diff options
Diffstat (limited to 'arch/sparc/lib/copy_in_user.S')
| -rw-r--r-- | arch/sparc/lib/copy_in_user.S | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/sparc/lib/copy_in_user.S b/arch/sparc/lib/copy_in_user.S new file mode 100644 index 000000000000..650af3f21f78 --- /dev/null +++ b/arch/sparc/lib/copy_in_user.S @@ -0,0 +1,119 @@ +/* copy_in_user.S: Copy from userspace to userspace. + * + * Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com) + */ + +#include <asm/asi.h> + +#define XCC xcc + +#define EX(x,y) \ +98: x,y; \ + .section .fixup; \ + .align 4; \ +99: retl; \ + mov 1, %o0; \ + .section __ex_table,"a";\ + .align 4; \ + .word 98b, 99b; \ + .text; \ + .align 4; + + .register %g2,#scratch + .register %g3,#scratch + + .text + .align 32 + + /* Don't try to get too fancy here, just nice and + * simple. This is predominantly used for well aligned + * small copies in the compat layer. It is also used + * to copy register windows around during thread cloning. + */ + + .globl ___copy_in_user + .type ___copy_in_user,#function +___copy_in_user: /* %o0=dst, %o1=src, %o2=len */ + /* Writing to %asi is _expensive_ so we hardcode it. + * Reading %asi to check for KERNEL_DS is comparatively + * cheap. + */ + rd %asi, %g1 + cmp %g1, ASI_AIUS + bne,pn %icc, memcpy_user_stub + nop + + cmp %o2, 0 + be,pn %XCC, 85f + or %o0, %o1, %o3 + cmp %o2, 16 + bleu,a,pn %XCC, 80f + or %o3, %o2, %o3 + + /* 16 < len <= 64 */ + andcc %o3, 0x7, %g0 + bne,pn %XCC, 90f + sub %o0, %o1, %o3 + + andn %o2, 0x7, %o4 + and %o2, 0x7, %o2 +1: subcc %o4, 0x8, %o4 + EX(ldxa [%o1] %asi, %o5) + EX(stxa %o5, [%o1 + %o3] ASI_AIUS) + bgu,pt %XCC, 1b + add %o1, 0x8, %o1 + andcc %o2, 0x4, %g0 + be,pt %XCC, 1f + nop + sub %o2, 0x4, %o2 + EX(lduwa [%o1] %asi, %o5) + EX(stwa %o5, [%o1 + %o3] ASI_AIUS) + add %o1, 0x4, %o1 +1: cmp %o2, 0 + be,pt %XCC, 85f + nop + ba,pt %xcc, 90f + nop + +80: /* 0 < len <= 16 */ + andcc %o3, 0x3, %g0 + bne,pn %XCC, 90f + sub %o0, %o1, %o3 + +82: + subcc %o2, 4, %o2 + EX(lduwa [%o1] %asi, %g1) + EX(stwa %g1, [%o1 + %o3] ASI_AIUS) + bgu,pt %XCC, 82b + add %o1, 4, %o1 + +85: retl + clr %o0 + + .align 32 +90: + subcc %o2, 1, %o2 + EX(lduba [%o1] %asi, %g1) + EX(stba %g1, [%o1 + %o3] ASI_AIUS) + bgu,pt %XCC, 90b + add %o1, 1, %o1 + retl + clr %o0 + + .size ___copy_in_user, .-___copy_in_user + + /* Act like copy_{to,in}_user(), ie. return zero instead + * of original destination pointer. This is invoked when + * copy_{to,in}_user() finds that %asi is kernel space. + */ + .globl memcpy_user_stub + .type memcpy_user_stub,#function +memcpy_user_stub: + save %sp, -192, %sp + mov %i0, %o0 + mov %i1, %o1 + call memcpy + mov %i2, %o2 + ret + restore %g0, %g0, %o0 + .size memcpy_user_stub, .-memcpy_user_stub |