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Chris Metcalf18aecc22011-05-04 14:38:26 -04001/*
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
Chris Metcalf18aecc22011-05-04 14:38:26 -040022/*
23 * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
24 * It returns the length, including the terminating NUL, or zero on exception.
25 * If length is greater than the bound, returns one plus the bound.
26 */
27STD_ENTRY(strnlen_user_asm)
28 { beqz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
291: { ld1u r4, r0; addi r1, r1, -1 }
30 beqz r4, 2f
31 { bnezt r1, 1b; addi r0, r0, 1 }
322: { sub r0, r0, r3; jrp lr }
33 STD_ENDPROC(strnlen_user_asm)
34 .pushsection .fixup,"ax"
35strnlen_user_fault:
36 { move r0, zero; jrp lr }
37 ENDPROC(strnlen_user_fault)
38 .section __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -040039 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -040040 .quad 1b, strnlen_user_fault
41 .popsection
42
43/*
44 * strncpy_from_user_asm takes the kernel target pointer in r0,
45 * the userspace source pointer in r1, and the length bound (including
46 * the trailing NUL) in r2. On success, it returns the string length
47 * (not including the trailing NUL), or -EFAULT on failure.
48 */
49STD_ENTRY(strncpy_from_user_asm)
50 { beqz r2, 2f; move r3, r0 }
Chris Metcalfc0f06012013-08-09 16:21:43 -0400511: { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
Chris Metcalf18aecc22011-05-04 14:38:26 -040052 { st1 r0, r4; addi r0, r0, 1 }
Chris Metcalfc0f06012013-08-09 16:21:43 -040053 beqz r4, 2f
54 bnezt r2, 1b
55 { sub r0, r0, r3; jrp lr }
562: addi r0, r0, -1 /* don't count the trailing NUL */
57 { sub r0, r0, r3; jrp lr }
Chris Metcalf18aecc22011-05-04 14:38:26 -040058 STD_ENDPROC(strncpy_from_user_asm)
59 .pushsection .fixup,"ax"
60strncpy_from_user_fault:
61 { movei r0, -EFAULT; jrp lr }
62 ENDPROC(strncpy_from_user_fault)
63 .section __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -040064 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -040065 .quad 1b, strncpy_from_user_fault
66 .popsection
67
68/*
69 * clear_user_asm takes the user target address in r0 and the
70 * number of bytes to zero in r1.
71 * It returns the number of uncopiable bytes (hopefully zero) in r0.
72 * Note that we don't use a separate .fixup section here since we fall
73 * through into the "fixup" code as the last straight-line bundle anyway.
74 */
75STD_ENTRY(clear_user_asm)
76 { beqz r1, 2f; or r2, r0, r1 }
77 andi r2, r2, 7
78 beqzt r2, .Lclear_aligned_user_asm
791: { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
80 bnezt r1, 1b
812: { move r0, r1; jrp lr }
82 .pushsection __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -040083 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -040084 .quad 1b, 2b
85 .popsection
86
87.Lclear_aligned_user_asm:
881: { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 }
89 bnezt r1, 1b
902: { move r0, r1; jrp lr }
91 STD_ENDPROC(clear_user_asm)
92 .pushsection __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -040093 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -040094 .quad 1b, 2b
95 .popsection
96
97/*
98 * flush_user_asm takes the user target address in r0 and the
99 * number of bytes to flush in r1.
100 * It returns the number of unflushable bytes (hopefully zero) in r0.
101 */
102STD_ENTRY(flush_user_asm)
103 beqz r1, 2f
104 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
105 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
106 { and r0, r0, r2; and r1, r1, r2 }
107 { sub r1, r1, r0 }
1081: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
109 { addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b }
1102: { move r0, r1; jrp lr }
111 STD_ENDPROC(flush_user_asm)
112 .pushsection __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -0400113 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -0400114 .quad 1b, 2b
115 .popsection
116
117/*
Chris Metcalf18aecc22011-05-04 14:38:26 -0400118 * finv_user_asm takes the user target address in r0 and the
119 * number of bytes to flush-invalidate in r1.
120 * It returns the number of not finv'able bytes (hopefully zero) in r0.
121 */
122STD_ENTRY(finv_user_asm)
123 beqz r1, 2f
124 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
125 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
126 { and r0, r0, r2; and r1, r1, r2 }
127 { sub r1, r1, r0 }
1281: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
129 { addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b }
1302: { move r0, r1; jrp lr }
131 STD_ENDPROC(finv_user_asm)
132 .pushsection __ex_table,"a"
Chris Metcalfd4d9eab2013-08-09 15:38:43 -0400133 .align 8
Chris Metcalf18aecc22011-05-04 14:38:26 -0400134 .quad 1b, 2b
135 .popsection