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/arch/tile/lib/usercopy_64.S

https://bitbucket.org/ndreys/linux-sunxi
Assembly | 196 lines | 181 code | 15 blank | 0 comment | 0 complexity | 7fe6975289d08d6ef1d0c8f9bec2d242 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/*
  2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 */
 14
 15#include <linux/linkage.h>
 16#include <asm/errno.h>
 17#include <asm/cache.h>
 18#include <arch/chip.h>
 19
 20/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
 21
 22	.pushsection .fixup,"ax"
 23
 24get_user_fault:
 25	{ movei r1, -EFAULT; move r0, zero }
 26	jrp lr
 27	ENDPROC(get_user_fault)
 28
 29put_user_fault:
 30	{ movei r0, -EFAULT; jrp lr }
 31	ENDPROC(put_user_fault)
 32
 33	.popsection
 34
 35/*
 36 * __get_user_N functions take a pointer in r0, and return 0 in r1
 37 * on success, with the value in r0; or else -EFAULT in r1.
 38 */
 39#define __get_user_N(bytes, LOAD) \
 40	STD_ENTRY(__get_user_##bytes); \
 411:	{ LOAD r0, r0; move r1, zero }; \
 42	jrp lr; \
 43	STD_ENDPROC(__get_user_##bytes); \
 44	.pushsection __ex_table,"a"; \
 45	.quad 1b, get_user_fault; \
 46	.popsection
 47
 48__get_user_N(1, ld1u)
 49__get_user_N(2, ld2u)
 50__get_user_N(4, ld4u)
 51__get_user_N(8, ld)
 52
 53/*
 54 * __put_user_N functions take a value in r0 and a pointer in r1,
 55 * and return 0 in r0 on success or -EFAULT on failure.
 56 */
 57#define __put_user_N(bytes, STORE) \
 58	STD_ENTRY(__put_user_##bytes); \
 591:	{ STORE r1, r0; move r0, zero }; \
 60	jrp lr; \
 61	STD_ENDPROC(__put_user_##bytes); \
 62	.pushsection __ex_table,"a"; \
 63	.quad 1b, put_user_fault; \
 64	.popsection
 65
 66__put_user_N(1, st1)
 67__put_user_N(2, st2)
 68__put_user_N(4, st4)
 69__put_user_N(8, st)
 70
 71/*
 72 * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
 73 * It returns the length, including the terminating NUL, or zero on exception.
 74 * If length is greater than the bound, returns one plus the bound.
 75 */
 76STD_ENTRY(strnlen_user_asm)
 77	{ beqz r1, 2f; addi r3, r0, -1 }  /* bias down to include NUL */
 781:      { ld1u r4, r0; addi r1, r1, -1 }
 79	beqz r4, 2f
 80	{ bnezt r1, 1b; addi r0, r0, 1 }
 812:      { sub r0, r0, r3; jrp lr }
 82	STD_ENDPROC(strnlen_user_asm)
 83	.pushsection .fixup,"ax"
 84strnlen_user_fault:
 85	{ move r0, zero; jrp lr }
 86	ENDPROC(strnlen_user_fault)
 87	.section __ex_table,"a"
 88	.quad 1b, strnlen_user_fault
 89	.popsection
 90
 91/*
 92 * strncpy_from_user_asm takes the kernel target pointer in r0,
 93 * the userspace source pointer in r1, and the length bound (including
 94 * the trailing NUL) in r2.  On success, it returns the string length
 95 * (not including the trailing NUL), or -EFAULT on failure.
 96 */
 97STD_ENTRY(strncpy_from_user_asm)
 98	{ beqz r2, 2f; move r3, r0 }
 991:      { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
100	{ st1 r0, r4; addi r0, r0, 1 }
101	beqz r2, 2f
102	bnezt r4, 1b
103	addi r0, r0, -1   /* don't count the trailing NUL */
1042:      { sub r0, r0, r3; jrp lr }
105	STD_ENDPROC(strncpy_from_user_asm)
106	.pushsection .fixup,"ax"
107strncpy_from_user_fault:
108	{ movei r0, -EFAULT; jrp lr }
109	ENDPROC(strncpy_from_user_fault)
110	.section __ex_table,"a"
111	.quad 1b, strncpy_from_user_fault
112	.popsection
113
114/*
115 * clear_user_asm takes the user target address in r0 and the
116 * number of bytes to zero in r1.
117 * It returns the number of uncopiable bytes (hopefully zero) in r0.
118 * Note that we don't use a separate .fixup section here since we fall
119 * through into the "fixup" code as the last straight-line bundle anyway.
120 */
121STD_ENTRY(clear_user_asm)
122	{ beqz r1, 2f; or r2, r0, r1 }
123	andi r2, r2, 7
124	beqzt r2, .Lclear_aligned_user_asm
1251:      { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
126	bnezt r1, 1b
1272:      { move r0, r1; jrp lr }
128	.pushsection __ex_table,"a"
129	.quad 1b, 2b
130	.popsection
131
132.Lclear_aligned_user_asm:
1331:      { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 }
134	bnezt r1, 1b
1352:      { move r0, r1; jrp lr }
136	STD_ENDPROC(clear_user_asm)
137	.pushsection __ex_table,"a"
138	.quad 1b, 2b
139	.popsection
140
141/*
142 * flush_user_asm takes the user target address in r0 and the
143 * number of bytes to flush in r1.
144 * It returns the number of unflushable bytes (hopefully zero) in r0.
145 */
146STD_ENTRY(flush_user_asm)
147	beqz r1, 2f
148	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
149	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
150	{ and r0, r0, r2; and r1, r1, r2 }
151	{ sub r1, r1, r0 }
1521:      { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
153	{ addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b }
1542:      { move r0, r1; jrp lr }
155	STD_ENDPROC(flush_user_asm)
156	.pushsection __ex_table,"a"
157	.quad 1b, 2b
158	.popsection
159
160/*
161 * inv_user_asm takes the user target address in r0 and the
162 * number of bytes to invalidate in r1.
163 * It returns the number of not inv'able bytes (hopefully zero) in r0.
164 */
165STD_ENTRY(inv_user_asm)
166	beqz r1, 2f
167	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
168	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
169	{ and r0, r0, r2; and r1, r1, r2 }
170	{ sub r1, r1, r0 }
1711:      { inv r0; addi r1, r1, -CHIP_INV_STRIDE() }
172	{ addi r0, r0, CHIP_INV_STRIDE(); bnezt r1, 1b }
1732:      { move r0, r1; jrp lr }
174	STD_ENDPROC(inv_user_asm)
175	.pushsection __ex_table,"a"
176	.quad 1b, 2b
177	.popsection
178
179/*
180 * finv_user_asm takes the user target address in r0 and the
181 * number of bytes to flush-invalidate in r1.
182 * It returns the number of not finv'able bytes (hopefully zero) in r0.
183 */
184STD_ENTRY(finv_user_asm)
185	beqz r1, 2f
186	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
187	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
188	{ and r0, r0, r2; and r1, r1, r2 }
189	{ sub r1, r1, r0 }
1901:      { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
191	{ addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b }
1922:      { move r0, r1; jrp lr }
193	STD_ENDPROC(finv_user_asm)
194	.pushsection __ex_table,"a"
195	.quad 1b, 2b
196	.popsection