mpt3sas: Added smp_affinity_enable module parameter.

Module parameter to enable/disable configuring affinity hint for msix
vector.  SMP affinity feature can be enabled/disabled by setting module
parameter "smp_affinity_enable" to 1/0.  By default this feature is
enabled. (smp_affinity_enable = 1 enabled).

Signed-off-by: Suganath prabu Subramani <suganath-prabu.subramani@avagotech.com>
Signed-off-by: Chaitra P B <chaitra.basappa@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 31838d9ad39bf105985256e8789d46ee64dc752e..582ba4b8033e6d5b017eb9ca27107c5777bd025c 100644 (file)
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -83,6 +83,10 @@ static int msix_disable = -1;
 module_param(msix_disable, int, 0);
 MODULE_PARM_DESC(msix_disable, " disable msix routed interrupts (default=0)");
 
+static int smp_affinity_enable = 1;
+module_param(smp_affinity_enable, int, S_IRUGO);
+MODULE_PARM_DESC(smp_affinity_enable, "SMP affinity feature enable/disbale Default: enable(1)");
+
 static int max_msix_vectors = -1;
 module_param(max_msix_vectors, int, 0);
 MODULE_PARM_DESC(max_msix_vectors,
@@ -1812,8 +1816,10 @@ _base_free_irq(struct MPT3SAS_ADAPTER *ioc)
 
        list_for_each_entry_safe(reply_q, next, &ioc->reply_queue_list, list) {
                list_del(&reply_q->list);
-               irq_set_affinity_hint(reply_q->vector, NULL);
-               free_cpumask_var(reply_q->affinity_hint);
+               if (smp_affinity_enable) {
+                       irq_set_affinity_hint(reply_q->vector, NULL);
+                       free_cpumask_var(reply_q->affinity_hint);
+               }
                synchronize_irq(reply_q->vector);
                free_irq(reply_q->vector, reply_q);
                kfree(reply_q);
@@ -1844,9 +1850,13 @@ _base_request_irq(struct MPT3SAS_ADAPTER *ioc, u8 index, u32 vector)
        reply_q->msix_index = index;
        reply_q->vector = vector;
 
-       if (!alloc_cpumask_var(&reply_q->affinity_hint, GFP_KERNEL))
-               return -ENOMEM;
-       cpumask_clear(reply_q->affinity_hint);
+       if (smp_affinity_enable) {
+               if (!zalloc_cpumask_var(&reply_q->affinity_hint, GFP_KERNEL)) {
+                       kfree(reply_q);
+                       return -ENOMEM;
+               }
+               cpumask_clear(reply_q->affinity_hint);
+       }
 
        atomic_set(&reply_q->busy, 0);
        if (ioc->msix_enable)
@@ -1861,6 +1871,7 @@ _base_request_irq(struct MPT3SAS_ADAPTER *ioc, u8 index, u32 vector)
                pr_err(MPT3SAS_FMT "unable to allocate interrupt %d!\n",
                    reply_q->name, vector);
                kfree(reply_q);
+               free_cpumask_var(reply_q->affinity_hint);
                return -EBUSY;
        }
 
@@ -1909,16 +1920,17 @@ _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc)
 
                for (i = 0 ; i < group ; i++) {
                        ioc->cpu_msix_table[cpu] = index;
-                       cpumask_or(reply_q->affinity_hint,
+                       if (smp_affinity_enable)
+                               cpumask_or(reply_q->affinity_hint,
                                   reply_q->affinity_hint, get_cpu_mask(cpu));
                        cpu = cpumask_next(cpu, cpu_online_mask);
                }
-
-               if (irq_set_affinity_hint(reply_q->vector,
+               if (smp_affinity_enable)
+                       if (irq_set_affinity_hint(reply_q->vector,
                                           reply_q->affinity_hint))
-                       dinitprintk(ioc, pr_info(MPT3SAS_FMT
-                           "error setting affinity hint for irq vector %d\n",
-                           ioc->name, reply_q->vector));
+                               dinitprintk(ioc, pr_info(MPT3SAS_FMT
+                                "Err setting affinity hint to irq vector %d\n",
+                                ioc->name, reply_q->vector));
                index++;
        }
 }
@@ -1976,6 +1988,9 @@ _base_enable_msix(struct MPT3SAS_ADAPTER *ioc)
        } else if (max_msix_vectors == 0)
                goto try_ioapic;
 
+       if (ioc->msix_vector_count < ioc->cpu_count)
+               smp_affinity_enable = 0;
+
        entries = kcalloc(ioc->reply_queue_count, sizeof(struct msix_entry),
            GFP_KERNEL);
        if (!entries) {