From mboxrd@z Thu Jan 1 00:00:00 1970 From: pawel.moll@arm.com (Pawel Moll) Date: Mon, 22 Aug 2016 15:10:46 +0100 Subject: [PATCHv2] arm: l2x0: add PMU support In-Reply-To: <1471602346-26466-1-git-send-email-mark.rutland@arm.com> References: <1471602346-26466-1-git-send-email-mark.rutland@arm.com> Message-ID: <1471875046.5473.11.camel@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 2016-08-19 at 11:25 +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 > Tested-by: Kim Phillips > Cc: Pawel Moll > Cc: Russell King > Cc: Will Deacon For what it's worth, it's enthusiastically Acked-by: Pawel Moll Thanks! Pawel