xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision fd589a8f)
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 
76 	ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
77 
78 	/* Parameter validation */
79 
80 	if (!obj_desc) {
81 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
82 	}
83 	if (!ret_buffer_desc) {
84 		return_ACPI_STATUS(AE_BAD_PARAMETER);
85 	}
86 
87 	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
88 		/*
89 		 * If the buffer_field arguments have not been previously evaluated,
90 		 * evaluate them now and save the results.
91 		 */
92 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
93 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
94 			if (ACPI_FAILURE(status)) {
95 				return_ACPI_STATUS(status);
96 			}
97 		}
98 	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
99 		   (obj_desc->field.region_obj->region.space_id ==
100 		    ACPI_ADR_SPACE_SMBUS)) {
101 		/*
102 		 * This is an SMBus read.  We must create a buffer to hold the data
103 		 * and directly access the region handler.
104 		 */
105 		buffer_desc =
106 		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
107 		if (!buffer_desc) {
108 			return_ACPI_STATUS(AE_NO_MEMORY);
109 		}
110 
111 		/* Lock entire transaction if requested */
112 
113 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
114 
115 		/*
116 		 * Perform the read.
117 		 * Note: Smbus protocol value is passed in upper 16-bits of Function
118 		 */
119 		status = acpi_ex_access_region(obj_desc, 0,
120 					       ACPI_CAST_PTR(acpi_integer,
121 							     buffer_desc->
122 							     buffer.pointer),
123 					       ACPI_READ | (obj_desc->field.
124 							    attribute << 16));
125 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
126 		goto exit;
127 	}
128 
129 	/*
130 	 * Allocate a buffer for the contents of the field.
131 	 *
132 	 * If the field is larger than the size of an acpi_integer, create
133 	 * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
134 	 * the use of arithmetic operators on the returned value if the
135 	 * field size is equal or smaller than an Integer.
136 	 *
137 	 * Note: Field.length is in bits.
138 	 */
139 	length =
140 	    (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
141 	if (length > acpi_gbl_integer_byte_width) {
142 
143 		/* Field is too large for an Integer, create a Buffer instead */
144 
145 		buffer_desc = acpi_ut_create_buffer_object(length);
146 		if (!buffer_desc) {
147 			return_ACPI_STATUS(AE_NO_MEMORY);
148 		}
149 		buffer = buffer_desc->buffer.pointer;
150 	} else {
151 		/* Field will fit within an Integer (normal case) */
152 
153 		buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
154 		if (!buffer_desc) {
155 			return_ACPI_STATUS(AE_NO_MEMORY);
156 		}
157 
158 		length = acpi_gbl_integer_byte_width;
159 		buffer_desc->integer.value = 0;
160 		buffer = &buffer_desc->integer.value;
161 	}
162 
163 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
164 			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
165 			  obj_desc, obj_desc->common.type, buffer,
166 			  (u32) length));
167 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
168 			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
169 			  obj_desc->common_field.bit_length,
170 			  obj_desc->common_field.start_field_bit_offset,
171 			  obj_desc->common_field.base_byte_offset));
172 
173 	/* Lock entire transaction if requested */
174 
175 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
176 
177 	/* Read from the field */
178 
179 	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
180 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
181 
182       exit:
183 	if (ACPI_FAILURE(status)) {
184 		acpi_ut_remove_reference(buffer_desc);
185 	} else {
186 		*ret_buffer_desc = buffer_desc;
187 	}
188 
189 	return_ACPI_STATUS(status);
190 }
191 
192 /*******************************************************************************
193  *
194  * FUNCTION:    acpi_ex_write_data_to_field
195  *
196  * PARAMETERS:  source_desc         - Contains data to write
197  *              obj_desc            - The named field
198  *              result_desc         - Where the return value is returned, if any
199  *
200  * RETURN:      Status
201  *
202  * DESCRIPTION: Write to a named field
203  *
204  ******************************************************************************/
205 
206 acpi_status
207 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
208 			    union acpi_operand_object *obj_desc,
209 			    union acpi_operand_object **result_desc)
210 {
211 	acpi_status status;
212 	u32 length;
213 	void *buffer;
214 	union acpi_operand_object *buffer_desc;
215 
216 	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
217 
218 	/* Parameter validation */
219 
220 	if (!source_desc || !obj_desc) {
221 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
222 	}
223 
224 	if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
225 		/*
226 		 * If the buffer_field arguments have not been previously evaluated,
227 		 * evaluate them now and save the results.
228 		 */
229 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
230 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
231 			if (ACPI_FAILURE(status)) {
232 				return_ACPI_STATUS(status);
233 			}
234 		}
235 	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
236 		   (obj_desc->field.region_obj->region.space_id ==
237 		    ACPI_ADR_SPACE_SMBUS)) {
238 		/*
239 		 * This is an SMBus write.  We will bypass the entire field mechanism
240 		 * and handoff the buffer directly to the handler.
241 		 *
242 		 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
243 		 */
244 		if (source_desc->common.type != ACPI_TYPE_BUFFER) {
245 			ACPI_ERROR((AE_INFO,
246 				    "SMBus write requires Buffer, found type %s",
247 				    acpi_ut_get_object_type_name(source_desc)));
248 
249 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
250 		}
251 
252 		if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
253 			ACPI_ERROR((AE_INFO,
254 				    "SMBus write requires Buffer of length %X, found length %X",
255 				    ACPI_SMBUS_BUFFER_SIZE,
256 				    source_desc->buffer.length));
257 
258 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
259 		}
260 
261 		buffer_desc =
262 		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
263 		if (!buffer_desc) {
264 			return_ACPI_STATUS(AE_NO_MEMORY);
265 		}
266 
267 		buffer = buffer_desc->buffer.pointer;
268 		ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
269 			    ACPI_SMBUS_BUFFER_SIZE);
270 
271 		/* Lock entire transaction if requested */
272 
273 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
274 
275 		/*
276 		 * Perform the write (returns status and perhaps data in the
277 		 * same buffer)
278 		 * Note: SMBus protocol type is passed in upper 16-bits of Function.
279 		 */
280 		status = acpi_ex_access_region(obj_desc, 0,
281 					       (acpi_integer *) buffer,
282 					       ACPI_WRITE | (obj_desc->field.
283 							     attribute << 16));
284 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
285 
286 		*result_desc = buffer_desc;
287 		return_ACPI_STATUS(status);
288 	}
289 
290 	/* Get a pointer to the data to be written */
291 
292 	switch (source_desc->common.type) {
293 	case ACPI_TYPE_INTEGER:
294 		buffer = &source_desc->integer.value;
295 		length = sizeof(source_desc->integer.value);
296 		break;
297 
298 	case ACPI_TYPE_BUFFER:
299 		buffer = source_desc->buffer.pointer;
300 		length = source_desc->buffer.length;
301 		break;
302 
303 	case ACPI_TYPE_STRING:
304 		buffer = source_desc->string.pointer;
305 		length = source_desc->string.length;
306 		break;
307 
308 	default:
309 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
310 	}
311 
312 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
313 			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
314 			  source_desc,
315 			  acpi_ut_get_type_name(source_desc->common.type),
316 			  source_desc->common.type, buffer, length));
317 
318 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
319 			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
320 			  obj_desc,
321 			  acpi_ut_get_type_name(obj_desc->common.type),
322 			  obj_desc->common.type,
323 			  obj_desc->common_field.bit_length,
324 			  obj_desc->common_field.start_field_bit_offset,
325 			  obj_desc->common_field.base_byte_offset));
326 
327 	/* Lock entire transaction if requested */
328 
329 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
330 
331 	/* Write to the field */
332 
333 	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
334 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
335 
336 	return_ACPI_STATUS(status);
337 }
338