hpsa: honor queue depth of physical devices

When using the ioaccel submission methods, requests destined for RAID volumes
are sometimes diverted to physical devices.  The OS has no or limited
knowledge of these physical devices, so it is up to the driver to avoid
pushing the device too hard.  It is better to honor the physical device queue
limit rather than making the device spew zillions of TASK SET FULL responses.

This is so that hpsa based devices support /sys/block/sdNN/device/queue_type
of simple, which lets the SCSI midlayer automatically adjust the queue_depth
based on TASK SET FULL and GOOD status.

Adjust the queue depth for a new device after it is created based on the
maximum queue depths of the physical devices that constitute the
device. This drops the maximum queue depth from .can_queue of 1024 to
something like 174 for single-drive RAID-0, 348 for two-drive RAID-1, etc.
It also adjusts for the ratio of data to parity drives.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 250 insertions, 68 deletions

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index dcacb29..60f5734 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -247,7 +247,7 @@ static void hpsa_drain_accel_commands(struct ctlr_info *h);
 static void hpsa_flush_cache(struct ctlr_info *h);
 static int hpsa_scsi_ioaccel_queue_command(struct ctlr_info *h,
 	struct CommandList *c, u32 ioaccel_handle, u8 *cdb, int cdb_len,
-	u8 *scsi3addr);
+	u8 *scsi3addr, struct hpsa_scsi_dev_t *phys_disk);
 static void hpsa_command_resubmit_worker(struct work_struct *work);
 
 static inline struct ctlr_info *sdev_to_hba(struct scsi_device *sdev)
@@ -965,12 +965,24 @@ static void hpsa_scsi_update_entry(struct ctlr_info *h, int hostno,
 	/* Raid level changed. */
 	h->dev[entry]->raid_level = new_entry->raid_level;
 
-	/* Raid offload parameters changed. */
+	/* Raid offload parameters changed.  Careful about the ordering. */
+	if (new_entry->offload_config && new_entry->offload_enabled) {
+		/*
+		 * if drive is newly offload_enabled, we want to copy the
+		 * raid map data first.  If previously offload_enabled and
+		 * offload_config were set, raid map data had better be
+		 * the same as it was before.  if raid map data is changed
+		 * then it had better be the case that
+		 * h->dev[entry]->offload_enabled is currently 0.
+		 */
+		h->dev[entry]->raid_map = new_entry->raid_map;
+		h->dev[entry]->ioaccel_handle = new_entry->ioaccel_handle;
+		wmb(); /* ensure raid map updated prior to ->offload_enabled */
+	}
 	h->dev[entry]->offload_config = new_entry->offload_config;
-	h->dev[entry]->offload_enabled = new_entry->offload_enabled;
-	h->dev[entry]->ioaccel_handle = new_entry->ioaccel_handle;
 	h->dev[entry]->offload_to_mirror = new_entry->offload_to_mirror;
-	h->dev[entry]->raid_map = new_entry->raid_map;
+	h->dev[entry]->offload_enabled = new_entry->offload_enabled;
+	h->dev[entry]->queue_depth = new_entry->queue_depth;
 
 	dev_info(&h->pdev->dev, "%s device c%db%dt%dl%d updated.\n",
 		scsi_device_type(new_entry->devtype), hostno, new_entry->bus,
@@ -1096,6 +1108,8 @@ static inline int device_updated(struct hpsa_scsi_dev_t *dev1,
 		return 1;
 	if (dev1->offload_enabled != dev2->offload_enabled)
 		return 1;
+	if (dev1->queue_depth != dev2->queue_depth)
+		return 1;
 	return 0;
 }
 
@@ -1241,6 +1255,85 @@ static void hpsa_show_volume_status(struct ctlr_info *h,
 	}
 }
 
+/*
+ * Figure the list of physical drive pointers for a logical drive with
+ * raid offload configured.
+ */
+static void hpsa_figure_phys_disk_ptrs(struct ctlr_info *h,
+				struct hpsa_scsi_dev_t *dev[], int ndevices,
+				struct hpsa_scsi_dev_t *logical_drive)
+{
+	struct raid_map_data *map = &logical_drive->raid_map;
+	struct raid_map_disk_data *dd = &map->data[0];
+	int i, j;
+	int total_disks_per_row = le16_to_cpu(map->data_disks_per_row) +
+				le16_to_cpu(map->metadata_disks_per_row);
+	int nraid_map_entries = le16_to_cpu(map->row_cnt) *
+				le16_to_cpu(map->layout_map_count) *
+				total_disks_per_row;
+	int nphys_disk = le16_to_cpu(map->layout_map_count) *
+				total_disks_per_row;
+	int qdepth;
+
+	if (nraid_map_entries > RAID_MAP_MAX_ENTRIES)
+		nraid_map_entries = RAID_MAP_MAX_ENTRIES;
+
+	qdepth = 0;
+	for (i = 0; i < nraid_map_entries; i++) {
+		logical_drive->phys_disk[i] = NULL;
+		if (!logical_drive->offload_config)
+			continue;
+		for (j = 0; j < ndevices; j++) {
+			if (dev[j]->devtype != TYPE_DISK)
+				continue;
+			if (is_logical_dev_addr_mode(dev[j]->scsi3addr))
+				continue;
+			if (dev[j]->ioaccel_handle != dd[i].ioaccel_handle)
+				continue;
+
+			logical_drive->phys_disk[i] = dev[j];
+			if (i < nphys_disk)
+				qdepth = min(h->nr_cmds, qdepth +
+				    logical_drive->phys_disk[i]->queue_depth);
+			break;
+		}
+
+		/*
+		 * This can happen if a physical drive is removed and
+		 * the logical drive is degraded.  In that case, the RAID
+		 * map data will refer to a physical disk which isn't actually
+		 * present.  And in that case offload_enabled should already
+		 * be 0, but we'll turn it off here just in case
+		 */
+		if (!logical_drive->phys_disk[i]) {
+			logical_drive->offload_enabled = 0;
+			logical_drive->queue_depth = h->nr_cmds;
+		}
+	}
+	if (nraid_map_entries)
+		/*
+		 * This is correct for reads, too high for full stripe writes,
+		 * way too high for partial stripe writes
+		 */
+		logical_drive->queue_depth = qdepth;
+	else
+		logical_drive->queue_depth = h->nr_cmds;
+}
+
+static void hpsa_update_log_drive_phys_drive_ptrs(struct ctlr_info *h,
+				struct hpsa_scsi_dev_t *dev[], int ndevices)
+{
+	int i;
+
+	for (i = 0; i < ndevices; i++) {
+		if (dev[i]->devtype != TYPE_DISK)
+			continue;
+		if (!is_logical_dev_addr_mode(dev[i]->scsi3addr))
+			continue;
+		hpsa_figure_phys_disk_ptrs(h, dev, ndevices, dev[i]);
+	}
+}
+
 static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
 	struct hpsa_scsi_dev_t *sd[], int nsds)
 {
@@ -1425,8 +1518,12 @@ static int hpsa_slave_alloc(struct scsi_device *sdev)
 	spin_lock_irqsave(&h->devlock, flags);
 	sd = lookup_hpsa_scsi_dev(h, sdev_channel(sdev),
 		sdev_id(sdev), sdev->lun);
-	if (sd != NULL)
+	if (sd != NULL) {
 		sdev->hostdata = sd;
+		if (sd->queue_depth)
+			scsi_change_queue_depth(sdev, sd->queue_depth);
+		atomic_set(&sd->ioaccel_cmds_out, 0);
+	}
 	spin_unlock_irqrestore(&h->devlock, flags);
 	return 0;
 }
@@ -1679,6 +1776,9 @@ static void complete_scsi_command(struct CommandList *cp)
 	cmd->result = (DID_OK << 16); 		/* host byte */
 	cmd->result |= (COMMAND_COMPLETE << 8);	/* msg byte */
 
+	if (cp->cmd_type == CMD_IOACCEL2 || cp->cmd_type == CMD_IOACCEL1)
+		atomic_dec(&cp->phys_disk->ioaccel_cmds_out);
+
 	if (cp->cmd_type == CMD_IOACCEL2)
 		return process_ioaccel2_completion(h, cp, cmd, dev);
 
@@ -1686,6 +1786,8 @@ static void complete_scsi_command(struct CommandList *cp)
 
 	scsi_set_resid(cmd, ei->ResidualCnt);
 	if (ei->CommandStatus == 0) {
+		if (cp->cmd_type == CMD_IOACCEL1)
+			atomic_dec(&cp->phys_disk->ioaccel_cmds_out);
 		cmd_free(h, cp);
 		cmd->scsi_done(cmd);
 		return;
@@ -2248,6 +2350,34 @@ static int hpsa_get_raid_map(struct ctlr_info *h,
 	return rc;
 }
 
+static int hpsa_bmic_id_physical_device(struct ctlr_info *h,
+		unsigned char scsi3addr[], u16 bmic_device_index,
+		struct bmic_identify_physical_device *buf, size_t bufsize)
+{
+	int rc = IO_OK;
+	struct CommandList *c;
+	struct ErrorInfo *ei;
+
+	c = cmd_alloc(h);
+	rc = fill_cmd(c, BMIC_IDENTIFY_PHYSICAL_DEVICE, h, buf, bufsize,
+		0, RAID_CTLR_LUNID, TYPE_CMD);
+	if (rc)
+		goto out;
+
+	c->Request.CDB[2] = bmic_device_index & 0xff;
+	c->Request.CDB[9] = (bmic_device_index >> 8) & 0xff;
+
+	hpsa_scsi_do_simple_cmd_with_retry(h, c, PCI_DMA_FROMDEVICE);
+	ei = c->err_info;
+	if (ei->CommandStatus != 0 && ei->CommandStatus != CMD_DATA_UNDERRUN) {
+		hpsa_scsi_interpret_error(h, c);
+		rc = -1;
+	}
+out:
+	cmd_free(h, c);
+	return rc;
+}
+
 static int hpsa_vpd_page_supported(struct ctlr_info *h,
 	unsigned char scsi3addr[], u8 page)
 {
@@ -2348,7 +2478,7 @@ static int hpsa_get_device_id(struct ctlr_info *h, unsigned char *scsi3addr,
 }
 
 static int hpsa_scsi_do_report_luns(struct ctlr_info *h, int logical,
-		struct ReportLUNdata *buf, int bufsize,
+		void *buf, int bufsize,
 		int extended_response)
 {
 	int rc = IO_OK;
@@ -2377,11 +2507,13 @@ static int hpsa_scsi_do_report_luns(struct ctlr_info *h, int logical,
 		hpsa_scsi_interpret_error(h, c);
 		rc = -1;
 	} else {
-		if (buf->extended_response_flag != extended_response) {
+		struct ReportLUNdata *rld = buf;
+
+		if (rld->extended_response_flag != extended_response) {
 			dev_err(&h->pdev->dev,
 				"report luns requested format %u, got %u\n",
 				extended_response,
-				buf->extended_response_flag);
+				rld->extended_response_flag);
 			rc = -1;
 		}
 	}
@@ -2391,10 +2523,10 @@ out:
 }
 
 static inline int hpsa_scsi_do_report_phys_luns(struct ctlr_info *h,
-		struct ReportLUNdata *buf,
-		int bufsize, int extended_response)
+		struct ReportExtendedLUNdata *buf, int bufsize)
 {
-	return hpsa_scsi_do_report_luns(h, 0, buf, bufsize, extended_response);
+	return hpsa_scsi_do_report_luns(h, 0, buf, bufsize,
+						HPSA_REPORT_PHYS_EXTENDED);
 }
 
 static inline int hpsa_scsi_do_report_log_luns(struct ctlr_info *h,
@@ -2569,6 +2701,7 @@ static int hpsa_update_device_info(struct ctlr_info *h,
 		this_device->offload_config = 0;
 		this_device->offload_enabled = 0;
 		this_device->volume_offline = 0;
+		this_device->queue_depth = h->nr_cmds;
 	}
 
 	if (is_OBDR_device) {
@@ -2711,7 +2844,6 @@ static int hpsa_get_pdisk_of_ioaccel2(struct ctlr_info *h,
 {
 	struct ReportExtendedLUNdata *physicals = NULL;
 	int responsesize = 24;	/* size of physical extended response */
-	int extended = 2;	/* flag forces reporting 'other dev info'. */
 	int reportsize = sizeof(*physicals) + HPSA_MAX_PHYS_LUN * responsesize;
 	u32 nphysicals = 0;	/* number of reported physical devs */
 	int found = 0;		/* found match (1) or not (0) */
@@ -2758,8 +2890,7 @@ static int hpsa_get_pdisk_of_ioaccel2(struct ctlr_info *h,
 	physicals = kzalloc(reportsize, GFP_KERNEL);
 	if (physicals == NULL)
 		return 0;
-	if (hpsa_scsi_do_report_phys_luns(h, (struct ReportLUNdata *) physicals,
-		reportsize, extended)) {
+	if (hpsa_scsi_do_report_phys_luns(h, physicals, reportsize)) {
 		dev_err(&h->pdev->dev,
 			"Can't lookup %s device handle: report physical LUNs failed.\n",
 			"HP SSD Smart Path");
@@ -2800,34 +2931,20 @@ static int hpsa_get_pdisk_of_ioaccel2(struct ctlr_info *h,
  * Returns 0 on success, -1 otherwise.
  */
 static int hpsa_gather_lun_info(struct ctlr_info *h,
-	int reportphyslunsize, int reportloglunsize,
-	struct ReportLUNdata *physdev, u32 *nphysicals, int *physical_mode,
+	struct ReportExtendedLUNdata *physdev, u32 *nphysicals,
 	struct ReportLUNdata *logdev, u32 *nlogicals)
 {
-	int physical_entry_size = 8;
-
-	*physical_mode = 0;
-
-	/* For I/O accelerator mode we need to read physical device handles */
-	if (h->transMethod & CFGTBL_Trans_io_accel1 ||
-		h->transMethod & CFGTBL_Trans_io_accel2) {
-		*physical_mode = HPSA_REPORT_PHYS_EXTENDED;
-		physical_entry_size = 24;
-	}
-	if (hpsa_scsi_do_report_phys_luns(h, physdev, reportphyslunsize,
-							*physical_mode)) {
+	if (hpsa_scsi_do_report_phys_luns(h, physdev, sizeof(*physdev))) {
 		dev_err(&h->pdev->dev, "report physical LUNs failed.\n");
 		return -1;
 	}
-	*nphysicals = be32_to_cpu(*((__be32 *)physdev->LUNListLength)) /
-							physical_entry_size;
+	*nphysicals = be32_to_cpu(*((__be32 *)physdev->LUNListLength)) / 24;
 	if (*nphysicals > HPSA_MAX_PHYS_LUN) {
-		dev_warn(&h->pdev->dev, "maximum physical LUNs (%d) exceeded."
-			"  %d LUNs ignored.\n", HPSA_MAX_PHYS_LUN,
-			*nphysicals - HPSA_MAX_PHYS_LUN);
+		dev_warn(&h->pdev->dev, "maximum physical LUNs (%d) exceeded. %d LUNs ignored.\n",
+			HPSA_MAX_PHYS_LUN, *nphysicals - HPSA_MAX_PHYS_LUN);
 		*nphysicals = HPSA_MAX_PHYS_LUN;
 	}
-	if (hpsa_scsi_do_report_log_luns(h, logdev, reportloglunsize)) {
+	if (hpsa_scsi_do_report_log_luns(h, logdev, sizeof(*logdev))) {
 		dev_err(&h->pdev->dev, "report logical LUNs failed.\n");
 		return -1;
 	}
@@ -2900,6 +3017,33 @@ static int hpsa_hba_mode_enabled(struct ctlr_info *h)
 	return hba_mode_enabled;
 }
 
+/* get physical drive ioaccel handle and queue depth */
+static void hpsa_get_ioaccel_drive_info(struct ctlr_info *h,
+		struct hpsa_scsi_dev_t *dev,
+		u8 *lunaddrbytes,
+		struct bmic_identify_physical_device *id_phys)
+{
+	int rc;
+	struct ext_report_lun_entry *rle =
+		(struct ext_report_lun_entry *) lunaddrbytes;
+
+	dev->ioaccel_handle = rle->ioaccel_handle;
+	memset(id_phys, 0, sizeof(*id_phys));
+	rc = hpsa_bmic_id_physical_device(h, lunaddrbytes,
+			GET_BMIC_DRIVE_NUMBER(lunaddrbytes), id_phys,
+			sizeof(*id_phys));
+	if (!rc)
+		/* Reserve space for FW operations */
+#define DRIVE_CMDS_RESERVED_FOR_FW 2
+#define DRIVE_QUEUE_DEPTH 7
+		dev->queue_depth =
+			le16_to_cpu(id_phys->current_queue_depth_limit) -
+				DRIVE_CMDS_RESERVED_FOR_FW;
+	else
+		dev->queue_depth = DRIVE_QUEUE_DEPTH; /* conservative */
+	atomic_set(&dev->ioaccel_cmds_out, 0);
+}
+
 static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 {
 	/* the idea here is we could get notified
@@ -2914,9 +3058,9 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 	 */
 	struct ReportExtendedLUNdata *physdev_list = NULL;
 	struct ReportLUNdata *logdev_list = NULL;
+	struct bmic_identify_physical_device *id_phys = NULL;
 	u32 nphysicals = 0;
 	u32 nlogicals = 0;
-	int physical_mode = 0;
 	u32 ndev_allocated = 0;
 	struct hpsa_scsi_dev_t **currentsd, *this_device, *tmpdevice;
 	int ncurrent = 0;
@@ -2929,8 +3073,10 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 	physdev_list = kzalloc(sizeof(*physdev_list), GFP_KERNEL);
 	logdev_list = kzalloc(sizeof(*logdev_list), GFP_KERNEL);
 	tmpdevice = kzalloc(sizeof(*tmpdevice), GFP_KERNEL);
+	id_phys = kzalloc(sizeof(*id_phys), GFP_KERNEL);
 
-	if (!currentsd || !physdev_list || !logdev_list || !tmpdevice) {
+	if (!currentsd || !physdev_list || !logdev_list ||
+		!tmpdevice || !id_phys) {
 		dev_err(&h->pdev->dev, "out of memory\n");
 		goto out;
 	}
@@ -2947,10 +3093,8 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 
 	h->hba_mode_enabled = rescan_hba_mode;
 
-	if (hpsa_gather_lun_info(h,
-			sizeof(*physdev_list), sizeof(*logdev_list),
-			(struct ReportLUNdata *) physdev_list, &nphysicals,
-			&physical_mode, logdev_list, &nlogicals))
+	if (hpsa_gather_lun_info(h, physdev_list, &nphysicals,
+			logdev_list, &nlogicals))
 		goto out;
 
 	/* We might see up to the maximum number of logical and physical disks
@@ -3047,10 +3191,11 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 				ncurrent++;
 				break;
 			}
-			if (physical_mode == HPSA_REPORT_PHYS_EXTENDED) {
-				memcpy(&this_device->ioaccel_handle,
-					&lunaddrbytes[20],
-					sizeof(this_device->ioaccel_handle));
+			if (h->transMethod & CFGTBL_Trans_io_accel1 ||
+				h->transMethod & CFGTBL_Trans_io_accel2) {
+				hpsa_get_ioaccel_drive_info(h, this_device,
+							lunaddrbytes, id_phys);
+				atomic_set(&this_device->ioaccel_cmds_out, 0);
 				ncurrent++;
 			}
 			break;
@@ -3074,6 +3219,7 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h, int hostno)
 		if (ncurrent >= HPSA_MAX_DEVICES)
 			break;
 	}
+	hpsa_update_log_drive_phys_drive_ptrs(h, currentsd, ncurrent);
 	adjust_hpsa_scsi_table(h, hostno, currentsd, ncurrent);
 out:
 	kfree(tmpdevice);
@@ -3082,6 +3228,7 @@ out:
 	kfree(currentsd);
 	kfree(physdev_list);
 	kfree(logdev_list);
+	kfree(id_phys);
 }
 
 /*
@@ -3197,7 +3344,7 @@ static int fixup_ioaccel_cdb(u8 *cdb, int *cdb_len)
 
 static int hpsa_scsi_ioaccel1_queue_command(struct ctlr_info *h,
 	struct CommandList *c, u32 ioaccel_handle, u8 *cdb, int cdb_len,
-	u8 *scsi3addr)
+	u8 *scsi3addr, struct hpsa_scsi_dev_t *phys_disk)
 {
 	struct scsi_cmnd *cmd = c->scsi_cmd;
 	struct io_accel1_cmd *cp = &h->ioaccel_cmd_pool[c->cmdindex];
@@ -3210,13 +3357,17 @@ static int hpsa_scsi_ioaccel1_queue_command(struct ctlr_info *h,
 	u32 control = IOACCEL1_CONTROL_SIMPLEQUEUE;
 
 	/* TODO: implement chaining support */
-	if (scsi_sg_count(cmd) > h->ioaccel_maxsg)
+	if (scsi_sg_count(cmd) > h->ioaccel_maxsg) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return IO_ACCEL_INELIGIBLE;
+	}
 
 	BUG_ON(cmd->cmd_len > IOACCEL1_IOFLAGS_CDBLEN_MAX);
 
-	if (fixup_ioaccel_cdb(cdb, &cdb_len))
+	if (fixup_ioaccel_cdb(cdb, &cdb_len)) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return IO_ACCEL_INELIGIBLE;
+	}
 
 	c->cmd_type = CMD_IOACCEL1;
 
@@ -3226,8 +3377,10 @@ static int hpsa_scsi_ioaccel1_queue_command(struct ctlr_info *h,
 	BUG_ON(c->busaddr & 0x0000007F);
 
 	use_sg = scsi_dma_map(cmd);
-	if (use_sg < 0)
+	if (use_sg < 0) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return use_sg;
+	}
 
 	if (use_sg) {
 		curr_sg = cp->SG;
@@ -3286,8 +3439,10 @@ static int hpsa_scsi_ioaccel_direct_map(struct ctlr_info *h,
 	struct scsi_cmnd *cmd = c->scsi_cmd;
 	struct hpsa_scsi_dev_t *dev = cmd->device->hostdata;
 
+	c->phys_disk = dev;
+
 	return hpsa_scsi_ioaccel_queue_command(h, c, dev->ioaccel_handle,
-		cmd->cmnd, cmd->cmd_len, dev->scsi3addr);
+		cmd->cmnd, cmd->cmd_len, dev->scsi3addr, dev);
 }
 
 /*
@@ -3351,7 +3506,7 @@ static void set_encrypt_ioaccel2(struct ctlr_info *h,
 
 static int hpsa_scsi_ioaccel2_queue_command(struct ctlr_info *h,
 	struct CommandList *c, u32 ioaccel_handle, u8 *cdb, int cdb_len,
-	u8 *scsi3addr)
+	u8 *scsi3addr, struct hpsa_scsi_dev_t *phys_disk)
 {
 	struct scsi_cmnd *cmd = c->scsi_cmd;
 	struct io_accel2_cmd *cp = &h->ioaccel2_cmd_pool[c->cmdindex];
@@ -3362,11 +3517,16 @@ static int hpsa_scsi_ioaccel2_queue_command(struct ctlr_info *h,
 	u32 len;
 	u32 total_len = 0;
 
-	if (scsi_sg_count(cmd) > h->ioaccel_maxsg)
+	if (scsi_sg_count(cmd) > h->ioaccel_maxsg) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return IO_ACCEL_INELIGIBLE;
+	}
 
-	if (fixup_ioaccel_cdb(cdb, &cdb_len))
+	if (fixup_ioaccel_cdb(cdb, &cdb_len)) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return IO_ACCEL_INELIGIBLE;
+	}
+
 	c->cmd_type = CMD_IOACCEL2;
 	/* Adjust the DMA address to point to the accelerated command buffer */
 	c->busaddr = (u32) h->ioaccel2_cmd_pool_dhandle +
@@ -3377,8 +3537,10 @@ static int hpsa_scsi_ioaccel2_queue_command(struct ctlr_info *h,
 	cp->IU_type = IOACCEL2_IU_TYPE;
 
 	use_sg = scsi_dma_map(cmd);
-	if (use_sg < 0)
+	if (use_sg < 0) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
 		return use_sg;
+	}
 
 	if (use_sg) {
 		BUG_ON(use_sg > IOACCEL2_MAXSGENTRIES);
@@ -3444,14 +3606,22 @@ static int hpsa_scsi_ioaccel2_queue_command(struct ctlr_info *h,
  */
 static int hpsa_scsi_ioaccel_queue_command(struct ctlr_info *h,
 	struct CommandList *c, u32 ioaccel_handle, u8 *cdb, int cdb_len,
-	u8 *scsi3addr)
+	u8 *scsi3addr, struct hpsa_scsi_dev_t *phys_disk)
 {
+	/* Try to honor the device's queue depth */
+	if (atomic_inc_return(&phys_disk->ioaccel_cmds_out) >
+					phys_disk->queue_depth) {
+		atomic_dec(&phys_disk->ioaccel_cmds_out);
+		return IO_ACCEL_INELIGIBLE;
+	}
 	if (h->transMethod & CFGTBL_Trans_io_accel1)
 		return hpsa_scsi_ioaccel1_queue_command(h, c, ioaccel_handle,
-						cdb, cdb_len, scsi3addr);
+						cdb, cdb_len, scsi3addr,
+						phys_disk);
 	else
 		return hpsa_scsi_ioaccel2_queue_command(h, c, ioaccel_handle,
-						cdb, cdb_len, scsi3addr);
+						cdb, cdb_len, scsi3addr,
+						phys_disk);
 }
 
 static void raid_map_helper(struct raid_map_data *map,
@@ -3755,6 +3925,8 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
 		return IO_ACCEL_INELIGIBLE;
 	}
 
+	c->phys_disk = dev->phys_disk[map_index];
+
 	disk_handle = dd[map_index].ioaccel_handle;
 	disk_block = le64_to_cpu(map->disk_starting_blk) +
 			first_row * le16_to_cpu(map->strip_size) +
@@ -3802,7 +3974,8 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
 		cdb_len = 10;
 	}
 	return hpsa_scsi_ioaccel_queue_command(h, c, disk_handle, cdb, cdb_len,
-						dev->scsi3addr);
+						dev->scsi3addr,
+						dev->phys_disk[map_index]);
 }
 
 /* Submit commands down the "normal" RAID stack path */
@@ -4016,15 +4189,17 @@ static void hpsa_scan_start(struct Scsi_Host *sh)
 
 static int hpsa_change_queue_depth(struct scsi_device *sdev, int qdepth)
 {
-	struct ctlr_info *h = sdev_to_hba(sdev);
+	struct hpsa_scsi_dev_t *logical_drive = sdev->hostdata;
+
+	if (!logical_drive)
+		return -ENODEV;
 
 	if (qdepth < 1)
 		qdepth = 1;
-	else
-		if (qdepth > h->nr_cmds)
-			qdepth = h->nr_cmds;
-	scsi_change_queue_depth(sdev, qdepth);
-	return sdev->queue_depth;
+	else if (qdepth > logical_drive->queue_depth)
+		qdepth = logical_drive->queue_depth;
+
+	return scsi_change_queue_depth(sdev, qdepth);
 }
 
 static int hpsa_scan_finished(struct Scsi_Host *sh,
@@ -4068,10 +4243,7 @@ static int hpsa_register_scsi(struct ctlr_info *h)
 			HPSA_CMDS_RESERVED_FOR_ABORTS -
 			HPSA_CMDS_RESERVED_FOR_DRIVER -
 			HPSA_MAX_CONCURRENT_PASSTHRUS;
-	if (h->hba_mode_enabled)
-		sh->cmd_per_lun = 7;
-	else
-		sh->cmd_per_lun = sh->can_queue;
+	sh->cmd_per_lun = sh->can_queue;
 	sh->sg_tablesize = h->maxsgentries;
 	h->scsi_host = sh;
 	sh->hostdata[0] = (unsigned long) h;
@@ -5090,6 +5262,16 @@ static int fill_cmd(struct CommandList *c, u8 cmd, struct ctlr_info *h,
 			c->Request.CDB[7] = (size >> 16) & 0xFF;
 			c->Request.CDB[8] = (size >> 8) & 0xFF;
 			break;
+		case BMIC_IDENTIFY_PHYSICAL_DEVICE:
+			c->Request.CDBLen = 10;
+			c->Request.type_attr_dir =
+				TYPE_ATTR_DIR(cmd_type, ATTR_SIMPLE, XFER_READ);
+			c->Request.Timeout = 0;
+			c->Request.CDB[0] = BMIC_READ;
+			c->Request.CDB[6] = BMIC_IDENTIFY_PHYSICAL_DEVICE;
+			c->Request.CDB[7] = (size >> 16) & 0xFF;
+			c->Request.CDB[8] = (size >> 8) & 0XFF;
+			break;
 		default:
 			dev_warn(&h->pdev->dev, "unknown command 0x%c\n", cmd);
 			BUG();