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#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#include <xen/config.h>
#include <xen/lib.h>
static inline void dsb_sev(void)
{
__asm__ __volatile__ (
"dsb\n"
"sev\n"
);
}
typedef struct {
volatile unsigned int lock;
} raw_spinlock_t;
#define _RAW_SPIN_LOCK_UNLOCKED { 0 }
#define _raw_spin_is_locked(x) ((x)->lock != 0)
static always_inline void _raw_spin_unlock(raw_spinlock_t *lock)
{
ASSERT(_raw_spin_is_locked(lock));
smp_mb();
__asm__ __volatile__(
" str %1, [%0]\n"
:
: "r" (&lock->lock), "r" (0)
: "cc");
dsb_sev();
}
static always_inline int _raw_spin_trylock(raw_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
" ldrex %0, [%1]\n"
" teq %0, #0\n"
" strexeq %0, %2, [%1]"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (1)
: "cc");
if (tmp == 0) {
smp_mb();
return 1;
} else {
return 0;
}
}
typedef struct {
volatile unsigned int lock;
} raw_rwlock_t;
#define _RAW_RW_LOCK_UNLOCKED { 0 }
static always_inline int _raw_read_trylock(raw_rwlock_t *rw)
{
unsigned long tmp, tmp2 = 1;
__asm__ __volatile__(
"1: ldrex %0, [%2]\n"
" adds %0, %0, #1\n"
" strexpl %1, %0, [%2]\n"
: "=&r" (tmp), "+r" (tmp2)
: "r" (&rw->lock)
: "cc");
smp_mb();
return tmp2 == 0;
}
static always_inline int _raw_write_trylock(raw_rwlock_t *rw)
{
unsigned long tmp;
__asm__ __volatile__(
"1: ldrex %0, [%1]\n"
" teq %0, #0\n"
" strexeq %0, %2, [%1]"
: "=&r" (tmp)
: "r" (&rw->lock), "r" (0x80000000)
: "cc");
if (tmp == 0) {
smp_mb();
return 1;
} else {
return 0;
}
}
static inline void _raw_read_unlock(raw_rwlock_t *rw)
{
unsigned long tmp, tmp2;
smp_mb();
__asm__ __volatile__(
"1: ldrex %0, [%2]\n"
" sub %0, %0, #1\n"
" strex %1, %0, [%2]\n"
" teq %1, #0\n"
" bne 1b"
: "=&r" (tmp), "=&r" (tmp2)
: "r" (&rw->lock)
: "cc");
if (tmp == 0)
dsb_sev();
}
static inline void _raw_write_unlock(raw_rwlock_t *rw)
{
smp_mb();
__asm__ __volatile__(
"str %1, [%0]\n"
:
: "r" (&rw->lock), "r" (0)
: "cc");
dsb_sev();
}
#define _raw_rw_is_locked(x) ((x)->lock != 0)
#define _raw_rw_is_write_locked(x) ((x)->lock == 0x80000000)
#endif /* __ASM_SPINLOCK_H */
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* indent-tabs-mode: nil
* End:
*/
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