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Subject[PATCH v4 17/22] arm64: Add helpers for checking CPU MIDR against a range
Date
Add helpers for checking if the given CPU midr falls in a range
of variants/revisions for a given model.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@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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