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/ppc64/lib/Makefile | 2 +- arch/ppc64/lib/dec_and_lock.c | 47 ------------------------------------------- 2 files changed, 1 insertion(+), 48 deletions(-) delete mode 100644 arch/ppc64/lib/dec_and_lock.c (limited to 'arch/ppc64/lib') diff --git a/arch/ppc64/lib/Makefile b/arch/ppc64/lib/Makefile index 76fbfa9f706f..0b6e967de948 100644 --- a/arch/ppc64/lib/Makefile +++ b/arch/ppc64/lib/Makefile @@ -2,7 +2,7 @@ # Makefile for ppc64-specific library files.. # -lib-y := checksum.o dec_and_lock.o string.o strcase.o +lib-y := checksum.o string.o strcase.o lib-y += copypage.o memcpy.o copyuser.o usercopy.o # Lock primitives are defined as no-ops in include/linux/spinlock.h diff --git a/arch/ppc64/lib/dec_and_lock.c b/arch/ppc64/lib/dec_and_lock.c deleted file mode 100644 index 7b9d4da5cf92..000000000000 --- a/arch/ppc64/lib/dec_and_lock.c +++ /dev/null @@ -1,47 +0,0 @@ -/* - * ppc64 version of atomic_dec_and_lock() using cmpxchg - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include -#include -#include -#include - -/* - * This is an implementation of the notion of "decrement a - * reference count, and return locked if it decremented to zero". - * - * This implementation can be used on any architecture that - * has a cmpxchg, and where atomic->value is an int holding - * the value of the atomic (i.e. the high bits aren't used - * for a lock or anything like that). - */ -int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) -{ - int counter; - int newcount; - - for (;;) { - counter = atomic_read(atomic); - newcount = counter - 1; - if (!newcount) - break; /* do it the slow way */ - - newcount = cmpxchg(&atomic->counter, counter, newcount); - if (newcount == counter) - return 0; - } - - spin_lock(lock); - if (atomic_dec_and_test(atomic)) - return 1; - spin_unlock(lock); - return 0; -} - -EXPORT_SYMBOL(_atomic_dec_and_lock); -- cgit v1.2.3-59-g8ed1b