Introduce helpers to extract a field of an ID register.
Subsequent patches will use those helpers.
Signed-off-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
.../selftests/kvm/include/aarch64/processor.h | 2 ++
.../testing/selftests/kvm/lib/aarch64/processor.c | 15 +++++++++++++++
2 files changed, 17 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index a8124f9dd68a..a9b4b4e0e592 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -193,4 +193,6 @@ void smccc_hvc(uint32_t function_id, uint64_t arg0, uint64_t arg1,
uint32_t guest_get_vcpuid(void);
+int cpuid_get_sfield(uint64_t val, int field_shift);
+unsigned int cpuid_get_ufield(uint64_t val, int field_shift);
#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 6f5551368944..0b2ad46e7ff5 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -528,3 +528,18 @@ void smccc_hvc(uint32_t function_id, uint64_t arg0, uint64_t arg1,
[arg4] "r"(arg4), [arg5] "r"(arg5), [arg6] "r"(arg6)
: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7");
}
+
+/* Helpers to get a signed/unsigned feature field from ID register value */
+int cpuid_get_sfield(uint64_t val, int field_shift)
+{
+ int width = 4;
+
+ return (int64_t)(val << (64 - width - field_shift)) >> (64 - width);
+}
+
+unsigned int cpuid_get_ufield(uint64_t val, int field_shift)
+{
+ int width = 4;
+
+ return (uint64_t)(val << (64 - width - field_shift)) >> (64 - width);
+}
--
2.37.1.595.g718a3a8f04-goog
