scsi: hpsa: fix selection of reply queue

Since commit 84676c1f21e8 ("genirq/affinity: assign vectors to all
possible CPUs") we could end up with an MSI-X vector that did not have
any online CPUs mapped. This would lead to I/O hangs since there was no
CPU to receive the completion.

Retrieve IRQ affinity information using pci_irq_get_affinity() and use
this mapping to choose a reply queue.

[mkp: tweaked commit desc]

Cc: Hannes Reinecke <hare@suse.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Artem Bityutskiy <artem.bityutskiy@intel.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Fixes: 84676c1f21e8 ("genirq/affinity: assign vectors to all possible CPUs")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Don Brace <don.brace@microsemi.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 55 insertions, 19 deletions

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 87b260e403ec..31423b6dc26d 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -1045,11 +1045,7 @@ static void set_performant_mode(struct ctlr_info *h, struct CommandList *c,
                 c->busaddr |= 1 | (h->blockFetchTable[c->Header.SGList] << 1);
                 if (unlikely(!h->msix_vectors))
                         return;
-                if (likely(reply_queue == DEFAULT_REPLY_QUEUE))
-                        c->Header.ReplyQueue =
-                                raw_smp_processor_id() % h->nreply_queues;
-                else
-                        c->Header.ReplyQueue = reply_queue % h->nreply_queues;
+                c->Header.ReplyQueue = reply_queue;
         }
 }
 
@@ -1063,10 +1059,7 @@ static void set_ioaccel1_performant_mode(struct ctlr_info *h,
          * Tell the controller to post the reply to the queue for this
          * processor.  This seems to give the best I/O throughput.
          */
-        if (likely(reply_queue == DEFAULT_REPLY_QUEUE))
-                cp->ReplyQueue = smp_processor_id() % h->nreply_queues;
-        else
-                cp->ReplyQueue = reply_queue % h->nreply_queues;
+        cp->ReplyQueue = reply_queue;
         /*
          * Set the bits in the address sent down to include:
          *  - performant mode bit (bit 0)
@@ -1087,10 +1080,7 @@ static void set_ioaccel2_tmf_performant_mode(struct ctlr_info *h,
         /* Tell the controller to post the reply to the queue for this
          * processor.  This seems to give the best I/O throughput.
          */
-        if (likely(reply_queue == DEFAULT_REPLY_QUEUE))
-                cp->reply_queue = smp_processor_id() % h->nreply_queues;
-        else
-                cp->reply_queue = reply_queue % h->nreply_queues;
+        cp->reply_queue = reply_queue;
         /* Set the bits in the address sent down to include:
          *  - performant mode bit not used in ioaccel mode 2
          *  - pull count (bits 0-3)
@@ -1109,10 +1099,7 @@ static void set_ioaccel2_performant_mode(struct ctlr_info *h,
          * Tell the controller to post the reply to the queue for this
          * processor.  This seems to give the best I/O throughput.
          */
-        if (likely(reply_queue == DEFAULT_REPLY_QUEUE))
-                cp->reply_queue = smp_processor_id() % h->nreply_queues;
-        else
-                cp->reply_queue = reply_queue % h->nreply_queues;
+        cp->reply_queue = reply_queue;
         /*
          * Set the bits in the address sent down to include:
          *  - performant mode bit not used in ioaccel mode 2
@@ -1157,6 +1144,8 @@ static void __enqueue_cmd_and_start_io(struct ctlr_info *h,
 {
         dial_down_lockup_detection_during_fw_flash(h, c);
         atomic_inc(&h->commands_outstanding);
+
+        reply_queue = h->reply_map[raw_smp_processor_id()];
         switch (c->cmd_type) {
         case CMD_IOACCEL1:
                 set_ioaccel1_performant_mode(h, c, reply_queue);
@@ -7376,6 +7365,26 @@ static void hpsa_disable_interrupt_mode(struct ctlr_info *h)
         h->msix_vectors = 0;
 }
 
+static void hpsa_setup_reply_map(struct ctlr_info *h)
+{
+        const struct cpumask *mask;
+        unsigned int queue, cpu;
+
+        for (queue = 0; queue < h->msix_vectors; queue++) {
+                mask = pci_irq_get_affinity(h->pdev, queue);
+                if (!mask)
+                        goto fallback;
+
+                for_each_cpu(cpu, mask)
+                        h->reply_map[cpu] = queue;
+        }
+        return;
+
+fallback:
+        for_each_possible_cpu(cpu)
+                h->reply_map[cpu] = 0;
+}
+
 /* If MSI/MSI-X is supported by the kernel we will try to enable it on
  * controllers that are capable. If not, we use legacy INTx mode.
  */
@@ -7771,6 +7780,10 @@ static int hpsa_pci_init(struct ctlr_info *h)
         err = hpsa_interrupt_mode(h);
         if (err)
                 goto clean1;
+
+        /* setup mapping between CPU and reply queue */
+        hpsa_setup_reply_map(h);
+
         err = hpsa_pci_find_memory_BAR(h->pdev, &h->paddr);
         if (err)
                 goto clean2;    /* intmode+region, pci */
@@ -8480,6 +8493,28 @@ static struct workqueue_struct *hpsa_create_controller_wq(struct ctlr_info *h,
         return wq;
 }
 
+static void hpda_free_ctlr_info(struct ctlr_info *h)
+{
+        kfree(h->reply_map);
+        kfree(h);
+}
+
+static struct ctlr_info *hpda_alloc_ctlr_info(void)
+{
+        struct ctlr_info *h;
+
+        h = kzalloc(sizeof(*h), GFP_KERNEL);
+        if (!h)
+                return NULL;
+
+        h->reply_map = kzalloc(sizeof(*h->reply_map) * nr_cpu_ids, GFP_KERNEL);
+        if (!h->reply_map) {
+                kfree(h);
+                return NULL;
+        }
+        return h;
+}
+
 static int hpsa_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
         int dac, rc;
@@ -8517,7 +8552,7 @@ reinit_after_soft_reset:
          * the driver.  See comments in hpsa.h for more info.
          */
         BUILD_BUG_ON(sizeof(struct CommandList) % COMMANDLIST_ALIGNMENT);
-        h = kzalloc(sizeof(*h), GFP_KERNEL);
+        h = hpda_alloc_ctlr_info();
         if (!h) {
                 dev_err(&pdev->dev, "Failed to allocate controller head\n");
                 return -ENOMEM;
@@ -8916,7 +8951,7 @@ static void hpsa_remove_one(struct pci_dev *pdev)
         h->lockup_detected = NULL;                      /* init_one 2 */
         /* (void) pci_disable_pcie_error_reporting(pdev); */    /* init_one 1 */
 
-        kfree(h);                                       /* init_one 1 */
+        hpda_free_ctlr_info(h);                         /* init_one 1 */
 }
 
 static int hpsa_suspend(__attribute__((unused)) struct pci_dev *pdev,
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 018f980a701c..fb9f5e7f8209 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -158,6 +158,7 @@ struct bmic_controller_parameters {
 #pragma pack()
 
 struct ctlr_info {
+        unsigned int *reply_map;
         int     ctlr;
         char    devname[8];
         char    *product_name;