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[PATCH] ARM SMP: Fix ARMv6 spinlock and semaphore implementations

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Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
2005-07-24 12:13:40 +01:00
committed by Russell King
parent 2c2a68b847
commit 4e8fd22bd4
2 changed files with 21 additions and 18 deletions
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4
include/asm-arm/locks.h
View File

@@ -61,7 +61,7 @@
" strex ip, lr, [%0]\n" \ " strex ip, lr, [%0]\n" \
" teq ip, #0\n" \ " teq ip, #0\n" \
" bne 1b\n" \ " bne 1b\n" \
" teq lr, #0\n" \ " cmp lr, #0\n" \
" movle ip, %0\n" \ " movle ip, %0\n" \
" blle " #wake \ " blle " #wake \
: \ : \
@@ -100,7 +100,7 @@
__asm__ __volatile__( \ __asm__ __volatile__( \
"@ up_op_read\n" \ "@ up_op_read\n" \
"1: ldrex lr, [%0]\n" \ "1: ldrex lr, [%0]\n" \
" add lr, lr, %1\n" \ " adds lr, lr, %1\n" \
" strex ip, lr, [%0]\n" \ " strex ip, lr, [%0]\n" \
" teq ip, #0\n" \ " teq ip, #0\n" \
" bne 1b\n" \ " bne 1b\n" \

35
include/asm-arm/spinlock.h
View File

@@ -79,7 +79,8 @@ typedef struct {
} rwlock_t; } rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } #define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
#define rwlock_init(x) do { *(x) + RW_LOCK_UNLOCKED; } while (0) #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while (0)
#define rwlock_is_locked(x) (*((volatile unsigned int *)(x)) != 0)
/* /*
* Write locks are easy - we just set bit 31. When unlocking, we can * Write locks are easy - we just set bit 31. When unlocking, we can
@@ -100,6 +101,21 @@ static inline void _raw_write_lock(rwlock_t *rw)
: "cc", "memory"); : "cc", "memory");
} }
static inline int _raw_write_trylock(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", "memory");
return tmp == 0;
}
static inline void _raw_write_unlock(rwlock_t *rw) static inline void _raw_write_unlock(rwlock_t *rw)
{ {
__asm__ __volatile__( __asm__ __volatile__(
@@ -138,6 +154,8 @@ static inline void _raw_read_lock(rwlock_t *rw)
static inline void _raw_read_unlock(rwlock_t *rw) static inline void _raw_read_unlock(rwlock_t *rw)
{ {
unsigned long tmp, tmp2;
__asm__ __volatile__( __asm__ __volatile__(
"1: ldrex %0, [%2]\n" "1: ldrex %0, [%2]\n"
" sub %0, %0, #1\n" " sub %0, %0, #1\n"
@@ -151,19 +169,4 @@ static inline void _raw_read_unlock(rwlock_t *rw)
#define _raw_read_trylock(lock) generic_raw_read_trylock(lock) #define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
static inline int _raw_write_trylock(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", "memory");
return tmp == 0;
}
#endif /* __ASM_SPINLOCK_H */ #endif /* __ASM_SPINLOCK_H */