1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: exfield - AML execution - field_unit read/write
5 *
6 * Copyright (C) 2000 - 2025, Intel Corp.
7 *
8 *****************************************************************************/
9
10#include <acpi/acpi.h>
11#include "accommon.h"
12#include "acdispat.h"
13#include "acinterp.h"
14#include "amlcode.h"
15
16#define _COMPONENT ACPI_EXECUTER
17ACPI_MODULE_NAME("exfield")
18
19/*
20 * This table maps the various Attrib protocols to the byte transfer
21 * length. Used for the generic serial bus.
22 */
23#define ACPI_INVALID_PROTOCOL_ID 0x80
24#define ACPI_MAX_PROTOCOL_ID 0x0F
25static const u8 acpi_protocol_lengths[] = {
26 ACPI_INVALID_PROTOCOL_ID, /* 0 - reserved */
27 ACPI_INVALID_PROTOCOL_ID, /* 1 - reserved */
28 0x00, /* 2 - ATTRIB_QUICK */
29 ACPI_INVALID_PROTOCOL_ID, /* 3 - reserved */
30 0x01, /* 4 - ATTRIB_SEND_RECEIVE */
31 ACPI_INVALID_PROTOCOL_ID, /* 5 - reserved */
32 0x01, /* 6 - ATTRIB_BYTE */
33 ACPI_INVALID_PROTOCOL_ID, /* 7 - reserved */
34 0x02, /* 8 - ATTRIB_WORD */
35 ACPI_INVALID_PROTOCOL_ID, /* 9 - reserved */
36 0xFF, /* A - ATTRIB_BLOCK */
37 0xFF, /* B - ATTRIB_BYTES */
38 0x02, /* C - ATTRIB_PROCESS_CALL */
39 0xFF, /* D - ATTRIB_BLOCK_PROCESS_CALL */
40 0xFF, /* E - ATTRIB_RAW_BYTES */
41 0xFF /* F - ATTRIB_RAW_PROCESS_BYTES */
42};
43
44#define PCC_MASTER_SUBSPACE 3
45
46/*
47 * The following macros determine a given offset is a COMD field.
48 * According to the specification, generic subspaces (types 0-2) contains a
49 * 2-byte COMD field at offset 4 and master subspaces (type 3) contains a 4-byte
50 * COMD field starting at offset 12.
51 */
52#define GENERIC_SUBSPACE_COMMAND(a) (4 == a || a == 5)
53#define MASTER_SUBSPACE_COMMAND(a) (12 <= a && a <= 15)
54
55/*******************************************************************************
56 *
57 * FUNCTION: acpi_ex_get_protocol_buffer_length
58 *
59 * PARAMETERS: protocol_id - The type of the protocol indicated by region
60 * field access attributes
61 * return_length - Where the protocol byte transfer length is
62 * returned
63 *
64 * RETURN: Status and decoded byte transfer length
65 *
66 * DESCRIPTION: This routine returns the length of the generic_serial_bus
67 * protocol bytes
68 *
69 ******************************************************************************/
70
71acpi_status
72acpi_ex_get_protocol_buffer_length(u32 protocol_id, u32 *return_length)
73{
74
75 if ((protocol_id > ACPI_MAX_PROTOCOL_ID) ||
76 (acpi_protocol_lengths[protocol_id] == ACPI_INVALID_PROTOCOL_ID)) {
77 ACPI_ERROR((AE_INFO,
78 "Invalid Field/AccessAs protocol ID: 0x%4.4X",
79 protocol_id));
80
81 return (AE_AML_PROTOCOL);
82 }
83
84 *return_length = acpi_protocol_lengths[protocol_id];
85 return (AE_OK);
86}
87
88/*******************************************************************************
89 *
90 * FUNCTION: acpi_ex_read_data_from_field
91 *
92 * PARAMETERS: walk_state - Current execution state
93 * obj_desc - The named field
94 * ret_buffer_desc - Where the return data object is stored
95 *
96 * RETURN: Status
97 *
98 * DESCRIPTION: Read from a named field. Returns either an Integer or a
99 * Buffer, depending on the size of the field and whether if a
100 * field is created by the create_field() operator.
101 *
102 ******************************************************************************/
103
104acpi_status
105acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
106 union acpi_operand_object *obj_desc,
107 union acpi_operand_object **ret_buffer_desc)
108{
109 acpi_status status;
110 union acpi_operand_object *buffer_desc;
111 void *buffer;
112 u32 buffer_length;
113
114 ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
115
116 /* Parameter validation */
117
118 if (!obj_desc) {
119 return_ACPI_STATUS(AE_AML_NO_OPERAND);
120 }
121 if (!ret_buffer_desc) {
122 return_ACPI_STATUS(AE_BAD_PARAMETER);
123 }
124
125 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
126 /*
127 * If the buffer_field arguments have not been previously evaluated,
128 * evaluate them now and save the results.
129 */
130 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
131 status = acpi_ds_get_buffer_field_arguments(obj_desc);
132 if (ACPI_FAILURE(status)) {
133 return_ACPI_STATUS(status);
134 }
135 }
136 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
137 (obj_desc->field.region_obj->region.space_id ==
138 ACPI_ADR_SPACE_SMBUS
139 || obj_desc->field.region_obj->region.space_id ==
140 ACPI_ADR_SPACE_GSBUS
141 || obj_desc->field.region_obj->region.space_id ==
142 ACPI_ADR_SPACE_IPMI
143 || obj_desc->field.region_obj->region.space_id ==
144 ACPI_ADR_SPACE_PLATFORM_RT
145 || obj_desc->field.region_obj->region.space_id ==
146 ACPI_ADR_SPACE_FIXED_HARDWARE)) {
147
148 /* SMBus, GSBus, IPMI serial */
149
150 status = acpi_ex_read_serial_bus(obj_desc, return_buffer: ret_buffer_desc);
151 return_ACPI_STATUS(status);
152 }
153
154 /*
155 * Allocate a buffer for the contents of the field.
156 *
157 * If the field is larger than the current integer width, create
158 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
159 * the use of arithmetic operators on the returned value if the
160 * field size is equal or smaller than an Integer.
161 *
162 * However, all buffer fields created by create_field operator needs to
163 * remain as a buffer to match other AML interpreter implementations.
164 *
165 * Note: Field.length is in bits.
166 */
167 buffer_length =
168 (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
169
170 if (buffer_length > acpi_gbl_integer_byte_width ||
171 (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD &&
172 obj_desc->buffer_field.is_create_field)) {
173
174 /* Field is too large for an Integer, create a Buffer instead */
175
176 buffer_desc = acpi_ut_create_buffer_object(buffer_size: buffer_length);
177 if (!buffer_desc) {
178 return_ACPI_STATUS(AE_NO_MEMORY);
179 }
180 buffer = buffer_desc->buffer.pointer;
181 } else {
182 /* Field will fit within an Integer (normal case) */
183
184 buffer_desc = acpi_ut_create_integer_object(value: (u64) 0);
185 if (!buffer_desc) {
186 return_ACPI_STATUS(AE_NO_MEMORY);
187 }
188
189 buffer_length = acpi_gbl_integer_byte_width;
190 buffer = &buffer_desc->integer.value;
191 }
192
193 if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
194 (obj_desc->field.region_obj->region.space_id ==
195 ACPI_ADR_SPACE_GPIO)) {
196
197 /* General Purpose I/O */
198
199 status = acpi_ex_read_gpio(obj_desc, buffer);
200 goto exit;
201 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
202 (obj_desc->field.region_obj->region.space_id ==
203 ACPI_ADR_SPACE_PLATFORM_COMM)) {
204 /*
205 * Reading from a PCC field unit does not require the handler because
206 * it only requires reading from the internal_pcc_buffer.
207 */
208 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
209 "PCC FieldRead bits %u\n",
210 obj_desc->field.bit_length));
211
212 memcpy(to: buffer,
213 from: obj_desc->field.region_obj->field.internal_pcc_buffer +
214 obj_desc->field.base_byte_offset,
215 len: (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
216 bit_length));
217
218 *ret_buffer_desc = buffer_desc;
219 return AE_OK;
220 }
221
222 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
223 "FieldRead [TO]: Obj %p, Type %X, Buf %p, ByteLen %X\n",
224 obj_desc, obj_desc->common.type, buffer,
225 buffer_length));
226 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
227 "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
228 obj_desc->common_field.bit_length,
229 obj_desc->common_field.start_field_bit_offset,
230 obj_desc->common_field.base_byte_offset));
231
232 /* Lock entire transaction if requested */
233
234 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
235
236 /* Read from the field */
237
238 status = acpi_ex_extract_from_field(obj_desc, buffer, buffer_length);
239 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
240
241exit:
242 if (ACPI_FAILURE(status)) {
243 acpi_ut_remove_reference(object: buffer_desc);
244 } else {
245 *ret_buffer_desc = buffer_desc;
246 }
247
248 return_ACPI_STATUS(status);
249}
250
251/*******************************************************************************
252 *
253 * FUNCTION: acpi_ex_write_data_to_field
254 *
255 * PARAMETERS: source_desc - Contains data to write
256 * obj_desc - The named field
257 * result_desc - Where the return value is returned, if any
258 *
259 * RETURN: Status
260 *
261 * DESCRIPTION: Write to a named field
262 *
263 ******************************************************************************/
264
265acpi_status
266acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
267 union acpi_operand_object *obj_desc,
268 union acpi_operand_object **result_desc)
269{
270 acpi_status status;
271 u32 buffer_length;
272 u32 data_length;
273 void *buffer;
274
275 ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
276
277 /* Parameter validation */
278
279 if (!source_desc || !obj_desc) {
280 return_ACPI_STATUS(AE_AML_NO_OPERAND);
281 }
282
283 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
284 /*
285 * If the buffer_field arguments have not been previously evaluated,
286 * evaluate them now and save the results.
287 */
288 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
289 status = acpi_ds_get_buffer_field_arguments(obj_desc);
290 if (ACPI_FAILURE(status)) {
291 return_ACPI_STATUS(status);
292 }
293 }
294 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
295 (obj_desc->field.region_obj->region.space_id ==
296 ACPI_ADR_SPACE_GPIO)) {
297
298 /* General Purpose I/O */
299
300 status = acpi_ex_write_gpio(source_desc, obj_desc, return_buffer: result_desc);
301 return_ACPI_STATUS(status);
302 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
303 (obj_desc->field.region_obj->region.space_id ==
304 ACPI_ADR_SPACE_SMBUS
305 || obj_desc->field.region_obj->region.space_id ==
306 ACPI_ADR_SPACE_GSBUS
307 || obj_desc->field.region_obj->region.space_id ==
308 ACPI_ADR_SPACE_IPMI
309 || obj_desc->field.region_obj->region.space_id ==
310 ACPI_ADR_SPACE_PLATFORM_RT
311 || obj_desc->field.region_obj->region.space_id ==
312 ACPI_ADR_SPACE_FIXED_HARDWARE)) {
313
314 /* SMBus, GSBus, IPMI serial */
315
316 status =
317 acpi_ex_write_serial_bus(source_desc, obj_desc,
318 return_buffer: result_desc);
319 return_ACPI_STATUS(status);
320 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
321 (obj_desc->field.region_obj->region.space_id ==
322 ACPI_ADR_SPACE_PLATFORM_COMM)) {
323 /*
324 * According to the spec a write to the COMD field will invoke the
325 * region handler. Otherwise, write to the pcc_internal buffer. This
326 * implementation will use the offsets specified rather than the name
327 * of the field. This is considered safer because some firmware tools
328 * are known to obfiscate named objects.
329 */
330 data_length =
331 (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
332 bit_length);
333 memcpy(to: obj_desc->field.region_obj->field.internal_pcc_buffer +
334 obj_desc->field.base_byte_offset,
335 from: source_desc->buffer.pointer, len: data_length);
336
337 if (MASTER_SUBSPACE_COMMAND(obj_desc->field.base_byte_offset)) {
338
339 /* Perform the write */
340
341 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
342 "PCC COMD field has been written. Invoking PCC handler now.\n"));
343
344 status =
345 acpi_ex_access_region(obj_desc, field_datum_byte_offset: 0,
346 value: (u64 *)obj_desc->field.
347 region_obj->field.
348 internal_pcc_buffer,
349 ACPI_WRITE);
350 return_ACPI_STATUS(status);
351 }
352 return (AE_OK);
353 }
354
355 /* Get a pointer to the data to be written */
356
357 switch (source_desc->common.type) {
358 case ACPI_TYPE_INTEGER:
359
360 buffer = &source_desc->integer.value;
361 buffer_length = sizeof(source_desc->integer.value);
362 break;
363
364 case ACPI_TYPE_BUFFER:
365
366 buffer = source_desc->buffer.pointer;
367 buffer_length = source_desc->buffer.length;
368 break;
369
370 case ACPI_TYPE_STRING:
371
372 buffer = source_desc->string.pointer;
373 buffer_length = source_desc->string.length;
374 break;
375
376 default:
377 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
378 }
379
380 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
381 "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
382 source_desc,
383 acpi_ut_get_type_name(source_desc->common.type),
384 source_desc->common.type, buffer, buffer_length));
385
386 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
387 "FieldWrite [TO]: Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
388 obj_desc,
389 acpi_ut_get_type_name(obj_desc->common.type),
390 obj_desc->common.type,
391 obj_desc->common_field.bit_length,
392 obj_desc->common_field.start_field_bit_offset,
393 obj_desc->common_field.base_byte_offset));
394
395 /* Lock entire transaction if requested */
396
397 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
398
399 /* Write to the field */
400
401 status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
402 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
403 return_ACPI_STATUS(status);
404}
405