scsi: mpi3mr: Add support for more than 1MB I/O

Enhance the driver to get the maximum data length per I/O request from IOC
Facts data and report that to the upper layers.  If the IOC facts data is
not reported then a default I/O size of 1MB is reported to the OS.
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Link: https://lore.kernel.org/r/20230804104248.118924-4-ranjan.kumar@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpi3mr/mpi3mr.h

@@ -66,11 +66,12 @@ extern atomic64_t event_counter;
 #define MPI3MR_NAME_LENGTH	32
 #define IOCNAME			"%s: "
 
-#define MPI3MR_MAX_SECTORS	2048
+#define MPI3MR_DEFAULT_MAX_IO_SIZE	(1 * 1024 * 1024)
 
 /* Definitions for internal SGL and Chain SGL buffers */
 #define MPI3MR_PAGE_SIZE_4K		4096
-#define MPI3MR_SG_DEPTH		(MPI3MR_PAGE_SIZE_4K / sizeof(struct mpi3_sge_common))
+#define MPI3MR_DEFAULT_SGL_ENTRIES	256
+#define MPI3MR_MAX_SGL_ENTRIES		2048
 
 /* Definitions for MAX values for shost */
 #define MPI3MR_MAX_CMDS_LUN	128
@@ -323,6 +324,7 @@ struct mpi3mr_ioc_facts {
 	u16 max_perids;
 	u16 max_pds;
 	u16 max_sasexpanders;
+	u32 max_data_length;
 	u16 max_sasinitiators;
 	u16 max_enclosures;
 	u16 max_pcie_switches;
@@ -959,6 +961,7 @@ struct scmd_priv {
  * @stop_drv_processing: Stop all command processing
  * @device_refresh_on: Don't process the events until devices are refreshed
  * @max_host_ios: Maximum host I/O count
+ * @max_sgl_entries: Max SGL entries per I/O
  * @chain_buf_count: Chain buffer count
  * @chain_buf_pool: Chain buffer pool
  * @chain_sgl_list: Chain SGL list
@@ -1129,6 +1132,7 @@ struct mpi3mr_ioc {
 	u16 max_host_ios;
 	spinlock_t tgtdev_lock;
 	struct list_head tgtdev_list;
+	u16 max_sgl_entries;
 
 	u32 chain_buf_count;
 	struct dma_pool *chain_buf_pool;

drivers/scsi/mpi3mr/mpi3mr_fw.c

@@ -1163,6 +1163,12 @@ mpi3mr_revalidate_factsdata(struct mpi3mr_ioc *mrioc)
 		return -EPERM;
 	}
 
+	if (mrioc->shost->max_sectors != (mrioc->facts.max_data_length / 512))
+		ioc_err(mrioc, "Warning: The maximum data transfer length\n"
+			    "\tchanged after reset: previous(%d), new(%d),\n"
+			    "the driver cannot change this at run time\n",
+			    mrioc->shost->max_sectors * 512, mrioc->facts.max_data_length);
+
 	if ((mrioc->sas_transport_enabled) && (mrioc->facts.ioc_capabilities &
 	    MPI3_IOCFACTS_CAPABILITY_MULTIPATH_ENABLED))
 		ioc_err(mrioc,
@@ -2856,6 +2862,7 @@ static void mpi3mr_process_factsdata(struct mpi3mr_ioc *mrioc,
 	    le16_to_cpu(facts_data->max_pcie_switches);
 	mrioc->facts.max_sasexpanders =
 	    le16_to_cpu(facts_data->max_sas_expanders);
+	mrioc->facts.max_data_length = le16_to_cpu(facts_data->max_data_length);
 	mrioc->facts.max_sasinitiators =
 	    le16_to_cpu(facts_data->max_sas_initiators);
 	mrioc->facts.max_enclosures = le16_to_cpu(facts_data->max_enclosures);
@@ -2893,13 +2900,18 @@ static void mpi3mr_process_factsdata(struct mpi3mr_ioc *mrioc,
 	mrioc->facts.io_throttle_high =
 	    le16_to_cpu(facts_data->io_throttle_high);
 
+	if (mrioc->facts.max_data_length ==
+	    MPI3_IOCFACTS_MAX_DATA_LENGTH_NOT_REPORTED)
+		mrioc->facts.max_data_length = MPI3MR_DEFAULT_MAX_IO_SIZE;
+	else
+		mrioc->facts.max_data_length *= MPI3MR_PAGE_SIZE_4K;
 	/* Store in 512b block count */
 	if (mrioc->facts.io_throttle_data_length)
 		mrioc->io_throttle_data_length =
 		    (mrioc->facts.io_throttle_data_length * 2 * 4);
 	else
 		/* set the length to 1MB + 1K to disable throttle */
-		mrioc->io_throttle_data_length = MPI3MR_MAX_SECTORS + 2;
+		mrioc->io_throttle_data_length = (mrioc->facts.max_data_length / 512) + 2;
 
 	mrioc->io_throttle_high = (mrioc->facts.io_throttle_high * 2 * 1024);
 	mrioc->io_throttle_low = (mrioc->facts.io_throttle_low * 2 * 1024);
@@ -2914,9 +2926,9 @@ static void mpi3mr_process_factsdata(struct mpi3mr_ioc *mrioc,
 	ioc_info(mrioc, "SGEModMask 0x%x SGEModVal 0x%x SGEModShift 0x%x ",
 	    mrioc->facts.sge_mod_mask, mrioc->facts.sge_mod_value,
 	    mrioc->facts.sge_mod_shift);
-	ioc_info(mrioc, "DMA mask %d InitialPE status 0x%x\n",
+	ioc_info(mrioc, "DMA mask %d InitialPE status 0x%x max_data_len (%d)\n",
 	    mrioc->facts.dma_mask, (facts_flags &
-	    MPI3_IOCFACTS_FLAGS_INITIAL_PORT_ENABLE_MASK));
+	    MPI3_IOCFACTS_FLAGS_INITIAL_PORT_ENABLE_MASK), mrioc->facts.max_data_length);
 	ioc_info(mrioc,
 	    "max_dev_per_throttle_group(%d), max_throttle_groups(%d)\n",
 	    mrioc->facts.max_dev_per_tg, mrioc->facts.max_io_throttle_group);
@@ -3414,7 +3426,14 @@ static int mpi3mr_alloc_chain_bufs(struct mpi3mr_ioc *mrioc)
 	if (!mrioc->chain_sgl_list)
 		goto out_failed;
 
-	sz = MPI3MR_PAGE_SIZE_4K;
+	if (mrioc->max_sgl_entries > (mrioc->facts.max_data_length /
+		MPI3MR_PAGE_SIZE_4K))
+		mrioc->max_sgl_entries = mrioc->facts.max_data_length /
+			MPI3MR_PAGE_SIZE_4K;
+	sz = mrioc->max_sgl_entries * sizeof(struct mpi3_sge_common);
+	ioc_info(mrioc, "number of sgl entries=%d chain buffer size=%dKB\n",
+			mrioc->max_sgl_entries, sz/1024);
+
 	mrioc->chain_buf_pool = dma_pool_create("chain_buf pool",
 	    &mrioc->pdev->dev, sz, 16, 0);
 	if (!mrioc->chain_buf_pool) {
@@ -3813,7 +3832,7 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
 	}
 
 	mrioc->max_host_ios = mrioc->facts.max_reqs - MPI3MR_INTERNAL_CMDS_RESVD;
-
+	mrioc->shost->max_sectors = mrioc->facts.max_data_length / 512;
 	mrioc->num_io_throttle_group = mrioc->facts.max_io_throttle_group;
 	atomic_set(&mrioc->pend_large_data_sz, 0);
 

drivers/scsi/mpi3mr/mpi3mr_os.c

@@ -33,6 +33,12 @@ static int logging_level;
 module_param(logging_level, int, 0);
 MODULE_PARM_DESC(logging_level,
 	" bits for enabling additional logging info (default=0)");
+static int max_sgl_entries = MPI3MR_DEFAULT_SGL_ENTRIES;
+module_param(max_sgl_entries, int, 0444);
+MODULE_PARM_DESC(max_sgl_entries,
+	"Preferred max number of SG entries to be used for a single I/O\n"
+	"The actual value will be determined by the driver\n"
+	"(Minimum=256, Maximum=2048, default=256)");
 
 /* Forward declarations*/
 static void mpi3mr_send_event_ack(struct mpi3mr_ioc *mrioc, u8 event,
@@ -3413,7 +3419,7 @@ static int mpi3mr_prepare_sg_scmd(struct mpi3mr_ioc *mrioc,
 		    scsi_bufflen(scmd));
 		return -ENOMEM;
 	}
-	if (sges_left > MPI3MR_SG_DEPTH) {
+	if (sges_left > mrioc->max_sgl_entries) {
 		sdev_printk(KERN_ERR, scmd->device,
 		    "scsi_dma_map returned unsupported sge count %d!\n",
 		    sges_left);
@@ -4818,10 +4824,10 @@ static const struct scsi_host_template mpi3mr_driver_template = {
 	.no_write_same			= 1,
 	.can_queue			= 1,
 	.this_id			= -1,
-	.sg_tablesize			= MPI3MR_SG_DEPTH,
+	.sg_tablesize			= MPI3MR_DEFAULT_SGL_ENTRIES,
 	/* max xfer supported is 1M (2K in 512 byte sized sectors)
 	 */
-	.max_sectors			= 2048,
+	.max_sectors			= (MPI3MR_DEFAULT_MAX_IO_SIZE / 512),
 	.cmd_per_lun			= MPI3MR_MAX_CMDS_LUN,
 	.max_segment_size		= 0xffffffff,
 	.track_queue_depth		= 1,
@@ -5004,6 +5010,16 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	mrioc->pdev = pdev;
 	mrioc->stop_bsgs = 1;
 
+	mrioc->max_sgl_entries = max_sgl_entries;
+	if (max_sgl_entries > MPI3MR_MAX_SGL_ENTRIES)
+		mrioc->max_sgl_entries = MPI3MR_MAX_SGL_ENTRIES;
+	else if (max_sgl_entries < MPI3MR_DEFAULT_SGL_ENTRIES)
+		mrioc->max_sgl_entries = MPI3MR_DEFAULT_SGL_ENTRIES;
+	else {
+		mrioc->max_sgl_entries /= MPI3MR_DEFAULT_SGL_ENTRIES;
+		mrioc->max_sgl_entries *= MPI3MR_DEFAULT_SGL_ENTRIES;
+	}
+
 	/* init shost parameters */
 	shost->max_cmd_len = MPI3MR_MAX_CDB_LENGTH;
 	shost->max_lun = -1;
@@ -5068,7 +5084,7 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		shost->nr_maps = 3;
 
 	shost->can_queue = mrioc->max_host_ios;
-	shost->sg_tablesize = MPI3MR_SG_DEPTH;
+	shost->sg_tablesize = mrioc->max_sgl_entries;
 	shost->max_id = mrioc->facts.max_perids + 1;
 
 	retval = scsi_add_host(shost, &pdev->dev);