Re: [PATCHv3 0/5] arm-cci400: PMU monitoring support on ARM64

[Suzuki K. Poulose]

On 10/03/15 16:09, Nicolas Pitre wrote:
> On Tue, 10 Mar 2015, Suzuki K. Poulose wrote:
>
> > From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx>
> >
> > 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.
>
> Would be nice if you could also test it on secure TC2 making sure MCPM
> is still functional.

Sudeep is testing those bits.
> For patches 1, 3 and 4, you may add:
>
> Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>
>
> Patches 2 and 5 are purely PMU stuff and out of my area of expertise.

Thanks
Suzuki


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