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v5.9
  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 - 2020, 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
144		/* SMBus, GSBus, IPMI serial */
145
146		status = acpi_ex_read_serial_bus(obj_desc, ret_buffer_desc);
147		return_ACPI_STATUS(status);
148	}
149
150	/*
151	 * Allocate a buffer for the contents of the field.
152	 *
153	 * If the field is larger than the current integer width, create
154	 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
155	 * the use of arithmetic operators on the returned value if the
156	 * field size is equal or smaller than an Integer.
157	 *
158	 * However, all buffer fields created by create_field operator needs to
159	 * remain as a buffer to match other AML interpreter implementations.
160	 *
161	 * Note: Field.length is in bits.
162	 */
163	buffer_length =
164	    (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
165
166	if (buffer_length > acpi_gbl_integer_byte_width ||
167	    (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD &&
168	     obj_desc->buffer_field.is_create_field)) {
169
170		/* Field is too large for an Integer, create a Buffer instead */
171
172		buffer_desc = acpi_ut_create_buffer_object(buffer_length);
173		if (!buffer_desc) {
174			return_ACPI_STATUS(AE_NO_MEMORY);
175		}
176		buffer = buffer_desc->buffer.pointer;
177	} else {
178		/* Field will fit within an Integer (normal case) */
179
180		buffer_desc = acpi_ut_create_integer_object((u64) 0);
181		if (!buffer_desc) {
182			return_ACPI_STATUS(AE_NO_MEMORY);
183		}
184
185		buffer_length = acpi_gbl_integer_byte_width;
186		buffer = &buffer_desc->integer.value;
187	}
188
189	if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
190	    (obj_desc->field.region_obj->region.space_id ==
191	     ACPI_ADR_SPACE_GPIO)) {
192
193		/* General Purpose I/O */
194
195		status = acpi_ex_read_gpio(obj_desc, buffer);
196		goto exit;
197	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
198		   (obj_desc->field.region_obj->region.space_id ==
199		    ACPI_ADR_SPACE_PLATFORM_COMM)) {
200		/*
201		 * Reading from a PCC field unit does not require the handler because
202		 * it only requires reading from the internal_pcc_buffer.
203		 */
204		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
205				  "PCC FieldRead bits %u\n",
206				  obj_desc->field.bit_length));
207
208		memcpy(buffer,
209		       obj_desc->field.region_obj->field.internal_pcc_buffer +
210		       obj_desc->field.base_byte_offset,
211		       (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
212							      bit_length));
213
214		*ret_buffer_desc = buffer_desc;
215		return AE_OK;
216	}
217
218	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
219			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
220			  obj_desc, obj_desc->common.type, buffer,
221			  buffer_length));
222	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
223			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
224			  obj_desc->common_field.bit_length,
225			  obj_desc->common_field.start_field_bit_offset,
226			  obj_desc->common_field.base_byte_offset));
227
228	/* Lock entire transaction if requested */
229
230	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
231
232	/* Read from the field */
233
234	status = acpi_ex_extract_from_field(obj_desc, buffer, buffer_length);
235	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
236
237exit:
238	if (ACPI_FAILURE(status)) {
239		acpi_ut_remove_reference(buffer_desc);
240	} else {
241		*ret_buffer_desc = buffer_desc;
242	}
243
244	return_ACPI_STATUS(status);
245}
246
247/*******************************************************************************
248 *
249 * FUNCTION:    acpi_ex_write_data_to_field
250 *
251 * PARAMETERS:  source_desc         - Contains data to write
252 *              obj_desc            - The named field
253 *              result_desc         - Where the return value is returned, if any
254 *
255 * RETURN:      Status
256 *
257 * DESCRIPTION: Write to a named field
258 *
259 ******************************************************************************/
260
261acpi_status
262acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
263			    union acpi_operand_object *obj_desc,
264			    union acpi_operand_object **result_desc)
265{
266	acpi_status status;
267	u32 buffer_length;
268	u32 data_length;
269	void *buffer;
270
271	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
272
273	/* Parameter validation */
274
275	if (!source_desc || !obj_desc) {
276		return_ACPI_STATUS(AE_AML_NO_OPERAND);
277	}
278
279	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
280		/*
281		 * If the buffer_field arguments have not been previously evaluated,
282		 * evaluate them now and save the results.
283		 */
284		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
285			status = acpi_ds_get_buffer_field_arguments(obj_desc);
286			if (ACPI_FAILURE(status)) {
287				return_ACPI_STATUS(status);
288			}
289		}
290	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
291		   (obj_desc->field.region_obj->region.space_id ==
292		    ACPI_ADR_SPACE_GPIO)) {
293
294		/* General Purpose I/O */
295
296		status = acpi_ex_write_gpio(source_desc, obj_desc, result_desc);
297		return_ACPI_STATUS(status);
298	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
299		   (obj_desc->field.region_obj->region.space_id ==
300		    ACPI_ADR_SPACE_SMBUS
301		    || obj_desc->field.region_obj->region.space_id ==
302		    ACPI_ADR_SPACE_GSBUS
303		    || obj_desc->field.region_obj->region.space_id ==
304		    ACPI_ADR_SPACE_IPMI)) {
305
306		/* SMBus, GSBus, IPMI serial */
307
308		status =
309		    acpi_ex_write_serial_bus(source_desc, obj_desc,
310					     result_desc);
311		return_ACPI_STATUS(status);
312	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
313		   (obj_desc->field.region_obj->region.space_id ==
314		    ACPI_ADR_SPACE_PLATFORM_COMM)) {
315		/*
316		 * According to the spec a write to the COMD field will invoke the
317		 * region handler. Otherwise, write to the pcc_internal buffer. This
318		 * implementation will use the offsets specified rather than the name
319		 * of the field. This is considered safer because some firmware tools
320		 * are known to obfiscate named objects.
321		 */
322		data_length =
323		    (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
324							   bit_length);
325		memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer +
326		       obj_desc->field.base_byte_offset,
327		       source_desc->buffer.pointer, data_length);
328
329		if ((obj_desc->field.region_obj->region.address ==
330		     PCC_MASTER_SUBSPACE
331		     && MASTER_SUBSPACE_COMMAND(obj_desc->field.
332						base_byte_offset))
333		    || GENERIC_SUBSPACE_COMMAND(obj_desc->field.
334						base_byte_offset)) {
335
336			/* Perform the write */
337
338			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
339					  "PCC COMD field has been written. Invoking PCC handler now.\n"));
340
341			status =
342			    acpi_ex_access_region(obj_desc, 0,
343						  (u64 *)obj_desc->field.
344						  region_obj->field.
345						  internal_pcc_buffer,
346						  ACPI_WRITE);
347			return_ACPI_STATUS(status);
348		}
349		return (AE_OK);
350	}
351
352	/* Get a pointer to the data to be written */
353
354	switch (source_desc->common.type) {
355	case ACPI_TYPE_INTEGER:
356
357		buffer = &source_desc->integer.value;
358		buffer_length = sizeof(source_desc->integer.value);
359		break;
360
361	case ACPI_TYPE_BUFFER:
362
363		buffer = source_desc->buffer.pointer;
364		buffer_length = source_desc->buffer.length;
365		break;
366
367	case ACPI_TYPE_STRING:
368
369		buffer = source_desc->string.pointer;
370		buffer_length = source_desc->string.length;
371		break;
372
373	default:
374		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
375	}
376
377	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
378			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
379			  source_desc,
380			  acpi_ut_get_type_name(source_desc->common.type),
381			  source_desc->common.type, buffer, buffer_length));
382
383	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
384			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
385			  obj_desc,
386			  acpi_ut_get_type_name(obj_desc->common.type),
387			  obj_desc->common.type,
388			  obj_desc->common_field.bit_length,
389			  obj_desc->common_field.start_field_bit_offset,
390			  obj_desc->common_field.base_byte_offset));
391
392	/* Lock entire transaction if requested */
393
394	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
395
396	/* Write to the field */
397
398	status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
399	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
400	return_ACPI_STATUS(status);
401}
v5.4
  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 - 2019, 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
 25const 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.
 
100 *
101 ******************************************************************************/
102
103acpi_status
104acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
105			     union acpi_operand_object *obj_desc,
106			     union acpi_operand_object **ret_buffer_desc)
107{
108	acpi_status status;
109	union acpi_operand_object *buffer_desc;
110	void *buffer;
111	u32 buffer_length;
112
113	ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
114
115	/* Parameter validation */
116
117	if (!obj_desc) {
118		return_ACPI_STATUS(AE_AML_NO_OPERAND);
119	}
120	if (!ret_buffer_desc) {
121		return_ACPI_STATUS(AE_BAD_PARAMETER);
122	}
123
124	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
125		/*
126		 * If the buffer_field arguments have not been previously evaluated,
127		 * evaluate them now and save the results.
128		 */
129		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
130			status = acpi_ds_get_buffer_field_arguments(obj_desc);
131			if (ACPI_FAILURE(status)) {
132				return_ACPI_STATUS(status);
133			}
134		}
135	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
136		   (obj_desc->field.region_obj->region.space_id ==
137		    ACPI_ADR_SPACE_SMBUS
138		    || obj_desc->field.region_obj->region.space_id ==
139		    ACPI_ADR_SPACE_GSBUS
140		    || obj_desc->field.region_obj->region.space_id ==
141		    ACPI_ADR_SPACE_IPMI)) {
142
143		/* SMBus, GSBus, IPMI serial */
144
145		status = acpi_ex_read_serial_bus(obj_desc, ret_buffer_desc);
146		return_ACPI_STATUS(status);
147	}
148
149	/*
150	 * Allocate a buffer for the contents of the field.
151	 *
152	 * If the field is larger than the current integer width, create
153	 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
154	 * the use of arithmetic operators on the returned value if the
155	 * field size is equal or smaller than an Integer.
156	 *
 
 
 
157	 * Note: Field.length is in bits.
158	 */
159	buffer_length =
160	    (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
161
162	if (buffer_length > acpi_gbl_integer_byte_width) {
 
 
163
164		/* Field is too large for an Integer, create a Buffer instead */
165
166		buffer_desc = acpi_ut_create_buffer_object(buffer_length);
167		if (!buffer_desc) {
168			return_ACPI_STATUS(AE_NO_MEMORY);
169		}
170		buffer = buffer_desc->buffer.pointer;
171	} else {
172		/* Field will fit within an Integer (normal case) */
173
174		buffer_desc = acpi_ut_create_integer_object((u64) 0);
175		if (!buffer_desc) {
176			return_ACPI_STATUS(AE_NO_MEMORY);
177		}
178
179		buffer_length = acpi_gbl_integer_byte_width;
180		buffer = &buffer_desc->integer.value;
181	}
182
183	if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
184	    (obj_desc->field.region_obj->region.space_id ==
185	     ACPI_ADR_SPACE_GPIO)) {
186
187		/* General Purpose I/O */
188
189		status = acpi_ex_read_gpio(obj_desc, buffer);
190		goto exit;
191	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
192		   (obj_desc->field.region_obj->region.space_id ==
193		    ACPI_ADR_SPACE_PLATFORM_COMM)) {
194		/*
195		 * Reading from a PCC field unit does not require the handler because
196		 * it only requires reading from the internal_pcc_buffer.
197		 */
198		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
199				  "PCC FieldRead bits %u\n",
200				  obj_desc->field.bit_length));
201
202		memcpy(buffer,
203		       obj_desc->field.region_obj->field.internal_pcc_buffer +
204		       obj_desc->field.base_byte_offset,
205		       (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
206							      bit_length));
207
208		*ret_buffer_desc = buffer_desc;
209		return AE_OK;
210	}
211
212	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
213			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
214			  obj_desc, obj_desc->common.type, buffer,
215			  buffer_length));
216	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
217			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
218			  obj_desc->common_field.bit_length,
219			  obj_desc->common_field.start_field_bit_offset,
220			  obj_desc->common_field.base_byte_offset));
221
222	/* Lock entire transaction if requested */
223
224	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
225
226	/* Read from the field */
227
228	status = acpi_ex_extract_from_field(obj_desc, buffer, buffer_length);
229	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
230
231exit:
232	if (ACPI_FAILURE(status)) {
233		acpi_ut_remove_reference(buffer_desc);
234	} else {
235		*ret_buffer_desc = buffer_desc;
236	}
237
238	return_ACPI_STATUS(status);
239}
240
241/*******************************************************************************
242 *
243 * FUNCTION:    acpi_ex_write_data_to_field
244 *
245 * PARAMETERS:  source_desc         - Contains data to write
246 *              obj_desc            - The named field
247 *              result_desc         - Where the return value is returned, if any
248 *
249 * RETURN:      Status
250 *
251 * DESCRIPTION: Write to a named field
252 *
253 ******************************************************************************/
254
255acpi_status
256acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
257			    union acpi_operand_object *obj_desc,
258			    union acpi_operand_object **result_desc)
259{
260	acpi_status status;
261	u32 buffer_length;
262	u32 data_length;
263	void *buffer;
264
265	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
266
267	/* Parameter validation */
268
269	if (!source_desc || !obj_desc) {
270		return_ACPI_STATUS(AE_AML_NO_OPERAND);
271	}
272
273	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
274		/*
275		 * If the buffer_field arguments have not been previously evaluated,
276		 * evaluate them now and save the results.
277		 */
278		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
279			status = acpi_ds_get_buffer_field_arguments(obj_desc);
280			if (ACPI_FAILURE(status)) {
281				return_ACPI_STATUS(status);
282			}
283		}
284	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
285		   (obj_desc->field.region_obj->region.space_id ==
286		    ACPI_ADR_SPACE_GPIO)) {
287
288		/* General Purpose I/O */
289
290		status = acpi_ex_write_gpio(source_desc, obj_desc, result_desc);
291		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_SMBUS
295		    || obj_desc->field.region_obj->region.space_id ==
296		    ACPI_ADR_SPACE_GSBUS
297		    || obj_desc->field.region_obj->region.space_id ==
298		    ACPI_ADR_SPACE_IPMI)) {
299
300		/* SMBus, GSBus, IPMI serial */
301
302		status =
303		    acpi_ex_write_serial_bus(source_desc, obj_desc,
304					     result_desc);
305		return_ACPI_STATUS(status);
306	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
307		   (obj_desc->field.region_obj->region.space_id ==
308		    ACPI_ADR_SPACE_PLATFORM_COMM)) {
309		/*
310		 * According to the spec a write to the COMD field will invoke the
311		 * region handler. Otherwise, write to the pcc_internal buffer. This
312		 * implementation will use the offsets specified rather than the name
313		 * of the field. This is considered safer because some firmware tools
314		 * are known to obfiscate named objects.
315		 */
316		data_length =
317		    (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
318							   bit_length);
319		memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer +
320		       obj_desc->field.base_byte_offset,
321		       source_desc->buffer.pointer, data_length);
322
323		if ((obj_desc->field.region_obj->region.address ==
324		     PCC_MASTER_SUBSPACE
325		     && MASTER_SUBSPACE_COMMAND(obj_desc->field.
326						base_byte_offset))
327		    || GENERIC_SUBSPACE_COMMAND(obj_desc->field.
328						base_byte_offset)) {
329
330			/* Perform the write */
331
332			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
333					  "PCC COMD field has been written. Invoking PCC handler now.\n"));
334
335			status =
336			    acpi_ex_access_region(obj_desc, 0,
337						  (u64 *)obj_desc->field.
338						  region_obj->field.
339						  internal_pcc_buffer,
340						  ACPI_WRITE);
341			return_ACPI_STATUS(status);
342		}
343		return (AE_OK);
344	}
345
346	/* Get a pointer to the data to be written */
347
348	switch (source_desc->common.type) {
349	case ACPI_TYPE_INTEGER:
350
351		buffer = &source_desc->integer.value;
352		buffer_length = sizeof(source_desc->integer.value);
353		break;
354
355	case ACPI_TYPE_BUFFER:
356
357		buffer = source_desc->buffer.pointer;
358		buffer_length = source_desc->buffer.length;
359		break;
360
361	case ACPI_TYPE_STRING:
362
363		buffer = source_desc->string.pointer;
364		buffer_length = source_desc->string.length;
365		break;
366
367	default:
368		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
369	}
370
371	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
372			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
373			  source_desc,
374			  acpi_ut_get_type_name(source_desc->common.type),
375			  source_desc->common.type, buffer, buffer_length));
376
377	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
378			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
379			  obj_desc,
380			  acpi_ut_get_type_name(obj_desc->common.type),
381			  obj_desc->common.type,
382			  obj_desc->common_field.bit_length,
383			  obj_desc->common_field.start_field_bit_offset,
384			  obj_desc->common_field.base_byte_offset));
385
386	/* Lock entire transaction if requested */
387
388	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
389
390	/* Write to the field */
391
392	status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
393	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
394	return_ACPI_STATUS(status);
395}