On 10/27/20 3:01 AM, Halil Pasic wrote:
On Thu, 22 Oct 2020 13:11:57 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
This patch refactors the vfio_ap device driver to use the AP bus's
ap_get_qdev() function to retrieve the vfio_ap_queue struct containing
information about a queue that is bound to the vfio_ap device driver.
The bus's ap_get_qdev() function retrieves the queue device from a
hashtable keyed by APQN. This is much more efficient than looping over
the list of devices attached to the AP bus by several orders of
magnitude.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Thank you for your review.
---
drivers/s390/crypto/vfio_ap_ops.c | 35 +++++++++++++------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index c471832f0a30..049b97d7444c 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -26,43 +26,36 @@
static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
-static int match_apqn(struct device *dev, const void *data)
-{
- struct vfio_ap_queue *q = dev_get_drvdata(dev);
-
- return (q->apqn == *(int *)(data)) ? 1 : 0;
-}
-
/**
- * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
+ * vfio_ap_get_queue: Retrieve a queue with a specific APQN.
* @matrix_mdev: the associated mediated matrix
* @apqn: The queue APQN
*
- * Retrieve a queue with a specific APQN from the list of the
- * devices of the vfio_ap_drv.
- * Verify that the APID and the APQI are set in the matrix.
+ * Retrieve a queue with a specific APQN from the AP queue devices attached to
+ * the AP bus.
*
- * Returns the pointer to the associated vfio_ap_queue
+ * Returns the pointer to the vfio_ap_queue with the specified APQN, or NULL.
*/
static struct vfio_ap_queue *vfio_ap_get_queue(
struct ap_matrix_mdev *matrix_mdev,
- int apqn)
+ unsigned long apqn)
{
- struct vfio_ap_queue *q;
- struct device *dev;
+ struct ap_queue *queue;
+ struct vfio_ap_queue *q = NULL;
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;
- dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
- &apqn, match_apqn);
- if (!dev)
+ queue = ap_get_qdev(apqn);
+ if (!queue)
return NULL;
- q = dev_get_drvdata(dev);
- q->matrix_mdev = matrix_mdev;
- put_device(dev);
+
+ if (queue->ap_dev.device.driver == &matrix_dev->vfio_ap_drv->driver)
+ q = dev_get_drvdata(&queue->ap_dev.device);
+
Needs to be called with the vfio_ap lock held, right? Otherwise the queue could
get unbound while we are working with it as a vfio_ap_queue... Noting
new, but might we worth documenting.
This is always called with the vfio_ap lock held.
+ put_device(&queue->ap_dev.device);
return q;
}
