1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
4 * Module Name: exfield - AML execution - field_unit read/write
6 * Copyright (C) 2000 - 2022, Intel Corp.
8 *****************************************************************************/
10 #include <acpi/acpi.h>
16 #define _COMPONENT ACPI_EXECUTER
17 ACPI_MODULE_NAME("exfield")
20 * This table maps the various Attrib protocols to the byte transfer
21 * length. Used for the generic serial bus.
23 #define ACPI_INVALID_PROTOCOL_ID 0x80
24 #define ACPI_MAX_PROTOCOL_ID 0x0F
25 static 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 */
44 #define PCC_MASTER_SUBSPACE 3
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.
52 #define GENERIC_SUBSPACE_COMMAND(a) (4 == a || a == 5)
53 #define MASTER_SUBSPACE_COMMAND(a) (12 <= a && a <= 15)
55 /*******************************************************************************
57 * FUNCTION: acpi_ex_get_protocol_buffer_length
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
64 * RETURN: Status and decoded byte transfer length
66 * DESCRIPTION: This routine returns the length of the generic_serial_bus
69 ******************************************************************************/
72 acpi_ex_get_protocol_buffer_length(u32 protocol_id, u32 *return_length)
75 if ((protocol_id > ACPI_MAX_PROTOCOL_ID) ||
76 (acpi_protocol_lengths[protocol_id] == ACPI_INVALID_PROTOCOL_ID)) {
78 "Invalid Field/AccessAs protocol ID: 0x%4.4X",
81 return (AE_AML_PROTOCOL);
84 *return_length = acpi_protocol_lengths[protocol_id];
88 /*******************************************************************************
90 * FUNCTION: acpi_ex_read_data_from_field
92 * PARAMETERS: walk_state - Current execution state
93 * obj_desc - The named field
94 * ret_buffer_desc - Where the return data object is stored
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.
102 ******************************************************************************/
105 acpi_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)
110 union acpi_operand_object *buffer_desc;
114 ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
116 /* Parameter validation */
119 return_ACPI_STATUS(AE_AML_NO_OPERAND);
121 if (!ret_buffer_desc) {
122 return_ACPI_STATUS(AE_BAD_PARAMETER);
125 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
127 * If the buffer_field arguments have not been previously evaluated,
128 * evaluate them now and save the results.
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);
136 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
137 (obj_desc->field.region_obj->region.space_id ==
139 || obj_desc->field.region_obj->region.space_id ==
141 || obj_desc->field.region_obj->region.space_id ==
143 || obj_desc->field.region_obj->region.space_id ==
144 ACPI_ADR_SPACE_PLATFORM_RT)) {
146 /* SMBus, GSBus, IPMI serial */
148 status = acpi_ex_read_serial_bus(obj_desc, ret_buffer_desc);
149 return_ACPI_STATUS(status);
153 * Allocate a buffer for the contents of the field.
155 * If the field is larger than the current integer width, create
156 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
157 * the use of arithmetic operators on the returned value if the
158 * field size is equal or smaller than an Integer.
160 * However, all buffer fields created by create_field operator needs to
161 * remain as a buffer to match other AML interpreter implementations.
163 * Note: Field.length is in bits.
166 (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
168 if (buffer_length > acpi_gbl_integer_byte_width ||
169 (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD &&
170 obj_desc->buffer_field.is_create_field)) {
172 /* Field is too large for an Integer, create a Buffer instead */
174 buffer_desc = acpi_ut_create_buffer_object(buffer_length);
176 return_ACPI_STATUS(AE_NO_MEMORY);
178 buffer = buffer_desc->buffer.pointer;
180 /* Field will fit within an Integer (normal case) */
182 buffer_desc = acpi_ut_create_integer_object((u64) 0);
184 return_ACPI_STATUS(AE_NO_MEMORY);
187 buffer_length = acpi_gbl_integer_byte_width;
188 buffer = &buffer_desc->integer.value;
191 if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
192 (obj_desc->field.region_obj->region.space_id ==
193 ACPI_ADR_SPACE_GPIO)) {
195 /* General Purpose I/O */
197 status = acpi_ex_read_gpio(obj_desc, buffer);
199 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
200 (obj_desc->field.region_obj->region.space_id ==
201 ACPI_ADR_SPACE_PLATFORM_COMM)) {
203 * Reading from a PCC field unit does not require the handler because
204 * it only requires reading from the internal_pcc_buffer.
206 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
207 "PCC FieldRead bits %u\n",
208 obj_desc->field.bit_length));
211 obj_desc->field.region_obj->field.internal_pcc_buffer +
212 obj_desc->field.base_byte_offset,
213 (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
216 *ret_buffer_desc = buffer_desc;
220 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
221 "FieldRead [TO]: Obj %p, Type %X, Buf %p, ByteLen %X\n",
222 obj_desc, obj_desc->common.type, buffer,
224 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
225 "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
226 obj_desc->common_field.bit_length,
227 obj_desc->common_field.start_field_bit_offset,
228 obj_desc->common_field.base_byte_offset));
230 /* Lock entire transaction if requested */
232 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
234 /* Read from the field */
236 status = acpi_ex_extract_from_field(obj_desc, buffer, buffer_length);
237 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
240 if (ACPI_FAILURE(status)) {
241 acpi_ut_remove_reference(buffer_desc);
243 *ret_buffer_desc = buffer_desc;
246 return_ACPI_STATUS(status);
249 /*******************************************************************************
251 * FUNCTION: acpi_ex_write_data_to_field
253 * PARAMETERS: source_desc - Contains data to write
254 * obj_desc - The named field
255 * result_desc - Where the return value is returned, if any
259 * DESCRIPTION: Write to a named field
261 ******************************************************************************/
264 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
265 union acpi_operand_object *obj_desc,
266 union acpi_operand_object **result_desc)
273 ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
275 /* Parameter validation */
277 if (!source_desc || !obj_desc) {
278 return_ACPI_STATUS(AE_AML_NO_OPERAND);
281 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
283 * If the buffer_field arguments have not been previously evaluated,
284 * evaluate them now and save the results.
286 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
287 status = acpi_ds_get_buffer_field_arguments(obj_desc);
288 if (ACPI_FAILURE(status)) {
289 return_ACPI_STATUS(status);
292 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
293 (obj_desc->field.region_obj->region.space_id ==
294 ACPI_ADR_SPACE_GPIO)) {
296 /* General Purpose I/O */
298 status = acpi_ex_write_gpio(source_desc, obj_desc, result_desc);
299 return_ACPI_STATUS(status);
300 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
301 (obj_desc->field.region_obj->region.space_id ==
303 || obj_desc->field.region_obj->region.space_id ==
305 || obj_desc->field.region_obj->region.space_id ==
307 || obj_desc->field.region_obj->region.space_id ==
308 ACPI_ADR_SPACE_PLATFORM_RT)) {
310 /* SMBus, GSBus, IPMI serial */
313 acpi_ex_write_serial_bus(source_desc, obj_desc,
315 return_ACPI_STATUS(status);
316 } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
317 (obj_desc->field.region_obj->region.space_id ==
318 ACPI_ADR_SPACE_PLATFORM_COMM)) {
320 * According to the spec a write to the COMD field will invoke the
321 * region handler. Otherwise, write to the pcc_internal buffer. This
322 * implementation will use the offsets specified rather than the name
323 * of the field. This is considered safer because some firmware tools
324 * are known to obfiscate named objects.
327 (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
329 memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer +
330 obj_desc->field.base_byte_offset,
331 source_desc->buffer.pointer, data_length);
333 if (MASTER_SUBSPACE_COMMAND(obj_desc->field.base_byte_offset)) {
335 /* Perform the write */
337 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
338 "PCC COMD field has been written. Invoking PCC handler now.\n"));
341 acpi_ex_access_region(obj_desc, 0,
342 (u64 *)obj_desc->field.
346 return_ACPI_STATUS(status);
351 /* Get a pointer to the data to be written */
353 switch (source_desc->common.type) {
354 case ACPI_TYPE_INTEGER:
356 buffer = &source_desc->integer.value;
357 buffer_length = sizeof(source_desc->integer.value);
360 case ACPI_TYPE_BUFFER:
362 buffer = source_desc->buffer.pointer;
363 buffer_length = source_desc->buffer.length;
366 case ACPI_TYPE_STRING:
368 buffer = source_desc->string.pointer;
369 buffer_length = source_desc->string.length;
373 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
376 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
377 "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
379 acpi_ut_get_type_name(source_desc->common.type),
380 source_desc->common.type, buffer, buffer_length));
382 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
383 "FieldWrite [TO]: Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
385 acpi_ut_get_type_name(obj_desc->common.type),
386 obj_desc->common.type,
387 obj_desc->common_field.bit_length,
388 obj_desc->common_field.start_field_bit_offset,
389 obj_desc->common_field.base_byte_offset));
391 /* Lock entire transaction if requested */
393 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
395 /* Write to the field */
397 status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
398 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
399 return_ACPI_STATUS(status);