Add helpers for checking if the given CPU midr falls in a range
of variants/revisions for a given model.

Cc: Will Deacon <will.dea...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Reviewed-by: Dave Martin <dave.mar...@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
 arch/arm64/include/asm/cpufeature.h |  4 ++--
 arch/arm64/include/asm/cputype.h    | 30 ++++++++++++++++++++++++++++++
 arch/arm64/kernel/cpu_errata.c      | 16 +++++-----------
 3 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h 
b/arch/arm64/include/asm/cpufeature.h
index 6a1280493f57..cd245871b578 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>
@@ -306,8 +307,7 @@ 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;
                        const struct arm64_midr_revidr {
                                u32 midr_rv;            /* revision/variant */
                                u32 revidr_mask;
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 350c76a1d15b..bf6cfdab743f 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -117,6 +117,36 @@
 
 #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);
+}
+
 /*
  * 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 9ea14954972c..3c0bb6c4ed02 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -28,9 +28,7 @@ is_affected_midr_range(const struct arm64_cpu_capabilities 
*entry, int scope)
        u32 midr = read_cpuid_id(), revidr;
 
        WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-       if (!MIDR_IS_CPU_MODEL_RANGE(midr, entry->midr_model,
-                                    entry->midr_range_min,
-                                    entry->midr_range_max))
+       if (!is_midr_in_range(midr, &entry->midr_range))
                return false;
 
        midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
@@ -53,7 +51,7 @@ 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
@@ -239,15 +237,11 @@ qcom_enable_link_stack_sanitization(const struct 
arm64_cpu_capabilities *entry)
 
 #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 MIDR_FIXED(rev, revidr_mask) \
        .fixed_revs = (struct arm64_midr_revidr[]){{ (rev), (revidr_mask) }, {}}
@@ -390,7 +384,7 @@ 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

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