This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / arm / lib / clear_user.S

diff --git a/arch/arm/lib/clear_user.S b/arch/arm/lib/clear_user.S
new file mode 100644 (file)
index 0000000..7ff9f83
--- /dev/null
+++ b/arch/arm/lib/clear_user.S
@@ -0,0 +1,52 @@
+/*
+ *  linux/arch/arm/lib/clear_user.S
+ *
+ *  Copyright (C) 1995, 1996,1997,1998 Russell King
+ *
+ * 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 __arch_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
+ */
+ENTRY(__arch_clear_user)
+               stmfd   sp!, {r1, lr}
+               mov     r2, #0
+               cmp     r1, #4
+               blt     2f
+               ands    ip, r0, #3
+               beq     1f
+               cmp     ip, #2
+USER(          strbt   r2, [r0], #1)
+USER(          strlebt r2, [r0], #1)
+USER(          strltbt r2, [r0], #1)
+               rsb     ip, ip, #4
+               sub     r1, r1, ip              @  7  6  5  4  3  2  1
+1:             subs    r1, r1, #8              @ -1 -2 -3 -4 -5 -6 -7
+USER(          strplt  r2, [r0], #4)
+USER(          strplt  r2, [r0], #4)
+               bpl     1b
+               adds    r1, r1, #4              @  3  2  1  0 -1 -2 -3
+USER(          strplt  r2, [r0], #4)
+2:             tst     r1, #2                  @ 1x 1x 0x 0x 1x 1x 0x
+USER(          strnebt r2, [r0], #1)
+USER(          strnebt r2, [r0], #1)
+               tst     r1, #1                  @ x1 x0 x1 x0 x1 x0 x1
+USER(          strnebt r2, [r0], #1)
+               mov     r0, #0
+               LOADREGS(fd,sp!, {r1, pc})
+
+               .section .fixup,"ax"
+               .align  0
+9001:          LOADREGS(fd,sp!, {r0, pc})
+               .previous
+