[PATCH 00/18] xen: simplify frontend side ring setup
Many Xen PV frontends share similar code for setting up a ring page (allocating and granting access for the backend) and for tearing it down.
Create new service functions doing all needed steps in one go.
This requires all frontends to use a common value for an invalid grant reference in order to make the functions idempotent.
Juergen Gross (18): xen/blkfront: switch blkfront to use INVALID_GRANT_REF xen/netfront: switch netfront to use INVALID_GRANT_REF xen/scsifront: remove unused GRANT_INVALID_REF definition xen/usb: switch xen-hcd to use INVALID_GRANT_REF xen/drm: switch xen_drm_front to use INVALID_GRANT_REF xen/sound: switch xen_snd_front to use INVALID_GRANT_REF xen/dmabuf: switch gntdev-dmabuf to use INVALID_GRANT_REF xen/shbuf: switch xen-front-pgdir-shbuf to use INVALID_GRANT_REF xen/xenbus: add xenbus_setup_ring() service function xen/blkfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/netfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/tpmfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/drmfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/pcifront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/scsifront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/usbfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/sndfront: use xenbus_setup_ring() and xenbus_teardown_ring() xen/xenbus: eliminate xenbus_grant_ring()
drivers/block/xen-blkfront.c | 54 ++++---------- drivers/char/tpm/xen-tpmfront.c | 18 +---- drivers/gpu/drm/xen/xen_drm_front.h | 9 --- drivers/gpu/drm/xen/xen_drm_front_evtchnl.c | 40 +++------- drivers/net/xen-netfront.c | 77 ++++++-------------- drivers/pci/xen-pcifront.c | 19 +---- drivers/scsi/xen-scsifront.c | 30 ++------ drivers/usb/host/xen-hcd.c | 59 ++++----------- drivers/xen/gntdev-dmabuf.c | 13 +--- drivers/xen/xen-front-pgdir-shbuf.c | 17 +---- drivers/xen/xenbus/xenbus_client.c | 81 ++++++++++++++++----- include/xen/xenbus.h | 4 +- sound/xen/xen_snd_front_evtchnl.c | 41 +++-------- sound/xen/xen_snd_front_evtchnl.h | 9 --- 14 files changed, 156 insertions(+), 315 deletions(-)
Instead of using a private macro for an invalid grant reference use the common one.
Signed-off-by: Juergen Gross jgross@suse.com --- sound/xen/xen_snd_front_evtchnl.c | 4 ++-- sound/xen/xen_snd_front_evtchnl.h | 9 --------- 2 files changed, 2 insertions(+), 11 deletions(-)
diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c index ecbc294fc59a..3e21369c8216 100644 --- a/sound/xen/xen_snd_front_evtchnl.c +++ b/sound/xen/xen_snd_front_evtchnl.c @@ -167,7 +167,7 @@ static void evtchnl_free(struct xen_snd_front_info *front_info, xenbus_free_evtchn(front_info->xb_dev, channel->port);
/* End access and free the page. */ - if (channel->gref != GRANT_INVALID_REF) + if (channel->gref != INVALID_GRANT_REF) gnttab_end_foreign_access(channel->gref, page); else free_page(page); @@ -207,7 +207,7 @@ static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, channel->index = index; channel->front_info = front_info; channel->state = EVTCHNL_STATE_DISCONNECTED; - channel->gref = GRANT_INVALID_REF; + channel->gref = INVALID_GRANT_REF; page = get_zeroed_page(GFP_KERNEL); if (!page) { ret = -ENOMEM; diff --git a/sound/xen/xen_snd_front_evtchnl.h b/sound/xen/xen_snd_front_evtchnl.h index cbe51fd1ec15..3675fba70564 100644 --- a/sound/xen/xen_snd_front_evtchnl.h +++ b/sound/xen/xen_snd_front_evtchnl.h @@ -15,15 +15,6 @@
struct xen_snd_front_info;
-#ifndef GRANT_INVALID_REF -/* - * FIXME: usage of grant reference 0 as invalid grant reference: - * grant reference 0 is valid, but never exposed to a PV driver, - * because of the fact it is already in use/reserved by the PV console. - */ -#define GRANT_INVALID_REF 0 -#endif - /* Timeout in ms to wait for backend to respond. */ #define VSND_WAIT_BACK_MS 3000
Simplify sndfront's ring creation and removal via xenbus_setup_ring() and xenbus_teardown_ring().
Signed-off-by: Juergen Gross jgross@suse.com --- sound/xen/xen_snd_front_evtchnl.c | 41 +++++++------------------------ 1 file changed, 9 insertions(+), 32 deletions(-)
diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c index 3e21369c8216..32d42fd3f7ac 100644 --- a/sound/xen/xen_snd_front_evtchnl.c +++ b/sound/xen/xen_snd_front_evtchnl.c @@ -143,12 +143,12 @@ void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel) static void evtchnl_free(struct xen_snd_front_info *front_info, struct xen_snd_front_evtchnl *channel) { - unsigned long page = 0; + void *page = NULL;
if (channel->type == EVTCHNL_TYPE_REQ) - page = (unsigned long)channel->u.req.ring.sring; + page = channel->u.req.ring.sring; else if (channel->type == EVTCHNL_TYPE_EVT) - page = (unsigned long)channel->u.evt.page; + page = channel->u.evt.page;
if (!page) return; @@ -167,10 +167,7 @@ static void evtchnl_free(struct xen_snd_front_info *front_info, xenbus_free_evtchn(front_info->xb_dev, channel->port);
/* End access and free the page. */ - if (channel->gref != INVALID_GRANT_REF) - gnttab_end_foreign_access(channel->gref, page); - else - free_page(page); + xenbus_teardown_ring(&page, 1, &channel->gref);
memset(channel, 0, sizeof(*channel)); } @@ -196,8 +193,7 @@ static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, enum xen_snd_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; char *handler_name = NULL; int ret; @@ -207,12 +203,9 @@ static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, channel->index = index; channel->front_info = front_info; channel->state = EVTCHNL_STATE_DISCONNECTED; - channel->gref = INVALID_GRANT_REF; - page = get_zeroed_page(GFP_KERNEL); - if (!page) { - ret = -ENOMEM; + ret = xenbus_setup_ring(xb_dev, GFP_KERNEL, &page, 1, &channel->gref); + if (ret) goto fail; - }
handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME, type == EVTCHNL_TYPE_REQ ? @@ -226,33 +219,19 @@ static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, mutex_init(&channel->ring_io_lock);
if (type == EVTCHNL_TYPE_REQ) { - struct xen_sndif_sring *sring = (struct xen_sndif_sring *)page; + struct xen_sndif_sring *sring = page;
init_completion(&channel->u.req.completion); mutex_init(&channel->u.req.req_io_lock); SHARED_RING_INIT(sring); FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE);
- ret = xenbus_grant_ring(xb_dev, sring, 1, &gref); - if (ret < 0) { - channel->u.req.ring.sring = NULL; - goto fail; - } - handler = evtchnl_interrupt_req; } else { - ret = gnttab_grant_foreign_access(xb_dev->otherend_id, - virt_to_gfn((void *)page), 0); - if (ret < 0) - goto fail; - - channel->u.evt.page = (struct xensnd_event_page *)page; - gref = ret; + channel->u.evt.page = page; handler = evtchnl_interrupt_evt; }
- channel->gref = gref; - ret = xenbus_alloc_evtchn(xb_dev, &channel->port); if (ret < 0) goto fail; @@ -279,8 +258,6 @@ static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, return 0;
fail: - if (page) - free_page(page); kfree(handler_name); dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret); return ret;
participants (1)
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Juergen Gross