1#ifndef __PARISC_UACCESS_H
2#define __PARISC_UACCESS_H
3
4/*
5 * User space memory access functions
6 */
7#include <asm/page.h>
8#include <asm/cache.h>
9#include <asm/errno.h>
10#include <asm-generic/uaccess-unaligned.h>
11
12#include <linux/bug.h>
13
14#define VERIFY_READ 0
15#define VERIFY_WRITE 1
16
17#define KERNEL_DS	((mm_segment_t){0})
18#define USER_DS 	((mm_segment_t){1})
19
20#define segment_eq(a, b) ((a).seg == (b).seg)
21
22#define get_ds()	(KERNEL_DS)
23#define get_fs()	(current_thread_info()->addr_limit)
24#define set_fs(x)	(current_thread_info()->addr_limit = (x))
25
26/*
27 * Note that since kernel addresses are in a separate address space on
28 * parisc, we don't need to do anything for access_ok().
29 * We just let the page fault handler do the right thing. This also means
30 * that put_user is the same as __put_user, etc.
31 */
32
33static inline long access_ok(int type, const void __user * addr,
34		unsigned long size)
35{
36	return 1;
37}
38
39#define put_user __put_user
40#define get_user __get_user
41
42#if !defined(CONFIG_64BIT)
43#define LDD_KERNEL(ptr)		BUILD_BUG()
44#define LDD_USER(ptr)		BUILD_BUG()
45#define STD_KERNEL(x, ptr)	__put_kernel_asm64(x, ptr)
46#define STD_USER(x, ptr)	__put_user_asm64(x, ptr)
47#define ASM_WORD_INSN		".word\t"
48#else
49#define LDD_KERNEL(ptr)		__get_kernel_asm("ldd", ptr)
50#define LDD_USER(ptr)		__get_user_asm("ldd", ptr)
51#define STD_KERNEL(x, ptr)	__put_kernel_asm("std", x, ptr)
52#define STD_USER(x, ptr)	__put_user_asm("std", x, ptr)
53#define ASM_WORD_INSN		".dword\t"
54#endif
55
56/*
57 * The exception table contains two values: the first is an address
58 * for an instruction that is allowed to fault, and the second is
59 * the address to the fixup routine. Even on a 64bit kernel we could
60 * use a 32bit (unsigned int) address here.
61 */
62
63struct exception_table_entry {
64	unsigned long insn;	/* address of insn that is allowed to fault. */
65	unsigned long fixup;	/* fixup routine */
66};
67
68#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
69	".section __ex_table,\"aw\"\n"			   \
70	ASM_WORD_INSN #fault_addr ", " #except_addr "\n\t" \
71	".previous\n"
72
73/*
74 * The page fault handler stores, in a per-cpu area, the following information
75 * if a fixup routine is available.
76 */
77struct exception_data {
78	unsigned long fault_ip;
79	unsigned long fault_gp;
80	unsigned long fault_space;
81	unsigned long fault_addr;
82};
83
84#define __get_user(x, ptr)                               \
85({                                                       \
86	register long __gu_err __asm__ ("r8") = 0;       \
87	register long __gu_val __asm__ ("r9") = 0;       \
88							 \
89	if (segment_eq(get_fs(), KERNEL_DS)) {           \
90	    switch (sizeof(*(ptr))) {                    \
91	    case 1: __get_kernel_asm("ldb", ptr); break; \
92	    case 2: __get_kernel_asm("ldh", ptr); break; \
93	    case 4: __get_kernel_asm("ldw", ptr); break; \
94	    case 8: LDD_KERNEL(ptr); break;		 \
95	    default: BUILD_BUG(); break;		 \
96	    }                                            \
97	}                                                \
98	else {                                           \
99	    switch (sizeof(*(ptr))) {                    \
100	    case 1: __get_user_asm("ldb", ptr); break;   \
101	    case 2: __get_user_asm("ldh", ptr); break;   \
102	    case 4: __get_user_asm("ldw", ptr); break;   \
103	    case 8: LDD_USER(ptr);  break;		 \
104	    default: BUILD_BUG(); break;		 \
105	    }                                            \
106	}                                                \
107							 \
108	(x) = (__force __typeof__(*(ptr))) __gu_val;	 \
109	__gu_err;                                        \
110})
111
112#define __get_kernel_asm(ldx, ptr)                      \
113	__asm__("\n1:\t" ldx "\t0(%2),%0\n\t"		\
114		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
115		: "=r"(__gu_val), "=r"(__gu_err)        \
116		: "r"(ptr), "1"(__gu_err)		\
117		: "r1");
118
119#define __get_user_asm(ldx, ptr)                        \
120	__asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t"	\
121		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
122		: "=r"(__gu_val), "=r"(__gu_err)        \
123		: "r"(ptr), "1"(__gu_err)		\
124		: "r1");
125
126#define __put_user(x, ptr)                                      \
127({								\
128	register long __pu_err __asm__ ("r8") = 0;      	\
129        __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);	\
130								\
131	if (segment_eq(get_fs(), KERNEL_DS)) {                  \
132	    switch (sizeof(*(ptr))) {                           \
133	    case 1: __put_kernel_asm("stb", __x, ptr); break;   \
134	    case 2: __put_kernel_asm("sth", __x, ptr); break;   \
135	    case 4: __put_kernel_asm("stw", __x, ptr); break;   \
136	    case 8: STD_KERNEL(__x, ptr); break;		\
137	    default: BUILD_BUG(); break;			\
138	    }                                                   \
139	}                                                       \
140	else {                                                  \
141	    switch (sizeof(*(ptr))) {                           \
142	    case 1: __put_user_asm("stb", __x, ptr); break;     \
143	    case 2: __put_user_asm("sth", __x, ptr); break;     \
144	    case 4: __put_user_asm("stw", __x, ptr); break;     \
145	    case 8: STD_USER(__x, ptr); break;			\
146	    default: BUILD_BUG(); break;			\
147	    }                                                   \
148	}                                                       \
149								\
150	__pu_err;						\
151})
152
153/*
154 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
155 * instead of writing. This is because they do not write to any memory
156 * gcc knows about, so there are no aliasing issues. These macros must
157 * also be aware that "fixup_put_user_skip_[12]" are executed in the
158 * context of the fault, and any registers used there must be listed
159 * as clobbers. In this case only "r1" is used by the current routines.
160 * r8/r9 are already listed as err/val.
161 */
162
163#define __put_kernel_asm(stx, x, ptr)                       \
164	__asm__ __volatile__ (                              \
165		"\n1:\t" stx "\t%2,0(%1)\n\t"		    \
166		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
167		: "=r"(__pu_err)                            \
168		: "r"(ptr), "r"(x), "0"(__pu_err)	    \
169	    	: "r1")
170
171#define __put_user_asm(stx, x, ptr)                         \
172	__asm__ __volatile__ (                              \
173		"\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t"	    \
174		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
175		: "=r"(__pu_err)                            \
176		: "r"(ptr), "r"(x), "0"(__pu_err)	    \
177		: "r1")
178
179
180#if !defined(CONFIG_64BIT)
181
182#define __put_kernel_asm64(__val, ptr) do {		    \
183	__asm__ __volatile__ (				    \
184		"\n1:\tstw %2,0(%1)"			    \
185		"\n2:\tstw %R2,4(%1)\n\t"		    \
186		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
187		ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
188		: "=r"(__pu_err)                            \
189		: "r"(ptr), "r"(__val), "0"(__pu_err) \
190		: "r1");				    \
191} while (0)
192
193#define __put_user_asm64(__val, ptr) do {	    	    \
194	__asm__ __volatile__ (				    \
195		"\n1:\tstw %2,0(%%sr3,%1)"		    \
196		"\n2:\tstw %R2,4(%%sr3,%1)\n\t"		    \
197		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
198		ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
199		: "=r"(__pu_err)                            \
200		: "r"(ptr), "r"(__val), "0"(__pu_err) \
201		: "r1");				    \
202} while (0)
203
204#endif /* !defined(CONFIG_64BIT) */
205
206
207/*
208 * Complex access routines -- external declarations
209 */
210
211extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
212extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
213extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
214extern long strncpy_from_user(char *, const char __user *, long);
215extern unsigned lclear_user(void __user *, unsigned long);
216extern long lstrnlen_user(const char __user *, long);
217/*
218 * Complex access routines -- macros
219 */
220#define user_addr_max() (~0UL)
221
222#define strnlen_user lstrnlen_user
223#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
224#define clear_user lclear_user
225#define __clear_user lclear_user
226
227unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
228#define __copy_to_user copy_to_user
229unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
230unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
231#define __copy_in_user copy_in_user
232#define __copy_to_user_inatomic __copy_to_user
233#define __copy_from_user_inatomic __copy_from_user
234
235extern void copy_from_user_overflow(void)
236#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
237        __compiletime_error("copy_from_user() buffer size is not provably correct")
238#else
239        __compiletime_warning("copy_from_user() buffer size is not provably correct")
240#endif
241;
242
243static inline unsigned long __must_check copy_from_user(void *to,
244                                          const void __user *from,
245                                          unsigned long n)
246{
247        int sz = __compiletime_object_size(to);
248        int ret = -EFAULT;
249
250        if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
251                ret = __copy_from_user(to, from, n);
252        else
253                copy_from_user_overflow();
254
255        return ret;
256}
257
258struct pt_regs;
259int fixup_exception(struct pt_regs *regs);
260
261#endif /* __PARISC_UACCESS_H */
262