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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/alpha/lib/dec_and_lock.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/alpha/lib/dec_and_lock.c')
-rw-r--r-- | arch/alpha/lib/dec_and_lock.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/alpha/lib/dec_and_lock.c b/arch/alpha/lib/dec_and_lock.c new file mode 100644 index 0000000..6ae2500 --- /dev/null +++ b/arch/alpha/lib/dec_and_lock.c @@ -0,0 +1,42 @@ +/* + * arch/alpha/lib/dec_and_lock.c + * + * ll/sc version of atomic_dec_and_lock() + * + */ + +#include <linux/spinlock.h> +#include <asm/atomic.h> + + asm (".text \n\ + .global _atomic_dec_and_lock \n\ + .ent _atomic_dec_and_lock \n\ + .align 4 \n\ +_atomic_dec_and_lock: \n\ + .prologue 0 \n\ +1: ldl_l $1, 0($16) \n\ + subl $1, 1, $1 \n\ + beq $1, 2f \n\ + stl_c $1, 0($16) \n\ + beq $1, 4f \n\ + mb \n\ + clr $0 \n\ + ret \n\ +2: br $29, 3f \n\ +3: ldgp $29, 0($29) \n\ + br $atomic_dec_and_lock_1..ng \n\ + .subsection 2 \n\ +4: br 1b \n\ + .previous \n\ + .end _atomic_dec_and_lock"); + +static int __attribute_used__ +atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock) +{ + /* Slow path */ + spin_lock(lock); + if (atomic_dec_and_test(atomic)) + return 1; + spin_unlock(lock); + return 0; +} |