coresight: core: Allow the coresight core driver to be built as a module

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>
Tested-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-25-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 47894a0dcf5e..c2c9b127d074 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -599,7 +599,7 @@ 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;
 
@@ -626,4 +626,8 @@ 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);
+}