On 2020-04-16 16:45, Tony Krowiak wrote:
On 4/16/20 7:18 AM, Cornelia Huck wrote:
On Tue, 7 Apr 2020 15:20:04 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
Let's implement the callback to indicate when an APQN
is in use by the vfio_ap device driver. The callback is
invoked whenever a change to the apmask or aqmask would
result in one or more queue devices being removed from the driver. The
vfio_ap device driver will indicate a resource is in use
if the APQN of any of the queue devices to be removed are assigned to
any of the matrix mdevs under the driver's control.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_drv.c | 1 +
drivers/s390/crypto/vfio_ap_ops.c | 47 +++++++++++++++++----------
drivers/s390/crypto/vfio_ap_private.h | 2 ++
3 files changed, 33 insertions(+), 17 deletions(-)
@@ -1369,3 +1371,14 @@ void vfio_ap_mdev_remove_queue(struct ap_queue
*queue)
kfree(q);
mutex_unlock(&matrix_dev->lock);
}
+
+bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long
*aqm)
+{
+ bool in_use;
+
+ mutex_lock(&matrix_dev->lock);
+ in_use = vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm) ? true :
false;
Maybe
in_use = !!vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm);
?
To be honest, I find the !! expression very confusing. Every time I see
it, I have
to spend time thinking about what the result of !! is going to be. I think
the statement should be left as-is because it more clearly expresses
the intent.
In other places you use
"
ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
if (ret)
goto share_err;
"
then why use a boolean here?
If you want to return a boolean and you do not want to use !! you can do:
...
ret = vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm);
...
return (ret) ? false : true;
+ mutex_unlock(&matrix_dev->lock);
+
+ return in_use;
+}
--
Pierre Morel
IBM Lab Boeblingen
