aboutsummaryrefslogtreecommitdiffstats
path: root/arch/csky/include/asm/uaccess.h
blob: eaa1c3403a42458bec78a0a1cbf9678ec7a45b84 (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
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.

#ifndef __ASM_CSKY_UACCESS_H
#define __ASM_CSKY_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/version.h>
#include <asm/segment.h>

static inline int access_ok(const void *addr, unsigned long size)
{
	unsigned long limit = current_thread_info()->addr_limit.seg;

	return (((unsigned long)addr < limit) &&
		((unsigned long)(addr + size) < limit));
}

#define __addr_ok(addr) (access_ok(addr, 0))

extern int __put_user_bad(void);

/*
 * Tell gcc we read from memory instead of writing: this is because
 * we do not write to any memory gcc knows about, so there are no
 * aliasing issues.
 */

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the ugliness from the user.
 *
 * The "__xxx" versions of the user access functions are versions that
 * do not verify the address space, that must have been done previously
 * with a separate "access_ok()" call (this is used when we do multiple
 * accesses to the same area of user memory).
 *
 * As we use the same address space for kernel and user data on
 * Ckcore, we can just do these as direct assignments.  (Of course, the
 * exception handling means that it's no longer "just"...)
 */

#define put_user(x, ptr) \
	__put_user_check((x), (ptr), sizeof(*(ptr)))

#define __put_user(x, ptr) \
	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))

#define __ptr(x) ((unsigned long *)(x))

#define get_user(x, ptr) \
	__get_user_check((x), (ptr), sizeof(*(ptr)))

#define __get_user(x, ptr) \
	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))

#define __put_user_nocheck(x, ptr, size)				\
({									\
	long __pu_err = 0;						\
	typeof(*(ptr)) *__pu_addr = (ptr);				\
	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
	if (__pu_addr)							\
		__put_user_size(__pu_val, (__pu_addr), (size),		\
				__pu_err);				\
	__pu_err;							\
})

#define __put_user_check(x, ptr, size)					\
({									\
	long __pu_err = -EFAULT;					\
	typeof(*(ptr)) *__pu_addr = (ptr);				\
	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
	if (access_ok(__pu_addr, size) && __pu_addr)	\
		__put_user_size(__pu_val, __pu_addr, (size), __pu_err);	\
	__pu_err;							\
})

#define __put_user_size(x, ptr, size, retval)		\
do {							\
	retval = 0;					\
	switch (size) {                                 \
	case 1:						\
		__put_user_asm_b(x, ptr, retval);	\
		break;					\
	case 2:						\
		__put_user_asm_h(x, ptr, retval);	\
		break;					\
	case 4:						\
		__put_user_asm_w(x, ptr, retval);	\
		break;					\
	case 8:						\
		__put_user_asm_64(x, ptr, retval);	\
		break;					\
	default:					\
		__put_user_bad();			\
	}	                                        \
} while (0)

/*
 * We don't tell gcc that we are accessing memory, but this is OK
 * because we do not write to any memory gcc knows about, so there
 * are no aliasing issues.
 *
 * Note that PC at a fault is the address *after* the faulting
 * instruction.
 */
#define __put_user_asm_b(x, ptr, err)			\
do {							\
	int errcode;					\
	asm volatile(					\
	"1:     stb   %1, (%2,0)	\n"		\
	"       br    3f		\n"		\
	"2:     mov   %0, %3		\n"		\
	"       br    3f		\n"		\
	".section __ex_table, \"a\"	\n"		\
	".align   2			\n"		\
	".long    1b,2b			\n"		\
	".previous			\n"		\
	"3:				\n"		\
	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
	: "memory");					\
} while (0)

#define __put_user_asm_h(x, ptr, err)			\
do {							\
	int errcode;					\
	asm volatile(					\
	"1:     sth   %1, (%2,0)	\n"		\
	"       br    3f		\n"		\
	"2:     mov   %0, %3		\n"		\
	"       br    3f		\n"		\
	".section __ex_table, \"a\"	\n"		\
	".align   2			\n"		\
	".long    1b,2b			\n"		\
	".previous			\n"		\
	"3:				\n"		\
	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
	: "memory");					\
} while (0)

#define __put_user_asm_w(x, ptr, err)			\
do {							\
	int errcode;					\
	asm volatile(					\
	"1:     stw   %1, (%2,0)	\n"		\
	"       br    3f		\n"		\
	"2:     mov   %0, %3		\n"		\
	"       br    3f		\n"		\
	".section __ex_table,\"a\"	\n"		\
	".align   2			\n"		\
	".long    1b, 2b		\n"		\
	".previous			\n"		\
	"3:				\n"		\
	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
	: "memory");					\
} while (0)

#define __put_user_asm_64(x, ptr, err)				\
do {								\
	int tmp;						\
	int errcode;						\
	typeof(*(ptr))src = (typeof(*(ptr)))x;			\
	typeof(*(ptr))*psrc = &src;				\
								\
	asm volatile(						\
	"     ldw     %3, (%1, 0)     \n"			\
	"1:   stw     %3, (%2, 0)     \n"			\
	"     ldw     %3, (%1, 4)     \n"			\
	"2:   stw     %3, (%2, 4)     \n"			\
	"     br      4f              \n"			\
	"3:   mov     %0, %4          \n"			\
	"     br      4f              \n"			\
	".section __ex_table, \"a\"   \n"			\
	".align   2                   \n"			\
	".long    1b, 3b              \n"			\
	".long    2b, 3b              \n"			\
	".previous                    \n"			\
	"4:                           \n"			\
	: "=r"(err), "=r"(psrc), "=r"(ptr),			\
	  "=r"(tmp), "=r"(errcode)				\
	: "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT)	\
	: "memory");						\
} while (0)

#define __get_user_nocheck(x, ptr, size)			\
({								\
	long  __gu_err;						\
	__get_user_size(x, (ptr), (size), __gu_err);		\
	__gu_err;						\
})

#define __get_user_check(x, ptr, size)				\
({								\
	int __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);	\
	if (access_ok(__gu_ptr, size) && __gu_ptr)	\
		__get_user_size(x, __gu_ptr, size, __gu_err);	\
	__gu_err;						\
})

#define __get_user_size(x, ptr, size, retval)			\
do {								\
	switch (size) {						\
	case 1:							\
		__get_user_asm_common((x), ptr, "ldb", retval);	\
		break;						\
	case 2:							\
		__get_user_asm_common((x), ptr, "ldh", retval);	\
		break;						\
	case 4:							\
		__get_user_asm_common((x), ptr, "ldw", retval);	\
		break;						\
	default:						\
		x = 0;						\
		(retval) = __get_user_bad();			\
	}							\
} while (0)

#define __get_user_asm_common(x, ptr, ins, err)			\
do {								\
	int errcode;						\
	asm volatile(						\
	"1:   " ins " %1, (%4,0)	\n"			\
	"       br    3f		\n"			\
	/* Fix up codes */					\
	"2:     mov   %0, %2		\n"			\
	"       movi  %1, 0		\n"			\
	"       br    3f		\n"			\
	".section __ex_table,\"a\"      \n"			\
	".align   2			\n"			\
	".long    1b, 2b		\n"			\
	".previous			\n"			\
	"3:				\n" 			\
	: "=r"(err), "=r"(x), "=r"(errcode)			\
	: "0"(0), "r"(ptr), "2"(-EFAULT)			\
	: "memory");						\
} while (0)

extern int __get_user_bad(void);

#define __copy_user(to, from, n)			\
do {							\
	int w0, w1, w2, w3;				\
	asm volatile(					\
	"0:     cmpnei  %1, 0           \n"		\
	"       bf      8f              \n"		\
	"       mov     %3, %1          \n"		\
	"       or      %3, %2          \n"		\
	"       andi    %3, 3           \n"		\
	"       cmpnei  %3, 0           \n"		\
	"       bf      1f              \n"		\
	"       br      5f              \n"		\
	"1:     cmplti  %0, 16          \n" /* 4W */	\
	"       bt      3f              \n"		\
	"       ldw     %3, (%2, 0)     \n"		\
	"       ldw     %4, (%2, 4)     \n"		\
	"       ldw     %5, (%2, 8)     \n"		\
	"       ldw     %6, (%2, 12)    \n"		\
	"2:     stw     %3, (%1, 0)     \n"		\
	"9:     stw     %4, (%1, 4)     \n"		\
	"10:    stw     %5, (%1, 8)     \n"		\
	"11:    stw     %6, (%1, 12)    \n"		\
	"       addi    %2, 16          \n"		\
	"       addi    %1, 16          \n"		\
	"       subi    %0, 16          \n"		\
	"       br      1b              \n"		\
	"3:     cmplti  %0, 4           \n" /* 1W */	\
	"       bt      5f              \n"		\
	"       ldw     %3, (%2, 0)     \n"		\
	"4:     stw     %3, (%1, 0)     \n"		\
	"       addi    %2, 4           \n"		\
	"       addi    %1, 4           \n"		\
	"       subi    %0, 4           \n"		\
	"       br      3b              \n"		\
	"5:     cmpnei  %0, 0           \n"  /* 1B */   \
	"       bf      8f              \n"		\
	"       ldb     %3, (%2, 0)     \n"		\
	"6:     stb     %3, (%1, 0)     \n"		\
	"       addi    %2,  1          \n"		\
	"       addi    %1,  1          \n"		\
	"       subi    %0,  1          \n"		\
	"       br      5b              \n"		\
	"7:     br      8f              \n"		\
	".section __ex_table, \"a\"     \n"		\
	".align   2                     \n"		\
	".long    2b, 7b                \n"		\
	".long    9b, 7b                \n"		\
	".long   10b, 7b                \n"		\
	".long   11b, 7b                \n"		\
	".long    4b, 7b                \n"		\
	".long    6b, 7b                \n"		\
	".previous                      \n"		\
	"8:                             \n"		\
	: "=r"(n), "=r"(to), "=r"(from), "=r"(w0),	\
	  "=r"(w1), "=r"(w2), "=r"(w3)			\
	: "0"(n), "1"(to), "2"(from)			\
	: "memory");					\
} while (0)

#define __copy_user_zeroing(to, from, n)		\
do {							\
	int tmp;					\
	int nsave;					\
	asm volatile(					\
	"0:     cmpnei  %1, 0           \n"		\
	"       bf      7f              \n"		\
	"       mov     %3, %1          \n"		\
	"       or      %3, %2          \n"		\
	"       andi    %3, 3           \n"		\
	"       cmpnei  %3, 0           \n"		\
	"       bf      1f              \n"		\
	"       br      5f              \n"		\
	"1:     cmplti  %0, 16          \n"		\
	"       bt      3f              \n"		\
	"2:     ldw     %3, (%2, 0)     \n"		\
	"10:    ldw     %4, (%2, 4)     \n"		\
	"       stw     %3, (%1, 0)     \n"		\
	"       stw     %4, (%1, 4)     \n"		\
	"11:    ldw     %3, (%2, 8)     \n"		\
	"12:    ldw     %4, (%2, 12)    \n"		\
	"       stw     %3, (%1, 8)     \n"		\
	"       stw     %4, (%1, 12)    \n"		\
	"       addi    %2, 16          \n"		\
	"       addi    %1, 16          \n"		\
	"       subi    %0, 16          \n"		\
	"       br      1b              \n"		\
	"3:     cmplti  %0, 4           \n"		\
	"       bt      5f              \n"		\
	"4:     ldw     %3, (%2, 0)     \n"		\
	"       stw     %3, (%1, 0)     \n"		\
	"       addi    %2, 4           \n"		\
	"       addi    %1, 4           \n"		\
	"       subi    %0, 4           \n"		\
	"       br      3b              \n"		\
	"5:     cmpnei  %0, 0           \n"		\
	"       bf      7f              \n"		\
	"6:     ldb     %3, (%2, 0)     \n"		\
	"       stb     %3, (%1, 0)     \n"		\
	"       addi    %2,  1          \n"		\
	"       addi    %1,  1          \n"		\
	"       subi    %0,  1          \n"		\
	"       br      5b              \n"		\
	"8:     mov     %3, %0          \n"		\
	"       movi    %4, 0           \n"		\
	"9:     stb     %4, (%1, 0)     \n"		\
	"       addi    %1, 1           \n"		\
	"       subi    %3, 1           \n"		\
	"       cmpnei  %3, 0           \n"		\
	"       bt      9b              \n"		\
	"       br      7f              \n"		\
	".section __ex_table, \"a\"     \n"		\
	".align   2                     \n"		\
	".long    2b, 8b                \n"		\
	".long   10b, 8b                \n"		\
	".long   11b, 8b                \n"		\
	".long   12b, 8b                \n"		\
	".long    4b, 8b                \n"		\
	".long    6b, 8b                \n"		\
	".previous                      \n"		\
	"7:                             \n"		\
	: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),	\
	  "=r"(tmp)					\
	: "0"(n), "1"(to), "2"(from)			\
	: "memory");					\
} while (0)

unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);

unsigned long clear_user(void *to, unsigned long n);
unsigned long __clear_user(void __user *to, unsigned long n);

long strncpy_from_user(char *dst, const char *src, long count);
long __strncpy_from_user(char *dst, const char *src, long count);

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 on exception, a value greater than N if too long
 */
long strnlen_user(const char *src, long n);

#define strlen_user(str) strnlen_user(str, 32767)

struct exception_table_entry {
	unsigned long insn;
	unsigned long nextinsn;
};

extern int fixup_exception(struct pt_regs *regs);

#endif /* __ASM_CSKY_UACCESS_H */