mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-30 21:46:31 +00:00
da5311258d
When a process changes CPUs while doing the non atomic cpu_local_* operations it might operate on the local_t of a different CPUs. Fix that by disabling preemption. Pointed out by Christopher Lameter Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
#ifndef _ARCH_I386_LOCAL_H
|
|
#define _ARCH_I386_LOCAL_H
|
|
|
|
#include <linux/percpu.h>
|
|
|
|
typedef struct
|
|
{
|
|
volatile long counter;
|
|
} local_t;
|
|
|
|
#define LOCAL_INIT(i) { (i) }
|
|
|
|
#define local_read(v) ((v)->counter)
|
|
#define local_set(v,i) (((v)->counter) = (i))
|
|
|
|
static __inline__ void local_inc(local_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
"incl %0"
|
|
:"=m" (v->counter)
|
|
:"m" (v->counter));
|
|
}
|
|
|
|
static __inline__ void local_dec(local_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
"decl %0"
|
|
:"=m" (v->counter)
|
|
:"m" (v->counter));
|
|
}
|
|
|
|
static __inline__ void local_add(long i, local_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
"addl %1,%0"
|
|
:"=m" (v->counter)
|
|
:"ir" (i), "m" (v->counter));
|
|
}
|
|
|
|
static __inline__ void local_sub(long i, local_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
"subl %1,%0"
|
|
:"=m" (v->counter)
|
|
:"ir" (i), "m" (v->counter));
|
|
}
|
|
|
|
/* On x86, these are no better than the atomic variants. */
|
|
#define __local_inc(l) local_inc(l)
|
|
#define __local_dec(l) local_dec(l)
|
|
#define __local_add(i,l) local_add((i),(l))
|
|
#define __local_sub(i,l) local_sub((i),(l))
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
/* 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) \
|
|
({ local_t res__; \
|
|
preempt_disable(); \
|
|
res__ = (v); \
|
|
preempt_enable(); \
|
|
res__; })
|
|
#define cpu_local_wrap(v) \
|
|
({ preempt_disable(); \
|
|
v; \
|
|
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))
|
|
|
|
#endif /* _ARCH_I386_LOCAL_H */
|