From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755326Ab1GVT4S (ORCPT ); Fri, 22 Jul 2011 15:56:18 -0400 Received: from hera.kernel.org ([140.211.167.34]:38116 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755132Ab1GVT4Q (ORCPT ); Fri, 22 Jul 2011 15:56:16 -0400 Date: Fri, 22 Jul 2011 19:56:10 GMT From: tip-bot for Jeremy Fitzhardinge Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, hpa@linux.intel.com, jeremy.fitzhardinge@citrix.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@linux.intel.com, jeremy.fitzhardinge@citrix.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/spinlocks] x86, ticketlock: Use C for __ticket_spin_unlock Git-Commit-ID: 68302ae430d388a0118a8ce2a1abb5f87b737ef6 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 22 Jul 2011 19:56:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 68302ae430d388a0118a8ce2a1abb5f87b737ef6 Gitweb: http://git.kernel.org/tip/68302ae430d388a0118a8ce2a1abb5f87b737ef6 Author: Jeremy Fitzhardinge AuthorDate: Thu, 23 Jun 2011 18:19:15 -0700 Committer: H. Peter Anvin CommitDate: Fri, 22 Jul 2011 11:13:44 -0700 x86, ticketlock: Use C for __ticket_spin_unlock If we don't need to use a locked inc for unlock, then implement it in C. Signed-off-by: Jeremy Fitzhardinge Link: http://lkml.kernel.org/r/aa0d82c6e7a1c22a941da0df3c4ba58fea375074.1308878118.git.jeremy.fitzhardinge@citrix.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/spinlock.h | 33 ++++++++++++++++++--------------- 1 files changed, 18 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index f48a6e3..704b0c3 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -33,9 +33,21 @@ * On PPro SMP or if we are using OOSTORE, we use a locked operation to unlock * (PPro errata 66, 92) */ -# define UNLOCK_LOCK_PREFIX LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + if (sizeof(lock->tickets.head) == sizeof(u8)) + asm (LOCK_PREFIX "incb %0" + : "+m" (lock->tickets.head) : : "memory"); + else + asm (LOCK_PREFIX "incw %0" + : "+m" (lock->tickets.head) : : "memory"); + +} #else -# define UNLOCK_LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + lock->tickets.head++; +} #endif /* @@ -93,14 +105,6 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } - -static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) -{ - asm volatile(UNLOCK_LOCK_PREFIX "incb %0" - : "+m" (lock->slock) - : - : "memory", "cc"); -} #else static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) { @@ -144,15 +148,14 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } +#endif static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) { - asm volatile(UNLOCK_LOCK_PREFIX "incw %0" - : "+m" (lock->slock) - : - : "memory", "cc"); + barrier(); /* prevent reordering out of locked region */ + __ticket_unlock_release(lock); + barrier(); /* prevent reordering into locked region */ } -#endif static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) {