Messages in this thread Patch in this message | | | Date | Thu, 29 Jul 2021 14:27:58 +0100 | Subject | [PATCH v3 01/21] KVM: arm64: Add hyp_spin_is_locked() for basic locking assertions at EL2 | From | Quentin Perret <> |
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From: Will Deacon <will@kernel.org>
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@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> --- 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__ */ -- 2.32.0.432.gabb21c7263-goog
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