From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752438AbdF3ABw (ORCPT ); Thu, 29 Jun 2017 20:01:52 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43990 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751687AbdF3ABn (ORCPT ); Thu, 29 Jun 2017 20:01:43 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, oleg@redhat.com, akpm@linux-foundation.org, mingo@redhat.com, dave@stgolabs.net, manfred@colorfullife.com, tj@kernel.org, arnd@arndb.de, linux-arch@vger.kernel.org, will.deacon@arm.com, peterz@infradead.org, stern@rowland.harvard.edu, parri.andrea@gmail.com, torvalds@linux-foundation.org, "Paul E. McKenney" , Chris Metcalf Subject: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions Date: Thu, 29 Jun 2017 17:01:33 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20170629235918.GA6445@linux.vnet.ibm.com> References: <20170629235918.GA6445@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17063000-0024-0000-0000-000002A2D297 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007295; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00880606; UDB=6.00439011; IPR=6.00660759; BA=6.00005447; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016015; XFM=3.00000015; UTC=2017-06-30 00:01:41 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17063000-0025-0000-0000-000044943400 Message-Id: <1498780894-8253-25-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-29_17:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706290384 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is no agreed-upon definition of spin_unlock_wait()'s semantics, and it appears that all callers could do just as well with a lock/unlock pair. This commit therefore removes the underlying arch-specific arch_spin_unlock_wait(). Signed-off-by: Paul E. McKenney Cc: Chris Metcalf Cc: Will Deacon Cc: Peter Zijlstra Cc: Alan Stern Cc: Andrea Parri Cc: Linus Torvalds --- arch/tile/include/asm/spinlock_32.h | 2 -- arch/tile/include/asm/spinlock_64.h | 2 -- arch/tile/lib/spinlock_32.c | 23 ----------------------- arch/tile/lib/spinlock_64.c | 22 ---------------------- 4 files changed, 49 deletions(-) diff --git a/arch/tile/include/asm/spinlock_32.h b/arch/tile/include/asm/spinlock_32.h index b14b1ba5bf9c..cba8ba9b8da6 100644 --- a/arch/tile/include/asm/spinlock_32.h +++ b/arch/tile/include/asm/spinlock_32.h @@ -64,8 +64,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) lock->current_ticket = old_ticket + TICKET_QUANTUM; } -void arch_spin_unlock_wait(arch_spinlock_t *lock); - /* * Read-write spinlocks, allowing multiple readers * but only one writer. diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h index b9718fb4e74a..9a2c2d605752 100644 --- a/arch/tile/include/asm/spinlock_64.h +++ b/arch/tile/include/asm/spinlock_64.h @@ -58,8 +58,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) __insn_fetchadd4(&lock->lock, 1U << __ARCH_SPIN_CURRENT_SHIFT); } -void arch_spin_unlock_wait(arch_spinlock_t *lock); - void arch_spin_lock_slow(arch_spinlock_t *lock, u32 val); /* Grab the "next" ticket number and bump it atomically. diff --git a/arch/tile/lib/spinlock_32.c b/arch/tile/lib/spinlock_32.c index 076c6cc43113..db9333f2447c 100644 --- a/arch/tile/lib/spinlock_32.c +++ b/arch/tile/lib/spinlock_32.c @@ -62,29 +62,6 @@ int arch_spin_trylock(arch_spinlock_t *lock) } EXPORT_SYMBOL(arch_spin_trylock); -void arch_spin_unlock_wait(arch_spinlock_t *lock) -{ - u32 iterations = 0; - int curr = READ_ONCE(lock->current_ticket); - int next = READ_ONCE(lock->next_ticket); - - /* Return immediately if unlocked. */ - if (next == curr) - return; - - /* Wait until the current locker has released the lock. */ - do { - delay_backoff(iterations++); - } while (READ_ONCE(lock->current_ticket) == curr); - - /* - * The TILE architecture doesn't do read speculation; therefore - * a control dependency guarantees a LOAD->{LOAD,STORE} order. - */ - barrier(); -} -EXPORT_SYMBOL(arch_spin_unlock_wait); - /* * The low byte is always reserved to be the marker for a "tns" operation * since the low bit is set to "1" by a tns. The next seven bits are diff --git a/arch/tile/lib/spinlock_64.c b/arch/tile/lib/spinlock_64.c index a4b5b2cbce93..de414c22892f 100644 --- a/arch/tile/lib/spinlock_64.c +++ b/arch/tile/lib/spinlock_64.c @@ -62,28 +62,6 @@ int arch_spin_trylock(arch_spinlock_t *lock) } EXPORT_SYMBOL(arch_spin_trylock); -void arch_spin_unlock_wait(arch_spinlock_t *lock) -{ - u32 iterations = 0; - u32 val = READ_ONCE(lock->lock); - u32 curr = arch_spin_current(val); - - /* Return immediately if unlocked. */ - if (arch_spin_next(val) == curr) - return; - - /* Wait until the current locker has released the lock. */ - do { - delay_backoff(iterations++); - } while (arch_spin_current(READ_ONCE(lock->lock)) == curr); - - /* - * The TILE architecture doesn't do read speculation; therefore - * a control dependency guarantees a LOAD->{LOAD,STORE} order. - */ - barrier(); -} -EXPORT_SYMBOL(arch_spin_unlock_wait); /* * If the read lock fails due to a writer, we retry periodically -- 2.5.2