[PATCH 01/20] [SCSI] mpt3sas: Added Combined Reply Queue feature to extend up-to 96 MSIX vector support

[Sreekanth Reddy <sreekanth.reddy@avagotech.com>]

In this patch, increased the number of MSIX vector support for SAS3 C0 HBAs to up-to 96.

Following are changes that are done in this patch
1. Support this feature only for SAS3 C0 cards and also only when reply post free queue count is greater than 8.
2. Instead of using single ReplyPostHostIndex system interface, here 12 ReplyPostHostIndex system interfaces are used. reply post free queues numbered from 0 to 7 use the first ReplyPostHostIndex system interface to update its corresponding ReplyPostHostIndex values, reply post free queues numbered from 8 to 15 will use the second ReplyPostHostIndex system interface and so on. These 12 ReplyPostHostIndex system interfaces address are saved in the array replyPostRegisterIndex[].
3. Update the ReplyPostHostIndex value of corresponding reply post free queue in the (its msix_index/8)th entry of replyPostRegisterIndex[] array after processing the reply post descriptor.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c | 70 +++++++++++++++++++++++++++++++++----
 drivers/scsi/mpt3sas/mpt3sas_base.h |  7 +++-
 2 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 14a781b..c13a365 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -83,7 +83,7 @@ static int msix_disable = -1;
 module_param(msix_disable, int, 0);
 MODULE_PARM_DESC(msix_disable, " disable msix routed interrupts (default=0)");
 
-static int max_msix_vectors = 8;
+static int max_msix_vectors = -1;
 module_param(max_msix_vectors, int, 0);
 MODULE_PARM_DESC(max_msix_vectors,
 	" max msix vectors - (default=8)");
@@ -1009,8 +1009,15 @@ _base_interrupt(int irq, void *bus_id)
 	}
 
 	wmb();
-	writel(reply_q->reply_post_host_index | (msix_index <<
-	    MPI2_RPHI_MSIX_INDEX_SHIFT), &ioc->chip->ReplyPostHostIndex);
+	if (ioc->msix96_vector) {
+		writel(reply_q->reply_post_host_index | ((msix_index  & 7) <<
+			MPI2_RPHI_MSIX_INDEX_SHIFT),
+				ioc->replyPostRegisterIndex[msix_index/8]);
+	} else {
+		writel(reply_q->reply_post_host_index | (msix_index <<
+			MPI2_RPHI_MSIX_INDEX_SHIFT),
+				&ioc->chip->ReplyPostHostIndex);
+	}
 	atomic_dec(&reply_q->busy);
 	return IRQ_HANDLED;
 }
@@ -1560,8 +1567,6 @@ _base_check_enable_msix(struct MPT3SAS_ADAPTER *ioc)
 
 	pci_read_config_word(ioc->pdev, base + 2, &message_control);
 	ioc->msix_vector_count = (message_control & 0x3FF) + 1;
-	if (ioc->msix_vector_count > 8)
-		ioc->msix_vector_count = 8;
 	dinitprintk(ioc, pr_info(MPT3SAS_FMT
 		"msix is supported, vector_count(%d)\n",
 		ioc->name, ioc->msix_vector_count));
@@ -1880,6 +1885,31 @@ mpt3sas_base_map_resources(struct MPT3SAS_ADAPTER *ioc)
 	if (r)
 		goto out_fail;
 
+	/* Use the Combined reply queue feature only for SAS3 C0 HBAs and
+	 * also only when reply queue count is greater than 8
+	 */
+	if (ioc->msix96_vector && ioc->reply_queue_count > 8) {
+		/* If this is an 96 vector supported device,
+		set up ReplyPostIndex addresses */
+		ioc->replyPostRegisterIndex = kcalloc(12,
+			sizeof(resource_size_t *), GFP_KERNEL);
+		if (!ioc->replyPostRegisterIndex) {
+			dfailprintk(ioc, printk(MPT3SAS_FMT
+			"allocation for reply Post Register Index failed!!!\n",
+								   ioc->name));
+			r = -ENOMEM;
+			goto out_fail;
+		}
+
+		for (i = 0; i < 12; i++) {
+			ioc->replyPostRegisterIndex[i] = (resource_size_t *)
+				((u8 *)&ioc->chip->Doorbell +
+				MPI25_SUP_REPLY_POST_HOST_INDEX_OFFSET +
+				(i * 0x10));
+		}
+	} else
+		ioc->msix96_vector = 0;
+
 	list_for_each_entry(reply_q, &ioc->reply_queue_list, list)
 		pr_info(MPT3SAS_FMT "%s: IRQ %d\n",
 		    reply_q->name,  ((ioc->msix_enable) ? "PCI-MSI-X enabled" :
@@ -1901,6 +1931,8 @@ mpt3sas_base_map_resources(struct MPT3SAS_ADAPTER *ioc)
 	pci_release_selected_regions(ioc->pdev, ioc->bars);
 	pci_disable_pcie_error_reporting(pdev);
 	pci_disable_device(pdev);
+	if (ioc->msix96_vector)
+		kfree(ioc->replyPostRegisterIndex);
 	return r;
 }
 
@@ -4522,8 +4554,16 @@ _base_make_ioc_operational(struct MPT3SAS_ADAPTER *ioc, int sleep_flag)
 
 	/* initialize reply post host index */
 	list_for_each_entry(reply_q, &ioc->reply_queue_list, list) {
-		writel(reply_q->msix_index << MPI2_RPHI_MSIX_INDEX_SHIFT,
-		    &ioc->chip->ReplyPostHostIndex);
+		if (ioc->msix96_vector) {
+			writel((reply_q->msix_index & 7)<<
+			   MPI2_RPHI_MSIX_INDEX_SHIFT,
+			   ioc->replyPostRegisterIndex[reply_q->msix_index/8]);
+		} else {
+			writel(reply_q->msix_index <<
+				MPI2_RPHI_MSIX_INDEX_SHIFT,
+					&ioc->chip->ReplyPostHostIndex);
+		}
+
 		if (!_base_is_controller_msix_enabled(ioc))
 			goto skip_init_reply_post_host_index;
 	}
@@ -4577,6 +4617,9 @@ mpt3sas_base_free_resources(struct MPT3SAS_ADAPTER *ioc)
 	_base_free_irq(ioc);
 	_base_disable_msix(ioc);
 
+	if (ioc->msix96_vector)
+		kfree(ioc->replyPostRegisterIndex);
+
 	if (ioc->chip_phys && ioc->chip)
 		iounmap(ioc->chip);
 	ioc->chip_phys = 0;
@@ -4600,6 +4643,7 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 {
 	int r, i;
 	int cpu_id, last_cpu_id = 0;
+	u8 revision;
 
 	dinitprintk(ioc, pr_info(MPT3SAS_FMT "%s\n", ioc->name,
 	    __func__));
@@ -4618,6 +4662,18 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 		r = -ENOMEM;
 		goto out_free_resources;
 	}
+	/* Check whether the controller revision is C0 or above.
+	    C0 and above revision controllers support 96 vectors */
+	revision = ioc->pdev->revision;
+
+	if ((ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3004 ||
+	     ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3008 ||
+	     ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3108_1 ||
+	     ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3108_2 ||
+	     ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3108_5 ||
+	     ioc->pdev->device == MPI25_MFGPAGE_DEVID_SAS3108_6) &&
+	     (revision >= 0x02))
+		ioc->msix96_vector = 1;
 
 	ioc->rdpq_array_enable_assigned = 0;
 	ioc->dma_mask = 0;
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index afa8816..6b8d8f1 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -728,7 +728,8 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
  *				is assigned only ones
  * @reply_queue_count: number of reply queue's
  * @reply_queue_list: link list contaning the reply queue info
- * @reply_post_host_index: head index in the pool where FW completes IO
+ * @msix96_vector: 96 MSI-X vector support
+ * @replyPostRegisterIndex: index of next position in Reply Desc Post Queue
  * @delayed_tr_list: target reset link list
  * @delayed_tr_volume_list: volume target reset link list
  * @@temp_sensors_count: flag to carry the number of temperature sensors
@@ -937,6 +938,10 @@ struct MPT3SAS_ADAPTER {
 	u8		reply_queue_count;
 	struct list_head reply_queue_list;
 
+	u8		msix96_vector;
+	/* reply post register index */
+	resource_size_t	**replyPostRegisterIndex;
+
 	struct list_head delayed_tr_list;
 	struct list_head delayed_tr_volume_list;
 	u8		temp_sensors_count;
-- 
2.0.2