On 4/8/20 12:27 PM, Cornelia Huck wrote:
On Wed, 8 Apr 2020 11:38:07 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
On 4/8/20 6:48 AM, Cornelia Huck wrote:
On Tue, 7 Apr 2020 15:20:01 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
Rather than looping over potentially 65535 objects, let's store the
structures for caching information about queue devices bound to the
vfio_ap device driver in a hash table keyed by APQN.
This also looks like a nice code simplification.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_drv.c | 28 +++------
drivers/s390/crypto/vfio_ap_ops.c | 90 ++++++++++++++-------------
drivers/s390/crypto/vfio_ap_private.h | 10 ++-
3 files changed, 60 insertions(+), 68 deletions(-)
(...)
- */
-static struct vfio_ap_queue *vfio_ap_get_queue(
- struct ap_matrix_mdev *matrix_mdev,
- int apqn)
+struct vfio_ap_queue *vfio_ap_get_queue(unsigned long apqn)
{
struct vfio_ap_queue *q;
- struct device *dev;
-
- if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
- return NULL;
- if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
- return NULL;
These were just optimizations and therefore can be dropped now?
The purpose of this function has changed from its previous incarnation.
This function was originally called from the handle_pqap() function and
served two purposes: It retrieved the struct vfio_ap_queue as driver data
and linked the matrix_mdev to the vfio_ap_queue. The linking of the
matrix_mdev and the vfio_ap_queue are now done when queue devices
are probed and when adapters and domains are assigned; so now, the
handle_pqap() function calls this function to retrieve both the
vfio_ap_queue as well as the matrix_mdev to which it is linked.
Consequently,
the above code is no longer needed.
Thanks for the explanation, that makes sense.
-
- dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
- &apqn, match_apqn);
- if (!dev)
- return NULL;
- q = dev_get_drvdata(dev);
- q->matrix_mdev = matrix_mdev;
- put_device(dev);
- return q;
+ hash_for_each_possible(matrix_dev->qtable, q, qnode, apqn) {
+ if (q && (apqn == q->apqn))
+ return q;
+ }
Do we need any serialization here? Previously, the driver core made
sure we could get a reference only if the device was still registered;
not sure if we need any further guarantees now.
The vfio_ap_queue structs are created when the queue device is
probed and removed when the queue device is removed.
Ok, so anything further is not needed.
+
+ return NULL;
}
/**
(...)
Looks good to me, then. With vfio_ap_get_queue made static and the
kerneldoc restored/updated:
Already done, thanks for the review.
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
