From linas@austin.ibm.com Wed Nov 16 15:00:59 2005 Date: Wed, 16 Nov 2005 17:10:41 -0600 To: Greg KH Cc: Paul Mackerras Subject: [PATCH 1/7] PCI Error Recovery: header file patch Message-ID: <20051116231041.GA16057@austin.ibm.com> Content-Disposition: inline From: linas 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 Signed-off-by: Greg Kroah-Hartman -- --- include/linux/pci.h | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) --- gregkh-2.6.orig/include/linux/pci.h +++ gregkh-2.6/include/linux/pci.h @@ -78,6 +78,23 @@ typedef int __bitwise pci_power_t; #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 @@ struct pci_dev { 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 @@ struct pci_dynids { 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 @@ struct pci_driver { 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; };