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SubjectRe: [RFC][git-pull -tip] x86: cpu_debug and cpufeature patches

* Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:

> On Sun, 2009-05-03 at 11:09 +0200, Ingo Molnar wrote:
> > * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> >
> > > We can use cpu_has tests for unknown processors but 'cpu model' is
> > > accurate and cover all range.
> > >
> > > cpu_has does not cover following registers:
> > > 1. platform
> > > 2. poweron
> > > 3. control
> > > 4. bios
> > > 5. freq
> > > 6. cache
> > > 7. misc
> > > 8. base
> > > 9. ver
> > > 10. conf
> >
> > Firstly these should be added to cpufeatures.h.
> >
> > Then add cpu_has_xxx() accessors need to be added for them and
> > during CPU init they have to be properly set, via two methods:
> >
> > - via CPUID (where this is possible+specified in docs)
> > - or via "later than CPU version X" checks
> >
> > Your cpu-model table is equivalent to an explicitly enumerated CPU
> > version check, but this breaks every time a new CPU comes out.
> >
> > "Later than" or CPUID based feature bits are a lot more future-proof
> > - we only have to add support for new _features_ (and quirks,
> > occasionally), and dont have to maintain that full table of specific
> > models to specific features mapping tables.
> >
>
> I add some cpufeatures for review, I am still adding rest of them.
>
> The following changes since commit c861b6f8ea9b39699f4a35bbf7dc06eb937a34de:
> Ingo Molnar (1):
> Merge branch 'irq/urgent'
>
> are available in the git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/jaswinder/linux-2.6-tip.git master
>
> Jaswinder Singh Rajput (6):
> x86: cpu_debug.c avoid storing cpu_descriptors locally
> x86: cpu_debug update Kconfig entry
> x86: cpu_debug.c remove unwanted header files
> x86: Add cpufeature for Processor Name
> x86: Add cpufeatures for Advanced Power Management
> x86: Add cpufeature for Microcode update
>
> arch/x86/Kconfig | 11 ++++++++-
> arch/x86/include/asm/cpufeature.h | 21 ++++++++++++++----
> arch/x86/include/asm/processor.h | 1 -
> arch/x86/kernel/cpu/Makefile | 2 +-
> arch/x86/kernel/cpu/amd.c | 9 --------
> arch/x86/kernel/cpu/common.c | 16 +++++++++++++-
> arch/x86/kernel/cpu/cpu_debug.c | 42 +++++++++++++++++-------------------
> arch/x86/kernel/cpu/intel.c | 14 ------------
> arch/x86/kernel/cpu/powerflags.c | 20 -----------------
> arch/x86/kernel/cpu/proc.c | 14 ------------
> arch/x86/kernel/microcode_amd.c | 3 ++
> arch/x86/kernel/microcode_intel.c | 3 ++
> 12 files changed, 68 insertions(+), 88 deletions(-)
> delete mode 100644 arch/x86/kernel/cpu/powerflags.c
>
> Complete diff:
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 4395f4f..213cbca 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -951,7 +951,16 @@ config X86_CPU_DEBUG
> tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
> ---help---
> If you select this option, this will provide various x86 CPUs
> - information through debugfs.
> + information through debugfs. Any user can read these file but writing
> + needs root privilege.
> +
> + Note: 1. If you compile cpu_debug as a module, it will _not_ be loaded
> + automatically (like usual drivers). You will need to load it manually
> + (or add it to list of modules loaded during boot).
> +
> + 2. You need debugfs, if you want to mount debugfs automatically
> + append this line in /etc/fstab:
> + debugfs /sys/kernel/debug debugfs defaults 0 0
>
> choice
> prompt "High Memory Support"
> diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
> index bb83b1c..64aebdd 100644
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -6,7 +6,7 @@
>
> #include <asm/required-features.h>
>
> -#define NCAPINTS 9 /* N 32-bit words worth of info */
> +#define NCAPINTS 10 /* N 32-bit words worth of info */
>
> /*
> * Note: If the comment begins with a quoted string, that string is used
> @@ -76,7 +76,6 @@
> #define X86_FEATURE_K7 (3*32+ 5) /* "" Athlon */
> #define X86_FEATURE_P3 (3*32+ 6) /* "" P3 */
> #define X86_FEATURE_P4 (3*32+ 7) /* "" P4 */
> -#define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */
> #define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */
> #define X86_FEATURE_FXSAVE_LEAK (3*32+10) /* "" FXSAVE leaks FOP/FIP/FOP */
> #define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */
> @@ -153,8 +152,10 @@
> * Auxiliary flags: Linux defined - For features scattered in various
> * CPUID levels like 0x6, 0xA etc
> */
> -#define X86_FEATURE_IDA (7*32+ 0) /* Intel Dynamic Acceleration */
> -#define X86_FEATURE_ARAT (7*32+ 1) /* Always Running APIC Timer */
> +#define X86_FEATURE_IDA (7*32+ 0) /* Intel Dynamic Acceleration */
> +#define X86_FEATURE_ARAT (7*32+ 1) /* Always Running APIC Timer */
> +#define X86_FEATURE_PNAME (7*32+ 2) /* Processor Name */
> +#define X86_FEATURE_MICROCODE (7*32+ 3) /* Microcode update */
>
> /* Virtualization flags: Linux defined */
> #define X86_FEATURE_TPR_SHADOW (8*32+ 0) /* Intel TPR Shadow */
> @@ -163,12 +164,22 @@
> #define X86_FEATURE_EPT (8*32+ 3) /* Intel Extended Page Table */
> #define X86_FEATURE_VPID (8*32+ 4) /* Intel Virtual Processor ID */
>
> +/* Advanced Power Management (Function 8000_0007h), edx */
> +#define X86_FEATURE_TS (9*32+ 0) /* Temperatue sensor */
> +#define X86_FEATURE_FID (9*32+ 1) /* Frequency ID control */
> +#define X86_FEATURE_VID (9*32+ 2) /* Voltage ID control */
> +#define X86_FEATURE_TTP (9*32+ 3) /* Thermal trip */
> +#define X86_FEATURE_HTC (9*32+ 4) /* Hardware thermal control */
> +#define X86_FEATURE_STC (9*32+ 5) /* Software thermal control */
> +#define X86_FEATURE_100MHZSTEPS (9*32+ 6) /* 100 MHz multiplier control */
> +#define X86_FEATURE_HWPSTATE (9*32+ 7) /* Hardware P-State control */
> +#define X86_FEATURE_CONSTANT_TSC (9*32+ 8) /* Constant rate TSC ticks */
> +

Yes, this general approach looks pretty good! Note how it reduces
the line count in fact.

I havent looked deeply yet, but noticed that above you changed
X86_FEATURE_CONSTANT_TSC - why was that done?

Ingo


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