Re: [PATCH v6 10/25] coresight: etm4x: allow etm4x to be built as a module

[Mike Leach <mike.leach@linaro.org>]

On Fri, 31 Jul 2020 at 07:41, Tingwei Zhang <tingwei@codeaurora.org> wrote:
>
> From: Kim Phillips <kim.phillips@arm.com>
>
> Allow to build coresight-etm4x as a module, for ease of development.
>
> - Kconfig becomes a tristate, to allow =m
> - append -core to source file name to allow module to
>   be called coresight-etm4x by the Makefile
> - add an etm4_remove function, for module unload
> - 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>
> ---
>  drivers/hwtracing/coresight/Kconfig           |  5 +++-
>  drivers/hwtracing/coresight/Makefile          |  4 +--
>  ...resight-etm4x.c => coresight-etm4x-core.c} | 26 ++++++++++++++++++-
>  3 files changed, 31 insertions(+), 4 deletions(-)
>  rename drivers/hwtracing/coresight/{coresight-etm4x.c => coresight-etm4x-core.c} (98%)
>
> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> index 8fd9fd139cf3..d6e107bbd30b 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -78,7 +78,7 @@ config CORESIGHT_SOURCE_ETM3X
>           module will be called coresight-etm3x.
>
>  config CORESIGHT_SOURCE_ETM4X
> -       bool "CoreSight Embedded Trace Macrocell 4.x driver"
> +       tristate "CoreSight Embedded Trace Macrocell 4.x driver"
>         depends on ARM64
>         select CORESIGHT_LINKS_AND_SINKS
>         select PID_IN_CONTEXTIDR
> @@ -88,6 +88,9 @@ config CORESIGHT_SOURCE_ETM4X
>           for instruction level tracing. Depending on the implemented version
>           data tracing may also be available.
>
> +         To compile this driver as a module, choose M here: the
> +         module will be called coresight-etm4x.
> +
>  config CORESIGHT_STM
>         tristate "CoreSight System Trace Macrocell driver"
>         depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64
> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> index d619cfd0abd8..271dc255454f 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -14,8 +14,8 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
>  obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o
>  coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \
>                                         coresight-etm3x-sysfs.o
> -obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
> -                                       coresight-etm4x-sysfs.o
> +obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o
> +coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o
>  obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
>  obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
>  obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> similarity index 98%
> rename from drivers/hwtracing/coresight/coresight-etm4x.c
> rename to drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 6d7d2169bfb2..8149853d5e9d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -1573,6 +1573,21 @@ static struct amba_cs_uci_id uci_id_etm4[] = {
>         }
>  };
>
> +static int __exit etm4_remove(struct amba_device *adev)
> +{
> +       struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);
> +
> +       etm_perf_symlink(drvdata->csdev, false);
> +
> +       etmdrvdata[drvdata->cpu] = NULL;
> +       etm4_pm_clear();
> +
> +       coresight_unregister(drvdata->csdev);
> +
> +       return 0;
> +}
> +
> +
>  static const struct amba_id etm4_ids[] = {
>         CS_AMBA_ID(0x000bb95d),                 /* Cortex-A53 */
>         CS_AMBA_ID(0x000bb95e),                 /* Cortex-A57 */
> @@ -1590,12 +1605,21 @@ static const struct amba_id etm4_ids[] = {
>         {},
>  };
>
> +MODULE_DEVICE_TABLE(amba, etm4_ids);
> +
>  static struct amba_driver etm4x_driver = {
>         .drv = {
>                 .name   = "coresight-etm4x",
> +               .owner  = THIS_MODULE,
>                 .suppress_bind_attrs = true,
>         },
>         .probe          = etm4_probe,
> +       .remove         = etm4_remove,
>         .id_table       = etm4_ids,
>  };
> -builtin_amba_driver(etm4x_driver);
> +module_amba_driver(etm4x_driver);
> +
> +MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
> +MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
> +MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4 driver");
> +MODULE_LICENSE("GPL v2");
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>

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

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

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