[PATCH] PPC64: EEH Recovery

From: Linas Vepstas
Date: Wed Nov 17 2004 - 19:17:44 EST


Hi Paul,

The patch below implements hotplug style EEH error recovery.
Its split into two pieces: a part that needs to be applied to the
PPC64 arch tree, and a part that needs to be applied to the
RPA PHP hotplug tree. The PPC64 part needs to go in first.

Assuming this doesn't generate a round of discussion, please
forward upstream to akpm/torvalds.

Signed-off-by: Linas Vepstas <linas@xxxxxxxxx>

===== arch/ppc64/kernel/eeh.c 1.40 vs edited =====
--- 1.40/arch/ppc64/kernel/eeh.c 2004-10-25 14:47:50 -05:00
+++ edited/arch/ppc64/kernel/eeh.c 2004-11-17 17:31:41 -06:00
@@ -17,21 +17,19 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/

-#include <linux/bootmem.h>
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/list.h>
-#include <linux/mm.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/seq_file.h>
-#include <linux/spinlock.h>
+#include <asm/atomic.h>
#include <asm/eeh.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/rtas.h>
-#include <asm/atomic.h>
#include "pci.h"

#undef DEBUG
@@ -89,7 +87,6 @@ static struct notifier_block *eeh_notifi
* attempts we allow before panicking.
*/
#define EEH_MAX_FAILS 1000
-static atomic_t eeh_fail_count;

/* RTAS tokens */
static int ibm_set_eeh_option;
@@ -223,9 +220,9 @@ pci_addr_cache_insert(struct pci_dev *de
while (*p) {
parent = *p;
piar = rb_entry(parent, struct pci_io_addr_range, rb_node);
- if (alo < piar->addr_lo) {
+ if (ahi < piar->addr_lo) {
p = &parent->rb_left;
- } else if (ahi > piar->addr_hi) {
+ } else if (alo > piar->addr_hi) {
p = &parent->rb_right;
} else {
if (dev != piar->pcidev ||
@@ -243,6 +240,11 @@ pci_addr_cache_insert(struct pci_dev *de
piar->addr_hi = ahi;
piar->pcidev = dev;
piar->flags = flags;
+
+#ifdef DEBUG
+ printk (KERN_DEBUG "PIAR: insert range=[%lx:%lx] dev=%s\n",
+ alo, ahi, pci_name (dev));
+#endif

rb_link_node(&piar->rb_node, parent, p);
rb_insert_color(&piar->rb_node, &pci_io_addr_cache_root.rb_root);
@@ -377,6 +379,9 @@ void __init pci_addr_cache_build(void)
continue;
}
pci_addr_cache_insert_device(dev);
+
+ /* Save the BAR's; firmware doesn't restore these after EEH reset */
+ pci_save_state (dev);
}

#ifdef DEBUG
@@ -388,6 +393,32 @@ void __init pci_addr_cache_build(void)
/* --------------------------------------------------------------- */
/* Above lies the PCI Address Cache. Below lies the EEH event infrastructure */

+void eeh_slot_error_detail (struct device_node *dn, int severity)
+{
+ unsigned long flags;
+ int rc;
+
+ if (!dn) return;
+
+ /* Log the error with the rtas logger */
+ spin_lock_irqsave(&slot_errbuf_lock, flags);
+ memset(slot_errbuf, 0, eeh_error_buf_size);
+
+ rc = rtas_call(ibm_slot_error_detail,
+ 8, 1, NULL, dn->eeh_config_addr,
+ BUID_HI(dn->phb->buid),
+ BUID_LO(dn->phb->buid), NULL, 0,
+ virt_to_phys(slot_errbuf),
+ eeh_error_buf_size,
+ severity);
+
+ if (rc == 0)
+ log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
+ spin_unlock_irqrestore(&slot_errbuf_lock, flags);
+}
+
+EXPORT_SYMBOL(eeh_slot_error_detail);
+
/**
* eeh_register_notifier - Register to find out about EEH events.
* @nb: notifier block to callback on events
@@ -462,11 +493,9 @@ static void eeh_event_handler(void *dumm
"%s %s\n", event->reset_state,
pci_name(event->dev), pci_pretty_name(event->dev));

- atomic_set(&eeh_fail_count, 0);
- notifier_call_chain (&eeh_notifier_chain,
- EEH_NOTIFY_FREEZE, event);
-
__get_cpu_var(slot_resets)++;
+ notifier_call_chain (&eeh_notifier_chain,
+ EEH_NOTIFY_FREEZE, event);

pci_dev_put(event->dev);
kfree(event);
@@ -510,7 +539,7 @@ int eeh_dn_check_failure(struct device_n
int ret;
int rets[2];
unsigned long flags;
- int rc, reset_state;
+ int reset_state;
struct eeh_event *event;

__get_cpu_var(total_mmio_ffs)++;
@@ -530,14 +559,15 @@ int eeh_dn_check_failure(struct device_n
if (!dn->eeh_config_addr) {
return 0;
}
-
+
/*
* If we already have a pending isolation event for this
* slot, we know it's bad already, we don't need to check...
*/
if (dn->eeh_mode & EEH_MODE_ISOLATED) {
- atomic_inc(&eeh_fail_count);
- if (atomic_read(&eeh_fail_count) >= EEH_MAX_FAILS) {
+ dn->eeh_freeze_count ++;
+ if (dn->eeh_freeze_count >= EEH_MAX_FAILS) {
+ dump_stack();
/* re-read the slot reset state */
rets[0] = -1;
rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
@@ -565,28 +595,17 @@ int eeh_dn_check_failure(struct device_n
return 0;
}

- /* prevent repeated reports of this failure */
+ /* Prevent repeated reports of this failure */
dn->eeh_mode |= EEH_MODE_ISOLATED;

reset_state = rets[0];
+ /* Log the error with the rtas logger */
+ if (dn->eeh_freeze_count < EEH_MAX_ALLOWED_FREEZES) {
+ eeh_slot_error_detail (dn, 1 /* Temporary Error */);
+ } else {
+ eeh_slot_error_detail (dn, 2 /* Permanent Error */);
+ }

- spin_lock_irqsave(&slot_errbuf_lock, flags);
- memset(slot_errbuf, 0, eeh_error_buf_size);
-
- rc = rtas_call(ibm_slot_error_detail,
- 8, 1, NULL, dn->eeh_config_addr,
- BUID_HI(dn->phb->buid),
- BUID_LO(dn->phb->buid), NULL, 0,
- virt_to_phys(slot_errbuf),
- eeh_error_buf_size,
- 1 /* Temporary Error */);
-
- if (rc == 0)
- log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
- spin_unlock_irqrestore(&slot_errbuf_lock, flags);
-
- printk(KERN_INFO "EEH: MMIO failure (%d) on device: %s %s\n",
- rets[0], dn->name, dn->full_name);
event = kmalloc(sizeof(*event), GFP_ATOMIC);
if (event == NULL) {
eeh_panic(dev, reset_state);
@@ -618,7 +637,6 @@ EXPORT_SYMBOL(eeh_dn_check_failure);
* @token i/o token, should be address in the form 0xA....
* @val value, should be all 1's (XXX why do we need this arg??)
*
- * Check for an eeh failure at the given token address.
* Check for an EEH failure at the given token address. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze event. This routine
@@ -626,6 +644,7 @@ EXPORT_SYMBOL(eeh_dn_check_failure);
*
* Note this routine is safe to call in an interrupt context.
*/
+
unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val)
{
unsigned long addr;
@@ -635,7 +654,7 @@ unsigned long eeh_check_failure(const vo
/* Finding the phys addr + pci device; this is pretty quick. */
addr = eeh_token_to_phys((unsigned long __force) token);
dev = pci_get_device_by_addr(addr);
- if (!dev)
+ if (!dev)
return val;

dn = pci_device_to_OF_node(dev);
@@ -647,6 +666,174 @@ unsigned long eeh_check_failure(const vo

EXPORT_SYMBOL(eeh_check_failure);

+/* ------------------------------------------------------------- */
+/* The code below deals with error recovery */
+
+void
+rtas_set_slot_reset(struct device_node *dn)
+{
+ int token = rtas_token ("ibm,set-slot-reset");
+ int rc;
+
+ if (token == RTAS_UNKNOWN_SERVICE)
+ return;
+ rc = rtas_call(token,4,1, NULL,
+ dn->eeh_config_addr,
+ BUID_HI(dn->phb->buid),
+ BUID_LO(dn->phb->buid),
+ 1);
+ if (rc) {
+ printk (KERN_WARNING "EEH: Unable to reset the failed slot\n");
+ return;
+ }
+
+ /* The PCI bus requires that the reset be held high for at least
+ * a 100 milliseconds. We wait a bit longer 'just in case'.
+ */
+ msleep (200);
+
+ rc = rtas_call(token,4,1, NULL,
+ dn->eeh_config_addr,
+ BUID_HI(dn->phb->buid),
+ BUID_LO(dn->phb->buid),
+ 0);
+}
+
+EXPORT_SYMBOL(rtas_set_slot_reset);
+
+void
+rtas_configure_bridge(struct device_node *dn)
+{
+ int token = rtas_token ("ibm,configure-bridge");
+ int rc;
+
+ if (token == RTAS_UNKNOWN_SERVICE)
+ return;
+ rc = rtas_call(token,3,1, NULL,
+ dn->eeh_config_addr,
+ BUID_HI(dn->phb->buid),
+ BUID_LO(dn->phb->buid));
+ if (rc) {
+ printk (KERN_WARNING "EEH: Unable to configure device bridge\n");
+ }
+}
+
+EXPORT_SYMBOL(rtas_configure_bridge);
+
+/* ------------------------------------------------------- */
+/** Save and restore of PCI BARs
+ *
+ * Although firmware will set up BARs during boot, it doesn't
+ * set up device BAR's after a device reset, although it will,
+ * if requested, set up bridge configuration. Thus, we need to
+ * configure the PCI devices ourselves. Config-space setup is
+ * stored in the PCI structures which are normally deleted during
+ * device removal. Thus, the "save" routine references the
+ * structures so that they aren't deleted.
+ */
+
+
+struct eeh_cfg_tree
+{
+ struct eeh_cfg_tree *sibling;
+ struct eeh_cfg_tree *child;
+ struct pci_dev *dev;
+ struct device_node *dn;
+};
+
+static inline struct pci_dev * eeh_get_pci_dev(struct device_node *dn)
+{
+ struct pci_dev *dev = NULL;
+ char bus_id[BUS_ID_SIZE];
+
+ sprintf(bus_id, "%04x:%02x:%02x.%d",dn->phb->global_number,
+ dn->busno, PCI_SLOT(dn->devfn), PCI_FUNC(dn->devfn));
+
+ while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
+ if (!strcmp(pci_name(dev), bus_id))
+ return dev;
+ }
+ return NULL;
+}
+
+/**
+ * eeh_save_bars - save the PCI config space info
+ */
+struct eeh_cfg_tree * eeh_save_bars(struct device_node *dn)
+{
+ struct eeh_cfg_tree *cnode;
+ struct pci_dev *dev;
+
+ dev = eeh_get_pci_dev (dn);
+ if (!dev)
+ return NULL;
+
+ cnode = kmalloc(sizeof(struct eeh_cfg_tree), GFP_KERNEL);
+ if (!cnode)
+ return NULL;
+
+ cnode->dev = dev;
+
+ of_node_get(dn);
+ cnode->dn = dn;
+
+ cnode->sibling = NULL;
+ cnode->child = NULL;
+
+ if (dn->child) {
+ cnode->child = eeh_save_bars (dn->child);
+ }
+ if (dn->sibling) {
+ cnode->sibling = eeh_save_bars (dn->sibling);
+ }
+
+ return cnode;
+}
+EXPORT_SYMBOL(eeh_save_bars);
+
+/**
+ * __restore_bars - Restore the Base Address Registers
+ * Loads the PCI configuration space base address registers
+ * and the expansion ROM base address from the array
+ * passed as the second argument.
+ */
+static inline void __restore_bars (struct device_node *dn, u32 *cfg_hdr)
+{
+ int i;
+ for (i=4; i<10; i++) {
+ rtas_write_config(dn, i*4, 4, cfg_hdr[i]);
+ }
+ rtas_write_config(dn, 12*4, 4, cfg_hdr[12]);
+}
+
+/**
+ * eeh_restore_bars - restore the PCI config space info
+ */
+void eeh_restore_bars(struct eeh_cfg_tree *tree)
+{
+ if (tree->dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
+ __restore_bars (tree->dn, tree->dev->saved_config_space);
+ }
+
+ if (tree->child) {
+ eeh_restore_bars (tree->child);
+ }
+ if (tree->sibling) {
+ eeh_restore_bars (tree->sibling);
+ }
+
+ of_node_put (tree->dn);
+ pci_dev_put (tree->dev);
+ kfree (tree);
+}
+EXPORT_SYMBOL(eeh_restore_bars);
+
+/* ------------------------------------------------------------- */
+/* The code below deals with enabling EEH for devices during the
+ * early boot sequence. EEH must be enabled before any PCI probing
+ * can be done.
+ */
+
struct eeh_early_enable_info {
unsigned int buid_hi;
unsigned int buid_lo;
@@ -840,6 +1027,9 @@ void eeh_add_device_late(struct pci_dev
#endif

pci_addr_cache_insert_device (dev);
+
+ /* Save the BAR's; firmware doesn't restore these after EEH reset */
+ pci_save_state (dev);
}
EXPORT_SYMBOL(eeh_add_device_late);

@@ -885,10 +1075,8 @@ static int proc_eeh_show(struct seq_file
seq_printf(m, "eeh_total_mmio_ffs=%ld\n"
"eeh_false_positives=%ld\n"
"eeh_ignored_failures=%ld\n"
- "eeh_slot_resets=%ld\n"
- "eeh_fail_count=%d\n",
- ffs, positives, failures, resets,
- eeh_fail_count.counter);
+ "eeh_slot_resets=%ld\n",
+ ffs, positives, failures, resets);
}

return 0;
===== arch/ppc64/kernel/pSeries_pci.c 1.59 vs edited =====
--- 1.59/arch/ppc64/kernel/pSeries_pci.c 2004-11-15 21:29:10 -06:00
+++ edited/arch/ppc64/kernel/pSeries_pci.c 2004-11-17 16:18:02 -06:00
@@ -102,7 +102,7 @@ static int rtas_pci_read_config(struct p
return PCIBIOS_DEVICE_NOT_FOUND;
}

-static int rtas_write_config(struct device_node *dn, int where, int size, u32 val)
+int rtas_write_config(struct device_node *dn, int where, int size, u32 val)
{
unsigned long buid, addr;
int ret;
@@ -125,6 +125,7 @@ static int rtas_write_config(struct devi

return PCIBIOS_SUCCESSFUL;
}
+EXPORT_SYMBOL(rtas_write_config);

static int rtas_pci_write_config(struct pci_bus *bus,
unsigned int devfn,
===== include/asm-ppc64/eeh.h 1.23 vs edited =====
--- 1.23/include/asm-ppc64/eeh.h 2004-10-25 18:17:38 -05:00
+++ edited/include/asm-ppc64/eeh.h 2004-11-17 16:10:58 -06:00
@@ -22,8 +22,8 @@

#include <linux/init.h>
#include <linux/list.h>
-#include <linux/string.h>
#include <linux/notifier.h>
+#include <linux/string.h>

struct pci_dev;
struct device_node;
@@ -33,6 +33,10 @@ struct device_node;
#define EEH_MODE_NOCHECK (1<<1)
#define EEH_MODE_ISOLATED (1<<2)

+/* Max number of EEH freezes allowed before we consider the device
+ * to be permanently disabled. */
+#define EEH_MAX_ALLOWED_FREEZES 5
+
#ifdef CONFIG_PPC_PSERIES
extern void __init eeh_init(void);
unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val);
@@ -57,6 +61,34 @@ void eeh_add_device_early(struct device_
void eeh_add_device_late(struct pci_dev *);

/**
+ * eeh_slot_error_detail -- record and EEH error condition to the log
+ * @severity: 1 if temporary, 2 if permanent failure.
+ *
+ * Obtains the the EEH error details from the RTAS subsystem,
+ * and then logs these details with the RTAS error log system.
+ */
+void eeh_slot_error_detail (struct device_node *dn, int severity);
+
+/**
+ * rtas_set_slot_reset -- unfreeze a frozen slot
+ *
+ * Clear the EEH-frozen condition on a slot. This routine
+ * does this by asserting the PCI #RST line for 1/8th of
+ * a second; this routine will sleep while the adapter is
+ * being reset.
+ */
+void rtas_set_slot_reset (struct device_node *dn);
+
+/**
+ * rtas_configure_bridge -- firmware initialization of pci bridge
+ *
+ * Ask the firmware to configure any PCI bridge devices
+ * located behind the indicated node. Required after a
+ * pci device reset.
+ */
+void rtas_configure_bridge(struct device_node *dn);
+
+/**
* eeh_remove_device - undo EEH setup for the indicated pci device
* @dev: pci device to be removed
*
@@ -91,6 +123,13 @@ struct eeh_event {
/** Register to find out about EEH events. */
int eeh_register_notifier(struct notifier_block *nb);
int eeh_unregister_notifier(struct notifier_block *nb);
+
+/** Save and restore device configuration info across
+ * device resets
+ */
+struct eeh_cfg_tree;
+struct eeh_cfg_tree * eeh_save_bars(struct device_node *dn);
+void eeh_restore_bars(struct eeh_cfg_tree *tree);

/**
* EEH_POSSIBLE_ERROR() -- test for possible MMIO failure.
===== include/asm-ppc64/prom.h 1.23 vs edited =====
--- 1.23/include/asm-ppc64/prom.h 2004-10-24 20:55:43 -05:00
+++ edited/include/asm-ppc64/prom.h 2004-11-17 16:00:37 -06:00
@@ -162,6 +162,7 @@ struct device_node {
int status; /* Current device status (non-zero is bad) */
int eeh_mode; /* See eeh.h for possible EEH_MODEs */
int eeh_config_addr;
+ int eeh_freeze_count; /* number of times this device froze up. */
struct pci_controller *phb; /* for pci devices */
struct iommu_table *iommu_table; /* for phb's or bridges */

===== include/asm-ppc64/rtas.h 1.24 vs edited =====
--- 1.24/include/asm-ppc64/rtas.h 2004-09-22 00:42:53 -05:00
+++ edited/include/asm-ppc64/rtas.h 2004-11-17 16:00:37 -06:00
@@ -241,4 +241,6 @@ extern void rtas_stop_self(void);
/* RMO buffer reserved for user-space RTAS use */
extern unsigned long rtas_rmo_buf;

+extern int rtas_write_config(struct device_node *dn, int where, int size, u32 val);
+
#endif /* _PPC64_RTAS_H */
===== drivers/pci/hotplug/rpaphp.h 1.11 vs edited =====
--- 1.11/drivers/pci/hotplug/rpaphp.h 2004-10-06 11:43:44 -05:00
+++ edited/drivers/pci/hotplug/rpaphp.h 2004-11-17 16:00:37 -06:00
@@ -126,6 +126,8 @@ extern int register_pci_slot(struct slot
extern int rpaphp_unconfig_pci_adapter(struct slot *slot);
extern int rpaphp_get_pci_adapter_status(struct slot *slot, int is_init, u8 * value);
extern struct hotplug_slot *rpaphp_find_hotplug_slot(struct pci_dev *dev);
+extern void init_eeh_handler (void);
+extern void exit_eeh_handler (void);

/* rpaphp_core.c */
extern int rpaphp_add_slot(struct device_node *dn);
===== drivers/pci/hotplug/rpaphp_core.c 1.18 vs edited =====
--- 1.18/drivers/pci/hotplug/rpaphp_core.c 2004-10-06 11:43:44 -05:00
+++ edited/drivers/pci/hotplug/rpaphp_core.c 2004-11-17 16:00:37 -06:00
@@ -443,12 +443,18 @@ static int __init rpaphp_init(void)
{
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");

+ /* Get set to handle EEH events. */
+ init_eeh_handler();
+
/* read all the PRA info from the system */
return init_rpa();
}

static void __exit rpaphp_exit(void)
{
+ /* Let EEH know we are going away. */
+ exit_eeh_handler();
+
cleanup_slots();
}

===== drivers/pci/hotplug/rpaphp_pci.c 1.16 vs edited =====
--- 1.16/drivers/pci/hotplug/rpaphp_pci.c 2004-10-19 11:54:38 -05:00
+++ edited/drivers/pci/hotplug/rpaphp_pci.c 2004-11-17 17:23:39 -06:00
@@ -22,8 +22,12 @@
* Send feedback to <lxie@xxxxxxxxxx>
*
*/
+#include <linux/delay.h>
+#include <linux/notifier.h>
#include <linux/pci.h>
+#include <asm/eeh.h>
#include <asm/pci-bridge.h>
+#include <asm/prom.h>
#include <asm/rtas.h>
#include "../pci.h" /* for pci_add_new_bus */

@@ -63,6 +67,7 @@ int rpaphp_claim_resource(struct pci_dev
root ? "Address space collision on" :
"No parent found for",
resource, dtype, pci_name(dev), res->start, res->end);
+ dump_stack();
}
return err;
}
@@ -185,6 +190,19 @@ rpaphp_fixup_new_pci_devices(struct pci_

static int rpaphp_pci_config_bridge(struct pci_dev *dev);

+static void rpaphp_eeh_add_bus_device(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ eeh_add_device_late(dev);
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ struct pci_bus *subbus = dev->subordinate;
+ if (bus)
+ rpaphp_eeh_add_bus_device (subbus);
+ }
+ }
+}
+
/*****************************************************************************
rpaphp_pci_config_slot() will configure all devices under the
given slot->dn and return the the first pci_dev.
@@ -212,6 +230,8 @@ rpaphp_pci_config_slot(struct device_nod
}
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
rpaphp_pci_config_bridge(dev);
+
+ rpaphp_eeh_add_bus_device(bus);
}
return dev;
}
@@ -220,7 +240,6 @@ static int rpaphp_pci_config_bridge(stru
{
u8 sec_busno;
struct pci_bus *child_bus;
- struct pci_dev *child_dev;

dbg("Enter %s: BRIDGE dev=%s\n", __FUNCTION__, pci_name(dev));

@@ -237,11 +256,7 @@ static int rpaphp_pci_config_bridge(stru
/* do pci_scan_child_bus */
pci_scan_child_bus(child_bus);

- list_for_each_entry(child_dev, &child_bus->devices, bus_list) {
- eeh_add_device_late(child_dev);
- }
-
- /* fixup new pci devices without touching bus struct */
+ /* Fixup new pci devices without touching bus struct */
rpaphp_fixup_new_pci_devices(child_bus, 0);

/* Make the discovered devices available */
@@ -279,7 +294,7 @@ static void print_slot_pci_funcs(struct
return;
}
#else
-static void print_slot_pci_funcs(struct slot *slot)
+static inline void print_slot_pci_funcs(struct slot *slot)
{
return;
}
@@ -361,7 +376,6 @@ static void rpaphp_eeh_remove_bus_device
if (pdev)
rpaphp_eeh_remove_bus_device(pdev);
}
-
}
return;
}
@@ -563,10 +577,14 @@ exit:
return retval;
}

-struct hotplug_slot *rpaphp_find_hotplug_slot(struct pci_dev *dev)
+/**
+ * rpaphp_find_slot - find and return the slot holding the device
+ * @dev: pci device for which we want the slot structure.
+ */
+static struct slot *rpaphp_find_slot(struct pci_dev *dev)
{
- struct list_head *tmp, *n;
- struct slot *slot;
+ struct list_head *tmp, *n;
+ struct slot *slot;

list_for_each_safe(tmp, n, &rpaphp_slot_head) {
struct pci_bus *bus;
@@ -585,14 +603,109 @@ struct hotplug_slot *rpaphp_find_hotplug
if (!bus) {
continue; /* should never happen? */
}
+
for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
- struct pci_dev *pdev = pci_dev_b(ln);
- if (pdev == dev)
- return slot->hotplug_slot;
+ struct pci_dev *pdev = pci_dev_b(ln);
+ if (pdev == dev)
+ return slot;
}
}

return NULL;
}

-EXPORT_SYMBOL_GPL(rpaphp_find_hotplug_slot);
+/* ------------------------------------------------------- */
+/**
+ * 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).
+ */
+int handle_eeh_events (struct notifier_block *self,
+ unsigned long reason, void *ev)
+{
+ struct eeh_event *event = ev;
+ struct slot *frozen_slot;
+ struct eeh_cfg_tree * saved_bars;
+
+ frozen_slot = rpaphp_find_slot(event->dev);
+ if (!frozen_slot)
+ {
+ printk (KERN_ERR
+ "EEH: Cannot find PCI slot for EEH error! dev=%p dn=%p\n",
+ event->dev, event->dn);
+ return 1;
+ }
+
+ /* Keep a copy of the config space registers */
+ saved_bars = eeh_save_bars(frozen_slot->dn);
+ of_node_get(event->dn);
+ pci_dev_get(event->dev);
+
+ rpaphp_unconfig_pci_adapter (frozen_slot);
+
+ event->dn->eeh_freeze_count ++;
+ if (event->dn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES) {
+ /*
+ * 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: 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 (event->dev),
+ pci_pretty_name (event->dev),
+ EEH_MAX_ALLOWED_FREEZES);
+ goto rdone;
+ }
+
+ /* Reset the pci controller. (Asserts RST#; resets config space).
+ * Reconfigure bridges and devices */
+ rtas_set_slot_reset (event->dn);
+ rtas_configure_bridge(event->dn);
+ eeh_restore_bars(saved_bars);
+
+ /* Give the system 5 seconds to finish running the user-space
+ * hotplug scripts, e.g. ifdown for ethernet. Yes, this is a hack,
+ * but if we don't do this, weird things happen.
+ */
+ ssleep (5);
+
+ rpaphp_enable_pci_slot (frozen_slot);
+
+ /* The new device node is different than the old one;
+ * copy over the freeze count, so that we don't loose track of it.
+ */
+ frozen_slot->dn->eeh_freeze_count = event->dn->eeh_freeze_count;
+rdone:
+ of_node_put(event->dn);
+ pci_dev_put(event->dev);
+ return 0;
+}
+
+static struct notifier_block eeh_block;
+
+void __init init_eeh_handler (void)
+{
+ eeh_block.notifier_call = handle_eeh_events;
+ eeh_register_notifier (&eeh_block);
+}
+
+void __exit exit_eeh_handler (void)
+{
+ eeh_unregister_notifier (&eeh_block);
+}
+