diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 040745b23224..9faaa8f96fc3 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -249,6 +249,25 @@ static inline int gisa_set_iam(struct kvm_s390_gisa *gisa, u8 iam) return 0; } +/** + * gisa_clear_ipm - clear the GISA interruption pending mask + * + * @gisa: gisa to operate on + * + * Clear the IPM atomically with the next alert address and the IAM + * of the GISA unconditionally. All three fields are located in the + * first long word of the GISA. + */ +static inline void gisa_clear_ipm(struct kvm_s390_gisa *gisa) +{ + u64 word, _word; + + do { + word = READ_ONCE(gisa->u64.word[0]); + _word = word & ~(0xffUL << 24); + } while (cmpxchg(&gisa->u64.word[0], word, _word) != word); +} + static inline void gisa_set_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc) { set_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa); @@ -2926,8 +2945,7 @@ void kvm_s390_gisa_clear(struct kvm *kvm) if (!gi->origin) return; - memset(gi->origin, 0, sizeof(struct kvm_s390_gisa)); - gi->origin->next_alert = (u32)(u64)gi->origin; + gisa_clear_ipm(gi->origin); VM_EVENT(kvm, 3, "gisa 0x%pK cleared", gi->origin); } @@ -2940,7 +2958,8 @@ void kvm_s390_gisa_init(struct kvm *kvm) gi->origin = &kvm->arch.sie_page2->gisa; gi->alert.mask = 0; spin_lock_init(&gi->alert.ref_lock); - kvm_s390_gisa_clear(kvm); + memset(gi->origin, 0, sizeof(struct kvm_s390_gisa)); + gi->origin->next_alert = (u32)(u64)gi->origin; VM_EVENT(kvm, 3, "gisa 0x%pK initialized", gi->origin); }