diff options
author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2006-09-26 06:32:13 (GMT) |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 15:48:54 (GMT) |
commit | 5f97f7f9400de47ae837170bb274e90ad3934386 (patch) | |
tree | 514451e6dc6b46253293a00035d375e77b1c65ed /include/asm-avr32/semaphore.h | |
parent | 53e62d3aaa60590d4a69b4e07c29f448b5151047 (diff) | |
download | linux-5f97f7f9400de47ae837170bb274e90ad3934386.tar.xz |
[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>
Diffstat (limited to 'include/asm-avr32/semaphore.h')
-rw-r--r-- | include/asm-avr32/semaphore.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/include/asm-avr32/semaphore.h b/include/asm-avr32/semaphore.h new file mode 100644 index 0000000..ef99ddc --- /dev/null +++ b/include/asm-avr32/semaphore.h @@ -0,0 +1,109 @@ +/* + * SMP- and interrupt-safe semaphores. + * + * Copyright (C) 2006 Atmel Corporation + * + * Based on include/asm-i386/semaphore.h + * Copyright (C) 1996 Linus Torvalds + * + * 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. + */ +#ifndef __ASM_AVR32_SEMAPHORE_H +#define __ASM_AVR32_SEMAPHORE_H + +#include <linux/linkage.h> + +#include <asm/system.h> +#include <asm/atomic.h> +#include <linux/wait.h> +#include <linux/rwsem.h> + +struct semaphore { + atomic_t count; + int sleepers; + wait_queue_head_t wait; +}; + +#define __SEMAPHORE_INITIALIZER(name, n) \ +{ \ + .count = ATOMIC_INIT(n), \ + .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ +} + +#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) + +#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) +#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) + +static inline void sema_init (struct semaphore *sem, int val) +{ + atomic_set(&sem->count, val); + sem->sleepers = 0; + init_waitqueue_head(&sem->wait); +} + +static inline void init_MUTEX (struct semaphore *sem) +{ + sema_init(sem, 1); +} + +static inline void init_MUTEX_LOCKED (struct semaphore *sem) +{ + sema_init(sem, 0); +} + +void __down(struct semaphore * sem); +int __down_interruptible(struct semaphore * sem); +void __up(struct semaphore * sem); + +/* + * This is ugly, but we want the default case to fall through. + * "__down_failed" is a special asm handler that calls the C + * routine that actually waits. See arch/i386/kernel/semaphore.c + */ +static inline void down(struct semaphore * sem) +{ + might_sleep(); + if (unlikely(atomic_dec_return (&sem->count) < 0)) + __down (sem); +} + +/* + * Interruptible try to acquire a semaphore. If we obtained + * it, return zero. If we were interrupted, returns -EINTR + */ +static inline int down_interruptible(struct semaphore * sem) +{ + int ret = 0; + + might_sleep(); + if (unlikely(atomic_dec_return (&sem->count) < 0)) + ret = __down_interruptible (sem); + return ret; +} + +/* + * Non-blockingly attempt to down() a semaphore. + * Returns zero if we acquired it + */ +static inline int down_trylock(struct semaphore * sem) +{ + return atomic_dec_if_positive(&sem->count) < 0; +} + +/* + * Note! This is subtle. We jump to wake people up only if + * the semaphore was negative (== somebody was waiting on it). + * The default case (no contention) will result in NO + * jumps for both down() and up(). + */ +static inline void up(struct semaphore * sem) +{ + if (unlikely(atomic_inc_return (&sem->count) <= 0)) + __up (sem); +} + +#endif /*__ASM_AVR32_SEMAPHORE_H */ |