From patchwork Tue May 17 07:49:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: xinhui X-Patchwork-Id: 622951 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3r88qY3BV5z9sBG for ; Tue, 17 May 2016 17:59:21 +1000 (AEST) Received: from ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3r88qY2Q4LzDqcH for ; Tue, 17 May 2016 17:59:21 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [125.16.236.5]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r88f93PGtzDqBZ for ; Tue, 17 May 2016 17:51:13 +1000 (AEST) Received: from localhost by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 17 May 2016 13:21:03 +0530 X-IBM-Helo: d28dlp03.in.ibm.com X-IBM-MailFrom: xinhui.pan@linux.vnet.ibm.com X-IBM-RcptTo: linuxppc-dev@lists.ozlabs.org Received: from d28relay06.in.ibm.com (d28relay06.in.ibm.com [9.184.220.150]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id C88EA125804F for ; Tue, 17 May 2016 13:23:12 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay06.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4H7p0HW44892334 for ; Tue, 17 May 2016 13:21:00 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4H7oqct017845 for ; Tue, 17 May 2016 13:20:59 +0530 Received: from pp-VirtualBox.cn.ibm.com (adminib-8ad6lrj.cn.ibm.com [9.123.229.170]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u4H7oRM8016392; Tue, 17 May 2016 13:20:49 +0530 From: Pan Xinhui To: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2 3/6] powerpc: lib/locks.c: cpu yield/wake helper function Date: Tue, 17 May 2016 15:49:44 +0800 Message-Id: <1463471387-5115-4-git-send-email-xinhui.pan@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1463471387-5115-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> References: <1463471387-5115-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16051707-0017-0000-0000-00001EE350D2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mnipxh@163.com, Pan Xinhui , peterz@infradead.org, boqun.feng@gmail.com, waiman.long@hpe.com, mingo@redhat.com, paulus@samba.org, paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" pv-qspinlock core has pv_wait/pv_kick which will give a better performace by yielding and kicking cpu at some cases. lets support them by adding two corresponding helper functions. Signed-off-by: Pan Xinhui --- arch/powerpc/include/asm/spinlock.h | 4 ++++ arch/powerpc/lib/locks.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h index 4359ee6..3b65372 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -56,9 +56,13 @@ /* We only yield to the hypervisor if we are in shared processor mode */ #define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr)) extern void __spin_yield(arch_spinlock_t *lock); +extern void __spin_yield_cpu(int cpu); +extern void __spin_wake_cpu(int cpu); extern void __rw_yield(arch_rwlock_t *lock); #else /* SPLPAR */ #define __spin_yield(x) barrier() +#define __spin_yield_cpu(x) barrier() +#define __spin_wake_cpu(x) barrier() #define __rw_yield(x) barrier() #define SHARED_PROCESSOR 0 #endif diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c index a9ebd71..4109679a 100644 --- a/arch/powerpc/lib/locks.c +++ b/arch/powerpc/lib/locks.c @@ -23,6 +23,38 @@ #include #include +void __spin_yield_cpu(int cpu) +{ + unsigned int holder_cpu = cpu, yield_count; + + if (cpu == -1) { + plpar_hcall_norets(H_CEDE); + return; + } + BUG_ON(holder_cpu >= nr_cpu_ids); + yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count); + if ((yield_count & 1) == 0) + return; /* virtual cpu is currently running */ + rmb(); + plpar_hcall_norets(H_CONFER, + get_hard_smp_processor_id(holder_cpu), yield_count); +} +EXPORT_SYMBOL_GPL(__spin_yield_cpu); + +void __spin_wake_cpu(int cpu) +{ + unsigned int holder_cpu = cpu, yield_count; + + BUG_ON(holder_cpu >= nr_cpu_ids); + yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count); + if ((yield_count & 1) == 0) + return; /* virtual cpu is currently running */ + rmb(); + plpar_hcall_norets(H_PROD, + get_hard_smp_processor_id(holder_cpu)); +} +EXPORT_SYMBOL_GPL(__spin_wake_cpu); + #ifndef CONFIG_QUEUED_SPINLOCKS void __spin_yield(arch_spinlock_t *lock) {