1 /*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 */
14
15 #ifndef _ASM_TILE_UACCESS_H
16 #define _ASM_TILE_UACCESS_H
17
18 /*
19 * User space memory access functions
20 */
21 #include <linux/mm.h>
22 #include <asm/processor.h>
23 #include <asm/page.h>
24
25 /*
26 * The fs value determines whether argument validity checking should be
27 * performed or not. If get_fs() == USER_DS, checking is performed, with
28 * get_fs() == KERNEL_DS, checking is bypassed.
29 *
30 * For historical reasons, these macros are grossly misnamed.
31 */
32 #define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
33
34 #define KERNEL_DS MAKE_MM_SEG(-1UL)
35 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
36
37 #define get_ds() (KERNEL_DS)
38 #define get_fs() (current_thread_info()->addr_limit)
39 #define set_fs(x) (current_thread_info()->addr_limit = (x))
40
41 #define segment_eq(a, b) ((a).seg == (b).seg)
42
43 #ifndef __tilegx__
44 /*
45 * We could allow mapping all 16 MB at 0xfc000000, but we set up a
46 * special hack in arch_setup_additional_pages() to auto-create a mapping
47 * for the first 16 KB, and it would seem strange to have different
48 * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
49 */
is_arch_mappable_range(unsigned long addr,unsigned long size)50 static inline int is_arch_mappable_range(unsigned long addr,
51 unsigned long size)
52 {
53 return (addr >= MEM_USER_INTRPT &&
54 addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
55 size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
56 }
57 #define is_arch_mappable_range is_arch_mappable_range
58 #else
59 #define is_arch_mappable_range(addr, size) 0
60 #endif
61
62 /*
63 * Note that using this definition ignores is_arch_mappable_range(),
64 * so on tilepro code that uses user_addr_max() is constrained not
65 * to reference the tilepro user-interrupt region.
66 */
67 #define user_addr_max() (current_thread_info()->addr_limit.seg)
68
69 /*
70 * Test whether a block of memory is a valid user space address.
71 * Returns 0 if the range is valid, nonzero otherwise.
72 */
73 int __range_ok(unsigned long addr, unsigned long size);
74
75 /**
76 * access_ok: - Checks if a user space pointer is valid
77 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
78 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
79 * to write to a block, it is always safe to read from it.
80 * @addr: User space pointer to start of block to check
81 * @size: Size of block to check
82 *
83 * Context: User context only. This function may sleep if pagefaults are
84 * enabled.
85 *
86 * Checks if a pointer to a block of memory in user space is valid.
87 *
88 * Returns true (nonzero) if the memory block may be valid, false (zero)
89 * if it is definitely invalid.
90 *
91 * Note that, depending on architecture, this function probably just
92 * checks that the pointer is in the user space range - after calling
93 * this function, memory access functions may still return -EFAULT.
94 */
95 #define access_ok(type, addr, size) ({ \
96 __chk_user_ptr(addr); \
97 likely(__range_ok((unsigned long)(addr), (size)) == 0); \
98 })
99
100 #include <asm/extable.h>
101
102 /*
103 * This is a type: either unsigned long, if the argument fits into
104 * that type, or otherwise unsigned long long.
105 */
106 #define __inttype(x) \
107 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
108
109 /*
110 * Support macros for __get_user().
111 * Note that __get_user() and __put_user() assume proper alignment.
112 */
113
114 #ifdef __LP64__
115 #define _ASM_PTR ".quad"
116 #define _ASM_ALIGN ".align 8"
117 #else
118 #define _ASM_PTR ".long"
119 #define _ASM_ALIGN ".align 4"
120 #endif
121
122 #define __get_user_asm(OP, x, ptr, ret) \
123 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
124 ".pushsection .fixup,\"ax\"\n" \
125 "0: { movei %1, 0; movei %0, %3 }\n" \
126 "j 9f\n" \
127 ".section __ex_table,\"a\"\n" \
128 _ASM_ALIGN "\n" \
129 _ASM_PTR " 1b, 0b\n" \
130 ".popsection\n" \
131 "9:" \
132 : "=r" (ret), "=r" (x) \
133 : "r" (ptr), "i" (-EFAULT))
134
135 #ifdef __tilegx__
136 #define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
137 #define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
138 #define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
139 #define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
140 #else
141 #define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
142 #define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
143 #define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
144 #ifdef __LITTLE_ENDIAN
145 #define __lo32(a, b) a
146 #define __hi32(a, b) b
147 #else
148 #define __lo32(a, b) b
149 #define __hi32(a, b) a
150 #endif
151 #define __get_user_8(x, ptr, ret) \
152 ({ \
153 unsigned int __a, __b; \
154 asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \
155 "2: { lw %2, %2; movei %0, 0 }\n" \
156 ".pushsection .fixup,\"ax\"\n" \
157 "0: { movei %1, 0; movei %2, 0 }\n" \
158 "{ movei %0, %4; j 9f }\n" \
159 ".section __ex_table,\"a\"\n" \
160 ".align 4\n" \
161 ".word 1b, 0b\n" \
162 ".word 2b, 0b\n" \
163 ".popsection\n" \
164 "9:" \
165 : "=r" (ret), "=r" (__a), "=&r" (__b) \
166 : "r" (ptr), "i" (-EFAULT)); \
167 (x) = (__force __typeof(x))(__inttype(x)) \
168 (((u64)__hi32(__a, __b) << 32) | \
169 __lo32(__a, __b)); \
170 })
171 #endif
172
173 extern int __get_user_bad(void)
174 __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
175
176 /**
177 * __get_user: - Get a simple variable from user space, with less checking.
178 * @x: Variable to store result.
179 * @ptr: Source address, in user space.
180 *
181 * Context: User context only. This function may sleep if pagefaults are
182 * enabled.
183 *
184 * This macro copies a single simple variable from user space to kernel
185 * space. It supports simple types like char and int, but not larger
186 * data types like structures or arrays.
187 *
188 * @ptr must have pointer-to-simple-variable type, and the result of
189 * dereferencing @ptr must be assignable to @x without a cast.
190 *
191 * Returns zero on success, or -EFAULT on error.
192 * On error, the variable @x is set to zero.
193 *
194 * Caller must check the pointer with access_ok() before calling this
195 * function.
196 */
197 #define __get_user(x, ptr) \
198 ({ \
199 int __ret; \
200 typeof(x) _x; \
201 __chk_user_ptr(ptr); \
202 switch (sizeof(*(ptr))) { \
203 case 1: __get_user_1(_x, ptr, __ret); break; \
204 case 2: __get_user_2(_x, ptr, __ret); break; \
205 case 4: __get_user_4(_x, ptr, __ret); break; \
206 case 8: __get_user_8(_x, ptr, __ret); break; \
207 default: __ret = __get_user_bad(); break; \
208 } \
209 (x) = (typeof(*(ptr))) _x; \
210 __ret; \
211 })
212
213 /* Support macros for __put_user(). */
214
215 #define __put_user_asm(OP, x, ptr, ret) \
216 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
217 ".pushsection .fixup,\"ax\"\n" \
218 "0: { movei %0, %3; j 9f }\n" \
219 ".section __ex_table,\"a\"\n" \
220 _ASM_ALIGN "\n" \
221 _ASM_PTR " 1b, 0b\n" \
222 ".popsection\n" \
223 "9:" \
224 : "=r" (ret) \
225 : "r" (ptr), "r" (x), "i" (-EFAULT))
226
227 #ifdef __tilegx__
228 #define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
229 #define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
230 #define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
231 #define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
232 #else
233 #define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
234 #define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
235 #define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
236 #define __put_user_8(x, ptr, ret) \
237 ({ \
238 u64 __x = (__force __inttype(x))(x); \
239 int __lo = (int) __x, __hi = (int) (__x >> 32); \
240 asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \
241 "2: { sw %0, %3; movei %0, 0 }\n" \
242 ".pushsection .fixup,\"ax\"\n" \
243 "0: { movei %0, %4; j 9f }\n" \
244 ".section __ex_table,\"a\"\n" \
245 ".align 4\n" \
246 ".word 1b, 0b\n" \
247 ".word 2b, 0b\n" \
248 ".popsection\n" \
249 "9:" \
250 : "=&r" (ret) \
251 : "r" (ptr), "r" (__lo32(__lo, __hi)), \
252 "r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \
253 })
254 #endif
255
256 extern int __put_user_bad(void)
257 __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
258
259 /**
260 * __put_user: - Write a simple value into user space, with less checking.
261 * @x: Value to copy to user space.
262 * @ptr: Destination address, in user space.
263 *
264 * Context: User context only. This function may sleep if pagefaults are
265 * enabled.
266 *
267 * This macro copies a single simple value from kernel space to user
268 * space. It supports simple types like char and int, but not larger
269 * data types like structures or arrays.
270 *
271 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
272 * to the result of dereferencing @ptr.
273 *
274 * Caller must check the pointer with access_ok() before calling this
275 * function.
276 *
277 * Returns zero on success, or -EFAULT on error.
278 */
279 #define __put_user(x, ptr) \
280 ({ \
281 int __ret; \
282 typeof(*(ptr)) _x = (x); \
283 __chk_user_ptr(ptr); \
284 switch (sizeof(*(ptr))) { \
285 case 1: __put_user_1(_x, ptr, __ret); break; \
286 case 2: __put_user_2(_x, ptr, __ret); break; \
287 case 4: __put_user_4(_x, ptr, __ret); break; \
288 case 8: __put_user_8(_x, ptr, __ret); break; \
289 default: __ret = __put_user_bad(); break; \
290 } \
291 __ret; \
292 })
293
294 /*
295 * The versions of get_user and put_user without initial underscores
296 * check the address of their arguments to make sure they are not
297 * in kernel space.
298 */
299 #define put_user(x, ptr) \
300 ({ \
301 __typeof__(*(ptr)) __user *__Pu_addr = (ptr); \
302 access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ? \
303 __put_user((x), (__Pu_addr)) : \
304 -EFAULT; \
305 })
306
307 #define get_user(x, ptr) \
308 ({ \
309 __typeof__(*(ptr)) const __user *__Gu_addr = (ptr); \
310 access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ? \
311 __get_user((x), (__Gu_addr)) : \
312 ((x) = 0, -EFAULT); \
313 })
314
315 extern unsigned long __must_check
316 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
317 extern unsigned long __must_check
318 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
319 #define INLINE_COPY_FROM_USER
320 #define INLINE_COPY_TO_USER
321
322 #ifdef __tilegx__
323 extern unsigned long raw_copy_in_user(
324 void __user *to, const void __user *from, unsigned long n);
325 #endif
326
327
328 extern long strnlen_user(const char __user *str, long n);
329 extern long strncpy_from_user(char *dst, const char __user *src, long);
330
331 /**
332 * clear_user: - Zero a block of memory in user space.
333 * @mem: Destination address, in user space.
334 * @len: Number of bytes to zero.
335 *
336 * Zero a block of memory in user space.
337 *
338 * Returns number of bytes that could not be cleared.
339 * On success, this will be zero.
340 */
341 extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
__clear_user(void __user * mem,unsigned long len)342 static inline unsigned long __must_check __clear_user(
343 void __user *mem, unsigned long len)
344 {
345 might_fault();
346 return clear_user_asm(mem, len);
347 }
clear_user(void __user * mem,unsigned long len)348 static inline unsigned long __must_check clear_user(
349 void __user *mem, unsigned long len)
350 {
351 if (access_ok(VERIFY_WRITE, mem, len))
352 return __clear_user(mem, len);
353 return len;
354 }
355
356 /**
357 * flush_user: - Flush a block of memory in user space from cache.
358 * @mem: Destination address, in user space.
359 * @len: Number of bytes to flush.
360 *
361 * Returns number of bytes that could not be flushed.
362 * On success, this will be zero.
363 */
364 extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
__flush_user(void __user * mem,unsigned long len)365 static inline unsigned long __must_check __flush_user(
366 void __user *mem, unsigned long len)
367 {
368 int retval;
369
370 might_fault();
371 retval = flush_user_asm(mem, len);
372 mb_incoherent();
373 return retval;
374 }
375
flush_user(void __user * mem,unsigned long len)376 static inline unsigned long __must_check flush_user(
377 void __user *mem, unsigned long len)
378 {
379 if (access_ok(VERIFY_WRITE, mem, len))
380 return __flush_user(mem, len);
381 return len;
382 }
383
384 /**
385 * finv_user: - Flush-inval a block of memory in user space from cache.
386 * @mem: Destination address, in user space.
387 * @len: Number of bytes to invalidate.
388 *
389 * Returns number of bytes that could not be flush-invalidated.
390 * On success, this will be zero.
391 */
392 extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
__finv_user(void __user * mem,unsigned long len)393 static inline unsigned long __must_check __finv_user(
394 void __user *mem, unsigned long len)
395 {
396 int retval;
397
398 might_fault();
399 retval = finv_user_asm(mem, len);
400 mb_incoherent();
401 return retval;
402 }
finv_user(void __user * mem,unsigned long len)403 static inline unsigned long __must_check finv_user(
404 void __user *mem, unsigned long len)
405 {
406 if (access_ok(VERIFY_WRITE, mem, len))
407 return __finv_user(mem, len);
408 return len;
409 }
410
411 #endif /* _ASM_TILE_UACCESS_H */
412