/****************************************************************************** * * Module Name: evglock - Global Lock support * *****************************************************************************/ /****************************************************************************** * * 1. Copyright Notice * * Some or all of this work - Copyright (c) 1999 - 2018, 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 "acpi.h" #include "accommon.h" #include "acevents.h" #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 */