| Message ID | 1476778140-10319-3-git-send-email-zhang.chunyan@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
On Tue, 18 Oct 2016 16:08:59 +0800 Chunyan Zhang <zhang.chunyan@linaro.org> wrote: > 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. > > Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> > --- > drivers/hwtracing/stm/Kconfig | 11 ++++++ > drivers/hwtracing/stm/Makefile | 2 + > drivers/hwtracing/stm/ftrace.c | 88 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 101 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 I think it should depend 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 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..1a114c8f > --- /dev/null > +++ b/drivers/hwtracing/stm/ftrace.c > @@ -0,0 +1,88 @@ > +/* > + * 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 <linux/module.h> > +#include <linux/stm.h> > +#include <linux/trace.h> > + > +#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); > + > + sf->ftrace.write = stm_ftrace_write; > + sf->ftrace.next = NULL; Why setting this to NULL? register_ftrace_export() should not require nor depend on that. -- Steve > + > + 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 <zhang.chunyan@linaro.org>");
On 19 October 2016 at 00:29, Steven Rostedt <rostedt@goodmis.org> wrote: > On Tue, 18 Oct 2016 16:08:59 +0800 > Chunyan Zhang <zhang.chunyan@linaro.org> wrote: > >> 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. >> >> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> >> --- >> drivers/hwtracing/stm/Kconfig | 11 ++++++ >> drivers/hwtracing/stm/Makefile | 2 + >> drivers/hwtracing/stm/ftrace.c | 88 ++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 101 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 > > I think it should depend on FUNCTION_TRACER I think we should support other type of tracer in the future, but you're right it only should depend on FUNCTION_TRACER for now, I will revise this. > >> + 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..1a114c8f >> --- /dev/null >> +++ b/drivers/hwtracing/stm/ftrace.c >> @@ -0,0 +1,88 @@ >> +/* >> + * 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 <linux/module.h> >> +#include <linux/stm.h> >> +#include <linux/trace.h> >> + >> +#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); >> + >> + sf->ftrace.write = stm_ftrace_write; >> + sf->ftrace.next = NULL; > > Why setting this to NULL? register_ftrace_export() should not require > nor depend on that. Right, it's not required indeed, will remove it. Thanks, Chunyan > > -- Steve > >> + >> + 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 <zhang.chunyan@linaro.org>"); >
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..1a114c8f --- /dev/null +++ b/drivers/hwtracing/stm/ftrace.c @@ -0,0 +1,88 @@ +/* + * 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 <linux/module.h> +#include <linux/stm.h> +#include <linux/trace.h> + +#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); + + sf->ftrace.write = stm_ftrace_write; + sf->ftrace.next = NULL; + + 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 <zhang.chunyan@linaro.org>");
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. Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> --- drivers/hwtracing/stm/Kconfig | 11 ++++++ drivers/hwtracing/stm/Makefile | 2 + drivers/hwtracing/stm/ftrace.c | 88 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 101 insertions(+) create mode 100644 drivers/hwtracing/stm/ftrace.c -- 2.7.4