1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ALPHA_UACCESS_H
3#define __ALPHA_UACCESS_H
4
5#include <asm-generic/access_ok.h>
6/*
7 * These are the main single-value transfer routines.  They automatically
8 * use the right size if we just have the right pointer type.
9 *
10 * As the alpha uses the same address space for kernel and user
11 * data, we can just do these as direct assignments.  (Of course, the
12 * exception handling means that it's no longer "just"...)
13 *
14 * Careful to not
15 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
16 * (b) require any knowledge of processes at this stage
17 */
18#define put_user(x, ptr) \
19  __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
20#define get_user(x, ptr) \
21  __get_user_check((x), (ptr), sizeof(*(ptr)))
22
23/*
24 * The "__xxx" versions do not do address space checking, useful when
25 * doing multiple accesses to the same area (the programmer has to do the
26 * checks by hand with "access_ok()")
27 */
28#define __put_user(x, ptr) \
29  __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
30#define __get_user(x, ptr) \
31  __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
32
33/*
34 * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
35 * encode the bits we need for resolving the exception.  See the
36 * more extensive comments with fixup_inline_exception below for
37 * more information.
38 */
39#define EXC(label,cont,res,err)				\
40	".section __ex_table,\"a\"\n"			\
41	"	.long "#label"-.\n"			\
42	"	lda "#res","#cont"-"#label"("#err")\n"	\
43	".previous\n"
44
45extern void __get_user_unknown(void);
46
47#define __get_user_nocheck(x, ptr, size)			\
48({								\
49	long __gu_err = 0;					\
50	unsigned long __gu_val;					\
51	__chk_user_ptr(ptr);					\
52	switch (size) {						\
53	  case 1: __get_user_8(ptr); break;			\
54	  case 2: __get_user_16(ptr); break;			\
55	  case 4: __get_user_32(ptr); break;			\
56	  case 8: __get_user_64(ptr); break;			\
57	  default: __get_user_unknown(); break;			\
58	}							\
59	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
60	__gu_err;						\
61})
62
63#define __get_user_check(x, ptr, size)				\
64({								\
65	long __gu_err = -EFAULT;				\
66	unsigned long __gu_val = 0;				\
67	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
68	if (__access_ok(__gu_addr, size)) {			\
69		__gu_err = 0;					\
70		switch (size) {					\
71		  case 1: __get_user_8(__gu_addr); break;	\
72		  case 2: __get_user_16(__gu_addr); break;	\
73		  case 4: __get_user_32(__gu_addr); break;	\
74		  case 8: __get_user_64(__gu_addr); break;	\
75		  default: __get_user_unknown(); break;		\
76		}						\
77	}							\
78	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
79	__gu_err;						\
80})
81
82struct __large_struct { unsigned long buf[100]; };
83#define __m(x) (*(struct __large_struct __user *)(x))
84
85#define __get_user_64(addr)				\
86	__asm__("1: ldq %0,%2\n"			\
87	"2:\n"						\
88	EXC(1b,2b,%0,%1)				\
89		: "=r"(__gu_val), "=r"(__gu_err)	\
90		: "m"(__m(addr)), "1"(__gu_err))
91
92#define __get_user_32(addr)				\
93	__asm__("1: ldl %0,%2\n"			\
94	"2:\n"						\
95	EXC(1b,2b,%0,%1)				\
96		: "=r"(__gu_val), "=r"(__gu_err)	\
97		: "m"(__m(addr)), "1"(__gu_err))
98
99#ifdef __alpha_bwx__
100/* Those lucky bastards with ev56 and later CPUs can do byte/word moves.  */
101
102#define __get_user_16(addr)				\
103	__asm__("1: ldwu %0,%2\n"			\
104	"2:\n"						\
105	EXC(1b,2b,%0,%1)				\
106		: "=r"(__gu_val), "=r"(__gu_err)	\
107		: "m"(__m(addr)), "1"(__gu_err))
108
109#define __get_user_8(addr)				\
110	__asm__("1: ldbu %0,%2\n"			\
111	"2:\n"						\
112	EXC(1b,2b,%0,%1)				\
113		: "=r"(__gu_val), "=r"(__gu_err)	\
114		: "m"(__m(addr)), "1"(__gu_err))
115#else
116/* Unfortunately, we can't get an unaligned access trap for the sub-word
117   load, so we have to do a general unaligned operation.  */
118
119#define __get_user_16(addr)						\
120{									\
121	long __gu_tmp;							\
122	__asm__("1: ldq_u %0,0(%3)\n"					\
123	"2:	ldq_u %1,1(%3)\n"					\
124	"	extwl %0,%3,%0\n"					\
125	"	extwh %1,%3,%1\n"					\
126	"	or %0,%1,%0\n"						\
127	"3:\n"								\
128	EXC(1b,3b,%0,%2)						\
129	EXC(2b,3b,%0,%2)						\
130		: "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err)	\
131		: "r"(addr), "2"(__gu_err));				\
132}
133
134#define __get_user_8(addr)						\
135	__asm__("1: ldq_u %0,0(%2)\n"					\
136	"	extbl %0,%2,%0\n"					\
137	"2:\n"								\
138	EXC(1b,2b,%0,%1)						\
139		: "=&r"(__gu_val), "=r"(__gu_err)			\
140		: "r"(addr), "1"(__gu_err))
141#endif
142
143extern void __put_user_unknown(void);
144
145#define __put_user_nocheck(x, ptr, size)			\
146({								\
147	long __pu_err = 0;					\
148	__chk_user_ptr(ptr);					\
149	switch (size) {						\
150	  case 1: __put_user_8(x, ptr); break;			\
151	  case 2: __put_user_16(x, ptr); break;			\
152	  case 4: __put_user_32(x, ptr); break;			\
153	  case 8: __put_user_64(x, ptr); break;			\
154	  default: __put_user_unknown(); break;			\
155	}							\
156	__pu_err;						\
157})
158
159#define __put_user_check(x, ptr, size)				\
160({								\
161	long __pu_err = -EFAULT;				\
162	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
163	if (__access_ok(__pu_addr, size)) {			\
164		__pu_err = 0;					\
165		switch (size) {					\
166		  case 1: __put_user_8(x, __pu_addr); break;	\
167		  case 2: __put_user_16(x, __pu_addr); break;	\
168		  case 4: __put_user_32(x, __pu_addr); break;	\
169		  case 8: __put_user_64(x, __pu_addr); break;	\
170		  default: __put_user_unknown(); break;		\
171		}						\
172	}							\
173	__pu_err;						\
174})
175
176/*
177 * The "__put_user_xx()" macros tell gcc they read from memory
178 * instead of writing: this is because they do not write to
179 * any memory gcc knows about, so there are no aliasing issues
180 */
181#define __put_user_64(x, addr)					\
182__asm__ __volatile__("1: stq %r2,%1\n"				\
183	"2:\n"							\
184	EXC(1b,2b,$31,%0)					\
185		: "=r"(__pu_err)				\
186		: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
187
188#define __put_user_32(x, addr)					\
189__asm__ __volatile__("1: stl %r2,%1\n"				\
190	"2:\n"							\
191	EXC(1b,2b,$31,%0)					\
192		: "=r"(__pu_err)				\
193		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
194
195#ifdef __alpha_bwx__
196/* Those lucky bastards with ev56 and later CPUs can do byte/word moves.  */
197
198#define __put_user_16(x, addr)					\
199__asm__ __volatile__("1: stw %r2,%1\n"				\
200	"2:\n"							\
201	EXC(1b,2b,$31,%0)					\
202		: "=r"(__pu_err)				\
203		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
204
205#define __put_user_8(x, addr)					\
206__asm__ __volatile__("1: stb %r2,%1\n"				\
207	"2:\n"							\
208	EXC(1b,2b,$31,%0)					\
209		: "=r"(__pu_err)				\
210		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
211#else
212/* Unfortunately, we can't get an unaligned access trap for the sub-word
213   write, so we have to do a general unaligned operation.  */
214
215#define __put_user_16(x, addr)					\
216{								\
217	long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4;	\
218	__asm__ __volatile__(					\
219	"1:	ldq_u %2,1(%5)\n"				\
220	"2:	ldq_u %1,0(%5)\n"				\
221	"	inswh %6,%5,%4\n"				\
222	"	inswl %6,%5,%3\n"				\
223	"	mskwh %2,%5,%2\n"				\
224	"	mskwl %1,%5,%1\n"				\
225	"	or %2,%4,%2\n"					\
226	"	or %1,%3,%1\n"					\
227	"3:	stq_u %2,1(%5)\n"				\
228	"4:	stq_u %1,0(%5)\n"				\
229	"5:\n"							\
230	EXC(1b,5b,$31,%0)					\
231	EXC(2b,5b,$31,%0)					\
232	EXC(3b,5b,$31,%0)					\
233	EXC(4b,5b,$31,%0)					\
234		: "=r"(__pu_err), "=&r"(__pu_tmp1), 		\
235		  "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), 		\
236		  "=&r"(__pu_tmp4)				\
237		: "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
238}
239
240#define __put_user_8(x, addr)					\
241{								\
242	long __pu_tmp1, __pu_tmp2;				\
243	__asm__ __volatile__(					\
244	"1:	ldq_u %1,0(%4)\n"				\
245	"	insbl %3,%4,%2\n"				\
246	"	mskbl %1,%4,%1\n"				\
247	"	or %1,%2,%1\n"					\
248	"2:	stq_u %1,0(%4)\n"				\
249	"3:\n"							\
250	EXC(1b,3b,$31,%0)					\
251	EXC(2b,3b,$31,%0)					\
252		: "=r"(__pu_err), 				\
253	  	  "=&r"(__pu_tmp1), "=&r"(__pu_tmp2)		\
254		: "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
255}
256#endif
257
258
259/*
260 * Complex access routines
261 */
262
263extern long __copy_user(void *to, const void *from, long len);
264
265static inline unsigned long
266raw_copy_from_user(void *to, const void __user *from, unsigned long len)
267{
268	return __copy_user(to, (__force const void *)from, len);
269}
270
271static inline unsigned long
272raw_copy_to_user(void __user *to, const void *from, unsigned long len)
273{
274	return __copy_user((__force void *)to, from, len);
275}
276
277extern long __clear_user(void __user *to, long len);
278
279static inline long
280clear_user(void __user *to, long len)
281{
282	if (__access_ok(to, len))
283		len = __clear_user(to, len);
284	return len;
285}
286
287extern long strncpy_from_user(char *dest, const char __user *src, long count);
288extern __must_check long strnlen_user(const char __user *str, long n);
289
290#include <asm/extable.h>
291
292#endif /* __ALPHA_UACCESS_H */
293