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 (MASTER_SUBSPACE_COMMAND(obj_desc->field.base_byte_offset)) {
330
331			/* Perform the write */
332
333			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
334					  "PCC COMD field has been written. Invoking PCC handler now.\n"));
335
336			status =
337			    acpi_ex_access_region(obj_desc, 0,
338						  (u64 *)obj_desc->field.
339						  region_obj->field.
340						  internal_pcc_buffer,
341						  ACPI_WRITE);
342			return_ACPI_STATUS(status);
343		}
344		return (AE_OK);
345	}
346
347	/* Get a pointer to the data to be written */
348
349	switch (source_desc->common.type) {
350	case ACPI_TYPE_INTEGER:
351
352		buffer = &source_desc->integer.value;
353		buffer_length = sizeof(source_desc->integer.value);
354		break;
355
356	case ACPI_TYPE_BUFFER:
357
358		buffer = source_desc->buffer.pointer;
359		buffer_length = source_desc->buffer.length;
360		break;
361
362	case ACPI_TYPE_STRING:
363
364		buffer = source_desc->string.pointer;
365		buffer_length = source_desc->string.length;
366		break;
367
368	default:
369		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
370	}
371
372	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
373			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
374			  source_desc,
375			  acpi_ut_get_type_name(source_desc->common.type),
376			  source_desc->common.type, buffer, buffer_length));
377
378	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
379			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
380			  obj_desc,
381			  acpi_ut_get_type_name(obj_desc->common.type),
382			  obj_desc->common.type,
383			  obj_desc->common_field.bit_length,
384			  obj_desc->common_field.start_field_bit_offset,
385			  obj_desc->common_field.base_byte_offset));
386
387	/* Lock entire transaction if requested */
388
389	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
390
391	/* Write to the field */
392
393	status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
394	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
395	return_ACPI_STATUS(status);
396}
397