int
xb_read(void *data, unsigned len)
{
volatile struct xenstore_domain_interface *intf =
xs_domain_interface(xb_addr);
XENSTORE_RING_IDX cons, prod;
extern int do_polled_io;
while (len != 0) {
unsigned int avail;
const char *src;
mutex_enter(&xb_wait_lock);
while (intf->rsp_cons == intf->rsp_prod) {
if (interrupts_unleashed && !do_polled_io) {
if (cv_wait_sig(&xb_wait_cv,
&xb_wait_lock) == 0) {
mutex_exit(&xb_wait_lock);
return (EINTR);
}
} else { /* polled mode needed for early probes */
(void) HYPERVISOR_yield();
}
}
mutex_exit(&xb_wait_lock);
/* Read indexes, then verify. */
cons = intf->rsp_cons;
prod = intf->rsp_prod;
membar_enter();
if (!check_indexes(cons, prod))
return (EIO);
src = get_input_chunk(cons, prod, (char *)intf->rsp, &avail);
if (avail == 0)
continue;
if (avail > len)
avail = len;
/* We must read header before we read data. */
membar_consumer();
(void) memcpy(data, src, avail);
data = (void *)((uintptr_t)data + avail);
len -= avail;
/* Other side must not see free space until we've copied out */
membar_enter();
intf->rsp_cons += avail;
/* Implies mb(): they will see new header. */
ec_notify_via_evtchn(xen_info->store_evtchn);
}
return (0);
}
int
xb_read(void *data, unsigned len)
{
struct xenstore_domain_interface *intf = xenstore_domain_interface();
XENSTORE_RING_IDX cons, prod;
int s = spltty();
while (len != 0) {
unsigned int avail;
const char *src;
while (intf->rsp_cons == intf->rsp_prod)
tsleep(&xenstore_interface, PRIBIO, "rdst", 0);
/* Read indexes, then verify. */
cons = intf->rsp_cons;
prod = intf->rsp_prod;
xen_rmb();
if (!check_indexes(cons, prod)) {
XENPRINTF(("xb_read EIO\n"));
splx(s);
return EIO;
}
src = get_input_chunk(cons, prod, intf->rsp, &avail);
if (avail == 0)
continue;
if (avail > len)
avail = len;
/* We must read header before we read data. */
xen_rmb();
memcpy(data, src, avail);
data = (char *)data + avail;
len -= avail;
/* Other side must not see free space until we've copied out */
xen_rmb();
intf->rsp_cons += avail;
xen_rmb();
XENPRINTF(("Finished read of %i bytes (%i to go)\n",
avail, len));
hypervisor_notify_via_evtchn(xen_start_info.store_evtchn);
}
splx(s);
return 0;
}
int xb_read(void *data, unsigned len)
{
struct xenstore_domain_interface *intf = xen_store_interface;
XENSTORE_RING_IDX cons, prod;
int rc;
while (len != 0) {
unsigned int avail;
const char *src;
rc = wait_event_interruptible(
xb_waitq,
intf->rsp_cons != intf->rsp_prod);
if (rc < 0)
return rc;
/* Read indexes, then verify. */
cons = intf->rsp_cons;
prod = intf->rsp_prod;
mb();
if (!check_indexes(cons, prod)) {
intf->rsp_cons = intf->rsp_prod = 0;
return -EIO;
}
src = get_input_chunk(cons, prod, intf->rsp, &avail);
if (avail == 0)
continue;
if (avail > len)
avail = len;
/* We must read header before we read data. */
rmb();
memcpy(data, src, avail);
data += avail;
len -= avail;
/* Other side must not see free space until we've copied out */
mb();
intf->rsp_cons += avail;
pr_debug("Finished read of %i bytes (%i to go)\n", avail, len);
/* Implies mb(): they will see new header. */
notify_remote_via_evtchn(xen_store_evtchn);
}
return 0;
}
int xb_read(void *data, unsigned len)
{
struct xenstore_domain_interface *intf = xen_store_interface;
XENSTORE_RING_IDX cons, prod;
int rc;
while (len != 0) {
unsigned int avail;
const char *src;
rc = xb_wait_for_data_to_read();
if (rc < 0)
return rc;
/* Read indexes, then verify. */
cons = intf->rsp_cons;
prod = intf->rsp_prod;
if (!check_indexes(cons, prod)) {
intf->rsp_cons = intf->rsp_prod = 0;
return -EIO;
}
src = get_input_chunk(cons, prod, intf->rsp, &avail);
if (avail == 0)
continue;
if (avail > len)
avail = len;
/* Must read data /after/ reading the producer index. */
virt_rmb();
memcpy(data, src, avail);
data += avail;
len -= avail;
/* Other side must not see free space until we've copied out */
virt_mb();
intf->rsp_cons += avail;
pr_debug("Finished read of %i bytes (%i to go)\n", avail, len);
/* Implies mb(): other side will see the updated consumer. */
notify_remote_via_evtchn(xen_store_evtchn);
}
return 0;
}
