xref: /openbmc/linux/drivers/acpi/acpica/exmisc.c (revision be2b81b5)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exmisc - ACPI AML (p-code) execution - specific opcodes
5  *
6  * Copyright (C) 2000 - 2022, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acinterp.h"
13 #include "amlcode.h"
14 
15 #define _COMPONENT          ACPI_EXECUTER
16 ACPI_MODULE_NAME("exmisc")
17 
18 /*******************************************************************************
19  *
20  * FUNCTION:    acpi_ex_get_object_reference
21  *
22  * PARAMETERS:  obj_desc            - Create a reference to this object
23  *              return_desc         - Where to store the reference
24  *              walk_state          - Current state
25  *
26  * RETURN:      Status
27  *
28  * DESCRIPTION: Obtain and return a "reference" to the target object
29  *              Common code for the ref_of_op and the cond_ref_of_op.
30  *
31  ******************************************************************************/
32 acpi_status
33 acpi_ex_get_object_reference(union acpi_operand_object *obj_desc,
34 			     union acpi_operand_object **return_desc,
35 			     struct acpi_walk_state *walk_state)
36 {
37 	union acpi_operand_object *reference_obj;
38 	union acpi_operand_object *referenced_obj;
39 
40 	ACPI_FUNCTION_TRACE_PTR(ex_get_object_reference, obj_desc);
41 
42 	*return_desc = NULL;
43 
44 	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
45 	case ACPI_DESC_TYPE_OPERAND:
46 
47 		if (obj_desc->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
48 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
49 		}
50 
51 		/*
52 		 * Must be a reference to a Local or Arg
53 		 */
54 		switch (obj_desc->reference.class) {
55 		case ACPI_REFCLASS_LOCAL:
56 		case ACPI_REFCLASS_ARG:
57 		case ACPI_REFCLASS_DEBUG:
58 
59 			/* The referenced object is the pseudo-node for the local/arg */
60 
61 			referenced_obj = obj_desc->reference.object;
62 			break;
63 
64 		default:
65 
66 			ACPI_ERROR((AE_INFO, "Invalid Reference Class 0x%2.2X",
67 				    obj_desc->reference.class));
68 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
69 		}
70 		break;
71 
72 	case ACPI_DESC_TYPE_NAMED:
73 		/*
74 		 * A named reference that has already been resolved to a Node
75 		 */
76 		referenced_obj = obj_desc;
77 		break;
78 
79 	default:
80 
81 		ACPI_ERROR((AE_INFO, "Invalid descriptor type 0x%X",
82 			    ACPI_GET_DESCRIPTOR_TYPE(obj_desc)));
83 		return_ACPI_STATUS(AE_TYPE);
84 	}
85 
86 	/* Create a new reference object */
87 
88 	reference_obj =
89 	    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
90 	if (!reference_obj) {
91 		return_ACPI_STATUS(AE_NO_MEMORY);
92 	}
93 
94 	reference_obj->reference.class = ACPI_REFCLASS_REFOF;
95 	reference_obj->reference.object = referenced_obj;
96 	*return_desc = reference_obj;
97 
98 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
99 			  "Object %p Type [%s], returning Reference %p\n",
100 			  obj_desc, acpi_ut_get_object_type_name(obj_desc),
101 			  *return_desc));
102 
103 	return_ACPI_STATUS(AE_OK);
104 }
105 
106 /*******************************************************************************
107  *
108  * FUNCTION:    acpi_ex_do_math_op
109  *
110  * PARAMETERS:  opcode              - AML opcode
111  *              integer0            - Integer operand #0
112  *              integer1            - Integer operand #1
113  *
114  * RETURN:      Integer result of the operation
115  *
116  * DESCRIPTION: Execute a math AML opcode. The purpose of having all of the
117  *              math functions here is to prevent a lot of pointer dereferencing
118  *              to obtain the operands.
119  *
120  ******************************************************************************/
121 
122 u64 acpi_ex_do_math_op(u16 opcode, u64 integer0, u64 integer1)
123 {
124 
125 	ACPI_FUNCTION_ENTRY();
126 
127 	switch (opcode) {
128 	case AML_ADD_OP:	/* Add (Integer0, Integer1, Result) */
129 
130 		return (integer0 + integer1);
131 
132 	case AML_BIT_AND_OP:	/* And (Integer0, Integer1, Result) */
133 
134 		return (integer0 & integer1);
135 
136 	case AML_BIT_NAND_OP:	/* NAnd (Integer0, Integer1, Result) */
137 
138 		return (~(integer0 & integer1));
139 
140 	case AML_BIT_OR_OP:	/* Or (Integer0, Integer1, Result) */
141 
142 		return (integer0 | integer1);
143 
144 	case AML_BIT_NOR_OP:	/* NOr (Integer0, Integer1, Result) */
145 
146 		return (~(integer0 | integer1));
147 
148 	case AML_BIT_XOR_OP:	/* XOr (Integer0, Integer1, Result) */
149 
150 		return (integer0 ^ integer1);
151 
152 	case AML_MULTIPLY_OP:	/* Multiply (Integer0, Integer1, Result) */
153 
154 		return (integer0 * integer1);
155 
156 	case AML_SHIFT_LEFT_OP:	/* shift_left (Operand, shift_count, Result) */
157 
158 		/*
159 		 * We need to check if the shiftcount is larger than the integer bit
160 		 * width since the behavior of this is not well-defined in the C language.
161 		 */
162 		if (integer1 >= acpi_gbl_integer_bit_width) {
163 			return (0);
164 		}
165 		return (integer0 << integer1);
166 
167 	case AML_SHIFT_RIGHT_OP:	/* shift_right (Operand, shift_count, Result) */
168 
169 		/*
170 		 * We need to check if the shiftcount is larger than the integer bit
171 		 * width since the behavior of this is not well-defined in the C language.
172 		 */
173 		if (integer1 >= acpi_gbl_integer_bit_width) {
174 			return (0);
175 		}
176 		return (integer0 >> integer1);
177 
178 	case AML_SUBTRACT_OP:	/* Subtract (Integer0, Integer1, Result) */
179 
180 		return (integer0 - integer1);
181 
182 	default:
183 
184 		return (0);
185 	}
186 }
187 
188 /*******************************************************************************
189  *
190  * FUNCTION:    acpi_ex_do_logical_numeric_op
191  *
192  * PARAMETERS:  opcode              - AML opcode
193  *              integer0            - Integer operand #0
194  *              integer1            - Integer operand #1
195  *              logical_result      - TRUE/FALSE result of the operation
196  *
197  * RETURN:      Status
198  *
199  * DESCRIPTION: Execute a logical "Numeric" AML opcode. For these Numeric
200  *              operators (LAnd and LOr), both operands must be integers.
201  *
202  *              Note: cleanest machine code seems to be produced by the code
203  *              below, rather than using statements of the form:
204  *                  Result = (Integer0 && Integer1);
205  *
206  ******************************************************************************/
207 
208 acpi_status
209 acpi_ex_do_logical_numeric_op(u16 opcode,
210 			      u64 integer0, u64 integer1, u8 *logical_result)
211 {
212 	acpi_status status = AE_OK;
213 	u8 local_result = FALSE;
214 
215 	ACPI_FUNCTION_TRACE(ex_do_logical_numeric_op);
216 
217 	switch (opcode) {
218 	case AML_LOGICAL_AND_OP:	/* LAnd (Integer0, Integer1) */
219 
220 		if (integer0 && integer1) {
221 			local_result = TRUE;
222 		}
223 		break;
224 
225 	case AML_LOGICAL_OR_OP:	/* LOr (Integer0, Integer1) */
226 
227 		if (integer0 || integer1) {
228 			local_result = TRUE;
229 		}
230 		break;
231 
232 	default:
233 
234 		ACPI_ERROR((AE_INFO,
235 			    "Invalid numeric logical opcode: %X", opcode));
236 		status = AE_AML_INTERNAL;
237 		break;
238 	}
239 
240 	/* Return the logical result and status */
241 
242 	*logical_result = local_result;
243 	return_ACPI_STATUS(status);
244 }
245 
246 /*******************************************************************************
247  *
248  * FUNCTION:    acpi_ex_do_logical_op
249  *
250  * PARAMETERS:  opcode              - AML opcode
251  *              operand0            - operand #0
252  *              operand1            - operand #1
253  *              logical_result      - TRUE/FALSE result of the operation
254  *
255  * RETURN:      Status
256  *
257  * DESCRIPTION: Execute a logical AML opcode. The purpose of having all of the
258  *              functions here is to prevent a lot of pointer dereferencing
259  *              to obtain the operands and to simplify the generation of the
260  *              logical value. For the Numeric operators (LAnd and LOr), both
261  *              operands must be integers. For the other logical operators,
262  *              operands can be any combination of Integer/String/Buffer. The
263  *              first operand determines the type to which the second operand
264  *              will be converted.
265  *
266  *              Note: cleanest machine code seems to be produced by the code
267  *              below, rather than using statements of the form:
268  *                  Result = (Operand0 == Operand1);
269  *
270  ******************************************************************************/
271 
272 acpi_status
273 acpi_ex_do_logical_op(u16 opcode,
274 		      union acpi_operand_object *operand0,
275 		      union acpi_operand_object *operand1, u8 * logical_result)
276 {
277 	union acpi_operand_object *local_operand1 = operand1;
278 	u64 integer0;
279 	u64 integer1;
280 	u32 length0;
281 	u32 length1;
282 	acpi_status status = AE_OK;
283 	u8 local_result = FALSE;
284 	int compare;
285 
286 	ACPI_FUNCTION_TRACE(ex_do_logical_op);
287 
288 	/*
289 	 * Convert the second operand if necessary. The first operand
290 	 * determines the type of the second operand, (See the Data Types
291 	 * section of the ACPI 3.0+ specification.)  Both object types are
292 	 * guaranteed to be either Integer/String/Buffer by the operand
293 	 * resolution mechanism.
294 	 */
295 	switch (operand0->common.type) {
296 	case ACPI_TYPE_INTEGER:
297 
298 		status = acpi_ex_convert_to_integer(operand1, &local_operand1,
299 						    ACPI_IMPLICIT_CONVERSION);
300 		break;
301 
302 	case ACPI_TYPE_STRING:
303 
304 		status =
305 		    acpi_ex_convert_to_string(operand1, &local_operand1,
306 					      ACPI_IMPLICIT_CONVERT_HEX);
307 		break;
308 
309 	case ACPI_TYPE_BUFFER:
310 
311 		status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
312 		break;
313 
314 	default:
315 
316 		ACPI_ERROR((AE_INFO,
317 			    "Invalid object type for logical operator: %X",
318 			    operand0->common.type));
319 		status = AE_AML_INTERNAL;
320 		break;
321 	}
322 
323 	if (ACPI_FAILURE(status)) {
324 		goto cleanup;
325 	}
326 
327 	/*
328 	 * Two cases: 1) Both Integers, 2) Both Strings or Buffers
329 	 */
330 	if (operand0->common.type == ACPI_TYPE_INTEGER) {
331 		/*
332 		 * 1) Both operands are of type integer
333 		 *    Note: local_operand1 may have changed above
334 		 */
335 		integer0 = operand0->integer.value;
336 		integer1 = local_operand1->integer.value;
337 
338 		switch (opcode) {
339 		case AML_LOGICAL_EQUAL_OP:	/* LEqual (Operand0, Operand1) */
340 
341 			if (integer0 == integer1) {
342 				local_result = TRUE;
343 			}
344 			break;
345 
346 		case AML_LOGICAL_GREATER_OP:	/* LGreater (Operand0, Operand1) */
347 
348 			if (integer0 > integer1) {
349 				local_result = TRUE;
350 			}
351 			break;
352 
353 		case AML_LOGICAL_LESS_OP:	/* LLess (Operand0, Operand1) */
354 
355 			if (integer0 < integer1) {
356 				local_result = TRUE;
357 			}
358 			break;
359 
360 		default:
361 
362 			ACPI_ERROR((AE_INFO,
363 				    "Invalid comparison opcode: %X", opcode));
364 			status = AE_AML_INTERNAL;
365 			break;
366 		}
367 	} else {
368 		/*
369 		 * 2) Both operands are Strings or both are Buffers
370 		 *    Note: Code below takes advantage of common Buffer/String
371 		 *          object fields. local_operand1 may have changed above. Use
372 		 *          memcmp to handle nulls in buffers.
373 		 */
374 		length0 = operand0->buffer.length;
375 		length1 = local_operand1->buffer.length;
376 
377 		/* Lexicographic compare: compare the data bytes */
378 
379 		compare = memcmp(operand0->buffer.pointer,
380 				 local_operand1->buffer.pointer,
381 				 (length0 > length1) ? length1 : length0);
382 
383 		switch (opcode) {
384 		case AML_LOGICAL_EQUAL_OP:	/* LEqual (Operand0, Operand1) */
385 
386 			/* Length and all bytes must be equal */
387 
388 			if ((length0 == length1) && (compare == 0)) {
389 
390 				/* Length and all bytes match ==> TRUE */
391 
392 				local_result = TRUE;
393 			}
394 			break;
395 
396 		case AML_LOGICAL_GREATER_OP:	/* LGreater (Operand0, Operand1) */
397 
398 			if (compare > 0) {
399 				local_result = TRUE;
400 				goto cleanup;	/* TRUE */
401 			}
402 			if (compare < 0) {
403 				goto cleanup;	/* FALSE */
404 			}
405 
406 			/* Bytes match (to shortest length), compare lengths */
407 
408 			if (length0 > length1) {
409 				local_result = TRUE;
410 			}
411 			break;
412 
413 		case AML_LOGICAL_LESS_OP:	/* LLess (Operand0, Operand1) */
414 
415 			if (compare > 0) {
416 				goto cleanup;	/* FALSE */
417 			}
418 			if (compare < 0) {
419 				local_result = TRUE;
420 				goto cleanup;	/* TRUE */
421 			}
422 
423 			/* Bytes match (to shortest length), compare lengths */
424 
425 			if (length0 < length1) {
426 				local_result = TRUE;
427 			}
428 			break;
429 
430 		default:
431 
432 			ACPI_ERROR((AE_INFO,
433 				    "Invalid comparison opcode: %X", opcode));
434 			status = AE_AML_INTERNAL;
435 			break;
436 		}
437 	}
438 
439 cleanup:
440 
441 	/* New object was created if implicit conversion performed - delete */
442 
443 	if (local_operand1 != operand1) {
444 		acpi_ut_remove_reference(local_operand1);
445 	}
446 
447 	/* Return the logical result and status */
448 
449 	*logical_result = local_result;
450 	return_ACPI_STATUS(status);
451 }
452