提交 a0752279 编写于 作者: M Mathieu Desnoyers 提交者: Linus Torvalds

local_t: i386 extension

Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 f43f7b46
......@@ -2,47 +2,198 @@
#define _ARCH_I386_LOCAL_H
#include <linux/percpu.h>
#include <asm/system.h>
#include <asm/atomic.h>
typedef struct
{
volatile long counter;
atomic_long_t a;
} local_t;
#define LOCAL_INIT(i) { (i) }
#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
#define local_read(v) ((v)->counter)
#define local_set(v,i) (((v)->counter) = (i))
#define local_read(l) atomic_long_read(&(l)->a)
#define local_set(l,i) atomic_long_set(&(l)->a, (i))
static __inline__ void local_inc(local_t *v)
static __inline__ void local_inc(local_t *l)
{
__asm__ __volatile__(
"incl %0"
:"+m" (v->counter));
:"+m" (l->a.counter));
}
static __inline__ void local_dec(local_t *v)
static __inline__ void local_dec(local_t *l)
{
__asm__ __volatile__(
"decl %0"
:"+m" (v->counter));
:"+m" (l->a.counter));
}
static __inline__ void local_add(long i, local_t *v)
static __inline__ void local_add(long i, local_t *l)
{
__asm__ __volatile__(
"addl %1,%0"
:"+m" (v->counter)
:"+m" (l->a.counter)
:"ir" (i));
}
static __inline__ void local_sub(long i, local_t *v)
static __inline__ void local_sub(long i, local_t *l)
{
__asm__ __volatile__(
"subl %1,%0"
:"+m" (v->counter)
:"+m" (l->a.counter)
:"ir" (i));
}
/**
* local_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @l: pointer of type local_t
*
* Atomically subtracts @i from @l and returns
* true if the result is zero, or false for all
* other cases.
*/
static __inline__ int local_sub_and_test(long i, local_t *l)
{
unsigned char c;
__asm__ __volatile__(
"subl %2,%0; sete %1"
:"+m" (l->a.counter), "=qm" (c)
:"ir" (i) : "memory");
return c;
}
/**
* local_dec_and_test - decrement and test
* @l: pointer of type local_t
*
* Atomically decrements @l by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
static __inline__ int local_dec_and_test(local_t *l)
{
unsigned char c;
__asm__ __volatile__(
"decl %0; sete %1"
:"+m" (l->a.counter), "=qm" (c)
: : "memory");
return c != 0;
}
/**
* 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.
*/
static __inline__ int local_inc_and_test(local_t *l)
{
unsigned char c;
__asm__ __volatile__(
"incl %0; sete %1"
:"+m" (l->a.counter), "=qm" (c)
: : "memory");
return c != 0;
}
/**
* local_add_negative - add and test if negative
* @l: pointer of type local_t
* @i: integer value to add
*
* Atomically adds @i to @l and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
static __inline__ int local_add_negative(long i, local_t *l)
{
unsigned char c;
__asm__ __volatile__(
"addl %2,%0; sets %1"
:"+m" (l->a.counter), "=qm" (c)
:"ir" (i) : "memory");
return c;
}
/**
* local_add_return - add and return
* @l: pointer of type local_t
* @i: integer value to add
*
* Atomically adds @i to @l and returns @i + @l
*/
static __inline__ long local_add_return(long i, local_t *l)
{
long __i;
#ifdef CONFIG_M386
unsigned long flags;
if(unlikely(boot_cpu_data.x86==3))
goto no_xadd;
#endif
/* Modern 486+ processor */
__i = i;
__asm__ __volatile__(
"xaddl %0, %1;"
:"+r" (i), "+m" (l->a.counter)
: : "memory");
return i + __i;
#ifdef CONFIG_M386
no_xadd: /* Legacy 386 processor */
local_irq_save(flags);
__i = local_read(l);
local_set(l, i + __i);
local_irq_restore(flags);
return i + __i;
#endif
}
static __inline__ long local_sub_return(long i, local_t *l)
{
return local_add_return(-i,l);
}
#define local_inc_return(l) (local_add_return(1,l))
#define local_dec_return(l) (local_sub_return(1,l))
#define local_cmpxchg(l, o, n) \
(cmpxchg_local(&((l)->a.counter), (o), (n)))
/* Always has a lock prefix */
#define local_xchg(l, n) (xchg(&((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 l...
* @u: ...unless l 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.
*/
#define local_add_unless(l, a, u) \
({ \
long c, old; \
c = local_read(l); \
for (;;) { \
if (unlikely(c == (u))) \
break; \
old = local_cmpxchg((l), c, c + (a)); \
if (likely(old == c)) \
break; \
c = old; \
} \
c != (u); \
})
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
/* On x86, these are no better than the atomic variants. */
#define __local_inc(l) local_inc(l)
#define __local_dec(l) local_dec(l)
......@@ -56,27 +207,27 @@ static __inline__ void local_sub(long i, local_t *v)
/* 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(v) \
#define cpu_local_wrap_v(l) \
({ local_t res__; \
preempt_disable(); \
res__ = (v); \
res__ = (l); \
preempt_enable(); \
res__; })
#define cpu_local_wrap(v) \
#define cpu_local_wrap(l) \
({ preempt_disable(); \
v; \
l; \
preempt_enable(); }) \
#define cpu_local_read(v) cpu_local_wrap_v(local_read(&__get_cpu_var(v)))
#define cpu_local_set(v, i) cpu_local_wrap(local_set(&__get_cpu_var(v), (i)))
#define cpu_local_inc(v) cpu_local_wrap(local_inc(&__get_cpu_var(v)))
#define cpu_local_dec(v) cpu_local_wrap(local_dec(&__get_cpu_var(v)))
#define cpu_local_add(i, v) cpu_local_wrap(local_add((i), &__get_cpu_var(v)))
#define cpu_local_sub(i, v) cpu_local_wrap(local_sub((i), &__get_cpu_var(v)))
#define __cpu_local_inc(v) cpu_local_inc(v)
#define __cpu_local_dec(v) cpu_local_dec(v)
#define __cpu_local_add(i, v) cpu_local_add((i), (v))
#define __cpu_local_sub(i, v) cpu_local_sub((i), (v))
#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_I386_LOCAL_H */
......@@ -305,6 +305,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
#define sync_cmpxchg(ptr,o,n)\
((__typeof__(*(ptr)))__sync_cmpxchg((ptr),(unsigned long)(o),\
(unsigned long)(n),sizeof(*(ptr))))
#define cmpxchg_local(ptr,o,n)\
((__typeof__(*(ptr)))__cmpxchg_local((ptr),(unsigned long)(o),\
(unsigned long)(n),sizeof(*(ptr))))
#endif
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
......@@ -367,6 +370,33 @@ static inline unsigned long __sync_cmpxchg(volatile void *ptr,
return old;
}
static inline unsigned long __cmpxchg_local(volatile void *ptr,
unsigned long old, unsigned long new, int size)
{
unsigned long prev;
switch (size) {
case 1:
__asm__ __volatile__("cmpxchgb %b1,%2"
: "=a"(prev)
: "q"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
case 2:
__asm__ __volatile__("cmpxchgw %w1,%2"
: "=a"(prev)
: "r"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
case 4:
__asm__ __volatile__("cmpxchgl %1,%2"
: "=a"(prev)
: "r"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
}
return old;
}
#ifndef CONFIG_X86_CMPXCHG
/*
* Building a kernel capable running on 80386. It may be necessary to
......@@ -403,6 +433,17 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
(unsigned long)(n), sizeof(*(ptr))); \
__ret; \
})
#define cmpxchg_local(ptr,o,n) \
({ \
__typeof__(*(ptr)) __ret; \
if (likely(boot_cpu_data.x86 > 3)) \
__ret = __cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))); \
else \
__ret = cmpxchg_386((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))); \
__ret; \
})
#endif
#ifdef CONFIG_X86_CMPXCHG64
......@@ -421,10 +462,26 @@ static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long l
return prev;
}
static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
unsigned long long old, unsigned long long new)
{
unsigned long long prev;
__asm__ __volatile__("cmpxchg8b %3"
: "=A"(prev)
: "b"((unsigned long)new),
"c"((unsigned long)(new >> 32)),
"m"(*__xg(ptr)),
"0"(old)
: "memory");
return prev;
}
#define cmpxchg64(ptr,o,n)\
((__typeof__(*(ptr)))__cmpxchg64((ptr),(unsigned long long)(o),\
(unsigned long long)(n)))
#define cmpxchg64_local(ptr,o,n)\
((__typeof__(*(ptr)))__cmpxchg64_local((ptr),(unsigned long long)(o),\
(unsigned long long)(n)))
#endif
/*
......
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