4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
8 * OpenRISC implementation:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
19 #ifndef __ASM_OPENRISC_UACCESS_H
20 #define __ASM_OPENRISC_UACCESS_H
23 * User space memory access functions
25 #include <linux/prefetch.h>
26 #include <linux/string.h>
28 #include <asm/extable.h>
31 * The fs value determines whether argument validity checking should be
32 * performed or not. If get_fs() == USER_DS, checking is performed, with
33 * get_fs() == KERNEL_DS, checking is bypassed.
35 * For historical reasons, these macros are grossly misnamed.
38 /* addr_limit is the maximum accessible address for the task. we misuse
39 * the KERNEL_DS and USER_DS values to both assign and compare the
40 * addr_limit values through the equally misnamed get/set_fs macros.
44 #define KERNEL_DS (~0UL)
46 #define USER_DS (TASK_SIZE)
47 #define get_fs() (current_thread_info()->addr_limit)
48 #define set_fs(x) (current_thread_info()->addr_limit = (x))
50 #define segment_eq(a, b) ((a) == (b))
52 /* Ensure that the range from addr to addr+size is all within the process'
55 #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
57 /* Ensure that addr is below task's addr_limit */
58 #define __addr_ok(addr) ((unsigned long) addr < get_fs())
60 #define access_ok(addr, size) \
62 unsigned long __ao_addr = (unsigned long)(addr); \
63 unsigned long __ao_size = (unsigned long)(size); \
64 __range_ok(__ao_addr, __ao_size); \
68 * These are the main single-value transfer routines. They automatically
69 * use the right size if we just have the right pointer type.
71 * This gets kind of ugly. We want to return _two_ values in "get_user()"
72 * and yet we don't want to do any pointers, because that is too much
73 * of a performance impact. Thus we have a few rather ugly macros here,
74 * and hide all the uglyness from the user.
76 * The "__xxx" versions of the user access functions are versions that
77 * do not verify the address space, that must have been done previously
78 * with a separate "access_ok()" call (this is used when we do multiple
79 * accesses to the same area of user memory).
81 * As we use the same address space for kernel and user data on the
82 * PowerPC, we can just do these as direct assignments. (Of course, the
83 * exception handling means that it's no longer "just"...)
85 #define get_user(x, ptr) \
86 __get_user_check((x), (ptr), sizeof(*(ptr)))
87 #define put_user(x, ptr) \
88 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
90 #define __get_user(x, ptr) \
91 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
92 #define __put_user(x, ptr) \
93 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
95 extern long __put_user_bad(void);
97 #define __put_user_nocheck(x, ptr, size) \
100 __put_user_size((x), (ptr), (size), __pu_err); \
104 #define __put_user_check(x, ptr, size) \
106 long __pu_err = -EFAULT; \
107 __typeof__(*(ptr)) *__pu_addr = (ptr); \
108 if (access_ok(__pu_addr, size)) \
109 __put_user_size((x), __pu_addr, (size), __pu_err); \
113 #define __put_user_size(x, ptr, size, retval) \
117 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
118 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
119 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
120 case 8: __put_user_asm2(x, ptr, retval); break; \
121 default: __put_user_bad(); \
125 struct __large_struct {
126 unsigned long buf[100];
128 #define __m(x) (*(struct __large_struct *)(x))
131 * We don't tell gcc that we are accessing memory, but this is OK
132 * because we do not write to any memory gcc knows about, so there
133 * are no aliasing issues.
135 #define __put_user_asm(x, addr, err, op) \
136 __asm__ __volatile__( \
137 "1: "op" 0(%2),%1\n" \
139 ".section .fixup,\"ax\"\n" \
140 "3: l.addi %0,r0,%3\n" \
144 ".section __ex_table,\"a\"\n" \
149 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
151 #define __put_user_asm2(x, addr, err) \
152 __asm__ __volatile__( \
153 "1: l.sw 0(%2),%1\n" \
154 "2: l.sw 4(%2),%H1\n" \
156 ".section .fixup,\"ax\"\n" \
157 "4: l.addi %0,r0,%3\n" \
161 ".section __ex_table,\"a\"\n" \
167 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
169 #define __get_user_nocheck(x, ptr, size) \
171 long __gu_err, __gu_val; \
172 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
173 (x) = (__force __typeof__(*(ptr)))__gu_val; \
177 #define __get_user_check(x, ptr, size) \
179 long __gu_err = -EFAULT, __gu_val = 0; \
180 const __typeof__(*(ptr)) * __gu_addr = (ptr); \
181 if (access_ok(__gu_addr, size)) \
182 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
183 (x) = (__force __typeof__(*(ptr)))__gu_val; \
187 extern long __get_user_bad(void);
189 #define __get_user_size(x, ptr, size, retval) \
193 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
194 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
195 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
196 case 8: __get_user_asm2(x, ptr, retval); break; \
197 default: (x) = __get_user_bad(); \
201 #define __get_user_asm(x, addr, err, op) \
202 __asm__ __volatile__( \
203 "1: "op" %1,0(%2)\n" \
205 ".section .fixup,\"ax\"\n" \
206 "3: l.addi %0,r0,%3\n" \
207 " l.addi %1,r0,0\n" \
211 ".section __ex_table,\"a\"\n" \
215 : "=r"(err), "=r"(x) \
216 : "r"(addr), "i"(-EFAULT), "0"(err))
218 #define __get_user_asm2(x, addr, err) \
219 __asm__ __volatile__( \
220 "1: l.lwz %1,0(%2)\n" \
221 "2: l.lwz %H1,4(%2)\n" \
223 ".section .fixup,\"ax\"\n" \
224 "4: l.addi %0,r0,%3\n" \
225 " l.addi %1,r0,0\n" \
226 " l.addi %H1,r0,0\n" \
230 ".section __ex_table,\"a\"\n" \
235 : "=r"(err), "=&r"(x) \
236 : "r"(addr), "i"(-EFAULT), "0"(err))
238 /* more complex routines */
240 extern unsigned long __must_check
241 __copy_tofrom_user(void *to, const void *from, unsigned long size);
242 static inline unsigned long
243 raw_copy_from_user(void *to, const void __user *from, unsigned long size)
245 return __copy_tofrom_user(to, (__force const void *)from, size);
247 static inline unsigned long
248 raw_copy_to_user(void *to, const void __user *from, unsigned long size)
250 return __copy_tofrom_user((__force void *)to, from, size);
252 #define INLINE_COPY_FROM_USER
253 #define INLINE_COPY_TO_USER
255 extern unsigned long __clear_user(void *addr, unsigned long size);
257 static inline __must_check unsigned long
258 clear_user(void *addr, unsigned long size)
260 if (likely(access_ok(addr, size)))
261 size = __clear_user(addr, size);
265 #define user_addr_max() \
266 (uaccess_kernel() ? ~0UL : TASK_SIZE)
268 extern long strncpy_from_user(char *dest, const char __user *src, long count);
270 extern __must_check long strnlen_user(const char __user *str, long n);
272 #endif /* __ASM_OPENRISC_UACCESS_H */