[PATCH] PCI Error Recovery: header file patch
Various PCI bus errors can be signaled by newer PCI controllers.
Recovering from those errors requires an infrastructure to notify
affected device drivers of the error, and a way of walking through a
reset sequence. This patch adds a set of callbacks to be used by error
recovery routines to notify device drivers of the various stages of
recovery.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d0e0039..0a44072 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -78,6 +78,23 @@
#define PCI_UNKNOWN ((pci_power_t __force) 5)
#define PCI_POWER_ERROR ((pci_power_t __force) -1)
+/** The pci_channel state describes connectivity between the CPU and
+ * the pci device. If some PCI bus between here and the pci device
+ * has crashed or locked up, this info is reflected here.
+ */
+typedef unsigned int __bitwise pci_channel_state_t;
+
+enum pci_channel_state {
+ /* I/O channel is in normal state */
+ pci_channel_io_normal = (__force pci_channel_state_t) 1,
+
+ /* I/O to channel is blocked */
+ pci_channel_io_frozen = (__force pci_channel_state_t) 2,
+
+ /* PCI card is dead */
+ pci_channel_io_perm_failure = (__force pci_channel_state_t) 3,
+};
+
/*
* The pci_dev structure is used to describe PCI devices.
*/
@@ -111,6 +128,7 @@
this is D0-D3, D0 being fully functional,
and D3 being off. */
+ pci_channel_state_t error_state; /* current connectivity state */
struct device dev; /* Generic device interface */
/* device is compatible with these IDs */
@@ -233,6 +251,54 @@
unsigned int use_driver_data:1; /* pci_driver->driver_data is used */
};
+/* ---------------------------------------------------------------- */
+/** PCI Error Recovery System (PCI-ERS). If a PCI device driver provides
+ * a set fof callbacks in struct pci_error_handlers, then that device driver
+ * will be notified of PCI bus errors, and will be driven to recovery
+ * when an error occurs.
+ */
+
+typedef unsigned int __bitwise pci_ers_result_t;
+
+enum pci_ers_result {
+ /* no result/none/not supported in device driver */
+ PCI_ERS_RESULT_NONE = (__force pci_ers_result_t) 1,
+
+ /* Device driver can recover without slot reset */
+ PCI_ERS_RESULT_CAN_RECOVER = (__force pci_ers_result_t) 2,
+
+ /* Device driver wants slot to be reset. */
+ PCI_ERS_RESULT_NEED_RESET = (__force pci_ers_result_t) 3,
+
+ /* Device has completely failed, is unrecoverable */
+ PCI_ERS_RESULT_DISCONNECT = (__force pci_ers_result_t) 4,
+
+ /* Device driver is fully recovered and operational */
+ PCI_ERS_RESULT_RECOVERED = (__force pci_ers_result_t) 5,
+};
+
+/* PCI bus error event callbacks */
+struct pci_error_handlers
+{
+ /* PCI bus error detected on this device */
+ pci_ers_result_t (*error_detected)(struct pci_dev *dev,
+ enum pci_channel_state error);
+
+ /* MMIO has been re-enabled, but not DMA */
+ pci_ers_result_t (*mmio_enabled)(struct pci_dev *dev);
+
+ /* PCI Express link has been reset */
+ pci_ers_result_t (*link_reset)(struct pci_dev *dev);
+
+ /* PCI slot has been reset */
+ pci_ers_result_t (*slot_reset)(struct pci_dev *dev);
+
+ /* Device driver may resume normal operations */
+ void (*resume)(struct pci_dev *dev);
+};
+
+/* ---------------------------------------------------------------- */
+
struct module;
struct pci_driver {
struct list_head node;
@@ -245,6 +311,7 @@
int (*enable_wake) (struct pci_dev *dev, pci_power_t state, int enable); /* Enable wake event */
void (*shutdown) (struct pci_dev *dev);
+ struct pci_error_handlers *err_handler;
struct device_driver driver;
struct pci_dynids dynids;
};