On 01/25/2018 02:28 PM, Christian Borntraeger wrote:
> From: Michael Mueller <mimu@xxxxxxxxxxxxxxxxxx>
>
> The function returns a pending I/O interrupt with the highest
> priority defined by its ISC.
>
> Together with AIV activation, pending adapter interrupts are
> managed by the GISA IPM. Thus kvm_s390_get_io_int() needs to
> inspect the IPM as well when the interrupt with the highest
> priority has to be identified.
>
> In case classic and adapter interrupts with the same ISC are
> pending, the classic interrupt will be returned first.
>
> Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/interrupt.c | 71 +++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 65 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index 0edf97a..5c48930 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -1471,12 +1471,8 @@ static struct kvm_s390_interrupt_info *get_io_int(struct kvm *kvm,
> return NULL;
> }
>
> -/*
> - * Dequeue and return an I/O interrupt matching any of the interruption
> - * subclasses as designated by the isc mask in cr6 and the schid (if != 0).
> - */
> -struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,
> - u64 isc_mask, u32 schid)
> +static struct kvm_s390_interrupt_info *get_top_io_int(struct kvm *kvm,
> + u64 isc_mask, u32 schid)
> {
> struct kvm_s390_interrupt_info *inti = NULL;
> int isc;
> @@ -1488,6 +1484,69 @@ struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,
> return inti;
> }
>
> +static int get_top_gisa_isc(struct kvm *kvm, u64 isc_mask, u32 schid)
> +{
> + unsigned long active_mask;
> + int isc;
> +
> + if (schid)
> + goto out;
> + if (!kvm->arch.gisa)
> + goto out;
> +
> + active_mask = (isc_mask & kvm_s390_gisa_get_ipm(kvm->arch.gisa) << 24) << 32;
> + while (active_mask) {
> + isc = __flogr(active_mask);
Sebastian Ott noticed that newer binutils will complain about that when
compiling for z990 or older.
I will use the equivalent
- isc = __flogr(active_mask);
+ isc = __fls(active_mask) ^ (BITS_PER_LONG - 1);
