From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756791Ab0EXUby (ORCPT ); Mon, 24 May 2010 16:31:54 -0400 Received: from smtp-out.google.com ([74.125.121.35]:52577 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754693Ab0EXUbv (ORCPT ); Mon, 24 May 2010 16:31:51 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to: references:x-system-of-record; b=oAGUIWuTNjZOgYB7Gfa9c2/038aTjmRKA3h7dbO5vxO28kGcgHltZXqxgK9KTNHI8 IVt8Q/z5TyLZaJG/YyuUw== From: Michel Lespinasse To: Linus Torvalds , David Howells , Ingo Molnar , Thomas Gleixner Cc: LKML , Andrew Morton , Mike Waychison , Suleiman Souhlal , Ying Han Subject: [PATCH 02/11] x86 rwsem: minor cleanups Date: Mon, 24 May 2010 13:31:12 -0700 Message-Id: <1274733081-4623-3-git-send-email-walken@google.com> X-Mailer: git-send-email 1.7.0.1 In-Reply-To: <1274733081-4623-1-git-send-email-walken@google.com> References: <1274733081-4623-1-git-send-email-walken@google.com> X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Clarified few comments and made initialization of %edx/%rdx more uniform accross __down_write_nested, __up_read and __up_write functions. Signed-off-by: Michel Lespinasse Acked-by: David Howells --- arch/x86/include/asm/rwsem.h | 16 +++++++--------- 1 files changed, 7 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 3fd1ed3..0892acc 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -118,7 +118,7 @@ static inline void __down_read(struct rw_semaphore *sem) { asm volatile("# beginning down_read\n\t" LOCK_PREFIX _ASM_INC "(%1)\n\t" - /* adds 0x00000001, returns the old value */ + /* adds 0x00000001 */ " jns 1f\n" " call call_rwsem_down_read_failed\n" "1:\n\t" @@ -156,11 +156,9 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) { rwsem_count_t tmp; - - tmp = RWSEM_ACTIVE_WRITE_BIAS; asm volatile("# beginning down_write\n\t" LOCK_PREFIX " xadd %1,(%2)\n\t" - /* subtract 0x0000ffff, returns the old value */ + /* adds 0xffff0001, returns the old value */ " test %1,%1\n\t" /* was the count 0 before? */ " jz 1f\n" @@ -168,7 +166,7 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) "1:\n" "# ending down_write" : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (tmp) + : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) : "memory", "cc"); } @@ -195,16 +193,16 @@ static inline int __down_write_trylock(struct rw_semaphore *sem) */ static inline void __up_read(struct rw_semaphore *sem) { - rwsem_count_t tmp = -RWSEM_ACTIVE_READ_BIAS; + rwsem_count_t tmp; asm volatile("# beginning __up_read\n\t" LOCK_PREFIX " xadd %1,(%2)\n\t" /* subtracts 1, returns the old value */ " jns 1f\n\t" - " call call_rwsem_wake\n" + " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n" "# ending __up_read\n" : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (tmp) + : "a" (sem), "1" (-RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); } @@ -218,7 +216,7 @@ static inline void __up_write(struct rw_semaphore *sem) LOCK_PREFIX " xadd %1,(%2)\n\t" /* substracts 0xffff0001, returns the old value */ " jns 1f\n\t" - " call call_rwsem_wake\n" + " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n\t" "# ending __up_write\n" : "+m" (sem->count), "=d" (tmp) -- 1.7.0.1