/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright IBM Corp. 2004 2005
* Copyright Linas Vepstas <linas@linas.org> 2004, 2005
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/pci.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/ppc-pci.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>
#include <asm/rtas.h>
static inline const char * pcid_name (struct pci_dev *pdev)
{
if (pdev && pdev->dev.driver)
return pdev->dev.driver->name;
return "";
}
#if 0
static void print_device_node_tree(struct pci_dn *pdn, int dent)
{
int i;
struct device_node *pc;
if (!pdn)
return;
for (i = 0; i < dent; i++)
printk(" ");
printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n",
pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr,
pdn->eeh_pe_config_addr, pdn->node->full_name);
dent += 3;
pc = pdn->node->child;
while (pc) {
print_device_node_tree(PCI_DN(pc), dent);
pc = pc->sibling;
}
}
#endif
/**
* eeh_disable_irq - disable interrupt for the recovering device
*/
static void eeh_disable_irq(struct pci_dev *dev)
{
struct device_node *dn = pci_device_to_OF_node(dev);
/* Don't disable MSI and MSI-X interrupts. They are
* effectively disabled by the DMA Stopped state
* when an EEH error occurs.
*/
if (dev->msi_enabled || dev->msix_enabled)
return;
if (!irq_has_action(dev->irq))
return;
PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
/**
* eeh_enable_irq - enable interrupt for the recovering device
*/
static void eeh_enable_irq(struct pci_dev *dev)
{
struct device_node *dn = pci_device_to_OF_node(dev);
if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
enable_irq(dev->irq);
}
}
/* ------------------------------------------------------- */
/**
* eeh_report_error - report pci error to each device driver
*
* Report an EEH error to each device driver, collect up and
* merge the device driver responses. Cumulative response
* passed back in "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;
dev->error_state = pci_channel_io_frozen;
if (!driver)
return 0;
eeh_disable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->error_detected)
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;
}
/**
* eeh_report_mmio_enabled - tell drivers that MMIO has been enabled
*
* Tells each device driver that IO ports, MMIO and config space I/O
* are now enabled. Collects up and merges the device driver responses.
* Cumulative response passed back in "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;
if (!driver ||
!driver->err_handler ||
!driver->err_handler->mmio_enabled)
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 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 0;
dev->error_state = pci_channel_io_normal;
eeh_enable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->slot_reset)
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 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 0;
eeh_enable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->resume)
return 0;
driver->err_handler->resume(dev);
return 0;
}
/**
* eeh_report_failure - tell device driver that device is dead.
*
* This informs the device driver that the device is permanently
* dead, and that no further recovery attempts will be made on it.
*/
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 0;
eeh_disable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->error_detected)
return 0;
driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
return 0;
}
/* ------------------------------------------------------- */
/**
* handle_eeh_events -- reset a PCI device after hard lockup.
*
* pSeries systems will isolate a PCI slot if the PCI-Host
* bridge detects address or data parity errors, DMA's
* occurring to wild addresses (which usually happen due to
* bugs in device drivers or in PCI adapter firmware).
* Slot isolations also occur if #SERR, #PERR or other misc
* PCI-related errors are detected.
*
* Recovery process consists of unplugging the device driver
* (which generated hotplug events to userspace), then issuing
* a PCI #RST to the device, then reconfiguring the PCI config
* space for all bridges & devices under this slot, and then
* finally restarting the device drivers (which cause a second
* set of hotplug events to go out to userspace).
*/
/**
* eeh_reset_device() -- perform actual reset of a pci slot
* @bus: pointer to the pci bus structure corresponding
* to the isolated slot. A non-null value will
* cause all devices under the bus to be removed
* and then re-added.
* @pe_dn: pointer to a "Partionable Endpoint" device node.
* This is the top-level structure on which pci
* bus resets can be performed.
*/
static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
{
struct device_node *dn;
int cnt, rc;
/* pcibios will clear the counter; save the value */
cnt = pe_dn->eeh_freeze_count;
if (bus)
pcibios_remove_pci_devices(bus);
/* Reset the pci controller. (Asserts RST#; resets config space).
* Reconfigure bridges and devices. Don't try to bring the system
* up if the reset failed for some reason. */
rc = rtas_set_slot_reset(pe_dn);
if (rc)
return rc;
/* Walk over all functions on this device. */
dn = pe_dn->node;
if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
dn = dn->parent->child;
while (dn) {
struct pci_dn *ppe = PCI_DN(dn);
/* On Power4, always true because eeh_pe_config_addr=0 */
if (pe_dn->eeh_pe_config_addr == ppe->eeh_pe_config_addr) {
rtas_configure_bridge(ppe);
eeh_restore_bars(ppe);
}
dn = dn->sibling;
}
/* Give the system 5 seconds to finish running the user-space
* hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,
* this is a hack, but if we don't do this, and try to bring
* the device up before the scripts have taken it down,
* potentially weird things happen.
*/
if (bus) {
ssleep (5);
pcibios_add_pci_devices(bus);
}
pe_dn->eeh_freeze_count = cnt;
return 0;
}
/* The longest amount of time to wait for a pci device
* to come back on line, in seconds.
*/
#define MAX_WAIT_FOR_RECOVERY 150
struct pci_dn * handle_eeh_events (struct eeh_event *event)
{
struct device_node *frozen_dn;
struct pci_dn *frozen_pdn;
struct pci_bus *frozen_bus;
int rc = 0;
enum pci_ers_result result = PCI_ERS_RESULT_NONE;
const char *location, *pci_str, *drv_str;
frozen_dn = find_device_pe(event->dn);
if (!frozen_dn) {
location = of_get_property(event->dn, "ibm,loc-code", NULL);
location = location ? location : "unknown";
printk(KERN_ERR "EEH: Error: Cannot find partition endpoint "
"for location=%s pci addr=%s\n",
location, eeh_pci_name(event->dev));
return NULL;
}
frozen_bus = pcibios_find_pci_bus(frozen_dn);
location = of_get_property(frozen_dn, "ibm,loc-code", NULL);
location = location ? location : "unknown";
/* There are two different styles for coming up with the PE.
* In the old style, it was the highest EEH-capable device
* which was always an EADS pci bridge. In the new style,
* there might not be any EADS bridges, and even when there are,
* the firmware marks them as "EEH incapable". So another
* two-step is needed to find the pci bus.. */
if (!frozen_bus)
frozen_bus = pcibios_find_pci_bus (frozen_dn->parent);
if (!frozen_bus) {
printk(KERN_ERR "EEH: Cannot find PCI bus "
"for location=%s dn=%s\n",
location, frozen_dn->full_name);
return NULL;
}
frozen_pdn = PCI_DN(frozen_dn);
frozen_pdn->eeh_freeze_count++;
if (frozen_pdn->pcidev) {
pci_str = pci_name (frozen_pdn->pcidev);
drv_str = pcid_name (frozen_pdn->pcidev);
} else {
pci_str = eeh_pci_name(event->dev);
drv_str = pcid_name (event->dev);
}
if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES)
goto excess_failures;
printk(KERN_WARNING
"EEH: This PCI device has failed %d times in the last hour:\n",
frozen_pdn->eeh_freeze_count);
printk(KERN_WARNING
"EEH: location=%s driver=%s pci addr=%s\n",
location, drv_str, pci_str);
/* Walk the various device drivers attached to this slot through
* a reset sequence, giving each an opportunity to do what it needs
* to accomplish the reset. Each child gets a report of the
* status ... if any child can't handle the reset, then the entire
* slot is dlpar removed and added.
*/
pci_walk_bus(frozen_bus, eeh_report_error, &result);
/* Get the current PCI slot state. This can take a long time,
* sometimes over 3 seconds for certain systems. */
rc = eeh_wait_for_slot_status (frozen_pdn, MAX_WAIT_FOR_RECOVERY*1000);
if (rc < 0) {
printk(KERN_WARNING "EEH: Permanent failure\n");
goto hard_fail;
}
/* Since rtas may enable MMIO when posting the error log,
* don't post the error log until after all dev drivers
* have been informed.
*/
eeh_slot_error_detail(frozen_pdn, EEH_LOG_TEMP_FAILURE);
/* If all device drivers were EEH-unaware, then shut
* down all of the device drivers, and hope they
* go down willingly, without panicing the system.
*/
if (result == PCI_ERS_RESULT_NONE) {
rc = eeh_reset_device(frozen_pdn, frozen_bus);
if (rc) {
printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc);
goto hard_fail;
}
}
/* If all devices reported they can proceed, then re-enable MMIO */
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
rc = rtas_pci_enable(frozen_pdn, EEH_THAW_MMIO);
if (rc < 0)
goto hard_fail;
if (rc) {
result = PCI_ERS_RESULT_NEED_RESET;
} else {
result = PCI_ERS_RESULT_NONE;
pci_walk_bus(frozen_bus, eeh_report_mmio_enabled, &result);
}
}
/* If all devices reported they can proceed, then re-enable DMA */
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
rc = rtas_pci_enable(frozen_pdn, EEH_THAW_DMA);
if (rc < 0)
goto hard_fail;
if (rc)
result = PCI_ERS_RESULT_NEED_RESET;
else
result = PCI_ERS_RESULT_RECOVERED;
}
/* If any device has a hard failure, then shut off everything. */
if (result == PCI_ERS_RESULT_DISCONNECT) {
printk(KERN_WARNING "EEH: Device driver gave up\n");
goto hard_fail;
}
/* If any device called out for a reset, then reset the slot */
if (result == PCI_ERS_RESULT_NEED_RESET) {
rc = eeh_reset_device(frozen_pdn, NULL);
if (rc) {
printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc);
goto hard_fail;
}
result = PCI_ERS_RESULT_NONE;
pci_walk_bus(frozen_bus, eeh_report_reset, &result);
}
/* All devices should claim they have recovered by now. */
if ((result != PCI_ERS_RESULT_RECOVERED) &&
(result != PCI_ERS_RESULT_NONE)) {
printk(KERN_WARNING "EEH: Not recovered\n");
goto hard_fail;
}
/* Tell all device drivers that they can resume operations */
pci_walk_bus(frozen_bus, eeh_report_resume, NULL);
return frozen_pdn;
excess_failures:
/*
* About 90% of all real-life EEH failures in the field
* are due to poorly seated PCI cards. Only 10% or so are
* due to actual, failed cards.
*/
printk(KERN_ERR
"EEH: PCI device at location=%s driver=%s pci addr=%s\n"
"has failed %d times in the last hour "
"and has been permanently disabled.\n"
"Please try reseating this device or replacing it.\n",
location, drv_str, pci_str, frozen_pdn->eeh_freeze_count);
goto perm_error;
hard_fail:
printk(KERN_ERR
"EEH: Unable to recover from failure of PCI device "
"at location=%s driver=%s pci addr=%s\n"
"Please try reseating this device or replacing it.\n",
location, drv_str, pci_str);
perm_error:
eeh_slot_error_detail(frozen_pdn, EEH_LOG_PERM_FAILURE);
/* Notify all devices that they're about to go down. */
pci_walk_bus(frozen_bus, eeh_report_failure, NULL);
/* Shut down the device drivers for good. */
pcibios_remove_pci_devices(frozen_bus);
return NULL;
}
/* ---------- end of file ---------- */
