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[linux-2.6.9-moxart.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>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/config.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/nmi.h>
#include <acpi/acpi.h>
#include <asm/io.h>
#include <acpi/acpi_bus.h>
#include <asm/uaccess.h>

#include <linux/efi.h>


#define _COMPONENT              ACPI_OS_SERVICES
ACPI_MODULE_NAME        ("osl")

#define PREFIX          "ACPI: "

struct acpi_os_dpc
{
    acpi_osd_exec_callback  function;
    void                    *context;
};

#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;
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;

acpi_status
acpi_os_initialize(void)
{
        return AE_OK;
}

acpi_status
acpi_os_initialize1(void)
{
        /*
         * Initialize PCI configuration space access, as we'll need to access
         * it while walking the namespace (bus 0 and root bridges w/ _BBNs).
         */
#ifdef CONFIG_ACPI_PCI
        if (!raw_pci_ops) {
                printk(KERN_ERR PREFIX "Access to PCI configuration space unavailable\n");
                return AE_NULL_ENTRY;
        }
#endif
        kacpid_wq = create_singlethread_workqueue("kacpid");
        BUG_ON(!kacpid_wq);

        return AE_OK;
}

acpi_status
acpi_os_terminate(void)
{
        if (acpi_irq_handler) {
                acpi_os_remove_interrupt_handler(acpi_irq_irq,
                                                 acpi_irq_handler);
        }

        destroy_workqueue(kacpid_wq);

        return AE_OK;
}

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("%s", buffer);
        }
#else
        printk("%s", buffer);
#endif
}

void *
acpi_os_allocate(acpi_size size)
{
        return kmalloc(size, GFP_KERNEL);
}

void
acpi_os_free(void *ptr)
{
        kfree(ptr);
}

acpi_status
acpi_os_get_root_pointer(u32 flags, struct acpi_pointer *addr)
{
        if (efi_enabled) {
                addr->pointer_type = ACPI_PHYSICAL_POINTER;
                if (efi.acpi20)
                        addr->pointer.physical =
                                (acpi_physical_address) virt_to_phys(efi.acpi20);
                else if (efi.acpi)
                        addr->pointer.physical =
                                (acpi_physical_address) virt_to_phys(efi.acpi);
                else {
                        printk(KERN_ERR PREFIX "System description tables not found\n");
                        return AE_NOT_FOUND;
                }
        } else {
                if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
                        printk(KERN_ERR PREFIX "System description tables not found\n");
                        return AE_NOT_FOUND;
                }
        }

        return AE_OK;
}

acpi_status
acpi_os_map_memory(acpi_physical_address phys, acpi_size size, void __iomem **virt)
{
        if (efi_enabled) {
                if (EFI_MEMORY_WB & efi_mem_attributes(phys)) {
                        *virt = (void __iomem *) phys_to_virt(phys);
                } else {
                        *virt = ioremap(phys, size);
                }
        } else {
                if (phys > ULONG_MAX) {
                        printk(KERN_ERR PREFIX "Cannot map memory that high\n");
                        return AE_BAD_PARAMETER;
                }
                /*
                 * ioremap checks to ensure this is in reserved space
                 */
                *virt = ioremap((unsigned long) phys, size);
        }

        if (!*virt)
                return AE_NO_MEMORY;

        return AE_OK;
}

void
acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{
        iounmap(virt);
}

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;
}

#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 %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;

#ifdef CONFIG_ACPI_CUSTOM_DSDT
        if (strncmp(existing_table->signature, "DSDT", 4) == 0)
                *new_table = (struct acpi_table_header*)AmlCode;
        else
                *new_table = NULL;
#else
        *new_table = NULL;
#endif
        return AE_OK;
}

static irqreturn_t
acpi_irq(int irq, void *dev_id, struct pt_regs *regs)
{
        return (*acpi_irq_handler)(acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
}

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

        /*
         * 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_fadt.sci_int;
        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, SA_SHIRQ, "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(u32 sec, u32 ms)
{
        current->state = TASK_INTERRUPTIBLE;
        schedule_timeout(HZ * sec + (ms * HZ) / 1000);
}

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

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

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

        if (!value)
                value = &dummy;

        switch (width)
        {
        case 8:
                *(u8*)  value = inb(port);
                break;
        case 16:
                *(u16*) value = inw(port);
                break;
        case 32:
                *(u32*) value = inl(port);
                break;
        default:
                BUG();
        }

        return AE_OK;
}

acpi_status
acpi_os_write_port(
        acpi_io_address port,
        u32             value,
        u32             width)
{
        switch (width)
        {
        case 8:
                outb(value, port);
                break;
        case 16:
                outw(value, port);
                break;
        case 32:
                outl(value, port);
                break;
        default:
                BUG();
        }

        return AE_OK;
}

acpi_status
acpi_os_read_memory(
        acpi_physical_address   phys_addr,
        u32                     *value,
        u32                     width)
{
        u32                     dummy;
        void __iomem            *virt_addr;
        int                     iomem = 0;

        if (efi_enabled) {
                if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
                        /* HACK ALERT! We can use readb/w/l on real memory too.. */
                        virt_addr = (void __iomem *) phys_to_virt(phys_addr);
                } else {
                        iomem = 1;
                        virt_addr = ioremap(phys_addr, width);
                }
        } else
                virt_addr = (void __iomem *) phys_to_virt(phys_addr);
        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 (efi_enabled) {
                if (iomem)
                        iounmap(virt_addr);
        }

        return AE_OK;
}

acpi_status
acpi_os_write_memory(
        acpi_physical_address   phys_addr,
        u32                     value,
        u32                     width)
{
        void __iomem            *virt_addr;
        int                     iomem = 0;

        if (efi_enabled) {
                if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
                        /* HACK ALERT! We can use writeb/w/l on real memory too */
                        virt_addr = (void __iomem *) phys_to_virt(phys_addr);
                } else {
                        iomem = 1;
                        virt_addr = ioremap(phys_addr, width);
                }
        } else
                virt_addr = (void __iomem *) phys_to_virt(phys_addr);

        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 (iomem)
                iounmap(virt_addr);

        return AE_OK;
}

#ifdef CONFIG_ACPI_PCI

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

        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;
        }

        BUG_ON(!raw_pci_ops);

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

        return (result ? AE_ERROR : AE_OK);
}

acpi_status
acpi_os_write_pci_configuration (struct acpi_pci_id *pci_id, u32 reg, acpi_integer 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;
        }

        BUG_ON(!raw_pci_ops);

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

        return (result ? AE_ERROR : AE_OK);
}

/* TODO: Change code to take advantage of driver model more */
void
acpi_os_derive_pci_id_2 (
        acpi_handle             rhandle,        /* upper bound  */
        acpi_handle             chandle,        /* current node */
        struct acpi_pci_id      **id,
        int                     *is_bridge,
        u8                      *bus_number)
{
        acpi_handle             handle;
        struct acpi_pci_id      *pci_id = *id;
        acpi_status             status;
        unsigned long           temp;
        acpi_object_type        type;
        u8                      tu8;

        acpi_get_parent(chandle, &handle);
        if (handle != rhandle) {
                acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge, bus_number);

                status = acpi_get_type(handle, &type);
                if ( (ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE) )
                        return;

                status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &temp);
                if (ACPI_SUCCESS(status)) {
                        pci_id->device  = ACPI_HIWORD (ACPI_LODWORD (temp));
                        pci_id->function = ACPI_LOWORD (ACPI_LODWORD (temp));

                        if (*is_bridge)
                                pci_id->bus = *bus_number;

                        /* any nicer way to get bus number of bridge ? */
                        status = acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8, 8);
                        if (ACPI_SUCCESS(status) &&
                            ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
                                status = acpi_os_read_pci_configuration(pci_id, 0x18, &tu8, 8);
                                if (!ACPI_SUCCESS(status)) {
                                        /* Certainly broken...  FIX ME */
                                        return;
                                }
                                *is_bridge = 1;
                                pci_id->bus = tu8;
                                status = acpi_os_read_pci_configuration(pci_id, 0x19, &tu8, 8);
                                if (ACPI_SUCCESS(status)) {
                                        *bus_number = tu8;
                                }
                        } else
                                *is_bridge = 0;
                }
        }
}

void
acpi_os_derive_pci_id (
        acpi_handle             rhandle,        /* upper bound  */
        acpi_handle             chandle,        /* current node */
        struct acpi_pci_id      **id)
{
        int is_bridge = 1;
        u8 bus_number = (*id)->bus;

        acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
}

#else /*!CONFIG_ACPI_PCI*/

acpi_status
acpi_os_write_pci_configuration (
        struct acpi_pci_id      *pci_id,
        u32                     reg,
        acpi_integer            value,
        u32                     width)
{
        return (AE_SUPPORT);
}

acpi_status
acpi_os_read_pci_configuration (
        struct acpi_pci_id      *pci_id,
        u32                     reg,
        void                    *value,
        u32                     width)
{
        return (AE_SUPPORT);
}

void
acpi_os_derive_pci_id (
        acpi_handle             rhandle,        /* upper bound  */
        acpi_handle             chandle,        /* current node */
        struct acpi_pci_id      **id)
{
}

#endif /*CONFIG_ACPI_PCI*/

static void
acpi_os_execute_deferred (
        void *context)
{
        struct acpi_os_dpc      *dpc = NULL;

        ACPI_FUNCTION_TRACE ("os_execute_deferred");

        dpc = (struct acpi_os_dpc *) context;
        if (!dpc) {
                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Invalid (NULL) context.\n"));
                return_VOID;
        }

        dpc->function(dpc->context);

        kfree(dpc);

        return_VOID;
}

acpi_status
acpi_os_queue_for_execution(
        u32                     priority,
        acpi_osd_exec_callback  function,
        void                    *context)
{
        acpi_status             status = AE_OK;
        struct acpi_os_dpc      *dpc;
        struct work_struct      *task;

        ACPI_FUNCTION_TRACE ("os_queue_for_execution");

        ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Scheduling function [%p(%p)] for deferred execution.\n", function, context));

        if (!function)
                return_ACPI_STATUS (AE_BAD_PARAMETER);

        /*
         * Allocate/initialize DPC structure.  Note that this memory will be
         * freed by the callee.  The kernel handles the tq_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 tq_struct.
         * We can save time and code by allocating the DPC and tq_structs
         * from the same memory.
         */

        dpc = kmalloc(sizeof(struct acpi_os_dpc)+sizeof(struct work_struct), GFP_ATOMIC);
        if (!dpc)
                return_ACPI_STATUS (AE_NO_MEMORY);

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

        task = (void *)(dpc+1);
        INIT_WORK(task, acpi_os_execute_deferred, (void*)dpc);

        if (!queue_work(kacpid_wq, task)) {
                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Call to queue_work() failed.\n"));
                kfree(dpc);
                status = AE_ERROR;
        }

        return_ACPI_STATUS (status);
}

void
acpi_os_wait_events_complete(
        void *context)
{
        flush_workqueue(kacpid_wq);
}

/*
 * Allocate the memory for a spinlock and initialize it.
 */
acpi_status
acpi_os_create_lock (
        acpi_handle     *out_handle)
{
        spinlock_t *lock_ptr;

        ACPI_FUNCTION_TRACE ("os_create_lock");

        lock_ptr = acpi_os_allocate(sizeof(spinlock_t));

        spin_lock_init(lock_ptr);

        ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Creating spinlock[%p].\n", lock_ptr));

        *out_handle = lock_ptr;

        return_ACPI_STATUS (AE_OK);
}


/*
 * Deallocate the memory for a spinlock.
 */
void
acpi_os_delete_lock (
        acpi_handle     handle)
{
        ACPI_FUNCTION_TRACE ("os_create_lock");

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

        acpi_os_free(handle);

        return_VOID;
}

/*
 * Acquire a spinlock.
 *
 * handle is a pointer to the spinlock_t.
 * flags is *not* the result of save_flags - it is an ACPI-specific flag variable
 *   that indicates whether we are at interrupt level.
 */
void
acpi_os_acquire_lock (
        acpi_handle     handle,
        u32             flags)
{
        ACPI_FUNCTION_TRACE ("os_acquire_lock");

        ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Acquiring spinlock[%p] from %s level\n", handle,
                ((flags & ACPI_NOT_ISR) ? "non-interrupt" : "interrupt")));

        if (flags & ACPI_NOT_ISR)
                ACPI_DISABLE_IRQS();

        spin_lock((spinlock_t *)handle);

        return_VOID;
}


/*
 * Release a spinlock. See above.
 */
void
acpi_os_release_lock (
        acpi_handle     handle,
        u32             flags)
{
        ACPI_FUNCTION_TRACE ("os_release_lock");

        ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Releasing spinlock[%p] from %s level\n", handle,
                ((flags & ACPI_NOT_ISR) ? "non-interrupt" : "interrupt")));

        spin_unlock((spinlock_t *)handle);

        if (flags & ACPI_NOT_ISR)
                ACPI_ENABLE_IRQS();

        return_VOID;
}


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

        ACPI_FUNCTION_TRACE ("os_create_semaphore");

        sem = acpi_os_allocate(sizeof(struct semaphore));
        if (!sem)
                return_ACPI_STATUS (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_ACPI_STATUS (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;

        ACPI_FUNCTION_TRACE ("os_delete_semaphore");

        if (!sem)
                return_ACPI_STATUS (AE_BAD_PARAMETER);

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

        acpi_os_free(sem); sem =  NULL;

        return_ACPI_STATUS (AE_OK);
}


/*
 * TODO: The kernel doesn't have a 'down_timeout' function -- had to
 * improvise.  The process is to sleep for one scheduler quantum
 * until the semaphore becomes available.  Downside is that this
 * may result in starvation for timeout-based waits when there's
 * lots of semaphore activity.
 *
 * 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;
        int                     ret = 0;

        ACPI_FUNCTION_TRACE ("os_wait_semaphore");

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

        if (units > 1)
                return_ACPI_STATUS (AE_SUPPORT);

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

        if (in_atomic())
                timeout = 0;

        switch (timeout)
        {
                /*
                 * No Wait:
                 * --------
                 * A zero timeout value indicates that we shouldn't wait - just
                 * acquire the semaphore if available otherwise return AE_TIME
                 * (a.k.a. 'would block').
                 */
                case 0:
                if(down_trylock(sem))
                        status = AE_TIME;
                break;

                /*
                 * Wait Indefinitely:
                 * ------------------
                 */
                case ACPI_WAIT_FOREVER:
                down(sem);
                break;

                /*
                 * Wait w/ Timeout:
                 * ----------------
                 */
                default:
                // TODO: A better timeout algorithm?
                {
                        int i = 0;
                        static const int quantum_ms = 1000/HZ;

                        ret = down_trylock(sem);
                        for (i = timeout; (i > 0 && ret < 0); i -= quantum_ms) {
                                current->state = TASK_INTERRUPTIBLE;
                                schedule_timeout(1);
                                ret = down_trylock(sem);
                        }
        
                        if (ret != 0)
                                status = AE_TIME;
                }
                break;
        }

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

        return_ACPI_STATUS (status);
}


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

        ACPI_FUNCTION_TRACE ("os_signal_semaphore");

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

        if (units > 1)
                return_ACPI_STATUS (AE_SUPPORT);

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

        up(sem);

        return_ACPI_STATUS (AE_OK);
}

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;
}

/* Assumes no unreadable holes inbetween */
u8
acpi_os_readable(void *ptr, acpi_size len)
{
#if defined(__i386__) || defined(__x86_64__) 
        char tmp;
        return !__get_user(tmp, (char __user *)ptr) && !__get_user(tmp, (char __user *)ptr + len - 1);
#endif
        return 1;
}

u8
acpi_os_writable(void *ptr, acpi_size len)
{
        /* could do dummy write (racy) or a kernel page table lookup.
           The later may be difficult at early boot when kmap doesn't work yet. */
        return 1;
}

u32
acpi_os_get_thread_id (void)
{
        if (!in_atomic())
                return current->pid;

        return 0;
}

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:
                {
                        char *bp_info = (char*) info;

                        printk(KERN_ERR "ACPI breakpoint: %s\n", bp_info);
                }
        default:
                break;
        }

        return AE_OK;
}

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);

/*
 * _OSI control
 * empty string disables _OSI
 * TBD additional string adds to _OSI
 */
int __init
acpi_osi_setup(char *str)
{
        if (str == NULL || *str == '\0') {
                printk(KERN_INFO PREFIX "_OSI method disabled\n");
                acpi_gbl_create_osi_method = FALSE;
        } else
        {
                /* TBD */
                printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n", str);
        }

        return 1;
}

__setup("acpi_osi=", acpi_osi_setup);

/* enable serialization to combat AE_ALREADY_EXISTS errors */
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);

/*
 * Wake and Run-Time GPES are expected to be separate.
 * We disable wake-GPEs at run-time to prevent spurious
 * interrupts.
 *
 * However, if a system exists that shares Wake and
 * Run-time events on the same GPE this flag is available
 * to tell Linux to keep the wake-time GPEs enabled at run-time.
 */
int __init
acpi_wake_gpes_always_on_setup(char *str)
{
        printk(KERN_INFO PREFIX "wake GPEs not disabled\n");

        acpi_gbl_leave_wake_gpes_disabled = FALSE;

        return 1;
}

__setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);