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linux-next/arch/avr32/lib/copy_user.S
Haavard Skinnemoen 5f97f7f940 [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 08:48:54 -07:00

120 lines
2.2 KiB
ArmAsm

/*
* 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 <asm/page.h>
#include <asm/thread_info.h>
#include <asm/asm.h>
/*
* __kernel_size_t
* __copy_user(void *to, const void *from, __kernel_size_t n)
*
* Returns the number of bytes not copied. Might be off by
* max 3 bytes if we get a fault in the main loop.
*
* The address-space checking functions simply fall through to
* the non-checking version.
*/
.text
.align 1
.global copy_from_user
.type copy_from_user, @function
copy_from_user:
branch_if_kernel r8, __copy_user
ret_if_privileged r8, r11, r10, r10
rjmp __copy_user
.size copy_from_user, . - copy_from_user
.global copy_to_user
.type copy_to_user, @function
copy_to_user:
branch_if_kernel r8, __copy_user
ret_if_privileged r8, r12, r10, r10
.size copy_to_user, . - copy_to_user
.global __copy_user
.type __copy_user, @function
__copy_user:
mov r9, r11
andl r9, 3, COH
brne 6f
/* At this point, from is word-aligned */
1: sub r10, 4
brlt 3f
2:
10: ld.w r8, r11++
11: st.w r12++, r8
sub r10, 4
brge 2b
3: sub r10, -4
reteq 0
/*
* Handle unaligned count. Need to be careful with r10 here so
* that we return the correct value even if we get a fault
*/
4:
20: ld.ub r8, r11++
21: st.b r12++, r8
sub r10, 1
reteq 0
22: ld.ub r8, r11++
23: st.b r12++, r8
sub r10, 1
reteq 0
24: ld.ub r8, r11++
25: st.b r12++, r8
retal 0
/* Handle unaligned from-pointer */
6: cp.w r10, 4
brlt 4b
rsub r9, r9, 4
30: ld.ub r8, r11++
31: st.b r12++, r8
sub r10, 1
sub r9, 1
breq 1b
32: ld.ub r8, r11++
33: st.b r12++, r8
sub r10, 1
sub r9, 1
breq 1b
34: ld.ub r8, r11++
35: st.b r12++, r8
sub r10, 1
rjmp 1b
.size __copy_user, . - __copy_user
.section .fixup,"ax"
.align 1
19: sub r10, -4
29: retal r10
.section __ex_table,"a"
.align 2
.long 10b, 19b
.long 11b, 19b
.long 20b, 29b
.long 21b, 29b
.long 22b, 29b
.long 23b, 29b
.long 24b, 29b
.long 25b, 29b
.long 30b, 29b
.long 31b, 29b
.long 32b, 29b
.long 33b, 29b
.long 34b, 29b
.long 35b, 29b