void evtchn_set_pending(struct vcpu *v, int port)
{
struct domain *d = v->domain;
shared_info_t *s = d->shared_info;
/*
* The following bit operations must happen in strict order.
* NB. On x86, the atomic bit operations also act as memory barriers.
* There is therefore sufficiently strict ordering for this architecture --
* others may require explicit memory barriers.
*/
if ( test_and_set_bit(port, __shared_info_addr(d, s, evtchn_pending)) )
return;
if ( !test_bit (port, __shared_info_addr(d, s, evtchn_mask)) &&
!test_and_set_bit(port / BITS_PER_GUEST_LONG(d),
vcpu_info_addr(v, evtchn_pending_sel)) )
{
vcpu_mark_events_pending(v);
}
/* Check if some VCPU might be polling for this event. */
if ( unlikely(d->is_polling) )
{
d->is_polling = 0;
smp_mb(); /* check vcpu poll-flags /after/ clearing domain poll-flag */
for_each_vcpu ( d, v )
{
if ( !v->is_polling )
continue;
v->is_polling = 0;
vcpu_unblock(v);
}
}
int evtchn_unmask(unsigned int port)
{
struct domain *d = current->domain;
struct vcpu *v;
ASSERT(spin_is_locked(&d->event_lock));
if ( unlikely(!port_is_valid(d, port)) )
return -EINVAL;
v = d->vcpu[evtchn_from_port(d, port)->notify_vcpu_id];
/*
* These operations must happen in strict order. Based on
* include/xen/event.h:evtchn_set_pending().
*/
if ( test_and_clear_bit(port, &shared_info(d, evtchn_mask)) &&
test_bit (port, &shared_info(d, evtchn_pending)) &&
!test_and_set_bit (port / BITS_PER_EVTCHN_WORD(d),
&vcpu_info(v, evtchn_pending_sel)) )
{
vcpu_mark_events_pending(v);
}
return 0;
}
static void evtchn_2l_unmask(struct domain *d, struct evtchn *evtchn)
{
struct vcpu *v = d->vcpu[evtchn->notify_vcpu_id];
unsigned int port = evtchn->port;
/*
* These operations must happen in strict order. Based on
* evtchn_2l_set_pending() above.
*/
if ( test_and_clear_bit(port, &shared_info(d, evtchn_mask)) &&
test_bit (port, &shared_info(d, evtchn_pending)) &&
!test_and_set_bit (port / BITS_PER_EVTCHN_WORD(d),
&vcpu_info(v, evtchn_pending_sel)) )
{
vcpu_mark_events_pending(v);
}
}
static int evtchn_set_pending(struct vcpu *v, int port)
{
struct domain *d = v->domain;
int vcpuid;
/*
* The following bit operations must happen in strict order.
* NB. On x86, the atomic bit operations also act as memory barriers.
* There is therefore sufficiently strict ordering for this architecture --
* others may require explicit memory barriers.
*/
if ( test_and_set_bit(port, &shared_info(d, evtchn_pending)) )
return 1;
if ( !test_bit (port, &shared_info(d, evtchn_mask)) &&
!test_and_set_bit(port / BITS_PER_EVTCHN_WORD(d),
&vcpu_info(v, evtchn_pending_sel)) )
{
vcpu_mark_events_pending(v);
}
/* Check if some VCPU might be polling for this event. */
if ( likely(bitmap_empty(d->poll_mask, d->max_vcpus)) )
return 0;
/* Wake any interested (or potentially interested) pollers. */
for ( vcpuid = find_first_bit(d->poll_mask, d->max_vcpus);
vcpuid < d->max_vcpus;
vcpuid = find_next_bit(d->poll_mask, d->max_vcpus, vcpuid+1) )
{
v = d->vcpu[vcpuid];
if ( ((v->poll_evtchn <= 0) || (v->poll_evtchn == port)) &&
test_and_clear_bit(vcpuid, d->poll_mask) )
{
v->poll_evtchn = 0;
vcpu_unblock(v);
}
}
return 0;
}
static void evtchn_2l_set_pending(struct vcpu *v, struct evtchn *evtchn)
{
struct domain *d = v->domain;
unsigned int port = evtchn->port;
/*
* The following bit operations must happen in strict order.
* NB. On x86, the atomic bit operations also act as memory barriers.
* There is therefore sufficiently strict ordering for this architecture --
* others may require explicit memory barriers.
*/
if ( test_and_set_bit(port, &shared_info(d, evtchn_pending)) )
return;
if ( !test_bit (port, &shared_info(d, evtchn_mask)) &&
!test_and_set_bit(port / BITS_PER_EVTCHN_WORD(d),
&vcpu_info(v, evtchn_pending_sel)) )
{
vcpu_mark_events_pending(v);
}
evtchn_check_pollers(d, port);
}
