xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: s390: add clear I/O irq operation for FLIC

Browse Source 
Introduce a FLIC operation for clearing I/O interrupts for a subchannel.

Rationale: According to the platform specification, pending I/O
interruption requests have to be revoked in certain situations. For
instance, according to the Principles of Operation (page 17-27), a
subchannel put into the installed parameters initialized state is in the
same state as after an I/O system reset (just parameters possibly changed).
This implies that any I/O interrupts for that subchannel are no longer
pending (as I/O system resets clear I/O interrupts). Therefore, we need an
interface to clear pending I/O interrupts.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Halil Pasic
2016-01-25 19:10:40 +01:00
committed by Cornelia Huck
parent dad7eefbd0
commit 6d28f789bf
3 changed files with 32 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
arch/s390/kvm/interrupt.c
View File

@@ -2034,6 +2034,27 @@ static int modify_io_adapter(struct kvm_device *dev,
return ret;
}
static int clear_io_irq(struct kvm *kvm, struct kvm_device_attr *attr)
{
const u64 isc_mask = 0xffUL << 24; /* all iscs set */
u32 schid;
if (attr->flags)
return -EINVAL;
if (attr->attr != sizeof(schid))
return -EINVAL;
if (copy_from_user(&schid, (void __user *) attr->addr, sizeof(schid)))
return -EFAULT;
kfree(kvm_s390_get_io_int(kvm, isc_mask, schid));
/*
* If userspace is conforming to the architecture, we can have at most
* one pending I/O interrupt per subchannel, so this is effectively a
* clear all.
*/
return 0;
}
static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
int r = 0;
@@ -2067,6 +2088,9 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
case KVM_DEV_FLIC_ADAPTER_MODIFY:
r = modify_io_adapter(dev, attr);
break;
case KVM_DEV_FLIC_CLEAR_IO_IRQ:
r = clear_io_irq(dev->kvm, attr);
break;
default:
r = -EINVAL;
}
@@ -2085,6 +2109,7 @@ static int flic_has_attr(struct kvm_device *dev,
case KVM_DEV_FLIC_APF_DISABLE_WAIT:
case KVM_DEV_FLIC_ADAPTER_REGISTER:
case KVM_DEV_FLIC_ADAPTER_MODIFY:
case KVM_DEV_FLIC_CLEAR_IO_IRQ:
return 0;
}
return -ENXIO;