osl.c

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/*
 *  acpi_osl.c - OS-dependent functions ($Revision: 83 $)
 *
 *  Copyright (C) 2000       Andrew Henroid
 *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
 *  Copyright (c) 2008 Intel Corporation
 *   Author: Matthew Wilcox <[email protected]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/nmi.h>
#include <linux/acpi.h>
#include <linux/acpi_io.h>
#include <linux/efi.h>
#include <linux/ioport.h>
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/semaphore.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/processor.h>

#define _COMPONENT      ACPI_OS_SERVICES
ACPI_MODULE_NAME("osl");
#define PREFIX      "ACPI: "
struct acpi_os_dpc {
    acpi_osd_exec_callback function;
    void *context;
    struct work_struct work;
    int wait;
};

#ifdef CONFIG_ACPI_CUSTOM_DSDT
#include CONFIG_ACPI_CUSTOM_DSDT_FILE
#endif

#ifdef ENABLE_DEBUGGER
#include <linux/kdb.h>

/* stuff for debugger support */
int acpi_in_debugger;
EXPORT_SYMBOL(acpi_in_debugger);

extern char line_buf[80];
#endif              /*ENABLE_DEBUGGER */

static int (*__acpi_os_prepare_sleep)(u8 sleep_state, u32 pm1a_ctrl,
                      u32 pm1b_ctrl);

static acpi_osd_handler acpi_irq_handler;
static void *acpi_irq_context;
static struct workqueue_struct *kacpid_wq;
static struct workqueue_struct *kacpi_notify_wq;
struct workqueue_struct *kacpi_hotplug_wq;
EXPORT_SYMBOL(kacpi_hotplug_wq);

/*
 * This list of permanent mappings is for memory that may be accessed from
 * interrupt context, where we can't do the ioremap().
 */
struct acpi_ioremap {
    struct list_head list;
    void __iomem *virt;
    acpi_physical_address phys;
    acpi_size size;
    unsigned long refcount;
};

static LIST_HEAD(acpi_ioremaps);
static DEFINE_MUTEX(acpi_ioremap_lock);

static void __init acpi_osi_setup_late(void);

/*
 * The story of _OSI(Linux)
 *
 * From pre-history through Linux-2.6.22,
 * Linux responded TRUE upon a BIOS OSI(Linux) query.
 *
 * Unfortunately, reference BIOS writers got wind of this
 * and put OSI(Linux) in their example code, quickly exposing
 * this string as ill-conceived and opening the door to
 * an un-bounded number of BIOS incompatibilities.
 *
 * For example, OSI(Linux) was used on resume to re-POST a
 * video card on one system, because Linux at that time
 * could not do a speedy restore in its native driver.
 * But then upon gaining quick native restore capability,
 * Linux has no way to tell the BIOS to skip the time-consuming
 * POST -- putting Linux at a permanent performance disadvantage.
 * On another system, the BIOS writer used OSI(Linux)
 * to infer native OS support for IPMI!  On other systems,
 * OSI(Linux) simply got in the way of Linux claiming to
 * be compatible with other operating systems, exposing
 * BIOS issues such as skipped device initialization.
 *
 * So "Linux" turned out to be a really poor chose of
 * OSI string, and from Linux-2.6.23 onward we respond FALSE.
 *
 * BIOS writers should NOT query _OSI(Linux) on future systems.
 * Linux will complain on the console when it sees it, and return FALSE.
 * To get Linux to return TRUE for your system  will require
 * a kernel source update to add a DMI entry,
 * or boot with "acpi_osi=Linux"
 */

static struct osi_linux {
    unsigned int    enable:1;
    unsigned int    dmi:1;
    unsigned int    cmdline:1;
} osi_linux = {0, 0, 0};

static u32 acpi_osi_handler(acpi_string interface, u32 supported)
{
    if (!strcmp("Linux", interface)) {

        printk_once(KERN_NOTICE FW_BUG PREFIX
            "BIOS _OSI(Linux) query %s%s\n",
            osi_linux.enable ? "honored" : "ignored",
            osi_linux.cmdline ? " via cmdline" :
            osi_linux.dmi ? " via DMI" : "");
    }

    return supported;
}

static void __init acpi_request_region (struct acpi_generic_address *gas,
    unsigned int length, char *desc)
{
    u64 addr;

    /* Handle possible alignment issues */
    memcpy(&addr, &gas->address, sizeof(addr));
    if (!addr || !length)
        return;

    /* Resources are never freed */
    if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO)
        request_region(addr, length, desc);
    else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
        request_mem_region(addr, length, desc);
}

static int __init acpi_reserve_resources(void)
{
    acpi_request_region(&acpi_gbl_FADT.xpm1a_event_block, acpi_gbl_FADT.pm1_event_length,
        "ACPI PM1a_EVT_BLK");

    acpi_request_region(&acpi_gbl_FADT.xpm1b_event_block, acpi_gbl_FADT.pm1_event_length,
        "ACPI PM1b_EVT_BLK");

    acpi_request_region(&acpi_gbl_FADT.xpm1a_control_block, acpi_gbl_FADT.pm1_control_length,
        "ACPI PM1a_CNT_BLK");

    acpi_request_region(&acpi_gbl_FADT.xpm1b_control_block, acpi_gbl_FADT.pm1_control_length,
        "ACPI PM1b_CNT_BLK");

    if (acpi_gbl_FADT.pm_timer_length == 4)
        acpi_request_region(&acpi_gbl_FADT.xpm_timer_block, 4, "ACPI PM_TMR");

    acpi_request_region(&acpi_gbl_FADT.xpm2_control_block, acpi_gbl_FADT.pm2_control_length,
        "ACPI PM2_CNT_BLK");

    /* Length of GPE blocks must be a non-negative multiple of 2 */

    if (!(acpi_gbl_FADT.gpe0_block_length & 0x1))
        acpi_request_region(&acpi_gbl_FADT.xgpe0_block,
                   acpi_gbl_FADT.gpe0_block_length, "ACPI GPE0_BLK");

    if (!(acpi_gbl_FADT.gpe1_block_length & 0x1))
        acpi_request_region(&acpi_gbl_FADT.xgpe1_block,
                   acpi_gbl_FADT.gpe1_block_length, "ACPI GPE1_BLK");

    return 0;
}
device_initcall(acpi_reserve_resources);

void acpi_os_printf(const char *fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    acpi_os_vprintf(fmt, args);
    va_end(args);
}

void acpi_os_vprintf(const char *fmt, va_list args)
{
    static char buffer[512];

    vsprintf(buffer, fmt, args);

#ifdef ENABLE_DEBUGGER
    if (acpi_in_debugger) {
        kdb_printf("%s", buffer);
    } else {
        printk(KERN_CONT "%s", buffer);
    }
#else
    printk(KERN_CONT "%s", buffer);
#endif
}

#ifdef CONFIG_KEXEC
static unsigned long acpi_rsdp;
static int __init setup_acpi_rsdp(char *arg)
{
    acpi_rsdp = simple_strtoul(arg, NULL, 16);
    return 0;
}
early_param("acpi_rsdp", setup_acpi_rsdp);
#endif

acpi_physical_address __init acpi_os_get_root_pointer(void)
{
#ifdef CONFIG_KEXEC
    if (acpi_rsdp)
        return acpi_rsdp;
#endif

    if (efi_enabled) {
        if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
            return efi.acpi20;
        else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
            return efi.acpi;
        else {
            printk(KERN_ERR PREFIX
                   "System description tables not found\n");
            return 0;
        }
    } else {
        acpi_physical_address pa = 0;

        acpi_find_root_pointer(&pa);
        return pa;
    }
}

/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
static struct acpi_ioremap *
acpi_map_lookup(acpi_physical_address phys, acpi_size size)
{
    struct acpi_ioremap *map;

    list_for_each_entry_rcu(map, &acpi_ioremaps, list)
        if (map->phys <= phys &&
            phys + size <= map->phys + map->size)
            return map;

    return NULL;
}

/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
static void __iomem *
acpi_map_vaddr_lookup(acpi_physical_address phys, unsigned int size)
{
    struct acpi_ioremap *map;

    map = acpi_map_lookup(phys, size);
    if (map)
        return map->virt + (phys - map->phys);

    return NULL;
}

void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size)
{
    struct acpi_ioremap *map;
    void __iomem *virt = NULL;

    mutex_lock(&acpi_ioremap_lock);
    map = acpi_map_lookup(phys, size);
    if (map) {
        virt = map->virt + (phys - map->phys);
        map->refcount++;
    }
    mutex_unlock(&acpi_ioremap_lock);
    return virt;
}
EXPORT_SYMBOL_GPL(acpi_os_get_iomem);

/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
static struct acpi_ioremap *
acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
{
    struct acpi_ioremap *map;

    list_for_each_entry_rcu(map, &acpi_ioremaps, list)
        if (map->virt <= virt &&
            virt + size <= map->virt + map->size)
            return map;

    return NULL;
}

#ifndef CONFIG_IA64
#define should_use_kmap(pfn)   page_is_ram(pfn)
#else
/* ioremap will take care of cache attributes */
#define should_use_kmap(pfn)   0
#endif

static void __iomem *acpi_map(acpi_physical_address pg_off, unsigned long pg_sz)
{
    unsigned long pfn;

    pfn = pg_off >> PAGE_SHIFT;
    if (should_use_kmap(pfn)) {
        if (pg_sz > PAGE_SIZE)
            return NULL;
        return (void __iomem __force *)kmap(pfn_to_page(pfn));
    } else
        return acpi_os_ioremap(pg_off, pg_sz);
}

static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
{
    unsigned long pfn;

    pfn = pg_off >> PAGE_SHIFT;
    if (should_use_kmap(pfn))
        kunmap(pfn_to_page(pfn));
    else
        iounmap(vaddr);
}

void __iomem *__init_refok
acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
    struct acpi_ioremap *map;
    void __iomem *virt;
    acpi_physical_address pg_off;
    acpi_size pg_sz;

    if (phys > ULONG_MAX) {
        printk(KERN_ERR PREFIX "Cannot map memory that high\n");
        return NULL;
    }

    if (!acpi_gbl_permanent_mmap)
        return __acpi_map_table((unsigned long)phys, size);

    mutex_lock(&acpi_ioremap_lock);
    /* Check if there's a suitable mapping already. */
    map = acpi_map_lookup(phys, size);
    if (map) {
        map->refcount++;
        goto out;
    }

    map = kzalloc(sizeof(*map), GFP_KERNEL);
    if (!map) {
        mutex_unlock(&acpi_ioremap_lock);
        return NULL;
    }

    pg_off = round_down(phys, PAGE_SIZE);
    pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off;
    virt = acpi_map(pg_off, pg_sz);
    if (!virt) {
        mutex_unlock(&acpi_ioremap_lock);
        kfree(map);
        return NULL;
    }

    INIT_LIST_HEAD(&map->list);
    map->virt = virt;
    map->phys = pg_off;
    map->size = pg_sz;
    map->refcount = 1;

    list_add_tail_rcu(&map->list, &acpi_ioremaps);

 out:
    mutex_unlock(&acpi_ioremap_lock);
    return map->virt + (phys - map->phys);
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);

static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
{
    if (!--map->refcount)
        list_del_rcu(&map->list);
}

static void acpi_os_map_cleanup(struct acpi_ioremap *map)
{
    if (!map->refcount) {
        synchronize_rcu();
        acpi_unmap(map->phys, map->virt);
        kfree(map);
    }
}

void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{
    struct acpi_ioremap *map;

    if (!acpi_gbl_permanent_mmap) {
        __acpi_unmap_table(virt, size);
        return;
    }

    mutex_lock(&acpi_ioremap_lock);
    map = acpi_map_lookup_virt(virt, size);
    if (!map) {
        mutex_unlock(&acpi_ioremap_lock);
        WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
        return;
    }
    acpi_os_drop_map_ref(map);
    mutex_unlock(&acpi_ioremap_lock);

    acpi_os_map_cleanup(map);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);

void __init early_acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{
    if (!acpi_gbl_permanent_mmap)
        __acpi_unmap_table(virt, size);
}

int acpi_os_map_generic_address(struct acpi_generic_address *gas)
{
    u64 addr;
    void __iomem *virt;

    if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
        return 0;

    /* Handle possible alignment issues */
    memcpy(&addr, &gas->address, sizeof(addr));
    if (!addr || !gas->bit_width)
        return -EINVAL;

    virt = acpi_os_map_memory(addr, gas->bit_width / 8);
    if (!virt)
        return -EIO;

    return 0;
}
EXPORT_SYMBOL(acpi_os_map_generic_address);

void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
{
    u64 addr;
    struct acpi_ioremap *map;

    if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
        return;

    /* Handle possible alignment issues */
    memcpy(&addr, &gas->address, sizeof(addr));
    if (!addr || !gas->bit_width)
        return;

    mutex_lock(&acpi_ioremap_lock);
    map = acpi_map_lookup(addr, gas->bit_width / 8);
    if (!map) {
        mutex_unlock(&acpi_ioremap_lock);
        return;
    }
    acpi_os_drop_map_ref(map);
    mutex_unlock(&acpi_ioremap_lock);

    acpi_os_map_cleanup(map);
}
EXPORT_SYMBOL(acpi_os_unmap_generic_address);

#ifdef ACPI_FUTURE_USAGE
acpi_status
acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
{
    if (!phys || !virt)
        return AE_BAD_PARAMETER;

    *phys = virt_to_phys(virt);

    return AE_OK;
}
#endif

#define ACPI_MAX_OVERRIDE_LEN 100

static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];

acpi_status
acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
                acpi_string * new_val)
{
    if (!init_val || !new_val)
        return AE_BAD_PARAMETER;

    *new_val = NULL;
    if (!memcmp(init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
        printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
               acpi_os_name);
        *new_val = acpi_os_name;
    }

    return AE_OK;
}

acpi_status
acpi_os_table_override(struct acpi_table_header * existing_table,
               struct acpi_table_header ** new_table)
{
    if (!existing_table || !new_table)
        return AE_BAD_PARAMETER;

    *new_table = NULL;

#ifdef CONFIG_ACPI_CUSTOM_DSDT
    if (strncmp(existing_table->signature, "DSDT", 4) == 0)
        *new_table = (struct acpi_table_header *)AmlCode;
#endif
    if (*new_table != NULL) {
        printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
               "this is unsafe: tainting kernel\n",
               existing_table->signature,
               existing_table->oem_table_id);
        add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
    }
    return AE_OK;
}

acpi_status
acpi_os_physical_table_override(struct acpi_table_header *existing_table,
                acpi_physical_address * new_address,
                u32 *new_table_length)
{
    return AE_SUPPORT;
}


static irqreturn_t acpi_irq(int irq, void *dev_id)
{
    u32 handled;

    handled = (*acpi_irq_handler) (acpi_irq_context);

    if (handled) {
        acpi_irq_handled++;
        return IRQ_HANDLED;
    } else {
        acpi_irq_not_handled++;
        return IRQ_NONE;
    }
}

acpi_status
acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
                  void *context)
{
    unsigned int irq;

    acpi_irq_stats_init();

    /*
     * ACPI interrupts different from the SCI in our copy of the FADT are
     * not supported.
     */
    if (gsi != acpi_gbl_FADT.sci_interrupt)
        return AE_BAD_PARAMETER;

    if (acpi_irq_handler)
        return AE_ALREADY_ACQUIRED;

    if (acpi_gsi_to_irq(gsi, &irq) < 0) {
        printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
               gsi);
        return AE_OK;
    }

    acpi_irq_handler = handler;
    acpi_irq_context = context;
    if (request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq)) {
        printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
        acpi_irq_handler = NULL;
        return AE_NOT_ACQUIRED;
    }

    return AE_OK;
}

acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
{
    if (irq != acpi_gbl_FADT.sci_interrupt)
        return AE_BAD_PARAMETER;

    free_irq(irq, acpi_irq);
    acpi_irq_handler = NULL;

    return AE_OK;
}

/*
 * Running in interpreter thread context, safe to sleep
 */

void acpi_os_sleep(u64 ms)
{
    schedule_timeout_interruptible(msecs_to_jiffies(ms));
}

void acpi_os_stall(u32 us)
{
    while (us) {
        u32 delay = 1000;

        if (delay > us)
            delay = us;
        udelay(delay);
        touch_nmi_watchdog();
        us -= delay;
    }
}

/*
 * Support ACPI 3.0 AML Timer operand
 * Returns 64-bit free-running, monotonically increasing timer
 * with 100ns granularity
 */
u64 acpi_os_get_timer(void)
{
    static u64 t;

#ifdef  CONFIG_HPET
    /* TBD: use HPET if available */
#endif

#ifdef  CONFIG_X86_PM_TIMER
    /* TBD: default to PM timer if HPET was not available */
#endif
    if (!t)
        printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");

    return ++t;
}

acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
{
    u32 dummy;

    if (!value)
        value = &dummy;

    *value = 0;
    if (width <= 8) {
        *(u8 *) value = inb(port);
    } else if (width <= 16) {
        *(u16 *) value = inw(port);
    } else if (width <= 32) {
        *(u32 *) value = inl(port);
    } else {
        BUG();
    }

    return AE_OK;
}

EXPORT_SYMBOL(acpi_os_read_port);

acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width)
{
    if (width <= 8) {
        outb(value, port);
    } else if (width <= 16) {
        outw(value, port);
    } else if (width <= 32) {
        outl(value, port);
    } else {
        BUG();
    }

    return AE_OK;
}

EXPORT_SYMBOL(acpi_os_write_port);

#ifdef readq
static inline u64 read64(const volatile void __iomem *addr)
{
    return readq(addr);
}
#else
static inline u64 read64(const volatile void __iomem *addr)
{
    u64 l, h;
    l = readl(addr);
    h = readl(addr+4);
    return l | (h << 32);
}
#endif

acpi_status
acpi_os_read_memory(acpi_physical_address phys_addr, u64 *value, u32 width)
{
    void __iomem *virt_addr;
    unsigned int size = width / 8;
    bool unmap = false;
    u64 dummy;

    rcu_read_lock();
    virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
    if (!virt_addr) {
        rcu_read_unlock();
        virt_addr = acpi_os_ioremap(phys_addr, size);
        if (!virt_addr)
            return AE_BAD_ADDRESS;
        unmap = true;
    }

    if (!value)
        value = &dummy;

    switch (width) {
    case 8:
        *(u8 *) value = readb(virt_addr);
        break;
    case 16:
        *(u16 *) value = readw(virt_addr);
        break;
    case 32:
        *(u32 *) value = readl(virt_addr);
        break;
    case 64:
        *(u64 *) value = read64(virt_addr);
        break;
    default:
        BUG();
    }

    if (unmap)
        iounmap(virt_addr);
    else
        rcu_read_unlock();

    return AE_OK;
}

#ifdef writeq
static inline void write64(u64 val, volatile void __iomem *addr)
{
    writeq(val, addr);
}
#else
static inline void write64(u64 val, volatile void __iomem *addr)
{
    writel(val, addr);
    writel(val>>32, addr+4);
}
#endif

acpi_status
acpi_os_write_memory(acpi_physical_address phys_addr, u64 value, u32 width)
{
    void __iomem *virt_addr;
    unsigned int size = width / 8;
    bool unmap = false;

    rcu_read_lock();
    virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
    if (!virt_addr) {
        rcu_read_unlock();
        virt_addr = acpi_os_ioremap(phys_addr, size);
        if (!virt_addr)
            return AE_BAD_ADDRESS;
        unmap = true;
    }

    switch (width) {
    case 8:
        writeb(value, virt_addr);
        break;
    case 16:
        writew(value, virt_addr);
        break;
    case 32:
        writel(value, virt_addr);
        break;
    case 64:
        write64(value, virt_addr);
        break;
    default:
        BUG();
    }

    if (unmap)
        iounmap(virt_addr);
    else
        rcu_read_unlock();

    return AE_OK;
}

acpi_status
acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
                   u64 *value, u32 width)
{
    int result, size;
    u32 value32;

    if (!value)
        return AE_BAD_PARAMETER;

    switch (width) {
    case 8:
        size = 1;
        break;
    case 16:
        size = 2;
        break;
    case 32:
        size = 4;
        break;
    default:
        return AE_ERROR;
    }

    result = raw_pci_read(pci_id->segment, pci_id->bus,
                PCI_DEVFN(pci_id->device, pci_id->function),
                reg, size, &value32);
    *value = value32;

    return (result ? AE_ERROR : AE_OK);
}

acpi_status
acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
                u64 value, u32 width)
{
    int result, size;

    switch (width) {
    case 8:
        size = 1;
        break;
    case 16:
        size = 2;
        break;
    case 32:
        size = 4;
        break;
    default:
        return AE_ERROR;
    }

    result = raw_pci_write(pci_id->segment, pci_id->bus,
                PCI_DEVFN(pci_id->device, pci_id->function),
                reg, size, value);

    return (result ? AE_ERROR : AE_OK);
}

static void acpi_os_execute_deferred(struct work_struct *work)
{
    struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work);

    if (dpc->wait)
        acpi_os_wait_events_complete();

    dpc->function(dpc->context);
    kfree(dpc);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_execute
 *
 * PARAMETERS:  Type               - Type of the callback
 *              Function           - Function to be executed
 *              Context            - Function parameters
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Depending on type, either queues function for deferred execution or
 *              immediately executes function on a separate thread.
 *
 ******************************************************************************/

static acpi_status __acpi_os_execute(acpi_execute_type type,
    acpi_osd_exec_callback function, void *context, int hp)
{
    acpi_status status = AE_OK;
    struct acpi_os_dpc *dpc;
    struct workqueue_struct *queue;
    int ret;
    ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
              "Scheduling function [%p(%p)] for deferred execution.\n",
              function, context));

    /*
     * Allocate/initialize DPC structure.  Note that this memory will be
     * freed by the callee.  The kernel handles the work_struct list  in a
     * way that allows us to also free its memory inside the callee.
     * Because we may want to schedule several tasks with different
     * parameters we can't use the approach some kernel code uses of
     * having a static work_struct.
     */

    dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC);
    if (!dpc)
        return AE_NO_MEMORY;

    dpc->function = function;
    dpc->context = context;

    /*
     * We can't run hotplug code in keventd_wq/kacpid_wq/kacpid_notify_wq
     * because the hotplug code may call driver .remove() functions,
     * which invoke flush_scheduled_work/acpi_os_wait_events_complete
     * to flush these workqueues.
     */
    queue = hp ? kacpi_hotplug_wq :
        (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq);
    dpc->wait = hp ? 1 : 0;

    if (queue == kacpi_hotplug_wq)
        INIT_WORK(&dpc->work, acpi_os_execute_deferred);
    else if (queue == kacpi_notify_wq)
        INIT_WORK(&dpc->work, acpi_os_execute_deferred);
    else
        INIT_WORK(&dpc->work, acpi_os_execute_deferred);

    /*
     * On some machines, a software-initiated SMI causes corruption unless
     * the SMI runs on CPU 0.  An SMI can be initiated by any AML, but
     * typically it's done in GPE-related methods that are run via
     * workqueues, so we can avoid the known corruption cases by always
     * queueing on CPU 0.
     */
    ret = queue_work_on(0, queue, &dpc->work);

    if (!ret) {
        printk(KERN_ERR PREFIX
              "Call to queue_work() failed.\n");
        status = AE_ERROR;
        kfree(dpc);
    }
    return status;
}

acpi_status acpi_os_execute(acpi_execute_type type,
                acpi_osd_exec_callback function, void *context)
{
    return __acpi_os_execute(type, function, context, 0);
}
EXPORT_SYMBOL(acpi_os_execute);

acpi_status acpi_os_hotplug_execute(acpi_osd_exec_callback function,
    void *context)
{
    return __acpi_os_execute(0, function, context, 1);
}

void acpi_os_wait_events_complete(void)
{
    flush_workqueue(kacpid_wq);
    flush_workqueue(kacpi_notify_wq);
}

EXPORT_SYMBOL(acpi_os_wait_events_complete);

acpi_status
acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
{
    struct semaphore *sem = NULL;

    sem = acpi_os_allocate(sizeof(struct semaphore));
    if (!sem)
        return AE_NO_MEMORY;
    memset(sem, 0, sizeof(struct semaphore));

    sema_init(sem, initial_units);

    *handle = (acpi_handle *) sem;

    ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n",
              *handle, initial_units));

    return AE_OK;
}

/*
 * TODO: A better way to delete semaphores?  Linux doesn't have a
 * 'delete_semaphore()' function -- may result in an invalid
 * pointer dereference for non-synchronized consumers.  Should
 * we at least check for blocked threads and signal/cancel them?
 */

acpi_status acpi_os_delete_semaphore(acpi_handle handle)
{
    struct semaphore *sem = (struct semaphore *)handle;

    if (!sem)
        return AE_BAD_PARAMETER;

    ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));

    BUG_ON(!list_empty(&sem->wait_list));
    kfree(sem);
    sem = NULL;

    return AE_OK;
}

/*
 * TODO: Support for units > 1?
 */
acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
{
    acpi_status status = AE_OK;
    struct semaphore *sem = (struct semaphore *)handle;
    long jiffies;
    int ret = 0;

    if (!sem || (units < 1))
        return AE_BAD_PARAMETER;

    if (units > 1)
        return AE_SUPPORT;

    ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
              handle, units, timeout));

    if (timeout == ACPI_WAIT_FOREVER)
        jiffies = MAX_SCHEDULE_TIMEOUT;
    else
        jiffies = msecs_to_jiffies(timeout);
    
    ret = down_timeout(sem, jiffies);
    if (ret)
        status = AE_TIME;

    if (ACPI_FAILURE(status)) {
        ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
                  "Failed to acquire semaphore[%p|%d|%d], %s",
                  handle, units, timeout,
                  acpi_format_exception(status)));
    } else {
        ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
                  "Acquired semaphore[%p|%d|%d]", handle,
                  units, timeout));
    }

    return status;
}

/*
 * TODO: Support for units > 1?
 */
acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
{
    struct semaphore *sem = (struct semaphore *)handle;

    if (!sem || (units < 1))
        return AE_BAD_PARAMETER;

    if (units > 1)
        return AE_SUPPORT;

    ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle,
              units));

    up(sem);

    return AE_OK;
}

#ifdef ACPI_FUTURE_USAGE
u32 acpi_os_get_line(char *buffer)
{

#ifdef ENABLE_DEBUGGER
    if (acpi_in_debugger) {
        u32 chars;

        kdb_read(buffer, sizeof(line_buf));

        /* remove the CR kdb includes */
        chars = strlen(buffer) - 1;
        buffer[chars] = '\0';
    }
#endif

    return 0;
}
#endif              /*  ACPI_FUTURE_USAGE  */

acpi_status acpi_os_signal(u32 function, void *info)
{
    switch (function) {
    case ACPI_SIGNAL_FATAL:
        printk(KERN_ERR PREFIX "Fatal opcode executed\n");
        break;
    case ACPI_SIGNAL_BREAKPOINT:
        /*
         * AML Breakpoint
         * ACPI spec. says to treat it as a NOP unless
         * you are debugging.  So if/when we integrate
         * AML debugger into the kernel debugger its
         * hook will go here.  But until then it is
         * not useful to print anything on breakpoints.
         */
        break;
    default:
        break;
    }

    return AE_OK;
}

static int __init acpi_os_name_setup(char *str)
{
    char *p = acpi_os_name;
    int count = ACPI_MAX_OVERRIDE_LEN - 1;

    if (!str || !*str)
        return 0;

    for (; count-- && str && *str; str++) {
        if (isalnum(*str) || *str == ' ' || *str == ':')
            *p++ = *str;
        else if (*str == '\'' || *str == '"')
            continue;
        else
            break;
    }
    *p = 0;

    return 1;

}

__setup("acpi_os_name=", acpi_os_name_setup);

#define OSI_STRING_LENGTH_MAX 64    /* arbitrary */
#define OSI_STRING_ENTRIES_MAX 16   /* arbitrary */

struct osi_setup_entry {
    char string[OSI_STRING_LENGTH_MAX];
    bool enable;
};

static struct osi_setup_entry __initdata
        osi_setup_entries[OSI_STRING_ENTRIES_MAX] = {
    {"Module Device", true},
    {"Processor Device", true},
    {"3.0 _SCP Extensions", true},
    {"Processor Aggregator Device", true},
};

void __init acpi_osi_setup(char *str)
{
    struct osi_setup_entry *osi;
    bool enable = true;
    int i;

    if (!acpi_gbl_create_osi_method)
        return;

    if (str == NULL || *str == '\0') {
        printk(KERN_INFO PREFIX "_OSI method disabled\n");
        acpi_gbl_create_osi_method = FALSE;
        return;
    }

    if (*str == '!') {
        str++;
        enable = false;
    }

    for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
        osi = &osi_setup_entries[i];
        if (!strcmp(osi->string, str)) {
            osi->enable = enable;
            break;
        } else if (osi->string[0] == '\0') {
            osi->enable = enable;
            strncpy(osi->string, str, OSI_STRING_LENGTH_MAX);
            break;
        }
    }
}

static void __init set_osi_linux(unsigned int enable)
{
    if (osi_linux.enable != enable)
        osi_linux.enable = enable;

    if (osi_linux.enable)
        acpi_osi_setup("Linux");
    else
        acpi_osi_setup("!Linux");

    return;
}

static void __init acpi_cmdline_osi_linux(unsigned int enable)
{
    osi_linux.cmdline = 1;  /* cmdline set the default and override DMI */
    osi_linux.dmi = 0;
    set_osi_linux(enable);

    return;
}

void __init acpi_dmi_osi_linux(int enable, const struct dmi_system_id *d)
{
    printk(KERN_NOTICE PREFIX "DMI detected: %s\n", d->ident);

    if (enable == -1)
        return;

    osi_linux.dmi = 1;  /* DMI knows that this box asks OSI(Linux) */
    set_osi_linux(enable);

    return;
}

/*
 * Modify the list of "OS Interfaces" reported to BIOS via _OSI
 *
 * empty string disables _OSI
 * string starting with '!' disables that string
 * otherwise string is added to list, augmenting built-in strings
 */
static void __init acpi_osi_setup_late(void)
{
    struct osi_setup_entry *osi;
    char *str;
    int i;
    acpi_status status;

    for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
        osi = &osi_setup_entries[i];
        str = osi->string;

        if (*str == '\0')
            break;
        if (osi->enable) {
            status = acpi_install_interface(str);

            if (ACPI_SUCCESS(status))
                printk(KERN_INFO PREFIX "Added _OSI(%s)\n", str);
        } else {
            status = acpi_remove_interface(str);

            if (ACPI_SUCCESS(status))
                printk(KERN_INFO PREFIX "Deleted _OSI(%s)\n", str);
        }
    }
}

static int __init osi_setup(char *str)
{
    if (str && !strcmp("Linux", str))
        acpi_cmdline_osi_linux(1);
    else if (str && !strcmp("!Linux", str))
        acpi_cmdline_osi_linux(0);
    else
        acpi_osi_setup(str);

    return 1;
}

__setup("acpi_osi=", osi_setup);

/* enable serialization to combat AE_ALREADY_EXISTS errors */
static int __init acpi_serialize_setup(char *str)
{
    printk(KERN_INFO PREFIX "serialize enabled\n");

    acpi_gbl_all_methods_serialized = TRUE;

    return 1;
}

__setup("acpi_serialize", acpi_serialize_setup);

/* Check of resource interference between native drivers and ACPI
 * OperationRegions (SystemIO and System Memory only).
 * IO ports and memory declared in ACPI might be used by the ACPI subsystem
 * in arbitrary AML code and can interfere with legacy drivers.
 * acpi_enforce_resources= can be set to:
 *
 *   - strict (default) (2)
 *     -> further driver trying to access the resources will not load
 *   - lax              (1)
 *     -> further driver trying to access the resources will load, but you
 *     get a system message that something might go wrong...
 *
 *   - no               (0)
 *     -> ACPI Operation Region resources will not be registered
 *
 */
#define ENFORCE_RESOURCES_STRICT 2
#define ENFORCE_RESOURCES_LAX    1
#define ENFORCE_RESOURCES_NO     0

static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;

static int __init acpi_enforce_resources_setup(char *str)
{
    if (str == NULL || *str == '\0')
        return 0;

    if (!strcmp("strict", str))
        acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
    else if (!strcmp("lax", str))
        acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
    else if (!strcmp("no", str))
        acpi_enforce_resources = ENFORCE_RESOURCES_NO;

    return 1;
}

__setup("acpi_enforce_resources=", acpi_enforce_resources_setup);

/* Check for resource conflicts between ACPI OperationRegions and native
 * drivers */
int acpi_check_resource_conflict(const struct resource *res)
{
    acpi_adr_space_type space_id;
    acpi_size length;
    u8 warn = 0;
    int clash = 0;

    if (acpi_enforce_resources == ENFORCE_RESOURCES_NO)
        return 0;
    if (!(res->flags & IORESOURCE_IO) && !(res->flags & IORESOURCE_MEM))
        return 0;

    if (res->flags & IORESOURCE_IO)
        space_id = ACPI_ADR_SPACE_SYSTEM_IO;
    else
        space_id = ACPI_ADR_SPACE_SYSTEM_MEMORY;

    length = res->end - res->start + 1;
    if (acpi_enforce_resources != ENFORCE_RESOURCES_NO)
        warn = 1;
    clash = acpi_check_address_range(space_id, res->start, length, warn);

    if (clash) {
        if (acpi_enforce_resources != ENFORCE_RESOURCES_NO) {
            if (acpi_enforce_resources == ENFORCE_RESOURCES_LAX)
                printk(KERN_NOTICE "ACPI: This conflict may"
                       " cause random problems and system"
                       " instability\n");
            printk(KERN_INFO "ACPI: If an ACPI driver is available"
                   " for this device, you should use it instead of"
                   " the native driver\n");
        }
        if (acpi_enforce_resources == ENFORCE_RESOURCES_STRICT)
            return -EBUSY;
    }
    return 0;
}
EXPORT_SYMBOL(acpi_check_resource_conflict);

int acpi_check_region(resource_size_t start, resource_size_t n,
              const char *name)
{
    struct resource res = {
        .start = start,
        .end   = start + n - 1,
        .name  = name,
        .flags = IORESOURCE_IO,
    };

    return acpi_check_resource_conflict(&res);
}
EXPORT_SYMBOL(acpi_check_region);

/*
 * Let drivers know whether the resource checks are effective
 */
int acpi_resources_are_enforced(void)
{
    return acpi_enforce_resources == ENFORCE_RESOURCES_STRICT;
}
EXPORT_SYMBOL(acpi_resources_are_enforced);

/*
 * Deallocate the memory for a spinlock.
 */
void acpi_os_delete_lock(acpi_spinlock handle)
{
    ACPI_FREE(handle);
}

/*
 * Acquire a spinlock.
 *
 * handle is a pointer to the spinlock_t.
 */

acpi_cpu_flags acpi_os_acquire_lock(acpi_spinlock lockp)
{
    acpi_cpu_flags flags;
    spin_lock_irqsave(lockp, flags);
    return flags;
}

/*
 * Release a spinlock. See above.
 */

void acpi_os_release_lock(acpi_spinlock lockp, acpi_cpu_flags flags)
{
    spin_unlock_irqrestore(lockp, flags);
}

#ifndef ACPI_USE_LOCAL_CACHE

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_create_cache
 *
 * PARAMETERS:  name      - Ascii name for the cache
 *              size      - Size of each cached object
 *              depth     - Maximum depth of the cache (in objects) <ignored>
 *              cache     - Where the new cache object is returned
 *
 * RETURN:      status
 *
 * DESCRIPTION: Create a cache object
 *
 ******************************************************************************/

acpi_status
acpi_os_create_cache(char *name, u16 size, u16 depth, acpi_cache_t ** cache)
{
    *cache = kmem_cache_create(name, size, 0, 0, NULL);
    if (*cache == NULL)
        return AE_ERROR;
    else
        return AE_OK;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_purge_cache
 *
 * PARAMETERS:  Cache           - Handle to cache object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Free all objects within the requested cache.
 *
 ******************************************************************************/

acpi_status acpi_os_purge_cache(acpi_cache_t * cache)
{
    kmem_cache_shrink(cache);
    return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_delete_cache
 *
 * PARAMETERS:  Cache           - Handle to cache object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Free all objects within the requested cache and delete the
 *              cache object.
 *
 ******************************************************************************/

acpi_status acpi_os_delete_cache(acpi_cache_t * cache)
{
    kmem_cache_destroy(cache);
    return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_release_object
 *
 * PARAMETERS:  Cache       - Handle to cache object
 *              Object      - The object to be released
 *
 * RETURN:      None
 *
 * DESCRIPTION: Release an object to the specified cache.  If cache is full,
 *              the object is deleted.
 *
 ******************************************************************************/

acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
{
    kmem_cache_free(cache, object);
    return (AE_OK);
}
#endif

acpi_status __init acpi_os_initialize(void)
{
    acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block);
    acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
    acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block);
    acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block);

    return AE_OK;
}

acpi_status __init acpi_os_initialize1(void)
{
    kacpid_wq = alloc_workqueue("kacpid", 0, 1);
    kacpi_notify_wq = alloc_workqueue("kacpi_notify", 0, 1);
    kacpi_hotplug_wq = alloc_workqueue("kacpi_hotplug", 0, 1);
    BUG_ON(!kacpid_wq);
    BUG_ON(!kacpi_notify_wq);
    BUG_ON(!kacpi_hotplug_wq);
    acpi_install_interface_handler(acpi_osi_handler);
    acpi_osi_setup_late();
    return AE_OK;
}

acpi_status acpi_os_terminate(void)
{
    if (acpi_irq_handler) {
        acpi_os_remove_interrupt_handler(acpi_gbl_FADT.sci_interrupt,
                         acpi_irq_handler);
    }

    acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block);
    acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block);
    acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
    acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block);

    destroy_workqueue(kacpid_wq);
    destroy_workqueue(kacpi_notify_wq);
    destroy_workqueue(kacpi_hotplug_wq);

    return AE_OK;
}

acpi_status acpi_os_prepare_sleep(u8 sleep_state, u32 pm1a_control,
                  u32 pm1b_control)
{
    int rc = 0;
    if (__acpi_os_prepare_sleep)
        rc = __acpi_os_prepare_sleep(sleep_state,
                         pm1a_control, pm1b_control);
    if (rc < 0)
        return AE_ERROR;
    else if (rc > 0)
        return AE_CTRL_SKIP;

    return AE_OK;
}

void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
                   u32 pm1a_ctrl, u32 pm1b_ctrl))
{
    __acpi_os_prepare_sleep = func;
}