From: Will Deacon <will@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@redhat.com>, Mark Rutland <mark.rutland@arm.com>,
Ian Rogers <irogers@google.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
honnappa.nagarahalli@arm.com, Zachary.Leaf@arm.com,
Raphael Gault <raphael.gault@arm.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Namhyung Kim <namhyung@kernel.org>,
Itaru Kitayama <itaru.kitayama@gmail.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 01/10] arm64: pmu: Add function implementation to update event index in userpage
Date: Tue, 30 Mar 2021 16:30:37 +0100 [thread overview]
Message-ID: <20210330153036.GA6567@willie-the-truck> (raw)
In-Reply-To: <20210311000837.3630499-2-robh@kernel.org>
On Wed, Mar 10, 2021 at 05:08:28PM -0700, Rob Herring wrote:
> From: Raphael Gault <raphael.gault@arm.com>
>
> In order to be able to access the counter directly for userspace,
> we need to provide the index of the counter using the userpage.
> We thus need to override the event_idx function to retrieve and
> convert the perf_event index to armv8 hardware index.
>
> Since the arm_pmu driver can be used by any implementation, even
> if not armv8, two components play a role into making sure the
> behaviour is correct and consistent with the PMU capabilities:
>
> * the ARMPMU_EL0_RD_CNTR flag which denotes the capability to access
> counter from userspace.
> * the event_idx call back, which is implemented and initialized by
> the PMU implementation: if no callback is provided, the default
> behaviour applies, returning 0 as index value.
>
> Signed-off-by: Raphael Gault <raphael.gault@arm.com>
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> arch/arm64/kernel/perf_event.c | 18 ++++++++++++++++++
> include/linux/perf/arm_pmu.h | 2 ++
> 2 files changed, 20 insertions(+)
Acked-by: Will Deacon <will@kernel.org>
Will
next prev parent reply other threads:[~2021-03-30 15:31 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 0:08 [PATCH v6 00/10] libperf and arm64 userspace counter access support Rob Herring
2021-03-11 0:08 ` [PATCH v6 01/10] arm64: pmu: Add function implementation to update event index in userpage Rob Herring
2021-03-30 15:30 ` Will Deacon [this message]
2021-03-11 0:08 ` [PATCH v6 02/10] arm64: perf: Enable PMU counter direct access for perf event Rob Herring
2021-03-30 11:30 ` Zachary Leaf
2021-03-30 15:31 ` Will Deacon
2021-03-30 17:09 ` Rob Herring
2021-03-30 21:08 ` Rob Herring
2021-03-31 15:38 ` Will Deacon
2021-03-31 17:52 ` Rob Herring
2021-04-01 9:04 ` Will Deacon
2021-03-31 16:00 ` Will Deacon
2021-04-01 19:45 ` Rob Herring
2021-04-07 12:44 ` Will Deacon
2021-04-08 11:08 ` Mark Rutland
2021-04-08 18:38 ` Rob Herring
2021-04-19 16:14 ` Will Deacon
2021-04-19 19:00 ` Rob Herring
2021-03-11 0:08 ` [PATCH v6 03/10] tools/include: Add an initial math64.h Rob Herring
2021-03-11 0:08 ` [PATCH v6 04/10] libperf: Add evsel mmap support Rob Herring
2021-03-12 13:58 ` Jiri Olsa
2021-03-12 14:34 ` Rob Herring
2021-03-12 18:29 ` Jiri Olsa
2021-03-31 22:06 ` Rob Herring
2021-03-11 0:08 ` [PATCH v6 05/10] libperf: tests: Add support for verbose printing Rob Herring
2021-03-11 0:08 ` [PATCH v6 06/10] libperf: Add support for user space counter access Rob Herring
2021-05-04 21:40 ` Ian Rogers
2021-05-05 2:12 ` Rob Herring
2021-03-11 0:08 ` [PATCH v6 07/10] libperf: Add arm64 support to perf_mmap__read_self() Rob Herring
2021-03-11 0:08 ` [PATCH v6 08/10] perf: arm64: Add test for userspace counter access on heterogeneous systems Rob Herring
2021-03-15 16:09 ` Masayoshi Mizuma
2021-03-11 0:08 ` [PATCH v6 09/10] perf: arm64: Add tests for 32-bit and 64-bit counter size userspace access Rob Herring
2021-03-11 0:08 ` [PATCH v6 10/10] Documentation: arm64: Document PMU counters access from userspace Rob Herring
2021-03-31 16:00 ` Will Deacon
2021-03-30 11:31 ` [PATCH v6 00/10] libperf and arm64 userspace counter access support Zachary Leaf
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