projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 77c93b2f G |
1 | /* |
| 2 | * linux/arch/unicore32/lib/clear_user.S | |
| 3 | * | |
| 4 | * Code specific to PKUnity SoC and UniCore ISA | |
| 5 | * | |
| 6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | #include <linux/linkage.h> | |
| 13 | #include <asm/assembler.h> | |
| 14 | ||
| 15 | .text | |
| 16 | ||
| 17 | /* Prototype: int __clear_user(void *addr, size_t sz) | |
| 18 | * Purpose : clear some user memory | |
| 19 | * Params : addr - user memory address to clear | |
| 20 | * : sz - number of bytes to clear | |
| 21 | * Returns : number of bytes NOT cleared | |
| 22 | */ | |
| 23 | WEAK(__clear_user) | |
| 24 | stm.w (lr), [sp-] | |
| 25 | stm.w (r1), [sp-] | |
| 26 | mov r2, #0 | |
| 27 | csub.a r1, #4 | |
| 28 | bsl 2f | |
| 29 | and.a ip, r0, #3 | |
| 30 | beq 1f | |
| 31 | csub.a ip, #2 | |
| 32 | strusr r2, r0, 1 | |
| 33 | strusr r2, r0, 1, el | |
| 34 | strusr r2, r0, 1, sl | |
| 35 | rsub ip, ip, #4 | |
| 36 | sub r1, r1, ip @ 7 6 5 4 3 2 1 | |
| 37 | 1: sub.a r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7 | |
| 38 | strusr r2, r0, 4, ns, rept=2 | |
| 39 | bns 1b | |
| 40 | add.a r1, r1, #4 @ 3 2 1 0 -1 -2 -3 | |
| 41 | strusr r2, r0, 4, ns | |
| 42 | 2: cand.a r1, #2 @ 1x 1x 0x 0x 1x 1x 0x | |
| 43 | strusr r2, r0, 1, ne, rept=2 | |
| 44 | cand.a r1, #1 @ x1 x0 x1 x0 x1 x0 x1 | |
| 45 | beq 3f | |
| 46 | USER( stb.u r2, [r0]) | |
| 47 | 3: mov r0, #0 | |
| 48 | ldm.w (r1), [sp]+ | |
| 49 | ldm.w (pc), [sp]+ | |
| 50 | ENDPROC(__clear_user) | |
| 51 | ||
| 52 | .pushsection .fixup,"ax" | |
| 53 | .align 0 | |
| 54 | 9001: ldm.w (r0), [sp]+ | |
| 55 | ldm.w (pc), [sp]+ | |
| 56 | .popsection | |
| 57 |