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1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: hwvalid - I/O request validation
5  *
6  * Copyright (C) 2000 - 2020, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 
13 #define _COMPONENT          ACPI_HARDWARE
14 ACPI_MODULE_NAME("hwvalid")
15 
16 /* Local prototypes */
17 static acpi_status
18 acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width);
19 
20 /*
21  * Protected I/O ports. Some ports are always illegal, and some are
22  * conditionally illegal. This table must remain ordered by port address.
23  *
24  * The table is used to implement the Microsoft port access rules that
25  * first appeared in Windows XP. Some ports are always illegal, and some
26  * ports are only illegal if the BIOS calls _OSI with nothing newer than
27  * the specific _OSI strings.
28  *
29  * This provides ACPICA with the desired port protections and
30  * Microsoft compatibility.
31  *
32  * Description of port entries:
33  *  DMA:   DMA controller
34  *  PIC0:  Programmable Interrupt Controller (8259A)
35  *  PIT1:  System Timer 1
36  *  PIT2:  System Timer 2 failsafe
37  *  RTC:   Real-time clock
38  *  CMOS:  Extended CMOS
39  *  DMA1:  DMA 1 page registers
40  *  DMA1L: DMA 1 Ch 0 low page
41  *  DMA2:  DMA 2 page registers
42  *  DMA2L: DMA 2 low page refresh
43  *  ARBC:  Arbitration control
44  *  SETUP: Reserved system board setup
45  *  POS:   POS channel select
46  *  PIC1:  Cascaded PIC
47  *  IDMA:  ISA DMA
48  *  ELCR:  PIC edge/level registers
49  *  PCI:   PCI configuration space
50  */
51 static const struct acpi_port_info acpi_protected_ports[] = {
52 	{"DMA", 0x0000, 0x000F, ACPI_OSI_WIN_XP},
53 	{"PIC0", 0x0020, 0x0021, ACPI_ALWAYS_ILLEGAL},
54 	{"PIT1", 0x0040, 0x0043, ACPI_OSI_WIN_XP},
55 	{"PIT2", 0x0048, 0x004B, ACPI_OSI_WIN_XP},
56 	{"RTC", 0x0070, 0x0071, ACPI_OSI_WIN_XP},
57 	{"CMOS", 0x0074, 0x0076, ACPI_OSI_WIN_XP},
58 	{"DMA1", 0x0081, 0x0083, ACPI_OSI_WIN_XP},
59 	{"DMA1L", 0x0087, 0x0087, ACPI_OSI_WIN_XP},
60 	{"DMA2", 0x0089, 0x008B, ACPI_OSI_WIN_XP},
61 	{"DMA2L", 0x008F, 0x008F, ACPI_OSI_WIN_XP},
62 	{"ARBC", 0x0090, 0x0091, ACPI_OSI_WIN_XP},
63 	{"SETUP", 0x0093, 0x0094, ACPI_OSI_WIN_XP},
64 	{"POS", 0x0096, 0x0097, ACPI_OSI_WIN_XP},
65 	{"PIC1", 0x00A0, 0x00A1, ACPI_ALWAYS_ILLEGAL},
66 	{"IDMA", 0x00C0, 0x00DF, ACPI_OSI_WIN_XP},
67 	{"ELCR", 0x04D0, 0x04D1, ACPI_ALWAYS_ILLEGAL},
68 	{"PCI", 0x0CF8, 0x0CFF, ACPI_OSI_WIN_XP}
69 };
70 
71 #define ACPI_PORT_INFO_ENTRIES      ACPI_ARRAY_LENGTH (acpi_protected_ports)
72 
73 /******************************************************************************
74  *
75  * FUNCTION:    acpi_hw_validate_io_request
76  *
77  * PARAMETERS:  Address             Address of I/O port/register
78  *              bit_width           Number of bits (8,16,32)
79  *
80  * RETURN:      Status
81  *
82  * DESCRIPTION: Validates an I/O request (address/length). Certain ports are
83  *              always illegal and some ports are only illegal depending on
84  *              the requests the BIOS AML code makes to the predefined
85  *              _OSI method.
86  *
87  ******************************************************************************/
88 
89 static acpi_status
acpi_hw_validate_io_request(acpi_io_address address,u32 bit_width)90 acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
91 {
92 	u32 i;
93 	u32 byte_width;
94 	acpi_io_address last_address;
95 	const struct acpi_port_info *port_info;
96 
97 	ACPI_FUNCTION_TRACE(hw_validate_io_request);
98 
99 	/* Supported widths are 8/16/32 */
100 
101 	if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
102 		ACPI_ERROR((AE_INFO,
103 			    "Bad BitWidth parameter: %8.8X", bit_width));
104 		return_ACPI_STATUS(AE_BAD_PARAMETER);
105 	}
106 
107 	port_info = acpi_protected_ports;
108 	byte_width = ACPI_DIV_8(bit_width);
109 	last_address = address + byte_width - 1;
110 
111 	ACPI_DEBUG_PRINT((ACPI_DB_IO,
112 			  "Address %8.8X%8.8X LastAddress %8.8X%8.8X Length %X",
113 			  ACPI_FORMAT_UINT64(address),
114 			  ACPI_FORMAT_UINT64(last_address), byte_width));
115 
116 	/* Maximum 16-bit address in I/O space */
117 
118 	if (last_address > ACPI_UINT16_MAX) {
119 		ACPI_ERROR((AE_INFO,
120 			    "Illegal I/O port address/length above 64K: %8.8X%8.8X/0x%X",
121 			    ACPI_FORMAT_UINT64(address), byte_width));
122 		return_ACPI_STATUS(AE_LIMIT);
123 	}
124 
125 	/* Exit if requested address is not within the protected port table */
126 
127 	if (address > acpi_protected_ports[ACPI_PORT_INFO_ENTRIES - 1].end) {
128 		return_ACPI_STATUS(AE_OK);
129 	}
130 
131 	/* Check request against the list of protected I/O ports */
132 
133 	for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, port_info++) {
134 		/*
135 		 * Check if the requested address range will write to a reserved
136 		 * port. There are four cases to consider:
137 		 *
138 		 * 1) Address range is contained completely in the port address range
139 		 * 2) Address range overlaps port range at the port range start
140 		 * 3) Address range overlaps port range at the port range end
141 		 * 4) Address range completely encompasses the port range
142 		 */
143 		if ((address <= port_info->end)
144 		    && (last_address >= port_info->start)) {
145 
146 			/* Port illegality may depend on the _OSI calls made by the BIOS */
147 
148 			if (port_info->osi_dependency == ACPI_ALWAYS_ILLEGAL ||
149 			    acpi_gbl_osi_data == port_info->osi_dependency) {
150 				ACPI_DEBUG_PRINT((ACPI_DB_VALUES,
151 						  "Denied AML access to port 0x%8.8X%8.8X/%X (%s 0x%.4X-0x%.4X)\n",
152 						  ACPI_FORMAT_UINT64(address),
153 						  byte_width, port_info->name,
154 						  port_info->start,
155 						  port_info->end));
156 
157 				return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
158 			}
159 		}
160 
161 		/* Finished if address range ends before the end of this port */
162 
163 		if (last_address <= port_info->end) {
164 			break;
165 		}
166 	}
167 
168 	return_ACPI_STATUS(AE_OK);
169 }
170 
171 /******************************************************************************
172  *
173  * FUNCTION:    acpi_hw_read_port
174  *
175  * PARAMETERS:  Address             Address of I/O port/register to read
176  *              Value               Where value (data) is returned
177  *              Width               Number of bits
178  *
179  * RETURN:      Status and value read from port
180  *
181  * DESCRIPTION: Read data from an I/O port or register. This is a front-end
182  *              to acpi_os_read_port that performs validation on both the port
183  *              address and the length.
184  *
185  *****************************************************************************/
186 
acpi_hw_read_port(acpi_io_address address,u32 * value,u32 width)187 acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
188 {
189 	acpi_status status;
190 	u32 one_byte;
191 	u32 i;
192 
193 	/* Truncate address to 16 bits if requested */
194 
195 	if (acpi_gbl_truncate_io_addresses) {
196 		address &= ACPI_UINT16_MAX;
197 	}
198 
199 	/* Validate the entire request and perform the I/O */
200 
201 	status = acpi_hw_validate_io_request(address, width);
202 	if (ACPI_SUCCESS(status)) {
203 		status = acpi_os_read_port(address, value, width);
204 		return (status);
205 	}
206 
207 	if (status != AE_AML_ILLEGAL_ADDRESS) {
208 		return (status);
209 	}
210 
211 	/*
212 	 * There has been a protection violation within the request. Fall
213 	 * back to byte granularity port I/O and ignore the failing bytes.
214 	 * This provides compatibility with other ACPI implementations.
215 	 */
216 	for (i = 0, *value = 0; i < width; i += 8) {
217 
218 		/* Validate and read one byte */
219 
220 		if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
221 			status = acpi_os_read_port(address, &one_byte, 8);
222 			if (ACPI_FAILURE(status)) {
223 				return (status);
224 			}
225 
226 			*value |= (one_byte << i);
227 		}
228 
229 		address++;
230 	}
231 
232 	return (AE_OK);
233 }
234 
235 /******************************************************************************
236  *
237  * FUNCTION:    acpi_hw_write_port
238  *
239  * PARAMETERS:  Address             Address of I/O port/register to write
240  *              Value               Value to write
241  *              Width               Number of bits
242  *
243  * RETURN:      Status
244  *
245  * DESCRIPTION: Write data to an I/O port or register. This is a front-end
246  *              to acpi_os_write_port that performs validation on both the port
247  *              address and the length.
248  *
249  *****************************************************************************/
250 
acpi_hw_write_port(acpi_io_address address,u32 value,u32 width)251 acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
252 {
253 	acpi_status status;
254 	u32 i;
255 
256 	/* Truncate address to 16 bits if requested */
257 
258 	if (acpi_gbl_truncate_io_addresses) {
259 		address &= ACPI_UINT16_MAX;
260 	}
261 
262 	/* Validate the entire request and perform the I/O */
263 
264 	status = acpi_hw_validate_io_request(address, width);
265 	if (ACPI_SUCCESS(status)) {
266 		status = acpi_os_write_port(address, value, width);
267 		return (status);
268 	}
269 
270 	if (status != AE_AML_ILLEGAL_ADDRESS) {
271 		return (status);
272 	}
273 
274 	/*
275 	 * There has been a protection violation within the request. Fall
276 	 * back to byte granularity port I/O and ignore the failing bytes.
277 	 * This provides compatibility with other ACPI implementations.
278 	 */
279 	for (i = 0; i < width; i += 8) {
280 
281 		/* Validate and write one byte */
282 
283 		if (acpi_hw_validate_io_request(address, 8) == AE_OK) {
284 			status =
285 			    acpi_os_write_port(address, (value >> i) & 0xFF, 8);
286 			if (ACPI_FAILURE(status)) {
287 				return (status);
288 			}
289 		}
290 
291 		address++;
292 	}
293 
294 	return (AE_OK);
295 }
296 
297 /******************************************************************************
298  *
299  * FUNCTION:    acpi_hw_validate_io_block
300  *
301  * PARAMETERS:  Address             Address of I/O port/register blobk
302  *              bit_width           Number of bits (8,16,32) in each register
303  *              count               Number of registers in the block
304  *
305  * RETURN:      Status
306  *
307  * DESCRIPTION: Validates a block of I/O ports/registers.
308  *
309  ******************************************************************************/
310 
acpi_hw_validate_io_block(u64 address,u32 bit_width,u32 count)311 acpi_status acpi_hw_validate_io_block(u64 address, u32 bit_width, u32 count)
312 {
313 	acpi_status status;
314 
315 	while (count--) {
316 		status = acpi_hw_validate_io_request((acpi_io_address)address,
317 						     bit_width);
318 		if (ACPI_FAILURE(status))
319 			return_ACPI_STATUS(status);
320 
321 		address += ACPI_DIV_8(bit_width);
322 	}
323 
324 	return_ACPI_STATUS(AE_OK);
325 }
326