xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision 7b6d864b)
1 /******************************************************************************
2  *
3  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2013, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acdispat.h"
47 #include "acinterp.h"
48 
49 #define _COMPONENT          ACPI_EXECUTER
50 ACPI_MODULE_NAME("exfield")
51 
52 /*******************************************************************************
53  *
54  * FUNCTION:    acpi_ex_read_data_from_field
55  *
56  * PARAMETERS:  walk_state          - Current execution state
57  *              obj_desc            - The named field
58  *              ret_buffer_desc     - Where the return data object is stored
59  *
60  * RETURN:      Status
61  *
62  * DESCRIPTION: Read from a named field. Returns either an Integer or a
63  *              Buffer, depending on the size of the field.
64  *
65  ******************************************************************************/
66 acpi_status
67 acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
68 			     union acpi_operand_object *obj_desc,
69 			     union acpi_operand_object **ret_buffer_desc)
70 {
71 	acpi_status status;
72 	union acpi_operand_object *buffer_desc;
73 	acpi_size length;
74 	void *buffer;
75 	u32 function;
76 
77 	ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
78 
79 	/* Parameter validation */
80 
81 	if (!obj_desc) {
82 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
83 	}
84 	if (!ret_buffer_desc) {
85 		return_ACPI_STATUS(AE_BAD_PARAMETER);
86 	}
87 
88 	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
89 		/*
90 		 * If the buffer_field arguments have not been previously evaluated,
91 		 * evaluate them now and save the results.
92 		 */
93 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
94 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
95 			if (ACPI_FAILURE(status)) {
96 				return_ACPI_STATUS(status);
97 			}
98 		}
99 	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
100 		   (obj_desc->field.region_obj->region.space_id ==
101 		    ACPI_ADR_SPACE_SMBUS
102 		    || obj_desc->field.region_obj->region.space_id ==
103 		    ACPI_ADR_SPACE_GSBUS
104 		    || obj_desc->field.region_obj->region.space_id ==
105 		    ACPI_ADR_SPACE_IPMI)) {
106 		/*
107 		 * This is an SMBus, GSBus or IPMI read. We must create a buffer to hold
108 		 * the data and then directly access the region handler.
109 		 *
110 		 * Note: SMBus and GSBus protocol value is passed in upper 16-bits of Function
111 		 */
112 		if (obj_desc->field.region_obj->region.space_id ==
113 		    ACPI_ADR_SPACE_SMBUS) {
114 			length = ACPI_SMBUS_BUFFER_SIZE;
115 			function =
116 			    ACPI_READ | (obj_desc->field.attribute << 16);
117 		} else if (obj_desc->field.region_obj->region.space_id ==
118 			   ACPI_ADR_SPACE_GSBUS) {
119 			length = ACPI_GSBUS_BUFFER_SIZE;
120 			function =
121 			    ACPI_READ | (obj_desc->field.attribute << 16);
122 		} else {	/* IPMI */
123 
124 			length = ACPI_IPMI_BUFFER_SIZE;
125 			function = ACPI_READ;
126 		}
127 
128 		buffer_desc = acpi_ut_create_buffer_object(length);
129 		if (!buffer_desc) {
130 			return_ACPI_STATUS(AE_NO_MEMORY);
131 		}
132 
133 		/* Lock entire transaction if requested */
134 
135 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
136 
137 		/* Call the region handler for the read */
138 
139 		status = acpi_ex_access_region(obj_desc, 0,
140 					       ACPI_CAST_PTR(u64,
141 							     buffer_desc->
142 							     buffer.pointer),
143 					       function);
144 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
145 		goto exit;
146 	}
147 
148 	/*
149 	 * Allocate a buffer for the contents of the field.
150 	 *
151 	 * If the field is larger than the current integer width, create
152 	 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
153 	 * the use of arithmetic operators on the returned value if the
154 	 * field size is equal or smaller than an Integer.
155 	 *
156 	 * Note: Field.length is in bits.
157 	 */
158 	length =
159 	    (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
160 	if (length > acpi_gbl_integer_byte_width) {
161 
162 		/* Field is too large for an Integer, create a Buffer instead */
163 
164 		buffer_desc = acpi_ut_create_buffer_object(length);
165 		if (!buffer_desc) {
166 			return_ACPI_STATUS(AE_NO_MEMORY);
167 		}
168 		buffer = buffer_desc->buffer.pointer;
169 	} else {
170 		/* Field will fit within an Integer (normal case) */
171 
172 		buffer_desc = acpi_ut_create_integer_object((u64) 0);
173 		if (!buffer_desc) {
174 			return_ACPI_STATUS(AE_NO_MEMORY);
175 		}
176 
177 		length = acpi_gbl_integer_byte_width;
178 		buffer = &buffer_desc->integer.value;
179 	}
180 
181 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
182 			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
183 			  obj_desc, obj_desc->common.type, buffer,
184 			  (u32) length));
185 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
186 			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
187 			  obj_desc->common_field.bit_length,
188 			  obj_desc->common_field.start_field_bit_offset,
189 			  obj_desc->common_field.base_byte_offset));
190 
191 	/* Lock entire transaction if requested */
192 
193 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
194 
195 	/* Read from the field */
196 
197 	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
198 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
199 
200       exit:
201 	if (ACPI_FAILURE(status)) {
202 		acpi_ut_remove_reference(buffer_desc);
203 	} else {
204 		*ret_buffer_desc = buffer_desc;
205 	}
206 
207 	return_ACPI_STATUS(status);
208 }
209 
210 /*******************************************************************************
211  *
212  * FUNCTION:    acpi_ex_write_data_to_field
213  *
214  * PARAMETERS:  source_desc         - Contains data to write
215  *              obj_desc            - The named field
216  *              result_desc         - Where the return value is returned, if any
217  *
218  * RETURN:      Status
219  *
220  * DESCRIPTION: Write to a named field
221  *
222  ******************************************************************************/
223 
224 acpi_status
225 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
226 			    union acpi_operand_object *obj_desc,
227 			    union acpi_operand_object **result_desc)
228 {
229 	acpi_status status;
230 	u32 length;
231 	void *buffer;
232 	union acpi_operand_object *buffer_desc;
233 	u32 function;
234 
235 	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
236 
237 	/* Parameter validation */
238 
239 	if (!source_desc || !obj_desc) {
240 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
241 	}
242 
243 	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
244 		/*
245 		 * If the buffer_field arguments have not been previously evaluated,
246 		 * evaluate them now and save the results.
247 		 */
248 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
249 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
250 			if (ACPI_FAILURE(status)) {
251 				return_ACPI_STATUS(status);
252 			}
253 		}
254 	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
255 		   (obj_desc->field.region_obj->region.space_id ==
256 		    ACPI_ADR_SPACE_SMBUS
257 		    || obj_desc->field.region_obj->region.space_id ==
258 		    ACPI_ADR_SPACE_GSBUS
259 		    || obj_desc->field.region_obj->region.space_id ==
260 		    ACPI_ADR_SPACE_IPMI)) {
261 		/*
262 		 * This is an SMBus, GSBus or IPMI write. We will bypass the entire field
263 		 * mechanism and handoff the buffer directly to the handler. For
264 		 * these address spaces, the buffer is bi-directional; on a write,
265 		 * return data is returned in the same buffer.
266 		 *
267 		 * Source must be a buffer of sufficient size:
268 		 * ACPI_SMBUS_BUFFER_SIZE, ACPI_GSBUS_BUFFER_SIZE, or ACPI_IPMI_BUFFER_SIZE.
269 		 *
270 		 * Note: SMBus and GSBus protocol type is passed in upper 16-bits of Function
271 		 */
272 		if (source_desc->common.type != ACPI_TYPE_BUFFER) {
273 			ACPI_ERROR((AE_INFO,
274 				    "SMBus/IPMI/GenericSerialBus write requires Buffer, found type %s",
275 				    acpi_ut_get_object_type_name(source_desc)));
276 
277 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
278 		}
279 
280 		if (obj_desc->field.region_obj->region.space_id ==
281 		    ACPI_ADR_SPACE_SMBUS) {
282 			length = ACPI_SMBUS_BUFFER_SIZE;
283 			function =
284 			    ACPI_WRITE | (obj_desc->field.attribute << 16);
285 		} else if (obj_desc->field.region_obj->region.space_id ==
286 			   ACPI_ADR_SPACE_GSBUS) {
287 			length = ACPI_GSBUS_BUFFER_SIZE;
288 			function =
289 			    ACPI_WRITE | (obj_desc->field.attribute << 16);
290 		} else {	/* IPMI */
291 
292 			length = ACPI_IPMI_BUFFER_SIZE;
293 			function = ACPI_WRITE;
294 		}
295 
296 		if (source_desc->buffer.length < length) {
297 			ACPI_ERROR((AE_INFO,
298 				    "SMBus/IPMI/GenericSerialBus write requires Buffer of length %u, found length %u",
299 				    length, source_desc->buffer.length));
300 
301 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
302 		}
303 
304 		/* Create the bi-directional buffer */
305 
306 		buffer_desc = acpi_ut_create_buffer_object(length);
307 		if (!buffer_desc) {
308 			return_ACPI_STATUS(AE_NO_MEMORY);
309 		}
310 
311 		buffer = buffer_desc->buffer.pointer;
312 		ACPI_MEMCPY(buffer, source_desc->buffer.pointer, length);
313 
314 		/* Lock entire transaction if requested */
315 
316 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
317 
318 		/*
319 		 * Perform the write (returns status and perhaps data in the
320 		 * same buffer)
321 		 */
322 		status = acpi_ex_access_region(obj_desc, 0,
323 					       (u64 *) buffer, function);
324 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
325 
326 		*result_desc = buffer_desc;
327 		return_ACPI_STATUS(status);
328 	}
329 
330 	/* Get a pointer to the data to be written */
331 
332 	switch (source_desc->common.type) {
333 	case ACPI_TYPE_INTEGER:
334 
335 		buffer = &source_desc->integer.value;
336 		length = sizeof(source_desc->integer.value);
337 		break;
338 
339 	case ACPI_TYPE_BUFFER:
340 
341 		buffer = source_desc->buffer.pointer;
342 		length = source_desc->buffer.length;
343 		break;
344 
345 	case ACPI_TYPE_STRING:
346 
347 		buffer = source_desc->string.pointer;
348 		length = source_desc->string.length;
349 		break;
350 
351 	default:
352 
353 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
354 	}
355 
356 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
357 			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
358 			  source_desc,
359 			  acpi_ut_get_type_name(source_desc->common.type),
360 			  source_desc->common.type, buffer, length));
361 
362 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
363 			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
364 			  obj_desc,
365 			  acpi_ut_get_type_name(obj_desc->common.type),
366 			  obj_desc->common.type,
367 			  obj_desc->common_field.bit_length,
368 			  obj_desc->common_field.start_field_bit_offset,
369 			  obj_desc->common_field.base_byte_offset));
370 
371 	/* Lock entire transaction if requested */
372 
373 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
374 
375 	/* Write to the field */
376 
377 	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
378 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
379 
380 	return_ACPI_STATUS(status);
381 }
382