xref: /openbmc/linux/drivers/acpi/acpica/exutils.c (revision 842ed298)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exutils - interpreter/scanner utilities
5  *
6  * Copyright (C) 2000 - 2020, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 /*
11  * DEFINE_AML_GLOBALS is tested in amlcode.h
12  * to determine whether certain global names should be "defined" or only
13  * "declared" in the current compilation. This enhances maintainability
14  * by enabling a single header file to embody all knowledge of the names
15  * in question.
16  *
17  * Exactly one module of any executable should #define DEFINE_GLOBALS
18  * before #including the header files which use this convention. The
19  * names in question will be defined and initialized in that module,
20  * and declared as extern in all other modules which #include those
21  * header files.
22  */
23 
24 #define DEFINE_AML_GLOBALS
25 
26 #include <acpi/acpi.h>
27 #include "accommon.h"
28 #include "acinterp.h"
29 #include "amlcode.h"
30 
31 #define _COMPONENT          ACPI_EXECUTER
32 ACPI_MODULE_NAME("exutils")
33 
34 /* Local prototypes */
35 static u32 acpi_ex_digits_needed(u64 value, u32 base);
36 
37 /*******************************************************************************
38  *
39  * FUNCTION:    acpi_ex_enter_interpreter
40  *
41  * PARAMETERS:  None
42  *
43  * RETURN:      None
44  *
45  * DESCRIPTION: Enter the interpreter execution region. Failure to enter
46  *              the interpreter region is a fatal system error. Used in
47  *              conjunction with exit_interpreter.
48  *
49  ******************************************************************************/
50 
51 void acpi_ex_enter_interpreter(void)
52 {
53 	acpi_status status;
54 
55 	ACPI_FUNCTION_TRACE(ex_enter_interpreter);
56 
57 	status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
58 	if (ACPI_FAILURE(status)) {
59 		ACPI_ERROR((AE_INFO,
60 			    "Could not acquire AML Interpreter mutex"));
61 	}
62 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
63 	if (ACPI_FAILURE(status)) {
64 		ACPI_ERROR((AE_INFO, "Could not acquire AML Namespace mutex"));
65 	}
66 
67 	return_VOID;
68 }
69 
70 /*******************************************************************************
71  *
72  * FUNCTION:    acpi_ex_exit_interpreter
73  *
74  * PARAMETERS:  None
75  *
76  * RETURN:      None
77  *
78  * DESCRIPTION: Exit the interpreter execution region. This is the top level
79  *              routine used to exit the interpreter when all processing has
80  *              been completed, or when the method blocks.
81  *
82  * Cases where the interpreter is unlocked internally:
83  *      1) Method will be blocked on a Sleep() AML opcode
84  *      2) Method will be blocked on an Acquire() AML opcode
85  *      3) Method will be blocked on a Wait() AML opcode
86  *      4) Method will be blocked to acquire the global lock
87  *      5) Method will be blocked waiting to execute a serialized control
88  *          method that is currently executing
89  *      6) About to invoke a user-installed opregion handler
90  *
91  ******************************************************************************/
92 
93 void acpi_ex_exit_interpreter(void)
94 {
95 	acpi_status status;
96 
97 	ACPI_FUNCTION_TRACE(ex_exit_interpreter);
98 
99 	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
100 	if (ACPI_FAILURE(status)) {
101 		ACPI_ERROR((AE_INFO, "Could not release AML Namespace mutex"));
102 	}
103 	status = acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
104 	if (ACPI_FAILURE(status)) {
105 		ACPI_ERROR((AE_INFO,
106 			    "Could not release AML Interpreter mutex"));
107 	}
108 
109 	return_VOID;
110 }
111 
112 /*******************************************************************************
113  *
114  * FUNCTION:    acpi_ex_truncate_for32bit_table
115  *
116  * PARAMETERS:  obj_desc        - Object to be truncated
117  *
118  * RETURN:      TRUE if a truncation was performed, FALSE otherwise.
119  *
120  * DESCRIPTION: Truncate an ACPI Integer to 32 bits if the execution mode is
121  *              32-bit, as determined by the revision of the DSDT.
122  *
123  ******************************************************************************/
124 
125 u8 acpi_ex_truncate_for32bit_table(union acpi_operand_object *obj_desc)
126 {
127 
128 	ACPI_FUNCTION_ENTRY();
129 
130 	/*
131 	 * Object must be a valid number and we must be executing
132 	 * a control method. Object could be NS node for AML_INT_NAMEPATH_OP.
133 	 */
134 	if ((!obj_desc) ||
135 	    (ACPI_GET_DESCRIPTOR_TYPE(obj_desc) != ACPI_DESC_TYPE_OPERAND) ||
136 	    (obj_desc->common.type != ACPI_TYPE_INTEGER)) {
137 		return (FALSE);
138 	}
139 
140 	if ((acpi_gbl_integer_byte_width == 4) &&
141 	    (obj_desc->integer.value > (u64)ACPI_UINT32_MAX)) {
142 		/*
143 		 * We are executing in a 32-bit ACPI table. Truncate
144 		 * the value to 32 bits by zeroing out the upper 32-bit field
145 		 */
146 		obj_desc->integer.value &= (u64)ACPI_UINT32_MAX;
147 		return (TRUE);
148 	}
149 
150 	return (FALSE);
151 }
152 
153 /*******************************************************************************
154  *
155  * FUNCTION:    acpi_ex_acquire_global_lock
156  *
157  * PARAMETERS:  field_flags           - Flags with Lock rule:
158  *                                      always_lock or never_lock
159  *
160  * RETURN:      None
161  *
162  * DESCRIPTION: Obtain the ACPI hardware Global Lock, only if the field
163  *              flags specify that it is to be obtained before field access.
164  *
165  ******************************************************************************/
166 
167 void acpi_ex_acquire_global_lock(u32 field_flags)
168 {
169 	acpi_status status;
170 
171 	ACPI_FUNCTION_TRACE(ex_acquire_global_lock);
172 
173 	/* Only use the lock if the always_lock bit is set */
174 
175 	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
176 		return_VOID;
177 	}
178 
179 	/* Attempt to get the global lock, wait forever */
180 
181 	status = acpi_ex_acquire_mutex_object(ACPI_WAIT_FOREVER,
182 					      acpi_gbl_global_lock_mutex,
183 					      acpi_os_get_thread_id());
184 
185 	if (ACPI_FAILURE(status)) {
186 		ACPI_EXCEPTION((AE_INFO, status,
187 				"Could not acquire Global Lock"));
188 	}
189 
190 	return_VOID;
191 }
192 
193 /*******************************************************************************
194  *
195  * FUNCTION:    acpi_ex_release_global_lock
196  *
197  * PARAMETERS:  field_flags           - Flags with Lock rule:
198  *                                      always_lock or never_lock
199  *
200  * RETURN:      None
201  *
202  * DESCRIPTION: Release the ACPI hardware Global Lock
203  *
204  ******************************************************************************/
205 
206 void acpi_ex_release_global_lock(u32 field_flags)
207 {
208 	acpi_status status;
209 
210 	ACPI_FUNCTION_TRACE(ex_release_global_lock);
211 
212 	/* Only use the lock if the always_lock bit is set */
213 
214 	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
215 		return_VOID;
216 	}
217 
218 	/* Release the global lock */
219 
220 	status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
221 	if (ACPI_FAILURE(status)) {
222 
223 		/* Report the error, but there isn't much else we can do */
224 
225 		ACPI_EXCEPTION((AE_INFO, status,
226 				"Could not release Global Lock"));
227 	}
228 
229 	return_VOID;
230 }
231 
232 /*******************************************************************************
233  *
234  * FUNCTION:    acpi_ex_digits_needed
235  *
236  * PARAMETERS:  value           - Value to be represented
237  *              base            - Base of representation
238  *
239  * RETURN:      The number of digits.
240  *
241  * DESCRIPTION: Calculate the number of digits needed to represent the Value
242  *              in the given Base (Radix)
243  *
244  ******************************************************************************/
245 
246 static u32 acpi_ex_digits_needed(u64 value, u32 base)
247 {
248 	u32 num_digits;
249 	u64 current_value;
250 
251 	ACPI_FUNCTION_TRACE(ex_digits_needed);
252 
253 	/* u64 is unsigned, so we don't worry about a '-' prefix */
254 
255 	if (value == 0) {
256 		return_UINT32(1);
257 	}
258 
259 	current_value = value;
260 	num_digits = 0;
261 
262 	/* Count the digits in the requested base */
263 
264 	while (current_value) {
265 		(void)acpi_ut_short_divide(current_value, base, &current_value,
266 					   NULL);
267 		num_digits++;
268 	}
269 
270 	return_UINT32(num_digits);
271 }
272 
273 /*******************************************************************************
274  *
275  * FUNCTION:    acpi_ex_eisa_id_to_string
276  *
277  * PARAMETERS:  out_string      - Where to put the converted string (8 bytes)
278  *              compressed_id   - EISAID to be converted
279  *
280  * RETURN:      None
281  *
282  * DESCRIPTION: Convert a numeric EISAID to string representation. Return
283  *              buffer must be large enough to hold the string. The string
284  *              returned is always exactly of length ACPI_EISAID_STRING_SIZE
285  *              (includes null terminator). The EISAID is always 32 bits.
286  *
287  ******************************************************************************/
288 
289 void acpi_ex_eisa_id_to_string(char *out_string, u64 compressed_id)
290 {
291 	u32 swapped_id;
292 
293 	ACPI_FUNCTION_ENTRY();
294 
295 	/* The EISAID should be a 32-bit integer */
296 
297 	if (compressed_id > ACPI_UINT32_MAX) {
298 		ACPI_WARNING((AE_INFO,
299 			      "Expected EISAID is larger than 32 bits: "
300 			      "0x%8.8X%8.8X, truncating",
301 			      ACPI_FORMAT_UINT64(compressed_id)));
302 	}
303 
304 	/* Swap ID to big-endian to get contiguous bits */
305 
306 	swapped_id = acpi_ut_dword_byte_swap((u32)compressed_id);
307 
308 	/* First 3 bytes are uppercase letters. Next 4 bytes are hexadecimal */
309 
310 	out_string[0] =
311 	    (char)(0x40 + (((unsigned long)swapped_id >> 26) & 0x1F));
312 	out_string[1] = (char)(0x40 + ((swapped_id >> 21) & 0x1F));
313 	out_string[2] = (char)(0x40 + ((swapped_id >> 16) & 0x1F));
314 	out_string[3] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 12);
315 	out_string[4] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 8);
316 	out_string[5] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 4);
317 	out_string[6] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 0);
318 	out_string[7] = 0;
319 }
320 
321 /*******************************************************************************
322  *
323  * FUNCTION:    acpi_ex_integer_to_string
324  *
325  * PARAMETERS:  out_string      - Where to put the converted string. At least
326  *                                21 bytes are needed to hold the largest
327  *                                possible 64-bit integer.
328  *              value           - Value to be converted
329  *
330  * RETURN:      Converted string in out_string
331  *
332  * DESCRIPTION: Convert a 64-bit integer to decimal string representation.
333  *              Assumes string buffer is large enough to hold the string. The
334  *              largest string is (ACPI_MAX64_DECIMAL_DIGITS + 1).
335  *
336  ******************************************************************************/
337 
338 void acpi_ex_integer_to_string(char *out_string, u64 value)
339 {
340 	u32 count;
341 	u32 digits_needed;
342 	u32 remainder;
343 
344 	ACPI_FUNCTION_ENTRY();
345 
346 	digits_needed = acpi_ex_digits_needed(value, 10);
347 	out_string[digits_needed] = 0;
348 
349 	for (count = digits_needed; count > 0; count--) {
350 		(void)acpi_ut_short_divide(value, 10, &value, &remainder);
351 		out_string[count - 1] = (char)('0' + remainder);
352 	}
353 }
354 
355 /*******************************************************************************
356  *
357  * FUNCTION:    acpi_ex_pci_cls_to_string
358  *
359  * PARAMETERS:  out_string      - Where to put the converted string (7 bytes)
360  *              class_code      - PCI class code to be converted (3 bytes)
361  *
362  * RETURN:      Converted string in out_string
363  *
364  * DESCRIPTION: Convert 3-bytes PCI class code to string representation.
365  *              Return buffer must be large enough to hold the string. The
366  *              string returned is always exactly of length
367  *              ACPI_PCICLS_STRING_SIZE (includes null terminator).
368  *
369  ******************************************************************************/
370 
371 void acpi_ex_pci_cls_to_string(char *out_string, u8 class_code[3])
372 {
373 
374 	ACPI_FUNCTION_ENTRY();
375 
376 	/* All 3 bytes are hexadecimal */
377 
378 	out_string[0] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 4);
379 	out_string[1] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 0);
380 	out_string[2] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 4);
381 	out_string[3] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 0);
382 	out_string[4] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 4);
383 	out_string[5] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 0);
384 	out_string[6] = 0;
385 }
386 
387 /*******************************************************************************
388  *
389  * FUNCTION:    acpi_is_valid_space_id
390  *
391  * PARAMETERS:  space_id            - ID to be validated
392  *
393  * RETURN:      TRUE if space_id is a valid/supported ID.
394  *
395  * DESCRIPTION: Validate an operation region space_ID.
396  *
397  ******************************************************************************/
398 
399 u8 acpi_is_valid_space_id(u8 space_id)
400 {
401 
402 	if ((space_id >= ACPI_NUM_PREDEFINED_REGIONS) &&
403 	    (space_id < ACPI_USER_REGION_BEGIN) &&
404 	    (space_id != ACPI_ADR_SPACE_DATA_TABLE) &&
405 	    (space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
406 		return (FALSE);
407 	}
408 
409 	return (TRUE);
410 }
411