2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
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.
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
15 #include <linux/linkage.h>
16 #include <asm/errno.h>
17 #include <asm/cache.h>
18 #include <arch/chip.h>
20 /* Access user memory, but use MMU to avoid propagating kernel exceptions. */
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.
27 STD_ENTRY(strnlen_user_asm)
28 { bz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
29 1: { lb_u r4, r0; addi r1, r1, -1 }
31 { bnzt r1, 1b; addi r0, r0, 1 }
32 2: { sub r0, r0, r3; jrp lr }
33 STD_ENDPROC(strnlen_user_asm)
34 .pushsection .fixup,"ax"
36 { move r0, zero; jrp lr }
37 ENDPROC(strnlen_user_fault)
38 .section __ex_table,"a"
40 .word 1b, strnlen_user_fault
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.
49 STD_ENTRY(strncpy_from_user_asm)
50 { bz r2, 2f; move r3, r0 }
51 1: { lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
52 { sb r0, r4; addi r0, r0, 1 }
55 addi r0, r0, -1 /* don't count the trailing NUL */
56 2: { sub r0, r0, r3; jrp lr }
57 STD_ENDPROC(strncpy_from_user_asm)
58 .pushsection .fixup,"ax"
59 strncpy_from_user_fault:
60 { movei r0, -EFAULT; jrp lr }
61 ENDPROC(strncpy_from_user_fault)
62 .section __ex_table,"a"
64 .word 1b, strncpy_from_user_fault
68 * clear_user_asm takes the user target address in r0 and the
69 * number of bytes to zero in r1.
70 * It returns the number of uncopiable bytes (hopefully zero) in r0.
71 * Note that we don't use a separate .fixup section here since we fall
72 * through into the "fixup" code as the last straight-line bundle anyway.
74 STD_ENTRY(clear_user_asm)
75 { bz r1, 2f; or r2, r0, r1 }
77 bzt r2, .Lclear_aligned_user_asm
78 1: { sb r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
80 2: { move r0, r1; jrp lr }
81 .pushsection __ex_table,"a"
86 .Lclear_aligned_user_asm:
87 1: { sw r0, zero; addi r0, r0, 4; addi r1, r1, -4 }
89 2: { move r0, r1; jrp lr }
90 STD_ENDPROC(clear_user_asm)
91 .pushsection __ex_table,"a"
97 * flush_user_asm takes the user target address in r0 and the
98 * number of bytes to flush in r1.
99 * It returns the number of unflushable bytes (hopefully zero) in r0.
101 STD_ENTRY(flush_user_asm)
103 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
104 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
105 { and r0, r0, r2; and r1, r1, r2 }
107 1: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
108 { addi r0, r0, CHIP_FLUSH_STRIDE(); bnzt r1, 1b }
109 2: { move r0, r1; jrp lr }
110 STD_ENDPROC(flush_user_asm)
111 .pushsection __ex_table,"a"
117 * finv_user_asm takes the user target address in r0 and the
118 * number of bytes to flush-invalidate in r1.
119 * It returns the number of not finv'able bytes (hopefully zero) in r0.
121 STD_ENTRY(finv_user_asm)
123 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
124 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
125 { and r0, r0, r2; and r1, r1, r2 }
127 1: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
128 { addi r0, r0, CHIP_FINV_STRIDE(); bnzt r1, 1b }
129 2: { move r0, r1; jrp lr }
130 STD_ENDPROC(finv_user_asm)
131 .pushsection __ex_table,"a"