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-rw-r--r--arch/avr32/lib/clear_user.S76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/avr32/lib/clear_user.S b/arch/avr32/lib/clear_user.S
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+++ b/arch/avr32/lib/clear_user.S
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+/*
+ * Copyright 2004-2006 Atmel Corporation
+ *
+ * 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 <asm/page.h>
+#include <asm/thread_info.h>
+#include <asm/asm.h>
+
+ .text
+ .align 1
+ .global clear_user
+ .type clear_user, "function"
+clear_user:
+ branch_if_kernel r8, __clear_user
+ ret_if_privileged r8, r12, r11, r11
+
+ .global __clear_user
+ .type __clear_user, "function"
+__clear_user:
+ mov r9, r12
+ mov r8, 0
+ andl r9, 3, COH
+ brne 5f
+
+1: sub r11, 4
+ brlt 2f
+
+10: st.w r12++, r8
+ sub r11, 4
+ brge 10b
+
+2: sub r11, -4
+ reteq 0
+
+ /* Unaligned count or address */
+ bld r11, 1
+ brcc 12f
+11: st.h r12++, r8
+ sub r11, 2
+ reteq 0
+12: st.b r12++, r8
+ retal 0
+
+ /* Unaligned address */
+5: cp.w r11, 4
+ brlt 2b
+
+ lsl r9, 2
+ add pc, pc, r9
+13: st.b r12++, r8
+ sub r11, 1
+14: st.b r12++, r8
+ sub r11, 1
+15: st.b r12++, r8
+ sub r11, 1
+ rjmp 1b
+
+ .size clear_user, . - clear_user
+ .size __clear_user, . - __clear_user
+
+ .section .fixup, "ax"
+ .align 1
+18: sub r11, -4
+19: retal r11
+
+ .section __ex_table, "a"
+ .align 2
+ .long 10b, 18b
+ .long 11b, 19b
+ .long 12b, 19b
+ .long 13b, 19b
+ .long 14b, 19b
+ .long 15b, 19b