diff mbox series

[v3,4/6] coresight: syscfg: Example CoreSight configuration loadable module

Message ID 20211124200038.28662-5-mike.leach@linaro.org (mailing list archive)
State New, archived
Headers show
Series coresight: syscfg: dynamic load | expand

Commit Message

Mike Leach Nov. 24, 2021, 8 p.m. UTC
An example of creating a loadable module to add CoreSight configurations
into a system.

In the Kernel samples/coresight directory.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 MAINTAINERS                              |  1 +
 samples/Kconfig                          |  9 +++
 samples/Makefile                         |  1 +
 samples/coresight/Makefile               |  4 ++
 samples/coresight/coresight-cfg-sample.c | 73 ++++++++++++++++++++++++
 5 files changed, 88 insertions(+)
 create mode 100644 samples/coresight/Makefile
 create mode 100644 samples/coresight/coresight-cfg-sample.c

Comments

Mathieu Poirier Nov. 26, 2021, 6:23 p.m. UTC | #1
On Wed, Nov 24, 2021 at 08:00:36PM +0000, Mike Leach wrote:
> An example of creating a loadable module to add CoreSight configurations
> into a system.
> 
> In the Kernel samples/coresight directory.
> 
> Signed-off-by: Mike Leach <mike.leach@linaro.org>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
>  MAINTAINERS                              |  1 +
>  samples/Kconfig                          |  9 +++
>  samples/Makefile                         |  1 +
>  samples/coresight/Makefile               |  4 ++
>  samples/coresight/coresight-cfg-sample.c | 73 ++++++++++++++++++++++++
>  5 files changed, 88 insertions(+)
>  create mode 100644 samples/coresight/Makefile
>  create mode 100644 samples/coresight/coresight-cfg-sample.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7a2345ce8521..85242fdd3b8c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1890,6 +1890,7 @@ F:	Documentation/trace/coresight/*
>  F:	drivers/hwtracing/coresight/*
>  F:	include/dt-bindings/arm/coresight-cti-dt.h
>  F:	include/linux/coresight*
> +F:	samples/coresight/*
>  F:	tools/perf/arch/arm/util/auxtrace.c
>  F:	tools/perf/arch/arm/util/cs-etm.c
>  F:	tools/perf/arch/arm/util/cs-etm.h
> diff --git a/samples/Kconfig b/samples/Kconfig
> index bec3528aa2de..fe8b56d576ce 100644
> --- a/samples/Kconfig
> +++ b/samples/Kconfig
> @@ -232,6 +232,15 @@ config SAMPLE_WATCH_QUEUE
>  	  Build example userspace program to use the new mount_notify(),
>  	  sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
>  
> +config SAMPLE_CORESIGHT_SYSCFG
> +	tristate "Build example loadable module for CoreSight config"
> +	depends on CORESIGHT && m
> +	help
> +	  Build an example loadable module that adds new CoreSight features
> +	  and configuration using the CoreSight system configuration API.
> +	  This demonstrates how a user may create their own CoreSight
> +	  configurations and easily load them into the system at runtime.
> +
>  endif # SAMPLES
>  
>  config HAVE_SAMPLE_FTRACE_DIRECT
> diff --git a/samples/Makefile b/samples/Makefile
> index b7b98307c2b4..c148ada64beb 100644
> --- a/samples/Makefile
> +++ b/samples/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_SAMPLE_INTEL_MEI)		+= mei/
>  subdir-$(CONFIG_SAMPLE_WATCHDOG)	+= watchdog
>  subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)	+= watch_queue
>  obj-$(CONFIG_DEBUG_KMEMLEAK_TEST)	+= kmemleak/
> +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG)	+= coresight/
> diff --git a/samples/coresight/Makefile b/samples/coresight/Makefile
> new file mode 100644
> index 000000000000..b3fce4af2347
> --- /dev/null
> +++ b/samples/coresight/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
> +ccflags-y += -I$(srctree)/drivers/hwtracing/coresight
> diff --git a/samples/coresight/coresight-cfg-sample.c b/samples/coresight/coresight-cfg-sample.c
> new file mode 100644
> index 000000000000..25485c80b5e3
> --- /dev/null
> +++ b/samples/coresight/coresight-cfg-sample.c
> @@ -0,0 +1,73 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright(C) 2020 Linaro Limited. All rights reserved.
> + * Author: Mike Leach <mike.leach@linaro.org>
> + */
> +
> +#include "coresight-config.h"
> +#include "coresight-syscfg.h"
> +
> +/* create an alternate autofdo configuration */
> +
> +/* we will provide 4 sets of preset parameter values */
> +#define AFDO2_NR_PRESETS	4
> +/* the total number of parameters in used features - strobing has 2 */
> +#define AFDO2_NR_PARAM_SUM	2
> +
> +static const char *afdo2_ref_names[] = {
> +	"strobing",

Checkpatch is complaining the above should be "static const char * const ..."  I
can't remember if we talked about this before - did we?

Do you want me to make the modification?
Mike Leach Nov. 29, 2021, 12:24 p.m. UTC | #2
Hi Mathieu,

On Fri, 26 Nov 2021 at 18:23, Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
>
> On Wed, Nov 24, 2021 at 08:00:36PM +0000, Mike Leach wrote:
> > An example of creating a loadable module to add CoreSight configurations
> > into a system.
> >
> > In the Kernel samples/coresight directory.
> >
> > Signed-off-by: Mike Leach <mike.leach@linaro.org>
> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> >  MAINTAINERS                              |  1 +
> >  samples/Kconfig                          |  9 +++
> >  samples/Makefile                         |  1 +
> >  samples/coresight/Makefile               |  4 ++
> >  samples/coresight/coresight-cfg-sample.c | 73 ++++++++++++++++++++++++
> >  5 files changed, 88 insertions(+)
> >  create mode 100644 samples/coresight/Makefile
> >  create mode 100644 samples/coresight/coresight-cfg-sample.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 7a2345ce8521..85242fdd3b8c 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -1890,6 +1890,7 @@ F:      Documentation/trace/coresight/*
> >  F:   drivers/hwtracing/coresight/*
> >  F:   include/dt-bindings/arm/coresight-cti-dt.h
> >  F:   include/linux/coresight*
> > +F:   samples/coresight/*
> >  F:   tools/perf/arch/arm/util/auxtrace.c
> >  F:   tools/perf/arch/arm/util/cs-etm.c
> >  F:   tools/perf/arch/arm/util/cs-etm.h
> > diff --git a/samples/Kconfig b/samples/Kconfig
> > index bec3528aa2de..fe8b56d576ce 100644
> > --- a/samples/Kconfig
> > +++ b/samples/Kconfig
> > @@ -232,6 +232,15 @@ config SAMPLE_WATCH_QUEUE
> >         Build example userspace program to use the new mount_notify(),
> >         sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
> >
> > +config SAMPLE_CORESIGHT_SYSCFG
> > +     tristate "Build example loadable module for CoreSight config"
> > +     depends on CORESIGHT && m
> > +     help
> > +       Build an example loadable module that adds new CoreSight features
> > +       and configuration using the CoreSight system configuration API.
> > +       This demonstrates how a user may create their own CoreSight
> > +       configurations and easily load them into the system at runtime.
> > +
> >  endif # SAMPLES
> >
> >  config HAVE_SAMPLE_FTRACE_DIRECT
> > diff --git a/samples/Makefile b/samples/Makefile
> > index b7b98307c2b4..c148ada64beb 100644
> > --- a/samples/Makefile
> > +++ b/samples/Makefile
> > @@ -32,3 +32,4 @@ obj-$(CONFIG_SAMPLE_INTEL_MEI)              += mei/
> >  subdir-$(CONFIG_SAMPLE_WATCHDOG)     += watchdog
> >  subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)  += watch_queue
> >  obj-$(CONFIG_DEBUG_KMEMLEAK_TEST)    += kmemleak/
> > +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG)        += coresight/
> > diff --git a/samples/coresight/Makefile b/samples/coresight/Makefile
> > new file mode 100644
> > index 000000000000..b3fce4af2347
> > --- /dev/null
> > +++ b/samples/coresight/Makefile
> > @@ -0,0 +1,4 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +
> > +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
> > +ccflags-y += -I$(srctree)/drivers/hwtracing/coresight
> > diff --git a/samples/coresight/coresight-cfg-sample.c b/samples/coresight/coresight-cfg-sample.c
> > new file mode 100644
> > index 000000000000..25485c80b5e3
> > --- /dev/null
> > +++ b/samples/coresight/coresight-cfg-sample.c
> > @@ -0,0 +1,73 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright(C) 2020 Linaro Limited. All rights reserved.
> > + * Author: Mike Leach <mike.leach@linaro.org>
> > + */
> > +
> > +#include "coresight-config.h"
> > +#include "coresight-syscfg.h"
> > +
> > +/* create an alternate autofdo configuration */
> > +
> > +/* we will provide 4 sets of preset parameter values */
> > +#define AFDO2_NR_PRESETS     4
> > +/* the total number of parameters in used features - strobing has 2 */
> > +#define AFDO2_NR_PARAM_SUM   2
> > +
> > +static const char *afdo2_ref_names[] = {
> > +     "strobing",
>
> Checkpatch is complaining the above should be "static const char * const ..."  I
> can't remember if we talked about this before - did we?
>

The first Complex config set had the same warning for the built in
autofdo config - which went upstream without issue.
The code is safe - the strings are only ever read, the array is not
altered  - so perhaps that is why it was permitted - or maybe it was
missed.

> Do you want me to make the modification?
>

When I first so the issue in the original patch series - I made the
suggested change and this had ripple effects of compile time warnings
- throwing away const.
If this is then corrected - the dynamic creation of configuration
descriptors from configfs input files (in the follow up patch set)
throws up errors
The only way round this I could see would be to have two versions of
the configuration descriptor - one that could be statically const
assigned in the code, and one that could be dynamically build from
file information.

Overall I am not convinced that there is a good fix for this
checkpatch warning  - and am not convinced that it is valid for this
usecase.

Regards

Mike
Mathieu Poirier Nov. 29, 2021, 4:44 p.m. UTC | #3
On Mon, 29 Nov 2021 at 05:24, Mike Leach <mike.leach@linaro.org> wrote:
>
> Hi Mathieu,
>
> On Fri, 26 Nov 2021 at 18:23, Mathieu Poirier
> <mathieu.poirier@linaro.org> wrote:
> >
> > On Wed, Nov 24, 2021 at 08:00:36PM +0000, Mike Leach wrote:
> > > An example of creating a loadable module to add CoreSight configurations
> > > into a system.
> > >
> > > In the Kernel samples/coresight directory.
> > >
> > > Signed-off-by: Mike Leach <mike.leach@linaro.org>
> > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > > ---
> > >  MAINTAINERS                              |  1 +
> > >  samples/Kconfig                          |  9 +++
> > >  samples/Makefile                         |  1 +
> > >  samples/coresight/Makefile               |  4 ++
> > >  samples/coresight/coresight-cfg-sample.c | 73 ++++++++++++++++++++++++
> > >  5 files changed, 88 insertions(+)
> > >  create mode 100644 samples/coresight/Makefile
> > >  create mode 100644 samples/coresight/coresight-cfg-sample.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 7a2345ce8521..85242fdd3b8c 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -1890,6 +1890,7 @@ F:      Documentation/trace/coresight/*
> > >  F:   drivers/hwtracing/coresight/*
> > >  F:   include/dt-bindings/arm/coresight-cti-dt.h
> > >  F:   include/linux/coresight*
> > > +F:   samples/coresight/*
> > >  F:   tools/perf/arch/arm/util/auxtrace.c
> > >  F:   tools/perf/arch/arm/util/cs-etm.c
> > >  F:   tools/perf/arch/arm/util/cs-etm.h
> > > diff --git a/samples/Kconfig b/samples/Kconfig
> > > index bec3528aa2de..fe8b56d576ce 100644
> > > --- a/samples/Kconfig
> > > +++ b/samples/Kconfig
> > > @@ -232,6 +232,15 @@ config SAMPLE_WATCH_QUEUE
> > >         Build example userspace program to use the new mount_notify(),
> > >         sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
> > >
> > > +config SAMPLE_CORESIGHT_SYSCFG
> > > +     tristate "Build example loadable module for CoreSight config"
> > > +     depends on CORESIGHT && m
> > > +     help
> > > +       Build an example loadable module that adds new CoreSight features
> > > +       and configuration using the CoreSight system configuration API.
> > > +       This demonstrates how a user may create their own CoreSight
> > > +       configurations and easily load them into the system at runtime.
> > > +
> > >  endif # SAMPLES
> > >
> > >  config HAVE_SAMPLE_FTRACE_DIRECT
> > > diff --git a/samples/Makefile b/samples/Makefile
> > > index b7b98307c2b4..c148ada64beb 100644
> > > --- a/samples/Makefile
> > > +++ b/samples/Makefile
> > > @@ -32,3 +32,4 @@ obj-$(CONFIG_SAMPLE_INTEL_MEI)              += mei/
> > >  subdir-$(CONFIG_SAMPLE_WATCHDOG)     += watchdog
> > >  subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)  += watch_queue
> > >  obj-$(CONFIG_DEBUG_KMEMLEAK_TEST)    += kmemleak/
> > > +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG)        += coresight/
> > > diff --git a/samples/coresight/Makefile b/samples/coresight/Makefile
> > > new file mode 100644
> > > index 000000000000..b3fce4af2347
> > > --- /dev/null
> > > +++ b/samples/coresight/Makefile
> > > @@ -0,0 +1,4 @@
> > > +# SPDX-License-Identifier: GPL-2.0-only
> > > +
> > > +obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
> > > +ccflags-y += -I$(srctree)/drivers/hwtracing/coresight
> > > diff --git a/samples/coresight/coresight-cfg-sample.c b/samples/coresight/coresight-cfg-sample.c
> > > new file mode 100644
> > > index 000000000000..25485c80b5e3
> > > --- /dev/null
> > > +++ b/samples/coresight/coresight-cfg-sample.c
> > > @@ -0,0 +1,73 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Copyright(C) 2020 Linaro Limited. All rights reserved.
> > > + * Author: Mike Leach <mike.leach@linaro.org>
> > > + */
> > > +
> > > +#include "coresight-config.h"
> > > +#include "coresight-syscfg.h"
> > > +
> > > +/* create an alternate autofdo configuration */
> > > +
> > > +/* we will provide 4 sets of preset parameter values */
> > > +#define AFDO2_NR_PRESETS     4
> > > +/* the total number of parameters in used features - strobing has 2 */
> > > +#define AFDO2_NR_PARAM_SUM   2
> > > +
> > > +static const char *afdo2_ref_names[] = {
> > > +     "strobing",
> >
> > Checkpatch is complaining the above should be "static const char * const ..."  I
> > can't remember if we talked about this before - did we?
> >
>
> The first Complex config set had the same warning for the built in
> autofdo config - which went upstream without issue.
> The code is safe - the strings are only ever read, the array is not
> altered  - so perhaps that is why it was permitted - or maybe it was
> missed.
>
> > Do you want me to make the modification?
> >
>
> When I first so the issue in the original patch series - I made the
> suggested change and this had ripple effects of compile time warnings
> - throwing away const.
> If this is then corrected - the dynamic creation of configuration
> descriptors from configfs input files (in the follow up patch set)
> throws up errors
> The only way round this I could see would be to have two versions of
> the configuration descriptor - one that could be statically const
> assigned in the code, and one that could be dynamically build from
> file information.
>
> Overall I am not convinced that there is a good fix for this
> checkpatch warning  - and am not convinced that it is valid for this
> usecase.

... and I am definitely not convinced it is worth spending the time to fix this.

I have applied this patchset.

Thanks,
Mathieu

>
> Regards
>
> Mike
>
> --
> Mike Leach
> Principal Engineer, ARM Ltd.
> Manchester Design Centre. UK
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 7a2345ce8521..85242fdd3b8c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1890,6 +1890,7 @@  F:	Documentation/trace/coresight/*
 F:	drivers/hwtracing/coresight/*
 F:	include/dt-bindings/arm/coresight-cti-dt.h
 F:	include/linux/coresight*
+F:	samples/coresight/*
 F:	tools/perf/arch/arm/util/auxtrace.c
 F:	tools/perf/arch/arm/util/cs-etm.c
 F:	tools/perf/arch/arm/util/cs-etm.h
diff --git a/samples/Kconfig b/samples/Kconfig
index bec3528aa2de..fe8b56d576ce 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -232,6 +232,15 @@  config SAMPLE_WATCH_QUEUE
 	  Build example userspace program to use the new mount_notify(),
 	  sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
 
+config SAMPLE_CORESIGHT_SYSCFG
+	tristate "Build example loadable module for CoreSight config"
+	depends on CORESIGHT && m
+	help
+	  Build an example loadable module that adds new CoreSight features
+	  and configuration using the CoreSight system configuration API.
+	  This demonstrates how a user may create their own CoreSight
+	  configurations and easily load them into the system at runtime.
+
 endif # SAMPLES
 
 config HAVE_SAMPLE_FTRACE_DIRECT
diff --git a/samples/Makefile b/samples/Makefile
index b7b98307c2b4..c148ada64beb 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -32,3 +32,4 @@  obj-$(CONFIG_SAMPLE_INTEL_MEI)		+= mei/
 subdir-$(CONFIG_SAMPLE_WATCHDOG)	+= watchdog
 subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)	+= watch_queue
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST)	+= kmemleak/
+obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG)	+= coresight/
diff --git a/samples/coresight/Makefile b/samples/coresight/Makefile
new file mode 100644
index 000000000000..b3fce4af2347
--- /dev/null
+++ b/samples/coresight/Makefile
@@ -0,0 +1,4 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
+ccflags-y += -I$(srctree)/drivers/hwtracing/coresight
diff --git a/samples/coresight/coresight-cfg-sample.c b/samples/coresight/coresight-cfg-sample.c
new file mode 100644
index 000000000000..25485c80b5e3
--- /dev/null
+++ b/samples/coresight/coresight-cfg-sample.c
@@ -0,0 +1,73 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(C) 2020 Linaro Limited. All rights reserved.
+ * Author: Mike Leach <mike.leach@linaro.org>
+ */
+
+#include "coresight-config.h"
+#include "coresight-syscfg.h"
+
+/* create an alternate autofdo configuration */
+
+/* we will provide 4 sets of preset parameter values */
+#define AFDO2_NR_PRESETS	4
+/* the total number of parameters in used features - strobing has 2 */
+#define AFDO2_NR_PARAM_SUM	2
+
+static const char *afdo2_ref_names[] = {
+	"strobing",
+};
+
+/*
+ * set of presets leaves strobing window constant while varying period to allow
+ * experimentation with mark / space ratios for various workloads
+ */
+static u64 afdo2_presets[AFDO2_NR_PRESETS][AFDO2_NR_PARAM_SUM] = {
+	{ 1000, 100 },
+	{ 1000, 1000 },
+	{ 1000, 5000 },
+	{ 1000, 10000 },
+};
+
+struct cscfg_config_desc afdo2 = {
+	.name = "autofdo2",
+	.description = "Setup ETMs with strobing for autofdo\n"
+	"Supplied presets allow experimentation with mark-space ratio for various loads\n",
+	.nr_feat_refs = ARRAY_SIZE(afdo2_ref_names),
+	.feat_ref_names = afdo2_ref_names,
+	.nr_presets = AFDO2_NR_PRESETS,
+	.nr_total_params = AFDO2_NR_PARAM_SUM,
+	.presets = &afdo2_presets[0][0],
+};
+
+static struct cscfg_feature_desc *sample_feats[] = {
+	NULL
+};
+
+static struct cscfg_config_desc *sample_cfgs[] = {
+	&afdo2,
+	NULL
+};
+
+static struct cscfg_load_owner_info mod_owner = {
+	.type = CSCFG_OWNER_MODULE,
+	.owner_handle = THIS_MODULE,
+};
+
+/* module init and exit - just load and unload configs */
+static int __init cscfg_sample_init(void)
+{
+	return cscfg_load_config_sets(sample_cfgs, sample_feats, &mod_owner);
+}
+
+static void __exit cscfg_sample_exit(void)
+{
+	cscfg_unload_config_sets(&mod_owner);
+}
+
+module_init(cscfg_sample_init);
+module_exit(cscfg_sample_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mike Leach <mike.leach@linaro.org>");
+MODULE_DESCRIPTION("CoreSight Syscfg Example");