diff options
Diffstat (limited to 'arch/unicore32/lib/clear_user.S')
| -rw-r--r-- | arch/unicore32/lib/clear_user.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/unicore32/lib/clear_user.S b/arch/unicore32/lib/clear_user.S new file mode 100644 index 000000000000..20047f7224fd --- /dev/null +++ b/arch/unicore32/lib/clear_user.S @@ -0,0 +1,57 @@ +/* + * linux/arch/unicore32/lib/clear_user.S + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + +/* Prototype: int __clear_user(void *addr, size_t sz) + * Purpose : clear some user memory + * Params : addr - user memory address to clear + * : sz - number of bytes to clear + * Returns : number of bytes NOT cleared + */ +WEAK(__clear_user) + stm.w (lr), [sp-] + stm.w (r1), [sp-] + mov r2, #0 + csub.a r1, #4 + bsl 2f + and.a ip, r0, #3 + beq 1f + csub.a ip, #2 + strusr r2, r0, 1 + strusr r2, r0, 1, el + strusr r2, r0, 1, sl + rsub ip, ip, #4 + sub r1, r1, ip @ 7 6 5 4 3 2 1 +1: sub.a r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7 + strusr r2, r0, 4, ns, rept=2 + bns 1b + add.a r1, r1, #4 @ 3 2 1 0 -1 -2 -3 + strusr r2, r0, 4, ns +2: cand.a r1, #2 @ 1x 1x 0x 0x 1x 1x 0x + strusr r2, r0, 1, ne, rept=2 + cand.a r1, #1 @ x1 x0 x1 x0 x1 x0 x1 + beq 3f +USER( stb.u r2, [r0]) +3: mov r0, #0 + ldm.w (r1), [sp]+ + ldm.w (pc), [sp]+ +ENDPROC(__clear_user) + + .pushsection .fixup,"ax" + .align 0 +9001: ldm.w (r0), [sp]+ + ldm.w (pc), [sp]+ + .popsection + |