From patchwork Mon Aug 15 11:50:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chunyan Zhang X-Patchwork-Id: 9280839 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id ACA4960467 for ; Mon, 15 Aug 2016 11:53:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9C1F628C4B for ; Mon, 15 Aug 2016 11:53:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 903F228C51; Mon, 15 Aug 2016 11:53:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7981E28C4B for ; Mon, 15 Aug 2016 11:52:58 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bZGQg-00085g-9C; Mon, 15 Aug 2016 11:51:42 +0000 Received: from mail-pa0-x230.google.com ([2607:f8b0:400e:c03::230]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bZGQO-0007qj-BX for linux-arm-kernel@lists.infradead.org; Mon, 15 Aug 2016 11:51:28 +0000 Received: by mail-pa0-x230.google.com with SMTP id ti13so15853720pac.0 for ; Mon, 15 Aug 2016 04:51:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=X/ETFxDGt07h20Qh8LMGcdq0ejV2vFPD+XscOq7cPmU=; b=Ku1NEh/3u9Q38GPeKT7GL5y1QrMoa/ndaFKqYDBJkIFJjcLkzV/P/esL/hIXEZg7ei pNao1+fnR+NuNqZB6vwvqF3PSl6fhR1njIAV9wA+kAWQzXG4AxXZuocC5bITFlHf8cCi ODQQQyHTghNwxcGyhY9m/XVcxS4FBAGiKHTuQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=X/ETFxDGt07h20Qh8LMGcdq0ejV2vFPD+XscOq7cPmU=; b=J1DvFVkDVZoiD57h5V7dFh8u9Z7SbZvh3FI3nR5dvbnABXQxGZPtt84dx/wSNBeYYp iTzAvsDvYIIVouqn2MZRsI4SORXpx/fdBsLPX33OgZMuqsCg9gWwCuHFZX476Y87ZIb7 oXYZIbFTO2vXMNh8HBI8khVsbcrBkeh9tq/rTIeKHCA4QP+n3s2rVuRNvuRRFtJz01un kZG6DRzUVHbqV1h55DCTaixnI3f25UhzDiNx2CyYKcODMN/DbIepVmIT/AXhjFxqaETA spRYNbSO1F4cOblf26ttFAGSnDC0Sc9kJKN8/Ff2m4YBhvhNtkkiq7tWlrdMsdqa0AGA KH8w== X-Gm-Message-State: AEkoouttP//WbFmBmtDigJjZARsxLL3eoLhnEGBc6Ovo73JpgvEYQqlipibgDs9RrO/8OXjD X-Received: by 10.66.43.234 with SMTP id z10mr52874352pal.137.1471261863157; Mon, 15 Aug 2016 04:51:03 -0700 (PDT) Received: from ubuntu16.spreadtrum.com ([175.111.195.49]) by smtp.gmail.com with ESMTPSA id x66sm31275769pfb.86.2016.08.15.04.50.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 15 Aug 2016 04:51:02 -0700 (PDT) From: Chunyan Zhang To: rostedt@goodmis.org, mathieu.poirier@linaro.org, alexander.shishkin@linux.intel.com, mingo@redhat.com Subject: [PATCH V4 2/3] stm class: ftrace: Add ftrace-export-over-stm driver Date: Mon, 15 Aug 2016 19:50:02 +0800 Message-Id: <1471261803-1186-3-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1471261803-1186-1-git-send-email-zhang.chunyan@linaro.org> References: <1471261803-1186-1-git-send-email-zhang.chunyan@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160815_045124_566959_1BEA3F40 X-CRM114-Status: GOOD ( 20.57 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: arnd@arndb.de, felipe.balbi@linux.intel.com, zhang.lyra@gmail.com, linux-kernel@vger.kernel.org, tor@ti.com, philippe.langlais@st.com, mike.leach@arm.com, nicolas.guion@st.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds a driver that models itself as an stm_source and registers itself as a trace_export. Once the stm and stm_source have been linked via sysfs, everything that is passed to the interface from Ftrace subsystem will endup in the STM trace engine. Signed-off-by: Chunyan Zhang --- 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 diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig index 847a39b..b34ea96 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 TRACING + 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 a9ce3d4..3abd84c 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 0000000..1101f46 --- /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. + */ + +#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 char *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); + + strcpy(sf->ftrace.name, "stm_ftrace"); + sf->ftrace.write = stm_ftrace_write; + sf->ftrace.next = NULL; + + return register_trace_export(&sf->ftrace); +} + +static void stm_ftrace_unlink(struct stm_source_data *data) +{ + struct stm_ftrace *sc = container_of(data, struct stm_ftrace, data); + + unregister_trace_export(&sc->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 ");