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1
2/******************************************************************************
3 *
4 * Module Name: hwvalid - I/O request validation
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2011, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include "accommon.h"
47
48#define _COMPONENT ACPI_HARDWARE
49ACPI_MODULE_NAME("hwvalid")
50
51/* Local prototypes */
52static acpi_status
53acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width);
54
55/*
56 * Protected I/O ports. Some ports are always illegal, and some are
57 * conditionally illegal. This table must remain ordered by port address.
58 *
59 * The table is used to implement the Microsoft port access rules that
60 * first appeared in Windows XP. Some ports are always illegal, and some
61 * ports are only illegal if the BIOS calls _OSI with a win_xP string or
62 * later (meaning that the BIOS itelf is post-XP.)
63 *
64 * This provides ACPICA with the desired port protections and
65 * Microsoft compatibility.
66 *
67 * Description of port entries:
68 * DMA: DMA controller
69 * PIC0: Programmable Interrupt Controller (8259_a)
70 * PIT1: System Timer 1
71 * PIT2: System Timer 2 failsafe
72 * RTC: Real-time clock
73 * CMOS: Extended CMOS
74 * DMA1: DMA 1 page registers
75 * DMA1L: DMA 1 Ch 0 low page
76 * DMA2: DMA 2 page registers
77 * DMA2L: DMA 2 low page refresh
78 * ARBC: Arbitration control
79 * SETUP: Reserved system board setup
80 * POS: POS channel select
81 * PIC1: Cascaded PIC
82 * IDMA: ISA DMA
83 * ELCR: PIC edge/level registers
84 * PCI: PCI configuration space
85 */
86static const struct acpi_port_info acpi_protected_ports[] = {
87 {"DMA", 0x0000, 0x000F, ACPI_OSI_WIN_XP},
88 {"PIC0", 0x0020, 0x0021, ACPI_ALWAYS_ILLEGAL},
89 {"PIT1", 0x0040, 0x0043, ACPI_OSI_WIN_XP},
90 {"PIT2", 0x0048, 0x004B, ACPI_OSI_WIN_XP},
91 {"RTC", 0x0070, 0x0071, ACPI_OSI_WIN_XP},
92 {"CMOS", 0x0074, 0x0076, ACPI_OSI_WIN_XP},
93 {"DMA1", 0x0081, 0x0083, ACPI_OSI_WIN_XP},
94 {"DMA1L", 0x0087, 0x0087, ACPI_OSI_WIN_XP},
95 {"DMA2", 0x0089, 0x008B, ACPI_OSI_WIN_XP},
96 {"DMA2L", 0x008F, 0x008F, ACPI_OSI_WIN_XP},
97 {"ARBC", 0x0090, 0x0091, ACPI_OSI_WIN_XP},
98 {"SETUP", 0x0093, 0x0094, ACPI_OSI_WIN_XP},
99 {"POS", 0x0096, 0x0097, ACPI_OSI_WIN_XP},
100 {"PIC1", 0x00A0, 0x00A1, ACPI_ALWAYS_ILLEGAL},
101 {"IDMA", 0x00C0, 0x00DF, ACPI_OSI_WIN_XP},
102 {"ELCR", 0x04D0, 0x04D1, ACPI_ALWAYS_ILLEGAL},
103 {"PCI", 0x0CF8, 0x0CFF, ACPI_OSI_WIN_XP}
104};
105
106#define ACPI_PORT_INFO_ENTRIES ACPI_ARRAY_LENGTH (acpi_protected_ports)
107
108/******************************************************************************
109 *
110 * FUNCTION: acpi_hw_validate_io_request
111 *
112 * PARAMETERS: Address Address of I/O port/register
113 * bit_width Number of bits (8,16,32)
114 *
115 * RETURN: Status
116 *
117 * DESCRIPTION: Validates an I/O request (address/length). Certain ports are
118 * always illegal and some ports are only illegal depending on
119 * the requests the BIOS AML code makes to the predefined
120 * _OSI method.
121 *
122 ******************************************************************************/
123
124static acpi_status
125acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
126{
127 u32 i;
128 u32 byte_width;
129 acpi_io_address last_address;
130 const struct acpi_port_info *port_info;
131
132 ACPI_FUNCTION_TRACE(hw_validate_io_request);
133
134 /* Supported widths are 8/16/32 */
135
136 if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
137 return AE_BAD_PARAMETER;
138 }
139
140 port_info = acpi_protected_ports;
141 byte_width = ACPI_DIV_8(bit_width);
142 last_address = address + byte_width - 1;
143
144 ACPI_DEBUG_PRINT((ACPI_DB_IO, "Address %p LastAddress %p Length %X",
145 ACPI_CAST_PTR(void, address), ACPI_CAST_PTR(void,
146 last_address),
147 byte_width));
148
149 /* Maximum 16-bit address in I/O space */
150
151 if (last_address > ACPI_UINT16_MAX) {
152 ACPI_ERROR((AE_INFO,
153 "Illegal I/O port address/length above 64K: %p/0x%X",
154 ACPI_CAST_PTR(void, address), byte_width));
155 return_ACPI_STATUS(AE_LIMIT);
156 }
157
158 /* Exit if requested address is not within the protected port table */
159
160 if (address > acpi_protected_ports[ACPI_PORT_INFO_ENTRIES - 1].end) {
161 return_ACPI_STATUS(AE_OK);
162 }
163
164 /* Check request against the list of protected I/O ports */
165
166 for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, port_info++) {
167 /*
168 * Check if the requested address range will write to a reserved
169 * port. Four cases to consider:
170 *
171 * 1) Address range is contained completely in the port address range
172 * 2) Address range overlaps port range at the port range start
173 * 3) Address range overlaps port range at the port range end
174 * 4) Address range completely encompasses the port range
175 */
176 if ((address <= port_info->end)
177 && (last_address >= port_info->start)) {
178
179 /* Port illegality may depend on the _OSI calls made by the BIOS */
180
181 if (acpi_gbl_osi_data >= port_info->osi_dependency) {
182 ACPI_DEBUG_PRINT((ACPI_DB_IO,
183 "Denied AML access to port 0x%p/%X (%s 0x%.4X-0x%.4X)",
184 ACPI_CAST_PTR(void, address),
185 byte_width, port_info->name,
186 port_info->start,
187 port_info->end));
188
189 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
190 }
191 }
192
193 /* Finished if address range ends before the end of this port */
194
195 if (last_address <= port_info->end) {
196 break;
197 }
198 }
199
200 return_ACPI_STATUS(AE_OK);
201}
202
203/******************************************************************************
204 *
205 * FUNCTION: acpi_hw_read_port
206 *
207 * PARAMETERS: Address Address of I/O port/register to read
208 * Value Where value is placed
209 * Width Number of bits
210 *
211 * RETURN: Status and value read from port
212 *
213 * DESCRIPTION: Read data from an I/O port or register. This is a front-end
214 * to acpi_os_read_port that performs validation on both the port
215 * address and the length.
216 *
217 *****************************************************************************/
218
219acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
220{
221 acpi_status status;
222 u32 one_byte;
223 u32 i;
224
225 /* Truncate address to 16 bits if requested */
226
227 if (acpi_gbl_truncate_io_addresses) {
228 address &= ACPI_UINT16_MAX;
229 }
230
231 /* Validate the entire request and perform the I/O */
232
233 status = acpi_hw_validate_io_request(address, width);
234 if (ACPI_SUCCESS(status)) {
235 status = acpi_os_read_port(address, value, width);
236 return status;
237 }
238
239 if (status != AE_AML_ILLEGAL_ADDRESS) {
240 return status;
241 }
242
243 /*
244 * There has been a protection violation within the request. Fall
245 * back to byte granularity port I/O and ignore the failing bytes.
246 * This provides Windows compatibility.
247 */
248 for (i = 0, *value = 0; i < width; i += 8) {
249
250 /* Validate and read one byte */
251
252 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
253 status = acpi_os_read_port(address, &one_byte, 8);
254 if (ACPI_FAILURE(status)) {
255 return status;
256 }
257
258 *value |= (one_byte << i);
259 }
260
261 address++;
262 }
263
264 return AE_OK;
265}
266
267/******************************************************************************
268 *
269 * FUNCTION: acpi_hw_write_port
270 *
271 * PARAMETERS: Address Address of I/O port/register to write
272 * Value Value to write
273 * Width Number of bits
274 *
275 * RETURN: Status
276 *
277 * DESCRIPTION: Write data to an I/O port or register. This is a front-end
278 * to acpi_os_write_port that performs validation on both the port
279 * address and the length.
280 *
281 *****************************************************************************/
282
283acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
284{
285 acpi_status status;
286 u32 i;
287
288 /* Truncate address to 16 bits if requested */
289
290 if (acpi_gbl_truncate_io_addresses) {
291 address &= ACPI_UINT16_MAX;
292 }
293
294 /* Validate the entire request and perform the I/O */
295
296 status = acpi_hw_validate_io_request(address, width);
297 if (ACPI_SUCCESS(status)) {
298 status = acpi_os_write_port(address, value, width);
299 return status;
300 }
301
302 if (status != AE_AML_ILLEGAL_ADDRESS) {
303 return status;
304 }
305
306 /*
307 * There has been a protection violation within the request. Fall
308 * back to byte granularity port I/O and ignore the failing bytes.
309 * This provides Windows compatibility.
310 */
311 for (i = 0; i < width; i += 8) {
312
313 /* Validate and write one byte */
314
315 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
316 status =
317 acpi_os_write_port(address, (value >> i) & 0xFF, 8);
318 if (ACPI_FAILURE(status)) {
319 return status;
320 }
321 }
322
323 address++;
324 }
325
326 return AE_OK;
327}
1
2/******************************************************************************
3 *
4 * Module Name: hwvalid - I/O request validation
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2012, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include "accommon.h"
47
48#define _COMPONENT ACPI_HARDWARE
49ACPI_MODULE_NAME("hwvalid")
50
51/* Local prototypes */
52static acpi_status
53acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width);
54
55/*
56 * Protected I/O ports. Some ports are always illegal, and some are
57 * conditionally illegal. This table must remain ordered by port address.
58 *
59 * The table is used to implement the Microsoft port access rules that
60 * first appeared in Windows XP. Some ports are always illegal, and some
61 * ports are only illegal if the BIOS calls _OSI with a win_xP string or
62 * later (meaning that the BIOS itelf is post-XP.)
63 *
64 * This provides ACPICA with the desired port protections and
65 * Microsoft compatibility.
66 *
67 * Description of port entries:
68 * DMA: DMA controller
69 * PIC0: Programmable Interrupt Controller (8259_a)
70 * PIT1: System Timer 1
71 * PIT2: System Timer 2 failsafe
72 * RTC: Real-time clock
73 * CMOS: Extended CMOS
74 * DMA1: DMA 1 page registers
75 * DMA1L: DMA 1 Ch 0 low page
76 * DMA2: DMA 2 page registers
77 * DMA2L: DMA 2 low page refresh
78 * ARBC: Arbitration control
79 * SETUP: Reserved system board setup
80 * POS: POS channel select
81 * PIC1: Cascaded PIC
82 * IDMA: ISA DMA
83 * ELCR: PIC edge/level registers
84 * PCI: PCI configuration space
85 */
86static const struct acpi_port_info acpi_protected_ports[] = {
87 {"DMA", 0x0000, 0x000F, ACPI_OSI_WIN_XP},
88 {"PIC0", 0x0020, 0x0021, ACPI_ALWAYS_ILLEGAL},
89 {"PIT1", 0x0040, 0x0043, ACPI_OSI_WIN_XP},
90 {"PIT2", 0x0048, 0x004B, ACPI_OSI_WIN_XP},
91 {"RTC", 0x0070, 0x0071, ACPI_OSI_WIN_XP},
92 {"CMOS", 0x0074, 0x0076, ACPI_OSI_WIN_XP},
93 {"DMA1", 0x0081, 0x0083, ACPI_OSI_WIN_XP},
94 {"DMA1L", 0x0087, 0x0087, ACPI_OSI_WIN_XP},
95 {"DMA2", 0x0089, 0x008B, ACPI_OSI_WIN_XP},
96 {"DMA2L", 0x008F, 0x008F, ACPI_OSI_WIN_XP},
97 {"ARBC", 0x0090, 0x0091, ACPI_OSI_WIN_XP},
98 {"SETUP", 0x0093, 0x0094, ACPI_OSI_WIN_XP},
99 {"POS", 0x0096, 0x0097, ACPI_OSI_WIN_XP},
100 {"PIC1", 0x00A0, 0x00A1, ACPI_ALWAYS_ILLEGAL},
101 {"IDMA", 0x00C0, 0x00DF, ACPI_OSI_WIN_XP},
102 {"ELCR", 0x04D0, 0x04D1, ACPI_ALWAYS_ILLEGAL},
103 {"PCI", 0x0CF8, 0x0CFF, ACPI_OSI_WIN_XP}
104};
105
106#define ACPI_PORT_INFO_ENTRIES ACPI_ARRAY_LENGTH (acpi_protected_ports)
107
108/******************************************************************************
109 *
110 * FUNCTION: acpi_hw_validate_io_request
111 *
112 * PARAMETERS: Address Address of I/O port/register
113 * bit_width Number of bits (8,16,32)
114 *
115 * RETURN: Status
116 *
117 * DESCRIPTION: Validates an I/O request (address/length). Certain ports are
118 * always illegal and some ports are only illegal depending on
119 * the requests the BIOS AML code makes to the predefined
120 * _OSI method.
121 *
122 ******************************************************************************/
123
124static acpi_status
125acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
126{
127 u32 i;
128 u32 byte_width;
129 acpi_io_address last_address;
130 const struct acpi_port_info *port_info;
131
132 ACPI_FUNCTION_TRACE(hw_validate_io_request);
133
134 /* Supported widths are 8/16/32 */
135
136 if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
137 ACPI_ERROR((AE_INFO,
138 "Bad BitWidth parameter: %8.8X", bit_width));
139 return AE_BAD_PARAMETER;
140 }
141
142 port_info = acpi_protected_ports;
143 byte_width = ACPI_DIV_8(bit_width);
144 last_address = address + byte_width - 1;
145
146 ACPI_DEBUG_PRINT((ACPI_DB_IO, "Address %p LastAddress %p Length %X",
147 ACPI_CAST_PTR(void, address), ACPI_CAST_PTR(void,
148 last_address),
149 byte_width));
150
151 /* Maximum 16-bit address in I/O space */
152
153 if (last_address > ACPI_UINT16_MAX) {
154 ACPI_ERROR((AE_INFO,
155 "Illegal I/O port address/length above 64K: %p/0x%X",
156 ACPI_CAST_PTR(void, address), byte_width));
157 return_ACPI_STATUS(AE_LIMIT);
158 }
159
160 /* Exit if requested address is not within the protected port table */
161
162 if (address > acpi_protected_ports[ACPI_PORT_INFO_ENTRIES - 1].end) {
163 return_ACPI_STATUS(AE_OK);
164 }
165
166 /* Check request against the list of protected I/O ports */
167
168 for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, port_info++) {
169 /*
170 * Check if the requested address range will write to a reserved
171 * port. Four cases to consider:
172 *
173 * 1) Address range is contained completely in the port address range
174 * 2) Address range overlaps port range at the port range start
175 * 3) Address range overlaps port range at the port range end
176 * 4) Address range completely encompasses the port range
177 */
178 if ((address <= port_info->end)
179 && (last_address >= port_info->start)) {
180
181 /* Port illegality may depend on the _OSI calls made by the BIOS */
182
183 if (acpi_gbl_osi_data >= port_info->osi_dependency) {
184 ACPI_DEBUG_PRINT((ACPI_DB_IO,
185 "Denied AML access to port 0x%p/%X (%s 0x%.4X-0x%.4X)",
186 ACPI_CAST_PTR(void, address),
187 byte_width, port_info->name,
188 port_info->start,
189 port_info->end));
190
191 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
192 }
193 }
194
195 /* Finished if address range ends before the end of this port */
196
197 if (last_address <= port_info->end) {
198 break;
199 }
200 }
201
202 return_ACPI_STATUS(AE_OK);
203}
204
205/******************************************************************************
206 *
207 * FUNCTION: acpi_hw_read_port
208 *
209 * PARAMETERS: Address Address of I/O port/register to read
210 * Value Where value is placed
211 * Width Number of bits
212 *
213 * RETURN: Status and value read from port
214 *
215 * DESCRIPTION: Read data from an I/O port or register. This is a front-end
216 * to acpi_os_read_port that performs validation on both the port
217 * address and the length.
218 *
219 *****************************************************************************/
220
221acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
222{
223 acpi_status status;
224 u32 one_byte;
225 u32 i;
226
227 /* Truncate address to 16 bits if requested */
228
229 if (acpi_gbl_truncate_io_addresses) {
230 address &= ACPI_UINT16_MAX;
231 }
232
233 /* Validate the entire request and perform the I/O */
234
235 status = acpi_hw_validate_io_request(address, width);
236 if (ACPI_SUCCESS(status)) {
237 status = acpi_os_read_port(address, value, width);
238 return status;
239 }
240
241 if (status != AE_AML_ILLEGAL_ADDRESS) {
242 return status;
243 }
244
245 /*
246 * There has been a protection violation within the request. Fall
247 * back to byte granularity port I/O and ignore the failing bytes.
248 * This provides Windows compatibility.
249 */
250 for (i = 0, *value = 0; i < width; i += 8) {
251
252 /* Validate and read one byte */
253
254 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
255 status = acpi_os_read_port(address, &one_byte, 8);
256 if (ACPI_FAILURE(status)) {
257 return status;
258 }
259
260 *value |= (one_byte << i);
261 }
262
263 address++;
264 }
265
266 return AE_OK;
267}
268
269/******************************************************************************
270 *
271 * FUNCTION: acpi_hw_write_port
272 *
273 * PARAMETERS: Address Address of I/O port/register to write
274 * Value Value to write
275 * Width Number of bits
276 *
277 * RETURN: Status
278 *
279 * DESCRIPTION: Write data to an I/O port or register. This is a front-end
280 * to acpi_os_write_port that performs validation on both the port
281 * address and the length.
282 *
283 *****************************************************************************/
284
285acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
286{
287 acpi_status status;
288 u32 i;
289
290 /* Truncate address to 16 bits if requested */
291
292 if (acpi_gbl_truncate_io_addresses) {
293 address &= ACPI_UINT16_MAX;
294 }
295
296 /* Validate the entire request and perform the I/O */
297
298 status = acpi_hw_validate_io_request(address, width);
299 if (ACPI_SUCCESS(status)) {
300 status = acpi_os_write_port(address, value, width);
301 return status;
302 }
303
304 if (status != AE_AML_ILLEGAL_ADDRESS) {
305 return status;
306 }
307
308 /*
309 * There has been a protection violation within the request. Fall
310 * back to byte granularity port I/O and ignore the failing bytes.
311 * This provides Windows compatibility.
312 */
313 for (i = 0; i < width; i += 8) {
314
315 /* Validate and write one byte */
316
317 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
318 status =
319 acpi_os_write_port(address, (value >> i) & 0xFF, 8);
320 if (ACPI_FAILURE(status)) {
321 return status;
322 }
323 }
324
325 address++;
326 }
327
328 return AE_OK;
329}