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 && mhelpBuild an example loadable module that adds new CoreSight featuresand configuration using the CoreSight system configuration API.This demonstrates how a user may create their own CoreSightconfigurations 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