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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D70E3C4361B for ; Mon, 7 Dec 2020 16:01:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 930C423750 for ; Mon, 7 Dec 2020 16:01:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727059AbgLGQBe (ORCPT ); Mon, 7 Dec 2020 11:01:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725781AbgLGQBe (ORCPT ); Mon, 7 Dec 2020 11:01:34 -0500 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3060AC061749 for ; Mon, 7 Dec 2020 08:00:54 -0800 (PST) Received: by mail-pf1-x444.google.com with SMTP id i3so6833180pfd.6 for ; Mon, 07 Dec 2020 08:00:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=lM0WuLFezI4DgUVIv9tHFek9mZlL8JVIYtiPTuIe1i8=; b=kbfciW8e8c9iyJrhOcz17nhJT7qYBlGk+2u/n/iqhnv89bEa5UC9/Eg7M8JV0AHKtL P+22D6mGIRBKQ3E4jVWW+ee2L9iNRiie72mWT3+mnBdbz9J0GNy12tSn/FVTLErdtKSf exPhKr/Q13rphwK/XVwASyIhTDokUbrY2sY840Bqc8XgOrjOrik16SQclTjZ++wUBcqI amQPV+e2AInJbV+1S3arjvmuxun3mPpOVIA8AnuffExVIz7wFrTCL2lzMwHVZQbyBCV2 1QLLZfVHpzixCH4AXc79AYhtoTqDqYBOBNgW2Op2NzRn9xkbJATvm1ZVb0Hn5Xy09XBt 5EWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=lM0WuLFezI4DgUVIv9tHFek9mZlL8JVIYtiPTuIe1i8=; b=ICW4OgF2vdGpN4YlmKY/+0nxKTGxiq4WOOMBXQCgMXIVQGdMac8gKWfgFuSgrqamlj /i75nAxI4+AAnbF2OWg495pXSevq0ZLaincKTt8eioh0NEuNg8F5O+EDhP1ysPccWQFJ tnHRWYHQlKVTERiI95pVP9uhweDjpwHGwWSyKUJVwdlYly8ECecykxwQ/jwKIX7gs2Kv VbyWmsVUm8yN4TFuKXBJ2VSwAJWmCasn1U+3VlHAtvN5BhKSpVNwMpAoYIG0Lo9sWC+E /H747BdawM7V1cMmLVmluj7EwwvdPOgIRqgqKORDfpSXhOZu2xJZAlU83+5A/Lw0HcGU 0DVg== X-Gm-Message-State: AOAM530oD6319B7xZO7ZrhlK4ZEgsgvxp+OHWEOKd5HD65E7ZepLHLGZ VRjtNnsxSgJJJYYmQHYJqApPZQ== X-Google-Smtp-Source: ABdhPJyV4rYEnm55TXN93aP5Cqfz+sqaDms9fAkSfQdIJHYDMAGBBvylNH/P/lbMQZrVW+9O8adjjA== X-Received: by 2002:a62:b50f:0:b029:19e:2974:b7a4 with SMTP id y15-20020a62b50f0000b029019e2974b7a4mr3023076pfe.61.1607356853504; Mon, 07 Dec 2020 08:00:53 -0800 (PST) Received: from xps15 (S0106889e681aac74.cg.shawcable.net. [68.147.0.187]) by smtp.gmail.com with ESMTPSA id gm2sm11296944pjb.35.2020.12.07.08.00.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 08:00:52 -0800 (PST) Date: Mon, 7 Dec 2020 09:00:51 -0700 From: Mathieu Poirier To: Qi Liu Cc: Suzuki K Poulose , coresight@lists.linaro.org, linuxarm@huawei.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mike.leach@linaro.org Subject: Re: [PATCH v5] coresight: etm4x: Modify core-commit of cpu to avoid the overflow of HiSilicon ETM Message-ID: <20201207160051.GA1506562@xps15> References: <1606397670-15657-1-git-send-email-liuqi115@huawei.com> <20201204185551.GB1424711@xps15> <448eb009-da3e-b918-984d-cf563a64f31d@huawei.com> <07243eef-dbcf-6500-a66b-5c0e1689ece9@arm.com> <0e56f56e-157e-ecf2-bb21-74b79ffdf2ac@huawei.com> <6078c05c-273d-a9cb-6dcb-68009260a581@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6078c05c-273d-a9cb-6dcb-68009260a581@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 07, 2020 at 07:32:21PM +0800, Qi Liu wrote: > > > On 2020/12/7 19:27, Suzuki K Poulose wrote: > > On 12/7/20 11:21 AM, Qi Liu wrote: > >> > >> Hi Suzuki, > >> On 2020/12/7 18:38, Suzuki K Poulose wrote: > >>> On 12/7/20 2:08 AM, Qi Liu wrote: > >>>> Hi Mathieu, > >>>> > >>>> On 2020/12/5 2:55, Mathieu Poirier wrote: > >>>>> On Thu, Nov 26, 2020 at 09:34:30PM +0800, Qi Liu wrote: > >>>>>> The ETM device can't keep up with the core pipeline when cpu core > >>>>>> is at full speed. This may cause overflow within core and its ETM. > >>>>>> This is a common phenomenon on ETM devices. > >>>>>> > >>>>>> On HiSilicon Hip08 platform, a specific feature is added to set > >>>>>> core pipeline. So commit rate can be reduced manually to avoid ETM > >>>>>> overflow. > >>>>>> > >>>>>> Signed-off-by: Qi Liu > >>>>>> --- > >>>>>> Change since v1: > >>>>>> - add CONFIG_ETM4X_IMPDEF_FEATURE and CONFIG_ETM4X_IMPDEF_HISILICON > >>>>>> to keep specific feature off platforms which don't use it. > >>>>>> Change since v2: > >>>>>> - remove some unused variable. > >>>>>> Change since v3: > >>>>>> - use read/write_sysreg_s() to access register. > >>>>>> Change since v4: > >>>>>> - rename the call back function to a more generic name, and fix some > >>>>>> compile warnings. > >>>>>> > >>>>>> drivers/hwtracing/coresight/Kconfig | 9 +++ > >>>>>> drivers/hwtracing/coresight/coresight-etm4x-core.c | 88 ++++++++++++++++++++++ > >>>>>> drivers/hwtracing/coresight/coresight-etm4x.h | 8 ++ > >>>>>> 3 files changed, 105 insertions(+) > >>>>>> > >>>>>> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig > >>>>>> index c119824..1cc3601 100644 > >>>>>> --- a/drivers/hwtracing/coresight/Kconfig > >>>>>> +++ b/drivers/hwtracing/coresight/Kconfig > >>>>>> @@ -110,6 +110,15 @@ config CORESIGHT_SOURCE_ETM4X > >>>>>> To compile this driver as a module, choose M here: the > >>>>>> module will be called coresight-etm4x. > >>>>>> > >>>>>> +config ETM4X_IMPDEF_FEATURE > >>>>>> + bool "Control overflow impdef support in CoreSight ETM 4.x driver " > >>>>>> + depends on CORESIGHT_SOURCE_ETM4X > >>>>>> + help > >>>>>> + This control provides overflow implement define for CoreSight > >>>>>> + ETM 4.x tracer module which could not reduce commit race > >>>>>> + automatically, and could avoid overflow within ETM tracer module > >>>>>> + and its cpu core. > >>>>>> + > >>>>>> config CORESIGHT_STM > >>>>>> tristate "CoreSight System Trace Macrocell driver" > >>>>>> depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64 > >>>>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > >>>>>> index abd706b..fcee27a 100644 > >>>>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > >>>>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > >>>>>> @@ -3,6 +3,7 @@ > >>>>>> * Copyright (c) 2014, The Linux Foundation. All rights reserved. > >>>>>> */ > >>>>>> > >>>>>> +#include > >>>>>> #include > >>>>>> #include > >>>>>> #include > >>>>>> @@ -28,7 +29,9 @@ > >>>>>> #include > >>>>>> #include > >>>>>> #include > >>>>>> + > >>>>>> #include > >>>>>> +#include > >>>>>> #include > >>>>>> #include > >>>>>> > >>>>>> @@ -103,6 +106,87 @@ struct etm4_enable_arg { > >>>>>> int rc; > >>>>>> }; > >>>>>> > >>>>>> +#ifdef CONFIG_ETM4X_IMPDEF_FEATURE > >>>>>> + > >>>>>> +#define HISI_HIP08_AMBA_ID 0x000b6d01 > >>>>>> +#define ETM4_AMBA_MASK 0xfffff > >>>>>> +#define HISI_HIP08_CORE_COMMIT_CLEAR 0x3000 > >>>>> > >>>>> Here bit 12 and 13 are cleared but in etm4_hisi_config_core_commit() only bit 12 > >>>>> is set - is this intentional? What is bit 13 for? > >>>>> > >>>> bit 12 and 13 are used together to set core-commit, 2'b00 means cpu is at full speed, > >>>> 2'b01, 2'b10, 2'b11 means reduce the speed of cpu pipeline, and 2'b01 means speed is > >>>> reduced to minimum value. So bit 12 and 13 should be cleared together in > >>>> etm4_hisi_config_core_commit(). > >>> > >>> Please could you document this in the function. > >>> > >> of course, thanks. > >>>> > >>>> Qi > >>>> > >>>>>> +#define HISI_HIP08_CORE_COMMIT_SHIFT 12 > >>>>>> +#define HISI_HIP08_CORE_COMMIT_REG sys_reg(3, 1, 15, 2, 5) > >>>>>> + > >>>>>> +struct etm4_arch_features { > >>>>>> + void (*arch_callback)(bool enable); > >>>>>> +}; > >>>>>> + > >>>>>> +static bool etm4_hisi_match_pid(unsigned int id) > >>>>>> +{ > >>>>>> + return (id & ETM4_AMBA_MASK) == HISI_HIP08_AMBA_ID; > >>>>>> +} > >>>>>> + > >>>>>> +static void etm4_hisi_config_core_commit(bool enable) > >>>>>> +{ > >>>>>> + u64 val; > >>>>>> + > >>>>>> + val = read_sysreg_s(HISI_HIP08_CORE_COMMIT_REG); > >>>>>> + val &= ~HISI_HIP08_CORE_COMMIT_CLEAR; > >>>>>> + val |= enable << HISI_HIP08_CORE_COMMIT_SHIFT; > >>> > >>> I would use the explicitly masked values when you update > >>> a register. > >>> > >> ok, how about changing these code to this: > >> val &= ~GENMASK(12, 13); > > > > I would do : > > > > // Rename the HISI_HIP08_CORE_COMMIT_CLEAR to HISI_HIP08_CORE_COMMIT_MASK > > // above. > > #define HISI_HIP08_CORE_COMMIT_MASK 0x3000 > > > > #define HISI_HIP08_CORE_COMMIT_FULL 0b00 > > #define HISI_HIP08_CORE_COMMIT_LVL_1 0b01 > > > > > > u8 commit = enable ? HISI_HIP08_CORE_COMMIT_LVL_1 : HISI_HIP08_CORE_COMMIT_FULL; > > > > ... > > > > val |= commit << HISI_HIP08_CORE_COMMIT_SHIFT; > > > > .. > > > > > > Suzuki > > > > . > ok, I'll send a new version. :) > Please do so by tomorrow morning (North America time) if you want to see this going in the v5.11 merge window. Otherwise it will be another 3 months. > Thanks > Qi > > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel