qla2xxx: Add irq affinity notification

Register to receive notification of when irq setting change
occured.

Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 93 insertions, 1 deletions

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 216a944c1ca5..c4fc32e9aaf9 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2714,11 +2714,16 @@ struct isp_operations {
 
 struct scsi_qla_host;
 
+
+#define QLA83XX_RSPQ_MSIX_ENTRY_NUMBER 1 /* refer to qla83xx_msix_entries */
+
 struct qla_msix_entry {
         int have_irq;
         uint32_t vector;
         uint16_t entry;
         struct rsp_que *rsp;
+        struct irq_affinity_notify irq_notify;
+        int cpuid;
 };
 
 #define WATCH_INTERVAL          1       /* number of seconds */
@@ -2930,6 +2935,7 @@ struct qlt_hw_data {
         spinlock_t q_full_lock;
         uint32_t leak_exchg_thresh_hold;
         spinlock_t sess_lock;
+        int rspq_vector_cpuid;
 };
 
 #define MAX_QFULL_CMDS_ALLOC    8192
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index ea7e8e8a065a..cf0fe8ec12c7 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -18,6 +18,10 @@ static void qla2x00_status_entry(scsi_qla_host_t *, struct rsp_que *, void *);
 static void qla2x00_status_cont_entry(struct rsp_que *, sts_cont_entry_t *);
 static void qla2x00_error_entry(scsi_qla_host_t *, struct rsp_que *,
         sts_entry_t *);
+static void qla_irq_affinity_notify(struct irq_affinity_notify *,
+    const cpumask_t *);
+static void qla_irq_affinity_release(struct kref *);
+
 
 /**
  * qla2100_intr_handler() - Process interrupts for the ISP2100 and ISP2200.
@@ -2548,6 +2552,14 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
         if (!vha->flags.online)
                 return;
 
+        if (rsp->msix->cpuid != smp_processor_id()) {
+                /* if kernel does not notify qla of IRQ's CPU change,
+                 * then set it here.
+                 */
+                rsp->msix->cpuid = smp_processor_id();
+                ha->tgt.rspq_vector_cpuid = rsp->msix->cpuid;
+        }
+
         while (rsp->ring_ptr->signature != RESPONSE_PROCESSED) {
                 pkt = (struct sts_entry_24xx *)rsp->ring_ptr;
 
@@ -2979,8 +2991,11 @@ qla24xx_disable_msix(struct qla_hw_data *ha)
 
         for (i = 0; i < ha->msix_count; i++) {
                 qentry = &ha->msix_entries[i];
-                if (qentry->have_irq)
+                if (qentry->have_irq) {
+                        /* un-register irq cpu affinity notification */
+                        irq_set_affinity_notifier(qentry->vector, NULL);
                         free_irq(qentry->vector, qentry->rsp);
+                }
         }
         pci_disable_msix(ha->pdev);
         kfree(ha->msix_entries);
@@ -3043,6 +3058,9 @@ qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
                 qentry->entry = entries[i].entry;
                 qentry->have_irq = 0;
                 qentry->rsp = NULL;
+                qentry->irq_notify.notify  = qla_irq_affinity_notify;
+                qentry->irq_notify.release = qla_irq_affinity_release;
+                qentry->cpuid = -1;
         }
 
         /* Enable MSI-X vectors for the base queue */
@@ -3061,6 +3079,18 @@ qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
                 qentry->have_irq = 1;
                 qentry->rsp = rsp;
                 rsp->msix = qentry;
+
+                /* Register for CPU affinity notification. */
+                irq_set_affinity_notifier(qentry->vector, &qentry->irq_notify);
+
+                /* Schedule work (ie. trigger a notification) to read cpu
+                 * mask for this specific irq.
+                 * kref_get is required because
+                * irq_affinity_notify() will do
+                * kref_put().
+                */
+                kref_get(&qentry->irq_notify.kref);
+                schedule_work(&qentry->irq_notify.work);
         }
 
         /*
@@ -3240,3 +3270,47 @@ int qla25xx_request_irq(struct rsp_que *rsp)
         msix->rsp = rsp;
         return ret;
 }
+
+
+/* irq_set_affinity/irqbalance will trigger notification of cpu mask update */
+static void qla_irq_affinity_notify(struct irq_affinity_notify *notify,
+        const cpumask_t *mask)
+{
+        struct qla_msix_entry *e =
+                container_of(notify, struct qla_msix_entry, irq_notify);
+        struct qla_hw_data *ha;
+        struct scsi_qla_host *base_vha;
+
+        /* user is recommended to set mask to just 1 cpu */
+        e->cpuid = cpumask_first(mask);
+
+        ha = e->rsp->hw;
+        base_vha = pci_get_drvdata(ha->pdev);
+
+        ql_dbg(ql_dbg_init, base_vha, 0xffff,
+            "%s: host %ld : vector %d cpu %d \n", __func__,
+            base_vha->host_no, e->vector, e->cpuid);
+
+        if (e->have_irq) {
+                if ((IS_QLA83XX(ha) || IS_QLA27XX(ha)) &&
+                    (e->entry == QLA83XX_RSPQ_MSIX_ENTRY_NUMBER)) {
+                        ha->tgt.rspq_vector_cpuid = e->cpuid;
+                        ql_dbg(ql_dbg_init, base_vha, 0xffff,
+                            "%s: host%ld: rspq vector %d cpu %d  runtime change\n",
+                            __func__, base_vha->host_no, e->vector, e->cpuid);
+                }
+        }
+}
+
+void qla_irq_affinity_release(struct kref *ref)
+{
+        struct irq_affinity_notify *notify =
+                container_of(ref, struct irq_affinity_notify, kref);
+        struct qla_msix_entry *e =
+                container_of(notify, struct qla_msix_entry, irq_notify);
+        struct scsi_qla_host *base_vha = pci_get_drvdata(e->rsp->hw->pdev);
+
+        ql_dbg(ql_dbg_init, base_vha, 0xffff,
+            "%s: host%ld: vector %d cpu %d \n", __func__,
+            base_vha->host_no, e->vector, e->cpuid);
+}
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index 6136987df164..9a4aed0e8241 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -6232,6 +6232,7 @@ qlt_enable_vha(struct scsi_qla_host *vha)
         struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
         unsigned long flags;
         scsi_qla_host_t *base_vha = pci_get_drvdata(ha->pdev);
+        int rspq_ent = QLA83XX_RSPQ_MSIX_ENTRY_NUMBER;
 
         if (!tgt) {
                 ql_dbg(ql_dbg_tgt, vha, 0xe069,
@@ -6250,6 +6251,17 @@ qlt_enable_vha(struct scsi_qla_host *vha)
                 qla24xx_disable_vp(vha);
                 qla24xx_enable_vp(vha);
         } else {
+                if (ha->msix_entries) {
+                        ql_dbg(ql_dbg_tgt, vha, 0xffff,
+                            "%s: host%ld : vector %d cpu %d\n",
+                            __func__, vha->host_no,
+                            ha->msix_entries[rspq_ent].vector,
+                            ha->msix_entries[rspq_ent].cpuid);
+
+                        ha->tgt.rspq_vector_cpuid =
+                            ha->msix_entries[rspq_ent].cpuid;
+                }
+
                 set_bit(ISP_ABORT_NEEDED, &base_vha->dpc_flags);
                 qla2xxx_wake_dpc(base_vha);
                 qla2x00_wait_for_hba_online(base_vha);