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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D1F5DC48BDF for ; Tue, 15 Jun 2021 09:35:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8F136144E for ; Tue, 15 Jun 2021 09:35:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231401AbhFOJhc (ORCPT ); Tue, 15 Jun 2021 05:37:32 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:7273 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231325AbhFOJhR (ORCPT ); Tue, 15 Jun 2021 05:37:17 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4G432C1JHfz1BMD5; Tue, 15 Jun 2021 17:30:11 +0800 (CST) Received: from dggema757-chm.china.huawei.com (10.1.198.199) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Tue, 15 Jun 2021 17:35:10 +0800 Received: from localhost.localdomain (10.69.192.56) by dggema757-chm.china.huawei.com (10.1.198.199) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 15 Jun 2021 17:35:10 +0800 From: Qi Liu To: , , , , CC: , , , Subject: [RFC PATCH 1/4] Documentation: tracing: Documentation for ultrasoc framework and drivers Date: Tue, 15 Jun 2021 17:34:41 +0800 Message-ID: <1623749684-65432-2-git-send-email-liuqi115@huawei.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1623749684-65432-1-git-send-email-liuqi115@huawei.com> References: <1623749684-65432-1-git-send-email-liuqi115@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggema757-chm.china.huawei.com (10.1.198.199) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ultrasoc trace module is a system level solution for both core tracing and SoC tracing. This patch brings in a documentation for ultrasoc framework and drivers. It simply introduces function of ultrasoc, a typical Ultrasoc system, and a driver framework for ultrasoc. Signed-off-by: Jonathan Zhou Signed-off-by: Qi Liu --- Documentation/trace/ultrasoc-trace.rst | 209 +++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 Documentation/trace/ultrasoc-trace.rst diff --git a/Documentation/trace/ultrasoc-trace.rst b/Documentation/trace/ultrasoc-trace.rst new file mode 100644 index 0000000..36d2df2 --- /dev/null +++ b/Documentation/trace/ultrasoc-trace.rst @@ -0,0 +1,209 @@ +======================================================= +Siemens Embedded Analytics - HW Assisted Tracing on SoC +======================================================= + :Author: Jonathan Zhou + Qi Liu + :Date: January 16th, 2021 + +Introduction +------------ + +The Siemens Embedded Analytics Framework is system level solution for tracing +of multiple type SoC, this document is concerned with trace module. This module +has two main components: AXI Bus Communicator and System Memory Buffer. + +The AXI Communicator has upstream and downstream channels, the upstream channel +is used to transmit user configuration, and downstream channel to carry response +and trace data to the users. + +The System Memory Buffer provides a way to buffer and store messages in system +memory. It provides a capability to store messages received on its input message +interface to an area of system memory. + +A typical Siemens trace system would look like the following diagram: + @@@@@@@@@@@@@ + @ CPU @ + @@@@@@@@@@@@@ + ############# + # Coresight # + # ETM # + ####### + ### + # + | + * + ******************************* + *** AMBA Advanced Trace Bus (ATB) *** + ***************^*************** + =============== | + === FUNNEL ==<--- | + ======= + | + * + @@@@@@@ + @ TRC @ + @@@@@ + @@@ + @ + | + * + ************************************** ******************* + ************************ Message BUS *************************** + ******************^************************^**************** + | | + @@@@@@@@@@@@@@@@@@ | @@@@@@@@@@@@ + @ Message Engine @ | @ JTAG COM @ + @@@@@@@@@@@@@@@@@@ | @@@@@@@@@@ + | * |---> @@@@@@@@ + | | @@@@@@ + @@@@@@@ | @@@@@@@@@@@ | + @ SMB @ | @ AXI COM @ JTAG + @@@@@ |--> @@@@@@@@@ + @@@--| @@@@@@@ + @ | @@@@@ + | | + | | + * * + *************************************************************** + **************************** AMBA AXI **************************** + ***************************************************************** + +Acronyms +--------------------------- + +Acronyms: + +AXI-COM: AXI Communicator +SMB: System Memory Buffer +TRC: Trace receiver + +Framework and implementation +------------------------------ + +Siemens Embedded Analytics Framework is implemented as a platform device. The +platform device provides a global point to configure the Embedded Analytics +subsystem, and also provides a ``struct ultrasoc_com`` to manage AXI-COM and +SMB. + +AXI-COM and SMB are implemented as platform devices, each SCCL has one AXI-COM +device and one SMB device. AXI-COM and SMB can use the following API to register +into Embedded Analytics framework: +.. c:function:: struct ultrasoc_com *ultrasoc_register_com(struct device *root_dev, struct ultrasoc_com_descp *com_descp) +.. c:function:: void ultrasoc_unregister_com(struct ultrasoc_com *com); + +As TRC receives data from coresight ETM device, SMB can use the following API +to register into coresight framework as a sink device: +.. c:function:: struct coresight_device *coresight_register(struct coresight_desc *desc); +.. c:function:: void coresight_unregister(struct coresight_device *csdev); + +Then users can get trace data by this path: ETM->funnel->SMB->System Memory. +More information about coresight framework can be found in +Documention/trace/coresight/coresight.rst. + +If everything goes well, the relationship of Embedded Analytics devices will be +described under the sysfs:: + + $# ls /sys/bus/platform/devices/ + :00 :00 :00 + $# ls /sys/bus/platform/devices/:00 + com_mux firmware_node power :00 + driver message subsystem :00 + driver_override modalias uevent + $# ls /sys/bus/coresight/devices/ + etm0 etm14 etm2 etm25 etm30 etm8 funnel4 + etm1 etm15 etm20 etm26 etm31 etm9 funnel5 + etm10 etm16 etm21 etm27 etm4 funnel0 funnel6 + etm11 etm17 etm22 etm28 etm5 funnel1 funnel7 + etm12 etm18 etm23 etm29 etm6 funnel2 sink_smb0 + etm13 etm19 etm24 etm3 etm7 funnel3 + $# ls -l /sys/bus/coresight/devices/funnel0/connections/ + in:0 -> ../../../../system/cpu/cpu0/ARMHC500:00/etm0 + in:1 -> ../../../../system/cpu/cpu1/ARMHC500:01/etm1 + in:2 -> ../../../../system/cpu/cpu2/ARMHC500:02/etm2 + in:3 -> ../../../../system/cpu/cpu3/ARMHC500:03/etm3 + nr_links + out:0 -> ../../../HISI0391:00/HISI03A1:00/sink_smb0 + $# ls -l /sys/bus/coresight/devices/sink_smb0/connections/ + in:101 -> ../../../../ARMHC9FE:05/funnel5 + in:114 -> ../../../../ARMHC9FE:07/funnel7 + in:121 -> ../../../../ARMHC9FE:03/funnel3 + in:39 -> ../../../../ARMHC9FE:00/funnel0 + in:51 -> ../../../../ARMHC9FE:04/funnel4 + in:61 -> ../../../../ARMHC9FE:06/funnel6 + in:68 -> ../../../../ARMHC9FE:02/funnel2 + in:89 -> ../../../../ARMHC9FE:01/funnel1 + nr_links + +How to use the Embedded Analytics trace module +----------------------------------------------- + +There are two ways to use the Embedded Analytics trace module: + +1. interacting directly with the devices using the sysFS interface. +2. using the perf cmd line tools. + +1) Using the sysFS interface: + +Before trace collection can start, a coresight sink needs to be identified. +There is no limit on the amount of sinks (nor sources) that can be enabled at +any given moment. As a generic operation, all device pertaining to the sink +class will have an "active" entry in sysfs:: + + $# ls /sys/bus/coresight/devices/ + etm0 etm14 etm2 etm25 etm30 etm8 funnel4 + etm1 etm15 etm20 etm26 etm31 etm9 funnel5 + etm10 etm16 etm21 etm27 etm4 funnel0 funnel6 + etm11 etm17 etm22 etm28 etm5 funnel1 funnel7 + etm12 etm18 etm23 etm29 etm6 funnel2 sink_smb0 + etm13 etm19 etm24 etm3 etm7 funnel3 + $# ls /sys/bus/coresight/devices/sink_smb0 + connections enable_sink firmware_node power subsystem uevent + $# echo 1 > /sys/bus/coresight/devices/sink_smb0/enable_sink + $# cat /sys/bus/coresight/devices/sink_smb0/enable_sink + 1 + +When start trace collection, etm devices corresponding to the enabled sink +should be selected:: + + $# echo 1 > /sys/bus/coresight/devices/etm0/enable_source + $# cat /sys/bus/coresight/devices/etm0/enable_source + 1 + $# cat /sys/bus/platform/devices/:00/com_status + com-type : DOWN-ONLY + service status : stopped + interrupt status : 0x00000003 + write point : 0x5437f400 <----- The write pointer is moving + +Trace collection is stopped the same way:: + + $# echo 0 > /sys/bus/coresight/devices/etm0/enable_source + $# echo 0 > /sys/bus/coresight/devices/sink_smb0/enable_sink + +The content of the SMB buffer can be harvested directly from /dev:: + + $# dd if=/dev/sink_smb0 of=~/cstrace.bin + 5233+0 records in + 5233+0 records out + 2679296 bytes (2.7 MB) copied, 0.0131708 s, 203 MB/s + + root:/sys/bus/coresight/devices# + +The file cstrace.bin can be decompressed using "ptm2human". + +2) Using perf framework: + +As SMB device has been registered with coresight framework, perf tool can be +used to control Embedded Analytics trace collection, and the method is similar +to using perf to do coresight trace collection. + +The only thing to note is, list of cpus should be correspond to the specified +sink device. + +Example usage of perf:: + + $# ./perf list pmu + cs_etm// [Kernel PMU event] + $# ./perf record -e cs_etm/@sink_smb0/ -C 0 --per-thread sleep 2s + [ perf record: Woken up 2 times to write data ] + [ perf record: Captured and wrote 0.288 MB perf.data ] + $# ./perf report -- 2.7.4