* [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile [not found] <d6775e129db48371cdf86e94ddfaa1d15617bb8f.1186773842.git.segher@kernel.crashing.org> @ 2007-08-11 0:15 ` Segher Boessenkool 2007-08-11 0:36 ` Paul Mackerras 2007-08-17 0:43 ` Paul Mackerras 0 siblings, 2 replies; 4+ messages in thread From: Segher Boessenkool @ 2007-08-11 0:15 UTC (permalink / raw) To: linuxppc-dev; +Cc: linux-arch, paulus, linux-kernel Instead, use asm() like all other atomic operations already do. Also use inline functions instead of macros; this actually improves code generation (some code becomes a little smaller, probably because of improved alias information -- just a few hundred bytes total on a default kernel build, nothing shocking). Signed-off-by: Segher Boessenkool <segher@kernel•crashing.org> --- include/asm-powerpc/atomic.h | 34 ++++++++++++++++++++++++++++------ 1 files changed, 28 insertions(+), 6 deletions(-) diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h index c44810b..bc17506 100644 --- a/include/asm-powerpc/atomic.h +++ b/include/asm-powerpc/atomic.h @@ -5,7 +5,7 @@ * PowerPC atomic operations */ -typedef struct { volatile int counter; } atomic_t; +typedef struct { int counter; } atomic_t; #ifdef __KERNEL__ #include <linux/compiler.h> @@ -15,8 +15,19 @@ typedef struct { volatile int counter; } atomic_t; #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) -#define atomic_set(v,i) (((v)->counter) = (i)) +static __inline__ int atomic_read(const atomic_t *v) +{ + int t; + + __asm__ __volatile__("lwz%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter)); + + return t; +} + +static __inline__ void atomic_set(atomic_t *v, int i) +{ + __asm__ __volatile__("stw%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i)); +} static __inline__ void atomic_add(int a, atomic_t *v) { @@ -240,12 +251,23 @@ static __inline__ int atomic_dec_if_positive(atomic_t *v) #ifdef __powerpc64__ -typedef struct { volatile long counter; } atomic64_t; +typedef struct { long counter; } atomic64_t; #define ATOMIC64_INIT(i) { (i) } -#define atomic64_read(v) ((v)->counter) -#define atomic64_set(v,i) (((v)->counter) = (i)) +static __inline__ long atomic64_read(const atomic_t *v) +{ + long t; + + __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter)); + + return t; +} + +static __inline__ void atomic64_set(atomic_t *v, long i) +{ + __asm__ __volatile__("std%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i)); +} static __inline__ void atomic64_add(long a, atomic64_t *v) { -- 1.5.2.1.144.gabc40-dirty ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile 2007-08-11 0:15 ` [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile Segher Boessenkool @ 2007-08-11 0:36 ` Paul Mackerras 2007-08-17 0:43 ` Paul Mackerras 1 sibling, 0 replies; 4+ messages in thread From: Paul Mackerras @ 2007-08-11 0:36 UTC (permalink / raw) To: Segher Boessenkool; +Cc: linux-arch, linuxppc-dev, linux-kernel Segher Boessenkool writes: > Instead, use asm() like all other atomic operations already do. > > Also use inline functions instead of macros; this actually > improves code generation (some code becomes a little smaller, > probably because of improved alias information -- just a few > hundred bytes total on a default kernel build, nothing shocking). > > Signed-off-by: Segher Boessenkool <segher@kernel•crashing.org> Looks OK to me. In the hope that Chris Snook will pick it up and include it with his other atomic changes: Acked-by: Paul Mackerras <paulus@samba•org> ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile 2007-08-11 0:15 ` [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile Segher Boessenkool 2007-08-11 0:36 ` Paul Mackerras @ 2007-08-17 0:43 ` Paul Mackerras 2007-08-18 1:29 ` Segher Boessenkool 1 sibling, 1 reply; 4+ messages in thread From: Paul Mackerras @ 2007-08-17 0:43 UTC (permalink / raw) To: Segher Boessenkool; +Cc: linux-arch, linuxppc-dev, linux-kernel Segher Boessenkool writes: > Instead, use asm() like all other atomic operations already do. > +static __inline__ long atomic64_read(const atomic_t *v) > +static __inline__ void atomic64_set(atomic_t *v, long i) s/atomic_t/atomic64_t/ in both lines. I've edited my copy of the patch. Paul. ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile 2007-08-17 0:43 ` Paul Mackerras @ 2007-08-18 1:29 ` Segher Boessenkool 0 siblings, 0 replies; 4+ messages in thread From: Segher Boessenkool @ 2007-08-18 1:29 UTC (permalink / raw) To: Paul Mackerras; +Cc: linux-arch, linuxppc-dev, linux-kernel >> Instead, use asm() like all other atomic operations already do. > >> +static __inline__ long atomic64_read(const atomic_t *v) > >> +static __inline__ void atomic64_set(atomic_t *v, long i) > > s/atomic_t/atomic64_t/ in both lines. I've edited my copy of the > patch. Ouch, sorry about that. Segher ^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] <d6775e129db48371cdf86e94ddfaa1d15617bb8f.1186773842.git.segher@kernel.crashing.org>
2007-08-11 0:15 ` [PATCH] powerpc: Implement atomic{, 64}_{read, write}() without volatile Segher Boessenkool
2007-08-11 0:36 ` Paul Mackerras
2007-08-17 0:43 ` Paul Mackerras
2007-08-18 1:29 ` Segher Boessenkool
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