mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-21 10:05:00 +08:00
a79f0da80a
Now atomic64_read() is light weight (no register pressure and
small icache), we can inline it again.
Also use "=&A" constraint instead of "+A" to avoid warning
about unitialized 'res' variable. (gcc had to force 0 in eax/edx)
$ size vmlinux.prev vmlinux.after
text data bss dec hex filename
4908667 451676 1684868 7045211 6b805b vmlinux.prev
4908651 451676 1684868 7045195 6b804b vmlinux.after
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <4A4E1AA2.30002@gmail.com>
[ Also fix typo in atomic64_set() export ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
416 lines
9.6 KiB
C
416 lines
9.6 KiB
C
#ifndef _ASM_X86_ATOMIC_32_H
|
|
#define _ASM_X86_ATOMIC_32_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/cmpxchg.h>
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*/
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
/**
|
|
* atomic_read - read atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically reads the value of @v.
|
|
*/
|
|
static inline int atomic_read(const atomic_t *v)
|
|
{
|
|
return v->counter;
|
|
}
|
|
|
|
/**
|
|
* atomic_set - set atomic variable
|
|
* @v: pointer of type atomic_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i.
|
|
*/
|
|
static inline void atomic_set(atomic_t *v, int i)
|
|
{
|
|
v->counter = i;
|
|
}
|
|
|
|
/**
|
|
* atomic_add - add integer to atomic variable
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v.
|
|
*/
|
|
static inline void atomic_add(int i, atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "addl %1,%0"
|
|
: "+m" (v->counter)
|
|
: "ir" (i));
|
|
}
|
|
|
|
/**
|
|
* atomic_sub - subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "subl %1,%0"
|
|
: "+m" (v->counter)
|
|
: "ir" (i));
|
|
}
|
|
|
|
/**
|
|
* atomic_sub_and_test - subtract value from variable and test result
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static inline int atomic_sub_and_test(int i, atomic_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
|
|
: "+m" (v->counter), "=qm" (c)
|
|
: "ir" (i) : "memory");
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* atomic_inc - increment atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
static inline void atomic_inc(atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "incl %0"
|
|
: "+m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic_dec - decrement atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
static inline void atomic_dec(atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "decl %0"
|
|
: "+m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic_dec_and_test - decrement and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
static inline int atomic_dec_and_test(atomic_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
asm volatile(LOCK_PREFIX "decl %0; sete %1"
|
|
: "+m" (v->counter), "=qm" (c)
|
|
: : "memory");
|
|
return c != 0;
|
|
}
|
|
|
|
/**
|
|
* atomic_inc_and_test - increment and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static inline int atomic_inc_and_test(atomic_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
asm volatile(LOCK_PREFIX "incl %0; sete %1"
|
|
: "+m" (v->counter), "=qm" (c)
|
|
: : "memory");
|
|
return c != 0;
|
|
}
|
|
|
|
/**
|
|
* atomic_add_negative - add and test if negative
|
|
* @v: pointer of type atomic_t
|
|
* @i: integer value to add
|
|
*
|
|
* Atomically adds @i to @v and returns true
|
|
* if the result is negative, or false when
|
|
* result is greater than or equal to zero.
|
|
*/
|
|
static inline int atomic_add_negative(int i, atomic_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
|
|
: "+m" (v->counter), "=qm" (c)
|
|
: "ir" (i) : "memory");
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* atomic_add_return - add integer and return
|
|
* @v: pointer of type atomic_t
|
|
* @i: integer value to add
|
|
*
|
|
* Atomically adds @i to @v and returns @i + @v
|
|
*/
|
|
static inline int atomic_add_return(int i, atomic_t *v)
|
|
{
|
|
int __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(LOCK_PREFIX "xaddl %0, %1"
|
|
: "+r" (i), "+m" (v->counter)
|
|
: : "memory");
|
|
return i + __i;
|
|
|
|
#ifdef CONFIG_M386
|
|
no_xadd: /* Legacy 386 processor */
|
|
local_irq_save(flags);
|
|
__i = atomic_read(v);
|
|
atomic_set(v, i + __i);
|
|
local_irq_restore(flags);
|
|
return i + __i;
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* atomic_sub_return - subtract integer and return
|
|
* @v: pointer of type atomic_t
|
|
* @i: integer value to subtract
|
|
*
|
|
* Atomically subtracts @i from @v and returns @v - @i
|
|
*/
|
|
static inline int atomic_sub_return(int i, atomic_t *v)
|
|
{
|
|
return atomic_add_return(-i, v);
|
|
}
|
|
|
|
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
|
|
{
|
|
return cmpxchg(&v->counter, old, new);
|
|
}
|
|
|
|
static inline int atomic_xchg(atomic_t *v, int new)
|
|
{
|
|
return xchg(&v->counter, new);
|
|
}
|
|
|
|
/**
|
|
* atomic_add_unless - add unless the number is already a given value
|
|
* @v: pointer of type atomic_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as @v was not already @u.
|
|
* Returns non-zero if @v was not @u, and zero otherwise.
|
|
*/
|
|
static inline int atomic_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int c, old;
|
|
c = atomic_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
#define atomic_inc_return(v) (atomic_add_return(1, v))
|
|
#define atomic_dec_return(v) (atomic_sub_return(1, v))
|
|
|
|
/* These are x86-specific, used by some header files */
|
|
#define atomic_clear_mask(mask, addr) \
|
|
asm volatile(LOCK_PREFIX "andl %0,%1" \
|
|
: : "r" (~(mask)), "m" (*(addr)) : "memory")
|
|
|
|
#define atomic_set_mask(mask, addr) \
|
|
asm volatile(LOCK_PREFIX "orl %0,%1" \
|
|
: : "r" (mask), "m" (*(addr)) : "memory")
|
|
|
|
/* Atomic operations are already serializing on x86 */
|
|
#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()
|
|
|
|
/* An 64bit atomic type */
|
|
|
|
typedef struct {
|
|
u64 __aligned(8) counter;
|
|
} atomic64_t;
|
|
|
|
#define ATOMIC64_INIT(val) { (val) }
|
|
|
|
extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
|
|
|
|
/**
|
|
* atomic64_xchg - xchg atomic64 variable
|
|
* @ptr: pointer to type atomic64_t
|
|
* @new_val: value to assign
|
|
*
|
|
* Atomically xchgs the value of @ptr to @new_val and returns
|
|
* the old value.
|
|
*/
|
|
extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val);
|
|
|
|
/**
|
|
* atomic64_set - set atomic64 variable
|
|
* @ptr: pointer to type atomic64_t
|
|
* @new_val: value to assign
|
|
*
|
|
* Atomically sets the value of @ptr to @new_val.
|
|
*/
|
|
extern void atomic64_set(atomic64_t *ptr, u64 new_val);
|
|
|
|
/**
|
|
* atomic64_read - read atomic64 variable
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically reads the value of @ptr and returns it.
|
|
*/
|
|
static inline u64 atomic64_read(atomic64_t *ptr)
|
|
{
|
|
u64 res;
|
|
|
|
/*
|
|
* Note, we inline this atomic64_t primitive because
|
|
* it only clobbers EAX/EDX and leaves the others
|
|
* untouched. We also (somewhat subtly) rely on the
|
|
* fact that cmpxchg8b returns the current 64-bit value
|
|
* of the memory location we are touching:
|
|
*/
|
|
asm volatile(
|
|
"mov %%ebx, %%eax\n\t"
|
|
"mov %%ecx, %%edx\n\t"
|
|
LOCK_PREFIX "cmpxchg8b %1\n"
|
|
: "=&A" (res)
|
|
: "m" (*ptr)
|
|
);
|
|
|
|
return res;
|
|
}
|
|
|
|
extern u64 atomic64_read(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_add_return - add and return
|
|
* @delta: integer value to add
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @delta to @ptr and returns @delta + *@ptr
|
|
*/
|
|
extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr);
|
|
|
|
/*
|
|
* Other variants with different arithmetic operators:
|
|
*/
|
|
extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr);
|
|
extern u64 atomic64_inc_return(atomic64_t *ptr);
|
|
extern u64 atomic64_dec_return(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_add - add integer to atomic64 variable
|
|
* @delta: integer value to add
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @delta to @ptr.
|
|
*/
|
|
extern void atomic64_add(u64 delta, atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_sub - subtract the atomic64 variable
|
|
* @delta: integer value to subtract
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @delta from @ptr.
|
|
*/
|
|
extern void atomic64_sub(u64 delta, atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_sub_and_test - subtract value from variable and test result
|
|
* @delta: integer value to subtract
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @delta from @ptr and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_inc - increment atomic64 variable
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @ptr by 1.
|
|
*/
|
|
extern void atomic64_inc(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_dec - decrement atomic64 variable
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @ptr by 1.
|
|
*/
|
|
extern void atomic64_dec(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_dec_and_test - decrement and test
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @ptr by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
extern int atomic64_dec_and_test(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_inc_and_test - increment and test
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @ptr by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
extern int atomic64_inc_and_test(atomic64_t *ptr);
|
|
|
|
/**
|
|
* atomic64_add_negative - add and test if negative
|
|
* @delta: integer value to add
|
|
* @ptr: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @delta to @ptr and returns true
|
|
* if the result is negative, or false when
|
|
* result is greater than or equal to zero.
|
|
*/
|
|
extern int atomic64_add_negative(u64 delta, atomic64_t *ptr);
|
|
|
|
#include <asm-generic/atomic-long.h>
|
|
#endif /* _ASM_X86_ATOMIC_32_H */
|