On 5 June 2018 at 15:07, Kim Phillips <[email protected]> wrote:
> Allow to build coresight as a module. This enhances
> coresight developer efficiency by allowing the development to
> take place exclusively on the target, and without needing to
> reboot in between changes.
>
> - 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 core bus
> register/unregister function calls to the etm_perf init/exit
> functions, since coresight.c does not have etm_pmu defined.
> - add a MODULE_DEVICE_TABLE for autoloading on boot
>
> Cc: Mathieu Poirier <[email protected]>
> Cc: Leo Yan <[email protected]>
> Cc: Alexander Shishkin <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Suzuki K Poulose <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Russell King <[email protected]>
> Signed-off-by: Kim Phillips <[email protected]>
> ---
> drivers/hwtracing/coresight/Kconfig | 5 ++++-
> drivers/hwtracing/coresight/Makefile | 7 +++++--
> .../coresight/{coresight.c => coresight-core.c} | 6 ------
> .../hwtracing/coresight/coresight-etm-perf.c | 17 ++++++++++++++++-
> 4 files changed, 25 insertions(+), 10 deletions(-)
> rename drivers/hwtracing/coresight/{coresight.c => coresight-core.c} (99%)
>
> diff --git a/drivers/hwtracing/coresight/Kconfig
> b/drivers/hwtracing/coresight/Kconfig
> index 181a44ea2d61..c05b265f7731 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -2,7 +2,7 @@
> # Coresight configuration
> #
> menuconfig CORESIGHT
> - bool "CoreSight Tracing Support"
> + tristate "CoreSight Tracing Support"
> select ARM_AMBA
> select PERF_EVENTS
> help
> @@ -12,6 +12,9 @@ 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 45d7a0f34170..ed2d4bcb017b 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -2,8 +2,11 @@
> #
> # Makefile for CoreSight drivers.
> #
> -obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o
> -obj-$(CONFIG_OF) += of_coresight.o
> +obj-$(CONFIG_CORESIGHT) += coresight.o
> +coresight-objs := coresight-core.o coresight-etm-perf.o
> +ifeq ($(CONFIG_OF), y)
> +coresight-objs += of_coresight.o
> +endif
> obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o
> coresight-tmc-objs := 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 99%
> rename from drivers/hwtracing/coresight/coresight.c
> rename to drivers/hwtracing/coresight/coresight-core.c
> index 1c941351f1d1..f96258de1e9b 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -948,12 +948,6 @@ struct bus_type coresight_bustype = {
> .name = "coresight",
> };
>
> -static int __init coresight_init(void)
> -{
> - return bus_register(&coresight_bustype);
> -}
> -postcore_initcall(coresight_init);
> -
> struct coresight_device *coresight_register(struct coresight_desc *desc)
> {
> int i;
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c
> b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 0fe7e43ea1c4..ceac9aee4a82 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -472,6 +472,10 @@ static int __init etm_perf_init(void)
> {
> int ret;
>
> + ret = bus_register(&coresight_bustype);
> + if (ret)
> + return ret;
> +
> etm_pmu.capabilities = PERF_PMU_CAP_EXCLUSIVE;
>
> etm_pmu.attr_groups = etm_pmu_attr_groups;
> @@ -494,4 +498,15 @@ static int __init etm_perf_init(void)
>
> return ret;
> }
> -device_initcall(etm_perf_init);
> +postcore_initcall(etm_perf_init);
> +
> +static void __exit etm_perf_exit(void)
> +{
> + perf_pmu_unregister(&etm_pmu);
> + bus_unregister(&coresight_bustype);
> +}
> +module_exit(etm_perf_exit);
I see the perf functionality as an accessory to the core rather than
the other way around. Initialisation in the core code should be
driving the PMU registration.
> +
> +MODULE_AUTHOR("Mathieu Poirier <[email protected]>");
> +MODULE_DESCRIPTION("Arm CoreSight tracer driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.0
>
