diff options
| -rw-r--r-- | drivers/xen/pvcalls-front.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index a8d38c283014..aae23d046967 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -20,6 +20,51 @@ #include <xen/xenbus.h> #include <xen/interface/io/pvcalls.h> +#define PVCALLS_INVALID_ID UINT_MAX +#define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER +#define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) + +struct pvcalls_bedata { + struct xen_pvcalls_front_ring ring; + grant_ref_t ref; + int irq; + + struct list_head socket_mappings; + spinlock_t socket_lock; + + wait_queue_head_t inflight_req; + struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING]; +}; +/* Only one front/back connection supported. */ +static struct xenbus_device *pvcalls_front_dev; +static atomic_t pvcalls_refcount; + +/* first increment refcount, then proceed */ +#define pvcalls_enter() { \ + atomic_inc(&pvcalls_refcount); \ +} + +/* first complete other operations, then decrement refcount */ +#define pvcalls_exit() { \ + atomic_dec(&pvcalls_refcount); \ +} + +struct sock_mapping { + bool active_socket; + struct list_head list; + struct socket *sock; +}; + +static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) +{ + return IRQ_HANDLED; +} + +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, + struct sock_mapping *map) +{ +} + static const struct xenbus_device_id pvcalls_front_ids[] = { { "pvcalls" }, { "" } @@ -27,6 +72,32 @@ static const struct xenbus_device_id pvcalls_front_ids[] = { static int pvcalls_front_remove(struct xenbus_device *dev) { + struct pvcalls_bedata *bedata; + struct sock_mapping *map = NULL, *n; + + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + dev_set_drvdata(&dev->dev, NULL); + pvcalls_front_dev = NULL; + if (bedata->irq >= 0) + unbind_from_irqhandler(bedata->irq, dev); + + smp_mb(); + while (atomic_read(&pvcalls_refcount) > 0) + cpu_relax(); + list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { + if (map->active_socket) { + /* No need to lock, refcount is 0 */ + pvcalls_front_free_map(bedata, map); + } else { + list_del(&map->list); + kfree(map); + } + } + if (bedata->ref >= 0) + gnttab_end_foreign_access(bedata->ref, 0, 0); + kfree(bedata->ring.sring); + kfree(bedata); + xenbus_switch_state(dev, XenbusStateClosed); return 0; } |