[PATCH v3 16/21] xen/drmfront: use xenbus_setup_ring() and xenbus_teardown_ring()

Juergen Gross
2022-05-05T08:18:25Z

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

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/gpu/drm/xen/xen_drm_front_evtchnl.c | 43 ++++++---------------
1 file changed, 11 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
index 4006568b9e32..e52afd792346 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
@@ -123,12 +123,12 @@ static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)
static void evtchnl_free(struct xen_drm_front_info *front_info,
struct xen_drm_front_evtchnl *evtchnl)
{
- unsigned long page = 0;
+ void *page = NULL;

if (evtchnl->type == EVTCHNL_TYPE_REQ)
- page = (unsigned long)evtchnl->u.req.ring.sring;
+ page = evtchnl->u.req.ring.sring;
else if (evtchnl->type == EVTCHNL_TYPE_EVT)
- page = (unsigned long)evtchnl->u.evt.page;
+ page = evtchnl->u.evt.page;
if (!page)
return;

@@ -147,8 +147,7 @@ static void evtchnl_free(struct xen_drm_front_info *front_info,
xenbus_free_evtchn(front_info->xb_dev, evtchnl->port);

/* end access and free the page */
- if (evtchnl->gref != INVALID_GRANT_REF)
- gnttab_end_foreign_access(evtchnl->gref, page);
+ xenbus_teardown_ring(&page, 1, &evtchnl->gref);

memset(evtchnl, 0, sizeof(*evtchnl));
}
@@ -158,8 +157,7 @@ static int evtchnl_alloc(struct xen_drm_front_info *front_info, int index,
enum xen_drm_front_evtchnl_type type)
{
struct xenbus_device *xb_dev = front_info->xb_dev;
- unsigned long page;
- grant_ref_t gref;
+ void *page;
irq_handler_t handler;
int ret;

@@ -168,44 +166,25 @@ static int evtchnl_alloc(struct xen_drm_front_info *front_info, int index,
evtchnl->index = index;
evtchnl->front_info = front_info;
evtchnl->state = EVTCHNL_STATE_DISCONNECTED;
- evtchnl->gref = INVALID_GRANT_REF;

- page = get_zeroed_page(GFP_NOIO | __GFP_HIGH);
- if (!page) {
- ret = -ENOMEM;
+ ret = xenbus_setup_ring(xb_dev, GFP_NOIO | __GFP_HIGH, &page,
+ 1, &evtchnl->gref);
+ if (ret)
goto fail;
- }

if (type == EVTCHNL_TYPE_REQ) {
struct xen_displif_sring *sring;

init_completion(&evtchnl->u.req.completion);
mutex_init(&evtchnl->u.req.req_io_lock);
- sring = (struct xen_displif_sring *)page;
- SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&evtchnl->u.req.ring, sring, XEN_PAGE_SIZE);
-
- ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
- if (ret < 0) {
- evtchnl->u.req.ring.sring = NULL;
- free_page(page);
- goto fail;
- }
+ sring = page;
+ XEN_FRONT_RING_INIT(&evtchnl->u.req.ring, sring, XEN_PAGE_SIZE);

handler = evtchnl_interrupt_ctrl;
} else {
- ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
- virt_to_gfn((void *)page), 0);
- if (ret < 0) {
- free_page(page);
- goto fail;
- }
-
- evtchnl->u.evt.page = (struct xendispl_event_page *)page;
- gref = ret;
+ evtchnl->u.evt.page = page;
handler = evtchnl_interrupt_evt;
}
- evtchnl->gref = gref;

ret = xenbus_alloc_evtchn(xb_dev, &evtchnl->port);
if (ret < 0)
--
2.35.3