summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/acpica/utstrtoul64.c
blob: f42be01d99fdd48d22edbbf9ce56c275e949e253 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
/*******************************************************************************
 *
 * Module Name: utstrtoul64 - string to 64-bit integer support
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2017, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"

/*******************************************************************************
 *
 * The functions in this module satisfy the need for 64-bit string-to-integer
 * conversions on both 32-bit and 64-bit platforms.
 *
 ******************************************************************************/

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utstrtoul64")

/* Local prototypes */
static u64 acpi_ut_strtoul_base10(char *string, u32 flags);

static u64 acpi_ut_strtoul_base16(char *string, u32 flags);

/*******************************************************************************
 *
 * String conversion rules as written in the ACPI specification. The error
 * conditions and behavior are different depending on the type of conversion.
 *
 *
 * Implicit data type conversion: string-to-integer
 * --------------------------------------------------
 *
 * Base is always 16. This is the ACPI_STRTOUL_BASE16 case.
 *
 * Example:
 *      Add ("BA98", Arg0, Local0)
 *
 * The integer is initialized to the value zero.
 * The ASCII string is interpreted as a hexadecimal constant.
 *
 *  1)  A "0x" prefix is not allowed. However, ACPICA allows this for
 *      compatibility with previous ACPICA. (NO ERROR)
 *
 *  2)  Terminates when the size of an integer is reached (32 or 64 bits).
 *      (NO ERROR)
 *
 *  3)  The first non-hex character terminates the conversion without error.
 *      (NO ERROR)
 *
 *  4)  Conversion of a null (zero-length) string to an integer is not
 *      allowed. However, ACPICA allows this for compatibility with previous
 *      ACPICA. This conversion returns the value 0. (NO ERROR)
 *
 *
 * Explicit data type conversion:  to_integer() with string operand
 * ---------------------------------------------------------------
 *
 * Base is either 10 (default) or 16 (with 0x prefix)
 *
 * Examples:
 *      to_integer ("1000")
 *      to_integer ("0xABCD")
 *
 *  1)  Can be (must be) either a decimal or hexadecimal numeric string.
 *      A hex value must be prefixed by "0x" or it is interpreted as a decimal.
 *
 *  2)  The value must not exceed the maximum of an integer value. ACPI spec
 *      states the behavior is "unpredictable", so ACPICA matches the behavior
 *      of the implicit conversion case.(NO ERROR)
 *
 *  3)  Behavior on the first non-hex character is not specified by the ACPI
 *      spec, so ACPICA matches the behavior of the implicit conversion case
 *      and terminates. (NO ERROR)
 *
 *  4)  A null (zero-length) string is illegal.
 *      However, ACPICA allows this for compatibility with previous ACPICA.
 *      This conversion returns the value 0. (NO ERROR)
 *
 ******************************************************************************/

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_strtoul64
 *
 * PARAMETERS:  string                  - Null terminated input string
 *              flags                   - Conversion info, see below
 *              return_value            - Where the converted integer is
 *                                        returned
 *
 * RETURN:      Status and Converted value
 *
 * DESCRIPTION: Convert a string into an unsigned value. Performs either a
 *              32-bit or 64-bit conversion, depending on the input integer
 *              size in Flags (often the current mode of the interpreter).
 *
 * Values for Flags:
 *      ACPI_STRTOUL_32BIT      - Max integer value is 32 bits
 *      ACPI_STRTOUL_64BIT      - Max integer value is 64 bits
 *      ACPI_STRTOUL_BASE16     - Input string is hexadecimal. Default
 *                                is 10/16 based on string prefix (0x).
 *
 * NOTES:
 *   Negative numbers are not supported, as they are not supported by ACPI.
 *
 *   Supports only base 16 or base 10 strings/values. Does not
 *   support Octal strings, as these are not supported by ACPI.
 *
 * Current users of this support:
 *
 *  interpreter - Implicit and explicit conversions, GPE method names
 *  debugger    - Command line input string conversion
 *  iASL        - Main parser, conversion of constants to integers
 *  iASL        - Data Table Compiler parser (constant math expressions)
 *  iASL        - Preprocessor (constant math expressions)
 *  acpi_dump   - Input table addresses
 *  acpi_exec   - Testing of the acpi_ut_strtoul64 function
 *
 * Note concerning callers:
 *   acpi_gbl_integer_byte_width can be used to set the 32/64 limit. If used,
 *   this global should be set to the proper width. For the core ACPICA code,
 *   this width depends on the DSDT version. For iASL, the default byte
 *   width is always 8 for the parser, but error checking is performed later
 *   to flag cases where a 64-bit constant is defined in a 32-bit DSDT/SSDT.
 *
 ******************************************************************************/

acpi_status acpi_ut_strtoul64(char *string, u32 flags, u64 *return_value)
{
	acpi_status status = AE_OK;
	u32 base;

	ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string);

	/* Parameter validation */

	if (!string || !return_value) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	*return_value = 0;

	/* Check for zero-length string, returns 0 */

	if (*string == 0) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Skip over any white space at start of string */

	while (isspace((int)*string)) {
		string++;
	}

	/* End of string? return 0 */

	if (*string == 0) {
		return_ACPI_STATUS(AE_OK);
	}

	/*
	 * 1) The "0x" prefix indicates base 16. Per the ACPI specification,
	 * the "0x" prefix is only allowed for implicit (non-strict) conversions.
	 * However, we always allow it for compatibility with older ACPICA.
	 */
	if ((*string == ACPI_ASCII_ZERO) &&
	    (tolower((int)*(string + 1)) == 'x')) {
		string += 2;	/* Go past the 0x */
		if (*string == 0) {
			return_ACPI_STATUS(AE_OK);	/* Return value 0 */
		}

		base = 16;
	}

	/* 2) Force to base 16 (implicit conversion case) */

	else if (flags & ACPI_STRTOUL_BASE16) {
		base = 16;
	}

	/* 3) Default fallback is to Base 10 */

	else {
		base = 10;
	}

	/* Skip all leading zeros */

	while (*string == ACPI_ASCII_ZERO) {
		string++;
		if (*string == 0) {
			return_ACPI_STATUS(AE_OK);	/* Return value 0 */
		}
	}

	/* Perform the base 16 or 10 conversion */

	if (base == 16) {
		*return_value = acpi_ut_strtoul_base16(string, flags);
	} else {
		*return_value = acpi_ut_strtoul_base10(string, flags);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_strtoul_base10
 *
 * PARAMETERS:  string                  - Null terminated input string
 *              flags                   - Conversion info
 *
 * RETURN:      64-bit converted integer
 *
 * DESCRIPTION: Performs a base 10 conversion of the input string to an
 *              integer value, either 32 or 64 bits.
 *              Note: String must be valid and non-null.
 *
 ******************************************************************************/

static u64 acpi_ut_strtoul_base10(char *string, u32 flags)
{
	int ascii_digit;
	u64 next_value;
	u64 return_value = 0;

	/* Main loop: convert each ASCII byte in the input string */

	while (*string) {
		ascii_digit = *string;
		if (!isdigit(ascii_digit)) {

			/* Not ASCII 0-9, terminate */

			goto exit;
		}

		/* Convert and insert (add) the decimal digit */

		next_value =
		    (return_value * 10) + (ascii_digit - ACPI_ASCII_ZERO);

		/* Check for overflow (32 or 64 bit) - return current converted value */

		if (((flags & ACPI_STRTOUL_32BIT) && (next_value > ACPI_UINT32_MAX)) || (next_value < return_value)) {	/* 64-bit overflow case */
			goto exit;
		}

		return_value = next_value;
		string++;
	}

exit:
	return (return_value);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_strtoul_base16
 *
 * PARAMETERS:  string                  - Null terminated input string
 *              flags                   - conversion info
 *
 * RETURN:      64-bit converted integer
 *
 * DESCRIPTION: Performs a base 16 conversion of the input string to an
 *              integer value, either 32 or 64 bits.
 *              Note: String must be valid and non-null.
 *
 ******************************************************************************/

static u64 acpi_ut_strtoul_base16(char *string, u32 flags)
{
	int ascii_digit;
	u32 valid_digits = 1;
	u64 return_value = 0;

	/* Main loop: convert each ASCII byte in the input string */

	while (*string) {

		/* Check for overflow (32 or 64 bit) - return current converted value */

		if ((valid_digits > 16) ||
		    ((valid_digits > 8) && (flags & ACPI_STRTOUL_32BIT))) {
			goto exit;
		}

		ascii_digit = *string;
		if (!isxdigit(ascii_digit)) {

			/* Not Hex ASCII A-F, a-f, or 0-9, terminate */

			goto exit;
		}

		/* Convert and insert the hex digit */

		return_value =
		    (return_value << 4) |
		    acpi_ut_ascii_char_to_hex(ascii_digit);

		string++;
		valid_digits++;
	}

exit:
	return (return_value);
}