[PATCH 13/18] arm64: Drop BBML2_NOABORT requirement for HVO

[James Houghton]

With PMD updates being done with the Access Flag trick, BBML2_NOABORT is
no longer needed.

Dropping this requirement vastly widens the pool of systems this
optimization is valid for.

Intentionally leave HVO as opt-in, as enabling HVO still introduces the
following regression: if all boot CPUs support HW AF, then any
late-onlined CPUs that do not will not be onlined.

Signed-off-by: James Houghton <jthoughton at google.com>
---
 arch/arm64/kernel/cpufeature.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 3b9224b99a5f..c13433316e80 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2175,11 +2175,10 @@ static bool has_bbml2_noabort(const struct arm64_cpu_capabilities *caps, int sco
 static bool hvo_compatible(const struct arm64_cpu_capabilities *caps, int scope)
 {
 	/*
-	 * We need BBML2 to support Block -> Table transitions without taking
-	 * faults, and we need HW AF support to support changing the OA without
-	 * taking faults.
+	 * We need HW AF support to support changing vmemmap mapping level and
+	 * OA without taking faults.
 	 */
-	return cpu_supports_bbml2_noabort() && supports_hw_af(scope);
+	return supports_hw_af(scope);
 }
 
 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
-- 
2.55.0.795.g602f6c329a-goog