patch-2.4.6 linux/drivers/acpi/executer/exmutex.c

• Lines: 282
• Date: Wed Jun 20 17:47:40 2001
• Orig file: v2.4.5/linux/drivers/acpi/executer/exmutex.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/drivers/acpi/executer/exmutex.c linux/drivers/acpi/executer/exmutex.c
@@ -0,0 +1,281 @@
+
+/******************************************************************************
+ *
+ * Module Name: exmutex - ASL Mutex Acquire/Release functions
+ *              $Revision: 5 $
+ *
+ *****************************************************************************/
+
+/*
+ *  Copyright (C) 2000, 2001 R. Byron Moore
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+#include "acpi.h"
+#include "acinterp.h"
+#include "acnamesp.h"
+#include "achware.h"
+#include "acevents.h"
+
+#define _COMPONENT          ACPI_EXECUTER
+	 MODULE_NAME         ("exmutex")
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    Acpi_ex_unlink_mutex
+ *
+ * PARAMETERS:  *Obj_desc           - The mutex to be unlinked
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Remove a mutex from the "Acquired_mutex" list
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_unlink_mutex (
+	ACPI_OPERAND_OBJECT     *obj_desc)
+{
+
+	if (obj_desc->mutex.next) {
+		(obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
+	}
+	if (obj_desc->mutex.prev) {
+		(obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
+	}
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    Acpi_ex_link_mutex
+ *
+ * PARAMETERS:  *Obj_desc           - The mutex to be linked
+ *              *List_head          - head of the "Acquired_mutex" list
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Add a mutex to the "Acquired_mutex" list for this walk
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_link_mutex (
+	ACPI_OPERAND_OBJECT     *obj_desc,
+	ACPI_OPERAND_OBJECT     *list_head)
+{
+
+	/* This object will be the first object in the list */
+
+	obj_desc->mutex.prev = list_head;
+	obj_desc->mutex.next = list_head->mutex.next;
+
+	/* Update old first object to point back to this object */
+
+	if (list_head->mutex.next) {
+		(list_head->mutex.next)->mutex.prev = obj_desc;
+	}
+
+	/* Update list head */
+
+	list_head->mutex.next = obj_desc;
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    Acpi_ex_acquire_mutex
+ *
+ * PARAMETERS:  *Time_desc          - The 'time to delay' object descriptor
+ *              *Obj_desc           - The object descriptor for this op
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Acquire an AML mutex
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_acquire_mutex (
+	ACPI_OPERAND_OBJECT     *time_desc,
+	ACPI_OPERAND_OBJECT     *obj_desc,
+	ACPI_WALK_STATE         *walk_state)
+{
+	ACPI_STATUS             status;
+
+
+	if (!obj_desc) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	/*
+	 * Current Sync must be less than or equal to the sync level of the
+	 * mutex.  This mechanism provides some deadlock prevention
+	 */
+	if (walk_state->current_sync_level > obj_desc->mutex.sync_level) {
+		return (AE_AML_MUTEX_ORDER);
+	}
+
+	/*
+	 * If the mutex is already owned by this thread,
+	 * just increment the acquisition depth
+	 */
+	if (obj_desc->mutex.owner == walk_state) {
+		obj_desc->mutex.acquisition_depth++;
+		return (AE_OK);
+	}
+
+	/* Acquire the mutex, wait if necessary */
+
+	status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);
+	if (ACPI_FAILURE (status)) {
+		/* Includes failure from a timeout on Time_desc */
+
+		return (status);
+	}
+
+	/* Have the mutex, update mutex and walk info */
+
+	obj_desc->mutex.owner = walk_state;
+	obj_desc->mutex.acquisition_depth = 1;
+	walk_state->current_sync_level = obj_desc->mutex.sync_level;
+
+	/* Link the mutex to the walk state for force-unlock at method exit */
+
+	acpi_ex_link_mutex (obj_desc, (ACPI_OPERAND_OBJECT *)
+			 &(walk_state->walk_list->acquired_mutex_list));
+
+	return (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    Acpi_ex_release_mutex
+ *
+ * PARAMETERS:  *Obj_desc           - The object descriptor for this op
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Release a previously acquired Mutex.
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_release_mutex (
+	ACPI_OPERAND_OBJECT     *obj_desc,
+	ACPI_WALK_STATE         *walk_state)
+{
+	ACPI_STATUS             status;
+
+
+	if (!obj_desc) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	/*  The mutex must have been previously acquired in order to release it */
+
+	if (!obj_desc->mutex.owner) {
+		return (AE_AML_MUTEX_NOT_ACQUIRED);
+	}
+
+	/* The Mutex is owned, but this thread must be the owner */
+
+	if (obj_desc->mutex.owner != walk_state) {
+		return (AE_AML_NOT_OWNER);
+	}
+
+	/*
+	 * 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->current_sync_level) {
+		return (AE_AML_MUTEX_ORDER);
+	}
+
+	/*
+	 * Match multiple Acquires with multiple Releases
+	 */
+	obj_desc->mutex.acquisition_depth--;
+	if (obj_desc->mutex.acquisition_depth != 0) {
+		/* Just decrement the depth and return */
+
+		return (AE_OK);
+	}
+
+
+	/* Release the mutex */
+
+	status = acpi_ex_system_release_mutex (obj_desc);
+
+	/* Update the mutex and walk state */
+
+	obj_desc->mutex.owner = NULL;
+	walk_state->current_sync_level = obj_desc->mutex.sync_level;
+
+	/* Unlink the mutex from the owner's list */
+
+	acpi_ex_unlink_mutex (obj_desc);
+
+	return (status);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    Acpi_ex_release_all_mutexes
+ *
+ * PARAMETERS:  *Mutex_list           - Head of the mutex list
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Release all mutexes in the list
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_release_all_mutexes (
+	ACPI_OPERAND_OBJECT     *list_head)
+{
+	ACPI_OPERAND_OBJECT     *next = list_head->mutex.next;
+	ACPI_OPERAND_OBJECT     *this;
+
+
+	/*
+	 * Traverse the list of owned mutexes, releasing each one.
+	 */
+	while (next) {
+		this = next;
+		next = this->mutex.next;
+
+		/* Mark mutex un-owned */
+
+		this->mutex.owner = NULL;
+		this->mutex.prev = NULL;
+		this->mutex.next = NULL;
+		this->mutex.acquisition_depth = 0;
+
+		 /* Release the mutex */
+
+		acpi_ex_system_release_mutex (this);
+	}
+
+	return (AE_OK);
+}
+
+