scsi: mpt3sas: Add flag high_iops_queues

Aero controllers support balanced performance mode through the ability to
configure queues with different properties.

Reply queues with interrupt coalescing enabled are called "high iops reply
queues" and reply queues with interrupt coalescing disabled are called "low
latency reply queues".

The driver configures a combination of high iops and low latency reply
queues if:

 - HBA is an AERO controller;

 - MSI-X vectors supported by the HBA is 128;

 - Total CPU count in the system more than high iops queue count;

 - Driver is loaded with default max_msix_vectors module parameter; and

 - System booted in non-kdump mode.

Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -2912,6 +2912,34 @@ _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc)
 	}
 }
 
+/**
+ * _base_check_and_enable_high_iops_queues - enable high iops mode
+ * @ ioc - per adapter object
+ * @ hba_msix_vector_count - msix vectors supported by HBA
+ *
+ * Enable high iops queues only if
+ *  - HBA is a SEA/AERO controller and
+ *  - MSI-Xs vector supported by the HBA is 128 and
+ *  - total CPU count in the system >=16 and
+ *  - loaded driver with default max_msix_vectors module parameter and
+ *  - system booted in non kdump mode
+ *
+ * returns nothing.
+ */
+static void
+_base_check_and_enable_high_iops_queues(struct MPT3SAS_ADAPTER *ioc,
+		int hba_msix_vector_count)
+{
+
+	if (!reset_devices && ioc->is_aero_ioc &&
+	    hba_msix_vector_count == MPT3SAS_GEN35_MAX_MSIX_QUEUES &&
+	    num_online_cpus() >= MPT3SAS_HIGH_IOPS_REPLY_QUEUES &&
+	    max_msix_vectors == -1)
+		ioc->high_iops_queues = MPT3SAS_HIGH_IOPS_REPLY_QUEUES;
+	else
+		ioc->high_iops_queues = 0;
+}
+
 /**
  * _base_disable_msix - disables msix
  * @ioc: per adapter object
@@ -2948,11 +2976,14 @@ _base_enable_msix(struct MPT3SAS_ADAPTER *ioc)
 	if (_base_check_enable_msix(ioc) != 0)
 		goto try_ioapic;
 
-	ioc->reply_queue_count = min_t(int, ioc->cpu_count,
-		ioc->msix_vector_count);
+	ioc_info(ioc, "MSI-X vectors supported: %d\n", ioc->msix_vector_count);
+	pr_info("\t no of cores: %d, max_msix_vectors: %d\n",
+		ioc->cpu_count, max_msix_vectors);
 
-	ioc_info(ioc, "MSI-X vectors supported: %d, no of cores: %d, max_msix_vectors: %d\n",
-		 ioc->msix_vector_count, ioc->cpu_count, max_msix_vectors);
+	_base_check_and_enable_high_iops_queues(ioc, ioc->msix_vector_count);
+	ioc->reply_queue_count =
+		min_t(int, ioc->cpu_count + ioc->high_iops_queues,
+		ioc->msix_vector_count);
 
 	if (!ioc->rdpq_array_enable && max_msix_vectors == -1)
 		local_max_msix_vectors = (reset_devices) ? 1 : 8;
@@ -2991,11 +3022,15 @@ _base_enable_msix(struct MPT3SAS_ADAPTER *ioc)
 		}
 	}
 
+	ioc_info(ioc, "High IOPs queues : %s\n",
+			ioc->high_iops_queues ? "enabled" : "disabled");
+
 	return 0;
 
 /* failback to io_apic interrupt routing */
  try_ioapic:
-
+	ioc->high_iops_queues = 0;
+	ioc_info(ioc, "High IOPs queues : disabled\n");
 	ioc->reply_queue_count = 1;
 	r = pci_alloc_irq_vectors(ioc->pdev, 1, 1, PCI_IRQ_LEGACY);
 	if (r < 0) {

drivers/scsi/mpt3sas/mpt3sas_base.h

@@ -355,6 +355,10 @@ struct mpt3sas_nvme_cmd {
 
 #define VIRTUAL_IO_FAILED_RETRY			(0x32010081)
 
+/* High IOPs definitions */
+#define MPT3SAS_HIGH_IOPS_REPLY_QUEUES		8
+#define MPT3SAS_GEN35_MAX_MSIX_QUEUES		128
+
 /* OEM Specific Flags will come from OEM specific header files */
 struct Mpi2ManufacturingPage10_t {
 	MPI2_CONFIG_PAGE_HEADER	Header;		/* 00h */
@@ -1209,6 +1213,7 @@ struct MPT3SAS_ADAPTER {
 	atomic64_t      total_io_cnt;
 	bool            msix_load_balance;
 	u16		thresh_hold;
+	u8		high_iops_queues;
 
 	/* internal commands, callback index */
 	u8		scsi_io_cb_idx;