scsi: megaraid_sas: SAS3.5 Generic Megaraid Controllers Stream Detection and IO Coalescing

Detect sequential Write IOs and pass the hint that it is part of sequential
stream to help HBA Firmware do the Full Stripe Writes. For read IOs on
certain RAID volumes like Read Ahead volumes,this will help driver to
send it to Firmware even if the IOs can potentially be sent to
hardware directly (called fast path) bypassing firmware.

Design: 8 streams are maintained per RAID volume as per the combined
firmware/driver design. When there is no stream detected the LRU stream
is used for next potential stream and LRU/MRU map is updated to make this
as MRU stream. Every time a stream is detected the MRU map
is updated to make the current stream as MRU stream.

Signed-off-by: Sasikumar Chandrasekaran <sasikumar.pc@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 42 insertions, 1 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 6801a449d236..b2b1d29ec942 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5001,7 +5001,7 @@ static int megasas_init_fw(struct megasas_instance *instance)
 	struct megasas_register_set __iomem *reg_set;
 	struct megasas_ctrl_info *ctrl_info = NULL;
 	unsigned long bar_list;
-	int i, loop, fw_msix_count = 0;
+	int i, j, loop, fw_msix_count = 0;
 	struct IOV_111 *iovPtr;
 	struct fusion_context *fusion;
 
@@ -5194,6 +5194,36 @@ static int megasas_init_fw(struct megasas_instance *instance)
 	}
 
 	memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
+
+	/* stream detection initialization */
+	if (instance->is_ventura) {
+		fusion->stream_detect_by_ld =
+		kzalloc(sizeof(struct LD_STREAM_DETECT *)
+		* MAX_LOGICAL_DRIVES_EXT,
+		GFP_KERNEL);
+		if (!fusion->stream_detect_by_ld) {
+			dev_err(&instance->pdev->dev,
+					"unable to allocate stream detection for pool of LDs\n");
+			goto fail_get_ld_pd_list;
+		}
+		for (i = 0; i < MAX_LOGICAL_DRIVES_EXT; ++i) {
+			fusion->stream_detect_by_ld[i] =
+				kmalloc(sizeof(struct LD_STREAM_DETECT),
+				GFP_KERNEL);
+			if (!fusion->stream_detect_by_ld[i]) {
+				dev_err(&instance->pdev->dev,
+					"unable to allocate stream detect by LD\n ");
+				for (j = 0; j < i; ++j)
+					kfree(fusion->stream_detect_by_ld[j]);
+				kfree(fusion->stream_detect_by_ld);
+				fusion->stream_detect_by_ld = NULL;
+				goto fail_get_ld_pd_list;
+			}
+			fusion->stream_detect_by_ld[i]->mru_bit_map
+				= MR_STREAM_BITMAP;
+		}
+	}
+
 	if (megasas_ld_list_query(instance,
 				  MR_LD_QUERY_TYPE_EXPOSED_TO_HOST))
 		megasas_get_ld_list(instance);
@@ -5313,6 +5343,8 @@ static int megasas_init_fw(struct megasas_instance *instance)
 
 	return 0;
 
+fail_get_ld_pd_list:
+	instance->instancet->disable_intr(instance);
 fail_get_pd_list:
 	instance->instancet->disable_intr(instance);
 fail_init_adapter:
@@ -5846,6 +5878,7 @@ static int megasas_probe_one(struct pci_dev *pdev,
 
 	spin_lock_init(&instance->mfi_pool_lock);
 	spin_lock_init(&instance->hba_lock);
+	spin_lock_init(&instance->stream_lock);
 	spin_lock_init(&instance->completion_lock);
 
 	mutex_init(&instance->reset_mutex);
@@ -6353,6 +6386,14 @@ skip_firing_dcmds:
 	if (instance->msix_vectors)
 		pci_free_irq_vectors(instance->pdev);
 
+	if (instance->is_ventura) {
+		for (i = 0; i < MAX_LOGICAL_DRIVES_EXT; ++i)
+			kfree(fusion->stream_detect_by_ld[i]);
+		kfree(fusion->stream_detect_by_ld);
+		fusion->stream_detect_by_ld = NULL;
+	}
+
+
 	if (instance->ctrl_context) {
 		megasas_release_fusion(instance);
 			pd_seq_map_sz = sizeof(struct MR_PD_CFG_SEQ_NUM_SYNC) +