xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision 3213486f)
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
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 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
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.
100  *
101  ******************************************************************************/
102 
103 acpi_status
104 acpi_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 
231 exit:
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 
255 acpi_status
256 acpi_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 }
396