evglock.c File Reference

#include "acpi.h"
#include "accommon.h"
#include "acevents.h"
#include "acinterp.h"

Include dependency graph for evglock.c:

Go to the source code of this file.

Macros
#define	_COMPONENT   ACPI_EVENTS

Functions
static UINT32	AcpiEvGlobalLockHandler (void *Context)
ACPI_STATUS	AcpiEvInitGlobalLockHandler (void)
ACPI_STATUS	AcpiEvRemoveGlobalLockHandler (void)
ACPI_STATUS	AcpiEvAcquireGlobalLock (UINT16 Timeout)
ACPI_STATUS	AcpiEvReleaseGlobalLock (void)

Macro Definition Documentation

_COMPONENT

#define _COMPONENT   ACPI_EVENTS

Definition at line 49 of file evglock.c.

Function Documentation

AcpiEvAcquireGlobalLock()

ACPI_STATUS AcpiEvAcquireGlobalLock

(

UINT16

Timeout

)

Definition at line 230 of file evglock.c.

{
    ACPI_CPU_FLAGS          Flags;
    ACPI_STATUS             Status;
    BOOLEAN                 Acquired = FALSE;
 
 
    ACPI_FUNCTION_TRACE (EvAcquireGlobalLock);
 
 
    /*
     * Only one thread can acquire the GL at a time, the GlobalLockMutex
     * enforces this. This interface releases the interpreter if we must wait.
     */
    Status = AcpiExSystemWaitMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex,
                Timeout);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }
 
    /*
     * Update the global lock handle and check for wraparound. The handle is
     * only used for the external global lock interfaces, but it is updated
     * here to properly handle the case where a single thread may acquire the
     * lock via both the AML and the AcpiAcquireGlobalLock interfaces. The
     * handle is therefore updated on the first acquire from a given thread
     * regardless of where the acquisition request originated.
     */
    AcpiGbl_GlobalLockHandle++;
    if (AcpiGbl_GlobalLockHandle == 0)
    {
        AcpiGbl_GlobalLockHandle = 1;
    }
 
    /*
     * Make sure that a global lock actually exists. If not, just
     * treat the lock as a standard mutex.
     */
    if (!AcpiGbl_GlobalLockPresent)
    {
        AcpiGbl_GlobalLockAcquired = TRUE;
        return_ACPI_STATUS (AE_OK);
    }
 
    Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
 
    do
    {
        /* Attempt to acquire the actual hardware lock */
 
        ACPI_ACQUIRE_GLOBAL_LOCK (AcpiGbl_FACS, Acquired);
        if (Acquired)
        {
            AcpiGbl_GlobalLockAcquired = TRUE;
            ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
                "Acquired hardware Global Lock\n"));
            break;
        }
 
        /*
         * Did not get the lock. The pending bit was set above, and
         * we must now wait until we receive the global lock
         * released interrupt.
         */
        AcpiGbl_GlobalLockPending = TRUE;
        AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
 
        ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
            "Waiting for hardware Global Lock\n"));
 
        /*
         * Wait for handshake with the global lock interrupt handler.
         * This interface releases the interpreter if we must wait.
         */
        Status = AcpiExSystemWaitSemaphore (
            AcpiGbl_GlobalLockSemaphore, ACPI_WAIT_FOREVER);
 
        Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
 
    } while (ACPI_SUCCESS (Status));
 
    AcpiGbl_GlobalLockPending = FALSE;
    AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
 
    return_ACPI_STATUS (Status);
}

Referenced by AcpiExAcquireMutexObject().

AcpiEvGlobalLockHandler()

static UINT32 AcpiEvGlobalLockHandler ( void *  Context )

static

Definition at line 168 of file evglock.c.

{
    ACPI_STATUS             Status;
    ACPI_CPU_FLAGS          Flags;
 
 
    Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
 
    /*
     * If a request for the global lock is not actually pending,
     * we are done. This handles "spurious" global lock interrupts
     * which are possible (and have been seen) with bad BIOSs.
     */
    if (!AcpiGbl_GlobalLockPending)
    {
        goto CleanupAndExit;
    }
 
    /*
     * Send a unit to the global lock semaphore. The actual acquisition
     * of the global lock will be performed by the waiting thread.
     */
    Status = AcpiOsSignalSemaphore (AcpiGbl_GlobalLockSemaphore, 1);
    if (ACPI_FAILURE (Status))
    {
        ACPI_ERROR ((AE_INFO, "Could not signal Global Lock semaphore"));
    }
 
    AcpiGbl_GlobalLockPending = FALSE;
 
 
CleanupAndExit:
 
    AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
    return (ACPI_INTERRUPT_HANDLED);
}

Referenced by AcpiEvInitGlobalLockHandler(), and AcpiEvRemoveGlobalLockHandler().

AcpiEvInitGlobalLockHandler()

ACPI_STATUS AcpiEvInitGlobalLockHandler

(

void

)

Definition at line 74 of file evglock.c.

{
    ACPI_STATUS             Status;
 
 
    ACPI_FUNCTION_TRACE (EvInitGlobalLockHandler);
 
 
    /* If Hardware Reduced flag is set, there is no global lock */
 
    if (AcpiGbl_ReducedHardware)
    {
        return_ACPI_STATUS (AE_OK);
    }
 
    /* Attempt installation of the global lock handler */
 
    Status = AcpiInstallFixedEventHandler (ACPI_EVENT_GLOBAL,
        AcpiEvGlobalLockHandler, NULL);
 
    /*
     * If the global lock does not exist on this platform, the attempt to
     * enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick).
     * Map to AE_OK, but mark global lock as not present. Any attempt to
     * actually use the global lock will be flagged with an error.
     */
    AcpiGbl_GlobalLockPresent = FALSE;
    if (Status == AE_NO_HARDWARE_RESPONSE)
    {
        ACPI_ERROR ((AE_INFO,
            "No response from Global Lock hardware, disabling lock"));
 
        return_ACPI_STATUS (AE_OK);
    }
 
    Status = AcpiOsCreateLock (&AcpiGbl_GlobalLockPendingLock);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }
 
    AcpiGbl_GlobalLockPending = FALSE;
    AcpiGbl_GlobalLockPresent = TRUE;
    return_ACPI_STATUS (Status);
}

Referenced by AcpiEvInstallXruptHandlers().

AcpiEvReleaseGlobalLock()

ACPI_STATUS AcpiEvReleaseGlobalLock

(

void

)

Definition at line 333 of file evglock.c.

{
    BOOLEAN                 Pending = FALSE;
    ACPI_STATUS             Status = AE_OK;
 
 
    ACPI_FUNCTION_TRACE (EvReleaseGlobalLock);
 
 
    /* Lock must be already acquired */
 
    if (!AcpiGbl_GlobalLockAcquired)
    {
        ACPI_WARNING ((AE_INFO,
            "Cannot release the ACPI Global Lock, it has not been acquired"));
        return_ACPI_STATUS (AE_NOT_ACQUIRED);
    }
 
    if (AcpiGbl_GlobalLockPresent)
    {
        /* Allow any thread to release the lock */
 
        ACPI_RELEASE_GLOBAL_LOCK (AcpiGbl_FACS, Pending);
 
        /*
         * If the pending bit was set, we must write GBL_RLS to the control
         * register
         */
        if (Pending)
        {
            Status = AcpiWriteBitRegister (
                ACPI_BITREG_GLOBAL_LOCK_RELEASE, ACPI_ENABLE_EVENT);
        }
 
        ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Released hardware Global Lock\n"));
    }
 
    AcpiGbl_GlobalLockAcquired = FALSE;
 
    /* Release the local GL mutex */
 
    AcpiOsReleaseMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex);
    return_ACPI_STATUS (Status);
}

Referenced by AcpiExReleaseAllMutexes(), and AcpiExReleaseMutexObject().

AcpiEvRemoveGlobalLockHandler()

ACPI_STATUS AcpiEvRemoveGlobalLockHandler

(

void

)

Definition at line 135 of file evglock.c.

{
    ACPI_STATUS             Status;
 
 
    ACPI_FUNCTION_TRACE (EvRemoveGlobalLockHandler);
 
 
    AcpiGbl_GlobalLockPresent = FALSE;
    Status = AcpiRemoveFixedEventHandler (ACPI_EVENT_GLOBAL,
        AcpiEvGlobalLockHandler);
 
    AcpiOsDeleteLock (AcpiGbl_GlobalLockPendingLock);
    return_ACPI_STATUS (Status);
}

Referenced by AcpiEvTerminate().