[SCSI] megaraid_sas: Add MSI-X support and msix_disable module parameter

This patch adds MSI-X support and 'msix_disable' module parameter to
the megaraid_sas driver.

Signed-off-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 37 insertions, 7 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 224ec31e5c97..ff9845c72a67 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1335,6 +1335,9 @@ struct megasas_instance {
 
         struct timer_list io_completion_timer;
         struct list_head internal_reset_pending_q;
+
+        u8      msi_flag;
+        struct msix_entry msixentry;
 };
 
 enum {
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index dab29db3b48e..2318183f9a67 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -72,6 +72,10 @@ module_param_named(max_sectors, max_sectors, int, 0);
 MODULE_PARM_DESC(max_sectors,
         "Maximum number of sectors per IO command");
 
+static int msix_disable;
+module_param(msix_disable, int, S_IRUGO);
+MODULE_PARM_DESC(msix_disable, "Disable MSI-X interrupt handling. Default: 0");
+
 MODULE_LICENSE("GPL");
 MODULE_VERSION(MEGASAS_VERSION);
 MODULE_AUTHOR("megaraidlinux@lsi.com");
@@ -3863,10 +3867,20 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
         if (megasas_init_mfi(instance))
                 goto fail_init_mfi;
 
+        /* Try to enable MSI-X */
+        if ((instance->pdev->device != PCI_DEVICE_ID_LSI_SAS1078R) &&
+            (instance->pdev->device != PCI_DEVICE_ID_LSI_SAS1078DE) &&
+            (instance->pdev->device != PCI_DEVICE_ID_LSI_VERDE_ZCR) &&
+            !msix_disable && !pci_enable_msix(instance->pdev,
+                                              &instance->msixentry, 1))
+                instance->msi_flag = 1;
+
         /*
          * Register IRQ
          */
-        if (request_irq(pdev->irq, megasas_isr, IRQF_SHARED, "megasas", instance)) {
+        if (request_irq(instance->msi_flag ? instance->msixentry.vector :
+                        pdev->irq, megasas_isr,
+                        IRQF_SHARED, "megasas", instance)) {
                 printk(KERN_DEBUG "megasas: Failed to register IRQ\n");
                 goto fail_irq;
         }
@@ -3911,8 +3925,10 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         pci_set_drvdata(pdev, NULL);
         instance->instancet->disable_intr(instance->reg_set);
-        free_irq(instance->pdev->irq, instance);
-
+        free_irq(instance->msi_flag ? instance->msixentry.vector :
+                 instance->pdev->irq, instance);
+        if (instance->msi_flag)
+                pci_disable_msix(instance->pdev);
         megasas_release_mfi(instance);
 
       fail_irq:
@@ -4053,7 +4069,10 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state)
 
         pci_set_drvdata(instance->pdev, instance);
         instance->instancet->disable_intr(instance->reg_set);
-        free_irq(instance->pdev->irq, instance);
+        free_irq(instance->msi_flag ? instance->msixentry.vector :
+                 instance->pdev->irq, instance);
+        if (instance->msi_flag)
+                pci_disable_msix(instance->pdev);
 
         pci_save_state(pdev);
         pci_disable_device(pdev);
@@ -4116,11 +4135,16 @@ megasas_resume(struct pci_dev *pdev)
         tasklet_init(&instance->isr_tasklet, megasas_complete_cmd_dpc,
                         (unsigned long)instance);
 
+        /* Now re-enable MSI-X */
+        if (instance->msi_flag)
+                pci_enable_msix(instance->pdev, &instance->msixentry, 1);
+
         /*
          * Register IRQ
          */
-        if (request_irq(pdev->irq, megasas_isr, IRQF_SHARED,
-                "megasas", instance)) {
+        if (request_irq(instance->msi_flag ? instance->msixentry.vector :
+                        pdev->irq, megasas_isr,
+                        IRQF_SHARED, "megasas", instance)) {
                 printk(KERN_ERR "megasas: Failed to register IRQ\n");
                 goto fail_irq;
         }
@@ -4218,7 +4242,10 @@ static void __devexit megasas_detach_one(struct pci_dev *pdev)
 
         instance->instancet->disable_intr(instance->reg_set);
 
-        free_irq(instance->pdev->irq, instance);
+        free_irq(instance->msi_flag ? instance->msixentry.vector :
+                 instance->pdev->irq, instance);
+        if (instance->msi_flag)
+                pci_disable_msix(instance->pdev);
 
         megasas_release_mfi(instance);