linux/arch/avr32/lib/strncpy_from_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 06:32:13 +00:00
/*
* Copy to/from userspace with optional address space checking.
*
* 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 <linux/errno.h>
#include <asm/page.h>
#include <asm/thread_info.h>
#include <asm/asm.h>
/*
* long strncpy_from_user(char *dst, const char *src, long count)
*
* On success, returns the length of the string, not including
* the terminating NUL.
*
* If the string is longer than count, returns count
*
* If userspace access fails, returns -EFAULT
*/
.text
.align 1
.global strncpy_from_user
.type strncpy_from_user, "function"
strncpy_from_user:
mov r9, -EFAULT
branch_if_kernel r8, __strncpy_from_user
ret_if_privileged r8, r11, r10, r9
.global __strncpy_from_user
.type __strncpy_from_user, "function"
__strncpy_from_user:
cp.w r10, 0
reteq 0
mov r9, r10
1: ld.ub r8, r11++
st.b r12++, r8
cp.w r8, 0
breq 2f
sub r9, 1
brne 1b
2: sub r10, r9
retal r10
.section .fixup, "ax"
.align 1
3: mov r12, -EFAULT
retal r12
.section __ex_table, "a"
.align 2
.long 1b, 3b