From mboxrd@z Thu Jan 1 00:00:00 1970 From: Punit Agrawal Subject: Re: [PATCHv3 0/5] arm-cci400: PMU monitoring support on ARM64 Date: Wed, 11 Mar 2015 11:40:16 +0000 Message-ID: <9hhsidbyd7j.fsf@e105922-lin.cambridge.arm.com> References: <1426000735-14375-1-git-send-email-suzuki.poulose@arm.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1426000735-14375-1-git-send-email-suzuki.poulose-5wv7dgnIgG8@public.gmane.org> (Suzuki K. Poulose's message of "Tue, 10 Mar 2015 15:18:50 +0000") Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Suzuki K. Poulose" Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Nicolas Pitre , Bartlomiej Zolnierkiewicz , Kukjin Kim , Abhilash Kesavan , Arnd Bergmann , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Liviu Dudau , Lorenzo Pieralisi , Olof Johansson , Pawel Moll , Sudeep Holla , Will Deacon , Catalin Marinas List-Id: devicetree@vger.kernel.org "Suzuki K. Poulose" writes: > From: "Suzuki K. Poulose" > > This series enables the PMU monitoring support for CCI400 on ARM64. > The existing CCI400 driver code is a mix of PMU driver and the MCPM > driver code. The MCPM driver is only used on ARM(32) and contains > arm32 assembly and hence can't be built on ARM64. This patch splits > the code to > > - ARM_CCI400_PORT_CTRL driver - depends on ARM && V7 > - ARM_CCI400_PMU driver > > Accessing the Peripheral ID2 register(PID2) on CCI-400, to detect > the revision of the chipset, is a secure operation. Hence, it prevents > us from running this on non-secure platforms. The issue is overcome by > explicitly mentioning the revision number of the CCI PMU in the device tree > binding. The device-tree binding has been updated with the new bindings. > > i.e, arm-cci-400-pmu,r0 => revision 0 > arm-cci-400-pmu,r1 => revision 1 > arm-cci-400-pmu => (old) DEPRECATED > > The old binding has been DEPRECATED and must be used only on ARM32 > system with secure access. We don't have a reliable dynamic way to detect > if the system is running secure. This series tries to use the best safe > method by relying on the availability of MCPM(as it was prior to the series). > It is upto the MCPM platform driver to decide, if the system is secure before > it goes ahead and registers its drivers and pokes the CCI. This series doesn't > address/solve the problem of MCPM. I will be happy to use a better approach, > if there is any. > > Tested on (non-secure)TC2 and A53x2. > For the series, Acked-by: Punit Agrawal Cheers, Punit [...] -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html