--- /dev/null
+/*
+ * eeh.c
+ * Copyright (C) 2001 Dave Engebretsen & Todd Inglett IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/rbtree.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+#include <asm/eeh.h>
+#include <asm/eeh_event.h>
+#include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/ppc-pci.h>
+#include <asm/rtas.h>
+
+#undef DEBUG
+
+/** Overview:
+ * EEH, or "Extended Error Handling" is a PCI bridge technology for
+ * dealing with PCI bus errors that can't be dealt with within the
+ * usual PCI framework, except by check-stopping the CPU. Systems
+ * that are designed for high-availability/reliability cannot afford
+ * to crash due to a "mere" PCI error, thus the need for EEH.
+ * An EEH-capable bridge operates by converting a detected error
+ * into a "slot freeze", taking the PCI adapter off-line, making
+ * the slot behave, from the OS'es point of view, as if the slot
+ * were "empty": all reads return 0xff's and all writes are silently
+ * ignored. EEH slot isolation events can be triggered by parity
+ * errors on the address or data busses (e.g. during posted writes),
+ * which in turn might be caused by low voltage on the bus, dust,
+ * vibration, humidity, radioactivity or plain-old failed hardware.
+ *
+ * Note, however, that one of the leading causes of EEH slot
+ * freeze events are buggy device drivers, buggy device microcode,
+ * or buggy device hardware. This is because any attempt by the
+ * device to bus-master data to a memory address that is not
+ * assigned to the device will trigger a slot freeze. (The idea
+ * is to prevent devices-gone-wild from corrupting system memory).
+ * Buggy hardware/drivers will have a miserable time co-existing
+ * with EEH.
+ *
+ * Ideally, a PCI device driver, when suspecting that an isolation
+ * event has occured (e.g. by reading 0xff's), will then ask EEH
+ * whether this is the case, and then take appropriate steps to
+ * reset the PCI slot, the PCI device, and then resume operations.
+ * However, until that day, the checking is done here, with the
+ * eeh_check_failure() routine embedded in the MMIO macros. If
+ * the slot is found to be isolated, an "EEH Event" is synthesized
+ * and sent out for processing.
+ */
+
+/* If a device driver keeps reading an MMIO register in an interrupt
+ * handler after a slot isolation event has occurred, we assume it
+ * is broken and panic. This sets the threshold for how many read
+ * attempts we allow before panicking.
+ */
+#define EEH_MAX_FAILS 100000
+
+/* RTAS tokens */
+static int ibm_set_eeh_option;
+static int ibm_set_slot_reset;
+static int ibm_read_slot_reset_state;
+static int ibm_read_slot_reset_state2;
+static int ibm_slot_error_detail;
+static int ibm_get_config_addr_info;
+static int ibm_configure_bridge;
+
+int eeh_subsystem_enabled;
+EXPORT_SYMBOL(eeh_subsystem_enabled);
+
+/* Lock to avoid races due to multiple reports of an error */
+static DEFINE_SPINLOCK(confirm_error_lock);
+
+/* Buffer for reporting slot-error-detail rtas calls */
+static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
+static DEFINE_SPINLOCK(slot_errbuf_lock);
+static int eeh_error_buf_size;
+
+/* System monitoring statistics */
+static unsigned long no_device;
+static unsigned long no_dn;
+static unsigned long no_cfg_addr;
+static unsigned long ignored_check;
+static unsigned long total_mmio_ffs;
+static unsigned long false_positives;
+static unsigned long ignored_failures;
+static unsigned long slot_resets;
+
+#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
+
+/* --------------------------------------------------------------- */
+/* Below lies the EEH event infrastructure */
+
+void eeh_slot_error_detail (struct pci_dn *pdn, int severity)
+{
+ int config_addr;
+ unsigned long flags;
+ int rc;
+
+ /* Log the error with the rtas logger */
+ spin_lock_irqsave(&slot_errbuf_lock, flags);
+ memset(slot_errbuf, 0, eeh_error_buf_size);
+
+ /* Use PE configuration address, if present */
+ config_addr = pdn->eeh_config_addr;
+ if (pdn->eeh_pe_config_addr)
+ config_addr = pdn->eeh_pe_config_addr;
+
+ rc = rtas_call(ibm_slot_error_detail,
+ 8, 1, NULL, config_addr,
+ BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid), NULL, 0,
+ virt_to_phys(slot_errbuf),
+ eeh_error_buf_size,
+ severity);
+
+ if (rc == 0)
+ log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
+ spin_unlock_irqrestore(&slot_errbuf_lock, flags);
+}
+
+/**
+ * read_slot_reset_state - Read the reset state of a device node's slot
+ * @dn: device node to read
+ * @rets: array to return results in
+ */
+static int read_slot_reset_state(struct pci_dn *pdn, int rets[])
+{
+ int token, outputs;
+ int config_addr;
+
+ if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
+ token = ibm_read_slot_reset_state2;
+ outputs = 4;
+ } else {
+ token = ibm_read_slot_reset_state;
+ rets[2] = 0; /* fake PE Unavailable info */
+ outputs = 3;
+ }
+
+ /* Use PE configuration address, if present */
+ config_addr = pdn->eeh_config_addr;
+ if (pdn->eeh_pe_config_addr)
+ config_addr = pdn->eeh_pe_config_addr;
+
+ return rtas_call(token, 3, outputs, rets, config_addr,
+ BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid));
+}
+
+/**
+ * eeh_token_to_phys - convert EEH address token to phys address
+ * @token i/o token, should be address in the form 0xA....
+ */
+static inline unsigned long eeh_token_to_phys(unsigned long token)
+{
+ pte_t *ptep;
+ unsigned long pa;
+
+ ptep = find_linux_pte(init_mm.pgd, token);
+ if (!ptep)
+ return token;
+ pa = pte_pfn(*ptep) << PAGE_SHIFT;
+
+ return pa | (token & (PAGE_SIZE-1));
+}
+
+/**
+ * Return the "partitionable endpoint" (pe) under which this device lies
+ */
+struct device_node * find_device_pe(struct device_node *dn)
+{
+ while ((dn->parent) && PCI_DN(dn->parent) &&
+ (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) {
+ dn = dn->parent;
+ }
+ return dn;
+}
+
+/** Mark all devices that are peers of this device as failed.
+ * Mark the device driver too, so that it can see the failure
+ * immediately; this is critical, since some drivers poll
+ * status registers in interrupts ... If a driver is polling,
+ * and the slot is frozen, then the driver can deadlock in
+ * an interrupt context, which is bad.
+ */
+
+static void __eeh_mark_slot (struct device_node *dn, int mode_flag)
+{
+ while (dn) {
+ if (PCI_DN(dn)) {
+ /* Mark the pci device driver too */
+ struct pci_dev *dev = PCI_DN(dn)->pcidev;
+
+ PCI_DN(dn)->eeh_mode |= mode_flag;
+
+ if (dev && dev->driver)
+ dev->error_state = pci_channel_io_frozen;
+
+ if (dn->child)
+ __eeh_mark_slot (dn->child, mode_flag);
+ }
+ dn = dn->sibling;
+ }
+}
+
+void eeh_mark_slot (struct device_node *dn, int mode_flag)
+{
+ dn = find_device_pe (dn);
+
+ /* Back up one, since config addrs might be shared */
+ if (PCI_DN(dn) && PCI_DN(dn)->eeh_pe_config_addr)
+ dn = dn->parent;
+
+ PCI_DN(dn)->eeh_mode |= mode_flag;
+ __eeh_mark_slot (dn->child, mode_flag);
+}
+
+static void __eeh_clear_slot (struct device_node *dn, int mode_flag)
+{
+ while (dn) {
+ if (PCI_DN(dn)) {
+ PCI_DN(dn)->eeh_mode &= ~mode_flag;
+ PCI_DN(dn)->eeh_check_count = 0;
+ if (dn->child)
+ __eeh_clear_slot (dn->child, mode_flag);
+ }
+ dn = dn->sibling;
+ }
+}
+
+void eeh_clear_slot (struct device_node *dn, int mode_flag)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&confirm_error_lock, flags);
+
+ dn = find_device_pe (dn);
+
+ /* Back up one, since config addrs might be shared */
+ if (PCI_DN(dn) && PCI_DN(dn)->eeh_pe_config_addr)
+ dn = dn->parent;
+
+ PCI_DN(dn)->eeh_mode &= ~mode_flag;
+ PCI_DN(dn)->eeh_check_count = 0;
+ __eeh_clear_slot (dn->child, mode_flag);
+ spin_unlock_irqrestore(&confirm_error_lock, flags);
+}
+
+/**
+ * eeh_dn_check_failure - check if all 1's data is due to EEH slot freeze
+ * @dn device node
+ * @dev pci device, if known
+ *
+ * Check for an EEH failure for the given device node. Call this
+ * routine if the result of a read was all 0xff's and you want to
+ * find out if this is due to an EEH slot freeze. This routine
+ * will query firmware for the EEH status.
+ *
+ * Returns 0 if there has not been an EEH error; otherwise returns
+ * a non-zero value and queues up a slot isolation event notification.
+ *
+ * It is safe to call this routine in an interrupt context.
+ */
+int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
+{
+ int ret;
+ int rets[3];
+ unsigned long flags;
+ struct pci_dn *pdn;
+ enum pci_channel_state state;
+ int rc = 0;
+
+ total_mmio_ffs++;
+
+ if (!eeh_subsystem_enabled)
+ return 0;
+
+ if (!dn) {
+ no_dn++;
+ return 0;
+ }
+ pdn = PCI_DN(dn);
+
+ /* Access to IO BARs might get this far and still not want checking. */
+ if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) ||
+ pdn->eeh_mode & EEH_MODE_NOCHECK) {
+ ignored_check++;
+#ifdef DEBUG
+ printk ("EEH:ignored check (%x) for %s %s\n",
+ pdn->eeh_mode, pci_name (dev), dn->full_name);
+#endif
+ return 0;
+ }
+
+ if (!pdn->eeh_config_addr && !pdn->eeh_pe_config_addr) {
+ no_cfg_addr++;
+ return 0;
+ }
+
+ /* If we already have a pending isolation event for this
+ * slot, we know it's bad already, we don't need to check.
+ * Do this checking under a lock; as multiple PCI devices
+ * in one slot might report errors simultaneously, and we
+ * only want one error recovery routine running.
+ */
+ spin_lock_irqsave(&confirm_error_lock, flags);
+ rc = 1;
+ if (pdn->eeh_mode & EEH_MODE_ISOLATED) {
+ pdn->eeh_check_count ++;
+ if (pdn->eeh_check_count >= EEH_MAX_FAILS) {
+ printk (KERN_ERR "EEH: Device driver ignored %d bad reads, panicing\n",
+ pdn->eeh_check_count);
+ dump_stack();
+
+ /* re-read the slot reset state */
+ if (read_slot_reset_state(pdn, rets) != 0)
+ rets[0] = -1; /* reset state unknown */
+
+ /* If we are here, then we hit an infinite loop. Stop. */
+ panic("EEH: MMIO halt (%d) on device:%s\n", rets[0], pci_name(dev));
+ }
+ goto dn_unlock;
+ }
+
+ /*
+ * Now test for an EEH failure. This is VERY expensive.
+ * Note that the eeh_config_addr may be a parent device
+ * in the case of a device behind a bridge, or it may be
+ * function zero of a multi-function device.
+ * In any case they must share a common PHB.
+ */
+ ret = read_slot_reset_state(pdn, rets);
+
+ /* If the call to firmware failed, punt */
+ if (ret != 0) {
+ printk(KERN_WARNING "EEH: read_slot_reset_state() failed; rc=%d dn=%s\n",
+ ret, dn->full_name);
+ false_positives++;
+ rc = 0;
+ goto dn_unlock;
+ }
+
+ /* If EEH is not supported on this device, punt. */
+ if (rets[1] != 1) {
+ printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n",
+ ret, dn->full_name);
+ false_positives++;
+ rc = 0;
+ goto dn_unlock;
+ }
+
+ /* If not the kind of error we know about, punt. */
+ if (rets[0] != 2 && rets[0] != 4 && rets[0] != 5) {
+ false_positives++;
+ rc = 0;
+ goto dn_unlock;
+ }
+
+ /* Note that config-io to empty slots may fail;
+ * we recognize empty because they don't have children. */
+ if ((rets[0] == 5) && (dn->child == NULL)) {
+ false_positives++;
+ rc = 0;
+ goto dn_unlock;
+ }
+
+ slot_resets++;
+
+ /* Avoid repeated reports of this failure, including problems
+ * with other functions on this device, and functions under
+ * bridges. */
+ eeh_mark_slot (dn, EEH_MODE_ISOLATED);
+ spin_unlock_irqrestore(&confirm_error_lock, flags);
+
+ state = pci_channel_io_normal;
+ if ((rets[0] == 2) || (rets[0] == 4))
+ state = pci_channel_io_frozen;
+ if (rets[0] == 5)
+ state = pci_channel_io_perm_failure;
+ eeh_send_failure_event (dn, dev, state, rets[2]);
+
+ /* Most EEH events are due to device driver bugs. Having
+ * a stack trace will help the device-driver authors figure
+ * out what happened. So print that out. */
+ if (rets[0] != 5) dump_stack();
+ return 1;
+
+dn_unlock:
+ spin_unlock_irqrestore(&confirm_error_lock, flags);
+ return rc;
+}
+
+EXPORT_SYMBOL_GPL(eeh_dn_check_failure);
+
+/**
+ * eeh_check_failure - check if all 1's data is due to EEH slot freeze
+ * @token i/o token, should be address in the form 0xA....
+ * @val value, should be all 1's (XXX why do we need this arg??)
+ *
+ * Check for an EEH failure at the given token address. Call this
+ * routine if the result of a read was all 0xff's and you want to
+ * find out if this is due to an EEH slot freeze event. This routine
+ * will query firmware for the EEH status.
+ *
+ * Note this routine is safe to call in an interrupt context.
+ */
+unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val)
+{
+ unsigned long addr;
+ struct pci_dev *dev;
+ struct device_node *dn;
+
+ /* Finding the phys addr + pci device; this is pretty quick. */
+ addr = eeh_token_to_phys((unsigned long __force) token);
+ dev = pci_get_device_by_addr(addr);
+ if (!dev) {
+ no_device++;
+ return val;
+ }
+
+ dn = pci_device_to_OF_node(dev);
+ eeh_dn_check_failure (dn, dev);
+
+ pci_dev_put(dev);
+ return val;
+}
+
+EXPORT_SYMBOL(eeh_check_failure);
+
+/* ------------------------------------------------------------- */
+/* The code below deals with error recovery */
+
+/** Return negative value if a permanent error, else return
+ * a number of milliseconds to wait until the PCI slot is
+ * ready to be used.
+ */
+static int
+eeh_slot_availability(struct pci_dn *pdn)
+{
+ int rc;
+ int rets[3];
+
+ rc = read_slot_reset_state(pdn, rets);
+
+ if (rc) return rc;
+
+ if (rets[1] == 0) return -1; /* EEH is not supported */
+ if (rets[0] == 0) return 0; /* Oll Korrect */
+ if (rets[0] == 5) {
+ if (rets[2] == 0) return -1; /* permanently unavailable */
+ return rets[2]; /* number of millisecs to wait */
+ }
+ if (rets[0] == 1)
+ return 250;
+
+ printk (KERN_ERR "EEH: Slot unavailable: rc=%d, rets=%d %d %d\n",
+ rc, rets[0], rets[1], rets[2]);
+ return -1;
+}
+
+/** rtas_pci_slot_reset raises/lowers the pci #RST line
+ * state: 1/0 to raise/lower the #RST
+ *
+ * Clear the EEH-frozen condition on a slot. This routine
+ * asserts the PCI #RST line if the 'state' argument is '1',
+ * and drops the #RST line if 'state is '0'. This routine is
+ * safe to call in an interrupt context.
+ *
+ */
+
+static void
+rtas_pci_slot_reset(struct pci_dn *pdn, int state)
+{
+ int config_addr;
+ int rc;
+
+ BUG_ON (pdn==NULL);
+
+ if (!pdn->phb) {
+ printk (KERN_WARNING "EEH: in slot reset, device node %s has no phb\n",
+ pdn->node->full_name);
+ return;
+ }
+
+ /* Use PE configuration address, if present */
+ config_addr = pdn->eeh_config_addr;
+ if (pdn->eeh_pe_config_addr)
+ config_addr = pdn->eeh_pe_config_addr;
+
+ rc = rtas_call(ibm_set_slot_reset,4,1, NULL,
+ config_addr,
+ BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid),
+ state);
+ if (rc) {
+ printk (KERN_WARNING "EEH: Unable to reset the failed slot, (%d) #RST=%d dn=%s\n",
+ rc, state, pdn->node->full_name);
+ return;
+ }
+}
+
+/** rtas_set_slot_reset -- assert the pci #RST line for 1/4 second
+ * dn -- device node to be reset.
+ *
+ * Return 0 if success, else a non-zero value.
+ */
+
+int
+rtas_set_slot_reset(struct pci_dn *pdn)
+{
+ int i, rc;
+
+ rtas_pci_slot_reset (pdn, 1);
+
+ /* The PCI bus requires that the reset be held high for at least
+ * a 100 milliseconds. We wait a bit longer 'just in case'. */
+
+#define PCI_BUS_RST_HOLD_TIME_MSEC 250
+ msleep (PCI_BUS_RST_HOLD_TIME_MSEC);
+
+ /* We might get hit with another EEH freeze as soon as the
+ * pci slot reset line is dropped. Make sure we don't miss
+ * these, and clear the flag now. */
+ eeh_clear_slot (pdn->node, EEH_MODE_ISOLATED);
+
+ rtas_pci_slot_reset (pdn, 0);
+
+ /* After a PCI slot has been reset, the PCI Express spec requires
+ * a 1.5 second idle time for the bus to stabilize, before starting
+ * up traffic. */
+#define PCI_BUS_SETTLE_TIME_MSEC 1800
+ msleep (PCI_BUS_SETTLE_TIME_MSEC);
+
+ /* Now double check with the firmware to make sure the device is
+ * ready to be used; if not, wait for recovery. */
+ for (i=0; i<10; i++) {
+ rc = eeh_slot_availability (pdn);
+ if (rc < 0)
+ printk (KERN_ERR "EEH: failed (%d) to reset slot %s\n", rc, pdn->node->full_name);
+ if (rc == 0)
+ return 0;
+ if (rc < 0)
+ return -1;
+
+ msleep (rc+100);
+ }
+
+ rc = eeh_slot_availability (pdn);
+ if (rc)
+ printk (KERN_ERR "EEH: timeout resetting slot %s\n", pdn->node->full_name);
+
+ return rc;
+}
+
+/* ------------------------------------------------------- */
+/** Save and restore of PCI BARs
+ *
+ * Although firmware will set up BARs during boot, it doesn't
+ * set up device BAR's after a device reset, although it will,
+ * if requested, set up bridge configuration. Thus, we need to
+ * configure the PCI devices ourselves.
+ */
+
+/**
+ * __restore_bars - Restore the Base Address Registers
+ * Loads the PCI configuration space base address registers,
+ * the expansion ROM base address, the latency timer, and etc.
+ * from the saved values in the device node.
+ */
+static inline void __restore_bars (struct pci_dn *pdn)
+{
+ int i;
+
+ if (NULL==pdn->phb) return;
+ for (i=4; i<10; i++) {
+ rtas_write_config(pdn, i*4, 4, pdn->config_space[i]);
+ }
+
+ /* 12 == Expansion ROM Address */
+ rtas_write_config(pdn, 12*4, 4, pdn->config_space[12]);
+
+#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
+#define SAVED_BYTE(OFF) (((u8 *)(pdn->config_space))[BYTE_SWAP(OFF)])
+
+ rtas_write_config (pdn, PCI_CACHE_LINE_SIZE, 1,
+ SAVED_BYTE(PCI_CACHE_LINE_SIZE));
+
+ rtas_write_config (pdn, PCI_LATENCY_TIMER, 1,
+ SAVED_BYTE(PCI_LATENCY_TIMER));
+
+ /* max latency, min grant, interrupt pin and line */
+ rtas_write_config(pdn, 15*4, 4, pdn->config_space[15]);
+}
+
+/**
+ * eeh_restore_bars - restore the PCI config space info
+ *
+ * This routine performs a recursive walk to the children
+ * of this device as well.
+ */
+void eeh_restore_bars(struct pci_dn *pdn)
+{
+ struct device_node *dn;
+ if (!pdn)
+ return;
+
+ if ((pdn->eeh_mode & EEH_MODE_SUPPORTED) && !IS_BRIDGE(pdn->class_code))
+ __restore_bars (pdn);
+
+ dn = pdn->node->child;
+ while (dn) {
+ eeh_restore_bars (PCI_DN(dn));
+ dn = dn->sibling;
+ }
+}
+
+/**
+ * eeh_save_bars - save device bars
+ *
+ * Save the values of the device bars. Unlike the restore
+ * routine, this routine is *not* recursive. This is because
+ * PCI devices are added individuallly; but, for the restore,
+ * an entire slot is reset at a time.
+ */
+static void eeh_save_bars(struct pci_dn *pdn)
+{
+ int i;
+
+ if (!pdn )
+ return;
+
+ for (i = 0; i < 16; i++)
+ rtas_read_config(pdn, i * 4, 4, &pdn->config_space[i]);
+}
+
+void
+rtas_configure_bridge(struct pci_dn *pdn)
+{
+ int config_addr;
+ int rc;
+
+ /* Use PE configuration address, if present */
+ config_addr = pdn->eeh_config_addr;
+ if (pdn->eeh_pe_config_addr)
+ config_addr = pdn->eeh_pe_config_addr;
+
+ rc = rtas_call(ibm_configure_bridge,3,1, NULL,
+ config_addr,
+ BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid));
+ if (rc) {
+ printk (KERN_WARNING "EEH: Unable to configure device bridge (%d) for %s\n",
+ rc, pdn->node->full_name);
+ }
+}
+
+/* ------------------------------------------------------------- */
+/* The code below deals with enabling EEH for devices during the
+ * early boot sequence. EEH must be enabled before any PCI probing
+ * can be done.
+ */
+
+#define EEH_ENABLE 1
+
+struct eeh_early_enable_info {
+ unsigned int buid_hi;
+ unsigned int buid_lo;
+};
+
+/* Enable eeh for the given device node. */
+static void *early_enable_eeh(struct device_node *dn, void *data)
+{
+ struct eeh_early_enable_info *info = data;
+ int ret;
+ char *status = get_property(dn, "status", NULL);
+ u32 *class_code = (u32 *)get_property(dn, "class-code", NULL);
+ u32 *vendor_id = (u32 *)get_property(dn, "vendor-id", NULL);
+ u32 *device_id = (u32 *)get_property(dn, "device-id", NULL);
+ u32 *regs;
+ int enable;
+ struct pci_dn *pdn = PCI_DN(dn);
+
+ pdn->class_code = 0;
+ pdn->eeh_mode = 0;
+ pdn->eeh_check_count = 0;
+ pdn->eeh_freeze_count = 0;
+
+ if (status && strcmp(status, "ok") != 0)
+ return NULL; /* ignore devices with bad status */
+
+ /* Ignore bad nodes. */
+ if (!class_code || !vendor_id || !device_id)
+ return NULL;
+
+ /* There is nothing to check on PCI to ISA bridges */
+ if (dn->type && !strcmp(dn->type, "isa")) {
+ pdn->eeh_mode |= EEH_MODE_NOCHECK;
+ return NULL;
+ }
+ pdn->class_code = *class_code;
+
+ /*
+ * Now decide if we are going to "Disable" EEH checking
+ * for this device. We still run with the EEH hardware active,
+ * but we won't be checking for ff's. This means a driver
+ * could return bad data (very bad!), an interrupt handler could
+ * hang waiting on status bits that won't change, etc.
+ * But there are a few cases like display devices that make sense.
+ */
+ enable = 1; /* i.e. we will do checking */
+#if 0
+ if ((*class_code >> 16) == PCI_BASE_CLASS_DISPLAY)
+ enable = 0;
+#endif
+
+ if (!enable)
+ pdn->eeh_mode |= EEH_MODE_NOCHECK;
+
+ /* Ok... see if this device supports EEH. Some do, some don't,
+ * and the only way to find out is to check each and every one. */
+ regs = (u32 *)get_property(dn, "reg", NULL);
+ if (regs) {
+ /* First register entry is addr (00BBSS00) */
+ /* Try to enable eeh */
+ ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
+ regs[0], info->buid_hi, info->buid_lo,
+ EEH_ENABLE);
+
+ if (ret == 0) {
+ eeh_subsystem_enabled = 1;
+ pdn->eeh_mode |= EEH_MODE_SUPPORTED;
+ pdn->eeh_config_addr = regs[0];
+
+ /* If the newer, better, ibm,get-config-addr-info is supported,
+ * then use that instead. */
+ pdn->eeh_pe_config_addr = 0;
+ if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
+ unsigned int rets[2];
+ ret = rtas_call (ibm_get_config_addr_info, 4, 2, rets,
+ pdn->eeh_config_addr,
+ info->buid_hi, info->buid_lo,
+ 0);
+ if (ret == 0)
+ pdn->eeh_pe_config_addr = rets[0];
+ }
+#ifdef DEBUG
+ printk(KERN_DEBUG "EEH: %s: eeh enabled, config=%x pe_config=%x\n",
+ dn->full_name, pdn->eeh_config_addr, pdn->eeh_pe_config_addr);
+#endif
+ } else {
+
+ /* This device doesn't support EEH, but it may have an
+ * EEH parent, in which case we mark it as supported. */
+ if (dn->parent && PCI_DN(dn->parent)
+ && (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) {
+ /* Parent supports EEH. */
+ pdn->eeh_mode |= EEH_MODE_SUPPORTED;
+ pdn->eeh_config_addr = PCI_DN(dn->parent)->eeh_config_addr;
+ return NULL;
+ }
+ }
+ } else {
+ printk(KERN_WARNING "EEH: %s: unable to get reg property.\n",
+ dn->full_name);
+ }
+
+ eeh_save_bars(pdn);
+ return NULL;
+}
+
+/*
+ * Initialize EEH by trying to enable it for all of the adapters in the system.
+ * As a side effect we can determine here if eeh is supported at all.
+ * Note that we leave EEH on so failed config cycles won't cause a machine
+ * check. If a user turns off EEH for a particular adapter they are really
+ * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't
+ * grant access to a slot if EEH isn't enabled, and so we always enable
+ * EEH for all slots/all devices.
+ *
+ * The eeh-force-off option disables EEH checking globally, for all slots.
+ * Even if force-off is set, the EEH hardware is still enabled, so that
+ * newer systems can boot.
+ */
+void __init eeh_init(void)
+{
+ struct device_node *phb, *np;
+ struct eeh_early_enable_info info;
+
+ spin_lock_init(&confirm_error_lock);
+ spin_lock_init(&slot_errbuf_lock);
+
+ np = of_find_node_by_path("/rtas");
+ if (np == NULL)
+ return;
+
+ ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
+ ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
+ ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2");
+ ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state");
+ ibm_slot_error_detail = rtas_token("ibm,slot-error-detail");
+ ibm_get_config_addr_info = rtas_token("ibm,get-config-addr-info");
+ ibm_configure_bridge = rtas_token ("ibm,configure-bridge");
+
+ if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE)
+ return;
+
+ eeh_error_buf_size = rtas_token("rtas-error-log-max");
+ if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
+ eeh_error_buf_size = 1024;
+ }
+ if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
+ printk(KERN_WARNING "EEH: rtas-error-log-max is bigger than allocated "
+ "buffer ! (%d vs %d)", eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
+ eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
+ }
+
+ /* Enable EEH for all adapters. Note that eeh requires buid's */
+ for (phb = of_find_node_by_name(NULL, "pci"); phb;
+ phb = of_find_node_by_name(phb, "pci")) {
+ unsigned long buid;
+
+ buid = get_phb_buid(phb);
+ if (buid == 0 || PCI_DN(phb) == NULL)
+ continue;
+
+ info.buid_lo = BUID_LO(buid);
+ info.buid_hi = BUID_HI(buid);
+ traverse_pci_devices(phb, early_enable_eeh, &info);
+ }
+
+ if (eeh_subsystem_enabled)
+ printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n");
+ else
+ printk(KERN_WARNING "EEH: No capable adapters found\n");
+}
+
+/**
+ * eeh_add_device_early - enable EEH for the indicated device_node
+ * @dn: device node for which to set up EEH
+ *
+ * This routine must be used to perform EEH initialization for PCI
+ * devices that were added after system boot (e.g. hotplug, dlpar).
+ * This routine must be called before any i/o is performed to the
+ * adapter (inluding any config-space i/o).
+ * Whether this actually enables EEH or not for this device depends
+ * on the CEC architecture, type of the device, on earlier boot
+ * command-line arguments & etc.
+ */
+static void eeh_add_device_early(struct device_node *dn)
+{
+ struct pci_controller *phb;
+ struct eeh_early_enable_info info;
+
+ if (!dn || !PCI_DN(dn))
+ return;
+ phb = PCI_DN(dn)->phb;
+
+ /* USB Bus children of PCI devices will not have BUID's */
+ if (NULL == phb || 0 == phb->buid)
+ return;
+
+ info.buid_hi = BUID_HI(phb->buid);
+ info.buid_lo = BUID_LO(phb->buid);
+ early_enable_eeh(dn, &info);
+}
+
+void eeh_add_device_tree_early(struct device_node *dn)
+{
+ struct device_node *sib;
+ for (sib = dn->child; sib; sib = sib->sibling)
+ 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 pci_dn *pdn;
+
+ if (!dev || !eeh_subsystem_enabled)
+ return;
+
+#ifdef DEBUG
+ printk(KERN_DEBUG "EEH: adding device %s\n", pci_name(dev));
+#endif
+
+ pci_dev_get (dev);
+ dn = pci_device_to_OF_node(dev);
+ pdn = PCI_DN(dn);
+ pdn->pcidev = dev;
+
+ pci_addr_cache_insert_device (dev);
+}
+
+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_remove_device - undo EEH setup for the indicated pci device
+ * @dev: pci device to be removed
+ *
+ * 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)
+{
+ struct device_node *dn;
+ if (!dev || !eeh_subsystem_enabled)
+ return;
+
+ /* Unregister the device with the EEH/PCI address search system */
+#ifdef DEBUG
+ printk(KERN_DEBUG "EEH: remove device %s\n", pci_name(dev));
+#endif
+ pci_addr_cache_remove_device(dev);
+
+ dn = pci_device_to_OF_node(dev);
+ if (PCI_DN(dn)->pcidev) {
+ PCI_DN(dn)->pcidev = NULL;
+ pci_dev_put (dev);
+ }
+}
+
+void eeh_remove_bus_device(struct pci_dev *dev)
+{
+ struct pci_bus *bus = dev->subordinate;
+ struct pci_dev *child, *tmp;
+
+ eeh_remove_device(dev);
+
+ 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);
+ }
+}
+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=%ld\n", total_mmio_ffs);
+ } else {
+ seq_printf(m, "EEH Subsystem is enabled\n");
+ seq_printf(m,
+ "no device=%ld\n"
+ "no device node=%ld\n"
+ "no config address=%ld\n"
+ "check not wanted=%ld\n"
+ "eeh_total_mmio_ffs=%ld\n"
+ "eeh_false_positives=%ld\n"
+ "eeh_ignored_failures=%ld\n"
+ "eeh_slot_resets=%ld\n",
+ no_device, no_dn, no_cfg_addr,
+ ignored_check, total_mmio_ffs,
+ false_positives, ignored_failures,
+ slot_resets);
+ }
+
+ return 0;
+}
+
+static int proc_eeh_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, proc_eeh_show, NULL);
+}
+
+static struct file_operations proc_eeh_operations = {
+ .open = proc_eeh_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init eeh_init_proc(void)
+{
+ struct proc_dir_entry *e;
+
+ if (machine_is(pseries)) {
+ e = create_proc_entry("ppc64/eeh", 0, NULL);
+ if (e)
+ e->proc_fops = &proc_eeh_operations;
+ }
+
+ return 0;
+}
+__initcall(eeh_init_proc);
git://git.onelab.eu / linux-2.6.git / blobdiff