[PATCH v6 25/25] coresight: allow the coresight core driver to be built as a module

[Mike Leach]

On Fri, 31 Jul 2020 at 07:42, Tingwei Zhang <tingwei at codeaurora.org> wrote:
>
> 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 at linaro.org>
> Cc: Leo Yan <leo.yan at linaro.org>
> Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
> Cc: Randy Dunlap <rdunlap at infradead.org>
> Cc: Suzuki K Poulose <Suzuki.Poulose at arm.com>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Russell King <linux at armlinux.org.uk>
> Signed-off-by: Kim Phillips <kim.phillips at arm.com>
> Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
> ---
>  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 3b4abdda1f72..5cd200031613 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -1444,16 +1444,6 @@ 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.
> @@ -1662,3 +1652,35 @@ 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 at 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
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>

Tested by: Mike Leach <mike.leach at linaro.org>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK