/*
 * 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/init.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>
#include <asm/paca.h>
#include <asm/processor.h>
#include <asm/naca.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/rtas.h>
#include "pci.h"

#undef DEBUG

#define BUID_HI(buid) ((buid) >> 32)
#define BUID_LO(buid) ((buid) & 0xffffffff)
#define CONFIG_ADDR(busno, devfn) \
                (((((busno) & 0xff) << 8) | ((devfn) & 0xf8)) << 8)

/* RTAS tokens */
static int ibm_set_eeh_option;
static int ibm_set_slot_reset;
static int ibm_read_slot_reset_state;
static int ibm_slot_error_detail;

static int eeh_subsystem_enabled;
#define EEH_MAX_OPTS 4096
static char *eeh_opts;
static int eeh_opts_last;

/* Buffer for reporting slot-error-detail rtas calls */
static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
static spinlock_t slot_errbuf_lock = SPIN_LOCK_UNLOCKED;
static int eeh_error_buf_size;

/* System monitoring statistics */
static DEFINE_PER_CPU(unsigned long, total_mmio_ffs);
static DEFINE_PER_CPU(unsigned long, false_positives);
static DEFINE_PER_CPU(unsigned long, ignored_failures);

static int eeh_check_opts_config(struct device_node *dn, int class_code,
                                 int vendor_id, int device_id,
                                 int default_state);

/**
 * The pci address cache subsystem.  This subsystem places
 * PCI device address resources into a red-black tree, sorted
 * according to the address range, so that given only an i/o
 * address, the corresponding PCI device can be **quickly**
 * found.
 *
 * Currently, the only customer of this code is the EEH subsystem;
 * thus, this code has been somewhat tailored to suit EEH better.
 * In particular, the cache does *not* hold the addresses of devices
 * for which EEH is not enabled.
 *
 * (Implementation Note: The RB tree seems to be better/faster
 * than any hash algo I could think of for this problem, even
 * with the penalty of slow pointer chases for d-cache misses).
 */
struct pci_io_addr_range
{
        struct rb_node rb_node;
        unsigned long addr_lo;
        unsigned long addr_hi;
        struct pci_dev *pcidev;
        unsigned int flags;
};

static struct pci_io_addr_cache
{
        struct rb_root rb_root;
        spinlock_t piar_lock;
} pci_io_addr_cache_root;

static inline struct pci_dev *__pci_get_device_by_addr(unsigned long addr)
{
        struct rb_node *n = pci_io_addr_cache_root.rb_root.rb_node;

        while (n) {
                struct pci_io_addr_range *piar;
                piar = rb_entry(n, struct pci_io_addr_range, rb_node);

                if (addr < piar->addr_lo) {
                        n = n->rb_left;
                } else {
                        if (addr > piar->addr_hi) {
                                n = n->rb_right;
                        } else {
                                pci_dev_get(piar->pcidev);
                                return piar->pcidev;
                        }
                }
        }

        return NULL;
}

/**
 * pci_get_device_by_addr - Get device, given only address
 * @addr: mmio (PIO) phys address or i/o port number
 *
 * Given an mmio phys address, or a port number, find a pci device
 * that implements this address.  Be sure to pci_dev_put the device
 * when finished.  I/O port numbers are assumed to be offset
 * from zero (that is, they do *not* have pci_io_addr added in).
 * It is safe to call this function within an interrupt.
 */
static struct pci_dev *pci_get_device_by_addr(unsigned long addr)
{
        struct pci_dev *dev;
        unsigned long flags;

        spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
        dev = __pci_get_device_by_addr(addr);
        spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
        return dev;
}

#ifdef DEBUG
/*
 * Handy-dandy debug print routine, does nothing more
 * than print out the contents of our addr cache.
 */
static void pci_addr_cache_print(struct pci_io_addr_cache *cache)
{
        struct rb_node *n;
        int cnt = 0;

        n = rb_first(&cache->rb_root);
        while (n) {
                struct pci_io_addr_range *piar;
                piar = rb_entry(n, struct pci_io_addr_range, rb_node);
                printk(KERN_DEBUG "PCI: %s addr range %d [%lx-%lx]: %s %s\n",
                       (piar->flags & IORESOURCE_IO) ? "i/o" : "mem", cnt,
                       piar->addr_lo, piar->addr_hi, pci_name(piar->pcidev),
                       pci_pretty_name(piar->pcidev));
                cnt++;
                n = rb_next(n);
        }
}
#endif

/* Insert address range into the rb tree. */
static struct pci_io_addr_range *
pci_addr_cache_insert(struct pci_dev *dev, unsigned long alo,
                      unsigned long ahi, unsigned int flags)
{
        struct rb_node **p = &pci_io_addr_cache_root.rb_root.rb_node;
        struct rb_node *parent = NULL;
        struct pci_io_addr_range *piar;

        /* Walk tree, find a place to insert into tree */
        while (*p) {
                parent = *p;
                piar = rb_entry(parent, struct pci_io_addr_range, rb_node);
                if (alo < piar->addr_lo) {
                        p = &parent->rb_left;
                } else if (ahi > piar->addr_hi) {
                        p = &parent->rb_right;
                } else {
                        if (dev != piar->pcidev ||
                            alo != piar->addr_lo || ahi != piar->addr_hi) {
                                printk(KERN_WARNING "PIAR: overlapping address range\n");
                        }
                        return piar;
                }
        }
        piar = (struct pci_io_addr_range *)kmalloc(sizeof(struct pci_io_addr_range), GFP_ATOMIC);
        if (!piar)
                return NULL;

        piar->addr_lo = alo;
        piar->addr_hi = ahi;
        piar->pcidev = dev;
        piar->flags = flags;

        rb_link_node(&piar->rb_node, parent, p);
        rb_insert_color(&piar->rb_node, &pci_io_addr_cache_root.rb_root);

        return piar;
}

static void __pci_addr_cache_insert_device(struct pci_dev *dev)
{
        struct device_node *dn;
        int i;

        dn = pci_device_to_OF_node(dev);
        if (!dn) {
                printk(KERN_WARNING "PCI: no pci dn found for dev=%s %s\n",
                        pci_name(dev), pci_pretty_name(dev));
                return;
        }

        /* Skip any devices for which EEH is not enabled. */
        if (!(dn->eeh_mode & EEH_MODE_SUPPORTED) ||
            dn->eeh_mode & EEH_MODE_NOCHECK) {
#ifdef DEBUG
                printk(KERN_INFO "PCI: skip building address cache for=%s %s\n",
                       pci_name(dev), pci_pretty_name(dev));
#endif
                return;
        }

        /* The cache holds a reference to the device... */
        pci_dev_get(dev);

        /* Walk resources on this device, poke them into the tree */
        for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
                unsigned long start = pci_resource_start(dev,i);
                unsigned long end = pci_resource_end(dev,i);
                unsigned int flags = pci_resource_flags(dev,i);

                /* We are interested only bus addresses, not dma or other stuff */
                if (0 == (flags & (IORESOURCE_IO | IORESOURCE_MEM)))
                        continue;
                if (start == 0 || ~start == 0 || end == 0 || ~end == 0)
                         continue;
                pci_addr_cache_insert(dev, start, end, flags);
        }
}

/**
 * pci_addr_cache_insert_device - Add a device to the address cache
 * @dev: PCI device whose I/O addresses we are interested in.
 *
 * In order to support the fast lookup of devices based on addresses,
 * we maintain a cache of devices that can be quickly searched.
 * This routine adds a device to that cache.
 */
void pci_addr_cache_insert_device(struct pci_dev *dev)
{
        unsigned long flags;

        spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
        __pci_addr_cache_insert_device(dev);
        spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
}

static inline void __pci_addr_cache_remove_device(struct pci_dev *dev)
{
        struct rb_node *n;

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);
                        kfree(piar);
                        goto restart;
                }
                n = rb_next(n);
        }

        /* The cache no longer holds its reference to this device... */
        pci_dev_put(dev);
}

/**
 * pci_addr_cache_remove_device - remove pci device from addr cache
 * @dev: device to remove
 *
 * Remove a device from the addr-cache tree.
 * This is potentially expensive, since it will walk
 * the tree multiple times (once per resource).
 * But so what; device removal doesn't need to be that fast.
 */
void pci_addr_cache_remove_device(struct pci_dev *dev)
{
        unsigned long flags;

        spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
        __pci_addr_cache_remove_device(dev);
        spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
}

/**
 * pci_addr_cache_build - Build a cache of I/O addresses
 *
 * Build a cache of pci i/o addresses.  This cache will be used to
 * find the pci device that corresponds to a given address.
 * This routine scans all pci busses to build the cache.
 * Must be run late in boot process, after the pci controllers
 * have been scaned for devices (after all device resources are known).
 */
void __init pci_addr_cache_build(void)
{
        struct pci_dev *dev = NULL;

        spin_lock_init(&pci_io_addr_cache_root.piar_lock);

        while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
                /* Ignore PCI bridges ( XXX why ??) */
                if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE) {
                        continue;
                }
                pci_addr_cache_insert_device(dev);
        }

#ifdef DEBUG
        /* Verify tree built up above, echo back the list of addrs. */
        pci_addr_cache_print(&pci_io_addr_cache_root);
#endif
}

/**
 * eeh_token_to_phys - convert EEH address token to phys address
 * @token i/o token, should be address in the form 0xA....
 *
 * Converts EEH address tokens into physical addresses.  Note that
 * ths routine does *not* convert I/O BAR addresses (which start
 * with 0xE...) to phys addresses!
 */
static unsigned long eeh_token_to_phys(unsigned long token)
{
        pte_t *ptep;
        unsigned long pa, vaddr;

        if (REGION_ID(token) == EEH_REGION_ID)
                vaddr = IO_TOKEN_TO_ADDR(token);
        else
                return token;

        ptep = find_linux_pte(ioremap_mm.pgd, vaddr);
        pa = pte_pfn(*ptep) << PAGE_SHIFT;

        return pa | (vaddr & (PAGE_SIZE-1));
}

/**
 * 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.
 * The given value has been read and it should be 1's (0xff, 0xffff or
 * 0xffffffff).
 *
 * Probe to determine if an error actually occurred.  If not return val.
 * Otherwise panic.
 *
 * Note this routine might be called in an interrupt context ...
 */
unsigned long eeh_check_failure(void *token, unsigned long val)
{
        unsigned long addr;
        struct pci_dev *dev;
        struct device_node *dn;
        int ret;
        int rets[2];
        unsigned long flags;

        __get_cpu_var(total_mmio_ffs)++;

        if (!eeh_subsystem_enabled)
                return val;

        /* Finding the phys addr + pci device; this is pretty quick. */
        addr = eeh_token_to_phys((unsigned long)token);
        dev = pci_get_device_by_addr(addr);
        if (!dev)
                return val;

        dn = pci_device_to_OF_node(dev);
        if (!dn) {
                pci_dev_put(dev);
                return val;
        }

        /* Access to IO BARs might get this far and still not want checking. */
        if (!(dn->eeh_mode & EEH_MODE_SUPPORTED) ||
            dn->eeh_mode & EEH_MODE_NOCHECK) {
                pci_dev_put(dev);
                return val;
        }

        if (!dn->eeh_config_addr) {
                pci_dev_put(dev);
                return val;
        }

        /*
         * Now test for an EEH failure.  This is VERY expensive.
         * Note that the eeh_config_addr may be a parent device
         * in the case of a device behind a bridge, or it may be
         * function zero of a multi-function device.
         * In any case they must share a common PHB.
         */
        ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
                        dn->eeh_config_addr, BUID_HI(dn->phb->buid),
                        BUID_LO(dn->phb->buid));

        if (ret == 0 && rets[1] == 1 && rets[0] >= 2) {
                int log_event;

                spin_lock_irqsave(&slot_errbuf_lock, flags);
                memset(slot_errbuf, 0, eeh_error_buf_size);

                log_event = rtas_call(ibm_slot_error_detail,
                                      8, 1, NULL, dn->eeh_config_addr,
                                      BUID_HI(dn->phb->buid),
                                      BUID_LO(dn->phb->buid), NULL, 0,
                                      virt_to_phys(slot_errbuf),
                                      eeh_error_buf_size,
                                      2 /* Permanent Error */);

                if (log_event == 0)
                        log_error(slot_errbuf, ERR_TYPE_RTAS_LOG,
                                  1 /* Fatal */);

                spin_unlock_irqrestore(&slot_errbuf_lock, flags);

                /*
                 * XXX We should create a separate sysctl for this.
                 *
                 * Since the panic_on_oops sysctl is used to halt
                 * the system in light of potential corruption, we
                 * can use it here.
                 */
                if (panic_on_oops) {
                        panic("EEH: MMIO failure (%d) on device:%s %s\n",
                              rets[0], pci_name(dev), pci_pretty_name(dev));
                } else {
                        __get_cpu_var(ignored_failures)++;
                        printk(KERN_INFO "EEH: MMIO failure (%d) on device:%s %s\n",
                               rets[0], pci_name(dev), pci_pretty_name(dev));
                }
        } else {
                __get_cpu_var(false_positives)++;
        }

        pci_dev_put(dev);
        return val;
}
EXPORT_SYMBOL(eeh_check_failure);

struct eeh_early_enable_info {
        unsigned int buid_hi;
        unsigned int buid_lo;
        int force_off;
};

/* Enable eeh for the given device node. */
static void *early_enable_eeh(struct device_node *dn, void *data)
{
        struct eeh_early_enable_info *info = data;
        int ret;
        char *status = get_property(dn, "status", NULL);
        u32 *class_code = (u32 *)get_property(dn, "class-code", NULL);
        u32 *vendor_id = (u32 *)get_property(dn, "vendor-id", NULL);
        u32 *device_id = (u32 *)get_property(dn, "device-id", NULL);
        u32 *regs;
        int enable;

        dn->eeh_mode = 0;

        if (status && strcmp(status, "ok") != 0)
                return NULL;    /* ignore devices with bad status */

        /* Ignore bad nodes. */
        if (!class_code || !vendor_id || !device_id)
                return NULL;

        /* There is nothing to check on PCI to ISA bridges */
        if (dn->type && !strcmp(dn->type, "isa")) {
                dn->eeh_mode |= EEH_MODE_NOCHECK;
                return NULL;
        }

        /*
         * Now decide if we are going to "Disable" EEH checking
         * for this device.  We still run with the EEH hardware active,
         * but we won't be checking for ff's.  This means a driver
         * could return bad data (very bad!), an interrupt handler could
         * hang waiting on status bits that won't change, etc.
         * But there are a few cases like display devices that make sense.
         */
        enable = 1;     /* i.e. we will do checking */
        if ((*class_code >> 16) == PCI_BASE_CLASS_DISPLAY)
                enable = 0;

        if (!eeh_check_opts_config(dn, *class_code, *vendor_id, *device_id,
                                   enable)) {
                if (enable) {
                        printk(KERN_WARNING "EEH: %s user requested to run "
                               "without EEH checking.\n", dn->full_name);
                        enable = 0;
                }
        }

        if (!enable || info->force_off) {
                dn->eeh_mode |= EEH_MODE_NOCHECK;
        }

        /* Ok... see if this device supports EEH.  Some do, some don't,
         * and the only way to find out is to check each and every one. */
        regs = (u32 *)get_property(dn, "reg", NULL);
        if (regs) {
                /* First register entry is addr (00BBSS00)  */
                /* Try to enable eeh */
                ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
                                regs[0], info->buid_hi, info->buid_lo,
                                EEH_ENABLE);
                if (ret == 0) {
                        eeh_subsystem_enabled = 1;
                        dn->eeh_mode |= EEH_MODE_SUPPORTED;
                        dn->eeh_config_addr = regs[0];
#ifdef DEBUG
                        printk(KERN_DEBUG "EEH: %s: eeh enabled\n", dn->full_name);
#endif
                } else {

                        /* This device doesn't support EEH, but it may have an
                         * EEH parent, in which case we mark it as supported. */
                        if (dn->parent && (dn->parent->eeh_mode & EEH_MODE_SUPPORTED)) {
                                /* Parent supports EEH. */
                                dn->eeh_mode |= EEH_MODE_SUPPORTED;
                                dn->eeh_config_addr = dn->parent->eeh_config_addr;
                                return NULL;
                        }
                }
        } else {
                printk(KERN_WARNING "EEH: %s: unable to get reg property.\n",
                       dn->full_name);
        }

        return NULL; 
}

/*
 * Initialize EEH by trying to enable it for all of the adapters in the system.
 * As a side effect we can determine here if eeh is supported at all.
 * Note that we leave EEH on so failed config cycles won't cause a machine
 * check.  If a user turns off EEH for a particular adapter they are really
 * telling Linux to ignore errors.  Some hardware (e.g. POWER5) won't
 * grant access to a slot if EEH isn't enabled, and so we always enable
 * EEH for all slots/all devices.
 *
 * The eeh-force-off option disables EEH checking globally, for all slots.
 * Even if force-off is set, the EEH hardware is still enabled, so that
 * newer systems can boot.
 */
void __init eeh_init(void)
{
        struct device_node *phb, *np;
        struct eeh_early_enable_info info;
        char *eeh_force_off = strstr(saved_command_line, "eeh-force-off");

        init_pci_config_tokens();

        np = of_find_node_by_path("/rtas");
        if (np == NULL) {
                printk(KERN_WARNING "EEH: RTAS not found !\n");
                return;
        }

        ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
        ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
        ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state");
        ibm_slot_error_detail = rtas_token("ibm,slot-error-detail");

        if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE)
                return;

        eeh_error_buf_size = rtas_token("rtas-error-log-max");
        if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
                eeh_error_buf_size = 1024;
        }
        if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
                printk(KERN_WARNING "EEH: rtas-error-log-max is bigger than allocated "
                      "buffer ! (%d vs %d)", eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
                eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
        }

        info.force_off = 0;
        if (eeh_force_off) {
                printk(KERN_WARNING "EEH: WARNING: PCI Enhanced I/O Error "
                       "Handling is user disabled\n");
                info.force_off = 1;
        }

        /* Enable EEH for all adapters.  Note that eeh requires buid's */
        for (phb = of_find_node_by_name(NULL, "pci"); phb;
             phb = of_find_node_by_name(phb, "pci")) {
                unsigned long buid;

                buid = get_phb_buid(phb);
                if (buid == 0)
                        continue;

                info.buid_lo = BUID_LO(buid);
                info.buid_hi = BUID_HI(buid);
                traverse_pci_devices(phb, early_enable_eeh, &info);
        }

        if (eeh_subsystem_enabled) {
                printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n");
        } else {
                printk(KERN_WARNING "EEH: disabled PCI Enhanced I/O Error Handling\n");
        }
}

/**
 * eeh_add_device_early - enable EEH for the indicated device_node
 * @dn: device node for which to set up EEH
 *
 * This routine must be used to perform EEH initialization for PCI
 * devices that were added after system boot (e.g. hotplug, dlpar).
 * This routine must be called before any i/o is performed to the
 * adapter (inluding any config-space i/o).
 * Whether this actually enables EEH or not for this device depends
 * on the CEC architecture, type of the device, on earlier boot
 * command-line arguments & etc.
 */
void eeh_add_device_early(struct device_node *dn)
{
        struct pci_controller *phb;
        struct eeh_early_enable_info info;

        if (!dn || !eeh_subsystem_enabled)
                return;
        phb = dn->phb;
        if (NULL == phb || 0 == phb->buid) {
                printk(KERN_WARNING "EEH: Expected buid but found none\n");
                return;
        }

        info.buid_hi = BUID_HI(phb->buid);
        info.buid_lo = BUID_LO(phb->buid);
        early_enable_eeh(dn, &info);
}
EXPORT_SYMBOL(eeh_add_device_early);

/**
 * eeh_add_device_late - perform EEH initialization for the indicated pci device
 * @dev: pci device for which to set up EEH
 *
 * This routine must be used to complete EEH initialization for PCI
 * devices that were added after system boot (e.g. hotplug, dlpar).
 */
void eeh_add_device_late(struct pci_dev *dev)
{
        if (!dev || !eeh_subsystem_enabled)
                return;

#ifdef DEBUG
        printk(KERN_DEBUG "EEH: adding device %s %s\n", pci_name(dev),
               pci_pretty_name(dev));
#endif

        pci_addr_cache_insert_device (dev);
}
EXPORT_SYMBOL(eeh_add_device_late);

/**
 * eeh_remove_device - undo EEH setup for the indicated pci device
 * @dev: pci device to be removed
 *
 * This routine should be when a device is removed from a running
 * system (e.g. by hotplug or dlpar).
 */
void eeh_remove_device(struct pci_dev *dev)
{
        if (!dev || !eeh_subsystem_enabled)
                return;

        /* Unregister the device with the EEH/PCI address search system */
#ifdef DEBUG
        printk(KERN_DEBUG "EEH: remove device %s %s\n", pci_name(dev),
               pci_pretty_name(dev));
#endif
        pci_addr_cache_remove_device(dev);
}
EXPORT_SYMBOL(eeh_remove_device);

/*
 * If EEH is implemented, find the PCI device using given phys addr
 * and check to see if eeh failure checking is disabled.
 * Remap the addr (trivially) to the EEH region if EEH checking enabled.
 * For addresses not known to PCI the vaddr is simply returned unchanged.
 */
void *eeh_ioremap(unsigned long addr, void *vaddr)
{
        struct pci_dev *dev;
        struct device_node *dn;

        if (!eeh_subsystem_enabled)
                return vaddr;

        dev = pci_get_device_by_addr(addr);
        if (!dev)
                return vaddr;

        dn = pci_device_to_OF_node(dev);
        if (!dn) {
                pci_dev_put(dev);
                return vaddr;
        }

        if (dn->eeh_mode & EEH_MODE_NOCHECK) {
                pci_dev_put(dev);
                return vaddr;
        }

        pci_dev_put(dev);
        return (void *)IO_ADDR_TO_TOKEN(vaddr);
}

static int proc_eeh_show(struct seq_file *m, void *v)
{
        unsigned int cpu;
        unsigned long ffs = 0, positives = 0, failures = 0;

        for_each_cpu(cpu) {
                ffs += per_cpu(total_mmio_ffs, cpu);
                positives += per_cpu(false_positives, cpu);
                failures += per_cpu(ignored_failures, cpu);
        }

        if (0 == eeh_subsystem_enabled) {
                seq_printf(m, "EEH Subsystem is globally disabled\n");
                seq_printf(m, "eeh_total_mmio_ffs=%ld\n", ffs);
        } else {
                seq_printf(m, "EEH Subsystem is enabled\n");
                seq_printf(m, "eeh_total_mmio_ffs=%ld\n"
                           "eeh_false_positives=%ld\n"
                           "eeh_ignored_failures=%ld\n",
                           ffs, positives, failures);
        }

        return 0;
}

static int proc_eeh_open(struct inode *inode, struct file *file)
{
        return single_open(file, proc_eeh_show, NULL);
}

static struct file_operations proc_eeh_operations = {
        .open      = proc_eeh_open,
        .read      = seq_read,
        .llseek    = seq_lseek,
        .release   = single_release,
};

static int __init eeh_init_proc(void)
{
        struct proc_dir_entry *e;

        if (systemcfg->platform & PLATFORM_PSERIES) {
                e = create_proc_entry("ppc64/eeh", 0, NULL);
                if (e)
                        e->proc_fops = &proc_eeh_operations;
        }

        return 0;
}
__initcall(eeh_init_proc);

/*
 * Test if "dev" should be configured on or off.
 * This processes the options literally from left to right.
 * This lets the user specify stupid combinations of options,
 * but at least the result should be very predictable.
 */
static int eeh_check_opts_config(struct device_node *dn,
                                 int class_code, int vendor_id, int device_id,
                                 int default_state)
{
        char devname[32], classname[32];
        char *strs[8], *s;
        int nstrs, i;
        int ret = default_state;

        /* Build list of strings to match */
        nstrs = 0;
        s = (char *)get_property(dn, "ibm,loc-code", NULL);
        if (s)
                strs[nstrs++] = s;
        sprintf(devname, "dev%04x:%04x", vendor_id, device_id);
        strs[nstrs++] = devname;
        sprintf(classname, "class%04x", class_code);
        strs[nstrs++] = classname;
        strs[nstrs++] = "";     /* yes, this matches the empty string */

        /*
         * Now see if any string matches the eeh_opts list.
         * The eeh_opts list entries start with + or -.
         */
        for (s = eeh_opts; s && (s < (eeh_opts + eeh_opts_last));
             s += strlen(s)+1) {
                for (i = 0; i < nstrs; i++) {
                        if (strcasecmp(strs[i], s+1) == 0) {
                                ret = (strs[i][0] == '+') ? 1 : 0;
                        }
                }
        }
        return ret;
}

/*
 * Handle kernel eeh-on & eeh-off cmd line options for eeh.
 *
 * We support:
 *      eeh-off=loc1,loc2,loc3...
 *
 * and this option can be repeated so
 *      eeh-off=loc1,loc2 eeh-off=loc3
 * is the same as eeh-off=loc1,loc2,loc3
 *
 * loc is an IBM location code that can be found in a manual or
 * via openfirmware (or the Hardware Management Console).
 *
 * We also support these additional "loc" values:
 *
 *      dev#:#    vendor:device id in hex (e.g. dev1022:2000)
 *      class#    class id in hex (e.g. class0200)
 *
 * If no location code is specified all devices are assumed
 * so eeh-off means eeh by default is off.
 */

/*
 * This is implemented as a null separated list of strings.
 * Each string looks like this:  "+X" or "-X"
 * where X is a loc code, vendor:device, class (as shown above)
 * or empty which is used to indicate all.
 *
 * We interpret this option string list so that it will literally
 * behave left-to-right even if some combinations don't make sense.
 */
static int __init eeh_parm(char *str, int state)
{
        char *s, *cur, *curend;

        if (!eeh_opts) {
                eeh_opts = alloc_bootmem(EEH_MAX_OPTS);
                eeh_opts[eeh_opts_last++] = '+'; /* default */
                eeh_opts[eeh_opts_last++] = '\0';
        }
        if (*str == '\0') {
                eeh_opts[eeh_opts_last++] = state ? '+' : '-';
                eeh_opts[eeh_opts_last++] = '\0';
                return 1;
        }
        if (*str == '=')
                str++;
        for (s = str; s && *s != '\0'; s = curend) {
                cur = s;
                /* ignore empties.  Don't treat as "all-on" or "all-off" */
                while (*cur == ',')
                        cur++;
                curend = strchr(cur, ',');
                if (!curend)
                        curend = cur + strlen(cur);
                if (*cur) {
                        int curlen = curend-cur;
                        if (eeh_opts_last + curlen > EEH_MAX_OPTS-2) {
                                printk(KERN_WARNING "EEH: sorry...too many "
                                       "eeh cmd line options\n");
                                return 1;
                        }
                        eeh_opts[eeh_opts_last++] = state ? '+' : '-';
                        strncpy(eeh_opts+eeh_opts_last, cur, curlen);
                        eeh_opts_last += curlen;
                        eeh_opts[eeh_opts_last++] = '\0';
                }
        }

        return 1;
}

static int __init eehoff_parm(char *str)
{
        return eeh_parm(str, 0);
}

static int __init eehon_parm(char *str)
{
        return eeh_parm(str, 1);
}

__setup("eeh-off", eehoff_parm);
__setup("eeh-on", eehon_parm);