summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/eeh.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/eeh.c')
-rw-r--r--arch/powerpc/kernel/eeh.c1070
1 files changed, 1070 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
new file mode 100644
index 0000000..39954fe
--- /dev/null
+++ b/arch/powerpc/kernel/eeh.c
@@ -0,0 +1,1070 @@
+/*
+ * 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;
+
+/* Lock to avoid races due to multiple reports of an error */
+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;
+ bool valid_cfg_log = true;
+
+ /*
+ * When the PHB is fenced or dead, it's pointless to collect
+ * the data from PCI config space because it should return
+ * 0xFF's. For ER, we still retrieve the data from the PCI
+ * config space.
+ */
+ if (eeh_probe_mode_dev() &&
+ (pe->type & EEH_PE_PHB) &&
+ (pe->state & (EEH_PE_ISOLATED | EEH_PE_PHB_DEAD)))
+ valid_cfg_log = false;
+
+ if (valid_cfg_log) {
+ 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 + loglen,
+ EEH_PCI_REGS_LOG_LEN - loglen);
+ }
+ }
+
+ 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;
+ int hugepage_shift;
+
+ /*
+ * We won't find hugepages here, iomem
+ */
+ ptep = find_linux_pte_or_hugepte(init_mm.pgd, token, &hugepage_shift);
+ if (!ptep)
+ return token;
+ WARN_ON(hugepage_shift);
+ pa = pte_pfn(*ptep) << PAGE_SHIFT;
+
+ return pa | (token & (PAGE_SIZE-1));
+}
+
+/*
+ * On PowerNV platform, we might already have fenced PHB there.
+ * For that case, it's meaningless to recover frozen PE. Intead,
+ * We have to handle fenced PHB firstly.
+ */
+static int eeh_phb_check_failure(struct eeh_pe *pe)
+{
+ struct eeh_pe *phb_pe;
+ unsigned long flags;
+ int ret;
+
+ if (!eeh_probe_mode_dev())
+ return -EPERM;
+
+ /* Find the PHB PE */
+ phb_pe = eeh_phb_pe_get(pe->phb);
+ if (!phb_pe) {
+ pr_warning("%s Can't find PE for PHB#%d\n",
+ __func__, pe->phb->global_number);
+ return -EEXIST;
+ }
+
+ /* If the PHB has been in problematic state */
+ eeh_serialize_lock(&flags);
+ if (phb_pe->state & (EEH_PE_ISOLATED | EEH_PE_PHB_DEAD)) {
+ ret = 0;
+ goto out;
+ }
+
+ /* Check PHB state */
+ ret = eeh_ops->get_state(phb_pe, NULL);
+ 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)) {
+ ret = 0;
+ goto out;
+ }
+
+ /* Isolate the PHB and send event */
+ eeh_pe_state_mark(phb_pe, EEH_PE_ISOLATED);
+ eeh_serialize_unlock(flags);
+ eeh_send_failure_event(phb_pe);
+
+ pr_err("EEH: PHB#%x failure detected\n",
+ phb_pe->phb->global_number);
+ dump_stack();
+
+ return 1;
+out:
+ eeh_serialize_unlock(flags);
+ return ret;
+}
+
+/**
+ * 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;
+ }
+
+ /*
+ * On PowerNV platform, we might already have fenced PHB
+ * there and we need take care of that firstly.
+ */
+ ret = eeh_phb_check_failure(pe);
+ if (ret > 0)
+ return ret;
+
+ /* 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.
+ */
+ eeh_serialize_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);
+ eeh_serialize_unlock(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.
+ */
+ pr_err("EEH: Frozen PE#%x detected on PHB#%x\n",
+ pe->addr, pe->phb->global_number);
+ dump_stack();
+
+ return 1;
+
+dn_unlock:
+ eeh_serialize_unlock(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 flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
+ 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 & flags) == flags)
+ 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.
+ */
+int eeh_init(void)
+{
+ struct pci_controller *hose, *tmp;
+ struct device_node *phb;
+ static int cnt = 0;
+ int ret = 0;
+
+ /*
+ * We have to delay the initialization on PowerNV after
+ * the PCI hierarchy tree has been built because the PEs
+ * are figured out based on PCI devices instead of device
+ * tree nodes
+ */
+ if (machine_is(powernv) && cnt++ <= 0)
+ return 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;
+ }
+
+ /* Initialize EEH event */
+ ret = eeh_event_init();
+ if (ret)
+ return ret;
+
+ /* 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);
+ }
+ } else if (eeh_probe_mode_dev()) {
+ list_for_each_entry_safe(hose, tmp,
+ &hose_list, list_node)
+ pci_walk_bus(hose->bus, eeh_ops->dev_probe, NULL);
+ } else {
+ pr_warning("%s: Invalid probe mode %d\n",
+ __func__, eeh_probe_mode);
+ return -EINVAL;
+ }
+
+ /*
+ * Call platform post-initialization. Actually, It's good chance
+ * to inform platform that EEH is ready to supply service if the
+ * I/O cache stuff has been built up.
+ */
+ if (eeh_ops->post_init) {
+ ret = eeh_ops->post_init();
+ if (ret)
+ return ret;
+ }
+
+ 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 we're doing EEH probe based on PCI device, we
+ * would delay the probe until late stage because
+ * the PCI device isn't available this moment.
+ */
+ if (!eeh_probe_mode_devtree())
+ return;
+
+ 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;
+
+ 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;
+
+ /*
+ * We have to do the EEH probe here because the PCI device
+ * hasn't been created yet in the early stage.
+ */
+ if (eeh_probe_mode_dev())
+ eeh_ops->dev_probe(dev, NULL);
+
+ 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);
OpenPOWER on IntegriCloud