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2660663f | 1 | /* |
0d6de953 MS |
2 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
3 | * Copyright (C) 2008-2009 PetaLogix | |
2660663f MS |
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> | |
2660663f MS |
25 | #include <linux/string.h> |
26 | ||
27 | #define VERIFY_READ 0 | |
28 | #define VERIFY_WRITE 1 | |
29 | ||
40db0834 MS |
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 | ||
357bc3c9 MS |
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 | */ | |
70 | struct exception_table_entry { | |
71 | unsigned long insn, fixup; | |
72 | }; | |
40db0834 | 73 | |
527bdb52 MS |
74 | /* Returns 0 if exception not found and fixup otherwise. */ |
75 | extern unsigned long search_exception_table(unsigned long); | |
76 | ||
0d6de953 MS |
77 | #ifndef CONFIG_MMU |
78 | ||
60a729f7 MS |
79 | /* Check against bounds of physical memory */ |
80 | static inline int ___range_ok(unsigned long addr, unsigned long size) | |
81 | { | |
82 | return ((addr < memory_start) || | |
83 | ((addr + size) > memory_end)); | |
84 | } | |
2660663f MS |
85 | |
86 | #define __range_ok(addr, size) \ | |
87 | ___range_ok((unsigned long)(addr), (unsigned long)(size)) | |
88 | ||
89 | #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) | |
40b1156d MS |
90 | |
91 | #else | |
92 | ||
93 | /* | |
94 | * Address is valid if: | |
95 | * - "addr", "addr + size" and "size" are all below the limit | |
96 | */ | |
97 | #define access_ok(type, addr, size) \ | |
98 | (get_fs().seg > (((unsigned long)(addr)) | \ | |
99 | (size) | ((unsigned long)(addr) + (size)))) | |
100 | ||
101 | /* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n", | |
102 | type?"WRITE":"READ",addr,size,get_fs().seg)) */ | |
103 | ||
104 | #endif | |
105 | ||
106 | #ifdef CONFIG_MMU | |
107 | # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" | |
108 | # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" | |
109 | #else | |
110 | # define __FIXUP_SECTION ".section .discard,\"ax\"\n" | |
111 | # define __EX_TABLE_SECTION ".section .discard,\"a\"\n" | |
112 | #endif | |
113 | ||
94804a9b MS |
114 | extern unsigned long __copy_tofrom_user(void __user *to, |
115 | const void __user *from, unsigned long size); | |
116 | ||
527bdb52 MS |
117 | /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ |
118 | static inline unsigned long __must_check __clear_user(void __user *to, | |
119 | unsigned long n) | |
120 | { | |
121 | /* normal memset with two words to __ex_table */ | |
122 | __asm__ __volatile__ ( \ | |
123 | "1: sb r0, %2, r0;" \ | |
124 | " addik %0, %0, -1;" \ | |
125 | " bneid %0, 1b;" \ | |
126 | " addik %2, %2, 1;" \ | |
127 | "2: " \ | |
128 | __EX_TABLE_SECTION \ | |
129 | ".word 1b,2b;" \ | |
130 | ".previous;" \ | |
131 | : "=r"(n) \ | |
132 | : "0"(n), "r"(to) | |
133 | ); | |
134 | return n; | |
135 | } | |
136 | ||
137 | static inline unsigned long __must_check clear_user(void __user *to, | |
138 | unsigned long n) | |
139 | { | |
140 | might_sleep(); | |
141 | if (unlikely(!access_ok(VERIFY_WRITE, to, n))) | |
142 | return n; | |
143 | ||
144 | return __clear_user(to, n); | |
145 | } | |
146 | ||
cca79120 | 147 | /* put_user and get_user macros */ |
3a6d7724 MS |
148 | extern long __user_bad(void); |
149 | ||
150 | #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ | |
151 | ({ \ | |
152 | __asm__ __volatile__ ( \ | |
153 | "1:" insn " %1, %2, r0;" \ | |
154 | " addk %0, r0, r0;" \ | |
155 | "2: " \ | |
156 | __FIXUP_SECTION \ | |
157 | "3: brid 2b;" \ | |
158 | " addik %0, r0, %3;" \ | |
159 | ".previous;" \ | |
160 | __EX_TABLE_SECTION \ | |
161 | ".word 1b,3b;" \ | |
162 | ".previous;" \ | |
163 | : "=&r"(__gu_err), "=r"(__gu_val) \ | |
164 | : "r"(__gu_ptr), "i"(-EFAULT) \ | |
165 | ); \ | |
166 | }) | |
167 | ||
168 | /** | |
169 | * get_user: - Get a simple variable from user space. | |
170 | * @x: Variable to store result. | |
171 | * @ptr: Source address, in user space. | |
172 | * | |
173 | * Context: User context only. This function may sleep. | |
174 | * | |
175 | * This macro copies a single simple variable from user space to kernel | |
176 | * space. It supports simple types like char and int, but not larger | |
177 | * data types like structures or arrays. | |
178 | * | |
179 | * @ptr must have pointer-to-simple-variable type, and the result of | |
180 | * dereferencing @ptr must be assignable to @x without a cast. | |
181 | * | |
182 | * Returns zero on success, or -EFAULT on error. | |
183 | * On error, the variable @x is set to zero. | |
184 | */ | |
838d2406 | 185 | |
3a6d7724 MS |
186 | #define __get_user(x, ptr) \ |
187 | ({ \ | |
188 | unsigned long __gu_val; \ | |
189 | /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ | |
190 | long __gu_err; \ | |
191 | switch (sizeof(*(ptr))) { \ | |
192 | case 1: \ | |
193 | __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ | |
194 | break; \ | |
195 | case 2: \ | |
196 | __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ | |
197 | break; \ | |
198 | case 4: \ | |
199 | __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ | |
200 | break; \ | |
201 | default: \ | |
202 | /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ | |
203 | } \ | |
204 | x = (__typeof__(*(ptr))) __gu_val; \ | |
205 | __gu_err; \ | |
0d6de953 | 206 | }) |
2660663f | 207 | |
3a6d7724 MS |
208 | |
209 | #define get_user(x, ptr) \ | |
210 | ({ \ | |
211 | access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \ | |
212 | ? __get_user((x), (ptr)) : -EFAULT; \ | |
213 | }) | |
214 | ||
ef4e277b MS |
215 | #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ |
216 | ({ \ | |
217 | __asm__ __volatile__ ( \ | |
218 | "1:" insn " %1, %2, r0;" \ | |
219 | " addk %0, r0, r0;" \ | |
220 | "2: " \ | |
221 | __FIXUP_SECTION \ | |
222 | "3: brid 2b;" \ | |
223 | " addik %0, r0, %3;" \ | |
224 | ".previous;" \ | |
225 | __EX_TABLE_SECTION \ | |
226 | ".word 1b,3b;" \ | |
227 | ".previous;" \ | |
228 | : "=&r"(__gu_err) \ | |
229 | : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ | |
230 | ); \ | |
231 | }) | |
2660663f | 232 | |
ef4e277b | 233 | #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ |
0d6de953 | 234 | ({ \ |
ef4e277b MS |
235 | __asm__ __volatile__ (" lwi %0, %1, 0;" \ |
236 | "1: swi %0, %2, 0;" \ | |
237 | " lwi %0, %1, 4;" \ | |
238 | "2: swi %0, %2, 4;" \ | |
239 | " addk %0, r0, r0;" \ | |
240 | "3: " \ | |
241 | __FIXUP_SECTION \ | |
242 | "4: brid 3b;" \ | |
243 | " addik %0, r0, %3;" \ | |
244 | ".previous;" \ | |
245 | __EX_TABLE_SECTION \ | |
246 | ".word 1b,4b,2b,4b;" \ | |
247 | ".previous;" \ | |
248 | : "=&r"(__gu_err) \ | |
249 | : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ | |
250 | ); \ | |
0d6de953 | 251 | }) |
2660663f | 252 | |
cca79120 MS |
253 | /** |
254 | * put_user: - Write a simple value into user space. | |
255 | * @x: Value to copy to user space. | |
256 | * @ptr: Destination address, in user space. | |
257 | * | |
258 | * Context: User context only. This function may sleep. | |
259 | * | |
260 | * This macro copies a single simple value from kernel space to user | |
261 | * space. It supports simple types like char and int, but not larger | |
262 | * data types like structures or arrays. | |
263 | * | |
264 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
265 | * to the result of dereferencing @ptr. | |
266 | * | |
267 | * Returns zero on success, or -EFAULT on error. | |
268 | */ | |
269 | ||
ef4e277b MS |
270 | #define __put_user(x, ptr) \ |
271 | ({ \ | |
272 | __typeof__(*(ptr)) volatile __gu_val = (x); \ | |
273 | long __gu_err = 0; \ | |
274 | switch (sizeof(__gu_val)) { \ | |
275 | case 1: \ | |
276 | __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ | |
277 | break; \ | |
278 | case 2: \ | |
279 | __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ | |
280 | break; \ | |
281 | case 4: \ | |
282 | __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ | |
283 | break; \ | |
284 | case 8: \ | |
285 | __put_user_asm_8((ptr), __gu_val, __gu_err); \ | |
286 | break; \ | |
287 | default: \ | |
288 | /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ | |
289 | } \ | |
290 | __gu_err; \ | |
291 | }) | |
2660663f | 292 | |
cca79120 MS |
293 | #ifndef CONFIG_MMU |
294 | ||
0d6de953 | 295 | #define put_user(x, ptr) __put_user((x), (ptr)) |
2660663f | 296 | |
0d6de953 MS |
297 | #else /* CONFIG_MMU */ |
298 | ||
8b651aa4 MS |
299 | #define put_user(x, ptr) \ |
300 | ({ \ | |
301 | access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \ | |
302 | ? __put_user((x), (ptr)) : -EFAULT; \ | |
0d6de953 | 303 | }) |
94804a9b | 304 | #endif /* CONFIG_MMU */ |
cca79120 | 305 | |
89ae9753 | 306 | /* copy_to_from_user */ |
4270690b MS |
307 | #define __copy_from_user(to, from, n) \ |
308 | __copy_tofrom_user((__force void __user *)(to), \ | |
309 | (void __user *)(from), (n)) | |
95dfbbe4 JW |
310 | #define __copy_from_user_inatomic(to, from, n) \ |
311 | copy_from_user((to), (from), (n)) | |
0d6de953 | 312 | |
4270690b MS |
313 | static inline long copy_from_user(void *to, |
314 | const void __user *from, unsigned long n) | |
315 | { | |
316 | might_sleep(); | |
317 | if (access_ok(VERIFY_READ, from, n)) | |
318 | return __copy_from_user(to, from, n); | |
89ae9753 | 319 | return n; |
4270690b MS |
320 | } |
321 | ||
cc5a428b | 322 | #define __copy_to_user(to, from, n) \ |
4270690b | 323 | __copy_tofrom_user((void __user *)(to), \ |
cc5a428b | 324 | (__force const void __user *)(from), (n)) |
0d6de953 MS |
325 | #define __copy_to_user_inatomic(to, from, n) copy_to_user((to), (from), (n)) |
326 | ||
cc5a428b MS |
327 | static inline long copy_to_user(void __user *to, |
328 | const void *from, unsigned long n) | |
329 | { | |
330 | might_sleep(); | |
331 | if (access_ok(VERIFY_WRITE, to, n)) | |
332 | return __copy_to_user(to, from, n); | |
89ae9753 MS |
333 | return n; |
334 | } | |
335 | ||
336 | /* | |
337 | * Copy a null terminated string from userspace. | |
338 | */ | |
339 | extern int __strncpy_user(char *to, const char __user *from, int len); | |
340 | ||
341 | #define __strncpy_from_user __strncpy_user | |
342 | ||
343 | static inline long | |
344 | strncpy_from_user(char *dst, const char __user *src, long count) | |
345 | { | |
346 | if (!access_ok(VERIFY_READ, src, 1)) | |
347 | return -EFAULT; | |
348 | return __strncpy_from_user(dst, src, count); | |
349 | } | |
350 | ||
351 | /* | |
352 | * Return the size of a string (including the ending 0) | |
353 | * | |
354 | * Return 0 on exception, a value greater than N if too long | |
355 | */ | |
356 | extern int __strnlen_user(const char __user *sstr, int len); | |
357 | ||
358 | static inline long strnlen_user(const char __user *src, long n) | |
359 | { | |
360 | if (!access_ok(VERIFY_READ, src, 1)) | |
361 | return 0; | |
362 | return __strnlen_user(src, n); | |
cc5a428b MS |
363 | } |
364 | ||
2660663f MS |
365 | #endif /* __ASSEMBLY__ */ |
366 | #endif /* __KERNEL__ */ | |
367 | ||
368 | #endif /* _ASM_MICROBLAZE_UACCESS_H */ |