xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision a09d2831)
1 /******************************************************************************
2  *
3  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2008, 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_IPMI)) {
104 		/*
105 		 * This is an SMBus or IPMI read. We must create a buffer to hold
106 		 * the data and then directly access the region handler.
107 		 *
108 		 * Note: Smbus protocol value is passed in upper 16-bits of Function
109 		 */
110 		if (obj_desc->field.region_obj->region.space_id ==
111 		    ACPI_ADR_SPACE_SMBUS) {
112 			length = ACPI_SMBUS_BUFFER_SIZE;
113 			function =
114 			    ACPI_READ | (obj_desc->field.attribute << 16);
115 		} else {	/* IPMI */
116 
117 			length = ACPI_IPMI_BUFFER_SIZE;
118 			function = ACPI_READ;
119 		}
120 
121 		buffer_desc = acpi_ut_create_buffer_object(length);
122 		if (!buffer_desc) {
123 			return_ACPI_STATUS(AE_NO_MEMORY);
124 		}
125 
126 		/* Lock entire transaction if requested */
127 
128 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
129 
130 		/* Call the region handler for the read */
131 
132 		status = acpi_ex_access_region(obj_desc, 0,
133 					       ACPI_CAST_PTR(acpi_integer,
134 							     buffer_desc->
135 							     buffer.pointer),
136 					       function);
137 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
138 		goto exit;
139 	}
140 
141 	/*
142 	 * Allocate a buffer for the contents of the field.
143 	 *
144 	 * If the field is larger than the size of an acpi_integer, create
145 	 * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
146 	 * the use of arithmetic operators on the returned value if the
147 	 * field size is equal or smaller than an Integer.
148 	 *
149 	 * Note: Field.length is in bits.
150 	 */
151 	length =
152 	    (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
153 	if (length > acpi_gbl_integer_byte_width) {
154 
155 		/* Field is too large for an Integer, create a Buffer instead */
156 
157 		buffer_desc = acpi_ut_create_buffer_object(length);
158 		if (!buffer_desc) {
159 			return_ACPI_STATUS(AE_NO_MEMORY);
160 		}
161 		buffer = buffer_desc->buffer.pointer;
162 	} else {
163 		/* Field will fit within an Integer (normal case) */
164 
165 		buffer_desc = acpi_ut_create_integer_object((u64) 0);
166 		if (!buffer_desc) {
167 			return_ACPI_STATUS(AE_NO_MEMORY);
168 		}
169 
170 		length = acpi_gbl_integer_byte_width;
171 		buffer = &buffer_desc->integer.value;
172 	}
173 
174 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
175 			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
176 			  obj_desc, obj_desc->common.type, buffer,
177 			  (u32) length));
178 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
179 			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
180 			  obj_desc->common_field.bit_length,
181 			  obj_desc->common_field.start_field_bit_offset,
182 			  obj_desc->common_field.base_byte_offset));
183 
184 	/* Lock entire transaction if requested */
185 
186 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
187 
188 	/* Read from the field */
189 
190 	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
191 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
192 
193       exit:
194 	if (ACPI_FAILURE(status)) {
195 		acpi_ut_remove_reference(buffer_desc);
196 	} else {
197 		*ret_buffer_desc = buffer_desc;
198 	}
199 
200 	return_ACPI_STATUS(status);
201 }
202 
203 /*******************************************************************************
204  *
205  * FUNCTION:    acpi_ex_write_data_to_field
206  *
207  * PARAMETERS:  source_desc         - Contains data to write
208  *              obj_desc            - The named field
209  *              result_desc         - Where the return value is returned, if any
210  *
211  * RETURN:      Status
212  *
213  * DESCRIPTION: Write to a named field
214  *
215  ******************************************************************************/
216 
217 acpi_status
218 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
219 			    union acpi_operand_object *obj_desc,
220 			    union acpi_operand_object **result_desc)
221 {
222 	acpi_status status;
223 	u32 length;
224 	void *buffer;
225 	union acpi_operand_object *buffer_desc;
226 	u32 function;
227 
228 	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
229 
230 	/* Parameter validation */
231 
232 	if (!source_desc || !obj_desc) {
233 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
234 	}
235 
236 	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
237 		/*
238 		 * If the buffer_field arguments have not been previously evaluated,
239 		 * evaluate them now and save the results.
240 		 */
241 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
242 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
243 			if (ACPI_FAILURE(status)) {
244 				return_ACPI_STATUS(status);
245 			}
246 		}
247 	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
248 		   (obj_desc->field.region_obj->region.space_id ==
249 		    ACPI_ADR_SPACE_SMBUS
250 		    || obj_desc->field.region_obj->region.space_id ==
251 		    ACPI_ADR_SPACE_IPMI)) {
252 		/*
253 		 * This is an SMBus or IPMI write. We will bypass the entire field
254 		 * mechanism and handoff the buffer directly to the handler. For
255 		 * these address spaces, the buffer is bi-directional; on a write,
256 		 * return data is returned in the same buffer.
257 		 *
258 		 * Source must be a buffer of sufficient size:
259 		 * ACPI_SMBUS_BUFFER_SIZE or ACPI_IPMI_BUFFER_SIZE.
260 		 *
261 		 * Note: SMBus protocol type is passed in upper 16-bits of Function
262 		 */
263 		if (source_desc->common.type != ACPI_TYPE_BUFFER) {
264 			ACPI_ERROR((AE_INFO,
265 				    "SMBus or IPMI write requires Buffer, found type %s",
266 				    acpi_ut_get_object_type_name(source_desc)));
267 
268 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
269 		}
270 
271 		if (obj_desc->field.region_obj->region.space_id ==
272 		    ACPI_ADR_SPACE_SMBUS) {
273 			length = ACPI_SMBUS_BUFFER_SIZE;
274 			function =
275 			    ACPI_WRITE | (obj_desc->field.attribute << 16);
276 		} else {	/* IPMI */
277 
278 			length = ACPI_IPMI_BUFFER_SIZE;
279 			function = ACPI_WRITE;
280 		}
281 
282 		if (source_desc->buffer.length < length) {
283 			ACPI_ERROR((AE_INFO,
284 				    "SMBus or IPMI write requires Buffer of length %X, found length %X",
285 				    length, source_desc->buffer.length));
286 
287 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
288 		}
289 
290 		/* Create the bi-directional buffer */
291 
292 		buffer_desc = acpi_ut_create_buffer_object(length);
293 		if (!buffer_desc) {
294 			return_ACPI_STATUS(AE_NO_MEMORY);
295 		}
296 
297 		buffer = buffer_desc->buffer.pointer;
298 		ACPI_MEMCPY(buffer, source_desc->buffer.pointer, length);
299 
300 		/* Lock entire transaction if requested */
301 
302 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
303 
304 		/*
305 		 * Perform the write (returns status and perhaps data in the
306 		 * same buffer)
307 		 */
308 		status = acpi_ex_access_region(obj_desc, 0,
309 					       (acpi_integer *) buffer,
310 					       function);
311 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
312 
313 		*result_desc = buffer_desc;
314 		return_ACPI_STATUS(status);
315 	}
316 
317 	/* Get a pointer to the data to be written */
318 
319 	switch (source_desc->common.type) {
320 	case ACPI_TYPE_INTEGER:
321 		buffer = &source_desc->integer.value;
322 		length = sizeof(source_desc->integer.value);
323 		break;
324 
325 	case ACPI_TYPE_BUFFER:
326 		buffer = source_desc->buffer.pointer;
327 		length = source_desc->buffer.length;
328 		break;
329 
330 	case ACPI_TYPE_STRING:
331 		buffer = source_desc->string.pointer;
332 		length = source_desc->string.length;
333 		break;
334 
335 	default:
336 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
337 	}
338 
339 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
340 			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
341 			  source_desc,
342 			  acpi_ut_get_type_name(source_desc->common.type),
343 			  source_desc->common.type, buffer, length));
344 
345 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
346 			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
347 			  obj_desc,
348 			  acpi_ut_get_type_name(obj_desc->common.type),
349 			  obj_desc->common.type,
350 			  obj_desc->common_field.bit_length,
351 			  obj_desc->common_field.start_field_bit_offset,
352 			  obj_desc->common_field.base_byte_offset));
353 
354 	/* Lock entire transaction if requested */
355 
356 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
357 
358 	/* Write to the field */
359 
360 	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
361 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
362 
363 	return_ACPI_STATUS(status);
364 }
365