xref: /openbmc/linux/drivers/acpi/acpica/hwvalid.c (revision b627b4ed)
1 
2 /******************************************************************************
3  *
4  * Module Name: hwvalid - I/O request validation
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2009, 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
49 ACPI_MODULE_NAME("hwvalid")
50 
51 /* Local prototypes */
52 static acpi_status
53 acpi_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  */
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 	{"DMA1L", 0x0087, 0x0087, ACPI_OSI_WIN_XP},
94 	{"DMA2", 0x0089, 0x008B, ACPI_OSI_WIN_XP},
95 	{"DMA2L", 0x008F, 0x008F, ACPI_OSI_WIN_XP},
96 	{"ARBC", 0x0090, 0x0091, ACPI_OSI_WIN_XP},
97 	{"SETUP", 0x0093, 0x0094, ACPI_OSI_WIN_XP},
98 	{"POS", 0x0096, 0x0097, ACPI_OSI_WIN_XP},
99 	{"PIC1", 0x00A0, 0x00A1, ACPI_ALWAYS_ILLEGAL},
100 	{"IDMA", 0x00C0, 0x00DF, ACPI_OSI_WIN_XP},
101 	{"ELCR", 0x04D0, 0x04D1, ACPI_ALWAYS_ILLEGAL},
102 	{"PCI", 0x0CF8, 0x0CFF, ACPI_OSI_WIN_XP}
103 };
104 
105 #define ACPI_PORT_INFO_ENTRIES  ACPI_ARRAY_LENGTH (acpi_protected_ports)
106 
107 /******************************************************************************
108  *
109  * FUNCTION:    acpi_hw_validate_io_request
110  *
111  * PARAMETERS:  Address             Address of I/O port/register
112  *              bit_width           Number of bits (8,16,32)
113  *
114  * RETURN:      Status
115  *
116  * DESCRIPTION: Validates an I/O request (address/length). Certain ports are
117  *              always illegal and some ports are only illegal depending on
118  *              the requests the BIOS AML code makes to the predefined
119  *              _OSI method.
120  *
121  ******************************************************************************/
122 
123 static acpi_status
124 acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
125 {
126 	u32 i;
127 	u32 byte_width;
128 	acpi_io_address last_address;
129 	const struct acpi_port_info *port_info;
130 
131 	ACPI_FUNCTION_TRACE(hw_validate_io_request);
132 
133 	/* Supported widths are 8/16/32 */
134 
135 	if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
136 		return AE_BAD_PARAMETER;
137 	}
138 
139 	port_info = acpi_protected_ports;
140 	byte_width = ACPI_DIV_8(bit_width);
141 	last_address = address + byte_width - 1;
142 
143 	ACPI_DEBUG_PRINT((ACPI_DB_IO, "Address %p LastAddress %p Length %X",
144 			  ACPI_CAST_PTR(void, address), ACPI_CAST_PTR(void,
145 								      last_address),
146 			  byte_width));
147 
148 	/* Maximum 16-bit address in I/O space */
149 
150 	if (last_address > ACPI_UINT16_MAX) {
151 		ACPI_ERROR((AE_INFO,
152 			    "Illegal I/O port address/length above 64K: 0x%p/%X",
153 			    ACPI_CAST_PTR(void, address), byte_width));
154 		return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
155 	}
156 
157 	/* Exit if requested address is not within the protected port table */
158 
159 	if (address > acpi_protected_ports[ACPI_PORT_INFO_ENTRIES - 1].end) {
160 		return_ACPI_STATUS(AE_OK);
161 	}
162 
163 	/* Check request against the list of protected I/O ports */
164 
165 	for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, port_info++) {
166 		/*
167 		 * Check if the requested address range will write to a reserved
168 		 * port. Four cases to consider:
169 		 *
170 		 * 1) Address range is contained completely in the port address range
171 		 * 2) Address range overlaps port range at the port range start
172 		 * 3) Address range overlaps port range at the port range end
173 		 * 4) Address range completely encompasses the port range
174 		 */
175 		if ((address <= port_info->end)
176 		    && (last_address >= port_info->start)) {
177 
178 			/* Port illegality may depend on the _OSI calls made by the BIOS */
179 
180 			if (acpi_gbl_osi_data >= port_info->osi_dependency) {
181 				ACPI_ERROR((AE_INFO,
182 					    "Denied AML access to port 0x%p/%X (%s 0x%.4X-0x%.4X)",
183 					    ACPI_CAST_PTR(void, address),
184 					    byte_width, port_info->name,
185 					    port_info->start, port_info->end));
186 
187 				return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
188 			}
189 		}
190 
191 		/* Finished if address range ends before the end of this port */
192 
193 		if (last_address <= port_info->end) {
194 			break;
195 		}
196 	}
197 
198 	return_ACPI_STATUS(AE_OK);
199 }
200 
201 /******************************************************************************
202  *
203  * FUNCTION:    acpi_hw_read_port
204  *
205  * PARAMETERS:  Address             Address of I/O port/register to read
206  *              Value               Where value is placed
207  *              Width               Number of bits
208  *
209  * RETURN:      Value read from port
210  *
211  * DESCRIPTION: Read data from an I/O port or register. This is a front-end
212  *              to acpi_os_read_port that performs validation on both the port
213  *              address and the length.
214  *
215  *****************************************************************************/
216 
217 acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
218 {
219 	acpi_status status;
220 
221 	status = acpi_hw_validate_io_request(address, width);
222 	if (ACPI_FAILURE(status)) {
223 		return status;
224 	}
225 
226 	status = acpi_os_read_port(address, value, width);
227 	return status;
228 }
229 
230 /******************************************************************************
231  *
232  * FUNCTION:    acpi_hw_write_port
233  *
234  * PARAMETERS:  Address             Address of I/O port/register to write
235  *              Value               Value to write
236  *              Width               Number of bits
237  *
238  * RETURN:      None
239  *
240  * DESCRIPTION: Write data to an I/O port or register. This is a front-end
241  *              to acpi_os_write_port that performs validation on both the port
242  *              address and the length.
243  *
244  *****************************************************************************/
245 
246 acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
247 {
248 	acpi_status status;
249 
250 	status = acpi_hw_validate_io_request(address, width);
251 	if (ACPI_FAILURE(status)) {
252 		return status;
253 	}
254 
255 	status = acpi_os_write_port(address, value, width);
256 	return status;
257 }
258