diff options
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 942 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_cache.c | 318 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_dev.c | 112 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_driver.c | 551 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_event.c | 142 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_pe.c | 653 | ||||
| -rw-r--r-- | arch/powerpc/kernel/eeh_sysfs.c | 74 | ||||
| -rw-r--r-- | arch/powerpc/kernel/pci-hotplug.c | 111 |
9 files changed, 2906 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index f960a7944553..a8619bfe879e 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -58,6 +58,8 @@ obj-$(CONFIG_RTAS_PROC) += rtas-proc.o obj-$(CONFIG_LPARCFG) += lparcfg.o obj-$(CONFIG_IBMVIO) += vio.o obj-$(CONFIG_IBMEBUS) += ibmebus.o +obj-$(CONFIG_EEH) += eeh.o eeh_pe.o eeh_dev.o eeh_cache.o \ + eeh_driver.o eeh_event.o eeh_sysfs.o obj-$(CONFIG_GENERIC_TBSYNC) += smp-tbsync.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_FA_DUMP) += fadump.o @@ -100,7 +102,7 @@ obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o -pci64-$(CONFIG_PPC64) += pci_dn.o isa-bridge.o +pci64-$(CONFIG_PPC64) += pci_dn.o pci-hotplug.o isa-bridge.o obj-$(CONFIG_PCI) += pci_$(CONFIG_WORD_SIZE).o $(pci64-y) \ pci-common.o pci_of_scan.o obj-$(CONFIG_PCI_MSI) += msi.o diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c new file mode 100644 index 000000000000..8a8345193083 --- /dev/null +++ b/arch/powerpc/kernel/eeh.c @@ -0,0 +1,942 @@ +/* + * Copyright IBM Corporation 2001, 2005, 2006 + * Copyright Dave Engebretsen & Todd Inglett 2001 + * Copyright Linas Vepstas 2005, 2006 + * Copyright 2001-2012 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 + * + * Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com> + */ + +#include <linux/delay.h> +#include <linux/sched.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 <linux/export.h> +#include <linux/of.h> + +#include <linux/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> + + +/** 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 occurred (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, it might be broken. + * This sets the threshold for how many read attempts we allow + * before printing an error message. + */ +#define EEH_MAX_FAILS 2100000 + +/* Time to wait for a PCI slot to report status, in milliseconds */ +#define PCI_BUS_RESET_WAIT_MSEC (60*1000) + +/* Platform dependent EEH operations */ +struct eeh_ops *eeh_ops = NULL; + +int eeh_subsystem_enabled; +EXPORT_SYMBOL(eeh_subsystem_enabled); + +/* + * EEH probe mode support. The intention is to support multiple + * platforms for EEH. Some platforms like pSeries do PCI emunation + * based on device tree. However, other platforms like powernv probe + * PCI devices from hardware. The flag is used to distinguish that. + * In addition, struct eeh_ops::probe would be invoked for particular + * OF node or PCI device so that the corresponding PE would be created + * there. + */ +int eeh_probe_mode; + +/* Global EEH mutex */ +DEFINE_MUTEX(eeh_mutex); + +/* Lock to avoid races due to multiple reports of an error */ +static DEFINE_RAW_SPINLOCK(confirm_error_lock); + +/* Buffer for reporting pci register dumps. Its here in BSS, and + * not dynamically alloced, so that it ends up in RMO where RTAS + * can access it. + */ +#define EEH_PCI_REGS_LOG_LEN 4096 +static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN]; + +/* + * The struct is used to maintain the EEH global statistic + * information. Besides, the EEH global statistics will be + * exported to user space through procfs + */ +struct eeh_stats { + u64 no_device; /* PCI device not found */ + u64 no_dn; /* OF node not found */ + u64 no_cfg_addr; /* Config address not found */ + u64 ignored_check; /* EEH check skipped */ + u64 total_mmio_ffs; /* Total EEH checks */ + u64 false_positives; /* Unnecessary EEH checks */ + u64 slot_resets; /* PE reset */ +}; + +static struct eeh_stats eeh_stats; + +#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) + +/** + * eeh_gather_pci_data - Copy assorted PCI config space registers to buff + * @edev: device to report data for + * @buf: point to buffer in which to log + * @len: amount of room in buffer + * + * This routine captures assorted PCI configuration space data, + * and puts them into a buffer for RTAS error logging. + */ +static size_t eeh_gather_pci_data(struct eeh_dev *edev, char * buf, size_t len) +{ + struct device_node *dn = eeh_dev_to_of_node(edev); + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + u32 cfg; + int cap, i; + int n = 0; + + n += scnprintf(buf+n, len-n, "%s\n", dn->full_name); + printk(KERN_WARNING "EEH: of node=%s\n", dn->full_name); + + eeh_ops->read_config(dn, PCI_VENDOR_ID, 4, &cfg); + n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg); + printk(KERN_WARNING "EEH: PCI device/vendor: %08x\n", cfg); + + eeh_ops->read_config(dn, PCI_COMMAND, 4, &cfg); + n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg); + printk(KERN_WARNING "EEH: PCI cmd/status register: %08x\n", cfg); + + if (!dev) { + printk(KERN_WARNING "EEH: no PCI device for this of node\n"); + return n; + } + + /* Gather bridge-specific registers */ + if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) { + eeh_ops->read_config(dn, PCI_SEC_STATUS, 2, &cfg); + n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg); + printk(KERN_WARNING "EEH: Bridge secondary status: %04x\n", cfg); + + eeh_ops->read_config(dn, PCI_BRIDGE_CONTROL, 2, &cfg); + n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg); + printk(KERN_WARNING "EEH: Bridge control: %04x\n", cfg); + } + + /* Dump out the PCI-X command and status regs */ + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (cap) { + eeh_ops->read_config(dn, cap, 4, &cfg); + n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg); + printk(KERN_WARNING "EEH: PCI-X cmd: %08x\n", cfg); + + eeh_ops->read_config(dn, cap+4, 4, &cfg); + n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg); + printk(KERN_WARNING "EEH: PCI-X status: %08x\n", cfg); + } + + /* If PCI-E capable, dump PCI-E cap 10, and the AER */ + cap = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (cap) { + n += scnprintf(buf+n, len-n, "pci-e cap10:\n"); + printk(KERN_WARNING + "EEH: PCI-E capabilities and status follow:\n"); + + for (i=0; i<=8; i++) { + eeh_ops->read_config(dn, cap+4*i, 4, &cfg); + n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); + printk(KERN_WARNING "EEH: PCI-E %02x: %08x\n", i, cfg); + } + + cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); + if (cap) { + n += scnprintf(buf+n, len-n, "pci-e AER:\n"); + printk(KERN_WARNING + "EEH: PCI-E AER capability register set follows:\n"); + + for (i=0; i<14; i++) { + eeh_ops->read_config(dn, cap+4*i, 4, &cfg); + n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); + printk(KERN_WARNING "EEH: PCI-E AER %02x: %08x\n", i, cfg); + } + } + } + + return n; +} + +/** + * eeh_slot_error_detail - Generate combined log including driver log and error log + * @pe: EEH PE + * @severity: temporary or permanent error log + * + * This routine should be called to generate the combined log, which + * is comprised of driver log and error log. The driver log is figured + * out from the config space of the corresponding PCI device, while + * the error log is fetched through platform dependent function call. + */ +void eeh_slot_error_detail(struct eeh_pe *pe, int severity) +{ + size_t loglen = 0; + struct eeh_dev *edev; + + eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + eeh_ops->configure_bridge(pe); + eeh_pe_restore_bars(pe); + + pci_regs_buf[0] = 0; + eeh_pe_for_each_dev(pe, edev) { + loglen += eeh_gather_pci_data(edev, pci_regs_buf, + EEH_PCI_REGS_LOG_LEN); + } + + eeh_ops->get_log(pe, severity, pci_regs_buf, loglen); +} + +/** + * eeh_token_to_phys - Convert EEH address token to phys address + * @token: I/O token, should be address in the form 0xA.... + * + * This routine should be called to convert virtual I/O address + * to physical one. + */ +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)); +} + +/** + * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze + * @edev: eeh device + * + * 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_dev_check_failure(struct eeh_dev *edev) +{ + int ret; + unsigned long flags; + struct device_node *dn; + struct pci_dev *dev; + struct eeh_pe *pe; + int rc = 0; + const char *location; + + eeh_stats.total_mmio_ffs++; + + if (!eeh_subsystem_enabled) + return 0; + + if (!edev) { + eeh_stats.no_dn++; + return 0; + } + dn = eeh_dev_to_of_node(edev); + dev = eeh_dev_to_pci_dev(edev); + pe = edev->pe; + + /* Access to IO BARs might get this far and still not want checking. */ + if (!pe) { + eeh_stats.ignored_check++; + pr_debug("EEH: Ignored check for %s %s\n", + eeh_pci_name(dev), dn->full_name); + return 0; + } + + if (!pe->addr && !pe->config_addr) { + eeh_stats.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. + */ + raw_spin_lock_irqsave(&confirm_error_lock, flags); + rc = 1; + if (pe->state & EEH_PE_ISOLATED) { + pe->check_count++; + if (pe->check_count % EEH_MAX_FAILS == 0) { + location = of_get_property(dn, "ibm,loc-code", NULL); + printk(KERN_ERR "EEH: %d reads ignored for recovering device at " + "location=%s driver=%s pci addr=%s\n", + pe->check_count, location, + eeh_driver_name(dev), eeh_pci_name(dev)); + printk(KERN_ERR "EEH: Might be infinite loop in %s driver\n", + eeh_driver_name(dev)); + dump_stack(); + } + 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 = eeh_ops->get_state(pe, NULL); + + /* Note that config-io to empty slots may fail; + * they are empty when they don't have children. + * We will punt with the following conditions: Failure to get + * PE's state, EEH not support and Permanently unavailable + * state, PE is in good state. + */ + if ((ret < 0) || + (ret == EEH_STATE_NOT_SUPPORT) || + (ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) == + (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) { + eeh_stats.false_positives++; + pe->false_positives++; + rc = 0; + goto dn_unlock; + } + + eeh_stats.slot_resets++; + + /* Avoid repeated reports of this failure, including problems + * with other functions on this device, and functions under + * bridges. + */ + eeh_pe_state_mark(pe, EEH_PE_ISOLATED); + raw_spin_unlock_irqrestore(&confirm_error_lock, flags); + + eeh_send_failure_event(pe); + + /* 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. + */ + WARN(1, "EEH: failure detected\n"); + return 1; + +dn_unlock: + raw_spin_unlock_irqrestore(&confirm_error_lock, flags); + return rc; +} + +EXPORT_SYMBOL_GPL(eeh_dev_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 eeh_dev *edev; + + /* Finding the phys addr + pci device; this is pretty quick. */ + addr = eeh_token_to_phys((unsigned long __force) token); + edev = eeh_addr_cache_get_dev(addr); + if (!edev) { + eeh_stats.no_device++; + return val; + } + + eeh_dev_check_failure(edev); + + pci_dev_put(eeh_dev_to_pci_dev(edev)); + return val; +} + +EXPORT_SYMBOL(eeh_check_failure); + + +/** + * eeh_pci_enable - Enable MMIO or DMA transfers for this slot + * @pe: EEH PE + * + * This routine should be called to reenable frozen MMIO or DMA + * so that it would work correctly again. It's useful while doing + * recovery or log collection on the indicated device. + */ +int eeh_pci_enable(struct eeh_pe *pe, int function) +{ + int rc; + + rc = eeh_ops->set_option(pe, function); + if (rc) + pr_warning("%s: Unexpected state change %d on PHB#%d-PE#%x, err=%d\n", + __func__, function, pe->phb->global_number, pe->addr, rc); + + rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc > 0 && (rc & EEH_STATE_MMIO_ENABLED) && + (function == EEH_OPT_THAW_MMIO)) + return 0; + + return rc; +} + +/** + * pcibios_set_pcie_slot_reset - Set PCI-E reset state + * @dev: pci device struct + * @state: reset state to enter + * + * Return value: + * 0 if success + */ +int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +{ + struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); + struct eeh_pe *pe = edev->pe; + + if (!pe) { + pr_err("%s: No PE found on PCI device %s\n", + __func__, pci_name(dev)); + return -EINVAL; + } + + switch (state) { + case pcie_deassert_reset: + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); + break; + case pcie_hot_reset: + eeh_ops->reset(pe, EEH_RESET_HOT); + break; + case pcie_warm_reset: + eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); + break; + default: + return -EINVAL; + }; + + return 0; +} + +/** + * eeh_set_pe_freset - Check the required reset for the indicated device + * @data: EEH device + * @flag: return value + * + * Each device might have its preferred reset type: fundamental or + * hot reset. The routine is used to collected the information for + * the indicated device and its children so that the bunch of the + * devices could be reset properly. + */ +static void *eeh_set_dev_freset(void *data, void *flag) +{ + struct pci_dev *dev; + unsigned int *freset = (unsigned int *)flag; + struct eeh_dev *edev = (struct eeh_dev *)data; + + dev = eeh_dev_to_pci_dev(edev); + if (dev) + *freset |= dev->needs_freset; + + return NULL; +} + +/** + * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second + * @pe: EEH PE + * + * Assert the PCI #RST line for 1/4 second. + */ +static void eeh_reset_pe_once(struct eeh_pe *pe) +{ + unsigned int freset = 0; + + /* Determine type of EEH reset required for + * Partitionable Endpoint, a hot-reset (1) + * or a fundamental reset (3). + * A fundamental reset required by any device under + * Partitionable Endpoint trumps hot-reset. + */ + eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); + + if (freset) + eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); + else + eeh_ops->reset(pe, EEH_RESET_HOT); + + /* 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_pe_state_clear(pe, EEH_PE_ISOLATED); + + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); + + /* 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); +} + +/** + * eeh_reset_pe - Reset the indicated PE + * @pe: EEH PE + * + * This routine should be called to reset indicated device, including + * PE. A PE might include multiple PCI devices and sometimes PCI bridges + * might be involved as well. + */ +int eeh_reset_pe(struct eeh_pe *pe) +{ + int i, rc; + + /* Take three shots at resetting the bus */ + for (i=0; i<3; i++) { + eeh_reset_pe_once(pe); + + rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc == (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) + return 0; + + if (rc < 0) { + pr_err("%s: Unrecoverable slot failure on PHB#%d-PE#%x", + __func__, pe->phb->global_number, pe->addr); + return -1; + } + pr_err("EEH: bus reset %d failed on PHB#%d-PE#%x, rc=%d\n", + i+1, pe->phb->global_number, pe->addr, rc); + } + + return -1; +} + +/** + * eeh_save_bars - Save device bars + * @edev: PCI device associated EEH device + * + * Save the values of the device bars. Unlike the restore + * routine, this routine is *not* recursive. This is because + * PCI devices are added individually; but, for the restore, + * an entire slot is reset at a time. + */ +void eeh_save_bars(struct eeh_dev *edev) +{ + int i; + struct device_node *dn; + + if (!edev) + return; + dn = eeh_dev_to_of_node(edev); + + for (i = 0; i < 16; i++) + eeh_ops->read_config(dn, i * 4, 4, &edev->config_space[i]); +} + +/** + * eeh_ops_register - Register platform dependent EEH operations + * @ops: platform dependent EEH operations + * + * Register the platform dependent EEH operation callback + * functions. The platform should call this function before + * any other EEH operations. + */ +int __init eeh_ops_register(struct eeh_ops *ops) +{ + if (!ops->name) { + pr_warning("%s: Invalid EEH ops name for %p\n", + __func__, ops); + return -EINVAL; + } + + if (eeh_ops && eeh_ops != ops) { + pr_warning("%s: EEH ops of platform %s already existing (%s)\n", + __func__, eeh_ops->name, ops->name); + return -EEXIST; + } + + eeh_ops = ops; + + return 0; +} + +/** + * eeh_ops_unregister - Unreigster platform dependent EEH operations + * @name: name of EEH platform operations + * + * Unregister the platform dependent EEH operation callback + * functions. + */ +int __exit eeh_ops_unregister(const char *name) +{ + if (!name || !strlen(name)) { + pr_warning("%s: Invalid EEH ops name\n", + __func__); + return -EINVAL; + } + + if (eeh_ops && !strcmp(eeh_ops->name, name)) { + eeh_ops = NULL; + return 0; + } + + return -EEXIST; +} + +/** + * eeh_init - EEH initialization + * + * 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. + */ +static int __init eeh_init(void) +{ + struct pci_controller *hose, *tmp; + struct device_node *phb; + int ret; + + /* call platform initialization function */ + if (!eeh_ops) { + pr_warning("%s: Platform EEH operation not found\n", + __func__); + return -EEXIST; + } else if ((ret = eeh_ops->init())) { + pr_warning("%s: Failed to call platform init function (%d)\n", + __func__, ret); + return ret; + } + + raw_spin_lock_init(&confirm_error_lock); + + /* Enable EEH for all adapters */ + if (eeh_probe_mode_devtree()) { + list_for_each_entry_safe(hose, tmp, + &hose_list, list_node) { + phb = hose->dn; + traverse_pci_devices(phb, eeh_ops->of_probe, NULL); + } + } + + if (eeh_subsystem_enabled) + pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n"); + else + pr_warning("EEH: No capable adapters found\n"); + + return ret; +} + +core_initcall_sync(eeh_init); + +/** + * 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. + */ +static void eeh_add_device_early(struct device_node *dn) +{ + struct pci_controller *phb; + + if (!of_node_to_eeh_dev(dn)) + return; + phb = of_node_to_eeh_dev(dn)->phb; + + /* USB Bus children of PCI devices will not have BUID's */ + if (NULL == phb || 0 == phb->buid) + return; + + /* FIXME: hotplug support on POWERNV */ + eeh_ops->of_probe(dn, NULL); +} + +/** + * eeh_add_device_tree_early - Enable EEH for the indicated device + * @dn: device node + * + * This routine must be used to perform EEH initialization for the + * indicated PCI device that was added after system boot (e.g. + * hotplug, dlpar). + */ +void eeh_add_device_tree_early(struct device_node *dn) +{ + struct device_node *sib; + + for_each_child_of_node(dn, sib) + eeh_add_device_tree_early(sib); + eeh_add_device_early(dn); +} +EXPORT_SYMBOL_GPL(eeh_add_device_tree_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). + */ +static void eeh_add_device_late(struct pci_dev *dev) +{ + struct device_node *dn; + struct eeh_dev *edev; + + if (!dev || !eeh_subsystem_enabled) + return; + + pr_debug("EEH: Adding device %s\n", pci_name(dev)); + + dn = pci_device_to_OF_node(dev); + edev = of_node_to_eeh_dev(dn); + if (edev->pdev == dev) { + pr_debug("EEH: Already referenced !\n"); + return; + } + WARN_ON(edev->pdev); + + pci_dev_get(dev); + edev->pdev = dev; + dev->dev.archdata.edev = edev; + + eeh_addr_cache_insert_dev(dev); +} + +/** + * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus + * @bus: PCI bus + * + * This routine must be used to perform EEH initialization for PCI + * devices which are attached to the indicated PCI bus. The PCI bus + * is added after system boot through hotplug or dlpar. + */ +void eeh_add_device_tree_late(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 (subbus) + eeh_add_device_tree_late(subbus); + } + } +} +EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); + +/** + * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus + * @bus: PCI bus + * + * This routine must be used to add EEH sysfs files for PCI + * devices which are attached to the indicated PCI bus. The PCI bus + * is added after system boot through hotplug or dlpar. + */ +void eeh_add_sysfs_files(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + eeh_sysfs_add_device(dev); + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + struct pci_bus *subbus = dev->subordinate; + if (subbus) + eeh_add_sysfs_files(subbus); + } + } +} +EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); + +/** + * eeh_remove_device - Undo EEH setup for the indicated pci device + * @dev: pci device to be removed + * @purge_pe: remove the PE or not + * + * This routine should be called when a device is removed from + * a running system (e.g. by hotplug or dlpar). It unregisters + * the PCI device from the EEH subsystem. I/O errors affecting + * this device will no longer be detected after this call; thus, + * i/o errors affecting this slot may leave this device unusable. + */ +static void eeh_remove_device(struct pci_dev *dev, int purge_pe) +{ + struct eeh_dev *edev; + + if (!dev || !eeh_subsystem_enabled) + return; + edev = pci_dev_to_eeh_dev(dev); + + /* Unregister the device with the EEH/PCI address search system */ + pr_debug("EEH: Removing device %s\n", pci_name(dev)); + + if (!edev || !edev->pdev) { + pr_debug("EEH: Not referenced !\n"); + return; + } + edev->pdev = NULL; + dev->dev.archdata.edev = NULL; + pci_dev_put(dev); + + eeh_rmv_from_parent_pe(edev, purge_pe); + eeh_addr_cache_rmv_dev(dev); + eeh_sysfs_remove_device(dev); +} + +/** + * eeh_remove_bus_device - Undo EEH setup for the indicated PCI device + * @dev: PCI device + * @purge_pe: remove the corresponding PE or not + * + * This routine must be called when a device is removed from the + * running system through hotplug or dlpar. The corresponding + * PCI address cache will be removed. + */ +void eeh_remove_bus_device(struct pci_dev *dev, int purge_pe) +{ + struct pci_bus *bus = dev->subordinate; + struct pci_dev *child, *tmp; + + eeh_remove_device(dev, purge_pe); + + if (bus && dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + list_for_each_entry_safe(child, tmp, &bus->devices, bus_list) + eeh_remove_bus_device(child, purge_pe); + } +} +EXPORT_SYMBOL_GPL(eeh_remove_bus_device); + +static int proc_eeh_show(struct seq_file *m, void *v) +{ + if (0 == eeh_subsystem_enabled) { + seq_printf(m, "EEH Subsystem is globally disabled\n"); + seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs); + } else { + seq_printf(m, "EEH Subsystem is enabled\n"); + seq_printf(m, + "no device=%llu\n" + "no device node=%llu\n" + "no config address=%llu\n" + "check not wanted=%llu\n" + "eeh_total_mmio_ffs=%llu\n" + "eeh_false_positives=%llu\n" + "eeh_slot_resets=%llu\n", + eeh_stats.no_device, + eeh_stats.no_dn, + eeh_stats.no_cfg_addr, + eeh_stats.ignored_check, + eeh_stats.total_mmio_ffs, + eeh_stats.false_positives, + eeh_stats.slot_resets); + } + + return 0; +} + +static int proc_eeh_open(struct inode *inode, struct file *file) +{ + return single_open(file, proc_eeh_show, NULL); +} + +static const 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) +{ + if (machine_is(pseries)) + proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations); + return 0; +} +__initcall(eeh_init_proc); diff --git a/arch/powerpc/kernel/eeh_cache.c b/arch/powerpc/kernel/eeh_cache.c new file mode 100644 index 000000000000..1d5d9a6ba740 --- /dev/null +++ b/arch/powerpc/kernel/eeh_cache.c @@ -0,0 +1,318 @@ +/* + * PCI address cache; allows the lookup of PCI devices based on I/O address + * + * Copyright IBM Corporation 2004 + * Copyright Linas Vepstas <linas@austin.ibm.com> 2004 + * + * 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/list.h> +#include <linux/pci.h> +#include <linux/rbtree.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/atomic.h> +#include <asm/pci-bridge.h> +#include <asm/ppc-pci.h> + + +/** + * 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 eeh_dev *edev; + 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 eeh_dev *__eeh_addr_cache_get_device(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->edev; + } + } + } + + return NULL; +} + +/** + * eeh_addr_cache_get_dev - 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. + */ +struct eeh_dev *eeh_addr_cache_get_dev(unsigned long addr) +{ + struct eeh_dev *edev; + unsigned long flags; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + edev = __eeh_addr_cache_get_device(addr); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); + return edev; +} + +#ifdef DEBUG +/* + * Handy-dandy debug print routine, does nothing more + * than print out the contents of our addr cache. + */ +static void eeh_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); + pr_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 * +eeh_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) { + pr_warning("PIAR: overlapping address range\n"); + } + return piar; + } + } + piar = kzalloc(sizeof(struct pci_io_addr_range), GFP_ATOMIC); + if (!piar) + return NULL; + + pci_dev_get(dev); + piar->addr_lo = alo; + piar->addr_hi = ahi; + piar->edev = pci_dev_to_eeh_dev(dev); + piar->pcidev = dev; + piar->flags = flags; + +#ifdef DEBUG + pr_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 __eeh_addr_cache_insert_dev(struct pci_dev *dev) +{ + struct device_node *dn; + struct eeh_dev *edev; + int i; + + dn = pci_device_to_OF_node(dev); + if (!dn) { + pr_warning("PCI: no pci dn found for dev=%s\n", pci_name(dev)); + return; + } + + edev = of_node_to_eeh_dev(dn); + if (!edev) { + pr_warning("PCI: no EEH dev found for dn=%s\n", + dn->full_name); + return; + } + + /* Skip any devices for which EEH is not enabled. */ + if (!edev->pe) { +#ifdef DEBUG + pr_info("PCI: skip building address cache for=%s - %s\n", + pci_name(dev), dn->full_name); +#endif + return; + } + + /* 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; + eeh_addr_cache_insert(dev, start, end, flags); + } +} + +/** + * eeh_addr_cache_insert_dev - 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 eeh_addr_cache_insert_dev(struct pci_dev *dev) +{ + unsigned long flags; + + /* Ignore PCI bridges */ + if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE) + return; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + __eeh_addr_cache_insert_dev(dev); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); +} + +static inline void __eeh_addr_cache_rmv_dev(struct pci_dev *dev) +{ + struct rb_node *n; + +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); + pci_dev_put(piar->pcidev); + kfree(piar); + goto restart; + } + n = rb_next(n); + } +} + +/** + * eeh_addr_cache_rmv_dev - 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 eeh_addr_cache_rmv_dev(struct pci_dev *dev) +{ + unsigned long flags; + + spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags); + __eeh_addr_cache_rmv_dev(dev); + spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags); +} + +/** + * eeh_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 scanned for devices (after all device resources are known). + */ +void __init eeh_addr_cache_build(void) +{ + struct device_node *dn; + struct eeh_dev *edev; + struct pci_dev *dev = NULL; + + spin_lock_init(&pci_io_addr_cache_root.piar_lock); + + for_each_pci_dev(dev) { + eeh_addr_cache_insert_dev(dev); + + dn = pci_device_to_OF_node(dev); + if (!dn) + continue; + + edev = of_node_to_eeh_dev(dn); + if (!edev) + continue; + + pci_dev_get(dev); /* matching put is in eeh_remove_device() */ + dev->dev.archdata.edev = edev; + edev->pdev = dev; + + eeh_sysfs_add_device(dev); + } + +#ifdef DEBUG + /* Verify tree built up above, echo back the list of addrs. */ + eeh_addr_cache_print(&pci_io_addr_cache_root); +#endif +} diff --git a/arch/powerpc/kernel/eeh_dev.c b/arch/powerpc/kernel/eeh_dev.c new file mode 100644 index 000000000000..1efa28f5fc54 --- /dev/null +++ b/arch/powerpc/kernel/eeh_dev.c @@ -0,0 +1,112 @@ +/* + * The file intends to implement dynamic creation of EEH device, which will + * be bound with OF node and PCI device simutaneously. The EEH devices would + * be foundamental information for EEH core components to work proerly. Besides, + * We have to support multiple situations where dynamic creation of EEH device + * is required: + * + * 1) Before PCI emunation starts, we need create EEH devices according to the + * PCI sensitive OF nodes. + * 2) When PCI emunation is done, we need do the binding between PCI device and + * the associated EEH device. + * 3) DR (Dynamic Reconfiguration) would create PCI sensitive OF node. EEH device + * will be created while PCI sensitive OF node is detected from DR. + * 4) PCI hotplug needs redoing the binding between PCI device and EEH device. If + * PHB is newly inserted, we also need create EEH devices accordingly. + * + * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012. + * + * 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/export.h> +#include <linux/gfp.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/string.h> + +#include <asm/pci-bridge.h> +#include <asm/ppc-pci.h> + +/** + * eeh_dev_init - Create EEH device according to OF node + * @dn: device node + * @data: PHB + * + * It will create EEH device according to the given OF node. The function + * might be called by PCI emunation, DR, PHB hotplug. + */ +void *eeh_dev_init(struct device_node *dn, void *data) +{ + struct pci_controller *phb = data; + struct eeh_dev *edev; + + /* Allocate EEH device */ + edev = kzalloc(sizeof(*edev), GFP_KERNEL); + if (!edev) { + pr_warning("%s: out of memory\n", __func__); + return NULL; + } + + /* Associate EEH device with OF node */ + PCI_DN(dn)->edev = edev; + edev->dn = dn; + edev->phb = phb; + INIT_LIST_HEAD(&edev->list); + + return NULL; +} + +/** + * eeh_dev_phb_init_dynamic - Create EEH devices for devices included in PHB + * @phb: PHB + * + * Scan the PHB OF node and its child association, then create the + * EEH devices accordingly + */ +void eeh_dev_phb_init_dynamic(struct pci_controller *phb) +{ + struct device_node *dn = phb->dn; + + /* EEH PE for PHB */ + eeh_phb_pe_create(phb); + + /* EEH device for PHB */ + eeh_dev_init(dn, phb); + + /* EEH devices for children OF nodes */ + traverse_pci_devices(dn, eeh_dev_init, phb); +} + +/** + * eeh_dev_phb_init - Create EEH devices for devices included in existing PHBs + * + * Scan all the existing PHBs and create EEH devices for their OF + * nodes and their children OF nodes + */ +static int __init eeh_dev_phb_init(void) +{ + struct pci_controller *phb, *tmp; + + list_for_each_entry_safe(phb, tmp, &hose_list, list_node) + eeh_dev_phb_init_dynamic(phb); + + pr_info("EEH: devices created\n"); + + return 0; +} + +core_initcall(eeh_dev_phb_init); diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c new file mode 100644 index 000000000000..fb927af9a9ef --- /dev/null +++ b/arch/powerpc/kernel/eeh_driver.c @@ -0,0 +1,551 @@ +/* + * 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/module.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> + +/** + * eeh_pcid_name - Retrieve name of PCI device driver + * @pdev: PCI device + * + * This routine is used to retrieve the name of PCI device driver + * if that's valid. + */ +static inline const char *eeh_pcid_name(struct pci_dev *pdev) +{ + if (pdev && pdev->dev.driver) + return pdev->dev.driver->name; + return ""; +} + +/** + * eeh_pcid_get - Get the PCI device driver + * @pdev: PCI device + * + * The function is used to retrieve the PCI device driver for + * the indicated PCI device. Besides, we will increase the reference + * of the PCI device driver to prevent that being unloaded on + * the fly. Otherwise, kernel crash would be seen. + */ +static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev) +{ + if (!pdev || !pdev->driver) + return NULL; + + if (!try_module_get(pdev->driver->driver.owner)) + return NULL; + + return pdev->driver; +} + +/** + * eeh_pcid_put - Dereference on the PCI device driver + * @pdev: PCI device + * + * The function is called to do dereference on the PCI device + * driver of the indicated PCI device. + */ +static inline void eeh_pcid_put(struct pci_dev *pdev) +{ + if (!pdev || !pdev->driver) + return; + + module_put(pdev->driver->driver.owner); +} + +#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 + * @dev: PCI device + * + * This routine must be called when reporting temporary or permanent + * error to the particular PCI device to disable interrupt of that + * device. If the device has enabled MSI or MSI-X interrupt, we needn't + * do real work because EEH should freeze DMA transfers for those PCI + * devices encountering EEH errors, which includes MSI or MSI-X. + */ +static void eeh_disable_irq(struct pci_dev *dev) +{ + struct eeh_dev *edev = pci_dev_to_eeh_dev(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; + + edev->mode |= EEH_DEV_IRQ_DISABLED; + disable_irq_nosync(dev->irq); +} + +/** + * eeh_enable_irq - Enable interrupt for the recovering device + * @dev: PCI device + * + * This routine must be called to enable interrupt while failed + * device could be resumed. + */ +static void eeh_enable_irq(struct pci_dev *dev) +{ + struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); + + if ((edev->mode) & EEH_DEV_IRQ_DISABLED) { + edev->mode &= ~EEH_DEV_IRQ_DISABLED; + enable_irq(dev->irq); + } +} + +/** + * eeh_report_error - Report pci error to each device driver + * @data: eeh device + * @userdata: return value + * + * Report an EEH error to each device driver, collect up and + * merge the device driver responses. Cumulative response + * passed back in "userdata". + */ +static void *eeh_report_error(void *data, void *userdata) +{ + struct eeh_dev *edev = (struct eeh_dev *)data; + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + enum pci_ers_result rc, *res = userdata; + struct pci_driver *driver; + + /* We might not have the associated PCI device, + * then we should continue for next one. + */ + if (!dev) return NULL; + dev->error_state = pci_channel_io_frozen; + + driver = eeh_pcid_get(dev); + if (!driver) return NULL; + + eeh_disable_irq(dev); + + if (!driver->err_handler || + !driver->err_handler->error_detected) { + eeh_pcid_put(dev); + return NULL; + } + + 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; + + eeh_pcid_put(dev); + return NULL; +} + +/** + * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled + * @data: eeh device + * @userdata: return value + * + * 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 void *eeh_report_mmio_enabled(void *data, void *userdata) +{ + struct eeh_dev *edev = (struct eeh_dev *)data; + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + enum pci_ers_result rc, *res = userdata; + struct pci_driver *driver; + + driver = eeh_pcid_get(dev); + if (!driver) return NULL; + + if (!driver->err_handler || + !driver->err_handler->mmio_enabled) { + eeh_pcid_put(dev); + return NULL; + } + + 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; + + eeh_pcid_put(dev); + return NULL; +} + +/** + * eeh_report_reset - Tell device that slot has been reset + * @data: eeh device + * @userdata: return value + * + * This routine must be called while EEH tries to reset particular + * PCI device so that the associated PCI device driver could take + * some actions, usually to save data the driver needs so that the + * driver can work again while the device is recovered. + */ +static void *eeh_report_reset(void *data, void *userdata) +{ + struct eeh_dev *edev = (struct eeh_dev *)data; + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + enum pci_ers_result rc, *res = userdata; + struct pci_driver *driver; + + if (!dev) return NULL; + dev->error_state = pci_channel_io_normal; + + driver = eeh_pcid_get(dev); + if (!driver) return NULL; + + eeh_enable_irq(dev); + + if (!driver->err_handler || + !driver->err_handler->slot_reset) { + eeh_pcid_put(dev); + return NULL; + } + + 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; + + eeh_pcid_put(dev); + return NULL; +} + +/** + * eeh_report_resume - Tell device to resume normal operations + * @data: eeh device + * @userdata: return value + * + * This routine must be called to notify the device driver that it + * could resume so that the device driver can do some initialization + * to make the recovered device work again. + */ +static void *eeh_report_resume(void *data, void *userdata) +{ + struct eeh_dev *edev = (struct eeh_dev *)data; + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + struct pci_driver *driver; + + if (!dev) return NULL; + dev->error_state = pci_channel_io_normal; + + driver = eeh_pcid_get(dev); + if (!driver) return NULL; + + eeh_enable_irq(dev); + + if (!driver->err_handler || + !driver->err_handler->resume) { + eeh_pcid_put(dev); + return NULL; + } + + driver->err_handler->resume(dev); + + eeh_pcid_put(dev); + return NULL; +} + +/** + * eeh_report_failure - Tell device driver that device is dead. + * @data: eeh device + * @userdata: return value + * + * This informs the device driver that the device is permanently + * dead, and that no further recovery attempts will be made on it. + */ +static void *eeh_report_failure(void *data, void *userdata) +{ + struct eeh_dev *edev = (struct eeh_dev *)data; + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + struct pci_driver *driver; + + if (!dev) return NULL; + dev->error_state = pci_channel_io_perm_failure; + + driver = eeh_pcid_get(dev); + if (!driver) return NULL; + + eeh_disable_irq(dev); + + if (!driver->err_handler || + !driver->err_handler->error_detected) { + eeh_pcid_put(dev); + return NULL; + } + + driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); + + eeh_pcid_put(dev); + return NULL; +} + +/** + * eeh_reset_device - Perform actual reset of a pci slot + * @pe: EEH PE + * @bus: PCI bus corresponding to the isolcated slot + * + * This routine must be called to do reset on the indicated PE. + * During the reset, udev might be invoked because those affected + * PCI devices will be removed and then added. + */ +static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus) +{ + int cnt, rc; + + /* pcibios will clear the counter; save the value */ + cnt = pe->freeze_count; + + /* + * We don't remove the corresponding PE instances because + * we need the information afterwords. The attached EEH + * devices are expected to be attached soon when calling + * into pcibios_add_pci_devices(). + */ + if (bus) + __pcibios_remove_pci_devices(bus, 0); + + /* 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 = eeh_reset_pe(pe); + if (rc) + return rc; + + /* Restore PE */ + eeh_ops->configure_bridge(pe); + eeh_pe_restore_bars(pe); + + /* 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->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 + +/** + * eeh_handle_event - Reset a PCI device after hard lockup. + * @pe: EEH PE + * + * While PHB detects address or data parity errors on particular PCI + * slot, the associated PE will be frozen. Besides, DMA's occurring + * to wild addresses (which usually happen due to bugs in device + * drivers or in PCI adapter firmware) can cause EEH error. #SERR, + * #PERR or other misc PCI-related errors also can trigger EEH errors. + * + * 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). + */ +void eeh_handle_event(struct eeh_pe *pe) +{ + struct pci_bus *frozen_bus; + int rc = 0; + enum pci_ers_result result = PCI_ERS_RESULT_NONE; + + frozen_bus = eeh_pe_bus_get(pe); + if (!frozen_bus) { + pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n", + __func__, pe->phb->global_number, pe->addr); + return; + } + + pe->freeze_count++; + if (pe->freeze_count > EEH_MAX_ALLOWED_FREEZES) + goto excess_failures; + pr_warning("EEH: This PCI device has failed %d times in the last hour\n", + pe->freeze_count); + + /* 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. + */ + eeh_pe_dev_traverse(pe, 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_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000); + if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) { + 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(pe, EEH_LOG_TEMP); + + /* 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(pe, 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 = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + + if (rc < 0) + goto hard_fail; + if (rc) { + result = PCI_ERS_RESULT_NEED_RESET; + } else { + result = PCI_ERS_RESULT_NONE; + eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result); + } + } + + /* If all devices reported they can proceed, then re-enable DMA */ + if (result == PCI_ERS_RESULT_CAN_RECOVER) { + rc = eeh_pci_enable(pe, EEH_OPT_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(pe, NULL); + if (rc) { + printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc); + goto hard_fail; + } + result = PCI_ERS_RESULT_NONE; + eeh_pe_dev_traverse(pe, 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 */ + eeh_pe_dev_traverse(pe, eeh_report_resume, NULL); + + return; + +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. + */ + pr_err("EEH: PHB#%d-PE#%x has failed %d times in the\n" + "last hour and has been permanently disabled.\n" + "Please try reseating or replacing it.\n", + pe->phb->global_number, pe->addr, + pe->freeze_count); + goto perm_error; + +hard_fail: + pr_err("EEH: Unable to recover from failure from PHB#%d-PE#%x.\n" + "Please try reseating or replacing it\n", + pe->phb->global_number, pe->addr); + +perm_error: + eeh_slot_error_detail(pe, EEH_LOG_PERM); + + /* Notify all devices that they're about to go down. */ + eeh_pe_dev_traverse(pe, eeh_report_failure, NULL); + + /* Shut down the device drivers for good. */ + if (frozen_bus) + pcibios_remove_pci_devices(frozen_bus); +} diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c new file mode 100644 index 000000000000..185bedd926df --- /dev/null +++ b/arch/powerpc/kernel/eeh_event.c @@ -0,0 +1,142 @@ +/* + * 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 + * + * Copyright (c) 2005 Linas Vepstas <linas@linas.org> + */ + +#include <linux/delay.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/sched.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include <linux/kthread.h> +#include <asm/eeh_event.h> +#include <asm/ppc-pci.h> + +/** Overview: + * EEH error states may be detected within exception handlers; + * however, the recovery processing needs to occur asynchronously + * in a normal kernel context and not an interrupt context. + * This pair of routines creates an event and queues it onto a + * work-queue, where a worker thread can drive recovery. + */ + +/* EEH event workqueue setup. */ +static DEFINE_SPINLOCK(eeh_eventlist_lock); +LIST_HEAD(eeh_eventlist); +static void eeh_thread_launcher(struct work_struct *); +DECLARE_WORK(eeh_event_wq, eeh_thread_launcher); + +/* Serialize reset sequences for a given pci device */ +DEFINE_MUTEX(eeh_event_mutex); + +/** + * eeh_event_handler - Dispatch EEH events. + * @dummy - unused + * + * The detection of a frozen slot can occur inside an interrupt, + * where it can be hard to do anything about it. The goal of this + * routine is to pull these detection events out of the context + * of the interrupt handler, and re-dispatch them for processing + * at a later time in a normal context. + */ +static int eeh_event_handler(void * dummy) +{ + unsigned long flags; + struct eeh_event *event; + struct eeh_pe *pe; + + spin_lock_irqsave(&eeh_eventlist_lock, flags); + event = NULL; + + /* Unqueue the event, get ready to process. */ + if (!list_empty(&eeh_eventlist)) { + event = list_entry(eeh_eventlist.next, struct eeh_event, list); + list_del(&event->list); + } + spin_unlock_irqrestore(&eeh_eventlist_lock, flags); + + if (event == NULL) + return 0; + + /* Serialize processing of EEH events */ + mutex_lock(&eeh_event_mutex); + pe = event->pe; + eeh_pe_state_mark(pe, EEH_PE_RECOVERING); + pr_info("EEH: Detected PCI bus error on PHB#%d-PE#%x\n", + pe->phb->global_number, pe->addr); + + set_current_state(TASK_INTERRUPTIBLE); /* Don't add to load average */ + eeh_handle_event(pe); + eeh_pe_state_clear(pe, EEH_PE_RECOVERING); + + kfree(event); + mutex_unlock(&eeh_event_mutex); + + /* If there are no new errors after an hour, clear the counter. */ + if (pe && pe->freeze_count > 0) { + msleep_interruptible(3600*1000); + if (pe->freeze_count > 0) + pe->freeze_count--; + + } + + return 0; +} + +/** + * eeh_thread_launcher - Start kernel thread to handle EEH events + * @dummy - unused + * + * This routine is called to start the kernel thread for processing + * EEH event. + */ +static void eeh_thread_launcher(struct work_struct *dummy) +{ + if (IS_ERR(kthread_run(eeh_event_handler, NULL, "eehd"))) + printk(KERN_ERR "Failed to start EEH daemon\n"); +} + +/** + * eeh_send_failure_event - Generate a PCI error event + * @pe: EEH PE + * + * This routine can be called within an interrupt context; + * the actual event will be delivered in a normal context + * (from a workqueue). + */ +int eeh_send_failure_event(struct eeh_pe *pe) +{ + unsigned long flags; + struct eeh_event *event; + + event = kzalloc(sizeof(*event), GFP_ATOMIC); + if (!event) { + pr_err("EEH: out of memory, event not handled\n"); + return -ENOMEM; + } + event->pe = pe; + + /* We may or may not be called in an interrupt context */ + spin_lock_irqsave(&eeh_eventlist_lock, flags); + list_add(&event->list, &eeh_eventlist); + spin_unlock_irqrestore(&eeh_eventlist_lock, flags); + + schedule_work(&eeh_event_wq); + + return 0; +} diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c new file mode 100644 index 000000000000..9d4a9e8562b2 --- /dev/null +++ b/arch/powerpc/kernel/eeh_pe.c @@ -0,0 +1,653 @@ +/* + * The file intends to implement PE based on the information from + * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device. + * All the PEs should be organized as hierarchy tree. The first level + * of the tree will be associated to existing PHBs since the particular + * PE is only meaningful in one PHB domain. + * + * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012. + * + * 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/export.h> +#include <linux/gfp.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/string.h> + +#include <asm/pci-bridge.h> +#include <asm/ppc-pci.h> + +static LIST_HEAD(eeh_phb_pe); + +/** + * eeh_pe_alloc - Allocate PE + * @phb: PCI controller + * @type: PE type + * + * Allocate PE instance dynamically. + */ +static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type) +{ + struct eeh_pe *pe; + + /* Allocate PHB PE */ + pe = kzalloc(sizeof(struct eeh_pe), GFP_KERNEL); + if (!pe) return NULL; + + /* Initialize PHB PE */ + pe->type = type; + pe->phb = phb; + INIT_LIST_HEAD(&pe->child_list); + INIT_LIST_HEAD(&pe->child); + INIT_LIST_HEAD(&pe->edevs); + + return pe; +} + +/** + * eeh_phb_pe_create - Create PHB PE + * @phb: PCI controller + * + * The function should be called while the PHB is detected during + * system boot or PCI hotplug in order to create PHB PE. + */ +int eeh_phb_pe_create(struct pci_controller *phb) +{ + struct eeh_pe *pe; + + /* Allocate PHB PE */ + pe = eeh_pe_alloc(phb, EEH_PE_PHB); + if (!pe) { + pr_err("%s: out of memory!\n", __func__); + return -ENOMEM; + } + + /* Put it into the list */ + eeh_lock(); + list_add_tail(&pe->child, &eeh_phb_pe); + eeh_unlock(); + + pr_debug("EEH: Add PE for PHB#%d\n", phb->global_number); + + return 0; +} + +/** + * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB + * @phb: PCI controller + * + * The overall PEs form hierarchy tree. The first layer of the + * hierarchy tree is composed of PHB PEs. The function is used + * to retrieve the corresponding PHB PE according to the given PHB. + */ +static struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb) +{ + struct eeh_pe *pe; + + list_for_each_entry(pe, &eeh_phb_pe, child) { + /* + * Actually, we needn't check the type since + * the PE for PHB has been determined when that + * was created. + */ + if ((pe->type & EEH_PE_PHB) && pe->phb == phb) + return pe; + } + + return NULL; +} + +/** + * eeh_pe_next - Retrieve the next PE in the tree + * @pe: current PE + * @root: root PE + * + * The function is used to retrieve the next PE in the + * hierarchy PE tree. + */ +static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, + struct eeh_pe *root) +{ + struct list_head *next = pe->child_list.next; + + if (next == &pe->child_list) { + while (1) { + if (pe == root) + return NULL; + next = pe->child.next; + if (next != &pe->parent->child_list) + break; + pe = pe->parent; + } + } + + return list_entry(next, struct eeh_pe, child); +} + +/** + * eeh_pe_traverse - Traverse PEs in the specified PHB + * @root: root PE + * @fn: callback + * @flag: extra parameter to callback + * + * The function is used to traverse the specified PE and its + * child PEs. The traversing is to be terminated once the + * callback returns something other than NULL, or no more PEs + * to be traversed. + */ +static void *eeh_pe_traverse(struct eeh_pe *root, + eeh_traverse_func fn, void *flag) +{ + struct eeh_pe *pe; + void *ret; + + for (pe = root; pe; pe = eeh_pe_next(pe, root)) { + ret = fn(pe, flag); + if (ret) return ret; + } + + return NULL; +} + +/** + * eeh_pe_dev_traverse - Traverse the devices from the PE + * @root: EEH PE + * @fn: function callback + * @flag: extra parameter to callback + * + * The function is used to traverse the devices of the specified + * PE and its child PEs. + */ +void *eeh_pe_dev_traverse(struct eeh_pe *root, + eeh_traverse_func fn, void *flag) +{ + struct eeh_pe *pe; + struct eeh_dev *edev; + void *ret; + + if (!root) { + pr_warning("%s: Invalid PE %p\n", __func__, root); + return NULL; + } + + eeh_lock(); + + /* Traverse root PE */ + for (pe = root; pe; pe = eeh_pe_next(pe, root)) { + eeh_pe_for_each_dev(pe, edev) { + ret = fn(edev, flag); + if (ret) { + eeh_unlock(); + return ret; + } + } + } + + eeh_unlock(); + + return NULL; +} + +/** + * __eeh_pe_get - Check the PE address + * @data: EEH PE + * @flag: EEH device + * + * For one particular PE, it can be identified by PE address + * or tranditional BDF address. BDF address is composed of + * Bus/Device/Function number. The extra data referred by flag + * indicates which type of address should be used. + */ +static void *__eeh_pe_get(void *data, void *flag) +{ + struct eeh_pe *pe = (struct eeh_pe *)data; + struct eeh_dev *edev = (struct eeh_dev *)flag; + + /* Unexpected PHB PE */ + if (pe->type & EEH_PE_PHB) + return NULL; + + /* We prefer PE address */ + if (edev->pe_config_addr && + (edev->pe_config_addr == pe->addr)) + return pe; + + /* Try BDF address */ + if (edev->pe_config_addr && + (edev->config_addr == pe->config_addr)) + return pe; + + return NULL; +} + +/** + * eeh_pe_get - Search PE based on the given address + * @edev: EEH device + * + * Search the corresponding PE based on the specified address which + * is included in the eeh device. The function is used to check if + * the associated PE has been created against the PE address. It's + * notable that the PE address has 2 format: traditional PE address + * which is composed of PCI bus/device/function number, or unified + * PE address. + */ +static struct eeh_pe *eeh_pe_get(struct eeh_dev *edev) +{ + struct eeh_pe *root = eeh_phb_pe_get(edev->phb); + struct eeh_pe *pe; + + pe = eeh_pe_traverse(root, __eeh_pe_get, edev); + + return pe; +} + +/** + * eeh_pe_get_parent - Retrieve the parent PE + * @edev: EEH device + * + * The whole PEs existing in the system are organized as hierarchy + * tree. The function is used to retrieve the parent PE according + * to the parent EEH device. + */ +static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev) +{ + struct device_node *dn; + struct eeh_dev *parent; + + /* + * It might have the case for the indirect parent + * EEH device already having associated PE, but + * the direct parent EEH device doesn't have yet. + */ + dn = edev->dn->parent; + while (dn) { + /* We're poking out of PCI territory */ + if (!PCI_DN(dn)) return NULL; + + parent = of_node_to_eeh_dev(dn); + /* We're poking out of PCI territory */ + if (!parent) return NULL; + + if (parent->pe) + return parent->pe; + + dn = dn->parent; + } + + return NULL; +} + +/** + * eeh_add_to_parent_pe - Add EEH device to parent PE + * @edev: EEH device + * + * Add EEH device to the parent PE. If the parent PE already + * exists, the PE type will be changed to EEH_PE_BUS. Otherwise, + * we have to create new PE to hold the EEH device and the new + * PE will be linked to its parent PE as well. + */ +int eeh_add_to_parent_pe(struct eeh_dev *edev) +{ + struct eeh_pe *pe, *parent; + + eeh_lock(); + + /* + * Search the PE has been existing or not according + * to the PE address. If that has been existing, the + * PE should be composed of PCI bus and its subordinate + * components. + */ + pe = eeh_pe_get(edev); + if (pe && !(pe->type & EEH_PE_INVALID)) { + if (!edev->pe_config_addr) { + eeh_unlock(); + pr_err("%s: PE with addr 0x%x already exists\n", + __func__, edev->config_addr); + return -EEXIST; + } + + /* Mark the PE as type of PCI bus */ + pe->type = EEH_PE_BUS; + edev->pe = pe; + + /* Put the edev to PE */ + list_add_tail(&edev->list, &pe->edevs); + eeh_unlock(); + pr_debug("EEH: Add %s to Bus PE#%x\n", + edev->dn->full_name, pe->addr); + + return 0; + } else if (pe && (pe->type & EEH_PE_INVALID)) { + list_add_tail(&edev->list, &pe->edevs); + edev->pe = pe; + /* + * We're running to here because of PCI hotplug caused by + * EEH recovery. We need clear EEH_PE_INVALID until the top. + */ + parent = pe; + while (parent) { + if (!(parent->type & EEH_PE_INVALID)) + break; + parent->type &= ~EEH_PE_INVALID; + parent = parent->parent; + } + eeh_unlock(); + pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n", + edev->dn->full_name, pe->addr, pe->parent->addr); + + return 0; + } + + /* Create a new EEH PE */ + pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE); + if (!pe) { + eeh_unlock(); + pr_err("%s: out of memory!\n", __func__); + return -ENOMEM; + } + pe->addr = edev->pe_config_addr; + pe->config_addr = edev->config_addr; + + /* + * Put the new EEH PE into hierarchy tree. If the parent + * can't be found, the newly created PE will be attached + * to PHB directly. Otherwise, we have to associate the + * PE with its parent. + */ + parent = eeh_pe_get_parent(edev); + if (!parent) { + parent = eeh_phb_pe_get(edev->phb); + if (!parent) { + eeh_unlock(); + pr_err("%s: No PHB PE is found (PHB Domain=%d)\n", + __func__, edev->phb->global_number); + edev->pe = NULL; + kfree(pe); + return -EEXIST; + } + } + pe->parent = parent; + + /* + * Put the newly created PE into the child list and + * link the EEH device accordingly. + */ + list_add_tail(&pe->child, &parent->child_list); + list_add_tail(&edev->list, &pe->edevs); + edev->pe = pe; + eeh_unlock(); + pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n", + edev->dn->full_name, pe->addr, pe->parent->addr); + + return 0; +} + +/** + * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE + * @edev: EEH device + * @purge_pe: remove PE or not + * + * The PE hierarchy tree might be changed when doing PCI hotplug. + * Also, the PCI devices or buses could be removed from the system + * during EEH recovery. So we have to call the function remove the + * corresponding PE accordingly if necessary. + */ +int eeh_rmv_from_parent_pe(struct eeh_dev *edev, int purge_pe) +{ + struct eeh_pe *pe, *parent, *child; + int cnt; + + if (!edev->pe) { + pr_warning("%s: No PE found for EEH device %s\n", + __func__, edev->dn->full_name); + return -EEXIST; + } + + eeh_lock(); + + /* Remove the EEH device */ + pe = edev->pe; + edev->pe = NULL; + list_del(&edev->list); + + /* + * Check if the parent PE includes any EEH devices. + * If not, we should delete that. Also, we should + * delete the parent PE if it doesn't have associated + * child PEs and EEH devices. + */ + while (1) { + parent = pe->parent; + if (pe->type & EEH_PE_PHB) + break; + + if (purge_pe) { + if (list_empty(&pe->edevs) && + list_empty(&pe->child_list)) { + list_del(&pe->child); + kfree(pe); + } else { + break; + } + } else { + if (list_empty(&pe->edevs)) { + cnt = 0; + list_for_each_entry(child, &pe->child_list, child) { + if (!(child->type & EEH_PE_INVALID)) { + cnt++; + break; + } + } + + if (!cnt) + pe->type |= EEH_PE_INVALID; + else + break; + } + } + + pe = parent; + } + + eeh_unlock(); + + return 0; +} + +/** + * __eeh_pe_state_mark - Mark the state for the PE + * @data: EEH PE + * @flag: state + * + * The function is used to mark the indicated state for the given + * PE. Also, the associated PCI devices will be put into IO frozen + * state as well. + */ +static void *__eeh_pe_state_mark(void *data, void *flag) +{ + struct eeh_pe *pe = (struct eeh_pe *)data; + int state = *((int *)flag); + struct eeh_dev *tmp; + struct pci_dev *pdev; + + /* + * Mark the PE with the indicated state. Also, + * the associated PCI device will be put into + * I/O frozen state to avoid I/O accesses from + * the PCI device driver. + */ + pe->state |= state; + eeh_pe_for_each_dev(pe, tmp) { + pdev = eeh_dev_to_pci_dev(tmp); + if (pdev) + pdev->error_state = pci_channel_io_frozen; + } + + return NULL; +} + +/** + * eeh_pe_state_mark - Mark specified state for PE and its associated device + * @pe: EEH PE + * + * EEH error affects the current PE and its child PEs. The function + * is used to mark appropriate state for the affected PEs and the + * associated devices. + */ +void eeh_pe_state_mark(struct eeh_pe *pe, int state) +{ + eeh_lock(); + eeh_pe_traverse(pe, __eeh_pe_state_mark, &state); + eeh_unlock(); +} + +/** + * __eeh_pe_state_clear - Clear state for the PE + * @data: EEH PE + * @flag: state + * + * The function is used to clear the indicated state from the + * given PE. Besides, we also clear the check count of the PE + * as well. + */ +static void *__eeh_pe_state_clear(void *data, void *flag) +{ + struct eeh_pe *pe = (struct eeh_pe *)data; + int state = *((int *)flag); + + pe->state &= ~state; + pe->check_count = 0; + + return NULL; +} + +/** + * eeh_pe_state_clear - Clear state for the PE and its children + * @pe: PE + * @state: state to be cleared + * + * When the PE and its children has been recovered from error, + * we need clear the error state for that. The function is used + * for the purpose. + */ +void eeh_pe_state_clear(struct eeh_pe *pe, int state) +{ + eeh_lock(); + eeh_pe_traverse(pe, __eeh_pe_state_clear, &state); + eeh_unlock(); +} + +/** + * eeh_restore_one_device_bars - Restore the Base Address Registers for one device + * @data: EEH device + * @flag: Unused + * + * 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 void *eeh_restore_one_device_bars(void *data, void *flag) +{ + int i; + u32 cmd; + struct eeh_dev *edev = (struct eeh_dev *)data; + struct device_node *dn = eeh_dev_to_of_node(edev); + + for (i = 4; i < 10; i++) + eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]); + /* 12 == Expansion ROM Address */ + eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]); + +#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) +#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)]) + + eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1, + SAVED_BYTE(PCI_CACHE_LINE_SIZE)); + eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1, + SAVED_BYTE(PCI_LATENCY_TIMER)); + + /* max latency, min grant, interrupt pin and line */ + eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]); + + /* + * Restore PERR & SERR bits, some devices require it, + * don't touch the other command bits + */ + eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd); + if (edev->config_space[1] & PCI_COMMAND_PARITY) + cmd |= PCI_COMMAND_PARITY; + else + cmd &= ~PCI_COMMAND_PARITY; + if (edev->config_space[1] & PCI_COMMAND_SERR) + cmd |= PCI_COMMAND_SERR; + else + cmd &= ~PCI_COMMAND_SERR; + eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd); + + return NULL; +} + +/** + * eeh_pe_restore_bars - Restore the PCI config space info + * @pe: EEH PE + * + * This routine performs a recursive walk to the children + * of this device as well. + */ +void eeh_pe_restore_bars(struct eeh_pe *pe) +{ + /* + * We needn't take the EEH lock since eeh_pe_dev_traverse() + * will take that. + */ + eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL); +} + +/** + * eeh_pe_bus_get - Retrieve PCI bus according to the given PE + * @pe: EEH PE + * + * Retrieve the PCI bus according to the given PE. Basically, + * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the + * primary PCI bus will be retrieved. The parent bus will be + * returned for BUS PE. However, we don't have associated PCI + * bus for DEVICE PE. + */ +struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) +{ + struct pci_bus *bus = NULL; + struct eeh_dev *edev; + struct pci_dev *pdev; + + eeh_lock(); + + if (pe->type & EEH_PE_PHB) { + bus = pe->phb->bus; + } else if (pe->type & EEH_PE_BUS || + pe->type & EEH_PE_DEVICE) { + edev = list_first_entry(&pe->edevs, struct eeh_dev, list); + pdev = eeh_dev_to_pci_dev(edev); + if (pdev) + bus = pdev->bus; + } + + eeh_unlock(); + + return bus; +} diff --git a/arch/powerpc/kernel/eeh_sysfs.c b/arch/powerpc/kernel/eeh_sysfs.c new file mode 100644 index 000000000000..e7ae3484918c --- /dev/null +++ b/arch/powerpc/kernel/eeh_sysfs.c @@ -0,0 +1,74 @@ +/* + * Sysfs entries for PCI Error Recovery for PAPR-compliant platform. + * Copyright IBM Corporation 2007 + * Copyright Linas Vepstas <linas@austin.ibm.com> 2007 + * + * 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/pci.h> +#include <linux/stat.h> +#include <asm/ppc-pci.h> +#include <asm/pci-bridge.h> + +/** + * EEH_SHOW_ATTR -- Create sysfs entry for eeh statistic + * @_name: name of file in sysfs directory + * @_memb: name of member in struct pci_dn to access + * @_format: printf format for display + * + * All of the attributes look very similar, so just + * auto-gen a cut-n-paste routine to display them. + */ +#define EEH_SHOW_ATTR(_name,_memb,_format) \ +static ssize_t eeh_show_##_name(struct device *dev, \ + struct device_attribute *attr, char *buf) \ +{ \ + struct pci_dev *pdev = to_pci_dev(dev); \ + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev); \ + \ + if (!edev) \ + return 0; \ + \ + return sprintf(buf, _format "\n", edev->_memb); \ +} \ +static DEVICE_ATTR(_name, S_IRUGO, eeh_show_##_name, NULL); + +EEH_SHOW_ATTR(eeh_mode, mode, "0x%x"); +EEH_SHOW_ATTR(eeh_config_addr, config_addr, "0x%x"); +EEH_SHOW_ATTR(eeh_pe_config_addr, pe_config_addr, "0x%x"); + +void eeh_sysfs_add_device(struct pci_dev *pdev) +{ + int rc=0; + + rc += device_create_file(&pdev->dev, &dev_attr_eeh_mode); + rc += device_create_file(&pdev->dev, &dev_attr_eeh_config_addr); + rc += device_create_file(&pdev->dev, &dev_attr_eeh_pe_config_addr); + + if (rc) + printk(KERN_WARNING "EEH: Unable to create sysfs entries\n"); +} + +void eeh_sysfs_remove_device(struct pci_dev *pdev) +{ + device_remove_file(&pdev->dev, &dev_attr_eeh_mode); + device_remove_file(&pdev->dev, &dev_attr_eeh_config_addr); + device_remove_file(&pdev->dev, &dev_attr_eeh_pe_config_addr); +} diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c new file mode 100644 index 000000000000..3f608800c06b --- /dev/null +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -0,0 +1,111 @@ +/* + * Derived from "arch/powerpc/platforms/pseries/pci_dlpar.c" + * + * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com> + * Copyright (C) 2005 International Business Machines + * + * Updates, 2005, John Rose <johnrose@austin.ibm.com> + * Updates, 2005, Linas Vepstas <linas@austin.ibm.com> + * Updates, 2013, Gavin Shan <shangw@linux.vnet.ibm.com> + * + * 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. + */ + +#include <linux/pci.h> +#include <linux/export.h> +#include <asm/pci-bridge.h> +#include <asm/ppc-pci.h> +#include <asm/firmware.h> +#include <asm/eeh.h> + +/** + * __pcibios_remove_pci_devices - remove all devices under this bus + * @bus: the indicated PCI bus + * @purge_pe: destroy the PE on removal of PCI devices + * + * Remove all of the PCI devices under this bus both from the + * linux pci device tree, and from the powerpc EEH address cache. + * By default, the corresponding PE will be destroied during the + * normal PCI hotplug path. For PCI hotplug during EEH recovery, + * the corresponding PE won't be destroied and deallocated. + */ +void __pcibios_remove_pci_devices(struct pci_bus *bus, int purge_pe) +{ + struct pci_dev *dev, *tmp; + struct pci_bus *child_bus; + + /* First go down child busses */ + list_for_each_entry(child_bus, &bus->children, node) + __pcibios_remove_pci_devices(child_bus, purge_pe); + + pr_debug("PCI: Removing devices on bus %04x:%02x\n", + pci_domain_nr(bus), bus->number); + list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) { + pr_debug(" * Removing %s...\n", pci_name(dev)); + eeh_remove_bus_device(dev, purge_pe); + pci_stop_and_remove_bus_device(dev); + } +} + +/** + * pcibios_remove_pci_devices - remove all devices under this bus + * @bus: the indicated PCI bus + * + * Remove all of the PCI devices under this bus both from the + * linux pci device tree, and from the powerpc EEH address cache. + */ +void pcibios_remove_pci_devices(struct pci_bus *bus) +{ + __pcibios_remove_pci_devices(bus, 1); +} +EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices); + +/** + * pcibios_add_pci_devices - adds new pci devices to bus + * @bus: the indicated PCI bus + * + * This routine will find and fixup new pci devices under + * the indicated bus. This routine presumes that there + * might already be some devices under this bridge, so + * it carefully tries to add only new devices. (And that + * is how this routine differs from other, similar pcibios + * routines.) + */ +void pcibios_add_pci_devices(struct pci_bus * bus) +{ + int slotno, num, mode, pass, max; + struct pci_dev *dev; + struct device_node *dn = pci_bus_to_OF_node(bus); + + eeh_add_device_tree_early(dn); + + mode = PCI_PROBE_NORMAL; + if (ppc_md.pci_probe_mode) + mode = ppc_md.pci_probe_mode(bus); + + if (mode == PCI_PROBE_DEVTREE) { + /* use ofdt-based probe */ + of_rescan_bus(dn, bus); + } else if (mode == PCI_PROBE_NORMAL) { + /* use legacy probe */ + slotno = PCI_SLOT(PCI_DN(dn->child)->devfn); + num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0)); + if (!num) + return; + pcibios_setup_bus_devices(bus); + max = bus->busn_res.start; + for (pass = 0; pass < 2; pass++) { + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || + dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) + max = pci_scan_bridge(bus, dev, + max, pass); + } + } + } + pcibios_finish_adding_to_bus(bus); +} +EXPORT_SYMBOL_GPL(pcibios_add_pci_devices); |