[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] cpufreq implementation for OMAP under xen hypervisor.

Hi to all.

I'm planning to do next work:

1. Move file xen/include/acpi/cpufreq/cpufreq.h to the
2. Create a new file xen/arch/x86/acpi/cpufreq/cpufreq_common.c
3. Move some acpi-specific functions from
xen/drivers/cpufreq/cpufreq.c to the
cpufreq_limit_change(), print_PCT(), print_PSS(), print_PSD(),
print_PPC(), set_px_pminfo().
4. Create a new file xen/arch/arm/cpufreq/cpufreq_common.c
5. Functions cpufreq_add_cpu()/cpufreq_del_cpu() should be implemented
separately for the x86 and ARM architecture (in the correspond file
6. Port cpufreq driver for the OMAP from the Linux kernel.

In case ARM the cpufreq driver will read the settings for the
operating-points from the device tree and the
XENPF_set_processor_pminfo platform hypercall will not be necessary
for ARM.

Is this the right way to implement the cpufreq for OMAP under xen hypervisor?

Oleksandr Dmytryshyn | Product Engineering and Development
M +38.067.382.2525


On Tue, Aug 12, 2014 at 3:15 PM, Stefano Stabellini
<stefano.stabellini@xxxxxxxxxxxxx> wrote:
> On Tue, 12 Aug 2014, Oleksandr Dmytryshyn wrote:
>> Hi to all.
>> I want to implement an cpufreq support for OMAP processors in xen. I
>> use the Linux kernel as Dom0.
>> I know that there are 2 implementations of cpufreq: Domain0 based
>> cpufreq and Hypervisor based cpufreq. But those implementations are
>> made only for x86 architecture, not for the ARM architecture.
>> Could anybody give me an advise how to do that?
> I think that the best way would be to introduce cpufreq support directly
> in the Xen hypervisor.  I would:
> 1) get cpufreq (xen/drivers/cpufreq) to build and run on ARM, with a dummy 
> driver
> although the cpufreq infrastructure has been written with x86 in mind,
> it should be generalizable
> 2) write a cpufreq driver for OMAP

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.