[PATCH 20/29] arm64: Allow checking of a CPU-local erratum

From: Alex Shi
Date: Tue Feb 27 2018 - 23:00:07 EST


From: Marc Zyngier <marc.zyngier@xxxxxxx>

commit 8f4137588261d7504f4aa022dc9d1a1fd1940e8e upstream.

this_cpu_has_cap() only checks the feature array, and not the errata
one. In order to be able to check for a CPU-local erratum, allow it
to inspect the latter as well.

This is consistent with cpus_have_cap()'s behaviour, which includes
errata already.

Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxx>
---
arch/arm64/kernel/cpufeature.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 3ec6517..4e5dff1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1103,20 +1103,29 @@ static void __init setup_feature_capabilities(void)
* Check if the current CPU has a given feature capability.
* Should be called from non-preemptible context.
*/
-bool this_cpu_has_cap(unsigned int cap)
+static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
+ unsigned int cap)
{
const struct arm64_cpu_capabilities *caps;

if (WARN_ON(preemptible()))
return false;

- for (caps = arm64_features; caps->desc; caps++)
+ for (caps = cap_array; caps->desc; caps++)
if (caps->capability == cap && caps->matches)
return caps->matches(caps, SCOPE_LOCAL_CPU);

return false;
}

+extern const struct arm64_cpu_capabilities arm64_errata[];
+
+bool this_cpu_has_cap(unsigned int cap)
+{
+ return (__this_cpu_has_cap(arm64_features, cap) ||
+ __this_cpu_has_cap(arm64_errata, cap));
+}
+
void __init setup_cpu_features(void)
{
u32 cwg;
--
2.7.4