From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/acpi/acpica/evglock.c | 344 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 344 insertions(+) create mode 100644 drivers/acpi/acpica/evglock.c (limited to 'drivers/acpi/acpica/evglock.c') diff --git a/drivers/acpi/acpica/evglock.c b/drivers/acpi/acpica/evglock.c new file mode 100644 index 000000000..b78dc7c6d --- /dev/null +++ b/drivers/acpi/acpica/evglock.c @@ -0,0 +1,344 @@ +/****************************************************************************** + * + * Module Name: evglock - Global Lock support + * + *****************************************************************************/ + +/* + * Copyright (C) 2000 - 2015, Intel Corp. + * All rights reserved. + * + * 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. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * NO WARRANTY + * 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 MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES. + */ + +#include +#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 u32 acpi_ev_global_lock_handler(void *context); + +/******************************************************************************* + * + * FUNCTION: acpi_ev_init_global_lock_handler + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Install a handler for the global lock release event + * + ******************************************************************************/ + +acpi_status acpi_ev_init_global_lock_handler(void) +{ + acpi_status status; + + ACPI_FUNCTION_TRACE(ev_init_global_lock_handler); + + /* If Hardware Reduced flag is set, there is no global lock */ + + if (acpi_gbl_reduced_hardware) { + return_ACPI_STATUS(AE_OK); + } + + /* Attempt installation of the global lock handler */ + + status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL, + acpi_ev_global_lock_handler, + 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. + */ + acpi_gbl_global_lock_present = 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 = acpi_os_create_lock(&acpi_gbl_global_lock_pending_lock); + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); + } + + acpi_gbl_global_lock_pending = FALSE; + acpi_gbl_global_lock_present = TRUE; + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ev_remove_global_lock_handler + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Remove the handler for the Global Lock + * + ******************************************************************************/ + +acpi_status acpi_ev_remove_global_lock_handler(void) +{ + acpi_status status; + + ACPI_FUNCTION_TRACE(ev_remove_global_lock_handler); + + acpi_gbl_global_lock_present = FALSE; + status = acpi_remove_fixed_event_handler(ACPI_EVENT_GLOBAL, + acpi_ev_global_lock_handler); + + acpi_os_delete_lock(acpi_gbl_global_lock_pending_lock); + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ev_global_lock_handler + * + * 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 u32 acpi_ev_global_lock_handler(void *context) +{ + acpi_status status; + acpi_cpu_flags flags; + + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); + + /* + * 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 (!acpi_gbl_global_lock_pending) { + goto cleanup_and_exit; + } + + /* + * Send a unit to the global lock semaphore. The actual acquisition + * of the global lock will be performed by the waiting thread. + */ + status = acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, 1); + if (ACPI_FAILURE(status)) { + ACPI_ERROR((AE_INFO, "Could not signal Global Lock semaphore")); + } + + acpi_gbl_global_lock_pending = FALSE; + +cleanup_and_exit: + + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags); + return (ACPI_INTERRUPT_HANDLED); +} + +/****************************************************************************** + * + * FUNCTION: acpi_ev_acquire_global_lock + * + * 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 acpi_ev_acquire_global_lock(u16 timeout) +{ + acpi_cpu_flags flags; + acpi_status status; + u8 acquired = FALSE; + + ACPI_FUNCTION_TRACE(ev_acquire_global_lock); + + /* + * Only one thread can acquire the GL at a time, the global_lock_mutex + * enforces this. This interface releases the interpreter if we must wait. + */ + status = + acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex->mutex. + os_mutex, 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 acpi_acquire_global_lock interfaces. The + * handle is therefore updated on the first acquire from a given thread + * regardless of where the acquisition request originated. + */ + acpi_gbl_global_lock_handle++; + if (acpi_gbl_global_lock_handle == 0) { + acpi_gbl_global_lock_handle = 1; + } + + /* + * Make sure that a global lock actually exists. If not, just + * treat the lock as a standard mutex. + */ + if (!acpi_gbl_global_lock_present) { + acpi_gbl_global_lock_acquired = TRUE; + return_ACPI_STATUS(AE_OK); + } + + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); + + do { + + /* Attempt to acquire the actual hardware lock */ + + ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_FACS, acquired); + if (acquired) { + acpi_gbl_global_lock_acquired = 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. + */ + acpi_gbl_global_lock_pending = TRUE; + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, 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 = + acpi_ex_system_wait_semaphore + (acpi_gbl_global_lock_semaphore, ACPI_WAIT_FOREVER); + + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); + + } while (ACPI_SUCCESS(status)); + + acpi_gbl_global_lock_pending = FALSE; + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags); + + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ev_release_global_lock + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Releases ownership of the Global Lock. + * + ******************************************************************************/ + +acpi_status acpi_ev_release_global_lock(void) +{ + u8 pending = FALSE; + acpi_status status = AE_OK; + + ACPI_FUNCTION_TRACE(ev_release_global_lock); + + /* Lock must be already acquired */ + + if (!acpi_gbl_global_lock_acquired) { + ACPI_WARNING((AE_INFO, + "Cannot release the ACPI Global Lock, it has not been acquired")); + return_ACPI_STATUS(AE_NOT_ACQUIRED); + } + + if (acpi_gbl_global_lock_present) { + + /* Allow any thread to release the lock */ + + ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_FACS, pending); + + /* + * If the pending bit was set, we must write GBL_RLS to the control + * register + */ + if (pending) { + status = + acpi_write_bit_register + (ACPI_BITREG_GLOBAL_LOCK_RELEASE, + ACPI_ENABLE_EVENT); + } + + ACPI_DEBUG_PRINT((ACPI_DB_EXEC, + "Released hardware Global Lock\n")); + } + + acpi_gbl_global_lock_acquired = FALSE; + + /* Release the local GL mutex */ + + acpi_os_release_mutex(acpi_gbl_global_lock_mutex->mutex.os_mutex); + return_ACPI_STATUS(status); +} + +#endif /* !ACPI_REDUCED_HARDWARE */ -- cgit v1.2.3-54-g00ecf