[PATCH v3 18/21] xen/scsifront: use xenbus_setup_ring() and xenbus_teardown_ring()

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

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

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/scsi/xen-scsifront.c | 28 +++++++---------------------
1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index 4c55e479fc36..51afc66e839d 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -798,27 +798,15 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
{
struct xenbus_device *dev = info->dev;
struct vscsiif_sring *sring;
- grant_ref_t gref;
- int err = -ENOMEM;
+ int err;

/***** Frontend to Backend ring start *****/
- sring = (struct vscsiif_sring *)__get_free_page(GFP_KERNEL);
- if (!sring) {
- xenbus_dev_fatal(dev, err,
- "fail to allocate shared ring (Front to Back)");
+ err = xenbus_setup_ring(dev, GFP_KERNEL, (void **)&sring, 1,
+ &info->ring_ref);
+ if (err)
return err;
- }
- SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);

- err = xenbus_grant_ring(dev, sring, 1, &gref);
- if (err < 0) {
- free_page((unsigned long)sring);
- xenbus_dev_fatal(dev, err,
- "fail to grant shared ring (Front to Back)");
- return err;
- }
- info->ring_ref = gref;
+ XEN_FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);

err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err) {
@@ -847,8 +835,7 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
free_irq:
unbind_from_irqhandler(info->irq, info);
free_gnttab:
- gnttab_end_foreign_access(info->ring_ref,
- (unsigned long)info->ring.sring);
+ xenbus_teardown_ring((void **)&sring, 1, &info->ring_ref);

return err;
}
@@ -856,8 +843,7 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
static void scsifront_free_ring(struct vscsifrnt_info *info)
{
unbind_from_irqhandler(info->irq, info);
- gnttab_end_foreign_access(info->ring_ref,
- (unsigned long)info->ring.sring);
+ xenbus_teardown_ring((void **)&info->ring.sring, 1, &info->ring_ref);
}

static int scsifront_init_ring(struct vscsifrnt_info *info)
--
2.35.3