PCI AER: support Multiple Error Received and no error source id

Based on PCI Express AER specs, a root port might receive multiple
TLP errors while it could only save a correctable error source id
and an uncorrectable error source id at the same time. In addition,
some root port hardware might be unable to provide a correct source
id, i.e., the source id, or the bus id part of the source id provided
by root port might be equal to 0.

The patchset implements the support in kernel by searching the device
tree under the root port.

Patch 1 changes parameter cb of function pci_walk_bus to return a value.
When cb return non-zero, pci_walk_bus stops more searching on the
device tree.

Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 24 insertions, 14 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c
index 9a2a6e32f00f..0e8db6771252 100644
--- a/arch/powerpc/platforms/pseries/eeh_driver.c
+++ b/arch/powerpc/platforms/pseries/eeh_driver.c
@@ -122,7 +122,7 @@ static void eeh_enable_irq(struct pci_dev *dev)
  * passed back in "userdata".
  */
 
-static void eeh_report_error(struct pci_dev *dev, void *userdata)
+static int eeh_report_error(struct pci_dev *dev, void *userdata)
 {
         enum pci_ers_result rc, *res = userdata;
         struct pci_driver *driver = dev->driver;
@@ -130,19 +130,21 @@ static void eeh_report_error(struct pci_dev *dev, void *userdata)
         dev->error_state = pci_channel_io_frozen;
 
         if (!driver)
-                return;
+                return 0;
 
         eeh_disable_irq(dev);
 
         if (!driver->err_handler ||
             !driver->err_handler->error_detected)
-                return;
+                return 0;
 
         rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen);
 
         /* A driver that needs a reset trumps all others */
         if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
         if (*res == PCI_ERS_RESULT_NONE) *res = rc;
+
+        return 0;
 }
 
 /**
@@ -153,7 +155,7 @@ static void eeh_report_error(struct pci_dev *dev, void *userdata)
  * Cumulative response passed back in "userdata".
  */
 
-static void eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata)
+static int eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata)
 {
         enum pci_ers_result rc, *res = userdata;
         struct pci_driver *driver = dev->driver;
@@ -161,26 +163,28 @@ static void eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata)
         if (!driver ||
             !driver->err_handler ||
             !driver->err_handler->mmio_enabled)
-                return;
+                return 0;
 
         rc = driver->err_handler->mmio_enabled (dev);
 
         /* A driver that needs a reset trumps all others */
         if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
         if (*res == PCI_ERS_RESULT_NONE) *res = rc;
+
+        return 0;
 }
 
 /**
  * eeh_report_reset - tell device that slot has been reset
  */
 
-static void eeh_report_reset(struct pci_dev *dev, void *userdata)
+static int eeh_report_reset(struct pci_dev *dev, void *userdata)
 {
         enum pci_ers_result rc, *res = userdata;
         struct pci_driver *driver = dev->driver;
 
         if (!driver)
-                return;
+                return 0;
 
         dev->error_state = pci_channel_io_normal;
 
@@ -188,35 +192,39 @@ static void eeh_report_reset(struct pci_dev *dev, void *userdata)
 
         if (!driver->err_handler ||
             !driver->err_handler->slot_reset)
-                return;
+                return 0;
 
         rc = driver->err_handler->slot_reset(dev);
         if ((*res == PCI_ERS_RESULT_NONE) ||
             (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc;
         if (*res == PCI_ERS_RESULT_DISCONNECT &&
              rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
+
+        return 0;
 }
 
 /**
  * eeh_report_resume - tell device to resume normal operations
  */
 
-static void eeh_report_resume(struct pci_dev *dev, void *userdata)
+static int eeh_report_resume(struct pci_dev *dev, void *userdata)
 {
         struct pci_driver *driver = dev->driver;
 
         dev->error_state = pci_channel_io_normal;
 
         if (!driver)
-                return;
+                return 0;
 
         eeh_enable_irq(dev);
 
         if (!driver->err_handler ||
             !driver->err_handler->resume)
-                return;
+                return 0;
 
         driver->err_handler->resume(dev);
+
+        return 0;
 }
 
 /**
@@ -226,22 +234,24 @@ static void eeh_report_resume(struct pci_dev *dev, void *userdata)
  * dead, and that no further recovery attempts will be made on it.
  */
 
-static void eeh_report_failure(struct pci_dev *dev, void *userdata)
+static int eeh_report_failure(struct pci_dev *dev, void *userdata)
 {
         struct pci_driver *driver = dev->driver;
 
         dev->error_state = pci_channel_io_perm_failure;
 
         if (!driver)
-                return;
+                return 0;
 
         eeh_disable_irq(dev);
 
         if (!driver->err_handler ||
             !driver->err_handler->error_detected)
-                return;
+                return 0;
 
         driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
+
+        return 0;
 }
 
 /* ------------------------------------------------------- */