[PATCH 7/22] PCI Error Recovery: header file patch

linas
2005-10-06T23:32:15Z

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>

--
include/linux/pci.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 49 insertions(+)

Index: linux-2.6.14-rc2-git6/include/linux/pci.h
===================================================================
--- linux-2.6.14-rc2-git6.orig/include/linux/pci.h 2005-10-06 17:50:29.442032212 -0500
+++ linux-2.6.14-rc2-git6/include/linux/pci.h 2005-10-06 17:52:50.634221570 -0500
@@ -78,6 +78,16 @@
#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.
+ */
+enum pci_channel_state {
+ pci_channel_io_normal = 0, /* I/O channel is in normal state */
+ pci_channel_io_frozen = 1, /* I/O to channel is blocked */
+ pci_channel_io_perm_failure, /* PCI card is dead */
+};
+
/*
* The pci_dev structure is used to describe PCI devices.
*/
@@ -110,6 +120,7 @@
this is D0-D3, D0 being fully functional,
and D3 being off. */

+ enum pci_channel_state error_state; /* current connectivity state */
struct device dev; /* Generic device interface */

/* device is compatible with these IDs */
@@ -231,6 +242,43 @@
unsigned int use_driver_data:1; /* pci_driver->driver_data is used */
};

+/* ---------------------------------------------------------------- */
+/** PCI error recovery infrastructure. 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.
+ */
+
+enum pcierr_result {
+ PCIERR_RESULT_NONE=0, /* no result/none/not supported in device driver */
+ PCIERR_RESULT_CAN_RECOVER=1, /* Device driver can recover without slot reset */
+ PCIERR_RESULT_NEED_RESET, /* Device driver wants slot to be reset. */
+ PCIERR_RESULT_DISCONNECT, /* Device has completely failed, is unrecoverable */
+ PCIERR_RESULT_RECOVERED, /* Device driver is fully recovered and operational */
+};
+
+/* PCI bus error event callbacks */
+struct pci_error_handlers
+{
+ /* PCI bus error detected on this device */
+ int (*error_detected)(struct pci_dev *dev,
+ enum pci_channel_state error);
+
+ /* MMIO has been re-enabled, but not DMA */
+ int (*mmio_enabled)(struct pci_dev *dev);
+
+ /* PCI Express link has been reset */
+ int (*link_reset)(struct pci_dev *dev);
+
+ /* PCI slot has been reset */
+ int (*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;
@@ -244,6 +292,7 @@
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;
};