From: Will Deacon <will@xxxxxxxxxx>
Introduce hyp_spin_is_locked() so that functions can easily assert that
a given lock is held (albeit possibly by another CPU!) without having to
drag full lockdep support up to EL2.
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/include/nvhe/spinlock.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/spinlock.h b/arch/arm64/kvm/hyp/include/nvhe/spinlock.h
index 76b537f8d1c6..04f65b655fcf 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/spinlock.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/spinlock.h
@@ -15,6 +15,7 @@
#include <asm/alternative.h>
#include <asm/lse.h>
+#include <asm/rwonce.h>
typedef union hyp_spinlock {
u32 __val;
@@ -89,4 +90,11 @@ static inline void hyp_spin_unlock(hyp_spinlock_t *lock)
: "memory");
}
+static inline bool hyp_spin_is_locked(hyp_spinlock_t *lock)
+{
+ hyp_spinlock_t lockval = READ_ONCE(*lock);
+
+ return lockval.owner != lockval.next;
+}
+
#endif /* __ARM64_KVM_NVHE_SPINLOCK_H__ */
--
2.32.0.605.g8dce9f2422-goog
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