From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Fri, 19 Aug 2016 11:33:50 +0100 Subject: [PATCH] arm: l2x0: add PMU support In-Reply-To: <20160818190546.3c81388f8bd6d311bd28207c@arm.com> References: <1471451191-18090-1-git-send-email-mark.rutland@arm.com> <20160818190546.3c81388f8bd6d311bd28207c@arm.com> Message-ID: <20160819103349.GA25541@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 18, 2016 at 07:05:46PM -0500, Kim Phillips wrote: > On Wed, 17 Aug 2016 17:26:31 +0100 > Mark Rutland wrote: > > > The L2C-220 (AKA L220) and L2C-310 (AKA PL310) cache controllers feature > > a Performance Monitoring Unit (PMU), which can be useful for tuning > > and/or debugging. This hardware is always present and the relevant > > registers are accessible to non-secure accesses. Thus, no special > > firmware interface is necessary. > > > > This patch adds support for the PMU, plugging into the usual perf > > infrastructure. The overflow interrupt is not always available (e.g. on > > RealView PBX A9 it is not wired up at all), and the hardware counters > > saturate, so the driver does not make use of this. Instead, the driver > > periodically polls and reset counters as required to avoid losing > > events due to saturation. > > > > Signed-off-by: Mark Rutland > > Cc: Kim Phillips > > Cc: Pawel Moll > > Cc: Russell King > > Cc: Will Deacon > > --- > > FWIW, I was able to test this successfully on a pandaboard. Great! I've taken that as a Tested-by for v2 of the series [1], on the assumption that you're happy with that. Please give me a shout if that is not the case! Thanks, Mark. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/450024.html