aboutsummaryrefslogtreecommitdiff
path: root/arch/sparc64/lib/copy_in_user.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sparc64/lib/copy_in_user.S')
-rw-r--r--arch/sparc64/lib/copy_in_user.S119
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/sparc64/lib/copy_in_user.S b/arch/sparc64/lib/copy_in_user.S
new file mode 100644
index 00000000000..816076c0bc0
--- /dev/null
+++ b/arch/sparc64/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; \
+ .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