From c81da66608d65dab04730582dfdfcdcab779e2fe Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:18 +0300 Subject: ACPICA: Delete recursive feature of ACPI Global Lock Completed a new design and implementation for the ACPI Global Lock support. On the OS side, the global lock is now treated as a standard AML mutex. Previously, multiple OS threads could acquire the global lock simultaneously, but this could cause the BIOS to be starved by the lock in cases such as the Embedded Controller driver, where there is a tight coupling between the OS and the BIOS. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 113 ++++++++++++++++++++++--------------------- 1 file changed, 59 insertions(+), 54 deletions(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index bf63edc..f82b81c 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -298,19 +298,13 @@ static void ACPI_SYSTEM_XFACE acpi_ev_global_lock_thread(void *context) { acpi_status status; - /* Signal threads that are waiting for the lock */ + /* Signal the thread that is waiting for the lock */ - if (acpi_gbl_global_lock_thread_count) { + /* Send a unit to the semaphore */ - /* Send sufficient units to the semaphore */ - - status = - acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, - acpi_gbl_global_lock_thread_count); - if (ACPI_FAILURE(status)) { - ACPI_ERROR((AE_INFO, - "Could not signal Global Lock semaphore")); - } + 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")); } } @@ -333,7 +327,8 @@ static u32 acpi_ev_global_lock_handler(void *context) u8 acquired = FALSE; /* - * Attempt to get the lock + * Attempt to get the lock. + * * If we don't get it now, it will be marked pending and we will * take another interrupt when it becomes free. */ @@ -341,6 +336,7 @@ static u32 acpi_ev_global_lock_handler(void *context) if (acquired) { /* Got the lock, now wake all threads waiting for it */ + acpi_gbl_global_lock_acquired = TRUE; acpi_ev_global_lock_thread(context); } @@ -399,6 +395,16 @@ acpi_status acpi_ev_init_global_lock_handler(void) * * 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) @@ -408,27 +414,25 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) ACPI_FUNCTION_TRACE(ev_acquire_global_lock); -#ifndef ACPI_APPLICATION - /* Make sure that we actually have a global lock */ - - if (!acpi_gbl_global_lock_present) { - return_ACPI_STATUS(AE_NO_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, timeout); + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); } -#endif - - /* One more thread wants the global lock */ - - acpi_gbl_global_lock_thread_count++; /* - * If we (OS side vs. BIOS side) have the hardware lock already, - * we are done + * Make sure that a global lock actually exists. If not, just treat + * the lock as a standard mutex. */ - if (acpi_gbl_global_lock_acquired) { + if (!acpi_gbl_global_lock_present) { + acpi_gbl_global_lock_acquired = TRUE; return_ACPI_STATUS(AE_OK); } - /* We must acquire the actual hardware lock */ + /* Attempt to acquire the actual hardware lock */ ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, acquired); if (acquired) { @@ -436,25 +440,24 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) /* We got the lock */ ACPI_DEBUG_PRINT((ACPI_DB_EXEC, - "Acquired the HW Global Lock\n")); + "Acquired hardware Global Lock\n")); acpi_gbl_global_lock_acquired = TRUE; return_ACPI_STATUS(AE_OK); } /* - * Did not get the lock. The pending bit was set above, and we must now + * Did not get the lock. The pending bit was set above, and we must now * wait until we get the global lock released interrupt. */ - ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Waiting for the HW Global Lock\n")); + ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Waiting for hardware Global Lock\n")); /* - * Acquire the global lock semaphore first. - * Since this wait will block, we must release the interpreter + * 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, - timeout); + status = acpi_ex_system_wait_semaphore(acpi_gbl_global_lock_semaphore, + ACPI_WAIT_FOREVER); return_ACPI_STATUS(status); } @@ -477,38 +480,40 @@ acpi_status acpi_ev_release_global_lock(void) ACPI_FUNCTION_TRACE(ev_release_global_lock); - if (!acpi_gbl_global_lock_thread_count) { + /* Lock must be acquired */ + + if (!acpi_gbl_global_lock_acquired) { ACPI_WARNING((AE_INFO, - "Cannot release HW Global Lock, it has not been acquired")); + "Cannot release the ACPI Global Lock, it has not been acquired")); return_ACPI_STATUS(AE_NOT_ACQUIRED); } - /* One fewer thread has the global lock */ + if (acpi_gbl_global_lock_present) { - acpi_gbl_global_lock_thread_count--; - if (acpi_gbl_global_lock_thread_count) { + /* Allow any thread to release the lock */ - /* There are still some threads holding the lock, cannot release */ + ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, + pending); - return_ACPI_STATUS(AE_OK); + /* + * If the pending bit was set, we must write GBL_RLS to the control + * register + */ + if (pending) { + status = + acpi_set_register(ACPI_BITREG_GLOBAL_LOCK_RELEASE, + 1, ACPI_MTX_LOCK); + } + + ACPI_DEBUG_PRINT((ACPI_DB_EXEC, + "Released hardware Global Lock\n")); } - /* - * No more threads holding lock, we can do the actual hardware - * release - */ - ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, pending); acpi_gbl_global_lock_acquired = FALSE; - /* - * If the pending bit was set, we must write GBL_RLS to the control - * register - */ - if (pending) { - status = acpi_set_register(ACPI_BITREG_GLOBAL_LOCK_RELEASE, - 1, ACPI_MTX_LOCK); - } + /* Release the local GL mutex */ + acpi_os_release_mutex(acpi_gbl_global_lock_mutex); return_ACPI_STATUS(status); } -- cgit v1.1 From a72d47563bce9542b9a83521a4e8175076278ee9 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:18 +0300 Subject: ACPICA: Release global lock from interrupt handler The ACPI Global Lock interrupt handler no longer queues the execution of a separate thread to signal the global lock semaphore. Instead, the semaphore is signaled directly from the interrupt handler. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 50 +++++++++++++------------------------------- 1 file changed, 15 insertions(+), 35 deletions(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index f82b81c..00f33ed 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -67,8 +67,6 @@ static const char *acpi_notify_value_names[] = { static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context); -static void ACPI_SYSTEM_XFACE acpi_ev_global_lock_thread(void *context); - static u32 acpi_ev_global_lock_handler(void *context); /******************************************************************************* @@ -282,43 +280,19 @@ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context) /******************************************************************************* * - * FUNCTION: acpi_ev_global_lock_thread - * - * PARAMETERS: Context - From thread interface, not used - * - * RETURN: None - * - * DESCRIPTION: Invoked by SCI interrupt handler upon acquisition of the - * Global Lock. Simply signal all threads that are waiting - * for the lock. - * - ******************************************************************************/ - -static void ACPI_SYSTEM_XFACE acpi_ev_global_lock_thread(void *context) -{ - acpi_status status; - - /* Signal the thread that is waiting for the lock */ - - /* Send a unit to the semaphore */ - - 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")); - } -} - -/******************************************************************************* - * * FUNCTION: acpi_ev_global_lock_handler * * PARAMETERS: Context - From thread interface, not used * - * RETURN: ACPI_INTERRUPT_HANDLED or ACPI_INTERRUPT_NOT_HANDLED + * RETURN: ACPI_INTERRUPT_HANDLED * * DESCRIPTION: Invoked directly from the SCI handler when a global lock - * release interrupt occurs. Grab the global lock and queue - * the global lock thread for execution + * release interrupt occurs. Attempt to acquire the global lock, + * if successful, signal the thread waiting for the lock. + * + * NOTE: Assumes that the semaphore can be signaled from interrupt level. If + * this is not possible for some reason, a separate thread will have to be + * scheduled to do this. * ******************************************************************************/ @@ -338,7 +312,13 @@ static u32 acpi_ev_global_lock_handler(void *context) /* Got the lock, now wake all threads waiting for it */ acpi_gbl_global_lock_acquired = TRUE; - acpi_ev_global_lock_thread(context); + /* Send a unit to the semaphore */ + + if (ACPI_FAILURE(acpi_os_signal_semaphore( + acpi_gbl_global_lock_semaphore, 1))) { + ACPI_ERROR((AE_INFO, + "Could not signal Global Lock semaphore")); + } } return (ACPI_INTERRUPT_HANDLED); @@ -480,7 +460,7 @@ acpi_status acpi_ev_release_global_lock(void) ACPI_FUNCTION_TRACE(ev_release_global_lock); - /* Lock must be acquired */ + /* Lock must be already acquired */ if (!acpi_gbl_global_lock_acquired) { ACPI_WARNING((AE_INFO, -- cgit v1.1 From f3d2e7865c816258c699ff965768e46b50d536d3 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:18 +0300 Subject: ACPICA: Implement simplified Table Manager The Table Manager component has been completely redesigned and reimplemented. The new design is much simpler, and reduces the overall code and data size of the kernel-resident ACPICA by approximately 5%. Also, it is now possible to obtain the ACPI tables very early during kernel initialization, even before dynamic memory management is initialized. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index 00f33ed..21449f3 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -63,6 +63,10 @@ static const char *acpi_notify_value_names[] = { }; #endif +/* Pointer to FACS needed for the Global Lock */ + +static struct acpi_table_facs *facs = NULL; + /* Local prototypes */ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context); @@ -306,7 +310,7 @@ static u32 acpi_ev_global_lock_handler(void *context) * If we don't get it now, it will be marked pending and we will * take another interrupt when it becomes free. */ - ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, acquired); + ACPI_ACQUIRE_GLOBAL_LOCK(facs, acquired); if (acquired) { /* Got the lock, now wake all threads waiting for it */ @@ -342,6 +346,13 @@ acpi_status acpi_ev_init_global_lock_handler(void) ACPI_FUNCTION_TRACE(ev_init_global_lock_handler); + status = + acpi_get_table(ACPI_SIG_FACS, 0, + (struct acpi_table_header **)&facs); + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); + } + acpi_gbl_global_lock_present = TRUE; status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL, acpi_ev_global_lock_handler, @@ -414,7 +425,7 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) /* Attempt to acquire the actual hardware lock */ - ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, acquired); + ACPI_ACQUIRE_GLOBAL_LOCK(facs, acquired); if (acquired) { /* We got the lock */ @@ -438,6 +449,7 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) */ status = acpi_ex_system_wait_semaphore(acpi_gbl_global_lock_semaphore, ACPI_WAIT_FOREVER); + return_ACPI_STATUS(status); } @@ -472,8 +484,7 @@ acpi_status acpi_ev_release_global_lock(void) /* Allow any thread to release the lock */ - ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, - pending); + ACPI_RELEASE_GLOBAL_LOCK(facs, pending); /* * If the pending bit was set, we must write GBL_RLS to the control -- cgit v1.1 From d8c71b6d3b21cf21ad775e1cf6da95bf87bd5ad4 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:21 +0300 Subject: ACPICA: Remove obsolete Flags parameter. Remove flags parameter for acpi_{get,set}_register(). It is no longer necessary now that these functions use a spinlock for mutual exclusion. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index 21449f3..3bacede 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -493,7 +493,7 @@ acpi_status acpi_ev_release_global_lock(void) if (pending) { status = acpi_set_register(ACPI_BITREG_GLOBAL_LOCK_RELEASE, - 1, ACPI_MTX_LOCK); + 1); } ACPI_DEBUG_PRINT((ACPI_DB_EXEC, -- cgit v1.1 From 310a7f7fee489b7dadd27b0d8487bd0ce66281e7 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:21 +0300 Subject: ACPICA: Use faster ByIndex interface to get FACS Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index 3bacede..545f934 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -347,8 +347,8 @@ acpi_status acpi_ev_init_global_lock_handler(void) ACPI_FUNCTION_TRACE(ev_init_global_lock_handler); status = - acpi_get_table(ACPI_SIG_FACS, 0, - (struct acpi_table_header **)&facs); + acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS, + (struct acpi_table_header **)&facs); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } -- cgit v1.1 From 8876016bb384044a59c1e2ddcad4cf41b06344b9 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:22 +0300 Subject: ACPICA: Remove global lock handler on AcpiTerminate. Added AcpiEvRemoveGlobalLockHandler Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index 545f934..db16300 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -73,6 +73,8 @@ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context); static u32 acpi_ev_global_lock_handler(void *context); +static acpi_status acpi_ev_remove_global_lock_handler(void); + /******************************************************************************* * * FUNCTION: acpi_ev_is_notify_object @@ -376,6 +378,31 @@ acpi_status acpi_ev_init_global_lock_handler(void) return_ACPI_STATUS(status); } +/******************************************************************************* + * + * FUNCTION: acpi_ev_remove_global_lock_handler + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Remove the handler for the Global Lock + * + ******************************************************************************/ + +static 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); + + return_ACPI_STATUS(status); +} + /****************************************************************************** * * FUNCTION: acpi_ev_acquire_global_lock @@ -554,6 +581,12 @@ void acpi_ev_terminate(void) if (ACPI_FAILURE(status)) { ACPI_ERROR((AE_INFO, "Could not remove SCI handler")); } + + status = acpi_ev_remove_global_lock_handler(); + if (ACPI_FAILURE(status)) { + ACPI_ERROR((AE_INFO, + "Could not remove Global Lock handler")); + } } /* Deallocate all handler objects installed within GPE info structs */ -- cgit v1.1 From 6c9deb7201d96733dcd1b4cc44e99232308db359 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Fri, 2 Feb 2007 19:48:24 +0300 Subject: ACPICA: Update copyright to 2007. Added 2007 copyright to all module headers and signons. This affects virtually every file in the ACPICA core subsystem, iASL compiler, and the utilities. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/events/evmisc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/acpi/events/evmisc.c') diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c index db16300..1b784ffe 100644 --- a/drivers/acpi/events/evmisc.c +++ b/drivers/acpi/events/evmisc.c @@ -5,7 +5,7 @@ *****************************************************************************/ /* - * Copyright (C) 2000 - 2006, R. Byron Moore + * Copyright (C) 2000 - 2007, R. Byron Moore * All rights reserved. * * Redistribution and use in source and binary forms, with or without -- cgit v1.1