/**
* xb_init_comms - Set up interrupt handler off store event channel.
*/
int xb_init_comms(void)
{
struct xenstore_domain_interface *intf = xen_store_interface;
if (intf->req_prod != intf->req_cons)
printk(KERN_ERR "XENBUS request ring is not quiescent "
"(%08x:%08x)!\n", intf->req_cons, intf->req_prod);
if (intf->rsp_prod != intf->rsp_cons) {
printk(KERN_WARNING "XENBUS response ring is not quiescent "
"(%08x:%08x): fixing up\n",
intf->rsp_cons, intf->rsp_prod);
/* breaks kdump */
if (!reset_devices)
intf->rsp_cons = intf->rsp_prod;
}
if (xenbus_irq) {
/* Already have an irq; assume we're resuming */
rebind_evtchn_irq(xen_store_evtchn, xenbus_irq);
} else {
int err;
err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
0, "xenbus", &xb_waitq);
if (err <= 0) {
printk(KERN_ERR "XENBUS request irq failed %i\n", err);
return err;
}
xenbus_irq = err;
}
return 0;
}
static int evtchn_bind_to_user(struct per_user_data *u, int port)
{
int rc = 0;
/*
* Ports are never reused, so every caller should pass in a
* unique port.
*
* (Locking not necessary because we haven't registered the
* interrupt handler yet, and our caller has already
* serialized bind operations.)
*/
BUG_ON(get_port_user(port) != NULL);
set_port_user(port, u);
set_port_enabled(port, true); /* start enabled */
rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED,
u->name, (void *)(unsigned long)port);
if (rc >= 0)
rc = evtchn_make_refcounted(port);
else {
/* bind failed, should close the port now */
struct evtchn_close close;
close.port = port;
if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
BUG();
set_port_user(port, NULL);
}
return rc;
}
int gnt_init(void)
{
int mfn;
int err;
struct as_sring *sring;
struct evtchn_alloc_unbound alloc_unbound;
printk(KERN_INFO "gnt_init\n");
page = __get_free_pages(GFP_KERNEL, 0);
if (page == 0) {
printk(KERN_DEBUG "\nxen:DomU:could not get free page");
return 0;
}
sring = (struct as_sring *)page;
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&(info.ring), sring, PAGE_SIZE);
mfn = virt_to_mfn(page);
printk(KERN_INFO "grant foreign access\n");
info.gref = gnttab_grant_foreign_access(DOM0_ID, mfn, 0);
if (info.gref < 0) {
printk(KERN_DEBUG "\nxen:could not grant foreign access");
free_page((unsigned long)page);
info.ring.sring = NULL;
return 0;
}
printk(KERN_DEBUG "\n gref = %d", info.gref);
alloc_unbound.dom = DOMID_SELF;
alloc_unbound.remote_dom = DOM0_ID;
err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &alloc_unbound);
if (err) {
printk(KERN_DEBUG "\nalloc unbound port failure");
return err;
}
err = bind_evtchn_to_irqhandler(alloc_unbound.port, as_int, 0, "xen-eg", &info);
if (err < 0) {
printk(KERN_DEBUG "\nbind evtchn to irqhandler failure");
return err;
}
info.irq = err;
info.port = alloc_unbound.port;
printk(KERN_DEBUG " interrupt = %d, local_port = %d", info.irq, info.port);
printk("...\n...");
create_procfs_entry();
return 0;
}
static int xenkbd_connect_backend(struct xenbus_device *dev,
struct xenkbd_info *info)
{
int ret, evtchn;
struct xenbus_transaction xbt;
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
return ret;
ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
0, dev->devicetype, info);
if (ret < 0) {
xenbus_free_evtchn(dev, evtchn);
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
return ret;
}
info->irq = ret;
again:
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
return ret;
}
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
virt_to_mfn(info->page));
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
evtchn);
if (ret)
goto error_xenbus;
ret = xenbus_transaction_end(xbt, 0);
if (ret) {
if (ret == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, ret, "completing transaction");
return ret;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
return ret;
}
static int setup_ixpring(struct xenbus_device *dev,
struct ixpfront_info *info)
{
struct ixp_sring *sring;
int err;
info->ring_ref = GRANT_INVALID_REF;
sring = (struct ixp_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if (!sring) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
return -ENOMEM;
}
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
if (err < 0) {
free_page((unsigned long)sring);
info->ring.sring = NULL;
goto fail;
}
info->ring_ref = err;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
goto fail;
err = bind_evtchn_to_irqhandler(info->evtchn,
ixp_interrupt,
IRQF_SAMPLE_RANDOM, "ixp", info);
if (err <= 0) {
xenbus_dev_fatal(dev, err,
"bind_evtchn_to_irqhandler failed");
goto fail;
}
info->irq = err;
return 0;
fail:
ixp_free(info, 0);
return err;
}
/* Set up interrupt handler off store event channel. */
int xb_init_comms(void)
{
int err;
if (xenbus_irq)
unbind_from_irqhandler(xenbus_irq, &xb_waitq);
err = bind_evtchn_to_irqhandler(
xen_store_evtchn, wake_waiting,
0, "xenbus", &xb_waitq);
if (err <= 0) {
printk(KERN_ERR "XENBUS request irq failed %i\n", err);
return err;
}
xenbus_irq = err;
return 0;
}
static int evtchn_bind_to_user(struct per_user_data *u, int port)
{
int rc = 0;
/*
* Ports are never reused, so every caller should pass in a
* unique port.
*
* (Locking not necessary because we haven't registered the
* interrupt handler yet, and our caller has already
* serialized bind operations.)
*/
BUG_ON(port_user[port] != NULL);
port_user[port] = u;
rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED,
u->name, (void *)(unsigned long)port);
if (rc >= 0)
rc = 0;
return rc;
}
int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
{
blkif_sring_t *sring;
int err;
struct evtchn_bind_interdomain bind_interdomain;
if ((blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL)
return -ENOMEM;
err = map_frontend_page(blkif, shared_page);
if (err) {
free_vm_area(blkif->blk_ring_area);
return err;
}
bind_interdomain.remote_dom = blkif->domid;
bind_interdomain.remote_port = evtchn;
err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
&bind_interdomain);
if (err) {
unmap_frontend_page(blkif);
free_vm_area(blkif->blk_ring_area);
return err;
}
blkif->evtchn = bind_interdomain.local_port;
sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
blkif->irq = bind_evtchn_to_irqhandler(
blkif->evtchn, blkif_be_int, 0, "blkif-backend", blkif);
blkif->status = CONNECTED;
return 0;
}
/* caller must clean up in case of errors */
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);
if (rv < 0)
return rv;
priv->ring_ref = gref;
rv = xenbus_alloc_evtchn(dev, &priv->evtchn);
if (rv)
return rv;
rv = bind_evtchn_to_irqhandler(priv->evtchn, tpmif_interrupt, 0,
"tpmif", priv);
if (rv <= 0) {
xenbus_dev_fatal(dev, rv, "allocating TPM irq");
return rv;
}
priv->irq = rv;
again:
rv = xenbus_transaction_start(&xbt);
if (rv) {
xenbus_dev_fatal(dev, rv, "starting transaction");
return rv;
}
rv = xenbus_printf(xbt, dev->nodename,
"ring-ref", "%u", priv->ring_ref);
if (rv) {
message = "writing ring-ref";
goto abort_transaction;
}
rv = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
priv->evtchn);
if (rv) {
message = "writing event-channel";
goto abort_transaction;
}
rv = xenbus_printf(xbt, dev->nodename, "feature-protocol-v2", "1");
if (rv) {
message = "writing feature-protocol-v2";
goto abort_transaction;
}
rv = xenbus_transaction_end(xbt, 0);
if (rv == -EAGAIN)
goto again;
if (rv) {
xenbus_dev_fatal(dev, rv, "completing transaction");
return rv;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
abort_transaction:
xenbus_transaction_end(xbt, 1);
if (message)
xenbus_dev_error(dev, rv, "%s", message);
return rv;
}
static int xenkbd_connect_backend(struct xenbus_device *dev,
struct xenkbd_info *info)
{
int ret, evtchn;
struct xenbus_transaction xbt;
ret = gnttab_grant_foreign_access(dev->otherend_id,
virt_to_gfn(info->page), 0);
if (ret < 0)
return ret;
info->gref = ret;
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
goto error_grant;
ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
0, dev->devicetype, info);
if (ret < 0) {
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
goto error_evtchan;
}
info->irq = ret;
again:
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
goto error_irqh;
}
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
virt_to_gfn(info->page));
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
evtchn);
if (ret)
goto error_xenbus;
ret = xenbus_transaction_end(xbt, 0);
if (ret) {
if (ret == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, ret, "completing transaction");
goto error_irqh;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
error_irqh:
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
error_evtchan:
xenbus_free_evtchn(dev, evtchn);
error_grant:
gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1;
return ret;
}
int netif_map(netif_t *netif, unsigned long tx_ring_ref,
unsigned long rx_ring_ref, unsigned int evtchn)
{
int err = -ENOMEM;
netif_tx_sring_t *txs;
netif_rx_sring_t *rxs;
struct evtchn_bind_interdomain bind_interdomain;
/* Already connected through? */
if (netif->irq)
return 0;
netif->tx_comms_area = alloc_vm_area(PAGE_SIZE);
if (netif->tx_comms_area == NULL)
return -ENOMEM;
netif->rx_comms_area = alloc_vm_area(PAGE_SIZE);
if (netif->rx_comms_area == NULL)
goto err_rx;
err = map_frontend_pages(netif, tx_ring_ref, rx_ring_ref);
if (err)
goto err_map;
bind_interdomain.remote_dom = netif->domid;
bind_interdomain.remote_port = evtchn;
err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
&bind_interdomain);
if (err)
goto err_hypervisor;
netif->evtchn = bind_interdomain.local_port;
netif->irq = bind_evtchn_to_irqhandler(
netif->evtchn, netif_be_int, 0, netif->dev->name, netif);
disable_irq(netif->irq);
txs = (netif_tx_sring_t *)netif->tx_comms_area->addr;
BACK_RING_INIT(&netif->tx, txs, PAGE_SIZE);
rxs = (netif_rx_sring_t *)
((char *)netif->rx_comms_area->addr);
BACK_RING_INIT(&netif->rx, rxs, PAGE_SIZE);
netif->rx_req_cons_peek = 0;
netif_get(netif);
wmb(); /* Other CPUs see new state before interface is started. */
rtnl_lock();
netif->status = CONNECTED;
wmb();
if (netif_running(netif->dev))
__netif_up(netif);
rtnl_unlock();
return 0;
err_hypervisor:
unmap_frontend_pages(netif);
err_map:
free_vm_area(netif->rx_comms_area);
err_rx:
free_vm_area(netif->tx_comms_area);
return err;
}
/**
* Connect the OpenXT input device to the corresponding backend.
*
* @param dev The device to be connected.
* @param info The information structure that corresponds to the given device.
*
* @return int Zero on success, or an error code on failure.
*/
static int oxtkbd_connect_backend(struct xenbus_device *dev,
struct openxt_kbd_info *info)
{
int ret, evtchn;
struct xenbus_transaction xbt;
//To communicate with the backend, we'll share a single page of memory
//We'll start this process by granting out our "shared page".
ret = gnttab_grant_foreign_access(dev->otherend_id, virt_to_mfn(info->page), 0);
if (ret < 0)
return ret;
info->gref = ret;
//Next, we'll need to create an event channel we can use to signal that data
//has changed in our shared page.
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
goto error_grant;
//Bind our input handler to our event channel-- ensuring we're recieve any
//"new data" notifications.
ret = bind_evtchn_to_irqhandler(evtchn, input_handler, 0, dev->devicetype, info);
if (ret < 0) {
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
goto error_evtchan;
}
info->irq = ret;
again:
//Now that we've set up our shared assets, we'll need to communicate them
//to the backend. First, we'll start a xenbus transaction, so we can dump
//all of our data into the XenStore simultaneously.
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
goto error_irqh;
}
//Provide a direct reference to the page. This allows backends that want
//to use foreign mappings (i.e. legacy backends) to map in the shared page
//without touching grants.
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu", virt_to_mfn(info->page));
if (ret)
goto error_xenbus;
//And provide our grant reference. This is the preferred way of getting the
//shared page.
ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
if (ret)
goto error_xenbus;
//Provide the number for our event channel, so the backend can signal
//new informatino to us.
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", evtchn);
if (ret)
goto error_xenbus;
//Attempt to apply all of our changes at once.
ret = xenbus_transaction_end(xbt, 0);
//If our transaction failed...
if (ret) {
//... it may have been because the XenStore was busy. If this is the case,
//repeat out transaction until we succeed, or hit an error.
if (ret == -EAGAIN)
goto again;
//Otherwise, we couldn't connect. Bail out!
xenbus_dev_fatal(dev, ret, "completing transaction");
goto error_irqh;
}
//Finally, switch our state to "intialized", hopefully cueing the backend
//to connect.
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
error_irqh:
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
error_evtchan:
xenbus_free_evtchn(dev, evtchn);
error_grant:
gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1;
return ret;
}
