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linux/arch/avr32/lib/clear_user.S

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[PATCH] avr32 architecture This adds support for the Atmel AVR32 architecture as well as the AT32AP7000 CPU and the AT32STK1000 development board. AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for cost-sensitive embedded applications, with particular emphasis on low power consumption and high code density. The AVR32 architecture is not binary compatible with earlier 8-bit AVR architectures. The AVR32 architecture, including the instruction set, is described by the AVR32 Architecture Manual, available from http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It features a 7-stage pipeline, 16KB instruction and data caches and a full Memory Management Unit. It also comes with a large set of integrated peripherals, many of which are shared with the AT91 ARM-based controllers from Atmel. Full data sheet is available from http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf while the CPU core implementation including caches and MMU is documented by the AVR32 AP Technical Reference, available from http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf Information about the AT32STK1000 development board can be found at http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918 including a BSP CD image with an earlier version of this patch, development tools (binaries and source/patches) and a root filesystem image suitable for booting from SD card. Alternatively, there's a preliminary "getting started" guide available at http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links to the sources and patches you will need in order to set up a cross-compiling environment for avr32-linux. This patch, as well as the other patches included with the BSP and the toolchain patches, is actively supported by Atmel Corporation. [dmccr@us.ibm.com: Fix more pxx_page macro locations] [bunk@stusta.de: fix `make defconfig'] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Dave McCracken <dmccr@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 14:32:13 +08:00
/*
* 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
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