xref: /openbmc/linux/arch/arc/include/asm/uaccess.h (revision 63705da3)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  *
5  * vineetg: June 2010
6  *    -__clear_user( ) called multiple times during elf load was byte loop
7  *    converted to do as much word clear as possible.
8  *
9  * vineetg: Dec 2009
10  *    -Hand crafted constant propagation for "constant" copy sizes
11  *    -stock kernel shrunk by 33K at -O3
12  *
13  * vineetg: Sept 2009
14  *    -Added option to (UN)inline copy_(to|from)_user to reduce code sz
15  *    -kernel shrunk by 200K even at -O3 (gcc 4.2.1)
16  *    -Enabled when doing -Os
17  *
18  * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
19  */
20 
21 #ifndef _ASM_ARC_UACCESS_H
22 #define _ASM_ARC_UACCESS_H
23 
24 #include <linux/string.h>	/* for generic string functions */
25 
26 
27 #define __kernel_ok		(uaccess_kernel())
28 
29 /*
30  * Algorithmically, for __user_ok() we want do:
31  * 	(start < TASK_SIZE) && (start+len < TASK_SIZE)
32  * where TASK_SIZE could either be retrieved from thread_info->addr_limit or
33  * emitted directly in code.
34  *
35  * This can however be rewritten as follows:
36  *	(len <= TASK_SIZE) && (start+len < TASK_SIZE)
37  *
38  * Because it essentially checks if buffer end is within limit and @len is
39  * non-ngeative, which implies that buffer start will be within limit too.
40  *
41  * The reason for rewriting being, for majority of cases, @len is generally
42  * compile time constant, causing first sub-expression to be compile time
43  * subsumed.
44  *
45  * The second part would generate weird large LIMMs e.g. (0x6000_0000 - 0x10),
46  * so we check for TASK_SIZE using get_fs() since the addr_limit load from mem
47  * would already have been done at this call site for __kernel_ok()
48  *
49  */
50 #define __user_ok(addr, sz)	(((sz) <= TASK_SIZE) && \
51 				 ((addr) <= (get_fs() - (sz))))
52 #define __access_ok(addr, sz)	(unlikely(__kernel_ok) || \
53 				 likely(__user_ok((addr), (sz))))
54 
55 /*********** Single byte/hword/word copies ******************/
56 
57 #define __get_user_fn(sz, u, k)					\
58 ({								\
59 	long __ret = 0;	/* success by default */	\
60 	switch (sz) {						\
61 	case 1: __arc_get_user_one(*(k), u, "ldb", __ret); break;	\
62 	case 2: __arc_get_user_one(*(k), u, "ldw", __ret); break;	\
63 	case 4: __arc_get_user_one(*(k), u, "ld", __ret);  break;	\
64 	case 8: __arc_get_user_one_64(*(k), u, __ret);     break;	\
65 	}							\
66 	__ret;							\
67 })
68 
69 /*
70  * Returns 0 on success, -EFAULT if not.
71  * @ret already contains 0 - given that errors will be less likely
72  * (hence +r asm constraint below).
73  * In case of error, fixup code will make it -EFAULT
74  */
75 #define __arc_get_user_one(dst, src, op, ret)	\
76 	__asm__ __volatile__(                   \
77 	"1:	"op"    %1,[%2]\n"		\
78 	"2:	;nop\n"				\
79 	"	.section .fixup, \"ax\"\n"	\
80 	"	.align 4\n"			\
81 	"3:	# return -EFAULT\n"		\
82 	"	mov %0, %3\n"			\
83 	"	# zero out dst ptr\n"		\
84 	"	mov %1,  0\n"			\
85 	"	j   2b\n"			\
86 	"	.previous\n"			\
87 	"	.section __ex_table, \"a\"\n"	\
88 	"	.align 4\n"			\
89 	"	.word 1b,3b\n"			\
90 	"	.previous\n"			\
91 						\
92 	: "+r" (ret), "=r" (dst)		\
93 	: "r" (src), "ir" (-EFAULT))
94 
95 #define __arc_get_user_one_64(dst, src, ret)	\
96 	__asm__ __volatile__(                   \
97 	"1:	ld   %1,[%2]\n"			\
98 	"4:	ld  %R1,[%2, 4]\n"		\
99 	"2:	;nop\n"				\
100 	"	.section .fixup, \"ax\"\n"	\
101 	"	.align 4\n"			\
102 	"3:	# return -EFAULT\n"		\
103 	"	mov %0, %3\n"			\
104 	"	# zero out dst ptr\n"		\
105 	"	mov %1,  0\n"			\
106 	"	mov %R1, 0\n"			\
107 	"	j   2b\n"			\
108 	"	.previous\n"			\
109 	"	.section __ex_table, \"a\"\n"	\
110 	"	.align 4\n"			\
111 	"	.word 1b,3b\n"			\
112 	"	.word 4b,3b\n"			\
113 	"	.previous\n"			\
114 						\
115 	: "+r" (ret), "=r" (dst)		\
116 	: "r" (src), "ir" (-EFAULT))
117 
118 #define __put_user_fn(sz, u, k)					\
119 ({								\
120 	long __ret = 0;	/* success by default */	\
121 	switch (sz) {						\
122 	case 1: __arc_put_user_one(*(k), u, "stb", __ret); break;	\
123 	case 2: __arc_put_user_one(*(k), u, "stw", __ret); break;	\
124 	case 4: __arc_put_user_one(*(k), u, "st", __ret);  break;	\
125 	case 8: __arc_put_user_one_64(*(k), u, __ret);     break;	\
126 	}							\
127 	__ret;							\
128 })
129 
130 #define __arc_put_user_one(src, dst, op, ret)	\
131 	__asm__ __volatile__(                   \
132 	"1:	"op"    %1,[%2]\n"		\
133 	"2:	;nop\n"				\
134 	"	.section .fixup, \"ax\"\n"	\
135 	"	.align 4\n"			\
136 	"3:	mov %0, %3\n"			\
137 	"	j   2b\n"			\
138 	"	.previous\n"			\
139 	"	.section __ex_table, \"a\"\n"	\
140 	"	.align 4\n"			\
141 	"	.word 1b,3b\n"			\
142 	"	.previous\n"			\
143 						\
144 	: "+r" (ret)				\
145 	: "r" (src), "r" (dst), "ir" (-EFAULT))
146 
147 #define __arc_put_user_one_64(src, dst, ret)	\
148 	__asm__ __volatile__(                   \
149 	"1:	st   %1,[%2]\n"			\
150 	"4:	st  %R1,[%2, 4]\n"		\
151 	"2:	;nop\n"				\
152 	"	.section .fixup, \"ax\"\n"	\
153 	"	.align 4\n"			\
154 	"3:	mov %0, %3\n"			\
155 	"	j   2b\n"			\
156 	"	.previous\n"			\
157 	"	.section __ex_table, \"a\"\n"	\
158 	"	.align 4\n"			\
159 	"	.word 1b,3b\n"			\
160 	"	.word 4b,3b\n"			\
161 	"	.previous\n"			\
162 						\
163 	: "+r" (ret)				\
164 	: "r" (src), "r" (dst), "ir" (-EFAULT))
165 
166 
167 static inline unsigned long
168 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
169 {
170 	long res = 0;
171 	char val;
172 	unsigned long tmp1, tmp2, tmp3, tmp4;
173 	unsigned long orig_n = n;
174 
175 	if (n == 0)
176 		return 0;
177 
178 	/* unaligned */
179 	if (((unsigned long)to & 0x3) || ((unsigned long)from & 0x3)) {
180 
181 		unsigned char tmp;
182 
183 		__asm__ __volatile__ (
184 		"	mov.f   lp_count, %0		\n"
185 		"	lpnz 2f				\n"
186 		"1:	ldb.ab  %1, [%3, 1]		\n"
187 		"	stb.ab  %1, [%2, 1]		\n"
188 		"	sub     %0,%0,1			\n"
189 		"2:	;nop				\n"
190 		"	.section .fixup, \"ax\"		\n"
191 		"	.align 4			\n"
192 		"3:	j   2b				\n"
193 		"	.previous			\n"
194 		"	.section __ex_table, \"a\"	\n"
195 		"	.align 4			\n"
196 		"	.word   1b, 3b			\n"
197 		"	.previous			\n"
198 
199 		: "+r" (n),
200 		/*
201 		 * Note as an '&' earlyclobber operand to make sure the
202 		 * temporary register inside the loop is not the same as
203 		 *  FROM or TO.
204 		*/
205 		  "=&r" (tmp), "+r" (to), "+r" (from)
206 		:
207 		: "lp_count", "memory");
208 
209 		return n;
210 	}
211 
212 	/*
213 	 * Hand-crafted constant propagation to reduce code sz of the
214 	 * laddered copy 16x,8,4,2,1
215 	 */
216 	if (__builtin_constant_p(orig_n)) {
217 		res = orig_n;
218 
219 		if (orig_n / 16) {
220 			orig_n = orig_n % 16;
221 
222 			__asm__ __volatile__(
223 			"	lsr   lp_count, %7,4		\n"
224 			"	lp    3f			\n"
225 			"1:	ld.ab   %3, [%2, 4]		\n"
226 			"11:	ld.ab   %4, [%2, 4]		\n"
227 			"12:	ld.ab   %5, [%2, 4]		\n"
228 			"13:	ld.ab   %6, [%2, 4]		\n"
229 			"	st.ab   %3, [%1, 4]		\n"
230 			"	st.ab   %4, [%1, 4]		\n"
231 			"	st.ab   %5, [%1, 4]		\n"
232 			"	st.ab   %6, [%1, 4]		\n"
233 			"	sub     %0,%0,16		\n"
234 			"3:	;nop				\n"
235 			"	.section .fixup, \"ax\"		\n"
236 			"	.align 4			\n"
237 			"4:	j   3b				\n"
238 			"	.previous			\n"
239 			"	.section __ex_table, \"a\"	\n"
240 			"	.align 4			\n"
241 			"	.word   1b, 4b			\n"
242 			"	.word   11b,4b			\n"
243 			"	.word   12b,4b			\n"
244 			"	.word   13b,4b			\n"
245 			"	.previous			\n"
246 			: "+r" (res), "+r"(to), "+r"(from),
247 			  "=r"(tmp1), "=r"(tmp2), "=r"(tmp3), "=r"(tmp4)
248 			: "ir"(n)
249 			: "lp_count", "memory");
250 		}
251 		if (orig_n / 8) {
252 			orig_n = orig_n % 8;
253 
254 			__asm__ __volatile__(
255 			"14:	ld.ab   %3, [%2,4]		\n"
256 			"15:	ld.ab   %4, [%2,4]		\n"
257 			"	st.ab   %3, [%1,4]		\n"
258 			"	st.ab   %4, [%1,4]		\n"
259 			"	sub     %0,%0,8			\n"
260 			"31:	;nop				\n"
261 			"	.section .fixup, \"ax\"		\n"
262 			"	.align 4			\n"
263 			"4:	j   31b				\n"
264 			"	.previous			\n"
265 			"	.section __ex_table, \"a\"	\n"
266 			"	.align 4			\n"
267 			"	.word   14b,4b			\n"
268 			"	.word   15b,4b			\n"
269 			"	.previous			\n"
270 			: "+r" (res), "+r"(to), "+r"(from),
271 			  "=r"(tmp1), "=r"(tmp2)
272 			:
273 			: "memory");
274 		}
275 		if (orig_n / 4) {
276 			orig_n = orig_n % 4;
277 
278 			__asm__ __volatile__(
279 			"16:	ld.ab   %3, [%2,4]		\n"
280 			"	st.ab   %3, [%1,4]		\n"
281 			"	sub     %0,%0,4			\n"
282 			"32:	;nop				\n"
283 			"	.section .fixup, \"ax\"		\n"
284 			"	.align 4			\n"
285 			"4:	j   32b				\n"
286 			"	.previous			\n"
287 			"	.section __ex_table, \"a\"	\n"
288 			"	.align 4			\n"
289 			"	.word   16b,4b			\n"
290 			"	.previous			\n"
291 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
292 			:
293 			: "memory");
294 		}
295 		if (orig_n / 2) {
296 			orig_n = orig_n % 2;
297 
298 			__asm__ __volatile__(
299 			"17:	ldw.ab   %3, [%2,2]		\n"
300 			"	stw.ab   %3, [%1,2]		\n"
301 			"	sub      %0,%0,2		\n"
302 			"33:	;nop				\n"
303 			"	.section .fixup, \"ax\"		\n"
304 			"	.align 4			\n"
305 			"4:	j   33b				\n"
306 			"	.previous			\n"
307 			"	.section __ex_table, \"a\"	\n"
308 			"	.align 4			\n"
309 			"	.word   17b,4b			\n"
310 			"	.previous			\n"
311 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
312 			:
313 			: "memory");
314 		}
315 		if (orig_n & 1) {
316 			__asm__ __volatile__(
317 			"18:	ldb.ab   %3, [%2,2]		\n"
318 			"	stb.ab   %3, [%1,2]		\n"
319 			"	sub      %0,%0,1		\n"
320 			"34:	; nop				\n"
321 			"	.section .fixup, \"ax\"		\n"
322 			"	.align 4			\n"
323 			"4:	j   34b				\n"
324 			"	.previous			\n"
325 			"	.section __ex_table, \"a\"	\n"
326 			"	.align 4			\n"
327 			"	.word   18b,4b			\n"
328 			"	.previous			\n"
329 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
330 			:
331 			: "memory");
332 		}
333 	} else {  /* n is NOT constant, so laddered copy of 16x,8,4,2,1  */
334 
335 		__asm__ __volatile__(
336 		"	mov %0,%3			\n"
337 		"	lsr.f   lp_count, %3,4		\n"  /* 16x bytes */
338 		"	lpnz    3f			\n"
339 		"1:	ld.ab   %5, [%2, 4]		\n"
340 		"11:	ld.ab   %6, [%2, 4]		\n"
341 		"12:	ld.ab   %7, [%2, 4]		\n"
342 		"13:	ld.ab   %8, [%2, 4]		\n"
343 		"	st.ab   %5, [%1, 4]		\n"
344 		"	st.ab   %6, [%1, 4]		\n"
345 		"	st.ab   %7, [%1, 4]		\n"
346 		"	st.ab   %8, [%1, 4]		\n"
347 		"	sub     %0,%0,16		\n"
348 		"3:	and.f   %3,%3,0xf		\n"  /* stragglers */
349 		"	bz      34f			\n"
350 		"	bbit0   %3,3,31f		\n"  /* 8 bytes left */
351 		"14:	ld.ab   %5, [%2,4]		\n"
352 		"15:	ld.ab   %6, [%2,4]		\n"
353 		"	st.ab   %5, [%1,4]		\n"
354 		"	st.ab   %6, [%1,4]		\n"
355 		"	sub.f   %0,%0,8			\n"
356 		"31:	bbit0   %3,2,32f		\n"  /* 4 bytes left */
357 		"16:	ld.ab   %5, [%2,4]		\n"
358 		"	st.ab   %5, [%1,4]		\n"
359 		"	sub.f   %0,%0,4			\n"
360 		"32:	bbit0   %3,1,33f		\n"  /* 2 bytes left */
361 		"17:	ldw.ab  %5, [%2,2]		\n"
362 		"	stw.ab  %5, [%1,2]		\n"
363 		"	sub.f   %0,%0,2			\n"
364 		"33:	bbit0   %3,0,34f		\n"
365 		"18:	ldb.ab  %5, [%2,1]		\n"  /* 1 byte left */
366 		"	stb.ab  %5, [%1,1]		\n"
367 		"	sub.f   %0,%0,1			\n"
368 		"34:	;nop				\n"
369 		"	.section .fixup, \"ax\"		\n"
370 		"	.align 4			\n"
371 		"4:	j   34b				\n"
372 		"	.previous			\n"
373 		"	.section __ex_table, \"a\"	\n"
374 		"	.align 4			\n"
375 		"	.word   1b, 4b			\n"
376 		"	.word   11b,4b			\n"
377 		"	.word   12b,4b			\n"
378 		"	.word   13b,4b			\n"
379 		"	.word   14b,4b			\n"
380 		"	.word   15b,4b			\n"
381 		"	.word   16b,4b			\n"
382 		"	.word   17b,4b			\n"
383 		"	.word   18b,4b			\n"
384 		"	.previous			\n"
385 		: "=r" (res), "+r"(to), "+r"(from), "+r"(n), "=r"(val),
386 		  "=r"(tmp1), "=r"(tmp2), "=r"(tmp3), "=r"(tmp4)
387 		:
388 		: "lp_count", "memory");
389 	}
390 
391 	return res;
392 }
393 
394 static inline unsigned long
395 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
396 {
397 	long res = 0;
398 	char val;
399 	unsigned long tmp1, tmp2, tmp3, tmp4;
400 	unsigned long orig_n = n;
401 
402 	if (n == 0)
403 		return 0;
404 
405 	/* unaligned */
406 	if (((unsigned long)to & 0x3) || ((unsigned long)from & 0x3)) {
407 
408 		unsigned char tmp;
409 
410 		__asm__ __volatile__(
411 		"	mov.f   lp_count, %0		\n"
412 		"	lpnz 3f				\n"
413 		"	ldb.ab  %1, [%3, 1]		\n"
414 		"1:	stb.ab  %1, [%2, 1]		\n"
415 		"	sub     %0, %0, 1		\n"
416 		"3:	;nop				\n"
417 		"	.section .fixup, \"ax\"		\n"
418 		"	.align 4			\n"
419 		"4:	j   3b				\n"
420 		"	.previous			\n"
421 		"	.section __ex_table, \"a\"	\n"
422 		"	.align 4			\n"
423 		"	.word   1b, 4b			\n"
424 		"	.previous			\n"
425 
426 		: "+r" (n),
427 		/* Note as an '&' earlyclobber operand to make sure the
428 		 * temporary register inside the loop is not the same as
429 		 * FROM or TO.
430 		 */
431 		  "=&r" (tmp), "+r" (to), "+r" (from)
432 		:
433 		: "lp_count", "memory");
434 
435 		return n;
436 	}
437 
438 	if (__builtin_constant_p(orig_n)) {
439 		res = orig_n;
440 
441 		if (orig_n / 16) {
442 			orig_n = orig_n % 16;
443 
444 			__asm__ __volatile__(
445 			"	lsr lp_count, %7,4		\n"
446 			"	lp  3f				\n"
447 			"	ld.ab %3, [%2, 4]		\n"
448 			"	ld.ab %4, [%2, 4]		\n"
449 			"	ld.ab %5, [%2, 4]		\n"
450 			"	ld.ab %6, [%2, 4]		\n"
451 			"1:	st.ab %3, [%1, 4]		\n"
452 			"11:	st.ab %4, [%1, 4]		\n"
453 			"12:	st.ab %5, [%1, 4]		\n"
454 			"13:	st.ab %6, [%1, 4]		\n"
455 			"	sub   %0, %0, 16		\n"
456 			"3:;nop					\n"
457 			"	.section .fixup, \"ax\"		\n"
458 			"	.align 4			\n"
459 			"4:	j   3b				\n"
460 			"	.previous			\n"
461 			"	.section __ex_table, \"a\"	\n"
462 			"	.align 4			\n"
463 			"	.word   1b, 4b			\n"
464 			"	.word   11b,4b			\n"
465 			"	.word   12b,4b			\n"
466 			"	.word   13b,4b			\n"
467 			"	.previous			\n"
468 			: "+r" (res), "+r"(to), "+r"(from),
469 			  "=r"(tmp1), "=r"(tmp2), "=r"(tmp3), "=r"(tmp4)
470 			: "ir"(n)
471 			: "lp_count", "memory");
472 		}
473 		if (orig_n / 8) {
474 			orig_n = orig_n % 8;
475 
476 			__asm__ __volatile__(
477 			"	ld.ab   %3, [%2,4]		\n"
478 			"	ld.ab   %4, [%2,4]		\n"
479 			"14:	st.ab   %3, [%1,4]		\n"
480 			"15:	st.ab   %4, [%1,4]		\n"
481 			"	sub     %0, %0, 8		\n"
482 			"31:;nop				\n"
483 			"	.section .fixup, \"ax\"		\n"
484 			"	.align 4			\n"
485 			"4:	j   31b				\n"
486 			"	.previous			\n"
487 			"	.section __ex_table, \"a\"	\n"
488 			"	.align 4			\n"
489 			"	.word   14b,4b			\n"
490 			"	.word   15b,4b			\n"
491 			"	.previous			\n"
492 			: "+r" (res), "+r"(to), "+r"(from),
493 			  "=r"(tmp1), "=r"(tmp2)
494 			:
495 			: "memory");
496 		}
497 		if (orig_n / 4) {
498 			orig_n = orig_n % 4;
499 
500 			__asm__ __volatile__(
501 			"	ld.ab   %3, [%2,4]		\n"
502 			"16:	st.ab   %3, [%1,4]		\n"
503 			"	sub     %0, %0, 4		\n"
504 			"32:;nop				\n"
505 			"	.section .fixup, \"ax\"		\n"
506 			"	.align 4			\n"
507 			"4:	j   32b				\n"
508 			"	.previous			\n"
509 			"	.section __ex_table, \"a\"	\n"
510 			"	.align 4			\n"
511 			"	.word   16b,4b			\n"
512 			"	.previous			\n"
513 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
514 			:
515 			: "memory");
516 		}
517 		if (orig_n / 2) {
518 			orig_n = orig_n % 2;
519 
520 			__asm__ __volatile__(
521 			"	ldw.ab    %3, [%2,2]		\n"
522 			"17:	stw.ab    %3, [%1,2]		\n"
523 			"	sub       %0, %0, 2		\n"
524 			"33:;nop				\n"
525 			"	.section .fixup, \"ax\"		\n"
526 			"	.align 4			\n"
527 			"4:	j   33b				\n"
528 			"	.previous			\n"
529 			"	.section __ex_table, \"a\"	\n"
530 			"	.align 4			\n"
531 			"	.word   17b,4b			\n"
532 			"	.previous			\n"
533 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
534 			:
535 			: "memory");
536 		}
537 		if (orig_n & 1) {
538 			__asm__ __volatile__(
539 			"	ldb.ab  %3, [%2,1]		\n"
540 			"18:	stb.ab  %3, [%1,1]		\n"
541 			"	sub     %0, %0, 1		\n"
542 			"34:	;nop				\n"
543 			"	.section .fixup, \"ax\"		\n"
544 			"	.align 4			\n"
545 			"4:	j   34b				\n"
546 			"	.previous			\n"
547 			"	.section __ex_table, \"a\"	\n"
548 			"	.align 4			\n"
549 			"	.word   18b,4b			\n"
550 			"	.previous			\n"
551 			: "+r" (res), "+r"(to), "+r"(from), "=r"(tmp1)
552 			:
553 			: "memory");
554 		}
555 	} else {  /* n is NOT constant, so laddered copy of 16x,8,4,2,1  */
556 
557 		__asm__ __volatile__(
558 		"	mov   %0,%3			\n"
559 		"	lsr.f lp_count, %3,4		\n"  /* 16x bytes */
560 		"	lpnz  3f			\n"
561 		"	ld.ab %5, [%2, 4]		\n"
562 		"	ld.ab %6, [%2, 4]		\n"
563 		"	ld.ab %7, [%2, 4]		\n"
564 		"	ld.ab %8, [%2, 4]		\n"
565 		"1:	st.ab %5, [%1, 4]		\n"
566 		"11:	st.ab %6, [%1, 4]		\n"
567 		"12:	st.ab %7, [%1, 4]		\n"
568 		"13:	st.ab %8, [%1, 4]		\n"
569 		"	sub   %0, %0, 16		\n"
570 		"3:	and.f %3,%3,0xf			\n" /* stragglers */
571 		"	bz 34f				\n"
572 		"	bbit0   %3,3,31f		\n" /* 8 bytes left */
573 		"	ld.ab   %5, [%2,4]		\n"
574 		"	ld.ab   %6, [%2,4]		\n"
575 		"14:	st.ab   %5, [%1,4]		\n"
576 		"15:	st.ab   %6, [%1,4]		\n"
577 		"	sub.f   %0, %0, 8		\n"
578 		"31:	bbit0   %3,2,32f		\n"  /* 4 bytes left */
579 		"	ld.ab   %5, [%2,4]		\n"
580 		"16:	st.ab   %5, [%1,4]		\n"
581 		"	sub.f   %0, %0, 4		\n"
582 		"32:	bbit0 %3,1,33f			\n"  /* 2 bytes left */
583 		"	ldw.ab    %5, [%2,2]		\n"
584 		"17:	stw.ab    %5, [%1,2]		\n"
585 		"	sub.f %0, %0, 2			\n"
586 		"33:	bbit0 %3,0,34f			\n"
587 		"	ldb.ab    %5, [%2,1]		\n"  /* 1 byte left */
588 		"18:	stb.ab  %5, [%1,1]		\n"
589 		"	sub.f %0, %0, 1			\n"
590 		"34:	;nop				\n"
591 		"	.section .fixup, \"ax\"		\n"
592 		"	.align 4			\n"
593 		"4:	j   34b				\n"
594 		"	.previous			\n"
595 		"	.section __ex_table, \"a\"	\n"
596 		"	.align 4			\n"
597 		"	.word   1b, 4b			\n"
598 		"	.word   11b,4b			\n"
599 		"	.word   12b,4b			\n"
600 		"	.word   13b,4b			\n"
601 		"	.word   14b,4b			\n"
602 		"	.word   15b,4b			\n"
603 		"	.word   16b,4b			\n"
604 		"	.word   17b,4b			\n"
605 		"	.word   18b,4b			\n"
606 		"	.previous			\n"
607 		: "=r" (res), "+r"(to), "+r"(from), "+r"(n), "=r"(val),
608 		  "=r"(tmp1), "=r"(tmp2), "=r"(tmp3), "=r"(tmp4)
609 		:
610 		: "lp_count", "memory");
611 	}
612 
613 	return res;
614 }
615 
616 static inline unsigned long __arc_clear_user(void __user *to, unsigned long n)
617 {
618 	long res = n;
619 	unsigned char *d_char = to;
620 
621 	__asm__ __volatile__(
622 	"	bbit0   %0, 0, 1f		\n"
623 	"75:	stb.ab  %2, [%0,1]		\n"
624 	"	sub %1, %1, 1			\n"
625 	"1:	bbit0   %0, 1, 2f		\n"
626 	"76:	stw.ab  %2, [%0,2]		\n"
627 	"	sub %1, %1, 2			\n"
628 	"2:	asr.f   lp_count, %1, 2		\n"
629 	"	lpnz    3f			\n"
630 	"77:	st.ab   %2, [%0,4]		\n"
631 	"	sub %1, %1, 4			\n"
632 	"3:	bbit0   %1, 1, 4f		\n"
633 	"78:	stw.ab  %2, [%0,2]		\n"
634 	"	sub %1, %1, 2			\n"
635 	"4:	bbit0   %1, 0, 5f		\n"
636 	"79:	stb.ab  %2, [%0,1]		\n"
637 	"	sub %1, %1, 1			\n"
638 	"5:					\n"
639 	"	.section .fixup, \"ax\"		\n"
640 	"	.align 4			\n"
641 	"3:	j   5b				\n"
642 	"	.previous			\n"
643 	"	.section __ex_table, \"a\"	\n"
644 	"	.align 4			\n"
645 	"	.word   75b, 3b			\n"
646 	"	.word   76b, 3b			\n"
647 	"	.word   77b, 3b			\n"
648 	"	.word   78b, 3b			\n"
649 	"	.word   79b, 3b			\n"
650 	"	.previous			\n"
651 	: "+r"(d_char), "+r"(res)
652 	: "i"(0)
653 	: "lp_count", "memory");
654 
655 	return res;
656 }
657 
658 #ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
659 
660 #define INLINE_COPY_TO_USER
661 #define INLINE_COPY_FROM_USER
662 
663 #define __clear_user(d, n)		__arc_clear_user(d, n)
664 #else
665 extern unsigned long arc_clear_user_noinline(void __user *to,
666 		unsigned long n);
667 #define __clear_user(d, n)		arc_clear_user_noinline(d, n)
668 #endif
669 
670 #include <asm/segment.h>
671 #include <asm-generic/uaccess.h>
672 
673 #endif
674