[PATCH v3 15/21] xen/tpmfront: use xenbus_setup_ring() and xenbus_teardown_ring()

Juergen Gross
2022-05-05T08:19:35Z

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

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/char/tpm/xen-tpmfront.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
index 69df04ae2401..379291826261 100644
--- a/drivers/char/tpm/xen-tpmfront.c
+++ b/drivers/char/tpm/xen-tpmfront.c
@@ -253,20 +253,12 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv)
struct xenbus_transaction xbt;
const char *message = NULL;
int rv;
- grant_ref_t gref;

- priv->shr = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
- if (!priv->shr) {
- xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
- return -ENOMEM;
- }
-
- rv = xenbus_grant_ring(dev, priv->shr, 1, &gref);
+ rv = xenbus_setup_ring(dev, GFP_KERNEL, (void **)&priv->shr, 1,
+ &priv->ring_ref);
if (rv < 0)
return rv;

- priv->ring_ref = gref;
-
rv = xenbus_alloc_evtchn(dev, &priv->evtchn);
if (rv)
return rv;
@@ -331,11 +323,7 @@ static void ring_free(struct tpm_private *priv)
if (!priv)
return;

- if (priv->ring_ref)
- gnttab_end_foreign_access(priv->ring_ref,
- (unsigned long)priv->shr);
- else
- free_page((unsigned long)priv->shr);
+ xenbus_teardown_ring((void **)&priv->shr, 1, &priv->ring_ref);

if (priv->irq)
unbind_from_irqhandler(priv->irq, priv);
--
2.35.3