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microblaze: move noMMU __range_ok function to uaccess.h
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2660663f 1/*
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2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2008-2009 PetaLogix
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4 * Copyright (C) 2006 Atmark Techno, Inc.
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10
11#ifndef _ASM_MICROBLAZE_UACCESS_H
12#define _ASM_MICROBLAZE_UACCESS_H
13
14#ifdef __KERNEL__
15#ifndef __ASSEMBLY__
16
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/sched.h> /* RLIMIT_FSIZE */
20#include <linux/mm.h>
21
22#include <asm/mmu.h>
23#include <asm/page.h>
24#include <asm/pgtable.h>
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25#include <linux/string.h>
26
27#define VERIFY_READ 0
28#define VERIFY_WRITE 1
29
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30/*
31 * On Microblaze the fs value is actually the top of the corresponding
32 * address space.
33 *
34 * The fs value determines whether argument validity checking should be
35 * performed or not. If get_fs() == USER_DS, checking is performed, with
36 * get_fs() == KERNEL_DS, checking is bypassed.
37 *
38 * For historical reasons, these macros are grossly misnamed.
39 *
40 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
41 */
42# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
43
44# ifndef CONFIG_MMU
45# define KERNEL_DS MAKE_MM_SEG(0)
46# define USER_DS KERNEL_DS
47# else
48# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
49# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
50# endif
51
52# define get_ds() (KERNEL_DS)
53# define get_fs() (current_thread_info()->addr_limit)
54# define set_fs(val) (current_thread_info()->addr_limit = (val))
55
56# define segment_eq(a, b) ((a).seg == (b).seg)
57
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58/*
59 * The exception table consists of pairs of addresses: the first is the
60 * address of an instruction that is allowed to fault, and the second is
61 * the address at which the program should continue. No registers are
62 * modified, so it is entirely up to the continuation code to figure out
63 * what to do.
64 *
65 * All the routines below use bits of fixup code that are out of line
66 * with the main instruction path. This means when everything is well,
67 * we don't even have to jump over them. Further, they do not intrude
68 * on our cache or tlb entries.
69 */
70struct exception_table_entry {
71 unsigned long insn, fixup;
72};
40db0834 73
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74#define __clear_user(addr, n) (memset((void *)(addr), 0, (n)), 0)
75
76#ifndef CONFIG_MMU
77
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78/* Check against bounds of physical memory */
79static inline int ___range_ok(unsigned long addr, unsigned long size)
80{
81 return ((addr < memory_start) ||
82 ((addr + size) > memory_end));
83}
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84
85#define __range_ok(addr, size) \
86 ___range_ok((unsigned long)(addr), (unsigned long)(size))
87
88#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
89#define __access_ok(add, size) (__range_ok((addr), (size)) == 0)
90
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91/* Undefined function to trigger linker error */
92extern int bad_user_access_length(void);
93
2660663f 94/* FIXME this is function for optimalization -> memcpy */
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95#define __get_user(var, ptr) \
96({ \
97 int __gu_err = 0; \
98 switch (sizeof(*(ptr))) { \
99 case 1: \
100 case 2: \
101 case 4: \
102 (var) = *(ptr); \
103 break; \
104 case 8: \
105 memcpy((void *) &(var), (ptr), 8); \
106 break; \
107 default: \
108 (var) = 0; \
109 __gu_err = __get_user_bad(); \
110 break; \
111 } \
112 __gu_err; \
113})
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114
115#define __get_user_bad() (bad_user_access_length(), (-EFAULT))
116
0d6de953 117/* FIXME is not there defined __pu_val */
2660663f 118#define __put_user(var, ptr) \
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119({ \
120 int __pu_err = 0; \
121 switch (sizeof(*(ptr))) { \
122 case 1: \
123 case 2: \
124 case 4: \
125 *(ptr) = (var); \
126 break; \
127 case 8: { \
128 typeof(*(ptr)) __pu_val = (var); \
129 memcpy(ptr, &__pu_val, sizeof(__pu_val)); \
130 } \
131 break; \
132 default: \
133 __pu_err = __put_user_bad(); \
134 break; \
135 } \
136 __pu_err; \
137})
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138
139#define __put_user_bad() (bad_user_access_length(), (-EFAULT))
140
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141#define put_user(x, ptr) __put_user((x), (ptr))
142#define get_user(x, ptr) __get_user((x), (ptr))
2660663f 143
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144#define copy_to_user(to, from, n) (memcpy((to), (from), (n)), 0)
145#define copy_from_user(to, from, n) (memcpy((to), (from), (n)), 0)
2660663f 146
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147#define __copy_to_user(to, from, n) (copy_to_user((to), (from), (n)))
148#define __copy_from_user(to, from, n) (copy_from_user((to), (from), (n)))
149#define __copy_to_user_inatomic(to, from, n) \
150 (__copy_to_user((to), (from), (n)))
151#define __copy_from_user_inatomic(to, from, n) \
152 (__copy_from_user((to), (from), (n)))
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153
154static inline unsigned long clear_user(void *addr, unsigned long size)
155{
156 if (access_ok(VERIFY_WRITE, addr, size))
157 size = __clear_user(addr, size);
158 return size;
159}
160
0d6de953 161/* Returns 0 if exception not found and fixup otherwise. */
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162extern unsigned long search_exception_table(unsigned long);
163
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164extern long strncpy_from_user(char *dst, const char *src, long count);
165extern long strnlen_user(const char *src, long count);
166
167#else /* CONFIG_MMU */
168
169/*
170 * Address is valid if:
171 * - "addr", "addr + size" and "size" are all below the limit
172 */
173#define access_ok(type, addr, size) \
174 (get_fs().seg > (((unsigned long)(addr)) | \
175 (size) | ((unsigned long)(addr) + (size))))
176
177/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
178 type?"WRITE":"READ",addr,size,get_fs().seg)) */
179
180/*
181 * All the __XXX versions macros/functions below do not perform
182 * access checking. It is assumed that the necessary checks have been
183 * already performed before the finction (macro) is called.
184 */
185
186#define get_user(x, ptr) \
187({ \
188 access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
189 ? __get_user((x), (ptr)) : -EFAULT; \
190})
191
192#define put_user(x, ptr) \
193({ \
194 access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \
195 ? __put_user((x), (ptr)) : -EFAULT; \
196})
197
198#define __get_user(x, ptr) \
199({ \
200 unsigned long __gu_val; \
201 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \
202 long __gu_err; \
203 switch (sizeof(*(ptr))) { \
204 case 1: \
205 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \
206 break; \
207 case 2: \
208 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \
209 break; \
210 case 4: \
211 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \
212 break; \
213 default: \
214 __gu_val = 0; __gu_err = -EINVAL; \
215 } \
216 x = (__typeof__(*(ptr))) __gu_val; \
217 __gu_err; \
218})
219
220#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
221({ \
222 __asm__ __volatile__ ( \
223 "1:" insn " %1, %2, r0; \
224 addk %0, r0, r0; \
225 2: \
226 .section .fixup,\"ax\"; \
227 3: brid 2b; \
228 addik %0, r0, %3; \
229 .previous; \
230 .section __ex_table,\"a\"; \
231 .word 1b,3b; \
232 .previous;" \
233 : "=r"(__gu_err), "=r"(__gu_val) \
234 : "r"(__gu_ptr), "i"(-EFAULT) \
235 ); \
236})
237
238#define __put_user(x, ptr) \
239({ \
7bcb63b2 240 __typeof__(*(ptr)) volatile __gu_val = (x); \
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241 long __gu_err = 0; \
242 switch (sizeof(__gu_val)) { \
243 case 1: \
244 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \
245 break; \
246 case 2: \
247 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \
248 break; \
249 case 4: \
250 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \
251 break; \
252 case 8: \
253 __put_user_asm_8((ptr), __gu_val, __gu_err); \
254 break; \
255 default: \
256 __gu_err = -EINVAL; \
257 } \
258 __gu_err; \
259})
260
261#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \
262({ \
263__asm__ __volatile__ (" lwi %0, %1, 0; \
264 1: swi %0, %2, 0; \
265 lwi %0, %1, 4; \
266 2: swi %0, %2, 4; \
267 addk %0,r0,r0; \
268 3: \
269 .section .fixup,\"ax\"; \
270 4: brid 3b; \
271 addik %0, r0, %3; \
272 .previous; \
273 .section __ex_table,\"a\"; \
274 .word 1b,4b,2b,4b; \
275 .previous;" \
276 : "=&r"(__gu_err) \
277 : "r"(&__gu_val), \
278 "r"(__gu_ptr), "i"(-EFAULT) \
279 ); \
280})
281
282#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
283({ \
284 __asm__ __volatile__ ( \
285 "1:" insn " %1, %2, r0; \
286 addk %0, r0, r0; \
287 2: \
288 .section .fixup,\"ax\"; \
289 3: brid 2b; \
290 addik %0, r0, %3; \
291 .previous; \
292 .section __ex_table,\"a\"; \
293 .word 1b,3b; \
294 .previous;" \
295 : "=r"(__gu_err) \
296 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
297 ); \
298})
299
300/*
301 * Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail.
302 */
303static inline int clear_user(char *to, int size)
304{
305 if (size && access_ok(VERIFY_WRITE, to, size)) {
306 __asm__ __volatile__ (" \
307 1: \
308 sb r0, %2, r0; \
309 addik %0, %0, -1; \
310 bneid %0, 1b; \
311 addik %2, %2, 1; \
312 2: \
313 .section __ex_table,\"a\"; \
314 .word 1b,2b; \
315 .section .text;" \
316 : "=r"(size) \
317 : "0"(size), "r"(to)
318 );
319 }
320 return size;
321}
322
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323#define __copy_from_user(to, from, n) copy_from_user((to), (from), (n))
324#define __copy_from_user_inatomic(to, from, n) \
325 copy_from_user((to), (from), (n))
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326
327#define copy_to_user(to, from, n) \
328 (access_ok(VERIFY_WRITE, (to), (n)) ? \
329 __copy_tofrom_user((void __user *)(to), \
330 (__force const void __user *)(from), (n)) \
331 : -EFAULT)
332
333#define __copy_to_user(to, from, n) copy_to_user((to), (from), (n))
334#define __copy_to_user_inatomic(to, from, n) copy_to_user((to), (from), (n))
335
336#define copy_from_user(to, from, n) \
337 (access_ok(VERIFY_READ, (from), (n)) ? \
338 __copy_tofrom_user((__force void __user *)(to), \
339 (void __user *)(from), (n)) \
340 : -EFAULT)
341
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342extern int __strncpy_user(char *to, const char __user *from, int len);
343extern int __strnlen_user(const char __user *sstr, int len);
344
345#define strncpy_from_user(to, from, len) \
346 (access_ok(VERIFY_READ, from, 1) ? \
347 __strncpy_user(to, from, len) : -EFAULT)
348#define strnlen_user(str, len) \
349 (access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)
2660663f 350
0d6de953 351#endif /* CONFIG_MMU */
2660663f 352
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353extern unsigned long __copy_tofrom_user(void __user *to,
354 const void __user *from, unsigned long size);
355
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356#endif /* __ASSEMBLY__ */
357#endif /* __KERNEL__ */
358
359#endif /* _ASM_MICROBLAZE_UACCESS_H */