diff options
Diffstat (limited to 'arch/sh/lib/__clear_user.S')
| -rw-r--r-- | arch/sh/lib/__clear_user.S | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/sh/lib/__clear_user.S b/arch/sh/lib/__clear_user.S new file mode 100644 index 00000000000..db1dca7aad1 --- /dev/null +++ b/arch/sh/lib/__clear_user.S @@ -0,0 +1,108 @@ +/* + * __clear_user_page, __clear_user, clear_page implementation of SuperH + * + * Copyright (C) 2001 Kaz Kojima + * Copyright (C) 2001, 2002 Niibe Yutaka + * Copyright (C) 2006 Paul Mundt + */ +#include <linux/linkage.h> +#include <asm/page.h> + +ENTRY(__clear_user) + ! + mov #0, r0 + mov #0xffffffe0, r1 + ! + ! r4..(r4+31)&~32 -------- not aligned [ Area 0 ] + ! (r4+31)&~32..(r4+r5)&~32 -------- aligned [ Area 1 ] + ! (r4+r5)&~32..r4+r5 -------- not aligned [ Area 2 ] + ! + ! Clear area 0 + mov r4, r2 + ! + tst r1, r5 ! length < 32 + bt .Larea2 ! skip to remainder + ! + add #31, r2 + and r1, r2 + cmp/eq r4, r2 + bt .Larea1 + mov r2, r3 + sub r4, r3 + mov r3, r7 + mov r4, r2 + ! +.L0: dt r3 +0: mov.b r0, @r2 + bf/s .L0 + add #1, r2 + ! + sub r7, r5 + mov r2, r4 +.Larea1: + mov r4, r3 + add r5, r3 + and r1, r3 + cmp/hi r2, r3 + bf .Larea2 + ! + ! Clear area 1 +#if defined(CONFIG_CPU_SH4) +1: movca.l r0, @r2 +#else +1: mov.l r0, @r2 +#endif + add #4, r2 +2: mov.l r0, @r2 + add #4, r2 +3: mov.l r0, @r2 + add #4, r2 +4: mov.l r0, @r2 + add #4, r2 +5: mov.l r0, @r2 + add #4, r2 +6: mov.l r0, @r2 + add #4, r2 +7: mov.l r0, @r2 + add #4, r2 +8: mov.l r0, @r2 + add #4, r2 + cmp/hi r2, r3 + bt/s 1b + nop + ! + ! Clear area 2 +.Larea2: + mov r4, r3 + add r5, r3 + cmp/hs r3, r2 + bt/s .Ldone + sub r2, r3 +.L2: dt r3 +9: mov.b r0, @r2 + bf/s .L2 + add #1, r2 + ! +.Ldone: rts + mov #0, r0 ! return 0 as normal return + + ! return the number of bytes remained +.Lbad_clear_user: + mov r4, r0 + add r5, r0 + rts + sub r2, r0 + +.section __ex_table,"a" + .align 2 + .long 0b, .Lbad_clear_user + .long 1b, .Lbad_clear_user + .long 2b, .Lbad_clear_user + .long 3b, .Lbad_clear_user + .long 4b, .Lbad_clear_user + .long 5b, .Lbad_clear_user + .long 6b, .Lbad_clear_user + .long 7b, .Lbad_clear_user + .long 8b, .Lbad_clear_user + .long 9b, .Lbad_clear_user +.previous |