[PATCH v8 24/24] coresight: allow the coresight core driver to be built as a module

Tingwei Zhang
2020-08-07T11:20:09Z

Enhance coresight developer's efficiency to debug coresight drivers.
- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to
be called coresight by the Makefile
- modules can have only one init/exit, so we add the etm_perf
register/unregister function calls to the core init/exit
functions.
- add a MODULE_DEVICE_TABLE for autoloading on boot

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/Kconfig | 5 ++-
drivers/hwtracing/coresight/Makefile | 5 ++-
.../{coresight.c => coresight-core.c} | 42 ++++++++++++++-----
.../hwtracing/coresight/coresight-etm-perf.c | 8 +++-
.../hwtracing/coresight/coresight-etm-perf.h | 3 ++
5 files changed, 48 insertions(+), 15 deletions(-)
rename drivers/hwtracing/coresight/{coresight.c => coresight-core.c} (98%)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index dfe407cde262..c1198245461d 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -3,7 +3,7 @@
# Coresight configuration
#
menuconfig CORESIGHT
- bool "CoreSight Tracing Support"
+ tristate "CoreSight Tracing Support"
depends on ARM || ARM64
depends on OF || ACPI
select ARM_AMBA
@@ -15,6 +15,9 @@ menuconfig CORESIGHT
specification and configure the right series of components when a
trace source gets enabled.

+ To compile this driver as a module, choose M here: the
+ module will be called coresight.
+
if CORESIGHT
config CORESIGHT_LINKS_AND_SINKS
tristate "CoreSight Link and Sink drivers"
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 0359d5a1588f..1b35b55bd420 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -2,8 +2,9 @@
#
# Makefile for CoreSight drivers.
#
-obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o \
- coresight-platform.o coresight-sysfs.o
+obj-$(CONFIG_CORESIGHT) += coresight.o
+coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \
+ coresight-sysfs.o
obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o
coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \
coresight-tmc-etr.o
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight-core.c
similarity index 98%
rename from drivers/hwtracing/coresight/coresight.c
rename to drivers/hwtracing/coresight/coresight-core.c
index f9566d667261..045416ac962f 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1462,16 +1462,6 @@ int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
}
EXPORT_SYMBOL_GPL(coresight_timeout);

-struct bus_type coresight_bustype = {
- .name = "coresight",
-};
-
-static int __init coresight_init(void)
-{
- return bus_register(&coresight_bustype);
-}
-postcore_initcall(coresight_init);
-
/*
* coresight_release_platform_data: Release references to the devices connected
* to the output port of this device.
@@ -1680,3 +1670,35 @@ char *coresight_alloc_device_name(struct coresight_dev_list *dict,
return name;
}
EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
+
+struct bus_type coresight_bustype = {
+ .name = "coresight",
+};
+
+static int __init coresight_init(void)
+{
+ int ret;
+
+ ret = bus_register(&coresight_bustype);
+ if (ret)
+ return ret;
+
+ ret = etm_perf_init();
+ if (ret)
+ bus_unregister(&coresight_bustype);
+
+ return ret;
+}
+
+static void __exit coresight_exit(void)
+{
+ etm_perf_exit();
+ bus_unregister(&coresight_bustype);
+}
+
+module_init(coresight_init);
+module_exit(coresight_exit);
+
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight tracer driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 3728c44e5763..668b3ff11576 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -591,7 +591,7 @@ void etm_perf_del_symlink_sink(struct coresight_device *csdev)
csdev->ea = NULL;
}

-static int __init etm_perf_init(void)
+int __init etm_perf_init(void)
{
int ret;

@@ -618,4 +618,8 @@ static int __init etm_perf_init(void)

return ret;
}
-device_initcall(etm_perf_init);
+
+void __exit etm_perf_exit(void)
+{
+ perf_pmu_unregister(&etm_pmu);
+}
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
index 05f89723e282..3e4f2ad5e193 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.h
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
@@ -82,4 +82,7 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle)

#endif /* CONFIG_CORESIGHT */

+int __init etm_perf_init(void);
+void __exit etm_perf_exit(void);
+
#endif
--
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