xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision 612c2932)
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 - 2023, 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
17 ACPI_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
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 */
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 
71 acpi_status
acpi_ex_get_protocol_buffer_length(u32 protocol_id,u32 * return_length)72 acpi_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 
104 acpi_status
acpi_ex_read_data_from_field(struct acpi_walk_state * walk_state,union acpi_operand_object * obj_desc,union acpi_operand_object ** ret_buffer_desc)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)
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, 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_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((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(buffer,
213 		       obj_desc->field.region_obj->field.internal_pcc_buffer +
214 		       obj_desc->field.base_byte_offset,
215 		       (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(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(obj_desc->common_field.field_flags);
240 
241 exit:
242 	if (ACPI_FAILURE(status)) {
243 		acpi_ut_remove_reference(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 
265 acpi_status
acpi_ex_write_data_to_field(union acpi_operand_object * source_desc,union acpi_operand_object * obj_desc,union acpi_operand_object ** result_desc)266 acpi_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, 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 					     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(obj_desc->field.region_obj->field.internal_pcc_buffer +
334 		       obj_desc->field.base_byte_offset,
335 		       source_desc->buffer.pointer, 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, 0,
346 						  (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(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(obj_desc->common_field.field_flags);
403 	return_ACPI_STATUS(status);
404 }
405