From patchwork Fri May 19 10:21:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13248183 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8822C7EE32 for ; Fri, 19 May 2023 10:34:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232095AbjESKer (ORCPT ); Fri, 19 May 2023 06:34:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231954AbjESKeU (ORCPT ); Fri, 19 May 2023 06:34:20 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B6E110E0; Fri, 19 May 2023 03:34:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=YB2UOIFIw2gwCNTVh1j30XHP2RZzZzmzkIRobxbOGl0=; b=ghSSZdzkafHz78mzS4GGbj71O7 SXXaHp+mpN010O+0jF+6pvvZGjzNbCeL9fRihXGCSrCvKmjJFi1w7JR/UVVTMMEXVA1Xnrdzu7+sB CpSLRVsXbmqoKQ1sJACrj4KY/PgWjUhWPBWqCcijzl6OImzKJISzAOd8sciG4X41lrr6zgoUpIKap paqHTBLRhlA/vM1uMKEqMUzfJCW+NvPNQOZMfIzoFLPznYjoSv44/83tGcfCgLWSn9Qwm8ElMANui kt8AgiykeY0kez68CgoqtGvGH1RwAJFfF20uQNpp87aEng/rdSek17PDz3oqM71sIF9yg35f2qVeS RZbT/x4Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pzxPv-006UqP-M2; Fri, 19 May 2023 10:33:00 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 109C630611B; Fri, 19 May 2023 12:32:56 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C35A8235EF0A0; Fri, 19 May 2023 12:32:55 +0200 (CEST) Message-ID: <20230519102715.502547082@infradead.org> User-Agent: quilt/0.66 Date: Fri, 19 May 2023 12:21:03 +0200 From: Peter Zijlstra To: bigeasy@linutronix.de Cc: mark.rutland@arm.com, maz@kernel.org, catalin.marinas@arm.com, will@kernel.org, chenhuacai@kernel.org, kernel@xen0n.name, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, pbonzini@redhat.com, wanpengli@tencent.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, jgross@suse.com, boris.ostrovsky@oracle.com, daniel.lezcano@linaro.org, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, rafael@kernel.org, peterz@infradead.org, longman@redhat.com, boqun.feng@gmail.com, pmladek@suse.com, senozhatsky@chromium.org, rostedt@goodmis.org, john.ogness@linutronix.de, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jstultz@google.com, sboyd@kernel.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v2 05/13] loongarch: Provide noinstr sched_clock_read() References: <20230519102058.581557770@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_read() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. Signed-off-by: Peter Zijlstra (Intel) --- arch/loongarch/include/asm/loongarch.h | 2 +- arch/loongarch/kernel/time.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/arch/loongarch/include/asm/loongarch.h +++ b/arch/loongarch/include/asm/loongarch.h @@ -1167,7 +1167,7 @@ static __always_inline void iocsr_write6 #ifndef __ASSEMBLY__ -static inline u64 drdtime(void) +static __always_inline u64 drdtime(void) { int rID = 0; u64 val = 0; --- a/arch/loongarch/kernel/time.c +++ b/arch/loongarch/kernel/time.c @@ -190,9 +190,9 @@ static u64 read_const_counter(struct clo return drdtime(); } -static u64 native_sched_clock(void) +static noinstr u64 sched_clock_read(void) { - return read_const_counter(NULL); + return drdtime(); } static struct clocksource clocksource_const = { @@ -211,7 +211,7 @@ int __init constant_clocksource_init(voi res = clocksource_register_hz(&clocksource_const, freq); - sched_clock_register(native_sched_clock, 64, freq); + sched_clock_register(sched_clock_read, 64, freq); pr_info("Constant clock source device register\n");