Messages in this thread | | | Date | Tue, 17 May 2011 20:13:53 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH 1/5] acpi-cpufreq: Add support for modern AMD CPUs |
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+ Andreas.
On Tue, May 17, 2011 at 06:42:33PM +0100, Matthew Garrett wrote: > > Ok, I'm a bit confused here but maybe because I don't know the whole > > cpufreq subsystem that well. Is the purpose here to add hw pstates > > support to acpi-cpufreq so that it is used on AMD but leave the old > > Fid/Vid method to powernow-k8, thus phasing it out...? > > Yes. The last patch in the set removes the hw pstate code from > powernow-k8.
Ok, good. The diffstat of 5/5 talks for itself but let's see what the others have to say first. Obviously, these changes need to be tested very thoroughly on a bunch of machines before we go forth with them.
> > > #define MSR_IA32_PERF_STATUS 0x00000198 > > > #define MSR_IA32_PERF_CTL 0x00000199 > > > +#define MSR_AMD_PERF_STATUS 0xc0010063 > > > +#define MSR_AMD_PERF_CTL 0xc0010062 > > > > Yeah, there are defines for those in > > <arch/x86/kernel/cpu/cpufreq/powernow-k8.h>: > > > > #define MSR_PSTATE_STATUS 0xc0010063 /* Pstate Status MSR */ > > #define MSR_PSTATE_CTRL 0xc0010062 /* Pstate control MSR */ > > > > can you remove them from there for consistency so that we can use only > > the msr-index.h definitions. > > That happens in the final patch.
Maybe I should read the whole patchset first :).
> > > > +static int check_powernow_cpu(unsigned int cpuid) > > > +{ > > > + struct cpuinfo_x86 *cpu = &cpu_data(cpuid); > > > + > > > + return cpu_has(cpu, X86_FEATURE_POWERNOW); > > > +} > > > > This could be static_cpu_has() since all the CPUs, including the boot > > CPU, will have the HwPstate thing set. Thus, you can ignore the "cpuid" > > parameter. > > Ok, this was just for symmetry with the est version.
Right, but I don't think that would be different on Intel and static_cpu_has is faster with the alternatives mechanism anyway.
Thanks.
-- Regards/Gruss, Boris.
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