cpufreq: Add APERF/MPERF support for AMD processors
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From: Thomas Renninger on 23 Mar 2010 07:30 On Monday 22 March 2010 19:38:39 Borislav Petkov wrote: > From: Mark Langsdorf <mark.langsdorf(a)amd.com> > > Starting with model 10 of Family 0x10, AMD processors may have > support for APERF/MPERF. Add support for identifying it and using > it within cpufreq. Move the APERF/MPERF functions out of the > acpi-cpufreq code and into their own file so they can easily be > shared. > > Signed-off-by: Mark Langsdorf <mark.langsdorf(a)amd.com> > Signed-off-by: Borislav Petkov <borislav.petkov(a)amd.com> > --- > arch/x86/kernel/cpu/amd.c | 6 +++ > arch/x86/kernel/cpu/cpufreq/Makefile | 4 +- > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 44 +----------------------- > arch/x86/kernel/cpu/cpufreq/mperf.c | 50 ++++++++++++++++++++++++++++ > arch/x86/kernel/cpu/cpufreq/mperf.h | 9 +++++ > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 8 ++++ > 6 files changed, 77 insertions(+), 44 deletions(-) > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h > > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > index e485825..796f662 100644 > --- a/arch/x86/kernel/cpu/amd.c > +++ b/arch/x86/kernel/cpu/amd.c > @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); > } > > + if (c->cpuid_level >= 6) { > + unsigned ecx = cpuid_ecx(6); > + if (ecx & 0x01) > + set_cpu_cap(c, X86_FEATURE_APERFMPERF); > + } This is nearly identical to (beside c->cpuid_level > 6), in arch/x86/kernel/cpu/intel.c: if (c->cpuid_level > 6) { unsigned ecx = cpuid_ecx(6); if (ecx & 0x01) set_cpu_cap(c, X86_FEATURE_APERFMPERF); } I expect you are correct... or could it get moved to general x86 init code? Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Borislav Petkov on 23 Mar 2010 08:00 From: Thomas Renninger <trenn(a)suse.de> Date: Tue, Mar 23, 2010 at 12:26:22PM +0100 > On Monday 22 March 2010 19:38:39 Borislav Petkov wrote: > > From: Mark Langsdorf <mark.langsdorf(a)amd.com> > > > > Starting with model 10 of Family 0x10, AMD processors may have > > support for APERF/MPERF. Add support for identifying it and using > > it within cpufreq. Move the APERF/MPERF functions out of the > > acpi-cpufreq code and into their own file so they can easily be > > shared. > > > > Signed-off-by: Mark Langsdorf <mark.langsdorf(a)amd.com> > > Signed-off-by: Borislav Petkov <borislav.petkov(a)amd.com> > > --- > > arch/x86/kernel/cpu/amd.c | 6 +++ > > arch/x86/kernel/cpu/cpufreq/Makefile | 4 +- > > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 44 +----------------------- > > arch/x86/kernel/cpu/cpufreq/mperf.c | 50 ++++++++++++++++++++++++++++ > > arch/x86/kernel/cpu/cpufreq/mperf.h | 9 +++++ > > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 8 ++++ > > 6 files changed, 77 insertions(+), 44 deletions(-) > > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c > > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h > > > > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > > index e485825..796f662 100644 > > --- a/arch/x86/kernel/cpu/amd.c > > +++ b/arch/x86/kernel/cpu/amd.c > > @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > > set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); > > } > > > > + if (c->cpuid_level >= 6) { > > + unsigned ecx = cpuid_ecx(6); > > + if (ecx & 0x01) > > + set_cpu_cap(c, X86_FEATURE_APERFMPERF); > > + } > This is nearly identical to (beside c->cpuid_level > 6), > in arch/x86/kernel/cpu/intel.c: > if (c->cpuid_level > 6) { > unsigned ecx = cpuid_ecx(6); > if (ecx & 0x01) > set_cpu_cap(c, X86_FEATURE_APERFMPERF); > } > I expect you are correct... or could it get moved to general x86 init code? Sounds good... -- Regards/Gruss, Boris. -- Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Thomas Renninger on 25 Mar 2010 05:50 On Wednesday 24 March 2010 18:46:21 Borislav Petkov wrote: > From: Mark Langsdorf <mark.langsdorf(a)amd.com> > > Starting with model 10 of Family 0x10, AMD processors may have > support for APERF/MPERF. Add support for identifying it and using > it within cpufreq. Move the APERF/MPERF functions out of the > acpi-cpufreq code and into their own file so they can easily be > shared. > > Signed-off-by: Mark Langsdorf <mark.langsdorf(a)amd.com> > Signed-off-by: Borislav Petkov <borislav.petkov(a)amd.com> > --- > arch/x86/kernel/cpu/amd.c | 6 +++ > arch/x86/kernel/cpu/cpufreq/Makefile | 4 +- > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 44 +----------------------- > arch/x86/kernel/cpu/cpufreq/mperf.c | 50 ++++++++++++++++++++++++++++ > arch/x86/kernel/cpu/cpufreq/mperf.h | 9 +++++ > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 8 ++++ > 6 files changed, 77 insertions(+), 44 deletions(-) > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h > > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > index e485825..796f662 100644 > --- a/arch/x86/kernel/cpu/amd.c > +++ b/arch/x86/kernel/cpu/amd.c > @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); > } > > + if (c->cpuid_level >= 6) { > + unsigned ecx = cpuid_ecx(6); > + if (ecx & 0x01) > + set_cpu_cap(c, X86_FEATURE_APERFMPERF); > + } > + Can you put this into: arch/x86/kernel/cpu/common.c (or wherever it fits in general x86 cpu init code) and remove this (arch/x86/kernel/cpu/intel.c): if (c->cpuid_level > 6) { unsigned ecx = cpuid_ecx(6); if (ecx & 0x01) set_cpu_cap(c, X86_FEATURE_APERFMPERF); } an x86 maintainer might want to double check, but I expect this should work for all x86 machines? Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Borislav Petkov on 25 Mar 2010 07:10 From: Thomas Renninger <trenn(a)suse.de> Date: Thu, Mar 25, 2010 at 10:43:04AM +0100 Hi Thomas, > On Wednesday 24 March 2010 18:46:21 Borislav Petkov wrote: > > From: Mark Langsdorf <mark.langsdorf(a)amd.com> > > > > Starting with model 10 of Family 0x10, AMD processors may have > > support for APERF/MPERF. Add support for identifying it and using > > it within cpufreq. Move the APERF/MPERF functions out of the > > acpi-cpufreq code and into their own file so they can easily be > > shared. > > > > Signed-off-by: Mark Langsdorf <mark.langsdorf(a)amd.com> > > Signed-off-by: Borislav Petkov <borislav.petkov(a)amd.com> > > --- > > arch/x86/kernel/cpu/amd.c | 6 +++ > > arch/x86/kernel/cpu/cpufreq/Makefile | 4 +- > > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 44 +----------------------- > > arch/x86/kernel/cpu/cpufreq/mperf.c | 50 ++++++++++++++++++++++++++++ > > arch/x86/kernel/cpu/cpufreq/mperf.h | 9 +++++ > > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 8 ++++ > > 6 files changed, 77 insertions(+), 44 deletions(-) > > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c > > create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h > > > > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > > index e485825..796f662 100644 > > --- a/arch/x86/kernel/cpu/amd.c > > +++ b/arch/x86/kernel/cpu/amd.c > > @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > > set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); > > } > > > > + if (c->cpuid_level >= 6) { > > + unsigned ecx = cpuid_ecx(6); > > + if (ecx & 0x01) > > + set_cpu_cap(c, X86_FEATURE_APERFMPERF); > > + } > > + > Can you put this into: > arch/x86/kernel/cpu/common.c (or wherever it fits in general x86 cpu init code) > and remove this (arch/x86/kernel/cpu/intel.c): > if (c->cpuid_level > 6) { > unsigned ecx = cpuid_ecx(6); > if (ecx & 0x01) > set_cpu_cap(c, X86_FEATURE_APERFMPERF); > } > > an x86 maintainer might want to double check, but I expect this should work > for all x86 machines? Yes, it should. However, there's the remote, far-fetched possibility that other x86 vendors besides AMD and Intel, might have/plan to have CPUID, base function 6, ECX[1] defined as a completely different feature flag. And then it becomes ugly. Besides, this is, strictly speaking, not x86 generic code but AMD- and Intel-generic (huh, is there something like that? :)) code. So, IMO, this is a judgement call based on the current settings of the duplication and bloating levels of the x86 maintainers' filters :) Let's have some more opinions, please... Thanks. -- Regards/Gruss, Boris. -- Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Valdis.Kletnieks on 25 Mar 2010 16:00
On Thu, 25 Mar 2010 10:43:04 BST, Thomas Renninger said: > > + if (c->cpuid_level >= 6) { > and remove this (arch/x86/kernel/cpu/intel.c): > if (c->cpuid_level > 6) { So is > or >= the correct comparator here? |