From: Mathieu Desnoyers Date: Tue, 8 May 2007 07:34:53 +0000 (-0700) Subject: local_t: powerpc extension X-Git-Tag: v2.6.22-rc1~534 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6d8944a0d7fa59e4db0d7b792e6138043ee0ad2c;p=linux-2.6 local_t: powerpc extension [akpm@linux-foundation.org: build fixes] Signed-off-by: Mathieu Desnoyers Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/asm-powerpc/local.h b/include/asm-powerpc/local.h index c11c530f74..612d832766 100644 --- a/include/asm-powerpc/local.h +++ b/include/asm-powerpc/local.h @@ -1 +1,200 @@ -#include +#ifndef _ARCH_POWERPC_LOCAL_H +#define _ARCH_POWERPC_LOCAL_H + +#include +#include + +typedef struct +{ + atomic_long_t a; +} local_t; + +#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } + +#define local_read(l) atomic_long_read(&(l)->a) +#define local_set(l,i) atomic_long_set(&(l)->a, (i)) + +#define local_add(i,l) atomic_long_add((i),(&(l)->a)) +#define local_sub(i,l) atomic_long_sub((i),(&(l)->a)) +#define local_inc(l) atomic_long_inc(&(l)->a) +#define local_dec(l) atomic_long_dec(&(l)->a) + +static __inline__ long local_add_return(long a, local_t *l) +{ + long t; + + __asm__ __volatile__( +"1:" PPC_LLARX "%0,0,%2 # local_add_return\n\ + add %0,%1,%0\n" + PPC405_ERR77(0,%2) + PPC_STLCX "%0,0,%2 \n\ + bne- 1b" + : "=&r" (t) + : "r" (a), "r" (&(l->a.counter)) + : "cc", "memory"); + + return t; +} + +#define local_add_negative(a, l) (local_add_return((a), (l)) < 0) + +static __inline__ long local_sub_return(long a, local_t *l) +{ + long t; + + __asm__ __volatile__( +"1:" PPC_LLARX "%0,0,%2 # local_sub_return\n\ + subf %0,%1,%0\n" + PPC405_ERR77(0,%2) + PPC_STLCX "%0,0,%2 \n\ + bne- 1b" + : "=&r" (t) + : "r" (a), "r" (&(l->a.counter)) + : "cc", "memory"); + + return t; +} + +static __inline__ long local_inc_return(local_t *l) +{ + long t; + + __asm__ __volatile__( +"1:" PPC_LLARX "%0,0,%1 # local_inc_return\n\ + addic %0,%0,1\n" + PPC405_ERR77(0,%1) + PPC_STLCX "%0,0,%1 \n\ + bne- 1b" + : "=&r" (t) + : "r" (&(l->a.counter)) + : "cc", "memory"); + + return t; +} + +/* + * local_inc_and_test - increment and test + * @l: pointer of type local_t + * + * Atomically increments @l by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +#define local_inc_and_test(l) (local_inc_return(l) == 0) + +static __inline__ long local_dec_return(local_t *l) +{ + long t; + + __asm__ __volatile__( +"1:" PPC_LLARX "%0,0,%1 # local_dec_return\n\ + addic %0,%0,-1\n" + PPC405_ERR77(0,%1) + PPC_STLCX "%0,0,%1\n\ + bne- 1b" + : "=&r" (t) + : "r" (&(l->a.counter)) + : "cc", "memory"); + + return t; +} + +#define local_cmpxchg(l, o, n) \ + (cmpxchg_local(&((l)->a.counter), (o), (n))) +#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n))) + +/** + * local_add_unless - add unless the number is a given value + * @l: pointer of type local_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @l, so long as it was not @u. + * Returns non-zero if @l was not @u, and zero otherwise. + */ +static __inline__ int local_add_unless(local_t *l, long a, long u) +{ + long t; + + __asm__ __volatile__ ( +"1:" PPC_LLARX "%0,0,%1 # local_add_unless\n\ + cmpw 0,%0,%3 \n\ + beq- 2f \n\ + add %0,%2,%0 \n" + PPC405_ERR77(0,%2) + PPC_STLCX "%0,0,%1 \n\ + bne- 1b \n" +" subf %0,%2,%0 \n\ +2:" + : "=&r" (t) + : "r" (&(l->a.counter)), "r" (a), "r" (u) + : "cc", "memory"); + + return t != u; +} + +#define local_inc_not_zero(l) local_add_unless((l), 1, 0) + +#define local_sub_and_test(a, l) (local_sub_return((a), (l)) == 0) +#define local_dec_and_test(l) (local_dec_return((l)) == 0) + +/* + * Atomically test *l and decrement if it is greater than 0. + * The function returns the old value of *l minus 1. + */ +static __inline__ long local_dec_if_positive(local_t *l) +{ + long t; + + __asm__ __volatile__( +"1:" PPC_LLARX "%0,0,%1 # local_dec_if_positive\n\ + cmpwi %0,1\n\ + addi %0,%0,-1\n\ + blt- 2f\n" + PPC405_ERR77(0,%1) + PPC_STLCX "%0,0,%1\n\ + bne- 1b" + "\n\ +2:" : "=&b" (t) + : "r" (&(l->a.counter)) + : "cc", "memory"); + + return t; +} + +/* Use these for per-cpu local_t variables: on some archs they are + * much more efficient than these naive implementations. Note they take + * a variable, not an address. + */ + +#define __local_inc(l) ((l)->a.counter++) +#define __local_dec(l) ((l)->a.counter++) +#define __local_add(i,l) ((l)->a.counter+=(i)) +#define __local_sub(i,l) ((l)->a.counter-=(i)) + +/* Need to disable preemption for the cpu local counters otherwise we could + still access a variable of a previous CPU in a non atomic way. */ +#define cpu_local_wrap_v(l) \ + ({ local_t res__; \ + preempt_disable(); \ + res__ = (l); \ + preempt_enable(); \ + res__; }) +#define cpu_local_wrap(l) \ + ({ preempt_disable(); \ + l; \ + preempt_enable(); }) \ + +#define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l))) +#define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i))) +#define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l))) +#define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l))) +#define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l))) +#define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l))) + +#define __cpu_local_inc(l) cpu_local_inc(l) +#define __cpu_local_dec(l) cpu_local_dec(l) +#define __cpu_local_add(i, l) cpu_local_add((i), (l)) +#define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) + +#endif /* _ARCH_POWERPC_LOCAL_H */