From 4db2ce0199f04b6e99999f22e28ef9a0ae5f0d2f Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 14 Sep 2005 21:47:01 -0700 Subject: [LIB]: Consolidate _atomic_dec_and_lock() Several implementations were essentialy a common piece of C code using the cmpxchg() macro. Put the implementation in one spot that everyone can share, and convert sparc64 over to using this. Alpha is the lone arch-specific implementation, which codes up a special fast path for the common case in order to avoid GP reloading which a pure C version would require. Signed-off-by: David S. Miller --- arch/x86_64/lib/Makefile | 2 -- arch/x86_64/lib/dec_and_lock.c | 40 ---------------------------------------- 2 files changed, 42 deletions(-) delete mode 100644 arch/x86_64/lib/dec_and_lock.c (limited to 'arch/x86_64/lib') diff --git a/arch/x86_64/lib/Makefile b/arch/x86_64/lib/Makefile index 6b26a1c1e9f..bba5db6cebd 100644 --- a/arch/x86_64/lib/Makefile +++ b/arch/x86_64/lib/Makefile @@ -10,5 +10,3 @@ lib-y := csum-partial.o csum-copy.o csum-wrappers.o delay.o \ usercopy.o getuser.o putuser.o \ thunk.o clear_page.o copy_page.o bitstr.o bitops.o lib-y += memcpy.o memmove.o memset.o copy_user.o - -lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o diff --git a/arch/x86_64/lib/dec_and_lock.c b/arch/x86_64/lib/dec_and_lock.c deleted file mode 100644 index ab43394dc77..00000000000 --- a/arch/x86_64/lib/dec_and_lock.c +++ /dev/null @@ -1,40 +0,0 @@ -/* - * x86 version of "atomic_dec_and_lock()" using - * the atomic "cmpxchg" instruction. - * - * (For CPU's lacking cmpxchg, we use the slow - * generic version, and this one never even gets - * compiled). - */ - -#include -#include - -int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) -{ - int counter; - int newcount; - -repeat: - counter = atomic_read(atomic); - newcount = counter-1; - - if (!newcount) - goto slow_path; - - asm volatile("lock; cmpxchgl %1,%2" - :"=a" (newcount) - :"r" (newcount), "m" (atomic->counter), "0" (counter)); - - /* If the above failed, "eax" will have changed */ - if (newcount != counter) - goto repeat; - return 0; - -slow_path: - spin_lock(lock); - if (atomic_dec_and_test(atomic)) - return 1; - spin_unlock(lock); - return 0; -} -- cgit v1.2.3