| Message ID | 20201022171209.19494-3-akrowiak@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390/vfio-ap: dynamic configuration support | expand |
On Thu, 22 Oct 2020 13:11:57 -0400 Tony Krowiak <akrowiak@linux.ibm.com> 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@linux.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> > --- > 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. > + put_device(&queue->ap_dev.device); > > return q; > }
On 10/27/20 3:01 AM, Halil Pasic wrote: > On Thu, 22 Oct 2020 13:11:57 -0400 > Tony Krowiak <akrowiak@linux.ibm.com> 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@linux.ibm.com> > Reviewed-by: Halil Pasic <pasic@linux.ibm.com> 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; >> }
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); + + put_device(&queue->ap_dev.device); return q; }
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@linux.ibm.com> --- drivers/s390/crypto/vfio_ap_ops.c | 35 +++++++++++++------------------ 1 file changed, 14 insertions(+), 21 deletions(-)