[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / acpica / utosi.c

/******************************************************************************
 *
 * Module Name: utosi - Support for the _OSI predefined control method
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, 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 <acpi/acpi.h>
#include "accommon.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utosi")

/*
 * Strings supported by the _OSI predefined control method (which is
 * implemented internally within this module.)
 *
 * March 2009: Removed "Linux" as this host no longer wants to respond true
 * for this string. Basically, the only safe OS strings are windows-related
 * and in many or most cases represent the only test path within the
 * BIOS-provided ASL code.
 *
 * The last element of each entry is used to track the newest version of
 * Windows that the BIOS has requested.
 */
static struct acpi_interface_info acpi_default_supported_interfaces[] = {
	/* Operating System Vendor Strings */

	{"Windows 2000", NULL, 0, ACPI_OSI_WIN_2000},	/* Windows 2000 */
	{"Windows 2001", NULL, 0, ACPI_OSI_WIN_XP},	/* Windows XP */
	{"Windows 2001 SP1", NULL, 0, ACPI_OSI_WIN_XP_SP1},	/* Windows XP SP1 */
	{"Windows 2001.1", NULL, 0, ACPI_OSI_WINSRV_2003},	/* Windows Server 2003 */
	{"Windows 2001 SP2", NULL, 0, ACPI_OSI_WIN_XP_SP2},	/* Windows XP SP2 */
	{"Windows 2001.1 SP1", NULL, 0, ACPI_OSI_WINSRV_2003_SP1},	/* Windows Server 2003 SP1 - Added 03/2006 */
	{"Windows 2006", NULL, 0, ACPI_OSI_WIN_VISTA},	/* Windows Vista - Added 03/2006 */
	{"Windows 2006.1", NULL, 0, ACPI_OSI_WINSRV_2008},	/* Windows Server 2008 - Added 09/2009 */
	{"Windows 2006 SP1", NULL, 0, ACPI_OSI_WIN_VISTA_SP1},	/* Windows Vista SP1 - Added 09/2009 */
	{"Windows 2006 SP2", NULL, 0, ACPI_OSI_WIN_VISTA_SP2},	/* Windows Vista SP2 - Added 09/2010 */
	{"Windows 2009", NULL, 0, ACPI_OSI_WIN_7},	/* Windows 7 and Server 2008 R2 - Added 09/2009 */

	/* Feature Group Strings */

	{"Extended Address Space Descriptor", NULL, 0, 0}

	/*
	 * All "optional" feature group strings (features that are implemented
	 * by the host) should be dynamically added by the host via
	 * acpi_install_interface and should not be manually added here.
	 *
	 * Examples of optional feature group strings:
	 *
	 * "Module Device"
	 * "Processor Device"
	 * "3.0 Thermal Model"
	 * "3.0 _SCP Extensions"
	 * "Processor Aggregator Device"
	 */
};

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_initialize_interfaces
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize the global _OSI supported interfaces list
 *
 ******************************************************************************/

acpi_status acpi_ut_initialize_interfaces(void)
{
	u32 i;

	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
	acpi_gbl_supported_interfaces = acpi_default_supported_interfaces;

	/* Link the static list of supported interfaces */

	for (i = 0;
	     i < (ACPI_ARRAY_LENGTH(acpi_default_supported_interfaces) - 1);
	     i++) {
		acpi_default_supported_interfaces[i].next =
		    &acpi_default_supported_interfaces[(acpi_size) i + 1];
	}

	acpi_os_release_mutex(acpi_gbl_osi_mutex);
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_interface_terminate
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Delete all interfaces in the global list. Sets
 *              acpi_gbl_supported_interfaces to NULL.
 *
 ******************************************************************************/

void acpi_ut_interface_terminate(void)
{
	struct acpi_interface_info *next_interface;

	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
	next_interface = acpi_gbl_supported_interfaces;

	while (next_interface) {
		acpi_gbl_supported_interfaces = next_interface->next;

		/* Only interfaces added at runtime can be freed */

		if (next_interface->flags & ACPI_OSI_DYNAMIC) {
			ACPI_FREE(next_interface->name);
			ACPI_FREE(next_interface);
		}

		next_interface = acpi_gbl_supported_interfaces;
	}

	acpi_os_release_mutex(acpi_gbl_osi_mutex);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_install_interface
 *
 * PARAMETERS:  interface_name      - The interface to install
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install the interface into the global interface list.
 *              Caller MUST hold acpi_gbl_osi_mutex
 *
 ******************************************************************************/

acpi_status acpi_ut_install_interface(acpi_string interface_name)
{
	struct acpi_interface_info *interface_info;

	/* Allocate info block and space for the name string */

	interface_info =
	    ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_interface_info));
	if (!interface_info) {
		return (AE_NO_MEMORY);
	}

	interface_info->name =
	    ACPI_ALLOCATE_ZEROED(ACPI_STRLEN(interface_name) + 1);
	if (!interface_info->name) {
		ACPI_FREE(interface_info);
		return (AE_NO_MEMORY);
	}

	/* Initialize new info and insert at the head of the global list */

	ACPI_STRCPY(interface_info->name, interface_name);
	interface_info->flags = ACPI_OSI_DYNAMIC;
	interface_info->next = acpi_gbl_supported_interfaces;

	acpi_gbl_supported_interfaces = interface_info;
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_remove_interface
 *
 * PARAMETERS:  interface_name      - The interface to remove
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove the interface from the global interface list.
 *              Caller MUST hold acpi_gbl_osi_mutex
 *
 ******************************************************************************/

acpi_status acpi_ut_remove_interface(acpi_string interface_name)
{
	struct acpi_interface_info *previous_interface;
	struct acpi_interface_info *next_interface;

	previous_interface = next_interface = acpi_gbl_supported_interfaces;
	while (next_interface) {
		if (!ACPI_STRCMP(interface_name, next_interface->name)) {

			/* Found: name is in either the static list or was added at runtime */

			if (next_interface->flags & ACPI_OSI_DYNAMIC) {

				/* Interface was added dynamically, remove and free it */

				if (previous_interface == next_interface) {
					acpi_gbl_supported_interfaces =
					    next_interface->next;
				} else {
					previous_interface->next =
					    next_interface->next;
				}

				ACPI_FREE(next_interface->name);
				ACPI_FREE(next_interface);
			} else {
				/*
				 * Interface is in static list. If marked invalid, then it
				 * does not actually exist. Else, mark it invalid.
				 */
				if (next_interface->flags & ACPI_OSI_INVALID) {
					return (AE_NOT_EXIST);
				}

				next_interface->flags |= ACPI_OSI_INVALID;
			}

			return (AE_OK);
		}

		previous_interface = next_interface;
		next_interface = next_interface->next;
	}

	/* Interface was not found */

	return (AE_NOT_EXIST);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_interface
 *
 * PARAMETERS:  interface_name      - The interface to find
 *
 * RETURN:      struct acpi_interface_info if found. NULL if not found.
 *
 * DESCRIPTION: Search for the specified interface name in the global list.
 *              Caller MUST hold acpi_gbl_osi_mutex
 *
 ******************************************************************************/

struct acpi_interface_info *acpi_ut_get_interface(acpi_string interface_name)
{
	struct acpi_interface_info *next_interface;

	next_interface = acpi_gbl_supported_interfaces;
	while (next_interface) {
		if (!ACPI_STRCMP(interface_name, next_interface->name)) {
			return (next_interface);
		}

		next_interface = next_interface->next;
	}

	return (NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_osi_implementation
 *
 * PARAMETERS:  walk_state          - Current walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Implementation of the _OSI predefined control method. When
 *              an invocation of _OSI is encountered in the system AML,
 *              control is transferred to this function.
 *
 ******************************************************************************/

acpi_status acpi_ut_osi_implementation(struct acpi_walk_state * walk_state)
{
	union acpi_operand_object *string_desc;
	union acpi_operand_object *return_desc;
	struct acpi_interface_info *interface_info;
	acpi_interface_handler interface_handler;
	u32 return_value;

	ACPI_FUNCTION_TRACE(ut_osi_implementation);

	/* Validate the string input argument (from the AML caller) */

	string_desc = walk_state->arguments[0].object;
	if (!string_desc || (string_desc->common.type != ACPI_TYPE_STRING)) {
		return_ACPI_STATUS(AE_TYPE);
	}

	/* Create a return object */

	return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
	if (!return_desc) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Default return value is 0, NOT SUPPORTED */

	return_value = 0;
	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);

	/* Lookup the interface in the global _OSI list */

	interface_info = acpi_ut_get_interface(string_desc->string.pointer);
	if (interface_info && !(interface_info->flags & ACPI_OSI_INVALID)) {
		/*
		 * The interface is supported.
		 * Update the osi_data if necessary. We keep track of the latest
		 * version of Windows that has been requested by the BIOS.
		 */
		if (interface_info->value > acpi_gbl_osi_data) {
			acpi_gbl_osi_data = interface_info->value;
		}

		return_value = ACPI_UINT32_MAX;
	}

	acpi_os_release_mutex(acpi_gbl_osi_mutex);

	/*
	 * Invoke an optional _OSI interface handler. The host OS may wish
	 * to do some interface-specific handling. For example, warn about
	 * certain interfaces or override the true/false support value.
	 */
	interface_handler = acpi_gbl_interface_handler;
	if (interface_handler) {
		return_value =
		    interface_handler(string_desc->string.pointer,
				      return_value);
	}

	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
			      "ACPI: BIOS _OSI(\"%s\") is %ssupported\n",
			      string_desc->string.pointer,
			      return_value == 0 ? "not " : ""));

	/* Complete the return object */

	return_desc->integer.value = return_value;
	walk_state->return_desc = return_desc;
	return_ACPI_STATUS(AE_OK);
}
Commit	Line	Data
b0ed7a91 LM	1	/******************************************************************************
	2	*
	3	* Module Name: utosi - Support for the _OSI predefined control method
	4	*
	5	*****************************************************************************/
	6
	7	/*
77848130	8	* Copyright (C) 2000 - 2012, Intel Corp.
b0ed7a91 LM	9	* All rights reserved.
	10	*
	11	* Redistribution and use in source and binary forms, with or without
	12	* modification, are permitted provided that the following conditions
	13	* are met:
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions, and the following disclaimer,
	16	* without modification.
	17	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	18	* substantially similar to the "NO WARRANTY" disclaimer below
	19	* ("Disclaimer") and any redistribution must be conditioned upon
	20	* including a substantially similar Disclaimer requirement for further
	21	* binary redistribution.
	22	* 3. Neither the names of the above-listed copyright holders nor the names
	23	* of any contributors may be used to endorse or promote products derived
	24	* from this software without specific prior written permission.
	25	*
	26	* Alternatively, this software may be distributed under the terms of the
	27	* GNU General Public License ("GPL") version 2 as published by the Free
	28	* Software Foundation.
	29	*
	30	* NO WARRANTY
	31	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	32	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	33	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	34	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	35	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	36	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	37	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	38	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	39	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	40	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	41	* POSSIBILITY OF SUCH DAMAGES.
	42	*/
	43
	44	#include <acpi/acpi.h>
	45	#include "accommon.h"
	46
	47	#define _COMPONENT ACPI_UTILITIES
	48	ACPI_MODULE_NAME("utosi")
	49
	50	/*
	51	* Strings supported by the _OSI predefined control method (which is
	52	* implemented internally within this module.)
	53	*
	54	* March 2009: Removed "Linux" as this host no longer wants to respond true
	55	* for this string. Basically, the only safe OS strings are windows-related
	56	* and in many or most cases represent the only test path within the
	57	* BIOS-provided ASL code.
	58	*
	59	* The last element of each entry is used to track the newest version of
	60	* Windows that the BIOS has requested.
	61	*/
	62	static struct acpi_interface_info acpi_default_supported_interfaces[] = {
	63	/* Operating System Vendor Strings */
	64
	65	{"Windows 2000", NULL, 0, ACPI_OSI_WIN_2000}, /* Windows 2000 */
	66	{"Windows 2001", NULL, 0, ACPI_OSI_WIN_XP}, /* Windows XP */
	67	{"Windows 2001 SP1", NULL, 0, ACPI_OSI_WIN_XP_SP1}, /* Windows XP SP1 */
	68	{"Windows 2001.1", NULL, 0, ACPI_OSI_WINSRV_2003}, /* Windows Server 2003 */
	69	{"Windows 2001 SP2", NULL, 0, ACPI_OSI_WIN_XP_SP2}, /* Windows XP SP2 */
	70	{"Windows 2001.1 SP1", NULL, 0, ACPI_OSI_WINSRV_2003_SP1}, /* Windows Server 2003 SP1 - Added 03/2006 */
	71	{"Windows 2006", NULL, 0, ACPI_OSI_WIN_VISTA}, /* Windows Vista - Added 03/2006 */
	72	{"Windows 2006.1", NULL, 0, ACPI_OSI_WINSRV_2008}, /* Windows Server 2008 - Added 09/2009 */
73	{"Windows 2006 SP1", NULL, 0, ACPI_OSI_WIN_VISTA_SP1}, /* Windows Vista SP1 - Added 09/2009 */
23ebbf07	74	{"Windows 2006 SP2", NULL, 0, ACPI_OSI_WIN_VISTA_SP2}, /* Windows Vista SP2 - Added 09/2010 */
b0ed7a91 LM	75	{"Windows 2009", NULL, 0, ACPI_OSI_WIN_7}, /* Windows 7 and Server 2008 R2 - Added 09/2009 */
	76
	77	/* Feature Group Strings */
	78
	79	{"Extended Address Space Descriptor", NULL, 0, 0}
	80
	81	/*
	82	* All "optional" feature group strings (features that are implemented
	83	* by the host) should be dynamically added by the host via
	84	* acpi_install_interface and should not be manually added here.
	85	*
	86	* Examples of optional feature group strings:
	87	*
	88	* "Module Device"
	89	* "Processor Device"
	90	* "3.0 Thermal Model"
	91	* "3.0 _SCP Extensions"
	92	* "Processor Aggregator Device"
	93	*/
	94	};
	95
	96	/*******************************************************************************
	97	*
	98	* FUNCTION: acpi_ut_initialize_interfaces
	99	*
	100	* PARAMETERS: None
	101	*
	102	* RETURN: Status
	103	*
	104	* DESCRIPTION: Initialize the global _OSI supported interfaces list
	105	*
	106	******************************************************************************/
	107
	108	acpi_status acpi_ut_initialize_interfaces(void)
	109	{
	110	u32 i;
	111
	112	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
	113	acpi_gbl_supported_interfaces = acpi_default_supported_interfaces;
	114
	115	/* Link the static list of supported interfaces */
	116
	117	for (i = 0;
	118	i < (ACPI_ARRAY_LENGTH(acpi_default_supported_interfaces) - 1);
	119	i++) {
	120	acpi_default_supported_interfaces[i].next =
	121	&acpi_default_supported_interfaces[(acpi_size) i + 1];
	122	}
	123
	124	acpi_os_release_mutex(acpi_gbl_osi_mutex);
	125	return (AE_OK);
	126	}
	127
	128	/*******************************************************************************
	129	*
	130	* FUNCTION: acpi_ut_interface_terminate
	131	*
	132	* PARAMETERS: None
	133	*
	134	* RETURN: None
	135	*
	136	* DESCRIPTION: Delete all interfaces in the global list. Sets
	137	* acpi_gbl_supported_interfaces to NULL.
	138	*
139	******************************************************************************/
140
141	void acpi_ut_interface_terminate(void)
142	{
143	struct acpi_interface_info *next_interface;
144
145	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
146	next_interface = acpi_gbl_supported_interfaces;
147
148	while (next_interface) {
149	acpi_gbl_supported_interfaces = next_interface->next;
150
151	/* Only interfaces added at runtime can be freed */
152
153	if (next_interface->flags & ACPI_OSI_DYNAMIC) {
154	ACPI_FREE(next_interface->name);
155	ACPI_FREE(next_interface);
156	}
157
158	next_interface = acpi_gbl_supported_interfaces;
159	}
160
161	acpi_os_release_mutex(acpi_gbl_osi_mutex);
162	}
163
164	/*******************************************************************************
165	*
166	* FUNCTION: acpi_ut_install_interface
167	*
168	* PARAMETERS: interface_name - The interface to install
169	*
170	* RETURN: Status
171	*
172	* DESCRIPTION: Install the interface into the global interface list.
173	* Caller MUST hold acpi_gbl_osi_mutex
174	*
175	******************************************************************************/
176
177	acpi_status acpi_ut_install_interface(acpi_string interface_name)
178	{
179	struct acpi_interface_info *interface_info;
180
181	/* Allocate info block and space for the name string */
182
183	interface_info =
184	ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_interface_info));
185	if (!interface_info) {
186	return (AE_NO_MEMORY);
187	}
188
189	interface_info->name =
190	ACPI_ALLOCATE_ZEROED(ACPI_STRLEN(interface_name) + 1);
191	if (!interface_info->name) {
192	ACPI_FREE(interface_info);
193	return (AE_NO_MEMORY);
194	}
195
196	/* Initialize new info and insert at the head of the global list */
197
198	ACPI_STRCPY(interface_info->name, interface_name);
199	interface_info->flags = ACPI_OSI_DYNAMIC;
200	interface_info->next = acpi_gbl_supported_interfaces;
201
202	acpi_gbl_supported_interfaces = interface_info;
203	return (AE_OK);
204	}
205
206	/*******************************************************************************
207	*
208	* FUNCTION: acpi_ut_remove_interface
209	*
210	* PARAMETERS: interface_name - The interface to remove
211	*
212	* RETURN: Status
213	*
214	* DESCRIPTION: Remove the interface from the global interface list.
215	* Caller MUST hold acpi_gbl_osi_mutex
216	*
217	******************************************************************************/
218
219	acpi_status acpi_ut_remove_interface(acpi_string interface_name)
220	{
221	struct acpi_interface_info *previous_interface;
222	struct acpi_interface_info *next_interface;
223
224	previous_interface = next_interface = acpi_gbl_supported_interfaces;
225	while (next_interface) {
226	if (!ACPI_STRCMP(interface_name, next_interface->name)) {
227
228	/* Found: name is in either the static list or was added at runtime */
229
230	if (next_interface->flags & ACPI_OSI_DYNAMIC) {
231
232	/* Interface was added dynamically, remove and free it */
233
234	if (previous_interface == next_interface) {
235	acpi_gbl_supported_interfaces =
236	next_interface->next;
237	} else {
238	previous_interface->next =
239	next_interface->next;
240	}
241
242	ACPI_FREE(next_interface->name);
243	ACPI_FREE(next_interface);
244	} else {
245	/*
246	* Interface is in static list. If marked invalid, then it
247	* does not actually exist. Else, mark it invalid.
248	*/
249	if (next_interface->flags & ACPI_OSI_INVALID) {
250	return (AE_NOT_EXIST);
251	}
252
253	next_interface->flags \|= ACPI_OSI_INVALID;
254	}
255
256	return (AE_OK);
257	}
258
259	previous_interface = next_interface;
260	next_interface = next_interface->next;
261	}
262
263	/* Interface was not found */
264
265	return (AE_NOT_EXIST);
266	}
267
268	/*******************************************************************************
269	*
270	* FUNCTION: acpi_ut_get_interface
271	*
272	* PARAMETERS: interface_name - The interface to find
273	*
274	* RETURN: struct acpi_interface_info if found. NULL if not found.
275	*
276	* DESCRIPTION: Search for the specified interface name in the global list.
277	* Caller MUST hold acpi_gbl_osi_mutex
278	*
279	******************************************************************************/
280
281	struct acpi_interface_info *acpi_ut_get_interface(acpi_string interface_name)
282	{
283	struct acpi_interface_info *next_interface;
284
285	next_interface = acpi_gbl_supported_interfaces;
286	while (next_interface) {
287	if (!ACPI_STRCMP(interface_name, next_interface->name)) {
288	return (next_interface);
289	}
290
291	next_interface = next_interface->next;
292	}
293
294	return (NULL);
295	}
296
297	/*******************************************************************************
298	*
299	* FUNCTION: acpi_ut_osi_implementation
300	*
301	* PARAMETERS: walk_state - Current walk state
302	*
303	* RETURN: Status
304	*
305	* DESCRIPTION: Implementation of the _OSI predefined control method. When
306	* an invocation of _OSI is encountered in the system AML,
307	* control is transferred to this function.
308	*
309	******************************************************************************/
310
311	acpi_status acpi_ut_osi_implementation(struct acpi_walk_state * walk_state)
312	{
313	union acpi_operand_object *string_desc;
314	union acpi_operand_object *return_desc;
315	struct acpi_interface_info *interface_info;
316	acpi_interface_handler interface_handler;
317	u32 return_value;
318
319	ACPI_FUNCTION_TRACE(ut_osi_implementation);
320
321	/* Validate the string input argument (from the AML caller) */
322
323	string_desc = walk_state->arguments[0].object;
324	if (!string_desc \|\| (string_desc->common.type != ACPI_TYPE_STRING)) {
325	return_ACPI_STATUS(AE_TYPE);
326	}
327
328	/* Create a return object */
329
330	return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
331	if (!return_desc) {
332	return_ACPI_STATUS(AE_NO_MEMORY);
333	}
334
335	/* Default return value is 0, NOT SUPPORTED */
336
337	return_value = 0;
338	(void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
339
340	/* Lookup the interface in the global _OSI list */
341
342	interface_info = acpi_ut_get_interface(string_desc->string.pointer);
343	if (interface_info && !(interface_info->flags & ACPI_OSI_INVALID)) {
344	/*
345	* The interface is supported.
346	* Update the osi_data if necessary. We keep track of the latest
347	* version of Windows that has been requested by the BIOS.
348	*/
349	if (interface_info->value > acpi_gbl_osi_data) {
350	acpi_gbl_osi_data = interface_info->value;
351	}
352
353	return_value = ACPI_UINT32_MAX;
354	}
355
356	acpi_os_release_mutex(acpi_gbl_osi_mutex);
357
358	/*
359	* Invoke an optional _OSI interface handler. The host OS may wish
360	* to do some interface-specific handling. For example, warn about
361	* certain interfaces or override the true/false support value.
362	*/
363	interface_handler = acpi_gbl_interface_handler;
364	if (interface_handler) {
365	return_value =
366	interface_handler(string_desc->string.pointer,
367	return_value);
368	}
369
370	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
371	"ACPI: BIOS _OSI(\"%s\") is %ssupported\n",
372	string_desc->string.pointer,
373	return_value == 0 ? "not " : ""));
374
375	/* Complete the return object */
376
377	return_desc->integer.value = return_value;
378	walk_state->return_desc = return_desc;
379	return_ACPI_STATUS(AE_OK);
380	}