[PATCH v3 19/21] xen/usbfront: use xenbus_setup_ring() and xenbus_teardown_ring()

Juergen Gross
2022-05-05T08:19:27Z

Simplify xen-hcd's ring creation and removal via xenbus_setup_ring()
and xenbus_teardown_ring().

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/host/xen-hcd.c | 61 ++++++++++----------------------------
1 file changed, 15 insertions(+), 46 deletions(-)

diff --git a/drivers/usb/host/xen-hcd.c b/drivers/usb/host/xen-hcd.c
index 9cbc7c2dab02..de1b09158318 100644
--- a/drivers/usb/host/xen-hcd.c
+++ b/drivers/usb/host/xen-hcd.c
@@ -1098,19 +1098,10 @@ static void xenhcd_destroy_rings(struct xenhcd_info *info)
unbind_from_irqhandler(info->irq, info);
info->irq = 0;

- if (info->urb_ring_ref != INVALID_GRANT_REF) {
- gnttab_end_foreign_access(info->urb_ring_ref,
- (unsigned long)info->urb_ring.sring);
- info->urb_ring_ref = INVALID_GRANT_REF;
- }
- info->urb_ring.sring = NULL;
-
- if (info->conn_ring_ref != INVALID_GRANT_REF) {
- gnttab_end_foreign_access(info->conn_ring_ref,
- (unsigned long)info->conn_ring.sring);
- info->conn_ring_ref = INVALID_GRANT_REF;
- }
- info->conn_ring.sring = NULL;
+ xenbus_teardown_ring((void **)&info->urb_ring.sring, 1,
+ &info->urb_ring_ref);
+ xenbus_teardown_ring((void **)&info->conn_ring.sring, 1,
+ &info->conn_ring_ref);
}

static int xenhcd_setup_rings(struct xenbus_device *dev,
@@ -1118,46 +1109,24 @@ static int xenhcd_setup_rings(struct xenbus_device *dev,
{
struct xenusb_urb_sring *urb_sring;
struct xenusb_conn_sring *conn_sring;
- grant_ref_t gref;
int err;

- info->urb_ring_ref = INVALID_GRANT_REF;
info->conn_ring_ref = INVALID_GRANT_REF;
-
- urb_sring = (struct xenusb_urb_sring *)get_zeroed_page(
- GFP_NOIO | __GFP_HIGH);
- if (!urb_sring) {
- xenbus_dev_fatal(dev, -ENOMEM, "allocating urb ring");
- return -ENOMEM;
- }
- SHARED_RING_INIT(urb_sring);
- FRONT_RING_INIT(&info->urb_ring, urb_sring, PAGE_SIZE);
-
- err = xenbus_grant_ring(dev, urb_sring, 1, &gref);
- if (err < 0) {
- free_page((unsigned long)urb_sring);
- info->urb_ring.sring = NULL;
- goto fail;
- }
- info->urb_ring_ref = gref;
-
- conn_sring = (struct xenusb_conn_sring *)get_zeroed_page(
- GFP_NOIO | __GFP_HIGH);
- if (!conn_sring) {
- xenbus_dev_fatal(dev, -ENOMEM, "allocating conn ring");
- err = -ENOMEM;
- goto fail;
+ err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH,
+ (void **)&urb_sring, 1, &info->urb_ring_ref);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "allocating urb ring");
+ return err;
}
- SHARED_RING_INIT(conn_sring);
- FRONT_RING_INIT(&info->conn_ring, conn_sring, PAGE_SIZE);
+ XEN_FRONT_RING_INIT(&info->urb_ring, urb_sring, PAGE_SIZE);

- err = xenbus_grant_ring(dev, conn_sring, 1, &gref);
- if (err < 0) {
- free_page((unsigned long)conn_sring);
- info->conn_ring.sring = NULL;
+ err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH,
+ (void **)&conn_sring, 1, &info->conn_ring_ref);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "allocating conn ring");
goto fail;
}
- info->conn_ring_ref = gref;
+ XEN_FRONT_RING_INIT(&info->conn_ring, conn_sring, PAGE_SIZE);

err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err) {
--
2.35.3