From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 5/5] arm-cci: Fix CCI PMU event validation
Date: Tue, 17 Mar 2015 18:52:47 +0000 [thread overview]
Message-ID: <20150317185247.GE8399@arm.com> (raw)
In-Reply-To: <1426000735-14375-6-git-send-email-suzuki.poulose@arm.com>
On Tue, Mar 10, 2015 at 03:18:55PM +0000, Suzuki K. Poulose wrote:
> From: "Suzuki K. Poulose" <suzuki.poulose@arm•com>
>
> We mask the event with the CCI_PMU_EVENT_MASK, before passing
> the config to pmu_validate_hw_event(), which causes extra bits
> to be ignored and qualifies an invalid event code as valid.
>
> e.g,
> $ perf stat -a -C 0 -e CCI_400/config=0x1ff,name=cycles/ sleep 1
> Performance counter stats for 'system wide':
>
> 506951142 cycles
>
> 1.013879626 seconds time elapsed
>
> where, cycles has an event coding of 0xff. This patch also removes
> the unnecessary 'event' mask in pmu_write_register, since the config_base
> is set by the pmu code after the event is validated.
>
> Changes since V2:
> - Switch to input unsigned long for pmu_validate_hw_event()
>
> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm•com>
> ---
> drivers/bus/arm-cci.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
> index 581190d..89c86e9 100644
> --- a/drivers/bus/arm-cci.c
> +++ b/drivers/bus/arm-cci.c
> @@ -179,12 +179,15 @@ enum cci400_perf_events {
> #define CCI_REV_R1_MASTER_PORT_MIN_EV 0x00
> #define CCI_REV_R1_MASTER_PORT_MAX_EV 0x11
>
> -static int pmu_validate_hw_event(u8 hw_event)
> +static int pmu_validate_hw_event(unsigned long hw_event)
> {
> u8 ev_source = CCI_PMU_EVENT_SOURCE(hw_event);
> u8 ev_code = CCI_PMU_EVENT_CODE(hw_event);
> int if_type;
>
> + if (hw_event & ~CCI_PMU_EVENT_MASK)
> + return -ENOENT;
Given that you want to build this for arm64, shouldn't CCI_PMU_EVENT_MASK
be an unsigned long too (i.e. 0xffUL)? Otherwise you won't detect set bits
in the upper word here.
Will
next prev parent reply other threads:[~2015-03-17 18:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-10 15:18 [PATCHv3 0/5] arm-cci400: PMU monitoring support on ARM64 Suzuki K. Poulose
2015-03-10 15:18 ` [PATCH 1/5] arm-cci: Rearrange code for splitting PMU vs driver code Suzuki K. Poulose
2015-03-10 15:18 ` [PATCH 2/5] arm-cci: Abstract the CCI400 PMU speicific definitions Suzuki K. Poulose
2015-03-17 18:49 ` Will Deacon
2015-03-10 15:18 ` [PATCH 3/5] arm-cci: Get rid of secure transactions for PMU driver Suzuki K. Poulose
2015-03-17 9:51 ` [UPDATED] " Suzuki K. Poulose
2015-03-19 17:25 ` Mark Rutland
2015-03-19 17:32 ` Mark Rutland
2015-03-19 17:38 ` Sudeep Holla
2015-03-19 17:52 ` Suzuki K. Poulose
2015-03-19 17:54 ` Mark Rutland
2015-03-10 15:18 ` [PATCH 4/5] arm-cci: Split the code for PMU vs driver support Suzuki K. Poulose
2015-03-10 16:24 ` Sudeep Holla
2015-03-10 15:18 ` [PATCH 5/5] arm-cci: Fix CCI PMU event validation Suzuki K. Poulose
2015-03-17 18:52 ` Will Deacon [this message]
2015-03-10 16:09 ` [PATCHv3 0/5] arm-cci400: PMU monitoring support on ARM64 Nicolas Pitre
2015-03-10 16:11 ` Suzuki K. Poulose
2015-03-10 16:21 ` Sudeep Holla
2015-03-10 16:24 ` Suzuki K. Poulose
2015-03-11 11:40 ` Punit Agrawal
2015-03-17 18:54 ` Will Deacon
2015-03-18 10:09 ` Suzuki K. Poulose
-- strict thread matches above, loose matches on Subject: below --
2015-03-02 11:29 [PATCH v2 " Suzuki K. Poulose
2015-03-02 11:29 ` [PATCH 5/5] arm-cci: Fix CCI PMU event validation Suzuki K. Poulose
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