vfio/mdev: consolidate all the available_instance sysfs into the core code

Every driver just print a number, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-13-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

2 files changed, 6 insertions, 24 deletions

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 394aab60dbd0..559ca1805592 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -44,20 +44,12 @@ static void vfio_ccw_dma_unmap(struct vfio_device *vdev, u64 iova, u64 length)
 	vfio_ccw_mdev_reset(private);
 }
 
-static ssize_t available_instances_show(struct mdev_type *mtype,
-					struct mdev_type_attribute *attr,
-					char *buf)
+static unsigned int vfio_ccw_get_available(struct mdev_type *mtype)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(mtype->parent->dev);
 
-	return sprintf(buf, "%d\n", atomic_read(&private->avail));
+	return atomic_read(&private->avail);
 }
-static MDEV_TYPE_ATTR_RO(available_instances);
-
-static const struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_available_instances.attr,
-	NULL,
-};
 
 static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
 {
@@ -620,5 +612,5 @@ struct mdev_driver vfio_ccw_mdev_driver = {
 	},
 	.probe = vfio_ccw_mdev_probe,
 	.remove = vfio_ccw_mdev_remove,
-	.types_attrs = mdev_types_attrs,
+	.get_available = vfio_ccw_get_available,
 };
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 5d8dd7e837f3..8606f5d75188 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -790,21 +790,11 @@ static void vfio_ap_mdev_remove(struct mdev_device *mdev)
 	vfio_put_device(&matrix_mdev->vdev);
 }
 
-static ssize_t available_instances_show(struct mdev_type *mtype,
-					struct mdev_type_attribute *attr,
-					char *buf)
+static unsigned int vfio_ap_mdev_get_available(struct mdev_type *mtype)
 {
-	return sprintf(buf, "%d\n",
-		       atomic_read(&matrix_dev->available_instances));
+	return atomic_read(&matrix_dev->available_instances);
 }
 
-static MDEV_TYPE_ATTR_RO(available_instances);
-
-static const struct attribute *vfio_ap_mdev_type_attrs[] = {
-	&mdev_type_attr_available_instances.attr,
-	NULL,
-};
-
 #define MDEV_SHARING_ERR "Userspace may not re-assign queue %02lx.%04lx " \
 			 "already assigned to %s"
 
@@ -1790,7 +1780,7 @@ static struct mdev_driver vfio_ap_matrix_driver = {
 	},
 	.probe = vfio_ap_mdev_probe,
 	.remove = vfio_ap_mdev_remove,
-	.types_attrs = vfio_ap_mdev_type_attrs,
+	.get_available = vfio_ap_mdev_get_available,
 };
 
 int vfio_ap_mdev_register(void)