---

yaml
---
r: 330335
b: refs/heads/master
c: feadf7c
h: refs/heads/master
i:
  330333: 7aeb990
  330331: 6f15251
  330327: d8c2bc1
  330319: 844cd0e
  330303: 90a4adf
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8e9f69371536981a2a8c9ee4a49dbe3aa4946df4
+refs/heads/master: feadf7c0a1a7c08c74bebb4a13b755f8c40e3bbc

trunk/arch/powerpc/platforms/pseries/eeh_driver.c

@@ -25,6 +25,7 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/module.h>
 #include <linux/pci.h>
 #include <asm/eeh.h>
 #include <asm/eeh_event.h>
@@ -47,6 +48,41 @@ static inline const char *eeh_pcid_name(struct pci_dev *pdev)
 	return "";
 }
 
+/**
+ * eeh_pcid_get - Get the PCI device driver
+ * @pdev: PCI device
+ *
+ * The function is used to retrieve the PCI device driver for
+ * the indicated PCI device. Besides, we will increase the reference
+ * of the PCI device driver to prevent that being unloaded on
+ * the fly. Otherwise, kernel crash would be seen.
+ */
+static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
+{
+	if (!pdev || !pdev->driver)
+		return NULL;
+
+	if (!try_module_get(pdev->driver->driver.owner))
+		return NULL;
+
+	return pdev->driver;
+}
+
+/**
+ * eeh_pcid_put - Dereference on the PCI device driver
+ * @pdev: PCI device
+ *
+ * The function is called to do dereference on the PCI device
+ * driver of the indicated PCI device.
+ */
+static inline void eeh_pcid_put(struct pci_dev *pdev)
+{
+	if (!pdev || !pdev->driver)
+		return;
+
+	module_put(pdev->driver->driver.owner);
+}
+
 #if 0
 static void print_device_node_tree(struct pci_dn *pdn, int dent)
 {
@@ -128,30 +164,32 @@ static void *eeh_report_error(void *data, void *userdata)
 	struct eeh_dev *edev = (struct eeh_dev *)data;
 	struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 	enum pci_ers_result rc, *res = userdata;
-	struct pci_driver *driver = dev->driver;
+	struct pci_driver *driver;
 
 	/* We might not have the associated PCI device,
 	 * then we should continue for next one.
 	 */
 	if (!dev) return NULL;
-
 	dev->error_state = pci_channel_io_frozen;
 
-	if (!driver)
-		return NULL;
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
 
 	eeh_disable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->error_detected)
+	    !driver->err_handler->error_detected) {
+		eeh_pcid_put(dev);
 		return NULL;
+	}
 
 	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;
 
+	eeh_pcid_put(dev);
 	return NULL;
 }
 
@@ -171,19 +209,22 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata)
 	enum pci_ers_result rc, *res = userdata;
 	struct pci_driver *driver;
 
-	if (!dev) return NULL;
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
 
-	if (!(driver = dev->driver) ||
-	    !driver->err_handler ||
-	    !driver->err_handler->mmio_enabled)
+	if (!driver->err_handler ||
+	    !driver->err_handler->mmio_enabled) {
+		eeh_pcid_put(dev);
 		return NULL;
+	}
 
 	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;
 
+	eeh_pcid_put(dev);
 	return NULL;
 }
 
@@ -204,23 +245,27 @@ static void *eeh_report_reset(void *data, void *userdata)
 	enum pci_ers_result rc, *res = userdata;
 	struct pci_driver *driver;
 
-	if (!dev || !(driver = dev->driver))
-		return NULL;
-
+	if (!dev) return NULL;
 	dev->error_state = pci_channel_io_normal;
 
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
+
 	eeh_enable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->slot_reset)
+	    !driver->err_handler->slot_reset) {
+		eeh_pcid_put(dev);
 		return NULL;
+	}
 
 	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;
 
+	eeh_pcid_put(dev);
 	return NULL;
 }
 
@@ -240,20 +285,22 @@ static void *eeh_report_resume(void *data, void *userdata)
 	struct pci_driver *driver;
 
 	if (!dev) return NULL;
-
 	dev->error_state = pci_channel_io_normal;
 
-	if (!(driver = dev->driver))
-		return NULL;
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
 
 	eeh_enable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->resume)
+	    !driver->err_handler->resume) {
+		eeh_pcid_put(dev);
 		return NULL;
+	}
 
 	driver->err_handler->resume(dev);
 
+	eeh_pcid_put(dev);
 	return NULL;
 }
 
@@ -272,20 +319,22 @@ static void *eeh_report_failure(void *data, void *userdata)
 	struct pci_driver *driver;
 
 	if (!dev) return NULL;
-
 	dev->error_state = pci_channel_io_perm_failure;
 
-	if (!(driver = dev->driver))
-		return NULL;
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
 
 	eeh_disable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->error_detected)
+	    !driver->err_handler->error_detected) {
+		eeh_pcid_put(dev);
 		return NULL;
+	}
 
 	driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
 
+	eeh_pcid_put(dev);
 	return NULL;
 }