas_update_flash), mode)) {
                                  status = EFAULT;
                                  break;