{
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"));
}
}
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.
*/
if (acquired) {
/* Got the lock, now wake all threads waiting for it */
+
acpi_gbl_global_lock_acquired = TRUE;
acpi_ev_global_lock_thread(context);
}
*
* 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_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) {
/* 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);
}
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);
}
#include <acpi/acpi.h>
#include <acpi/acinterp.h>
+#include <acpi/acevents.h>
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME("exmutex")
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
- /* Sanity check -- we must have a valid thread ID */
+ /* Sanity check: we must have a valid thread ID */
if (!walk_state->thread) {
ACPI_ERROR((AE_INFO,
/* Support for multiple acquires by the owning thread */
if (obj_desc->mutex.owner_thread) {
-
- /* Special case for Global Lock, allow all threads */
-
- if ((obj_desc->mutex.owner_thread->thread_id ==
- walk_state->thread->thread_id) ||
- (obj_desc->mutex.os_mutex == ACPI_GLOBAL_LOCK)) {
+ if (obj_desc->mutex.owner_thread->thread_id ==
+ walk_state->thread->thread_id) {
/*
- * The mutex is already owned by this thread,
- * just increment the acquisition depth
+ * The mutex is already owned by this thread, just increment the
+ * acquisition depth
*/
obj_desc->mutex.acquisition_depth++;
return_ACPI_STATUS(AE_OK);
}
}
- /* Acquire the mutex, wait if necessary */
+ /* Acquire the mutex, wait if necessary. Special case for Global Lock */
+
+ if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
+ status =
+ acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
+ } else {
+ status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
+ (u16) time_desc->integer.
+ value);
+ }
- status = acpi_ex_system_acquire_mutex(time_desc, obj_desc);
if (ACPI_FAILURE(status)) {
/* Includes failure from a timeout on time_desc */
/* Link the mutex to the current thread for force-unlock at method exit */
acpi_ex_link_mutex(obj_desc, walk_state->thread);
-
return_ACPI_STATUS(AE_OK);
}
acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
- acpi_status status;
+ acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE(ex_release_mutex);
return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
}
- /* Sanity check -- we must have a valid thread ID */
+ /* Sanity check: we must have a valid thread ID */
if (!walk_state->thread) {
ACPI_ERROR((AE_INFO,
*/
if ((obj_desc->mutex.owner_thread->thread_id !=
walk_state->thread->thread_id)
- && (obj_desc->mutex.os_mutex != ACPI_GLOBAL_LOCK)) {
+ && (obj_desc->mutex.os_mutex != acpi_gbl_global_lock_mutex)) {
ACPI_ERROR((AE_INFO,
"Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
(unsigned long)walk_state->thread->thread_id,
}
/*
- * The sync level of the mutex must be less than or
- * equal to the current sync level
+ * The sync level of the mutex must be less than or equal to the current
+ * sync level
*/
if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
ACPI_ERROR((AE_INFO,
acpi_ex_unlink_mutex(obj_desc);
- /* Release the mutex */
+ /* Release the mutex, special case for Global Lock */
- status = acpi_ex_system_release_mutex(obj_desc);
+ if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
+ status = acpi_ev_release_global_lock();
+ } else {
+ acpi_os_release_mutex(obj_desc->mutex.os_mutex);
+ }
- /* Update the mutex and walk state, restore sync_level before acquire */
+ /* Update the mutex and restore sync_level */
obj_desc->mutex.owner_thread = NULL;
walk_state->thread->current_sync_level =
void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
{
union acpi_operand_object *next = thread->acquired_mutex_list;
- union acpi_operand_object *this;
- acpi_status status;
+ union acpi_operand_object *obj_desc;
ACPI_FUNCTION_ENTRY();
/* Traverse the list of owned mutexes, releasing each one */
while (next) {
- this = next;
- next = this->mutex.next;
+ obj_desc = next;
+ next = obj_desc->mutex.next;
+
+ obj_desc->mutex.prev = NULL;
+ obj_desc->mutex.next = NULL;
+ obj_desc->mutex.acquisition_depth = 1;
+
+ /* Release the mutex, special case for Global Lock */
- this->mutex.acquisition_depth = 1;
- this->mutex.prev = NULL;
- this->mutex.next = NULL;
+ if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
- /* Release the mutex */
+ /* Ignore errors */
- status = acpi_ex_system_release_mutex(this);
- if (ACPI_FAILURE(status)) {
- continue;
+ (void)acpi_ev_release_global_lock();
+ } else {
+ acpi_os_release_mutex(obj_desc->mutex.os_mutex);
}
/* Mark mutex unowned */
- this->mutex.owner_thread = NULL;
+ obj_desc->mutex.owner_thread = NULL;
/* Update Thread sync_level (Last mutex is the important one) */
- thread->current_sync_level = this->mutex.original_sync_level;
+ thread->current_sync_level =
+ obj_desc->mutex.original_sync_level;
}
}
return (status);
}
-/*******************************************************************************
- *
- * FUNCTION: acpi_ex_system_acquire_mutex
- *
- * PARAMETERS: time_desc - Maximum time to wait for the mutex
- * obj_desc - The object descriptor for this op
- *
- * RETURN: Status
- *
- * DESCRIPTION: Provides an access point to perform synchronization operations
- * within the AML. This function will cause a lock to be generated
- * for the Mutex pointed to by obj_desc.
- *
- ******************************************************************************/
-
-acpi_status
-acpi_ex_system_acquire_mutex(union acpi_operand_object * time_desc,
- union acpi_operand_object * obj_desc)
-{
- acpi_status status = AE_OK;
-
- ACPI_FUNCTION_TRACE_PTR(ex_system_acquire_mutex, obj_desc);
-
- if (!obj_desc) {
- return_ACPI_STATUS(AE_BAD_PARAMETER);
- }
-
- /* Support for the _GL_ Mutex object -- go get the global lock */
-
- if (obj_desc->mutex.os_mutex == ACPI_GLOBAL_LOCK) {
- status =
- acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
- return_ACPI_STATUS(status);
- }
-
- status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
- (u16) time_desc->integer.value);
- return_ACPI_STATUS(status);
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_ex_system_release_mutex
- *
- * PARAMETERS: obj_desc - The object descriptor for this op
- *
- * RETURN: Status
- *
- * DESCRIPTION: Provides an access point to perform synchronization operations
- * within the AML. This operation is a request to release a
- * previously acquired Mutex. If the Mutex variable is set then
- * it will be decremented.
- *
- ******************************************************************************/
-
-acpi_status acpi_ex_system_release_mutex(union acpi_operand_object *obj_desc)
-{
- acpi_status status = AE_OK;
-
- ACPI_FUNCTION_TRACE(ex_system_release_mutex);
-
- if (!obj_desc) {
- return_ACPI_STATUS(AE_BAD_PARAMETER);
- }
-
- /* Support for the _GL_ Mutex object -- release the global lock */
-
- if (obj_desc->mutex.os_mutex == ACPI_GLOBAL_LOCK) {
- status = acpi_ev_release_global_lock();
- return_ACPI_STATUS(status);
- }
-
- acpi_os_release_mutex(obj_desc->mutex.os_mutex);
- return_ACPI_STATUS(AE_OK);
-}
-
/*******************************************************************************
*
* FUNCTION: acpi_ex_system_signal_event
*
******************************************************************************/
-acpi_status acpi_ex_system_signal_event(union acpi_operand_object *obj_desc)
+acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
{
acpi_status status = AE_OK;
obj_desc->mutex.sync_level =
(u8) (ACPI_TO_INTEGER(val) - 1);
- if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
-
- /* Create a counting semaphore for the global lock */
+ /* Create a mutex */
+
+ status =
+ acpi_os_create_mutex(&obj_desc->mutex.
+ os_mutex);
+ if (ACPI_FAILURE(status)) {
+ acpi_ut_remove_reference(obj_desc);
+ goto unlock_and_exit;
+ }
- status =
- acpi_os_create_semaphore
- (ACPI_NO_UNIT_LIMIT, 1,
- &acpi_gbl_global_lock_semaphore);
- if (ACPI_FAILURE(status)) {
- acpi_ut_remove_reference
- (obj_desc);
- goto unlock_and_exit;
- }
+ /* Special case for ACPI Global Lock */
- /* Mark this mutex as very special */
+ if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
+ acpi_gbl_global_lock_mutex =
+ obj_desc->mutex.os_mutex;
- obj_desc->mutex.os_mutex =
- ACPI_GLOBAL_LOCK;
- } else {
- /* Create a mutex */
+ /* Create additional counting semaphore for global lock */
status =
- acpi_os_create_mutex(&obj_desc->
- mutex.
- os_mutex);
+ acpi_os_create_semaphore(1, 1,
+ &acpi_gbl_global_lock_semaphore);
if (ACPI_FAILURE(status)) {
acpi_ut_remove_reference
(obj_desc);
"***** Mutex %p, OS Mutex %p\n",
object, object->mutex.os_mutex));
- if (object->mutex.os_mutex != ACPI_GLOBAL_LOCK) {
- acpi_ex_unlink_mutex(object);
- acpi_os_delete_mutex(object->mutex.os_mutex);
- } else {
- /* Global Lock "mutex" is actually a counting semaphore */
+ if (object->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
+
+ /* Global Lock has extra semaphore */
(void)
acpi_os_delete_semaphore
(acpi_gbl_global_lock_semaphore);
acpi_gbl_global_lock_semaphore = NULL;
+
+ acpi_os_delete_mutex(object->mutex.os_mutex);
+ acpi_gbl_global_lock_mutex = NULL;
+ } else {
+ acpi_ex_unlink_mutex(object);
+ acpi_os_delete_mutex(object->mutex.os_mutex);
}
break;
/* Global Lock support */
acpi_gbl_global_lock_semaphore = NULL;
+ acpi_gbl_global_lock_mutex = NULL;
acpi_gbl_global_lock_acquired = FALSE;
- acpi_gbl_global_lock_thread_count = 0;
acpi_gbl_global_lock_handle = 0;
/* Miscellaneous variables */
/*
* Global lock semaphore works in conjunction with the actual HW global lock
*/
+ACPI_EXTERN acpi_mutex acpi_gbl_global_lock_mutex;
ACPI_EXTERN acpi_semaphore acpi_gbl_global_lock_semaphore;
/*
/* Misc */
-ACPI_EXTERN u32 acpi_gbl_global_lock_thread_count;
ACPI_EXTERN u32 acpi_gbl_original_mode;
ACPI_EXTERN u32 acpi_gbl_rsdp_original_location;
ACPI_EXTERN u32 acpi_gbl_ns_lookup_count;
acpi_status acpi_ex_system_do_stall(u32 time);
-acpi_status
-acpi_ex_system_acquire_mutex(union acpi_operand_object *time,
- union acpi_operand_object *obj_desc);
-
-acpi_status acpi_ex_system_release_mutex(union acpi_operand_object *obj_desc);
-
acpi_status acpi_ex_system_signal_event(union acpi_operand_object *obj_desc);
acpi_status
#define ACPI_SERIALIZED 0xFF
typedef u32 acpi_mutex_handle;
-#define ACPI_GLOBAL_LOCK (acpi_semaphore) (-1)
/* Total number of aml opcodes defined */
projects / linux-2.6 / commitdiff