File: /usr/src/linux/include/asm-parisc/uaccess.h
1 #ifndef __PARISC_UACCESS_H
2 #define __PARISC_UACCESS_H
3
4 /*
5 * User space memory access functions
6 */
7 #include <linux/sched.h>
8 #include <asm/page.h>
9 #include <asm/system.h>
10 #include <asm/cache.h>
11
12 #define VERIFY_READ 0
13 #define VERIFY_WRITE 1
14
15 #define KERNEL_DS ((mm_segment_t){0})
16 #define USER_DS ((mm_segment_t){1})
17
18 #define segment_eq(a,b) ((a).seg == (b).seg)
19
20 #define get_ds() (KERNEL_DS)
21 #define get_fs() (current->addr_limit)
22 #define set_fs(x) (current->addr_limit = (x))
23
24 /*
25 * Note that since kernel addresses are in a separate address space on
26 * parisc, we don't need to do anything for access_ok() or verify_area().
27 * We just let the page fault handler do the right thing. This also means
28 * that put_user is the same as __put_user, etc.
29 */
30
31 #define access_ok(type,addr,size) (1)
32 #define verify_area(type,addr,size) (0)
33
34 #define put_user __put_user
35 #define get_user __get_user
36
37 /*
38 * The exception table contains two values: the first is an address
39 * for an instruction that is allowed to fault, and the second is
40 * the number of bytes to skip if a fault occurs. We also support in
41 * two bit flags: 0x2 tells the exception handler to clear register
42 * r9 and 0x1 tells the exception handler to put -EFAULT in r8.
43 * This allows us to handle the simple cases for put_user and
44 * get_user without having to have .fixup sections.
45 */
46
47 struct exception_table_entry {
48 unsigned long addr; /* address of insn that is allowed to fault. */
49 int skip; /* pcoq skip | r9 clear flag | r8 -EFAULT flag */
50 };
51
52 extern const struct exception_table_entry
53 *search_exception_table(unsigned long addr);
54
55 #define __get_user(x,ptr) \
56 ({ \
57 register long __gu_err __asm__ ("r8") = 0; \
58 register long __gu_val __asm__ ("r9") = 0; \
59 \
60 if (segment_eq(get_fs(),KERNEL_DS)) { \
61 switch (sizeof(*(ptr))) { \
62 case 1: __get_kernel_asm("ldb",ptr); break; \
63 case 2: __get_kernel_asm("ldh",ptr); break; \
64 case 4: __get_kernel_asm("ldw",ptr); break; \
65 case 8: __get_kernel_asm("ldd",ptr); break; \
66 default: BUG(); break; \
67 } \
68 } \
69 else { \
70 switch (sizeof(*(ptr))) { \
71 case 1: __get_user_asm("ldb",ptr); break; \
72 case 2: __get_user_asm("ldh",ptr); break; \
73 case 4: __get_user_asm("ldw",ptr); break; \
74 case 8: __get_user_asm("ldd",ptr); break; \
75 default: BUG(); break; \
76 } \
77 } \
78 \
79 (x) = (__typeof__(*(ptr))) __gu_val; \
80 __gu_err; \
81 })
82
83 #define __get_kernel_asm(ldx,ptr) \
84 __asm__("\n1:\t" ldx "\t0(%2),%0\n" \
85 "2:\n" \
86 "\t.section __ex_table,\"a\"\n" \
87 "\t.word\t1b\n" \
88 "\t.word\t(2b-1b)+3\n" \
89 "\t.previous" \
90 : "=r"(__gu_val), "=r"(__gu_err) \
91 : "r"(ptr), "1"(__gu_err));
92
93 #define __get_user_asm(ldx,ptr) \
94 __asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n" \
95 "2:\n" \
96 "\t.section __ex_table,\"a\"\n" \
97 "\t.word\t1b\n" \
98 "\t.word\t(2b-1b)+3\n" \
99 "\t.previous" \
100 : "=r"(__gu_val), "=r"(__gu_err) \
101 : "r"(ptr), "1"(__gu_err));
102
103
104 #define __put_user(x,ptr) \
105 ({ \
106 register long __pu_err __asm__ ("r8") = 0; \
107 \
108 if (segment_eq(get_fs(),KERNEL_DS)) { \
109 switch (sizeof(*(ptr))) { \
110 case 1: __put_kernel_asm("stb",x,ptr); break; \
111 case 2: __put_kernel_asm("sth",x,ptr); break; \
112 case 4: __put_kernel_asm("stw",x,ptr); break; \
113 case 8: __put_kernel_asm("std",x,ptr); break; \
114 default: BUG(); break; \
115 } \
116 } \
117 else { \
118 switch (sizeof(*(ptr))) { \
119 case 1: __put_user_asm("stb",x,ptr); break; \
120 case 2: __put_user_asm("sth",x,ptr); break; \
121 case 4: __put_user_asm("stw",x,ptr); break; \
122 case 8: __put_user_asm("std",x,ptr); break; \
123 default: BUG(); break; \
124 } \
125 } \
126 \
127 __pu_err; \
128 })
129
130 /*
131 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
132 * instead of writing. This is because they do not write to any memory
133 * gcc knows about, so there are no aliasing issues.
134 */
135
136 #define __put_kernel_asm(stx,x,ptr) \
137 __asm__ __volatile__ ( \
138 "\n1:\t" stx "\t%2,0(%1)\n" \
139 "2:\n" \
140 "\t.section __ex_table,\"a\"\n" \
141 "\t.word\t1b\n" \
142 "\t.word\t(2b-1b)+1\n" \
143 "\t.previous" \
144 : "=r"(__pu_err) \
145 : "r"(ptr), "r"(x), "0"(__pu_err))
146
147 #define __put_user_asm(stx,x,ptr) \
148 __asm__ __volatile__ ( \
149 "\n1:\t" stx "\t%2,0(%%sr3,%1)\n" \
150 "2:\n" \
151 "\t.section __ex_table,\"a\"\n" \
152 "\t.word\t1b\n" \
153 "\t.word\t(2b-1b)+1\n" \
154 "\t.previous" \
155 : "=r"(__pu_err) \
156 : "r"(ptr), "r"(x), "0"(__pu_err))
157
158
159 /*
160 * Complex access routines -- external declarations
161 */
162
163 extern unsigned long lcopy_to_user(void *, const void *, unsigned long);
164 extern unsigned long lcopy_from_user(void *, const void *, unsigned long);
165 extern long lstrncpy_from_user(char *, const char *, long);
166 extern unsigned lclear_user(void *,unsigned long);
167 extern long lstrnlen_user(const char *,long);
168
169 /*
170 * Complex access routines -- macros
171 */
172
173 #define strncpy_from_user lstrncpy_from_user
174 #define strnlen_user lstrnlen_user
175 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
176 #define clear_user lclear_user
177
178 #define copy_from_user lcopy_from_user
179 #define __copy_from_user lcopy_from_user
180 #define copy_to_user lcopy_to_user
181 #define __copy_to_user lcopy_to_user
182
183 #define copy_to_user_ret(to,from,n,retval) \
184 ({ if (lcopy_to_user(to,from,n)) return retval; })
185
186 #define copy_from_user_ret(to,from,n,retval) \
187 ({ if (lcopy_from_user(to,from,n)) return retval; })
188
189 #endif /* __PARISC_UACCESS_H */
190