FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/components/events/evglock.c

     /******************************************************************************
      *
      * Module Name: evglock - Global Lock support
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
      * 1. Copyright Notice
     *
     * Some or all of this work - Copyright (c) 1999 - 2022, Intel Corp.
     * All rights reserved.
     *
     * 2. License
     *
     * 2.1. This is your license from Intel Corp. under its intellectual property
     * rights. You may have additional license terms from the party that provided
     * you this software, covering your right to use that party's intellectual
     * property rights.
     *
     * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
     * copy of the source code appearing in this file ("Covered Code") an
     * irrevocable, perpetual, worldwide license under Intel's copyrights in the
     * base code distributed originally by Intel ("Original Intel Code") to copy,
     * make derivatives, distribute, use and display any portion of the Covered
     * Code in any form, with the right to sublicense such rights; and
     *
     * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
     * license (with the right to sublicense), under only those claims of Intel
     * patents that are infringed by the Original Intel Code, to make, use, sell,
     * offer to sell, and import the Covered Code and derivative works thereof
     * solely to the minimum extent necessary to exercise the above copyright
     * license, and in no event shall the patent license extend to any additions
     * to or modifications of the Original Intel Code. No other license or right
     * is granted directly or by implication, estoppel or otherwise;
     *
     * The above copyright and patent license is granted only if the following
     * conditions are met:
     *
     * 3. Conditions
     *
     * 3.1. Redistribution of Source with Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification with rights to further distribute source must include
     * the above Copyright Notice, the above License, this list of Conditions,
     * and the following Disclaimer and Export Compliance provision. In addition,
     * Licensee must cause all Covered Code to which Licensee contributes to
     * contain a file documenting the changes Licensee made to create that Covered
     * Code and the date of any change. Licensee must include in that file the
     * documentation of any changes made by any predecessor Licensee. Licensee
     * must include a prominent statement that the modification is derived,
     * directly or indirectly, from Original Intel Code.
     *
     * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification without rights to further distribute source must
     * include the following Disclaimer and Export Compliance provision in the
     * documentation and/or other materials provided with distribution. In
     * addition, Licensee may not authorize further sublicense of source of any
     * portion of the Covered Code, and must include terms to the effect that the
     * license from Licensee to its licensee is limited to the intellectual
     * property embodied in the software Licensee provides to its licensee, and
     * not to intellectual property embodied in modifications its licensee may
     * make.
     *
     * 3.3. Redistribution of Executable. Redistribution in executable form of any
     * substantial portion of the Covered Code or modification must reproduce the
     * above Copyright Notice, and the following Disclaimer and Export Compliance
     * provision in the documentation and/or other materials provided with the
     * distribution.
     *
     * 3.4. Intel retains all right, title, and interest in and to the Original
     * Intel Code.
     *
     * 3.5. Neither the name Intel nor any other trademark owned or controlled by
     * Intel shall be used in advertising or otherwise to promote the sale, use or
     * other dealings in products derived from or relating to the Covered Code
     * without prior written authorization from Intel.
     *
     * 4. Disclaimer and Export Compliance
     *
     * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
     * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
     * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
     * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
     * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
     * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
     * PARTICULAR PURPOSE.
     *
     * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
     * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
     * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
     * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
     * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
     * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
     * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
     * LIMITED REMEDY.
     *
     * 4.3. Licensee shall not export, either directly or indirectly, any of this
    * software or system incorporating such software without first obtaining any
    * required license or other approval from the U. S. Department of Commerce or
    * any other agency or department of the United States Government. In the
    * event Licensee exports any such software from the United States or
    * re-exports any such software from a foreign destination, Licensee shall
    * ensure that the distribution and export/re-export of the software is in
    * compliance with all laws, regulations, orders, or other restrictions of the
    * U.S. Export Administration Regulations. Licensee agrees that neither it nor
    * any of its subsidiaries will export/re-export any technical data, process,
    * software, or service, directly or indirectly, to any country for which the
    * United States government or any agency thereof requires an export license,
    * other governmental approval, or letter of assurance, without first obtaining
    * such license, approval or letter.
    *
    *****************************************************************************
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * following license:
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    * 1. Redistributions of source code must retain the above copyright
    *    notice, this list of conditions, and the following disclaimer,
    *    without modification.
    * 2. Redistributions in binary form must reproduce at minimum a disclaimer
    *    substantially similar to the "NO WARRANTY" disclaimer below
    *    ("Disclaimer") and any redistribution must be conditioned upon
    *    including a substantially similar Disclaimer requirement for further
    *    binary redistribution.
    * 3. Neither the names of the above-listed copyright holders nor the names
    *    of any contributors may be used to endorse or promote products derived
    *    from this software without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * GNU General Public License ("GPL") version 2 as published by the Free
    * Software Foundation.
    *
    *****************************************************************************/
   
   #include <contrib/dev/acpica/include/acpi.h>
   #include <contrib/dev/acpica/include/accommon.h>
   #include <contrib/dev/acpica/include/acevents.h>
   #include <contrib/dev/acpica/include/acinterp.h>
   
   #define _COMPONENT          ACPI_EVENTS
           ACPI_MODULE_NAME    ("evglock")
   
   #if (!ACPI_REDUCED_HARDWARE) /* Entire module */
   
   /* Local prototypes */
   
   static UINT32
   AcpiEvGlobalLockHandler (
       void                    *Context);
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiEvInitGlobalLockHandler
    *
    * PARAMETERS:  None
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Install a handler for the global lock release event
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiEvInitGlobalLockHandler (
       void)
   {
       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);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiEvRemoveGlobalLockHandler
    *
    * PARAMETERS:  None
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Remove the handler for the Global Lock
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiEvRemoveGlobalLockHandler (
       void)
   {
       ACPI_STATUS             Status;
   
   
       ACPI_FUNCTION_TRACE (EvRemoveGlobalLockHandler);
   
   
       AcpiGbl_GlobalLockPresent = FALSE;
       Status = AcpiRemoveFixedEventHandler (ACPI_EVENT_GLOBAL,
           AcpiEvGlobalLockHandler);
   
       AcpiOsDeleteLock (AcpiGbl_GlobalLockPendingLock);
       return_ACPI_STATUS (Status);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiEvGlobalLockHandler
    *
    * PARAMETERS:  Context         - From thread interface, not used
    *
    * RETURN:      ACPI_INTERRUPT_HANDLED
    *
    * DESCRIPTION: Invoked directly from the SCI handler when a global lock
    *              release interrupt occurs. If there is actually a pending
    *              request for the lock, signal the waiting thread.
    *
    ******************************************************************************/
   
   static UINT32
   AcpiEvGlobalLockHandler (
       void                    *Context)
   {
       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);
   }
   
   
   /******************************************************************************
    *
    * FUNCTION:    AcpiEvAcquireGlobalLock
    *
    * PARAMETERS:  Timeout         - Max time to wait for the lock, in millisec.
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Attempt to gain ownership of the Global Lock.
    *
    * MUTEX:       Interpreter must be locked
    *
    * Note: The original implementation allowed multiple threads to "acquire" the
    * Global Lock, and the OS would hold the lock until the last thread had
    * released it. However, this could potentially starve the BIOS out of the
    * lock, especially in the case where there is a tight handshake between the
    * Embedded Controller driver and the BIOS. Therefore, this implementation
    * allows only one thread to acquire the HW Global Lock at a time, and makes
    * the global lock appear as a standard mutex on the OS side.
    *
    *****************************************************************************/
   
   ACPI_STATUS
   AcpiEvAcquireGlobalLock (
       UINT16                  Timeout)
   {
       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);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiEvReleaseGlobalLock
    *
    * PARAMETERS:  None
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Releases ownership of the Global Lock.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiEvReleaseGlobalLock (
       void)
   {
       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);
   }
   
   #endif /* !ACPI_REDUCED_HARDWARE */

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