| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* copy_in_user.S: Copy from userspace to userspace. |
| 2 | * |
| 3 | * Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com) |
| 4 | */ |
| 5 | |
| 6 | #include <asm/asi.h> |
| 7 | |
| 8 | #define XCC xcc |
| 9 | |
| 10 | #define EX(x,y) \ |
| 11 | 98: x,y; \ |
| 12 | .section .fixup; \ |
| 13 | .align 4; \ |
| 14 | 99: retl; \ |
| 15 | mov 1, %o0; \ |
| David S. Miller | 4d000d5 | 2006-03-04 23:23:56 -0800 | [diff] [blame] | 16 | .section __ex_table,"a";\ |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | .align 4; \ |
| 18 | .word 98b, 99b; \ |
| 19 | .text; \ |
| 20 | .align 4; |
| 21 | |
| 22 | .register %g2,#scratch |
| 23 | .register %g3,#scratch |
| 24 | |
| 25 | .text |
| 26 | .align 32 |
| 27 | |
| 28 | /* Don't try to get too fancy here, just nice and |
| 29 | * simple. This is predominantly used for well aligned |
| 30 | * small copies in the compat layer. It is also used |
| 31 | * to copy register windows around during thread cloning. |
| 32 | */ |
| 33 | |
| 34 | .globl ___copy_in_user |
| 35 | .type ___copy_in_user,#function |
| 36 | ___copy_in_user: /* %o0=dst, %o1=src, %o2=len */ |
| 37 | /* Writing to %asi is _expensive_ so we hardcode it. |
| 38 | * Reading %asi to check for KERNEL_DS is comparatively |
| 39 | * cheap. |
| 40 | */ |
| 41 | rd %asi, %g1 |
| 42 | cmp %g1, ASI_AIUS |
| 43 | bne,pn %icc, memcpy_user_stub |
| 44 | nop |
| 45 | |
| 46 | cmp %o2, 0 |
| 47 | be,pn %XCC, 85f |
| 48 | or %o0, %o1, %o3 |
| 49 | cmp %o2, 16 |
| 50 | bleu,a,pn %XCC, 80f |
| 51 | or %o3, %o2, %o3 |
| 52 | |
| 53 | /* 16 < len <= 64 */ |
| 54 | andcc %o3, 0x7, %g0 |
| 55 | bne,pn %XCC, 90f |
| 56 | sub %o0, %o1, %o3 |
| 57 | |
| 58 | andn %o2, 0x7, %o4 |
| 59 | and %o2, 0x7, %o2 |
| 60 | 1: subcc %o4, 0x8, %o4 |
| 61 | EX(ldxa [%o1] %asi, %o5) |
| 62 | EX(stxa %o5, [%o1 + %o3] ASI_AIUS) |
| 63 | bgu,pt %XCC, 1b |
| 64 | add %o1, 0x8, %o1 |
| 65 | andcc %o2, 0x4, %g0 |
| 66 | be,pt %XCC, 1f |
| 67 | nop |
| 68 | sub %o2, 0x4, %o2 |
| 69 | EX(lduwa [%o1] %asi, %o5) |
| 70 | EX(stwa %o5, [%o1 + %o3] ASI_AIUS) |
| 71 | add %o1, 0x4, %o1 |
| 72 | 1: cmp %o2, 0 |
| 73 | be,pt %XCC, 85f |
| 74 | nop |
| 75 | ba,pt %xcc, 90f |
| 76 | nop |
| 77 | |
| 78 | 80: /* 0 < len <= 16 */ |
| 79 | andcc %o3, 0x3, %g0 |
| 80 | bne,pn %XCC, 90f |
| 81 | sub %o0, %o1, %o3 |
| 82 | |
| 83 | 82: |
| 84 | subcc %o2, 4, %o2 |
| 85 | EX(lduwa [%o1] %asi, %g1) |
| 86 | EX(stwa %g1, [%o1 + %o3] ASI_AIUS) |
| 87 | bgu,pt %XCC, 82b |
| 88 | add %o1, 4, %o1 |
| 89 | |
| 90 | 85: retl |
| 91 | clr %o0 |
| 92 | |
| 93 | .align 32 |
| 94 | 90: |
| 95 | subcc %o2, 1, %o2 |
| 96 | EX(lduba [%o1] %asi, %g1) |
| 97 | EX(stba %g1, [%o1 + %o3] ASI_AIUS) |
| 98 | bgu,pt %XCC, 90b |
| 99 | add %o1, 1, %o1 |
| 100 | retl |
| 101 | clr %o0 |
| 102 | |
| 103 | .size ___copy_in_user, .-___copy_in_user |
| 104 | |
| 105 | /* Act like copy_{to,in}_user(), ie. return zero instead |
| 106 | * of original destination pointer. This is invoked when |
| 107 | * copy_{to,in}_user() finds that %asi is kernel space. |
| 108 | */ |
| 109 | .globl memcpy_user_stub |
| 110 | .type memcpy_user_stub,#function |
| 111 | memcpy_user_stub: |
| 112 | save %sp, -192, %sp |
| 113 | mov %i0, %o0 |
| 114 | mov %i1, %o1 |
| 115 | call memcpy |
| 116 | mov %i2, %o2 |
| 117 | ret |
| 118 | restore %g0, %g0, %o0 |
| 119 | .size memcpy_user_stub, .-memcpy_user_stub |