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SubjectRe: [PATCH v2 14/20] arm64: Add helpers for checking CPU MIDR against a range
On Wed, Jan 31, 2018 at 06:28:01PM +0000, Suzuki K Poulose wrote:
> Add helpers for checking if the given CPU midr falls in a range
> of variants/revisions for a given model.
>
> Cc: Dave Martin <dave.martin@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Reviewed-by: Dave Martin <Dave.Martin@arm.com>

> ---
> arch/arm64/include/asm/cpufeature.h | 7 ++-----
> arch/arm64/include/asm/cputype.h | 38 +++++++++++++++++++++++++++++++++++++
> arch/arm64/kernel/cpu_errata.c | 16 +++++-----------
> 3 files changed, 45 insertions(+), 16 deletions(-)
>
> diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
> index 42292a0b93a4..0cfe42c3225c 100644
> --- a/arch/arm64/include/asm/cpufeature.h
> +++ b/arch/arm64/include/asm/cpufeature.h
> @@ -10,6 +10,7 @@
> #define __ASM_CPUFEATURE_H
>
> #include <asm/cpucaps.h>
> +#include <asm/cputype.h>
> #include <asm/fpsimd.h>
> #include <asm/hwcap.h>
> #include <asm/sigcontext.h>
> @@ -279,11 +280,7 @@ struct arm64_cpu_capabilities {
> */
> void (*cpu_enable)(const struct arm64_cpu_capabilities *cap);
> union {
> - struct { /* To be used for erratum handling only */
> - u32 midr_model;
> - u32 midr_range_min, midr_range_max;
> - };
> -
> + struct midr_range midr_range; /* To be used for erratum handling only */
> struct { /* Feature register checking */
> u32 sys_reg;
> u8 field_pos;
> diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
> index 2f8d39ed9c2e..26bc5b302060 100644
> --- a/arch/arm64/include/asm/cputype.h
> +++ b/arch/arm64/include/asm/cputype.h
> @@ -115,6 +115,44 @@
>
> #define read_cpuid(reg) read_sysreg_s(SYS_ ## reg)
>
> +/*
> + * Represent a range of MIDR values for a given CPU model and a
> + * range of variant/revision values.
> + *
> + * @model - CPU model as defined by MIDR_CPU_MODEL
> + * @rv_min - Minimum value for the revision/variant as defined by
> + * MIDR_CPU_VAR_REV
> + * @rv_max - Maximum value for the variant/revision for the range.
> + */
> +struct midr_range {
> + u32 model;
> + u32 rv_min;
> + u32 rv_max;
> +};
> +
> +#define MIDR_RANGE(m, v_min, r_min, v_max, r_max) \
> + { \
> + .model = m, \
> + .rv_min = MIDR_CPU_VAR_REV(v_min, r_min), \
> + .rv_max = MIDR_CPU_VAR_REV(v_max, r_max), \
> + }
> +
> +#define MIDR_ALL_VERSIONS(m) MIDR_RANGE(m, 0, 0, 0xf, 0xf)
> +
> +static inline bool is_midr_in_range(u32 midr, struct midr_range const *range)
> +{
> + return MIDR_IS_CPU_MODEL_RANGE(midr, range->model,
> + range->rv_min, range->rv_max);
> +}
> +
> +static inline bool is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
> +{
> + while (ranges->model)
> + if (is_midr_in_range(midr, ranges++))
> + return true;
> + return false;
> +}
> +
> /*
> * The CPU ID never changes at run time, so we might as well tell the
> * compiler that it's constant. Use this function to read the CPU ID
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index 4351d48b0b0f..bc3f7dce42ba 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -25,9 +25,7 @@ static bool __maybe_unused
> is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
> {
> WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
> - return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
> - entry->midr_range_min,
> - entry->midr_range_max);
> + return is_midr_in_range(read_cpuid_id(), &entry->midr_range);
> }
>
> static bool __maybe_unused
> @@ -41,7 +39,7 @@ is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
> model &= MIDR_IMPLEMENTOR_MASK | (0xf00 << MIDR_PARTNUM_SHIFT) |
> MIDR_ARCHITECTURE_MASK;
>
> - return model == entry->midr_model;
> + return model == entry->midr_range.model;
> }
>
> static bool
> @@ -176,15 +174,11 @@ static void qcom_enable_link_stack_sanitization(
>
> #define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \
> .matches = is_affected_midr_range, \
> - .midr_model = model, \
> - .midr_range_min = MIDR_CPU_VAR_REV(v_min, r_min), \
> - .midr_range_max = MIDR_CPU_VAR_REV(v_max, r_max)
> + .midr_range = MIDR_RANGE(model, v_min, r_min, v_max, r_max)
>
> #define CAP_MIDR_ALL_VERSIONS(model) \
> .matches = is_affected_midr_range, \
> - .midr_model = model, \
> - .midr_range_min = MIDR_CPU_VAR_REV(0, 0), \
> - .midr_range_max = (MIDR_VARIANT_MASK | MIDR_REVISION_MASK)
> + .midr_range = MIDR_ALL_VERSIONS(model)
>
> #define ERRATA_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \
> .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
> @@ -315,7 +309,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
> .desc = "Qualcomm Technologies Kryo erratum 1003",
> .capability = ARM64_WORKAROUND_QCOM_FALKOR_E1003,
> .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
> - .midr_model = MIDR_QCOM_KRYO,
> + .midr_range.model = MIDR_QCOM_KRYO,
> .matches = is_kryo_midr,
> },
> #endif
> --
> 2.14.3
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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