Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753556AbbFEFhK (ORCPT ); Fri, 5 Jun 2015 01:37:10 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:36261 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751463AbbFEFhE (ORCPT ); Fri, 5 Jun 2015 01:37:04 -0400 MIME-Version: 1.0 Date: Fri, 5 Jun 2015 13:37:03 +0800 Message-ID: Subject: [RFC PATCH 1/3] STM trace event: Adding generic buffer interface driver From: Chunyan Zhang To: Steven Rostedt , mingo@redhat.com Cc: Mathieu Poirier , Kaixu Xia , Serge Broslavsky , Mark Brown , alexander.shishkin@linux.intel.com, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3605 Lines: 107 From: Mathieu Poirier This patch adds a driver that models itself as an stm_source and who's sole purpose is to export an interface to the rest of the kernel. Once the stm and stm_source have been linked via sysfs, everything that is passed to the interface will endup in the STM trace engine. Signed-off-by: Mathieu Poirier Signed-off-by: Chunyan Zhang --- drivers/stm/Kconfig | 11 +++++++++++ drivers/stm/Makefile | 2 ++ drivers/stm/stm_trace_event.c | 46 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 59 insertions(+) create mode 100644 drivers/stm/stm_trace_event.c diff --git a/drivers/stm/Kconfig b/drivers/stm/Kconfig index 6f2db70..8ead418 100644 --- a/drivers/stm/Kconfig +++ b/drivers/stm/Kconfig @@ -25,3 +25,14 @@ config STM_SOURCE_CONSOLE If you want to send kernel console messages over STM devices, say Y. + +config STM_TRACE_EVENT + tristate "Redirect/copy the output from kernel trace event to STM engine" + depends on STM + help + This option can be used to redirect or copy the output from kernel trace + event to STM engine. Enabling this option will introduce a slight + timing effect. + + If you want to send kernel trace event messages over STM devices, + say Y. diff --git a/drivers/stm/Makefile b/drivers/stm/Makefile index 74baf59..55b152c 100644 --- a/drivers/stm/Makefile +++ b/drivers/stm/Makefile @@ -5,3 +5,5 @@ stm_core-y := core.o policy.o obj-$(CONFIG_STM_DUMMY) += dummy_stm.o obj-$(CONFIG_STM_SOURCE_CONSOLE) += console.o + +obj-$(CONFIG_STM_TRACE_EVENT) += stm_trace_event.o diff --git a/drivers/stm/stm_trace_event.c b/drivers/stm/stm_trace_event.c new file mode 100644 index 0000000..0d787ce --- /dev/null +++ b/drivers/stm/stm_trace_event.c @@ -0,0 +1,46 @@ +/* + * Simple kernel driver to link kernel trace event and an STM device + * Copyright (c) 2015, 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 +#include +#include + +static struct stm_source_data stm_trace_event_data = { + .name = "stm_trace_event", + .nr_chans = 1, +}; + +void stm_trace_event_write(const char *buf, unsigned len) +{ + stm_source_write(&stm_trace_event_data, 0, buf, len); +} + +static int stm_trace_event_init(void) +{ + return stm_source_register_device(NULL, &stm_trace_event_data); +} + +static void stm_trace_event_exit(void) +{ + stm_source_unregister_device(&stm_trace_event_data); +} + +module_init(stm_trace_event_init); +module_exit(stm_trace_event_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("stm_trace_event driver"); +MODULE_AUTHOR("Mathieu Poirier "); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/