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authorWill Deacon <[email protected]>2021-08-09 16:24:28 +0100
committerMarc Zyngier <[email protected]>2021-08-11 11:39:35 +0100
commitd21292f13f1f0721d60e8122e2db46bea8cf6950 (patch)
treec3e61017f835146991d86b43e78ecd3988da0f7e
parent63db506e07622c344a3c748a1c06293d48780f83 (diff)
KVM: arm64: Add hyp_spin_is_locked() for basic locking assertions at EL2
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 <[email protected]> Signed-off-by: Quentin Perret <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Link: https://lore.kernel.org/r/[email protected]
-rw-r--r--arch/arm64/kvm/hyp/include/nvhe/spinlock.h8
1 files changed, 8 insertions, 0 deletions
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__ */