xref: /openbmc/linux/drivers/acpi/acpica/exfield.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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 (ACPI_GET_OBJECT_TYPE(obj_desc) == 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
99 	    if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
100 		&& (obj_desc->field.region_obj->region.space_id ==
101 		    ACPI_ADR_SPACE_SMBUS)) {
102 		/*
103 		 * This is an SMBus read.  We must create a buffer to hold the data
104 		 * and directly access the region handler.
105 		 */
106 		buffer_desc =
107 		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
108 		if (!buffer_desc) {
109 			return_ACPI_STATUS(AE_NO_MEMORY);
110 		}
111 
112 		/* Lock entire transaction if requested */
113 
114 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
115 
116 		/*
117 		 * Perform the read.
118 		 * Note: Smbus protocol value is passed in upper 16-bits of Function
119 		 */
120 		status = acpi_ex_access_region(obj_desc, 0,
121 					       ACPI_CAST_PTR(acpi_integer,
122 							     buffer_desc->
123 							     buffer.pointer),
124 					       ACPI_READ | (obj_desc->field.
125 							    attribute << 16));
126 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
127 		goto exit;
128 	}
129 
130 	/*
131 	 * Allocate a buffer for the contents of the field.
132 	 *
133 	 * If the field is larger than the size of an acpi_integer, create
134 	 * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
135 	 * the use of arithmetic operators on the returned value if the
136 	 * field size is equal or smaller than an Integer.
137 	 *
138 	 * Note: Field.length is in bits.
139 	 */
140 	length =
141 	    (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
142 	if (length > acpi_gbl_integer_byte_width) {
143 
144 		/* Field is too large for an Integer, create a Buffer instead */
145 
146 		buffer_desc = acpi_ut_create_buffer_object(length);
147 		if (!buffer_desc) {
148 			return_ACPI_STATUS(AE_NO_MEMORY);
149 		}
150 		buffer = buffer_desc->buffer.pointer;
151 	} else {
152 		/* Field will fit within an Integer (normal case) */
153 
154 		buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
155 		if (!buffer_desc) {
156 			return_ACPI_STATUS(AE_NO_MEMORY);
157 		}
158 
159 		length = acpi_gbl_integer_byte_width;
160 		buffer_desc->integer.value = 0;
161 		buffer = &buffer_desc->integer.value;
162 	}
163 
164 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
165 			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
166 			  obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
167 			  (u32) length));
168 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
169 			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
170 			  obj_desc->common_field.bit_length,
171 			  obj_desc->common_field.start_field_bit_offset,
172 			  obj_desc->common_field.base_byte_offset));
173 
174 	/* Lock entire transaction if requested */
175 
176 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
177 
178 	/* Read from the field */
179 
180 	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
181 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
182 
183       exit:
184 	if (ACPI_FAILURE(status)) {
185 		acpi_ut_remove_reference(buffer_desc);
186 	} else {
187 		*ret_buffer_desc = buffer_desc;
188 	}
189 
190 	return_ACPI_STATUS(status);
191 }
192 
193 /*******************************************************************************
194  *
195  * FUNCTION:    acpi_ex_write_data_to_field
196  *
197  * PARAMETERS:  source_desc         - Contains data to write
198  *              obj_desc            - The named field
199  *              result_desc         - Where the return value is returned, if any
200  *
201  * RETURN:      Status
202  *
203  * DESCRIPTION: Write to a named field
204  *
205  ******************************************************************************/
206 
207 acpi_status
208 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
209 			    union acpi_operand_object *obj_desc,
210 			    union acpi_operand_object **result_desc)
211 {
212 	acpi_status status;
213 	u32 length;
214 	void *buffer;
215 	union acpi_operand_object *buffer_desc;
216 
217 	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
218 
219 	/* Parameter validation */
220 
221 	if (!source_desc || !obj_desc) {
222 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
223 	}
224 
225 	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
226 		/*
227 		 * If the buffer_field arguments have not been previously evaluated,
228 		 * evaluate them now and save the results.
229 		 */
230 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
231 			status = acpi_ds_get_buffer_field_arguments(obj_desc);
232 			if (ACPI_FAILURE(status)) {
233 				return_ACPI_STATUS(status);
234 			}
235 		}
236 	} else
237 	    if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
238 		&& (obj_desc->field.region_obj->region.space_id ==
239 		    ACPI_ADR_SPACE_SMBUS)) {
240 		/*
241 		 * This is an SMBus write.  We will bypass the entire field mechanism
242 		 * and handoff the buffer directly to the handler.
243 		 *
244 		 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
245 		 */
246 		if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
247 			ACPI_ERROR((AE_INFO,
248 				    "SMBus write requires Buffer, found type %s",
249 				    acpi_ut_get_object_type_name(source_desc)));
250 
251 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
252 		}
253 
254 		if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
255 			ACPI_ERROR((AE_INFO,
256 				    "SMBus write requires Buffer of length %X, found length %X",
257 				    ACPI_SMBUS_BUFFER_SIZE,
258 				    source_desc->buffer.length));
259 
260 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
261 		}
262 
263 		buffer_desc =
264 		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
265 		if (!buffer_desc) {
266 			return_ACPI_STATUS(AE_NO_MEMORY);
267 		}
268 
269 		buffer = buffer_desc->buffer.pointer;
270 		ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
271 			    ACPI_SMBUS_BUFFER_SIZE);
272 
273 		/* Lock entire transaction if requested */
274 
275 		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
276 
277 		/*
278 		 * Perform the write (returns status and perhaps data in the
279 		 * same buffer)
280 		 * Note: SMBus protocol type is passed in upper 16-bits of Function.
281 		 */
282 		status = acpi_ex_access_region(obj_desc, 0,
283 					       (acpi_integer *) buffer,
284 					       ACPI_WRITE | (obj_desc->field.
285 							     attribute << 16));
286 		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
287 
288 		*result_desc = buffer_desc;
289 		return_ACPI_STATUS(status);
290 	}
291 
292 	/* Get a pointer to the data to be written */
293 
294 	switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
295 	case ACPI_TYPE_INTEGER:
296 		buffer = &source_desc->integer.value;
297 		length = sizeof(source_desc->integer.value);
298 		break;
299 
300 	case ACPI_TYPE_BUFFER:
301 		buffer = source_desc->buffer.pointer;
302 		length = source_desc->buffer.length;
303 		break;
304 
305 	case ACPI_TYPE_STRING:
306 		buffer = source_desc->string.pointer;
307 		length = source_desc->string.length;
308 		break;
309 
310 	default:
311 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
312 	}
313 
314 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
315 			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
316 			  source_desc,
317 			  acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
318 						(source_desc)),
319 			  ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));
320 
321 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
322 			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
323 			  obj_desc,
324 			  acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
325 			  ACPI_GET_OBJECT_TYPE(obj_desc),
326 			  obj_desc->common_field.bit_length,
327 			  obj_desc->common_field.start_field_bit_offset,
328 			  obj_desc->common_field.base_byte_offset));
329 
330 	/* Lock entire transaction if requested */
331 
332 	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
333 
334 	/* Write to the field */
335 
336 	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
337 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
338 
339 	return_ACPI_STATUS(status);
340 }
341