[PATCH v3 17/21] xen/pcifront: use xenbus_setup_ring() and xenbus_teardown_ring()

Juergen Gross
2022-05-05T08:18:55Z

Simplify pcifront's shared page creation and removal via
xenbus_setup_ring() and xenbus_teardown_ring().

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/pci/xen-pcifront.c | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 3edc1565a27c..689271c4245c 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -709,9 +709,8 @@ static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
if (pdev == NULL)
goto out;

- pdev->sh_info =
- (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
- if (pdev->sh_info == NULL) {
+ if (xenbus_setup_ring(xdev, GFP_KERNEL, (void **)&pdev->sh_info, 1,
+ &pdev->gnt_ref)) {
kfree(pdev);
pdev = NULL;
goto out;
@@ -729,7 +728,6 @@ static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
spin_lock_init(&pdev->sh_info_lock);

pdev->evtchn = INVALID_EVTCHN;
- pdev->gnt_ref = INVALID_GRANT_REF;
pdev->irq = -1;

INIT_WORK(&pdev->op_work, pcifront_do_aer);
@@ -754,11 +752,7 @@ static void free_pdev(struct pcifront_device *pdev)
if (pdev->evtchn != INVALID_EVTCHN)
xenbus_free_evtchn(pdev->xdev, pdev->evtchn);

- if (pdev->gnt_ref != INVALID_GRANT_REF)
- gnttab_end_foreign_access(pdev->gnt_ref,
- (unsigned long)pdev->sh_info);
- else
- free_page((unsigned long)pdev->sh_info);
+ xenbus_teardown_ring((void **)&pdev->sh_info, 1, &pdev->gnt_ref);

dev_set_drvdata(&pdev->xdev->dev, NULL);

@@ -769,13 +763,6 @@ static int pcifront_publish_info(struct pcifront_device *pdev)
{
int err = 0;
struct xenbus_transaction trans;
- grant_ref_t gref;
-
- err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
- if (err < 0)
- goto out;
-
- pdev->gnt_ref = gref;

err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
if (err)
--
2.35.3