scsi: qla2xxx: Select qpair depending on which CPU post_cmd() gets called

In current I/O path, Tx and Rx may not be processed on same CPU. This may
lead to thrashing and optimum performance may not be achieved.

Pick qpair such that Tx and Rx are processed on same CPU.

Signed-off-by: Shreyas Deodhar <sdeodhar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index b0ee307b5d4b..cce6e425c121 100644
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -515,3 +515,58 @@ fcport_is_bigger(fc_port_t *fcport)
 {
 	return !fcport_is_smaller(fcport);
 }
+
+static inline struct qla_qpair *
+qla_mapq_nvme_select_qpair(struct qla_hw_data *ha, struct qla_qpair *qpair)
+{
+	int cpuid = smp_processor_id();
+
+	if (qpair->cpuid != cpuid &&
+	    ha->qp_cpu_map[cpuid]) {
+		qpair = ha->qp_cpu_map[cpuid];
+	}
+	return qpair;
+}
+
+static inline void
+qla_mapq_init_qp_cpu_map(struct qla_hw_data *ha,
+			 struct qla_msix_entry *msix,
+			 struct qla_qpair *qpair)
+{
+	const struct cpumask *mask;
+	unsigned int cpu;
+
+	if (!ha->qp_cpu_map)
+		return;
+	mask = pci_irq_get_affinity(ha->pdev, msix->vector_base0);
+	qpair->cpuid = cpumask_first(mask);
+	for_each_cpu(cpu, mask) {
+		ha->qp_cpu_map[cpu] = qpair;
+	}
+	msix->cpuid = qpair->cpuid;
+}
+
+static inline void
+qla_mapq_free_qp_cpu_map(struct qla_hw_data *ha)
+{
+	if (ha->qp_cpu_map) {
+		kfree(ha->qp_cpu_map);
+		ha->qp_cpu_map = NULL;
+	}
+}
+
+static inline int qla_mapq_alloc_qp_cpu_map(struct qla_hw_data *ha)
+{
+	scsi_qla_host_t *vha = pci_get_drvdata(ha->pdev);
+
+	if (!ha->qp_cpu_map) {
+		ha->qp_cpu_map = kcalloc(NR_CPUS, sizeof(struct qla_qpair *),
+					 GFP_KERNEL);
+		if (!ha->qp_cpu_map) {
+			ql_log(ql_log_fatal, vha, 0x0180,
+			       "Unable to allocate memory for qp_cpu_map ptrs.\n");
+			return -1;
+		}
+	}
+	return 0;
+}