/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pci.h" #undef DEBUG #define BUID_HI(buid) ((buid) >> 32) #define BUID_LO(buid) ((buid) & 0xffffffff) #define CONFIG_ADDR(busno, devfn) \ (((((busno) & 0xff) << 8) | ((devfn) & 0xf8)) << 8) /* RTAS tokens */ static int ibm_set_eeh_option; static int ibm_set_slot_reset; static int ibm_read_slot_reset_state; static int ibm_slot_error_detail; static int eeh_subsystem_enabled; /* Buffer for reporting slot-error-detail rtas calls */ static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX]; static spinlock_t slot_errbuf_lock = SPIN_LOCK_UNLOCKED; static int eeh_error_buf_size; /* System monitoring statistics */ 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); /** * 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. * * 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 %s\n", (piar->flags & IORESOURCE_IO) ? "i/o" : "mem", cnt, piar->addr_lo, piar->addr_hi, pci_name(piar->pcidev), pci_pretty_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 (alo < piar->addr_lo) { p = &parent->rb_left; } else if (ahi > 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; 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; 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 %s\n", pci_name(dev), pci_pretty_name(dev)); return; } /* Skip any devices for which EEH is not enabled. */ if (!(dn->eeh_mode & EEH_MODE_SUPPORTED) || dn->eeh_mode & EEH_MODE_NOCHECK) { #ifdef DEBUG printk(KERN_INFO "PCI: skip building address cache for=%s %s\n", pci_name(dev), pci_pretty_name(dev)); #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. */ 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. */ 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 pci_dev *dev = NULL; 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); } #ifdef DEBUG /* Verify tree built up above, echo back the list of addrs. */ pci_addr_cache_print(&pci_io_addr_cache_root); #endif } /** * eeh_token_to_phys - convert EEH address token to phys address * @token i/o token, should be address in the form 0xE.... */ static inline unsigned long eeh_token_to_phys(unsigned long token) { pte_t *ptep; unsigned long pa; ptep = find_linux_pte(ioremap_mm.pgd, token); if (!ptep) return token; pa = pte_pfn(*ptep) << PAGE_SHIFT; return pa | (token & (PAGE_SIZE-1)); } /** * 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 event. This routine * will query firmware for the EEH status. * * Returns 0 if there has not been an EEH error; otherwise returns * an error code. * * 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[2]; unsigned long flags; __get_cpu_var(total_mmio_ffs)++; if (!eeh_subsystem_enabled) return 0; if (!dn) return 0; /* Access to IO BARs might get this far and still not want checking. */ if (!(dn->eeh_mode & EEH_MODE_SUPPORTED) || dn->eeh_mode & EEH_MODE_NOCHECK) { return 0; } if (!dn->eeh_config_addr) { return 0; } /* * 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 = rtas_call(ibm_read_slot_reset_state, 3, 3, rets, dn->eeh_config_addr, BUID_HI(dn->phb->buid), BUID_LO(dn->phb->buid)); if (ret == 0 && rets[1] == 1 && (rets[0] == 2 || rets[0] == 4)) { int log_event; spin_lock_irqsave(&slot_errbuf_lock, flags); memset(slot_errbuf, 0, eeh_error_buf_size); log_event = 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 (log_event == 0) log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 1 /* Fatal */); 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); WARN_ON(1); /* * XXX We should create a separate sysctl for this. * * Since the panic_on_oops sysctl is used to halt * the system in light of potential corruption, we * can use it here. */ if (panic_on_oops) { panic("EEH: MMIO failure (%d) on device: %s %s\n", rets[0], dn->name, dn->full_name); } else { __get_cpu_var(ignored_failures)++; } } else { __get_cpu_var(false_positives)++; } return 0; } EXPORT_SYMBOL(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. * 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) 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); 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; dn->eeh_mode = 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")) { dn->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) dn->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; dn->eeh_mode |= EEH_MODE_SUPPORTED; dn->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 && (dn->parent->eeh_mode & EEH_MODE_SUPPORTED)) { /* Parent supports EEH. */ dn->eeh_mode |= EEH_MODE_SUPPORTED; dn->eeh_config_addr = 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; init_pci_config_tokens(); 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_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) 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 || !eeh_subsystem_enabled) return; phb = dn->phb; if (NULL == phb || 0 == phb->buid) { printk(KERN_WARNING "EEH: Expected buid but found none\n"); return; } info.buid_hi = BUID_HI(phb->buid); info.buid_lo = BUID_LO(phb->buid); early_enable_eeh(dn, &info); } EXPORT_SYMBOL(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) { if (!dev || !eeh_subsystem_enabled) return; #ifdef DEBUG printk(KERN_DEBUG "EEH: adding device %s %s\n", pci_name(dev), pci_pretty_name(dev)); #endif pci_addr_cache_insert_device (dev); } EXPORT_SYMBOL(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) { 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 %s\n", pci_name(dev), pci_pretty_name(dev)); #endif pci_addr_cache_remove_device(dev); } EXPORT_SYMBOL(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; for_each_cpu(cpu) { ffs += per_cpu(total_mmio_ffs, cpu); positives += per_cpu(false_positives, cpu); failures += per_cpu(ignored_failures, 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, "eeh_total_mmio_ffs=%ld\n" "eeh_false_positives=%ld\n" "eeh_ignored_failures=%ld\n", ffs, positives, failures); } 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 (systemcfg->platform & PLATFORM_PSERIES) { e = create_proc_entry("ppc64/eeh", 0, NULL); if (e) e->proc_fops = &proc_eeh_operations; } return 0; } __initcall(eeh_init_proc);