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/*
* Event channel port operations.
*
* Copyright (c) 2003-2006, K A Fraser.
*
* This source code is licensed under the GNU General Public License,
* Version 2 or later. See the file COPYING for more details.
*/
#include <xen/config.h>
#include <xen/init.h>
#include <xen/lib.h>
#include <xen/errno.h>
#include <xen/sched.h>
#include <xen/event.h>
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);
}
static void evtchn_2l_clear_pending(struct domain *d, struct evtchn *evtchn)
{
clear_bit(evtchn->port, &shared_info(d, evtchn_pending));
}
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 bool_t evtchn_2l_is_pending(struct domain *d,
const struct evtchn *evtchn)
{
return test_bit(evtchn->port, &shared_info(d, evtchn_pending));
}
static bool_t evtchn_2l_is_masked(struct domain *d,
const struct evtchn *evtchn)
{
return test_bit(evtchn->port, &shared_info(d, evtchn_mask));
}
static const struct evtchn_port_ops evtchn_port_ops_2l =
{
.set_pending = evtchn_2l_set_pending,
.clear_pending = evtchn_2l_clear_pending,
.unmask = evtchn_2l_unmask,
.is_pending = evtchn_2l_is_pending,
.is_masked = evtchn_2l_is_masked,
};
void evtchn_2l_init(struct domain *d)
{
d->evtchn_port_ops = &evtchn_port_ops_2l;
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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