ACPI: Fix acpi_os_read_memory() and acpi_os_write_memory() (v2)

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / acpi / osl.c

/*
 *  acpi_osl.c - OS-dependent functions ($Revision: 83 $)
 *
 *  Copyright (C) 2000       Andrew Henroid
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (c) 2008 Intel Corporation
 *   Author: Matthew Wilcox <willy@linux.intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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/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 unsigned int acpi_irq_irq;
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;
static struct workqueue_struct *kacpi_hotplug_wq;

struct acpi_res_list {
        resource_size_t start;
        resource_size_t end;
        acpi_adr_space_type resource_type; /* IO port, System memory, ...*/
        char name[5];   /* only can have a length of 4 chars, make use of this
                           one instead of res->name, no need to kalloc then */
        struct list_head resource_list;
        int count;
};

static LIST_HEAD(resource_list_head);
static DEFINE_SPINLOCK(acpi_res_lock);

/*
 * 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;
        struct kref ref;
};

static LIST_HEAD(acpi_ioremaps);
static DEFINE_SPINLOCK(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(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 *addr,
        unsigned int length, char *desc)
{
        if (!addr->address || !length)
                return;

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

acpi_physical_address __init acpi_os_get_root_pointer(void)
{
        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;
}

/* 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;
}

void __iomem *__init_refok
acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
        struct acpi_ioremap *map, *tmp_map;
        unsigned long flags;
        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);

        map = kzalloc(sizeof(*map), GFP_KERNEL);
        if (!map)
                return NULL;

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

        INIT_LIST_HEAD(&map->list);
        map->virt = virt;
        map->phys = pg_off;
        map->size = pg_sz;
        kref_init(&map->ref);

        spin_lock_irqsave(&acpi_ioremap_lock, flags);
        /* Check if page has already been mapped. */
        tmp_map = acpi_map_lookup(phys, size);
        if (tmp_map) {
                kref_get(&tmp_map->ref);
                spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
                iounmap(map->virt);
                kfree(map);
                return tmp_map->virt + (phys - tmp_map->phys);
        }
        list_add_tail_rcu(&map->list, &acpi_ioremaps);
        spin_unlock_irqrestore(&acpi_ioremap_lock, flags);

        return map->virt + (phys - map->phys);
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);

static void acpi_kref_del_iomap(struct kref *ref)
{
        struct acpi_ioremap *map;

        map = container_of(ref, struct acpi_ioremap, ref);
        list_del_rcu(&map->list);
}

void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{
        struct acpi_ioremap *map;
        unsigned long flags;
        int del;

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

        spin_lock_irqsave(&acpi_ioremap_lock, flags);
        map = acpi_map_lookup_virt(virt, size);
        if (!map) {
                spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
                printk(KERN_ERR PREFIX "%s: bad address %p\n", __func__, virt);
                dump_stack();
                return;
        }

        del = kref_put(&map->ref, acpi_kref_del_iomap);
        spin_unlock_irqrestore(&acpi_ioremap_lock, flags);

        if (!del)
                return;

        synchronize_rcu();
        iounmap(map->virt);
        kfree(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 *addr)
{
        void __iomem *virt;

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

        if (!addr->address || !addr->bit_width)
                return -EINVAL;

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

        return 0;
}
EXPORT_SYMBOL_GPL(acpi_os_map_generic_address);

void acpi_os_unmap_generic_address(struct acpi_generic_address *addr)
{
        void __iomem *virt;
        unsigned long flags;
        acpi_size size = addr->bit_width / 8;

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

        if (!addr->address || !addr->bit_width)
                return;

        spin_lock_irqsave(&acpi_ioremap_lock, flags);
        virt = acpi_map_vaddr_lookup(addr->address, size);
        spin_unlock_irqrestore(&acpi_ioremap_lock, flags);

        acpi_os_unmap_memory(virt, size);
}
EXPORT_SYMBOL_GPL(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;
}

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();

        /*
         * Ignore the GSI from the core, and use the value in our copy of the
         * FADT. It may not be the same if an interrupt source override exists
         * for the SCI.
         */
        gsi = acpi_gbl_FADT.sci_interrupt;
        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);
                return AE_NOT_ACQUIRED;
        }
        acpi_irq_irq = irq;

        return AE_OK;
}

acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
{
        if (irq) {
                free_irq(irq, acpi_irq);
                acpi_irq_handler = NULL;
                acpi_irq_irq = 0;
        }

        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);

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

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

        return AE_OK;
}

acpi_status
acpi_os_write_memory(acpi_physical_address phys_addr, u32 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;
        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(NULL);

        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 *context)
{
        flush_workqueue(kacpid_wq);
        flush_workqueue(kacpi_notify_wq);
}

EXPORT_SYMBOL(acpi_os_wait_events_complete);

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

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];

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)
{
        struct acpi_res_list *res_list_elem;
        int ioport = 0, clash = 0;

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

        ioport = res->flags & IORESOURCE_IO;

        spin_lock(&acpi_res_lock);
        list_for_each_entry(res_list_elem, &resource_list_head,
                            resource_list) {
                if (ioport && (res_list_elem->resource_type
                               != ACPI_ADR_SPACE_SYSTEM_IO))
                        continue;
                if (!ioport && (res_list_elem->resource_type
                                != ACPI_ADR_SPACE_SYSTEM_MEMORY))
                        continue;

                if (res->end < res_list_elem->start
                    || res_list_elem->end < res->start)
                        continue;
                clash = 1;
                break;
        }
        spin_unlock(&acpi_res_lock);

        if (clash) {
                if (acpi_enforce_resources != ENFORCE_RESOURCES_NO) {
                        printk(KERN_WARNING "ACPI: resource %s %pR"
                               " conflicts with ACPI region %s "
                               "[%s 0x%zx-0x%zx]\n",
                               res->name, res, res_list_elem->name,
                               (res_list_elem->resource_type ==
                                ACPI_ADR_SPACE_SYSTEM_IO) ? "io" : "mem",
                               (size_t) res_list_elem->start,
                               (size_t) res_list_elem->end);
                        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);

/*
 * 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);
}

static inline int acpi_res_list_add(struct acpi_res_list *res)
{
        struct acpi_res_list *res_list_elem;

        list_for_each_entry(res_list_elem, &resource_list_head,
                            resource_list) {

                if (res->resource_type == res_list_elem->resource_type &&
                    res->start == res_list_elem->start &&
                    res->end == res_list_elem->end) {

                        /*
                         * The Region(addr,len) already exist in the list,
                         * just increase the count
                         */

                        res_list_elem->count++;
                        return 0;
                }
        }

        res->count = 1;
        list_add(&res->resource_list, &resource_list_head);
        return 1;
}

static inline void acpi_res_list_del(struct acpi_res_list *res)
{
        struct acpi_res_list *res_list_elem;

        list_for_each_entry(res_list_elem, &resource_list_head,
                            resource_list) {

                if (res->resource_type == res_list_elem->resource_type &&
                    res->start == res_list_elem->start &&
                    res->end == res_list_elem->end) {

                        /*
                         * If the res count is decreased to 0,
                         * remove and free it
                         */

                        if (--res_list_elem->count == 0) {
                                list_del(&res_list_elem->resource_list);
                                kfree(res_list_elem);
                        }
                        return;
                }
        }
}

acpi_status
acpi_os_invalidate_address(
    u8                   space_id,
    acpi_physical_address   address,
    acpi_size               length)
{
        struct acpi_res_list res;

        switch (space_id) {
        case ACPI_ADR_SPACE_SYSTEM_IO:
        case ACPI_ADR_SPACE_SYSTEM_MEMORY:
                /* Only interference checks against SystemIO and SystemMemory
                   are needed */
                res.start = address;
                res.end = address + length - 1;
                res.resource_type = space_id;
                spin_lock(&acpi_res_lock);
                acpi_res_list_del(&res);
                spin_unlock(&acpi_res_lock);
                break;
        case ACPI_ADR_SPACE_PCI_CONFIG:
        case ACPI_ADR_SPACE_EC:
        case ACPI_ADR_SPACE_SMBUS:
        case ACPI_ADR_SPACE_CMOS:
        case ACPI_ADR_SPACE_PCI_BAR_TARGET:
        case ACPI_ADR_SPACE_DATA_TABLE:
        case ACPI_ADR_SPACE_FIXED_HARDWARE:
                break;
        }
        return AE_OK;
}

/******************************************************************************
 *
 * FUNCTION:    acpi_os_validate_address
 *
 * PARAMETERS:  space_id             - ACPI space ID
 *              address             - Physical address
 *              length              - Address length
 *
 * RETURN:      AE_OK if address/length is valid for the space_id. Otherwise,
 *              should return AE_AML_ILLEGAL_ADDRESS.
 *
 * DESCRIPTION: Validate a system address via the host OS. Used to validate
 *              the addresses accessed by AML operation regions.
 *
 *****************************************************************************/

acpi_status
acpi_os_validate_address (
    u8                   space_id,
    acpi_physical_address   address,
    acpi_size               length,
    char *name)
{
        struct acpi_res_list *res;
        int added;
        if (acpi_enforce_resources == ENFORCE_RESOURCES_NO)
                return AE_OK;

        switch (space_id) {
        case ACPI_ADR_SPACE_SYSTEM_IO:
        case ACPI_ADR_SPACE_SYSTEM_MEMORY:
                /* Only interference checks against SystemIO and SystemMemory
                   are needed */
                res = kzalloc(sizeof(struct acpi_res_list), GFP_KERNEL);
                if (!res)
                        return AE_OK;
                /* ACPI names are fixed to 4 bytes, still better use strlcpy */
                strlcpy(res->name, name, 5);
                res->start = address;
                res->end = address + length - 1;
                res->resource_type = space_id;
                spin_lock(&acpi_res_lock);
                added = acpi_res_list_add(res);
                spin_unlock(&acpi_res_lock);
                pr_debug("%s %s resource: start: 0x%llx, end: 0x%llx, "
                         "name: %s\n", added ? "Added" : "Already exist",
                         (space_id == ACPI_ADR_SPACE_SYSTEM_IO)
                         ? "SystemIO" : "System Memory",
                         (unsigned long long)res->start,
                         (unsigned long long)res->end,
                         res->name);
                if (!added)
                        kfree(res);
                break;
        case ACPI_ADR_SPACE_PCI_CONFIG:
        case ACPI_ADR_SPACE_EC:
        case ACPI_ADR_SPACE_SMBUS:
        case ACPI_ADR_SPACE_CMOS:
        case ACPI_ADR_SPACE_PCI_BAR_TARGET:
        case ACPI_ADR_SPACE_DATA_TABLE:
        case ACPI_ADR_SPACE_FIXED_HARDWARE:
                break;
        }
        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 = create_workqueue("kacpid");
        kacpi_notify_wq = create_workqueue("kacpi_notify");
        kacpi_hotplug_wq = create_workqueue("kacpi_hotplug");
        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_irq_irq,
                                                 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;
}