| Paul Mundt | 510c72ad | 2006-11-27 12:06:26 +0900 | [diff] [blame] | 1 | /* |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * __clear_user_page, __clear_user, clear_page implementation of SuperH |
| 3 | * |
| 4 | * Copyright (C) 2001 Kaz Kojima |
| 5 | * Copyright (C) 2001, 2002 Niibe Yutaka |
| Paul Mundt | 510c72ad | 2006-11-27 12:06:26 +0900 | [diff] [blame] | 6 | * Copyright (C) 2006 Paul Mundt |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | */ |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/linkage.h> |
| Paul Mundt | 510c72ad | 2006-11-27 12:06:26 +0900 | [diff] [blame] | 9 | #include <asm/page.h> |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | ENTRY(__clear_user) |
| 12 | ! |
| 13 | mov #0, r0 |
| Stuart Menefy | fea966f | 2009-08-24 17:09:53 +0900 | [diff] [blame] | 14 | mov #0xffffffe0, r1 |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | ! |
| 16 | ! r4..(r4+31)&~32 -------- not aligned [ Area 0 ] |
| 17 | ! (r4+31)&~32..(r4+r5)&~32 -------- aligned [ Area 1 ] |
| 18 | ! (r4+r5)&~32..r4+r5 -------- not aligned [ Area 2 ] |
| 19 | ! |
| 20 | ! Clear area 0 |
| 21 | mov r4, r2 |
| 22 | ! |
| 23 | tst r1, r5 ! length < 32 |
| 24 | bt .Larea2 ! skip to remainder |
| 25 | ! |
| 26 | add #31, r2 |
| 27 | and r1, r2 |
| 28 | cmp/eq r4, r2 |
| 29 | bt .Larea1 |
| 30 | mov r2, r3 |
| 31 | sub r4, r3 |
| 32 | mov r3, r7 |
| 33 | mov r4, r2 |
| 34 | ! |
| 35 | .L0: dt r3 |
| 36 | 0: mov.b r0, @r2 |
| 37 | bf/s .L0 |
| 38 | add #1, r2 |
| 39 | ! |
| 40 | sub r7, r5 |
| 41 | mov r2, r4 |
| 42 | .Larea1: |
| 43 | mov r4, r3 |
| 44 | add r5, r3 |
| 45 | and r1, r3 |
| 46 | cmp/hi r2, r3 |
| 47 | bf .Larea2 |
| 48 | ! |
| 49 | ! Clear area 1 |
| 50 | #if defined(CONFIG_CPU_SH4) |
| 51 | 1: movca.l r0, @r2 |
| 52 | #else |
| 53 | 1: mov.l r0, @r2 |
| 54 | #endif |
| 55 | add #4, r2 |
| 56 | 2: mov.l r0, @r2 |
| 57 | add #4, r2 |
| 58 | 3: mov.l r0, @r2 |
| 59 | add #4, r2 |
| 60 | 4: mov.l r0, @r2 |
| 61 | add #4, r2 |
| 62 | 5: mov.l r0, @r2 |
| 63 | add #4, r2 |
| 64 | 6: mov.l r0, @r2 |
| 65 | add #4, r2 |
| 66 | 7: mov.l r0, @r2 |
| 67 | add #4, r2 |
| 68 | 8: mov.l r0, @r2 |
| 69 | add #4, r2 |
| 70 | cmp/hi r2, r3 |
| 71 | bt/s 1b |
| 72 | nop |
| 73 | ! |
| 74 | ! Clear area 2 |
| 75 | .Larea2: |
| 76 | mov r4, r3 |
| 77 | add r5, r3 |
| 78 | cmp/hs r3, r2 |
| 79 | bt/s .Ldone |
| 80 | sub r2, r3 |
| 81 | .L2: dt r3 |
| 82 | 9: mov.b r0, @r2 |
| 83 | bf/s .L2 |
| 84 | add #1, r2 |
| 85 | ! |
| 86 | .Ldone: rts |
| 87 | mov #0, r0 ! return 0 as normal return |
| 88 | |
| 89 | ! return the number of bytes remained |
| 90 | .Lbad_clear_user: |
| 91 | mov r4, r0 |
| 92 | add r5, r0 |
| 93 | rts |
| 94 | sub r2, r0 |
| 95 | |
| 96 | .section __ex_table,"a" |
| 97 | .align 2 |
| 98 | .long 0b, .Lbad_clear_user |
| 99 | .long 1b, .Lbad_clear_user |
| 100 | .long 2b, .Lbad_clear_user |
| 101 | .long 3b, .Lbad_clear_user |
| 102 | .long 4b, .Lbad_clear_user |
| 103 | .long 5b, .Lbad_clear_user |
| 104 | .long 6b, .Lbad_clear_user |
| 105 | .long 7b, .Lbad_clear_user |
| 106 | .long 8b, .Lbad_clear_user |
| 107 | .long 9b, .Lbad_clear_user |
| 108 | .previous |