From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFED8C433EF for ; Fri, 19 Nov 2021 10:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A729761B6F for ; Fri, 19 Nov 2021 10:21:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234605AbhKSKYu (ORCPT ); Fri, 19 Nov 2021 05:24:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59032 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233172AbhKSKYt (ORCPT ); Fri, 19 Nov 2021 05:24:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637317307; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mX5jcuznSuqa2Xcuiv4jYmRlfngakhSaRM4ITDtNgjs=; b=TOOuGwIm594LaVJWHWYVb3yhor7CWbv0EuApMXuLE7yp6/D4BAkeOB41S/03/kUuVq5LSL 2mEltvPYM9p0401nPPbgARtMw1/NiALyVppv9M+faZc/QeJ3Yga1fnl0mV5btXW/UaGadF T0DCvm+9UCWBJMMbTwnpZSZkZRPatyU= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-525-u67RsU1KMCeWjsFSAdou7A-1; Fri, 19 Nov 2021 05:21:45 -0500 X-MC-Unique: u67RsU1KMCeWjsFSAdou7A-1 Received: by mail-wm1-f70.google.com with SMTP id v10-20020a1cf70a000000b00318203a6bd1so4510814wmh.6 for ; Fri, 19 Nov 2021 02:21:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=mX5jcuznSuqa2Xcuiv4jYmRlfngakhSaRM4ITDtNgjs=; b=PfYq/eVTtr20PsQqm0wmV6A1LSWbBrXvDCwPN6eTwlq11wDXW05Mwf6bErBcc5FUFw Ibe4G+wAmJz9yge8ntbQVGgGX0an9CSpde/v2gmjkrcz6d8cxoS24WDJtHWeiY5EuGM2 f7iPzhUVJhpM359YL4jvP6rlKTFN1SbO7PxDdt9riQHAdF/ZRh93mvkYUDXN52WTOBfz 6BSCjOzNvOCS9q/TptlXFiJQMmOolo+BMR5L3PhmFnzvbJagqCELbA7SD8btq+aaAGqT cKRkP+62aOpQCxoK6JzUWJtcHmcyFsMz/famZTXk2k6ZXPgS08MmA6EmbJJXWPAbx992 xoMA== X-Gm-Message-State: AOAM531RK01uLWAh2iWWSLPbPhOYAVtgjCQopqQjRS++Js2ZHaLkx0cQ 5yhSegvo6+fIZ/ePvzgmd4XfNQXIVQUdbTfo8MeK4TENnfvh3S1MFdhmp2f4QCi0PYrfKbVf/ek qygQZSGRHqzror6WL8c8GkNSD X-Received: by 2002:a5d:4909:: with SMTP id x9mr5932212wrq.313.1637317304296; Fri, 19 Nov 2021 02:21:44 -0800 (PST) X-Google-Smtp-Source: ABdhPJxeQnWOxgbNOebQdl80w1DTmX2lRjG3ogVnSnid0ngmyFfrhWmSZI2Hfqqy5HB4Ucb0MKfToQ== X-Received: by 2002:a5d:4909:: with SMTP id x9mr5932181wrq.313.1637317304102; Fri, 19 Nov 2021 02:21:44 -0800 (PST) Received: from vian.redhat.com ([2a0c:5a80:3c10:3400:3c70:6643:6e71:7eae]) by smtp.gmail.com with ESMTPSA id k27sm14336026wms.41.2021.11.19.02.21.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Nov 2021 02:21:43 -0800 (PST) From: Nicolas Saenz Julienne To: linux-arm-kernel@lists.infradead.org, maz@kernel.org, rostedt@goodmis.org Cc: james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, nsaenzju@redhat.com, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, mingo@redhat.com, mtosatti@redhat.com, nilal@redhat.com Subject: [RFC PATCH 1/2] arm64/tracing: add cntvct based trace clock Date: Fri, 19 Nov 2021 11:21:17 +0100 Message-Id: <20211119102117.22304-2-nsaenzju@redhat.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211119102117.22304-1-nsaenzju@redhat.com> References: <20211119102117.22304-1-nsaenzju@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a new arm64-specific trace clock using the cntvct register, similar to x64-tsc. This gives us: - A clock that is relatively fast (1GHz on armv8.6, 1-50MHz otherwise), monotonic, and resilient to low power modes. - It can be used to correlate events across cpus as well as across hypervisor and guests. By using arch_timer_read_counter() we make sure that armv8.6 cpus use the less expensive CNTVCTSS_EL0, which cannot be accessed speculatively. Signed-off-by: Nicolas Saenz Julienne --- arch/arm64/include/asm/trace_clock.h | 12 ++++++++++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/trace_clock.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/trace_clock.h create mode 100644 arch/arm64/kernel/trace_clock.c diff --git a/arch/arm64/include/asm/trace_clock.h b/arch/arm64/include/asm/trace_clock.h new file mode 100644 index 000000000000..ce4a66d63108 --- /dev/null +++ b/arch/arm64/include/asm/trace_clock.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM64_TRACE_CLOCK_H +#define _ASM_ARM64_TRACE_CLOCK_H + +#include + +extern u64 notrace trace_clock_arm64_cntvct(void); + +# define ARCH_TRACE_CLOCKS \ + { trace_clock_arm64_cntvct, "cntvct", .in_ns = 0 }, + +#endif /* _ASM_ARM64_TRACE_CLOCK_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 88b3e2a21408..ec9180f0ac90 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -29,7 +29,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ cpufeature.o alternative.o cacheinfo.o \ smp.o smp_spin_table.o topology.o smccc-call.o \ syscall.o proton-pack.o idreg-override.o idle.o \ - patching.o + patching.o trace_clock.o targets += efi-entry.o diff --git a/arch/arm64/kernel/trace_clock.c b/arch/arm64/kernel/trace_clock.c new file mode 100644 index 000000000000..fe1315f368cb --- /dev/null +++ b/arch/arm64/kernel/trace_clock.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * arm64 trace clocks + */ +#include + +#include + +u64 notrace trace_clock_arm64_cntvct(void) +{ + return arch_timer_read_counter(); 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Fri, 19 Nov 2021 02:21:44 -0800 (PST) X-Google-Smtp-Source: ABdhPJxeQnWOxgbNOebQdl80w1DTmX2lRjG3ogVnSnid0ngmyFfrhWmSZI2Hfqqy5HB4Ucb0MKfToQ== X-Received: by 2002:a5d:4909:: with SMTP id x9mr5932181wrq.313.1637317304102; Fri, 19 Nov 2021 02:21:44 -0800 (PST) Received: from vian.redhat.com ([2a0c:5a80:3c10:3400:3c70:6643:6e71:7eae]) by smtp.gmail.com with ESMTPSA id k27sm14336026wms.41.2021.11.19.02.21.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Nov 2021 02:21:43 -0800 (PST) From: Nicolas Saenz Julienne To: linux-arm-kernel@lists.infradead.org, maz@kernel.org, rostedt@goodmis.org Cc: james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, nsaenzju@redhat.com, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, mingo@redhat.com, mtosatti@redhat.com, nilal@redhat.com Subject: [RFC PATCH 1/2] arm64/tracing: add cntvct based trace clock Date: Fri, 19 Nov 2021 11:21:17 +0100 Message-Id: <20211119102117.22304-2-nsaenzju@redhat.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211119102117.22304-1-nsaenzju@redhat.com> References: <20211119102117.22304-1-nsaenzju@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=nsaenzju@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211119_022149_920589_D8718647 X-CRM114-Status: GOOD ( 16.50 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add a new arm64-specific trace clock using the cntvct register, similar to x64-tsc. This gives us: - A clock that is relatively fast (1GHz on armv8.6, 1-50MHz otherwise), monotonic, and resilient to low power modes. - It can be used to correlate events across cpus as well as across hypervisor and guests. By using arch_timer_read_counter() we make sure that armv8.6 cpus use the less expensive CNTVCTSS_EL0, which cannot be accessed speculatively. Signed-off-by: Nicolas Saenz Julienne --- arch/arm64/include/asm/trace_clock.h | 12 ++++++++++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/trace_clock.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/trace_clock.h create mode 100644 arch/arm64/kernel/trace_clock.c diff --git a/arch/arm64/include/asm/trace_clock.h b/arch/arm64/include/asm/trace_clock.h new file mode 100644 index 000000000000..ce4a66d63108 --- /dev/null +++ b/arch/arm64/include/asm/trace_clock.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM64_TRACE_CLOCK_H +#define _ASM_ARM64_TRACE_CLOCK_H + +#include + +extern u64 notrace trace_clock_arm64_cntvct(void); + +# define ARCH_TRACE_CLOCKS \ + { trace_clock_arm64_cntvct, "cntvct", .in_ns = 0 }, + +#endif /* _ASM_ARM64_TRACE_CLOCK_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 88b3e2a21408..ec9180f0ac90 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -29,7 +29,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ cpufeature.o alternative.o cacheinfo.o \ smp.o smp_spin_table.o topology.o smccc-call.o \ syscall.o proton-pack.o idreg-override.o idle.o \ - patching.o + patching.o trace_clock.o targets += efi-entry.o diff --git a/arch/arm64/kernel/trace_clock.c b/arch/arm64/kernel/trace_clock.c new file mode 100644 index 000000000000..fe1315f368cb --- /dev/null +++ b/arch/arm64/kernel/trace_clock.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * arm64 trace clocks + */ +#include + +#include + +u64 notrace trace_clock_arm64_cntvct(void) +{ + return arch_timer_read_counter(); +} -- 2.33.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88E2AC433EF for ; Fri, 19 Nov 2021 12:29:36 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 2682261AD0 for ; Fri, 19 Nov 2021 12:29:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2682261AD0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id BBE344B17C; 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Fri, 19 Nov 2021 02:21:44 -0800 (PST) Received: from vian.redhat.com ([2a0c:5a80:3c10:3400:3c70:6643:6e71:7eae]) by smtp.gmail.com with ESMTPSA id k27sm14336026wms.41.2021.11.19.02.21.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Nov 2021 02:21:43 -0800 (PST) From: Nicolas Saenz Julienne To: linux-arm-kernel@lists.infradead.org, maz@kernel.org, rostedt@goodmis.org Subject: [RFC PATCH 1/2] arm64/tracing: add cntvct based trace clock Date: Fri, 19 Nov 2021 11:21:17 +0100 Message-Id: <20211119102117.22304-2-nsaenzju@redhat.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211119102117.22304-1-nsaenzju@redhat.com> References: <20211119102117.22304-1-nsaenzju@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=nsaenzju@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Mailman-Approved-At: Fri, 19 Nov 2021 07:29:31 -0500 Cc: will@kernel.org, catalin.marinas@arm.com, mtosatti@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, nsaenzju@redhat.com, nilal@redhat.com, kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Add a new arm64-specific trace clock using the cntvct register, similar to x64-tsc. This gives us: - A clock that is relatively fast (1GHz on armv8.6, 1-50MHz otherwise), monotonic, and resilient to low power modes. - It can be used to correlate events across cpus as well as across hypervisor and guests. By using arch_timer_read_counter() we make sure that armv8.6 cpus use the less expensive CNTVCTSS_EL0, which cannot be accessed speculatively. Signed-off-by: Nicolas Saenz Julienne --- arch/arm64/include/asm/trace_clock.h | 12 ++++++++++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/trace_clock.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/trace_clock.h create mode 100644 arch/arm64/kernel/trace_clock.c diff --git a/arch/arm64/include/asm/trace_clock.h b/arch/arm64/include/asm/trace_clock.h new file mode 100644 index 000000000000..ce4a66d63108 --- /dev/null +++ b/arch/arm64/include/asm/trace_clock.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM64_TRACE_CLOCK_H +#define _ASM_ARM64_TRACE_CLOCK_H + +#include + +extern u64 notrace trace_clock_arm64_cntvct(void); + +# define ARCH_TRACE_CLOCKS \ + { trace_clock_arm64_cntvct, "cntvct", .in_ns = 0 }, + +#endif /* _ASM_ARM64_TRACE_CLOCK_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 88b3e2a21408..ec9180f0ac90 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -29,7 +29,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ cpufeature.o alternative.o cacheinfo.o \ smp.o smp_spin_table.o topology.o smccc-call.o \ syscall.o proton-pack.o idreg-override.o idle.o \ - patching.o + patching.o trace_clock.o targets += efi-entry.o diff --git a/arch/arm64/kernel/trace_clock.c b/arch/arm64/kernel/trace_clock.c new file mode 100644 index 000000000000..fe1315f368cb --- /dev/null +++ b/arch/arm64/kernel/trace_clock.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * arm64 trace clocks + */ +#include + +#include + +u64 notrace trace_clock_arm64_cntvct(void) +{ + return arch_timer_read_counter(); +} -- 2.33.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm