Messages in this thread | | | From | Mathieu Poirier <> | Date | Thu, 7 Jun 2018 15:46:53 -0600 | Subject | Re: [PATCH v4 14/14] coresight: allow the coresight core driver to be built as a module |
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On 5 June 2018 at 15:07, Kim Phillips <kim.phillips@arm.com> 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 <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> > --- > 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 <mathieu.poirier@linaro.org>"); > +MODULE_DESCRIPTION("Arm CoreSight tracer driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.17.0 >
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