/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright (C) 2004, 2005 Linas Vepstas <linas@linas.org>
*
* 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 feedback to <linas@us.ibm.com>
*
*/
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/notifier.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->dev.driver)
return pdev->dev.driver->name;
return "";
}
#ifdef DEBUG
static void print_device_node_tree (struct pci_dn *pdn, int dent)
{
int i;
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;
struct device_node *pc = pdn->node->child;
while (pc) {
print_device_node_tree(PCI_DN(pc), dent);
pc = pc->sibling;
}
}
#endif
/**
* irq_in_use - return true if this irq is being used
*/
static int irq_in_use(unsigned int irq)
{
int rc = 0;
unsigned long flags;
struct irq_desc *desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
if (desc->action)
rc = 1;
spin_unlock_irqrestore(&desc->lock, flags);
return rc;
}
/* ------------------------------------------------------- */
/** eeh_report_error - report an EEH error to each device,
* collect up and merge the device responses.
*/
static void 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;
if (irq_in_use (dev->irq)) {
struct device_node *dn = pci_device_to_OF_node(dev);
PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->error_detected)
return;
rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen);
if (*res == PCI_ERS_RESULT_NONE) *res = rc;
if (*res == PCI_ERS_RESULT_NEED_RESET) return;
if (*res == PCI_ERS_RESULT_DISCONNECT &&
rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
}
/** eeh_report_reset -- tell this device that the pci slot
* has been reset.
*/
static void eeh_report_reset(struct pci_dev *dev, void *userdata)
{
struct pci_driver *driver = dev->driver;
struct device_node *dn = pci_device_to_OF_node(dev);
if (!driver)
return;
if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
enable_irq(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->slot_reset)
return;
driver->err_handler->slot_reset(dev);
}
static void 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;
if (!driver->err_handler)
return;
if (!driver->err_handler->resume)
return;
driver->err_handler->resume(dev);
}
static void 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;
if (irq_in_use (dev->irq)) {
struct device_node *dn = pci_device_to_OF_node(dev);
PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->error_detected)
return;
driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
}
/* ------------------------------------------------------- */
/**
* 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
* occuring 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
* Args: 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)
{
int rc;
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;
/* New-style config addrs might be shared across multiple devices,
* Walk over all functions on this device */
if (pe_dn->eeh_pe_config_addr) {
struct device_node *pe = pe_dn->node;
pe = pe->parent->child;
while (pe) {
struct pci_dn *ppe = PCI_DN(pe);
if (pe_dn->eeh_pe_config_addr == ppe->eeh_pe_config_addr) {
rtas_configure_bridge(ppe);
eeh_restore_bars(ppe);
}
pe = pe->sibling;
}
} else {
rtas_configure_bridge(pe_dn);
eeh_restore_bars(pe_dn);
}
/* 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);
}
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 15
void 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;
frozen_dn = find_device_pe(event->dn);
frozen_bus = pcibios_find_pci_bus(frozen_dn);
if (!frozen_dn) {
printk(KERN_ERR "EEH: Error: Cannot find partition endpoint for %s\n",
pci_name(event->dev));
return;
}
/* 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 %s\n",
frozen_dn->full_name);
return;
}
#if 0
/* We may get "permanent failure" messages on empty slots.
* These are false alarms. Empty slots have no child dn. */
if ((event->state == pci_channel_io_perm_failure) && (frozen_device == NULL))
return;
#endif
frozen_pdn = PCI_DN(frozen_dn);
frozen_pdn->eeh_freeze_count++;
if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES)
goto hard_fail;
/* If the reset state is a '5' and the time to reset is 0 (infinity)
* or is more then 15 seconds, then mark this as a permanent failure.
*/
if ((event->state == pci_channel_io_perm_failure) &&
((event->time_unavail <= 0) ||
(event->time_unavail > MAX_WAIT_FOR_RECOVERY*1000)))
goto hard_fail;
eeh_slot_error_detail(frozen_pdn, 1 /* Temporary Error */);
printk(KERN_WARNING
"EEH: This PCI device has failed %d times since last reboot: %s - %s\n",
frozen_pdn->eeh_freeze_count,
pci_name (frozen_pdn->pcidev),
pcid_name(frozen_pdn->pcidev));
/* 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);
/* 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)
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)
goto hard_fail;
pci_walk_bus(frozen_bus, eeh_report_reset, 0);
}
/* If all devices reported they can proceed, the re-enable PIO */
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
/* XXX Not supported; we brute-force reset the device */
rc = eeh_reset_device(frozen_pdn, NULL);
if (rc)
goto hard_fail;
pci_walk_bus(frozen_bus, eeh_report_reset, 0);
}
/* Tell all device drivers that they can resume operations */
pci_walk_bus(frozen_bus, eeh_report_resume, 0);
return;
hard_fail:
/*
* 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 %s - %s has failed %d times \n"
"and has been permanently disabled. Please try reseating\n"
"this device or replacing it.\n",
pci_name (frozen_pdn->pcidev),
pcid_name(frozen_pdn->pcidev),
frozen_pdn->eeh_freeze_count);
eeh_slot_error_detail(frozen_pdn, 2 /* Permanent Error */);
/* Notify all devices that they're about to go down. */
pci_walk_bus(frozen_bus, eeh_report_failure, 0);
/* Shut down the device drivers for good. */
pcibios_remove_pci_devices(frozen_bus);
}
/* ---------- end of file ---------- */
