arm64: spectre: Consolidate spectre-v3a detection

The spectre-v3a mitigation is split between cpu_errata.c and spectre.c,
with the former handling detection of the problem and the latter handling
enabling of the workaround.

Move the detection logic alongside the enabling logic, like we do for the
other spectre mitigations.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20201113113847.21619-10-will@kernel.org

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index cf9f8b885aea..d89be9882998 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -277,6 +277,18 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
  * an indirect trampoline for the hyp vectors so that guests can't read
  * VBAR_EL2 to defeat randomisation of the hypervisor VA layout.
  */
+bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	static const struct midr_range spectre_v3a_unsafe_list[] = {
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
+		{},
+	};
+
+	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+	return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list);
+}
+
 void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
 {
 	struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);