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[linux-2.6/lguest.git] / drivers / acpi / acpica / hwvalid.c
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2 /******************************************************************************
4 * Module Name: hwvalid - I/O request validation
6 *****************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2009, Intel Corp.
10 * All rights reserved.
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.
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24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
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.
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
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42 * POSSIBILITY OF SUCH DAMAGES.
45 #include <acpi/acpi.h>
46 #include "accommon.h"
48 #define _COMPONENT ACPI_HARDWARE
49 ACPI_MODULE_NAME("hwvalid")
51 /* Local prototypes */
52 static acpi_status
53 acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width);
56 * Protected I/O ports. Some ports are always illegal, and some are
57 * conditionally illegal. This table must remain ordered by port address.
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.)
64 * This provides ACPICA with the desired port protections and
65 * Microsoft compatibility.
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
86 static 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}
106 #define ACPI_PORT_INFO_ENTRIES ACPI_ARRAY_LENGTH (acpi_protected_ports)
108 /******************************************************************************
110 * FUNCTION: acpi_hw_validate_io_request
112 * PARAMETERS: Address Address of I/O port/register
113 * bit_width Number of bits (8,16,32)
115 * RETURN: Status
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.
122 ******************************************************************************/
124 static acpi_status
125 acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
127 u32 i;
128 u32 byte_width;
129 acpi_io_address last_address;
130 const struct acpi_port_info *port_info;
132 ACPI_FUNCTION_TRACE(hw_validate_io_request);
134 /* Supported widths are 8/16/32 */
136 if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
137 return AE_BAD_PARAMETER;
140 port_info = acpi_protected_ports;
141 byte_width = ACPI_DIV_8(bit_width);
142 last_address = address + byte_width - 1;
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));
149 /* Maximum 16-bit address in I/O space */
151 if (last_address > ACPI_UINT16_MAX) {
152 ACPI_ERROR((AE_INFO,
153 "Illegal I/O port address/length above 64K: 0x%p/%X",
154 ACPI_CAST_PTR(void, address), byte_width));
155 return_ACPI_STATUS(AE_LIMIT);
158 /* Exit if requested address is not within the protected port table */
160 if (address > acpi_protected_ports[ACPI_PORT_INFO_ENTRIES - 1].end) {
161 return_ACPI_STATUS(AE_OK);
164 /* Check request against the list of protected I/O ports */
166 for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, port_info++) {
168 * Check if the requested address range will write to a reserved
169 * port. Four cases to consider:
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
176 if ((address <= port_info->end)
177 && (last_address >= port_info->start)) {
179 /* Port illegality may depend on the _OSI calls made by the BIOS */
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));
189 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
193 /* Finished if address range ends before the end of this port */
195 if (last_address <= port_info->end) {
196 break;
200 return_ACPI_STATUS(AE_OK);
203 /******************************************************************************
205 * FUNCTION: acpi_hw_read_port
207 * PARAMETERS: Address Address of I/O port/register to read
208 * Value Where value is placed
209 * Width Number of bits
211 * RETURN: Status and value read from port
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.
217 *****************************************************************************/
219 acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
221 acpi_status status;
222 u32 one_byte;
223 u32 i;
225 /* Validate the entire request and perform the I/O */
227 status = acpi_hw_validate_io_request(address, width);
228 if (ACPI_SUCCESS(status)) {
229 status = acpi_os_read_port(address, value, width);
230 return status;
233 if (status != AE_AML_ILLEGAL_ADDRESS) {
234 return status;
238 * There has been a protection violation within the request. Fall
239 * back to byte granularity port I/O and ignore the failing bytes.
240 * This provides Windows compatibility.
242 for (i = 0, *value = 0; i < width; i += 8) {
244 /* Validate and read one byte */
246 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
247 status = acpi_os_read_port(address, &one_byte, 8);
248 if (ACPI_FAILURE(status)) {
249 return status;
252 *value |= (one_byte << i);
255 address++;
258 return AE_OK;
261 /******************************************************************************
263 * FUNCTION: acpi_hw_write_port
265 * PARAMETERS: Address Address of I/O port/register to write
266 * Value Value to write
267 * Width Number of bits
269 * RETURN: Status
271 * DESCRIPTION: Write data to an I/O port or register. This is a front-end
272 * to acpi_os_write_port that performs validation on both the port
273 * address and the length.
275 *****************************************************************************/
277 acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
279 acpi_status status;
280 u32 i;
282 /* Validate the entire request and perform the I/O */
284 status = acpi_hw_validate_io_request(address, width);
285 if (ACPI_SUCCESS(status)) {
286 status = acpi_os_write_port(address, value, width);
287 return status;
290 if (status != AE_AML_ILLEGAL_ADDRESS) {
291 return status;
295 * There has been a protection violation within the request. Fall
296 * back to byte granularity port I/O and ignore the failing bytes.
297 * This provides Windows compatibility.
299 for (i = 0; i < width; i += 8) {
301 /* Validate and write one byte */
303 if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
304 status =
305 acpi_os_write_port(address, (value >> i) & 0xFF, 8);
306 if (ACPI_FAILURE(status)) {
307 return status;
311 address++;
314 return AE_OK;