Commit d21292f1 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

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: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarQuentin Perret <qperret@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-2-qperret@google.com
parent 63db506e

arch/arm64/kvm/hyp/include/nvhe/spinlock.h

+8 −0
Original line number Diff line number Diff line
@@ -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__ */