Re: [PATCH V8 22/23] perf tools: making coresight PMU listable

[Mathieu Poirier]

On 14 January 2016 at 14:46, Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> wrote:
> Adding the required mechanic allowing 'perf list pmu' to
> discover coresight ETM/PTM tracers.
>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
>  MAINTAINERS                    |  1 +
>  tools/perf/arch/arm/util/Build |  2 ++
>  tools/perf/arch/arm/util/pmu.c | 34 ++++++++++++++++++++++++++++++++++
>  tools/perf/config/Makefile     | 17 ++++++++++++-----
>  4 files changed, 49 insertions(+), 5 deletions(-)
>  create mode 100644 tools/perf/arch/arm/util/pmu.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 233f83464814..b2a92245eece 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1007,6 +1007,7 @@ F:        drivers/hwtracing/coresight/*
>  F:     Documentation/trace/coresight.txt
>  F:     Documentation/devicetree/bindings/arm/coresight.txt
>  F:     Documentation/ABI/testing/sysfs-bus-coresight-devices-*
> +F:     tools/perf/arch/arm/util/pmu.c
>
>  ARM/CORGI MACHINE SUPPORT
>  M:     Richard Purdie <rpurdie@xxxxxxxxx>
> diff --git a/tools/perf/arch/arm/util/Build b/tools/perf/arch/arm/util/Build
> index d22e3d07de3d..66ab0b05549c 100644
> --- a/tools/perf/arch/arm/util/Build
> +++ b/tools/perf/arch/arm/util/Build
> @@ -2,3 +2,5 @@ libperf-$(CONFIG_DWARF) += dwarf-regs.o
>
>  libperf-$(CONFIG_LIBUNWIND)          += unwind-libunwind.o
>  libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
> +
> +libperf-$(CONFIG_AUXTRACE) += pmu.o
> diff --git a/tools/perf/arch/arm/util/pmu.c b/tools/perf/arch/arm/util/pmu.c
> new file mode 100644
> index 000000000000..af9fb666b44f
> --- /dev/null
> +++ b/tools/perf/arch/arm/util/pmu.c
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright(C) 2015 Linaro Limited. All rights reserved.
> + * Author: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <string.h>
> +#include <linux/coresight-pmu.h>
> +#include <linux/perf_event.h>
> +
> +#include "../../util/pmu.h"
> +
> +struct perf_event_attr
> +*perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
> +{
> +#ifdef HAVE_AUXTRACE_SUPPORT
> +       if (!strcmp(pmu->name, CORESIGHT_ETM_PMU_NAME)) {
> +               /* add ETM default config here */
> +               pmu->selectable = true;
> +       }
> +#endif
> +       return NULL;
> +}
> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
> index de89ec574361..905faabff8b1 100644
> --- a/tools/perf/config/Makefile
> +++ b/tools/perf/config/Makefile
> @@ -647,12 +647,19 @@ ifdef LIBBABELTRACE
>  endif
>
>  ifndef NO_AUXTRACE
> -  ifeq ($(feature-get_cpuid), 0)
> -    msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
> -    NO_AUXTRACE := 1
> +  ifeq ($(ARCH),x86)
> +    ifeq ($(feature-get_cpuid), 0)
> +      msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
> +      NO_AUXTRACE := 1
> +    else
> +      $(call detected,CONFIG_AUXTRACE)
> +      CFLAGS += -DHAVE_AUXTRACE_SUPPORT
> +    endif
>    else
> -    $(call detected,CONFIG_AUXTRACE)
> -    CFLAGS += -DHAVE_AUXTRACE_SUPPORT
> +    ifeq ($(ARCH),$(filter $(ARCH), arm arm64))
> +      $(call detected,CONFIG_AUXTRACE)
> +      CFLAGS += -DHAVE_AUXTRACE_SUPPORT
> +    endif
>    endif
>  endif
>
> --
> 2.1.4
>

Arnaldo,

This is the third (of four) patch that I can't queue without a
reviewed by from you.

It has been rebased to 4.5-rc1 here [1] for your convenience.  I will
be happy to use another baseline should that be more adequate for you.

Thanks,
Mathieu

[1]. https://git.linaro.org/people/mathieu.poirier/coresight.git/shortlog/refs/heads/perf-v4.5-rc1-V8