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authorMike Leach <mike.leach@linaro.org>2021-11-24 20:00:36 +0000
committerMathieu Poirier <mathieu.poirier@linaro.org>2021-11-26 11:34:07 -0700
commitede5bab874f535355ccee5514383941b9525c03b (patch)
tree9273638395eda53757447b2978cd70a938024a10 /samples
parenteb2ec49606c2a02d6382d56a0e19f34e515fde3f (diff)
downloadlwn-ede5bab874f535355ccee5514383941b9525c03b.tar.gz
lwn-ede5bab874f535355ccee5514383941b9525c03b.zip
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: Mike Leach <mike.leach@linaro.org> Link: https://lore.kernel.org/r/20211124200038.28662-5-mike.leach@linaro.org Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'samples')
-rw-r--r--samples/Kconfig9
-rw-r--r--samples/Makefile1
-rw-r--r--samples/coresight/Makefile4
-rw-r--r--samples/coresight/coresight-cfg-sample.c73
4 files changed, 87 insertions, 0 deletions
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");