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SubjectRe: [PATCH v4 1/2] cpuid: Add a helper in scattered.c to return cpuid leaf info
On Tue, Nov 08, 2016 at 04:52:27PM +0800, He Chen wrote:
> Some sparse cpuid leafs are gathered in a fake leaf to save size of

s/cpuid/CPUID/

> x86_capability array in current code, but sometimes, kernel or other
> modules (e.g. KVM cpuid enumeration) may need actual hardware leaf
> information.
>
> This patch adds a helper get_scattered_cpuid_leaf to rebuild actual

get_scattered_cpuid_leaf()

> cpuid leaf, and it can be called outside by modules.

s/cpuid/CPUID/

> Also, export
> enum cpuid_regs in pt.c and scattered.c to enum cpuid_regs_idx in
> processor.h.

No need for that last sentence - it is obvious when looking at the diff
itself.

> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index 984a7bf..e7f8c62 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -137,6 +137,17 @@ struct cpuinfo_x86 {
> u32 microcode;
> };
>
> +struct cpuid_regs {
> + u32 eax, ebx, ecx, edx;
> +};

Why do you export this? It is used in cpuid.c only.

> +enum cpuid_regs_idx {
> + CPUID_EAX = 0,
> + CPUID_EBX,
> + CPUID_ECX,
> + CPUID_EDX,
> +};
> +
> #define X86_VENDOR_INTEL 0
> #define X86_VENDOR_CYRIX 1
> #define X86_VENDOR_AMD 2
> @@ -178,6 +189,9 @@ extern void identify_secondary_cpu(struct cpuinfo_x86 *);
> extern void print_cpu_info(struct cpuinfo_x86 *);
> void print_cpu_msr(struct cpuinfo_x86 *);
> extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
> +extern u32 get_scattered_cpuid_leaf(unsigned int level,
> + unsigned int sub_leaf,
> + enum cpuid_regs_idx reg);
> extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
> extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
>
> diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
> index 1db8dc4..ef131ea 100644
> --- a/arch/x86/kernel/cpu/scattered.c
> +++ b/arch/x86/kernel/cpu/scattered.c
> @@ -17,11 +17,17 @@ struct cpuid_bit {
> u32 sub_leaf;
> };
>
> -enum cpuid_regs {
> - CR_EAX = 0,
> - CR_ECX,
> - CR_EDX,
> - CR_EBX
> +/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
> +static const struct cpuid_bit cpuid_bits[] = {
> + { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
> + { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
> + { X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 },
> + { X86_FEATURE_AVX512_4VNNIW, CPUID_EDX, 2, 0x00000007, 0 },
> + { X86_FEATURE_AVX512_4FMAPS, CPUID_EDX, 3, 0x00000007, 0 },
> + { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
> + { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
> + { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
> + { 0, 0, 0, 0, 0 }
> };
>
> void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
> @@ -30,18 +36,6 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
> u32 regs[4];
> const struct cpuid_bit *cb;
>
> - static const struct cpuid_bit cpuid_bits[] = {
> - { X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 },
> - { X86_FEATURE_AVX512_4VNNIW, CR_EDX, 2, 0x00000007, 0 },
> - { X86_FEATURE_AVX512_4FMAPS, CR_EDX, 3, 0x00000007, 0 },
> - { X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 },
> - { X86_FEATURE_EPB, CR_ECX, 3, 0x00000006, 0 },
> - { X86_FEATURE_HW_PSTATE, CR_EDX, 7, 0x80000007, 0 },
> - { X86_FEATURE_CPB, CR_EDX, 9, 0x80000007, 0 },
> - { X86_FEATURE_PROC_FEEDBACK, CR_EDX,11, 0x80000007, 0 },
> - { 0, 0, 0, 0, 0 }
> - };
> -
> for (cb = cpuid_bits; cb->feature; cb++) {
>
> /* Verify that the level is valid */

@tip guys: this will conflict with the CAT changes. I've resolved it
this way by keeping the cpuid_bit.level sorted.

@@ -17,11 +17,20 @@ struct cpuid_bit {
u32 sub_leaf;
};

-enum cpuid_regs {
- CR_EAX = 0,
- CR_ECX,
- CR_EDX,
- CR_EBX
+/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
+static const struct cpuid_bit cpuid_bits[] = {
+ { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
+ { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
+ { X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 },
+ { X86_FEATURE_AVX512_4VNNIW, CPUID_EDX, 2, 0x00000007, 0 },
+ { X86_FEATURE_AVX512_4FMAPS, CPUID_EDX, 3, 0x00000007, 0 },
+ { X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 },
+ { X86_FEATURE_CAT_L2, CPUID_EBX, 2, 0x00000010, 0 },
+ { X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
+ { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
+ { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
+ { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
+ { 0, 0, 0, 0, 0 }
};

void init_scattered_cpuid_features(struct cpuinfo_x86 *c)

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

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