powerpc/eeh: Only disable/enable LSI interrupts in EEH

The EEH code disables and enables interrupts during the
device recovery process.  This is unnecessary for MSI
and MSI-X interrupts because they are effectively disabled
by the DMA Stopped state when an EEH error occurs.  The
current code is also incorrect for MSI-X interrupts.  It
doesn't take into account that MSI-X interrupts are tracked
in a different way than LSI/MSI interrupts.  This patch
ensures only LSI interrupts are disabled/enabled.

Signed-off-by: Mike Mason <mmlnx@us.ibm.com>
Acked-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 45 insertions, 23 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c
index 0ad56ff7b4a0..380420f8c400 100644
--- a/arch/powerpc/platforms/pseries/eeh_driver.c
+++ b/arch/powerpc/platforms/pseries/eeh_driver.c
@@ -79,6 +79,40 @@ static int irq_in_use(unsigned int irq)
         return rc;
 }
 
+/**
+ * eeh_disable_irq - disable interrupt for the recovering device
+ */
+static void eeh_disable_irq(struct pci_dev *dev)
+{
+        struct device_node *dn = pci_device_to_OF_node(dev);
+
+        /* Don't disable MSI and MSI-X interrupts. They are
+         * effectively disabled by the DMA Stopped state
+         * when an EEH error occurs.
+        */
+        if (dev->msi_enabled || dev->msix_enabled)
+                return;
+
+        if (!irq_in_use(dev->irq))
+                return;
+
+        PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
+        disable_irq_nosync(dev->irq);
+}
+
+/**
+ * eeh_enable_irq - enable interrupt for the recovering device
+ */
+static void eeh_enable_irq(struct pci_dev *dev)
+{
+        struct device_node *dn = pci_device_to_OF_node(dev);
+
+        if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
+                PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
+                enable_irq(dev->irq);
+        }
+}
+
 /* ------------------------------------------------------- */
 /**
  * eeh_report_error - report pci error to each device driver
@@ -98,11 +132,8 @@ static void eeh_report_error(struct pci_dev *dev, void *userdata)
         if (!driver)
                 return;
 
-        if (irq_in_use (dev->irq)) {
-                struct device_node *dn = pci_device_to_OF_node(dev);
-                PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
-                disable_irq_nosync(dev->irq);
-        }
+        eeh_disable_irq(dev);
+
         if (!driver->err_handler ||
             !driver->err_handler->error_detected)
                 return;
@@ -147,15 +178,12 @@ static void eeh_report_reset(struct pci_dev *dev, void *userdata)
 {
         enum pci_ers_result rc, *res = userdata;
         struct pci_driver *driver = dev->driver;
-        struct device_node *dn = pci_device_to_OF_node(dev);
 
         if (!driver)
                 return;
 
-        if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
-                PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
-                enable_irq(dev->irq);
-        }
+        eeh_enable_irq(dev);
+
         if (!driver->err_handler ||
             !driver->err_handler->slot_reset)
                 return;
@@ -174,17 +202,14 @@ static void eeh_report_reset(struct pci_dev *dev, void *userdata)
 static void eeh_report_resume(struct pci_dev *dev, void *userdata)
 {
         struct pci_driver *driver = dev->driver;
-        struct device_node *dn = pci_device_to_OF_node(dev);
 
         dev->error_state = pci_channel_io_normal;
 
         if (!driver)
                 return;
 
-        if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
-                PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
-                enable_irq(dev->irq);
-        }
+        eeh_enable_irq(dev);
+
         if (!driver->err_handler ||
             !driver->err_handler->resume)
                 return;
@@ -208,15 +233,12 @@ static void eeh_report_failure(struct pci_dev *dev, void *userdata)
         if (!driver)
                 return;
 
-        if (irq_in_use (dev->irq)) {
-                struct device_node *dn = pci_device_to_OF_node(dev);
-                PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
-                disable_irq_nosync(dev->irq);
-        }
-        if (!driver->err_handler)
-                return;
-        if (!driver->err_handler->error_detected)
+        eeh_disable_irq(dev);
+
+        if (!driver->err_handler ||
+            !driver->err_handler->error_detected)
                 return;
+
         driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
 }