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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F9B2C433F5 for ; Mon, 6 Dec 2021 08:29:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239317AbhLFIcz (ORCPT ); Mon, 6 Dec 2021 03:32:55 -0500 Received: from alexa-out.qualcomm.com ([129.46.98.28]:3827 "EHLO alexa-out.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239226AbhLFIcx (ORCPT ); Mon, 6 Dec 2021 03:32:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1638779366; x=1670315366; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=sDxxks2ISanKCZutPVRC7KEeBXIXNr8hG9VHZXbESTI=; b=BWR2MDrDOV+cTlrJIABb2eo4Hy+d00eZ0+7O6v0J49Nbo1GP5XF8WyYK O/OPAY1tFXp/0ZN+L/EUc7gsVbfxwxIJaolCsPkePOmQqmJYeMwgk3qkl WEz9BXNRlA2tIwNAxvHs4DwzYIyzs62VPS8qj2nhrTCld6sZsI9jd42NK k=; Received: from ironmsg-lv-alpha.qualcomm.com ([10.47.202.13]) by alexa-out.qualcomm.com with ESMTP; 06 Dec 2021 00:29:25 -0800 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg-lv-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2021 00:29:09 -0800 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Mon, 6 Dec 2021 00:29:09 -0800 Received: from blr-ubuntu-311.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Mon, 6 Dec 2021 00:29:05 -0800 From: Sai Prakash Ranjan To: Will Deacon , Catalin Marinas , Arnd Bergmann , Steven Rostedt , "Marc Zyngier" CC: gregkh , , , , , Sai Prakash Ranjan Subject: [PATCHv5 0/4] tracing/rwmmio/arm64: Add support to trace register reads/writes Date: Mon, 6 Dec 2021 13:58:02 +0530 Message-ID: X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Generic MMIO read/write i.e., __raw_{read,write}{b,l,w,q} accessors are typically used to read/write from/to memory mapped registers and can cause hangs or some undefined behaviour in following cases, * If the access to the register space is unclocked, for example: if there is an access to multimedia(MM) block registers without MM clocks. * If the register space is protected and not set to be accessible from non-secure world, for example: only EL3 (EL: Exception level) access is allowed and any EL2/EL1 access is forbidden. * If xPU(memory/register protection units) is controlling access to certain memory/register space for specific clients. and more... Such cases usually results in instant reboot/SErrors/NOC or interconnect hangs and tracing these register accesses can be very helpful to debug such issues during initial development stages and also in later stages. So use ftrace trace events to log such MMIO register accesses which provides rich feature set such as early enablement of trace events, filtering capability, dumping ftrace logs on console and many more. Sample output: rwmmio_read: gic_peek_irq+0xd0/0xd8 readl addr=0xffff800010040104 rwmmio_write: gic_poke_irq+0xe4/0xf0 writel addr=0xffff800010040184 rwmmio_read: gic_do_wait_for_rwp+0x54/0x90 readl addr=0xffff800010040000 rwmmio_write: gic_set_affinity+0x1bc/0x1e8 writeq addr=0xffff800010046130 This series is a follow-up for the series [1] and a recent series [2] making use of both. [1] https://lore.kernel.org/lkml/cover.1536430404.git.saiprakash.ranjan@codeaurora.org/ [2] https://lore.kernel.org/lkml/1604631386-178312-1-git-send-email-psodagud@codeaurora.org/ Note in previous version, Arnd suggested to benchmark and compare size with callback based implementation, please see [3] for more details on that with brief comparison below. **Inline version with CONFIG_FTRACE=y and CONFIG_TRACE_MMIO_ACCESS=y** $ size vmlinux text data bss dec hex filename 23884219 14284468 532568 38701255 24e88c7 vmlinux **Callback version with CONFIG_FTRACE=y and CONFIG_TRACE_MMIO_ACCESS=y** $ size vmlinux text data bss dec hex filename 24108179 14279596 532568 38920343 251e097 vmlinux $ ./scripts/bloat-o-meter inline-vmlinux callback-vmlinux add/remove: 8/3 grow/shrink: 4889/89 up/down: 242244/-11564 (230680) Total: Before=25812612, After=26043292, chg +0.89% [3] https://lore.kernel.org/lkml/466449a1-36da-aaa9-7e4f-477f36b52c9e@quicinc.com/ Changes in v5: * Move arm64 to use asm-generic provided high level MMIO accessors (Arnd). * Add inline logging for MMIO relaxed and non-relaxed accessors. * Move nVHE KVM comment to makefile (Marc). * Fix overflow warning due to switch to inline accessors instead of macro. * Modify trace event field to include caller and parent details for more detailed logs. Changes in v4: * Drop dynamic debug based filter support since that will be developed later with the help from Steven (Ftrace maintainer). * Drop value passed to writel as it is causing hangs when tracing is enabled. * Code cleanup for trace event as suggested by Steven for earlier version. * Fixed some build errors reported by 0-day bot. Changes in v3: * Create a generic mmio header for instrumented version (Earlier suggested in [1] by Will Deacon and recently [2] by Greg to have a generic version first). * Add dynamic debug support to filter out traces which can be very useful for targeted debugging specific to subsystems or drivers. * Few modifications to the rwmmio trace event fields to include the mmio width and print addresses in hex. * Rewrote commit msg to explain some more about usecases. Prasad Sodagudi (1): tracing: Add register read/write tracing support Sai Prakash Ranjan (3): arm64: io: Use asm-generic high level MMIO accessors irqchip/tegra: Fix overflow implicit truncation warnings asm-generic/io: Add logging support for MMIO accessors arch/arm64/include/asm/io.h | 33 ++------------- arch/arm64/kvm/hyp/nvhe/Makefile | 7 +++- drivers/irqchip/irq-tegra.c | 10 ++--- include/asm-generic/io.h | 49 +++++++++++++++++++++++ include/trace/events/rwmmio.h | 69 ++++++++++++++++++++++++++++++++ kernel/trace/Kconfig | 7 ++++ kernel/trace/Makefile | 1 + kernel/trace/trace_readwrite.c | 29 ++++++++++++++ 8 files changed, 170 insertions(+), 35 deletions(-) create mode 100644 include/trace/events/rwmmio.h create mode 100644 kernel/trace/trace_readwrite.c -- 2.33.1