diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/eeh.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/eeh.c | 1212 |
1 files changed, 1212 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c new file mode 100644 index 00000000000..79de2310e70 --- /dev/null +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -0,0 +1,1212 @@ +/* + * eeh.c + * Copyright (C) 2001 Dave Engebretsen & Todd Inglett IBM Corporation + * + * 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. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/list.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/eeh_event.h> +#include <asm/io.h> +#include <asm/machdep.h> +#include <asm/ppc-pci.h> +#include <asm/rtas.h> + +#undef DEBUG + +/** Overview: + * EEH, or "Extended Error Handling" is a PCI bridge technology for + * dealing with PCI bus errors that can't be dealt with within the + * usual PCI framework, except by check-stopping the CPU. Systems + * that are designed for high-availability/reliability cannot afford + * to crash due to a "mere" PCI error, thus the need for EEH. + * An EEH-capable bridge operates by converting a detected error + * into a "slot freeze", taking the PCI adapter off-line, making + * the slot behave, from the OS'es point of view, as if the slot + * were "empty": all reads return 0xff's and all writes are silently + * ignored. EEH slot isolation events can be triggered by parity + * errors on the address or data busses (e.g. during posted writes), + * which in turn might be caused by low voltage on the bus, dust, + * vibration, humidity, radioactivity or plain-old failed hardware. + * + * Note, however, that one of the leading causes of EEH slot + * freeze events are buggy device drivers, buggy device microcode, + * or buggy device hardware. This is because any attempt by the + * device to bus-master data to a memory address that is not + * assigned to the device will trigger a slot freeze. (The idea + * is to prevent devices-gone-wild from corrupting system memory). + * Buggy hardware/drivers will have a miserable time co-existing + * with EEH. + * + * Ideally, a PCI device driver, when suspecting that an isolation + * event has occured (e.g. by reading 0xff's), will then ask EEH + * whether this is the case, and then take appropriate steps to + * reset the PCI slot, the PCI device, and then resume operations. + * However, until that day, the checking is done here, with the + * eeh_check_failure() routine embedded in the MMIO macros. If + * the slot is found to be isolated, an "EEH Event" is synthesized + * and sent out for processing. + */ + +/* If a device driver keeps reading an MMIO register in an interrupt + * handler after a slot isolation event has occurred, we assume it + * is broken and panic. This sets the threshold for how many read + * attempts we allow before panicking. + */ +#define EEH_MAX_FAILS 100000 + +/* Misc forward declaraions */ +static void eeh_save_bars(struct pci_dev * pdev, struct pci_dn *pdn); + +/* RTAS tokens */ +static int ibm_set_eeh_option; +static int ibm_set_slot_reset; +static int ibm_read_slot_reset_state; +static int ibm_read_slot_reset_state2; +static int ibm_slot_error_detail; + +static int eeh_subsystem_enabled; + +/* Lock to avoid races due to multiple reports of an error */ +static DEFINE_SPINLOCK(confirm_error_lock); + +/* Buffer for reporting slot-error-detail rtas calls */ +static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX]; +static DEFINE_SPINLOCK(slot_errbuf_lock); +static int eeh_error_buf_size; + +/* System monitoring statistics */ +static DEFINE_PER_CPU(unsigned long, no_device); +static DEFINE_PER_CPU(unsigned long, no_dn); +static DEFINE_PER_CPU(unsigned long, no_cfg_addr); +static DEFINE_PER_CPU(unsigned long, ignored_check); +static DEFINE_PER_CPU(unsigned long, total_mmio_ffs); +static DEFINE_PER_CPU(unsigned long, false_positives); +static DEFINE_PER_CPU(unsigned long, ignored_failures); +static DEFINE_PER_CPU(unsigned long, slot_resets); + +/** + * The pci address cache subsystem. This subsystem places + * PCI device address resources into a red-black tree, sorted + * according to the address range, so that given only an i/o + * address, the corresponding PCI device can be **quickly** + * found. It is safe to perform an address lookup in an interrupt + * context; this ability is an important feature. + * + * Currently, the only customer of this code is the EEH subsystem; + * thus, this code has been somewhat tailored to suit EEH better. + * In particular, the cache does *not* hold the addresses of devices + * for which EEH is not enabled. + * + * (Implementation Note: The RB tree seems to be better/faster + * than any hash algo I could think of for this problem, even + * with the penalty of slow pointer chases for d-cache misses). + */ +struct pci_io_addr_range +{ + struct rb_node rb_node; + unsigned long addr_lo; + unsigned long addr_hi; + struct pci_dev *pcidev; + unsigned int flags; +}; + +static struct pci_io_addr_cache +{ + struct rb_root rb_root; + spinlock_t piar_lock; +} pci_io_addr_cache_root; + +static inline struct pci_dev *__pci_get_device_by_addr(unsigned long addr) +{ + struct rb_node *n = pci_io_addr_cache_root.rb_root.rb_node; + + while (n) { + struct pci_io_addr_range *piar; + piar = rb_entry(n, struct pci_io_addr_range, rb_node); + + if (addr < piar->addr_lo) { + n = n->rb_left; + } else { + if (addr > piar->addr_hi) { + n = n->rb_right; + } else { + pci_dev_get(piar->pcidev); + return piar->pcidev; + } + } + } + + return NULL; +} + +/** + * pci_get_device_by_addr - Get device, given only address + * @addr: mmio (PIO) phys address or i/o port number + * + * Given an mmio phys address, or a port number, find a pci device + * that implements this address. Be sure to pci_dev_put the device + * when finished. I/O port numbers are assumed to be offset + * from zero (that is, they do *not* have pci_io_addr added in). + * It is safe to call this function within an interrupt. + */ +static struct pci_dev *pci_get_device_by_addr(unsigned long addr) +{ + struct pci_dev *dev; + unsigned long flags; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + dev = __pci_get_device_by_addr(addr); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); + return dev; +} + +#ifdef DEBUG +/* + * Handy-dandy debug print routine, does nothing more + * than print out the contents of our addr cache. + */ +static void pci_addr_cache_print(struct pci_io_addr_cache *cache) +{ + struct rb_node *n; + int cnt = 0; + + n = rb_first(&cache->rb_root); + while (n) { + struct pci_io_addr_range *piar; + piar = rb_entry(n, struct pci_io_addr_range, rb_node); + printk(KERN_DEBUG "PCI: %s addr range %d [%lx-%lx]: %s\n", + (piar->flags & IORESOURCE_IO) ? "i/o" : "mem", cnt, + piar->addr_lo, piar->addr_hi, pci_name(piar->pcidev)); + cnt++; + n = rb_next(n); + } +} +#endif + +/* Insert address range into the rb tree. */ +static struct pci_io_addr_range * +pci_addr_cache_insert(struct pci_dev *dev, unsigned long alo, + unsigned long ahi, unsigned int flags) +{ + struct rb_node **p = &pci_io_addr_cache_root.rb_root.rb_node; + struct rb_node *parent = NULL; + struct pci_io_addr_range *piar; + + /* Walk tree, find a place to insert into tree */ + while (*p) { + parent = *p; + piar = rb_entry(parent, struct pci_io_addr_range, rb_node); + if (ahi < piar->addr_lo) { + p = &parent->rb_left; + } else if (alo > piar->addr_hi) { + p = &parent->rb_right; + } else { + if (dev != piar->pcidev || + alo != piar->addr_lo || ahi != piar->addr_hi) { + printk(KERN_WARNING "PIAR: overlapping address range\n"); + } + return piar; + } + } + piar = (struct pci_io_addr_range *)kmalloc(sizeof(struct pci_io_addr_range), GFP_ATOMIC); + if (!piar) + return NULL; + + piar->addr_lo = alo; + 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); + + return piar; +} + +static void __pci_addr_cache_insert_device(struct pci_dev *dev) +{ + struct device_node *dn; + struct pci_dn *pdn; + int i; + int inserted = 0; + + dn = pci_device_to_OF_node(dev); + if (!dn) { + printk(KERN_WARNING "PCI: no pci dn found for dev=%s\n", pci_name(dev)); + return; + } + + /* Skip any devices for which EEH is not enabled. */ + pdn = PCI_DN(dn); + if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) || + pdn->eeh_mode & EEH_MODE_NOCHECK) { +#ifdef DEBUG + printk(KERN_INFO "PCI: skip building address cache for=%s - %s\n", + pci_name(dev), pdn->node->full_name); +#endif + return; + } + + /* The cache holds a reference to the device... */ + pci_dev_get(dev); + + /* Walk resources on this device, poke them into the tree */ + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { + unsigned long start = pci_resource_start(dev,i); + unsigned long end = pci_resource_end(dev,i); + unsigned int flags = pci_resource_flags(dev,i); + + /* We are interested only bus addresses, not dma or other stuff */ + if (0 == (flags & (IORESOURCE_IO | IORESOURCE_MEM))) + continue; + if (start == 0 || ~start == 0 || end == 0 || ~end == 0) + continue; + pci_addr_cache_insert(dev, start, end, flags); + inserted = 1; + } + + /* If there was nothing to add, the cache has no reference... */ + if (!inserted) + pci_dev_put(dev); +} + +/** + * pci_addr_cache_insert_device - Add a device to the address cache + * @dev: PCI device whose I/O addresses we are interested in. + * + * In order to support the fast lookup of devices based on addresses, + * we maintain a cache of devices that can be quickly searched. + * This routine adds a device to that cache. + */ +static void pci_addr_cache_insert_device(struct pci_dev *dev) +{ + unsigned long flags; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + __pci_addr_cache_insert_device(dev); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); +} + +static inline void __pci_addr_cache_remove_device(struct pci_dev *dev) +{ + struct rb_node *n; + int removed = 0; + +restart: + n = rb_first(&pci_io_addr_cache_root.rb_root); + while (n) { + struct pci_io_addr_range *piar; + piar = rb_entry(n, struct pci_io_addr_range, rb_node); + + if (piar->pcidev == dev) { + rb_erase(n, &pci_io_addr_cache_root.rb_root); + removed = 1; + kfree(piar); + goto restart; + } + n = rb_next(n); + } + + /* The cache no longer holds its reference to this device... */ + if (removed) + pci_dev_put(dev); +} + +/** + * pci_addr_cache_remove_device - remove pci device from addr cache + * @dev: device to remove + * + * Remove a device from the addr-cache tree. + * This is potentially expensive, since it will walk + * the tree multiple times (once per resource). + * But so what; device removal doesn't need to be that fast. + */ +static void pci_addr_cache_remove_device(struct pci_dev *dev) +{ + unsigned long flags; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + __pci_addr_cache_remove_device(dev); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); +} + +/** + * pci_addr_cache_build - Build a cache of I/O addresses + * + * Build a cache of pci i/o addresses. This cache will be used to + * find the pci device that corresponds to a given address. + * This routine scans all pci busses to build the cache. + * Must be run late in boot process, after the pci controllers + * have been scaned for devices (after all device resources are known). + */ +void __init pci_addr_cache_build(void) +{ + struct device_node *dn; + struct pci_dev *dev = NULL; + + if (!eeh_subsystem_enabled) + return; + + spin_lock_init(&pci_io_addr_cache_root.piar_lock); + + while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { + /* Ignore PCI bridges ( XXX why ??) */ + if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE) { + continue; + } + pci_addr_cache_insert_device(dev); + + /* Save the BAR's; firmware doesn't restore these after EEH reset */ + dn = pci_device_to_OF_node(dev); + eeh_save_bars(dev, PCI_DN(dn)); + } + +#ifdef DEBUG + /* Verify tree built up above, echo back the list of addrs. */ + pci_addr_cache_print(&pci_io_addr_cache_root); +#endif +} + +/* --------------------------------------------------------------- */ +/* Above lies the PCI Address Cache. Below lies the EEH event infrastructure */ + +void eeh_slot_error_detail (struct pci_dn *pdn, int severity) +{ + unsigned long flags; + int rc; + + /* 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, pdn->eeh_config_addr, + BUID_HI(pdn->phb->buid), + BUID_LO(pdn->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); +} + +/** + * read_slot_reset_state - Read the reset state of a device node's slot + * @dn: device node to read + * @rets: array to return results in + */ +static int read_slot_reset_state(struct pci_dn *pdn, int rets[]) +{ + int token, outputs; + + if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) { + token = ibm_read_slot_reset_state2; + outputs = 4; + } else { + token = ibm_read_slot_reset_state; + rets[2] = 0; /* fake PE Unavailable info */ + outputs = 3; + } + + return rtas_call(token, 3, outputs, rets, pdn->eeh_config_addr, + BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid)); +} + +/** + * eeh_token_to_phys - convert EEH address token to phys address + * @token i/o token, should be address in the form 0xA.... + */ +static inline unsigned long eeh_token_to_phys(unsigned long token) +{ + pte_t *ptep; + unsigned long pa; + + ptep = find_linux_pte(init_mm.pgd, token); + if (!ptep) + return token; + pa = pte_pfn(*ptep) << PAGE_SHIFT; + + return pa | (token & (PAGE_SIZE-1)); +} + +/** + * Return the "partitionable endpoint" (pe) under which this device lies + */ +static struct device_node * find_device_pe(struct device_node *dn) +{ + while ((dn->parent) && PCI_DN(dn->parent) && + (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { + dn = dn->parent; + } + return dn; +} + +/** Mark all devices that are peers of this device as failed. + * Mark the device driver too, so that it can see the failure + * immediately; this is critical, since some drivers poll + * status registers in interrupts ... If a driver is polling, + * and the slot is frozen, then the driver can deadlock in + * an interrupt context, which is bad. + */ + +static void __eeh_mark_slot (struct device_node *dn, int mode_flag) +{ + while (dn) { + if (PCI_DN(dn)) { + PCI_DN(dn)->eeh_mode |= mode_flag; + + if (dn->child) + __eeh_mark_slot (dn->child, mode_flag); + } + dn = dn->sibling; + } +} + +void eeh_mark_slot (struct device_node *dn, int mode_flag) +{ + dn = find_device_pe (dn); + PCI_DN(dn)->eeh_mode |= mode_flag; + __eeh_mark_slot (dn->child, mode_flag); +} + +static void __eeh_clear_slot (struct device_node *dn, int mode_flag) +{ + while (dn) { + if (PCI_DN(dn)) { + PCI_DN(dn)->eeh_mode &= ~mode_flag; + PCI_DN(dn)->eeh_check_count = 0; + if (dn->child) + __eeh_clear_slot (dn->child, mode_flag); + } + dn = dn->sibling; + } +} + +void eeh_clear_slot (struct device_node *dn, int mode_flag) +{ + unsigned long flags; + spin_lock_irqsave(&confirm_error_lock, flags); + dn = find_device_pe (dn); + PCI_DN(dn)->eeh_mode &= ~mode_flag; + PCI_DN(dn)->eeh_check_count = 0; + __eeh_clear_slot (dn->child, mode_flag); + spin_unlock_irqrestore(&confirm_error_lock, flags); +} + +/** + * eeh_dn_check_failure - check if all 1's data is due to EEH slot freeze + * @dn device node + * @dev pci device, if known + * + * Check for an EEH failure for the given device node. 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. This routine + * will query firmware for the EEH status. + * + * Returns 0 if there has not been an EEH error; otherwise returns + * a non-zero value and queues up a slot isolation event notification. + * + * It is safe to call this routine in an interrupt context. + */ +int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) +{ + int ret; + int rets[3]; + unsigned long flags; + struct pci_dn *pdn; + int rc = 0; + + __get_cpu_var(total_mmio_ffs)++; + + if (!eeh_subsystem_enabled) + return 0; + + if (!dn) { + __get_cpu_var(no_dn)++; + return 0; + } + pdn = PCI_DN(dn); + + /* Access to IO BARs might get this far and still not want checking. */ + if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) || + pdn->eeh_mode & EEH_MODE_NOCHECK) { + __get_cpu_var(ignored_check)++; +#ifdef DEBUG + printk ("EEH:ignored check (%x) for %s %s\n", + pdn->eeh_mode, pci_name (dev), dn->full_name); +#endif + return 0; + } + + if (!pdn->eeh_config_addr) { + __get_cpu_var(no_cfg_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. + * Do this checking under a lock; as multiple PCI devices + * in one slot might report errors simultaneously, and we + * only want one error recovery routine running. + */ + spin_lock_irqsave(&confirm_error_lock, flags); + rc = 1; + if (pdn->eeh_mode & EEH_MODE_ISOLATED) { + pdn->eeh_check_count ++; + if (pdn->eeh_check_count >= EEH_MAX_FAILS) { + printk (KERN_ERR "EEH: Device driver ignored %d bad reads, panicing\n", + pdn->eeh_check_count); + dump_stack(); + + /* re-read the slot reset state */ + if (read_slot_reset_state(pdn, rets) != 0) + rets[0] = -1; /* reset state unknown */ + + /* If we are here, then we hit an infinite loop. Stop. */ + panic("EEH: MMIO halt (%d) on device:%s\n", rets[0], pci_name(dev)); + } + goto dn_unlock; + } + + /* + * Now test for an EEH failure. This is VERY expensive. + * Note that the eeh_config_addr may be a parent device + * in the case of a device behind a bridge, or it may be + * function zero of a multi-function device. + * In any case they must share a common PHB. + */ + ret = read_slot_reset_state(pdn, rets); + + /* If the call to firmware failed, punt */ + if (ret != 0) { + printk(KERN_WARNING "EEH: read_slot_reset_state() failed; rc=%d dn=%s\n", + ret, dn->full_name); + __get_cpu_var(false_positives)++; + rc = 0; + goto dn_unlock; + } + + /* If EEH is not supported on this device, punt. */ + if (rets[1] != 1) { + printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n", + ret, dn->full_name); + __get_cpu_var(false_positives)++; + rc = 0; + goto dn_unlock; + } + + /* If not the kind of error we know about, punt. */ + if (rets[0] != 2 && rets[0] != 4 && rets[0] != 5) { + __get_cpu_var(false_positives)++; + rc = 0; + goto dn_unlock; + } + + /* Note that config-io to empty slots may fail; + * we recognize empty because they don't have children. */ + if ((rets[0] == 5) && (dn->child == NULL)) { + __get_cpu_var(false_positives)++; + rc = 0; + goto dn_unlock; + } + + __get_cpu_var(slot_resets)++; + + /* Avoid repeated reports of this failure, including problems + * with other functions on this device, and functions under + * bridges. */ + eeh_mark_slot (dn, EEH_MODE_ISOLATED); + spin_unlock_irqrestore(&confirm_error_lock, flags); + + eeh_send_failure_event (dn, dev, rets[0], rets[2]); + + /* Most EEH events are due to device driver bugs. Having + * a stack trace will help the device-driver authors figure + * out what happened. So print that out. */ + if (rets[0] != 5) dump_stack(); + return 1; + +dn_unlock: + spin_unlock_irqrestore(&confirm_error_lock, flags); + return rc; +} + +EXPORT_SYMBOL_GPL(eeh_dn_check_failure); + +/** + * eeh_check_failure - check if all 1's data is due to EEH slot freeze + * @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. 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 + * will query firmware for the EEH status. + * + * 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; + struct pci_dev *dev; + struct device_node *dn; + + /* 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) { + __get_cpu_var(no_device)++; + return val; + } + + dn = pci_device_to_OF_node(dev); + eeh_dn_check_failure (dn, dev); + + pci_dev_put(dev); + return val; +} + +EXPORT_SYMBOL(eeh_check_failure); + +/* ------------------------------------------------------------- */ +/* The code below deals with error recovery */ + +/** Return negative value if a permanent error, else return + * a number of milliseconds to wait until the PCI slot is + * ready to be used. + */ +static int +eeh_slot_availability(struct pci_dn *pdn) +{ + int rc; + int rets[3]; + + rc = read_slot_reset_state(pdn, rets); + + if (rc) return rc; + + if (rets[1] == 0) return -1; /* EEH is not supported */ + if (rets[0] == 0) return 0; /* Oll Korrect */ + if (rets[0] == 5) { + if (rets[2] == 0) return -1; /* permanently unavailable */ + return rets[2]; /* number of millisecs to wait */ + } + return -1; +} + +/** rtas_pci_slot_reset raises/lowers the pci #RST line + * state: 1/0 to raise/lower the #RST + * + * Clear the EEH-frozen condition on a slot. This routine + * asserts the PCI #RST line if the 'state' argument is '1', + * and drops the #RST line if 'state is '0'. This routine is + * safe to call in an interrupt context. + * + */ + +static void +rtas_pci_slot_reset(struct pci_dn *pdn, int state) +{ + int rc; + + BUG_ON (pdn==NULL); + + if (!pdn->phb) { + printk (KERN_WARNING "EEH: in slot reset, device node %s has no phb\n", + pdn->node->full_name); + return; + } + + rc = rtas_call(ibm_set_slot_reset,4,1, NULL, + pdn->eeh_config_addr, + BUID_HI(pdn->phb->buid), + BUID_LO(pdn->phb->buid), + state); + if (rc) { + printk (KERN_WARNING "EEH: Unable to reset the failed slot, (%d) #RST=%d dn=%s\n", + rc, state, pdn->node->full_name); + return; + } +} + +/** rtas_set_slot_reset -- assert the pci #RST line for 1/4 second + * dn -- device node to be reset. + */ + +void +rtas_set_slot_reset(struct pci_dn *pdn) +{ + int i, rc; + + rtas_pci_slot_reset (pdn, 1); + + /* The PCI bus requires that the reset be held high for at least + * a 100 milliseconds. We wait a bit longer 'just in case'. */ + +#define PCI_BUS_RST_HOLD_TIME_MSEC 250 + msleep (PCI_BUS_RST_HOLD_TIME_MSEC); + + /* We might get hit with another EEH freeze as soon as the + * pci slot reset line is dropped. Make sure we don't miss + * these, and clear the flag now. */ + eeh_clear_slot (pdn->node, EEH_MODE_ISOLATED); + + rtas_pci_slot_reset (pdn, 0); + + /* After a PCI slot has been reset, the PCI Express spec requires + * a 1.5 second idle time for the bus to stabilize, before starting + * up traffic. */ +#define PCI_BUS_SETTLE_TIME_MSEC 1800 + msleep (PCI_BUS_SETTLE_TIME_MSEC); + + /* Now double check with the firmware to make sure the device is + * ready to be used; if not, wait for recovery. */ + for (i=0; i<10; i++) { + rc = eeh_slot_availability (pdn); + if (rc <= 0) break; + + msleep (rc+100); + } +} + +/* ------------------------------------------------------- */ +/** 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. + */ + +/** + * __restore_bars - Restore the Base Address Registers + * Loads the PCI configuration space base address registers, + * the expansion ROM base address, the latency timer, and etc. + * from the saved values in the device node. + */ +static inline void __restore_bars (struct pci_dn *pdn) +{ + int i; + + if (NULL==pdn->phb) return; + for (i=4; i<10; i++) { + rtas_write_config(pdn, i*4, 4, pdn->config_space[i]); + } + + /* 12 == Expansion ROM Address */ + rtas_write_config(pdn, 12*4, 4, pdn->config_space[12]); + +#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) +#define SAVED_BYTE(OFF) (((u8 *)(pdn->config_space))[BYTE_SWAP(OFF)]) + + rtas_write_config (pdn, PCI_CACHE_LINE_SIZE, 1, + SAVED_BYTE(PCI_CACHE_LINE_SIZE)); + + rtas_write_config (pdn, PCI_LATENCY_TIMER, 1, + SAVED_BYTE(PCI_LATENCY_TIMER)); + + /* max latency, min grant, interrupt pin and line */ + rtas_write_config(pdn, 15*4, 4, pdn->config_space[15]); +} + +/** + * eeh_restore_bars - restore the PCI config space info + * + * This routine performs a recursive walk to the children + * of this device as well. + */ +void eeh_restore_bars(struct pci_dn *pdn) +{ + struct device_node *dn; + if (!pdn) + return; + + if (! pdn->eeh_is_bridge) + __restore_bars (pdn); + + dn = pdn->node->child; + while (dn) { + eeh_restore_bars (PCI_DN(dn)); + dn = dn->sibling; + } +} + +/** + * eeh_save_bars - save device bars + * + * Save the values of the device bars. Unlike the restore + * routine, this routine is *not* recursive. This is because + * PCI devices are added individuallly; but, for the restore, + * an entire slot is reset at a time. + */ +static void eeh_save_bars(struct pci_dev * pdev, struct pci_dn *pdn) +{ + int i; + + if (!pdev || !pdn ) + return; + + for (i = 0; i < 16; i++) + pci_read_config_dword(pdev, i * 4, &pdn->config_space[i]); + + if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) + pdn->eeh_is_bridge = 1; +} + +void +rtas_configure_bridge(struct pci_dn *pdn) +{ + int token = rtas_token ("ibm,configure-bridge"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return; + rc = rtas_call(token,3,1, NULL, + pdn->eeh_config_addr, + BUID_HI(pdn->phb->buid), + BUID_LO(pdn->phb->buid)); + if (rc) { + printk (KERN_WARNING "EEH: Unable to configure device bridge (%d) for %s\n", + rc, pdn->node->full_name); + } +} + +/* ------------------------------------------------------------- */ +/* 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. + */ + +#define EEH_ENABLE 1 + +struct eeh_early_enable_info { + unsigned int buid_hi; + unsigned int buid_lo; +}; + +/* Enable eeh for the given device node. */ +static void *early_enable_eeh(struct device_node *dn, void *data) +{ + struct eeh_early_enable_info *info = data; + int ret; + char *status = get_property(dn, "status", NULL); + u32 *class_code = (u32 *)get_property(dn, "class-code", NULL); + u32 *vendor_id = (u32 *)get_property(dn, "vendor-id", NULL); + u32 *device_id = (u32 *)get_property(dn, "device-id", NULL); + u32 *regs; + int enable; + struct pci_dn *pdn = PCI_DN(dn); + + pdn->eeh_mode = 0; + pdn->eeh_check_count = 0; + pdn->eeh_freeze_count = 0; + + if (status && strcmp(status, "ok") != 0) + return NULL; /* ignore devices with bad status */ + + /* Ignore bad nodes. */ + if (!class_code || !vendor_id || !device_id) + return NULL; + + /* There is nothing to check on PCI to ISA bridges */ + if (dn->type && !strcmp(dn->type, "isa")) { + pdn->eeh_mode |= EEH_MODE_NOCHECK; + return NULL; + } + + /* + * Now decide if we are going to "Disable" EEH checking + * for this device. We still run with the EEH hardware active, + * but we won't be checking for ff's. This means a driver + * could return bad data (very bad!), an interrupt handler could + * hang waiting on status bits that won't change, etc. + * But there are a few cases like display devices that make sense. + */ + enable = 1; /* i.e. we will do checking */ + if ((*class_code >> 16) == PCI_BASE_CLASS_DISPLAY) + enable = 0; + + if (!enable) + pdn->eeh_mode |= EEH_MODE_NOCHECK; + + /* Ok... see if this device supports EEH. Some do, some don't, + * and the only way to find out is to check each and every one. */ + regs = (u32 *)get_property(dn, "reg", NULL); + if (regs) { + /* First register entry is addr (00BBSS00) */ + /* Try to enable eeh */ + ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL, + regs[0], info->buid_hi, info->buid_lo, + EEH_ENABLE); + + if (ret == 0) { + eeh_subsystem_enabled = 1; + pdn->eeh_mode |= EEH_MODE_SUPPORTED; + pdn->eeh_config_addr = regs[0]; +#ifdef DEBUG + printk(KERN_DEBUG "EEH: %s: eeh enabled\n", dn->full_name); +#endif + } else { + + /* This device doesn't support EEH, but it may have an + * EEH parent, in which case we mark it as supported. */ + if (dn->parent && PCI_DN(dn->parent) + && (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { + /* Parent supports EEH. */ + pdn->eeh_mode |= EEH_MODE_SUPPORTED; + pdn->eeh_config_addr = PCI_DN(dn->parent)->eeh_config_addr; + return NULL; + } + } + } else { + printk(KERN_WARNING "EEH: %s: unable to get reg property.\n", + dn->full_name); + } + + return NULL; +} + +/* + * Initialize EEH by trying to enable it for all of the adapters in the system. + * As a side effect we can determine here if eeh is supported at all. + * Note that we leave EEH on so failed config cycles won't cause a machine + * check. If a user turns off EEH for a particular adapter they are really + * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't + * grant access to a slot if EEH isn't enabled, and so we always enable + * EEH for all slots/all devices. + * + * The eeh-force-off option disables EEH checking globally, for all slots. + * Even if force-off is set, the EEH hardware is still enabled, so that + * newer systems can boot. + */ +void __init eeh_init(void) +{ + struct device_node *phb, *np; + struct eeh_early_enable_info info; + + spin_lock_init(&confirm_error_lock); + spin_lock_init(&slot_errbuf_lock); + + np = of_find_node_by_path("/rtas"); + if (np == NULL) + return; + + ibm_set_eeh_option = rtas_token("ibm,set-eeh-option"); + ibm_set_slot_reset = rtas_token("ibm,set-slot-reset"); + ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2"); + ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state"); + ibm_slot_error_detail = rtas_token("ibm,slot-error-detail"); + + if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE) + return; + + eeh_error_buf_size = rtas_token("rtas-error-log-max"); + if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) { + eeh_error_buf_size = 1024; + } + if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) { + printk(KERN_WARNING "EEH: rtas-error-log-max is bigger than allocated " + "buffer ! (%d vs %d)", eeh_error_buf_size, RTAS_ERROR_LOG_MAX); + eeh_error_buf_size = RTAS_ERROR_LOG_MAX; + } + + /* Enable EEH for all adapters. Note that eeh requires buid's */ + for (phb = of_find_node_by_name(NULL, "pci"); phb; + phb = of_find_node_by_name(phb, "pci")) { + unsigned long buid; + + buid = get_phb_buid(phb); + if (buid == 0 || PCI_DN(phb) == NULL) + continue; + + info.buid_lo = BUID_LO(buid); + info.buid_hi = BUID_HI(buid); + traverse_pci_devices(phb, early_enable_eeh, &info); + } + + if (eeh_subsystem_enabled) + printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n"); + else + printk(KERN_WARNING "EEH: No capable adapters found\n"); +} + +/** + * eeh_add_device_early - enable EEH for the indicated device_node + * @dn: device node for which to set up EEH + * + * This routine must be used to perform EEH initialization for PCI + * devices that were added after system boot (e.g. hotplug, dlpar). + * This routine must be called before any i/o is performed to the + * adapter (inluding any config-space i/o). + * Whether this actually enables EEH or not for this device depends + * on the CEC architecture, type of the device, on earlier boot + * command-line arguments & etc. + */ +void eeh_add_device_early(struct device_node *dn) +{ + struct pci_controller *phb; + struct eeh_early_enable_info info; + + if (!dn || !PCI_DN(dn)) + return; + phb = PCI_DN(dn)->phb; + if (NULL == phb || 0 == phb->buid) { + printk(KERN_WARNING "EEH: Expected buid but found none for %s\n", + dn->full_name); + dump_stack(); + return; + } + + info.buid_hi = BUID_HI(phb->buid); + info.buid_lo = BUID_LO(phb->buid); + early_enable_eeh(dn, &info); +} +EXPORT_SYMBOL_GPL(eeh_add_device_early); + +/** + * eeh_add_device_late - perform EEH initialization for the indicated pci device + * @dev: pci device for which to set up EEH + * + * This routine must be used to complete EEH initialization for PCI + * devices that were added after system boot (e.g. hotplug, dlpar). + */ +void eeh_add_device_late(struct pci_dev *dev) +{ + struct device_node *dn; + struct pci_dn *pdn; + + if (!dev || !eeh_subsystem_enabled) + return; + +#ifdef DEBUG + printk(KERN_DEBUG "EEH: adding device %s\n", pci_name(dev)); +#endif + + pci_dev_get (dev); + dn = pci_device_to_OF_node(dev); + pdn = PCI_DN(dn); + pdn->pcidev = dev; + + pci_addr_cache_insert_device (dev); + eeh_save_bars(dev, pdn); +} +EXPORT_SYMBOL_GPL(eeh_add_device_late); + +/** + * eeh_remove_device - undo EEH setup for the indicated pci device + * @dev: pci device to be removed + * + * This routine should be when a device is removed from a running + * system (e.g. by hotplug or dlpar). + */ +void eeh_remove_device(struct pci_dev *dev) +{ + struct device_node *dn; + if (!dev || !eeh_subsystem_enabled) + return; + + /* Unregister the device with the EEH/PCI address search system */ +#ifdef DEBUG + printk(KERN_DEBUG "EEH: remove device %s\n", pci_name(dev)); +#endif + pci_addr_cache_remove_device(dev); + + dn = pci_device_to_OF_node(dev); + PCI_DN(dn)->pcidev = NULL; + pci_dev_put (dev); +} +EXPORT_SYMBOL_GPL(eeh_remove_device); + +static int proc_eeh_show(struct seq_file *m, void *v) +{ + unsigned int cpu; + unsigned long ffs = 0, positives = 0, failures = 0; + unsigned long resets = 0; + unsigned long no_dev = 0, no_dn = 0, no_cfg = 0, no_check = 0; + + for_each_cpu(cpu) { + ffs += per_cpu(total_mmio_ffs, cpu); + positives += per_cpu(false_positives, cpu); + failures += per_cpu(ignored_failures, cpu); + resets += per_cpu(slot_resets, cpu); + no_dev += per_cpu(no_device, cpu); + no_dn += per_cpu(no_dn, cpu); + no_cfg += per_cpu(no_cfg_addr, cpu); + no_check += per_cpu(ignored_check, cpu); + } + + if (0 == eeh_subsystem_enabled) { + seq_printf(m, "EEH Subsystem is globally disabled\n"); + seq_printf(m, "eeh_total_mmio_ffs=%ld\n", ffs); + } else { + seq_printf(m, "EEH Subsystem is enabled\n"); + seq_printf(m, + "no device=%ld\n" + "no device node=%ld\n" + "no config address=%ld\n" + "check not wanted=%ld\n" + "eeh_total_mmio_ffs=%ld\n" + "eeh_false_positives=%ld\n" + "eeh_ignored_failures=%ld\n" + "eeh_slot_resets=%ld\n", + no_dev, no_dn, no_cfg, no_check, + ffs, positives, failures, resets); + } + + return 0; +} + +static int proc_eeh_open(struct inode *inode, struct file *file) +{ + return single_open(file, proc_eeh_show, NULL); +} + +static struct file_operations proc_eeh_operations = { + .open = proc_eeh_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init eeh_init_proc(void) +{ + struct proc_dir_entry *e; + + if (platform_is_pseries()) { + e = create_proc_entry("ppc64/eeh", 0, NULL); + if (e) + e->proc_fops = &proc_eeh_operations; + } + + return 0; +} +__initcall(eeh_init_proc); |