[PATCH v3 13/21] xen/blkfront: use xenbus_setup_ring() and xenbus_teardown_ring()

Juergen Gross
2022-05-05T08:18:36Z

Simplify blkfront's ring creation and removal via xenbus_setup_ring()
and xenbus_teardown_ring().

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/block/xen-blkfront.c | 37 ++++++++----------------------------
1 file changed, 8 insertions(+), 29 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 7f35e30e626a..bd7b34f29193 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1280,15 +1280,8 @@ static void blkif_free_ring(struct blkfront_ring_info *rinfo)
flush_work(&rinfo->work);

/* Free resources associated with old device channel. */
- for (i = 0; i < info->nr_ring_pages; i++) {
- if (rinfo->ring_ref[i] != INVALID_GRANT_REF) {
- gnttab_end_foreign_access(rinfo->ring_ref[i], 0);
- rinfo->ring_ref[i] = INVALID_GRANT_REF;
- }
- }
- free_pages_exact(rinfo->ring.sring,
- info->nr_ring_pages * XEN_PAGE_SIZE);
- rinfo->ring.sring = NULL;
+ xenbus_teardown_ring((void **)&rinfo->ring.sring, info->nr_ring_pages,
+ rinfo->ring_ref);

if (rinfo->irq)
unbind_from_irqhandler(rinfo->irq, rinfo);
@@ -1679,30 +1672,16 @@ static int setup_blkring(struct xenbus_device *dev,
struct blkfront_ring_info *rinfo)
{
struct blkif_sring *sring;
- int err, i;
+ int err;
struct blkfront_info *info = rinfo->dev_info;
unsigned long ring_size = info->nr_ring_pages * XEN_PAGE_SIZE;
- grant_ref_t gref[XENBUS_MAX_RING_GRANTS];
-
- for (i = 0; i < info->nr_ring_pages; i++)
- rinfo->ring_ref[i] = INVALID_GRANT_REF;

- sring = alloc_pages_exact(ring_size, GFP_NOIO);
- if (!sring) {
- xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
- return -ENOMEM;
- }
- SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&rinfo->ring, sring, ring_size);
-
- err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
- if (err < 0) {
- free_pages_exact(sring, ring_size);
- rinfo->ring.sring = NULL;
+ err = xenbus_setup_ring(dev, GFP_NOIO, (void **)&sring,
+ info->nr_ring_pages, rinfo->ring_ref);
+ if (err)
goto fail;
- }
- for (i = 0; i < info->nr_ring_pages; i++)
- rinfo->ring_ref[i] = gref[i];
+
+ XEN_FRONT_RING_INIT(&rinfo->ring, sring, ring_size);

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