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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-cris/atomic.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-cris/atomic.h')
-rw-r--r-- | include/asm-cris/atomic.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h new file mode 100644 index 000000000000..b3dfea5a71e4 --- /dev/null +++ b/include/asm-cris/atomic.h @@ -0,0 +1,150 @@ +/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */ + +#ifndef __ASM_CRIS_ATOMIC__ +#define __ASM_CRIS_ATOMIC__ + +#include <asm/system.h> + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +/* + * Make sure gcc doesn't try to be clever and move things around + * on us. We need to use _exactly_ the address the user gave us, + * not some alias that contains the same information. + */ + +#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x) + +typedef struct { int counter; } atomic_t; + +#define ATOMIC_INIT(i) { (i) } + +#define atomic_read(v) ((v)->counter) +#define atomic_set(v,i) (((v)->counter) = (i)) + +/* These should be written in asm but we do it in C for now. */ + +extern __inline__ void atomic_add(int i, volatile atomic_t *v) +{ + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + v->counter += i; + local_irq_restore(flags); +} + +extern __inline__ void atomic_sub(int i, volatile atomic_t *v) +{ + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + v->counter -= i; + local_irq_restore(flags); +} + +extern __inline__ int atomic_add_return(int i, volatile atomic_t *v) +{ + unsigned long flags; + int retval; + local_save_flags(flags); + local_irq_disable(); + retval = (v->counter += i); + local_irq_restore(flags); + return retval; +} + +#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) + +extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v) +{ + unsigned long flags; + int retval; + local_save_flags(flags); + local_irq_disable(); + retval = (v->counter -= i); + local_irq_restore(flags); + return retval; +} + +extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v) +{ + int retval; + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + retval = (v->counter -= i) == 0; + local_irq_restore(flags); + return retval; +} + +extern __inline__ void atomic_inc(volatile atomic_t *v) +{ + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + (v->counter)++; + local_irq_restore(flags); +} + +extern __inline__ void atomic_dec(volatile atomic_t *v) +{ + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + (v->counter)--; + local_irq_restore(flags); +} + +extern __inline__ int atomic_inc_return(volatile atomic_t *v) +{ + unsigned long flags; + int retval; + local_save_flags(flags); + local_irq_disable(); + retval = (v->counter)++; + local_irq_restore(flags); + return retval; +} + +extern __inline__ int atomic_dec_return(volatile atomic_t *v) +{ + unsigned long flags; + int retval; + local_save_flags(flags); + local_irq_disable(); + retval = (v->counter)--; + local_irq_restore(flags); + return retval; +} +extern __inline__ int atomic_dec_and_test(volatile atomic_t *v) +{ + int retval; + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + retval = --(v->counter) == 0; + local_irq_restore(flags); + return retval; +} + +extern __inline__ int atomic_inc_and_test(volatile atomic_t *v) +{ + int retval; + unsigned long flags; + local_save_flags(flags); + local_irq_disable(); + retval = ++(v->counter) == 0; + local_irq_restore(flags); + return retval; +} + +/* Atomic operations are already serializing */ +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + +#endif |