Commit ede5bab8 authored by Mike Leach's avatar Mike Leach Committed by Mathieu Poirier
Browse files

coresight: syscfg: Example CoreSight configuration loadable module 



An example of creating a loadable module to add CoreSight configurations
into a system.

In the Kernel samples/coresight directory.

Signed-off-by: default avatarMike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20211124200038.28662-5-mike.leach@linaro.org


Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
parent eb2ec496

MAINTAINERS

+1 −0
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@@ -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

samples/Kconfig

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@@ -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

samples/Makefile

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@@ -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/

samples/coresight/Makefile

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# SPDX-License-Identifier: GPL-2.0-only



obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o

ccflags-y += -I$(srctree)/drivers/hwtracing/coresight

samples/coresight/coresight-cfg-sample.c

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// 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");