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OpenCloudOS-Kernel
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[SPARC64]: Implement __raw_read_trylock() 

generic__raw_read_trylock() just does a raw_read_lock() so that
isn't very useful.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-01-23 21:03:56 -08:00
parent 4415863773
commit d3ed309a71
1 changed files with 23 additions and 1 deletions
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24
include/asm-sparc64/spinlock.h
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@ -131,6 +131,28 @@ static void inline __read_lock(raw_rwlock_t *lock)
: "memory");
}
static int inline __read_trylock(raw_rwlock_t *lock)
{
int tmp1, tmp2;
__asm__ __volatile__ (
"1: ldsw [%2], %0\n"
" brlz,a,pn %0, 2f\n"
" mov 0, %0\n"
" add %0, 1, %1\n"
" cas [%2], %0, %1\n"
" cmp %0, %1\n"
" membar #StoreLoad | #StoreStore\n"
" bne,pn %%icc, 1b\n"
" mov 1, %0\n"
"2:"
: "=&r" (tmp1), "=&r" (tmp2)
: "r" (lock)
: "memory");
return tmp1;
}
static void inline __read_unlock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
@ -211,12 +233,12 @@ static int inline __write_trylock(raw_rwlock_t *lock)
}
#define __raw_read_lock(p) __read_lock(p)
#define __raw_read_trylock(p) __read_trylock(p)
#define __raw_read_unlock(p) __read_unlock(p)
#define __raw_write_lock(p) __write_lock(p)
#define __raw_write_unlock(p) __write_unlock(p)
#define __raw_write_trylock(p) __write_trylock(p)
#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
#define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
#define __raw_write_can_lock(rw) (!(rw)->lock)