IB/hfi1: Add irq affinity notification handler

This patch adds an irq affinity notification handler.
When a user changes interrupt affinity settings for an sdma engine,
the driver needs to make changes to its internal sde structures and
also update the affinity_hint.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Reviewed-by: Jianxin Xiong <jianxin.xiong@intel.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/hfi1/affinity.c b/drivers/infiniband/hw/hfi1/affinity.c
index 17c805a..a26a9a0 100644 (file)
--- a/drivers/infiniband/hw/hfi1/affinity.c
+++ b/drivers/infiniband/hw/hfi1/affinity.c
@@ -47,6 +47,7 @@
 #include <linux/topology.h>
 #include <linux/cpumask.h>
 #include <linux/module.h>
+#include <linux/interrupt.h>
 
 #include "hfi.h"
 #include "affinity.h"
@@ -308,6 +309,101 @@ int hfi1_dev_affinity_init(struct hfi1_devdata *dd)
        return 0;
 }
 
+/*
+ * Function updates the irq affinity hint for msix after it has been changed
+ * by the user using the /proc/irq interface. This function only accepts
+ * one cpu in the mask.
+ */
+static void hfi1_update_sdma_affinity(struct hfi1_msix_entry *msix, int cpu)
+{
+       struct sdma_engine *sde = msix->arg;
+       struct hfi1_devdata *dd = sde->dd;
+       struct hfi1_affinity_node *entry;
+       struct cpu_mask_set *set;
+       int i, old_cpu;
+
+       if (cpu > num_online_cpus() || cpu == sde->cpu)
+               return;
+
+       mutex_lock(&node_affinity.lock);
+       entry = node_affinity_lookup(dd->node);
+       if (!entry)
+               goto unlock;
+
+       old_cpu = sde->cpu;
+       sde->cpu = cpu;
+       cpumask_clear(&msix->mask);
+       cpumask_set_cpu(cpu, &msix->mask);
+       dd_dev_dbg(dd, "IRQ vector: %u, type %s engine %u -> cpu: %d\n",
+                  msix->msix.vector, irq_type_names[msix->type],
+                  sde->this_idx, cpu);
+       irq_set_affinity_hint(msix->msix.vector, &msix->mask);
+
+       /*
+        * Set the new cpu in the hfi1_affinity_node and clean
+        * the old cpu if it is not used by any other IRQ
+        */
+       set = &entry->def_intr;
+       cpumask_set_cpu(cpu, &set->mask);
+       cpumask_set_cpu(cpu, &set->used);
+       for (i = 0; i < dd->num_msix_entries; i++) {
+               struct hfi1_msix_entry *other_msix;
+
+               other_msix = &dd->msix_entries[i];
+               if (other_msix->type != IRQ_SDMA || other_msix == msix)
+                       continue;
+
+               if (cpumask_test_cpu(old_cpu, &other_msix->mask))
+                       goto unlock;
+       }
+       cpumask_clear_cpu(old_cpu, &set->mask);
+       cpumask_clear_cpu(old_cpu, &set->used);
+unlock:
+       mutex_unlock(&node_affinity.lock);
+}
+
+static void hfi1_irq_notifier_notify(struct irq_affinity_notify *notify,
+                                    const cpumask_t *mask)
+{
+       int cpu = cpumask_first(mask);
+       struct hfi1_msix_entry *msix = container_of(notify,
+                                                   struct hfi1_msix_entry,
+                                                   notify);
+
+       /* Only one CPU configuration supported currently */
+       hfi1_update_sdma_affinity(msix, cpu);
+}
+
+static void hfi1_irq_notifier_release(struct kref *ref)
+{
+       /*
+        * This is required by affinity notifier. We don't have anything to
+        * free here.
+        */
+}
+
+static void hfi1_setup_sdma_notifier(struct hfi1_msix_entry *msix)
+{
+       struct irq_affinity_notify *notify = &msix->notify;
+
+       notify->irq = msix->msix.vector;
+       notify->notify = hfi1_irq_notifier_notify;
+       notify->release = hfi1_irq_notifier_release;
+
+       if (irq_set_affinity_notifier(notify->irq, notify))
+               pr_err("Failed to register sdma irq affinity notifier for irq %d\n",
+                      notify->irq);
+}
+
+static void hfi1_cleanup_sdma_notifier(struct hfi1_msix_entry *msix)
+{
+       struct irq_affinity_notify *notify = &msix->notify;
+
+       if (irq_set_affinity_notifier(notify->irq, NULL))
+               pr_err("Failed to cleanup sdma irq affinity notifier for irq %d\n",
+                      notify->irq);
+}
+
 /*
  * Function sets the irq affinity for msix.
  * It *must* be called with node_affinity.lock held.
@@ -374,22 +470,17 @@ static int get_irq_affinity(struct hfi1_devdata *dd,
                cpumask_set_cpu(cpu, &set->used);
        }
 
-       switch (msix->type) {
-       case IRQ_SDMA:
-               sde->cpu = cpu;
-               break;
-       case IRQ_GENERAL:
-       case IRQ_RCVCTXT:
-       case IRQ_OTHER:
-               break;
-       }
-
        cpumask_set_cpu(cpu, &msix->mask);
        dd_dev_info(dd, "IRQ vector: %u, type %s %s -> cpu: %d\n",
                    msix->msix.vector, irq_type_names[msix->type],
                    extra, cpu);
        irq_set_affinity_hint(msix->msix.vector, &msix->mask);
 
+       if (msix->type == IRQ_SDMA) {
+               sde->cpu = cpu;
+               hfi1_setup_sdma_notifier(msix);
+       }
+
        free_cpumask_var(diff);
        return 0;
 }
@@ -417,6 +508,7 @@ void hfi1_put_irq_affinity(struct hfi1_devdata *dd,
        switch (msix->type) {
        case IRQ_SDMA:
                set = &entry->def_intr;
+               hfi1_cleanup_sdma_notifier(msix);
                break;
        case IRQ_GENERAL:
                /* Don't do accounting for general contexts */

diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index 59f69fa..7eef11b 100644 (file)
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -531,6 +531,7 @@ struct hfi1_msix_entry {
        void *arg;
        char name[MAX_NAME_SIZE];
        cpumask_t mask;
+       struct irq_affinity_notify notify;
 };
 
 /* per-SL CCA information */