1 /******************************************************************************
3 * Module Name: exprep - ACPI AML field prep utilities
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2016, Intel Corp.
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12 * modification, are permitted provided that the following conditions
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23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
26 * Alternatively, this software may be distributed under the terms of the
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44 #include <acpi/acpi.h>
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME("exprep")
54 /* Local prototypes */
56 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
57 u8 field_flags, u32 * return_byte_alignment);
59 #ifdef ACPI_UNDER_DEVELOPMENT
62 acpi_ex_generate_access(u32 field_bit_offset,
63 u32 field_bit_length, u32 region_length);
65 /*******************************************************************************
67 * FUNCTION: acpi_ex_generate_access
69 * PARAMETERS: field_bit_offset - Start of field within parent region/buffer
70 * field_bit_length - Length of field in bits
71 * region_length - Length of parent in bytes
73 * RETURN: Field granularity (8, 16, 32 or 64) and
74 * byte_alignment (1, 2, 3, or 4)
76 * DESCRIPTION: Generate an optimal access width for fields defined with the
79 * NOTE: Need to have the region_length in order to check for boundary
80 * conditions (end-of-region). However, the region_length is a deferred
81 * operation. Therefore, to complete this implementation, the generation
82 * of this access width must be deferred until the region length has
85 ******************************************************************************/
88 acpi_ex_generate_access(u32 field_bit_offset,
89 u32 field_bit_length, u32 region_length)
91 u32 field_byte_length;
92 u32 field_byte_offset;
93 u32 field_byte_end_offset;
94 u32 access_byte_width;
95 u32 field_start_offset;
97 u32 minimum_access_width = 0xFFFFFFFF;
98 u32 minimum_accesses = 0xFFFFFFFF;
101 ACPI_FUNCTION_TRACE(ex_generate_access);
103 /* Round Field start offset and length to "minimal" byte boundaries */
105 field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
107 field_byte_end_offset =
108 ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length + field_bit_offset, 8));
110 field_byte_length = field_byte_end_offset - field_byte_offset;
112 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
113 "Bit length %u, Bit offset %u\n",
114 field_bit_length, field_bit_offset));
116 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
117 "Byte Length %u, Byte Offset %u, End Offset %u\n",
118 field_byte_length, field_byte_offset,
119 field_byte_end_offset));
122 * Iterative search for the maximum access width that is both aligned
123 * and does not go beyond the end of the region
125 * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
127 for (access_byte_width = 1; access_byte_width <= 8;
128 access_byte_width <<= 1) {
130 * 1) Round end offset up to next access boundary and make sure that
131 * this does not go beyond the end of the parent region.
132 * 2) When the Access width is greater than the field_byte_length, we
133 * are done. (This does not optimize for the perfectly aligned
136 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
139 ACPI_ROUND_DOWN(field_byte_offset,
144 ACPI_ROUND_UP((field_byte_length +
149 accesses = field_end_offset - field_start_offset;
151 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
152 "AccessWidth %u end is within region\n",
155 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
156 "Field Start %u, Field End %u -- requires %u accesses\n",
157 field_start_offset, field_end_offset,
160 /* Single access is optimal */
163 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
164 "Entire field can be accessed "
165 "with one operation of size %u\n",
167 return_VALUE(access_byte_width);
171 * Fits in the region, but requires more than one read/write.
172 * try the next wider access on next iteration
174 if (accesses < minimum_accesses) {
175 minimum_accesses = accesses;
176 minimum_access_width = access_byte_width;
179 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
180 "AccessWidth %u end is NOT within region\n",
182 if (access_byte_width == 1) {
183 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
184 "Field goes beyond end-of-region!\n"));
186 /* Field does not fit in the region at all */
192 * This width goes beyond the end-of-region, back off to
195 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
196 "Backing off to previous optimal access width of %u\n",
197 minimum_access_width));
198 return_VALUE(minimum_access_width);
203 * Could not read/write field with one operation,
204 * just use max access width
206 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
207 "Cannot access field in one operation, using width 8\n"));
211 #endif /* ACPI_UNDER_DEVELOPMENT */
213 /*******************************************************************************
215 * FUNCTION: acpi_ex_decode_field_access
217 * PARAMETERS: obj_desc - Field object
218 * field_flags - Encoded fieldflags (contains access bits)
219 * return_byte_alignment - Where the byte alignment is returned
221 * RETURN: Field granularity (8, 16, 32 or 64) and
222 * byte_alignment (1, 2, 3, or 4)
224 * DESCRIPTION: Decode the access_type bits of a field definition.
226 ******************************************************************************/
229 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
230 u8 field_flags, u32 * return_byte_alignment)
236 ACPI_FUNCTION_TRACE(ex_decode_field_access);
238 access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
241 case AML_FIELD_ACCESS_ANY:
243 #ifdef ACPI_UNDER_DEVELOPMENT
245 acpi_ex_generate_access(obj_desc->common_field.
246 start_field_bit_offset,
247 obj_desc->common_field.bit_length,
249 /* Temp until we pass region_length as parameter */
251 bit_length = byte_alignment * 8;
258 case AML_FIELD_ACCESS_BYTE:
259 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */
265 case AML_FIELD_ACCESS_WORD:
271 case AML_FIELD_ACCESS_DWORD:
277 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */
285 /* Invalid field access type */
287 ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
292 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
294 * buffer_field access can be on any byte boundary, so the
295 * byte_alignment is always 1 byte -- regardless of any byte_alignment
296 * implied by the field access type.
301 *return_byte_alignment = byte_alignment;
302 return_UINT32(bit_length);
305 /*******************************************************************************
307 * FUNCTION: acpi_ex_prep_common_field_object
309 * PARAMETERS: obj_desc - The field object
310 * field_flags - Access, lock_rule, and update_rule.
311 * The format of a field_flag is described
312 * in the ACPI specification
313 * field_attribute - Special attributes (not used)
314 * field_bit_position - Field start position
315 * field_bit_length - Field length in number of bits
319 * DESCRIPTION: Initialize the areas of the field object that are common
320 * to the various types of fields. Note: This is very "sensitive"
321 * code because we are solving the general case for field
324 ******************************************************************************/
327 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
330 u32 field_bit_position, u32 field_bit_length)
332 u32 access_bit_width;
334 u32 nearest_byte_address;
336 ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
339 * Note: the structure being initialized is the
340 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
341 * area are initialized by this procedure.
343 obj_desc->common_field.field_flags = field_flags;
344 obj_desc->common_field.attribute = field_attribute;
345 obj_desc->common_field.bit_length = field_bit_length;
348 * Decode the access type so we can compute offsets. The access type gives
349 * two pieces of information - the width of each field access and the
350 * necessary byte_alignment (address granularity) of the access.
352 * For any_acc, the access_bit_width is the largest width that is both
353 * necessary and possible in an attempt to access the whole field in one
354 * I/O operation. However, for any_acc, the byte_alignment is always one
357 * For all Buffer Fields, the byte_alignment is always one byte.
359 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
360 * the same (equivalent) as the byte_alignment.
363 acpi_ex_decode_field_access(obj_desc, field_flags, &byte_alignment);
364 if (!access_bit_width) {
365 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
368 /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
370 obj_desc->common_field.access_byte_width = (u8)
371 ACPI_DIV_8(access_bit_width);
374 * base_byte_offset is the address of the start of the field within the
375 * region. It is the byte address of the first *datum* (field-width data
376 * unit) of the field. (i.e., the first datum that contains at least the
377 * first *bit* of the field.)
379 * Note: byte_alignment is always either equal to the access_bit_width or 8
380 * (Byte access), and it defines the addressing granularity of the parent
383 nearest_byte_address =
384 ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
385 obj_desc->common_field.base_byte_offset = (u32)
386 ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
389 * start_field_bit_offset is the offset of the first bit of the field within
392 obj_desc->common_field.start_field_bit_offset = (u8)
393 (field_bit_position -
394 ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
396 return_ACPI_STATUS(AE_OK);
399 /*******************************************************************************
401 * FUNCTION: acpi_ex_prep_field_value
403 * PARAMETERS: info - Contains all field creation info
407 * DESCRIPTION: Construct an object of type union acpi_operand_object with a
408 * subtype of def_field and connect it to the parent Node.
410 ******************************************************************************/
412 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
414 union acpi_operand_object *obj_desc;
415 union acpi_operand_object *second_desc = NULL;
417 u32 access_byte_width;
420 ACPI_FUNCTION_TRACE(ex_prep_field_value);
422 /* Parameter validation */
424 if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
425 if (!info->region_node) {
426 ACPI_ERROR((AE_INFO, "Null RegionNode"));
427 return_ACPI_STATUS(AE_AML_NO_OPERAND);
430 type = acpi_ns_get_type(info->region_node);
431 if (type != ACPI_TYPE_REGION) {
433 "Needed Region, found type 0x%X (%s)", type,
434 acpi_ut_get_type_name(type)));
436 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
440 /* Allocate a new field object */
442 obj_desc = acpi_ut_create_internal_object(info->field_type);
444 return_ACPI_STATUS(AE_NO_MEMORY);
447 /* Initialize areas of the object that are common to all fields */
449 obj_desc->common_field.node = info->field_node;
450 status = acpi_ex_prep_common_field_object(obj_desc,
453 info->field_bit_position,
454 info->field_bit_length);
455 if (ACPI_FAILURE(status)) {
456 acpi_ut_delete_object_desc(obj_desc);
457 return_ACPI_STATUS(status);
460 /* Initialize areas of the object that are specific to the field type */
462 switch (info->field_type) {
463 case ACPI_TYPE_LOCAL_REGION_FIELD:
465 obj_desc->field.region_obj =
466 acpi_ns_get_attached_object(info->region_node);
468 /* Fields specific to generic_serial_bus fields */
470 obj_desc->field.access_length = info->access_length;
472 if (info->connection_node) {
473 second_desc = info->connection_node->object;
474 if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
476 acpi_ds_get_buffer_arguments(second_desc);
477 if (ACPI_FAILURE(status)) {
478 acpi_ut_delete_object_desc(obj_desc);
479 return_ACPI_STATUS(status);
483 obj_desc->field.resource_buffer =
484 second_desc->buffer.pointer;
485 obj_desc->field.resource_length =
486 (u16)second_desc->buffer.length;
487 } else if (info->resource_buffer) {
488 obj_desc->field.resource_buffer = info->resource_buffer;
489 obj_desc->field.resource_length = info->resource_length;
492 obj_desc->field.pin_number_index = info->pin_number_index;
494 /* Allow full data read from EC address space */
496 if ((obj_desc->field.region_obj->region.space_id ==
498 && (obj_desc->common_field.bit_length > 8)) {
500 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
503 /* Maximum byte width supported is 255 */
505 if (access_byte_width < 256) {
506 obj_desc->common_field.access_byte_width =
507 (u8)access_byte_width;
510 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
511 "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
512 obj_desc->field.start_field_bit_offset,
513 obj_desc->field.base_byte_offset,
514 obj_desc->field.access_byte_width,
515 obj_desc->field.region_obj));
518 case ACPI_TYPE_LOCAL_BANK_FIELD:
520 obj_desc->bank_field.value = info->bank_value;
521 obj_desc->bank_field.region_obj =
522 acpi_ns_get_attached_object(info->region_node);
523 obj_desc->bank_field.bank_obj =
524 acpi_ns_get_attached_object(info->register_node);
526 /* An additional reference for the attached objects */
528 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
529 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
531 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
532 "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
533 obj_desc->bank_field.start_field_bit_offset,
534 obj_desc->bank_field.base_byte_offset,
535 obj_desc->field.access_byte_width,
536 obj_desc->bank_field.region_obj,
537 obj_desc->bank_field.bank_obj));
540 * Remember location in AML stream of the field unit
541 * opcode and operands -- since the bank_value
542 * operands must be evaluated.
544 second_desc = obj_desc->common.next_object;
545 second_desc->extra.aml_start =
546 ACPI_CAST_PTR(union acpi_parse_object,
547 info->data_register_node)->named.data;
548 second_desc->extra.aml_length =
549 ACPI_CAST_PTR(union acpi_parse_object,
550 info->data_register_node)->named.length;
554 case ACPI_TYPE_LOCAL_INDEX_FIELD:
556 /* Get the Index and Data registers */
558 obj_desc->index_field.index_obj =
559 acpi_ns_get_attached_object(info->register_node);
560 obj_desc->index_field.data_obj =
561 acpi_ns_get_attached_object(info->data_register_node);
563 if (!obj_desc->index_field.data_obj
564 || !obj_desc->index_field.index_obj) {
566 "Null Index Object during field prep"));
567 acpi_ut_delete_object_desc(obj_desc);
568 return_ACPI_STATUS(AE_AML_INTERNAL);
571 /* An additional reference for the attached objects */
573 acpi_ut_add_reference(obj_desc->index_field.data_obj);
574 acpi_ut_add_reference(obj_desc->index_field.index_obj);
577 * April 2006: Changed to match MS behavior
579 * The value written to the Index register is the byte offset of the
580 * target field in units of the granularity of the index_field
582 * Previously, the value was calculated as an index in terms of the
583 * width of the Data register, as below:
585 * obj_desc->index_field.Value = (u32)
586 * (Info->field_bit_position / ACPI_MUL_8 (
587 * obj_desc->Field.access_byte_width));
589 * February 2006: Tried value as a byte offset:
590 * obj_desc->index_field.Value = (u32)
591 * ACPI_DIV_8 (Info->field_bit_position);
593 obj_desc->index_field.value =
594 (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
595 obj_desc->index_field.
598 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
599 "IndexField: BitOff %X, Off %X, Value %X, "
600 "Gran %X, Index %p, Data %p\n",
601 obj_desc->index_field.start_field_bit_offset,
602 obj_desc->index_field.base_byte_offset,
603 obj_desc->index_field.value,
604 obj_desc->field.access_byte_width,
605 obj_desc->index_field.index_obj,
606 obj_desc->index_field.data_obj));
611 /* No other types should get here */
617 * Store the constructed descriptor (obj_desc) into the parent Node,
618 * preserving the current type of that named_obj.
621 acpi_ns_attach_object(info->field_node, obj_desc,
622 acpi_ns_get_type(info->field_node));
624 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
625 "Set NamedObj %p [%4.4s], ObjDesc %p\n",
627 acpi_ut_get_node_name(info->field_node), obj_desc));
629 /* Remove local reference to the object */
631 acpi_ut_remove_reference(obj_desc);
632 return_ACPI_STATUS(status);