I just looked at Alpha's atomic_dec_and_lock assembly and did something that should work for atomic_dec_and_lock_irqsave. I think it works but I would prefer for someone from the Alpha-Camp to ack this before it goes in. It is not critical because the non-optimized version should work.
Cc: Richard Henderson <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Matt Turner <[email protected]> Cc: [email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- arch/alpha/lib/dec_and_lock.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/arch/alpha/lib/dec_and_lock.c b/arch/alpha/lib/dec_and_lock.c index 069fef7372dc..d29ba1de4f68 100644 --- a/arch/alpha/lib/dec_and_lock.c +++ b/arch/alpha/lib/dec_and_lock.c @@ -32,6 +32,28 @@ _atomic_dec_and_lock: \n\ .previous \n\ .end _atomic_dec_and_lock"); + asm (".text \n\ + .global _atomic_dec_and_lock_irqsave \n\ + .ent _atomic_dec_and_lock_irqsave \n\ + .align 4 \n\ +_atomic_dec_and_lock_irqsave: \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_irqsave1..ng \n\ + .subsection 2 \n\ +4: br 1b \n\ + .previous \n\ + .end _atomic_dec_and_lock_irqsave"); + static int __used atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock) { /* Slow path */ @@ -43,14 +65,11 @@ static int __used atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock) } EXPORT_SYMBOL(_atomic_dec_and_lock); -int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock, - unsigned long *flags) +static int __used atomic_dec_and_lock_irqsave1(atomic_t *atomic, + spinlock_t *lock, + unsigned long *flags) { - /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */ - if (atomic_add_unless(atomic, -1, 1)) - return 0; - - /* Otherwise do it the slow way */ + /* Slow way */ spin_lock_irqsave(lock, *flags); if (atomic_dec_and_test(atomic)) return 1; -- 2.17.1 -- To unsubscribe from this list: send the line "unsubscribe linux-alpha" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
