Introduce a couple of helpers to extract a field of ID registers.
Signed-off-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
.../selftests/kvm/include/aarch64/processor.h | 5 ++++
.../selftests/kvm/lib/aarch64/processor.c | 27 +++++++++++++++++++
2 files changed, 32 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 8f9f46979a00..e12411fec822 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -185,4 +185,9 @@ static inline void local_irq_disable(void)
asm volatile("msr daifset, #3" : : : "memory");
}
+int extract_signed_field(uint64_t val, int field, int width);
+unsigned int extract_unsigned_field(uint64_t val, int field, int width);
+int cpuid_extract_ftr(uint64_t val, int field, bool sign);
+int cpuid_extract_sftr(uint64_t val, int field);
+unsigned int cpuid_extract_uftr(uint64_t val, int field);
#endif /* SELFTEST_KVM_PROCESSOR_H */
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 9343d82519b4..c55f7dfc8567 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -500,3 +500,30 @@ void __attribute__((constructor)) init_guest_modes(void)
{
guest_modes_append_default();
}
+
+/* Helpers to get a feature field from ID register value */
+int extract_signed_field(uint64_t val, int field, int width)
+{
+ return (int64_t)(val << (64 - width - field)) >> (64 - width);
+}
+
+unsigned int extract_unsigned_field(uint64_t val, int field, int width)
+{
+ return (uint64_t)(val << (64 - width - field)) >> (64 - width);
+}
+
+int cpuid_extract_ftr(uint64_t val, int field, bool sign)
+{
+ return (sign) ? extract_signed_field(val, field, 4) :
+ extract_unsigned_field(val, field, 4);
+}
+
+int cpuid_extract_sftr(uint64_t val, int field)
+{
+ return cpuid_extract_ftr(val, field, true);
+}
+
+unsigned int cpuid_extract_uftr(uint64_t val, int field)
+{
+ return cpuid_extract_ftr(val, field, false);
+}
--
2.36.0.rc0.470.gd361397f0d-goog
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