From patchwork Wed Nov 23 15:35:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 83701 Delivered-To: patch@linaro.org Received: by 10.140.97.165 with SMTP id m34csp2700199qge; Wed, 23 Nov 2016 07:37:54 -0800 (PST) X-Received: by 10.99.202.72 with SMTP id o8mr6136837pgi.41.1479915474237; Wed, 23 Nov 2016 07:37:54 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id n6si5784489pla.24.2016.11.23.07.37.53; Wed, 23 Nov 2016 07:37:54 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965545AbcKWPhC (ORCPT + 25 others); Wed, 23 Nov 2016 10:37:02 -0500 Received: from mail.kernel.org ([198.145.29.136]:60360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965365AbcKWPfe (ORCPT ); Wed, 23 Nov 2016 10:35:34 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9A97E203DF; Wed, 23 Nov 2016 15:35:32 +0000 (UTC) Received: from gandalf.local.home (cpe-67-246-153-56.stny.res.rr.com [67.246.153.56]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 35A1F203F3; Wed, 23 Nov 2016 15:35:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.87) (envelope-from ) id 1c9Za5-0001G7-7i; Wed, 23 Nov 2016 10:35:29 -0500 Message-Id: <20161123153529.162702191@goodmis.org> User-Agent: quilt/0.63-1 Date: Wed, 23 Nov 2016 10:35:24 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Chunyan Zhang , Alexander Shishkin Subject: [for-next][PATCH 12/17] stm class: ftrace: Add ftrace-export-over-stm driver References: <20161123153512.923515549@goodmis.org> MIME-Version: 1.0 Content-Disposition: inline; filename=0012-stm-class-ftrace-Add-ftrace-export-over-stm-driver.patch X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chunyan Zhang This patch adds a driver that models itself as an stm_source called stm_ftrace. Once the stm device and stm_ftrace have been linked via sysfs, the driver registers itself as a trace_export and everything passed to the interface from Ftrace subsystem will end up in the STM trace engine. Link: http://lkml.kernel.org/r/1479715043-6534-3-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang Acked-by: Alexander Shishkin Signed-off-by: Steven Rostedt --- drivers/hwtracing/stm/Kconfig | 11 ++++++ drivers/hwtracing/stm/Makefile | 2 + drivers/hwtracing/stm/ftrace.c | 87 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 100 insertions(+) create mode 100644 drivers/hwtracing/stm/ftrace.c -- 2.10.2 diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig index 847a39b35307..723e2d90083d 100644 --- a/drivers/hwtracing/stm/Kconfig +++ b/drivers/hwtracing/stm/Kconfig @@ -39,4 +39,15 @@ config STM_SOURCE_HEARTBEAT If you want to send heartbeat messages over STM devices, say Y. +config STM_SOURCE_FTRACE + tristate "Copy the output from kernel Ftrace to STM engine" + depends on FUNCTION_TRACER + help + This option can be used to copy the output from kernel Ftrace + to STM engine. Enabling this option will introduce a slight + timing effect. + + If you want to send kernel Ftrace messages over STM devices, + say Y. + endif diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile index a9ce3d487e57..3abd84ce13d4 100644 --- a/drivers/hwtracing/stm/Makefile +++ b/drivers/hwtracing/stm/Makefile @@ -6,6 +6,8 @@ obj-$(CONFIG_STM_DUMMY) += dummy_stm.o obj-$(CONFIG_STM_SOURCE_CONSOLE) += stm_console.o obj-$(CONFIG_STM_SOURCE_HEARTBEAT) += stm_heartbeat.o +obj-$(CONFIG_STM_SOURCE_FTRACE) += stm_ftrace.o stm_console-y := console.o stm_heartbeat-y := heartbeat.o +stm_ftrace-y := ftrace.o diff --git a/drivers/hwtracing/stm/ftrace.c b/drivers/hwtracing/stm/ftrace.c new file mode 100644 index 000000000000..bd126a7c6da2 --- /dev/null +++ b/drivers/hwtracing/stm/ftrace.c @@ -0,0 +1,87 @@ +/* + * Simple kernel driver to link kernel Ftrace and an STM device + * Copyright (c) 2016, Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * STM Ftrace will be registered as a trace_export. + */ + +#include +#include +#include + +#define STM_FTRACE_NR_CHANNELS 1 +#define STM_FTRACE_CHAN 0 + +static int stm_ftrace_link(struct stm_source_data *data); +static void stm_ftrace_unlink(struct stm_source_data *data); + +static struct stm_ftrace { + struct stm_source_data data; + struct trace_export ftrace; +} stm_ftrace = { + .data = { + .name = "ftrace", + .nr_chans = STM_FTRACE_NR_CHANNELS, + .link = stm_ftrace_link, + .unlink = stm_ftrace_unlink, + }, +}; + +/** + * stm_ftrace_write() - write data to STM via 'stm_ftrace' source + * @buf: buffer containing the data packet + * @len: length of the data packet + */ +static void notrace +stm_ftrace_write(const void *buf, unsigned int len) +{ + stm_source_write(&stm_ftrace.data, STM_FTRACE_CHAN, buf, len); +} + +static int stm_ftrace_link(struct stm_source_data *data) +{ + struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data); + + sf->ftrace.write = stm_ftrace_write; + + return register_ftrace_export(&sf->ftrace); +} + +static void stm_ftrace_unlink(struct stm_source_data *data) +{ + struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data); + + unregister_ftrace_export(&sf->ftrace); +} + +static int __init stm_ftrace_init(void) +{ + int ret; + + ret = stm_source_register_device(NULL, &stm_ftrace.data); + if (ret) + pr_err("Failed to register stm_source - ftrace.\n"); + + return ret; +} + +static void __exit stm_ftrace_exit(void) +{ + stm_source_unregister_device(&stm_ftrace.data); +} + +module_init(stm_ftrace_init); +module_exit(stm_ftrace_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("stm_ftrace driver"); +MODULE_AUTHOR("Chunyan Zhang ");