genode/base-nova/include/nova/util.h
Alexander Boettcher fe19103546 nova: create sm for signalling via pager
The 'pause' call on base-nova assumes that a thread can solely block in its
associated semaphore. Main reason is that so core can unblock a thread in order
that the recall exception gets delivered and the register state can be
obtained.

Unfortunately the signal session implementation creates a semaphore, which is
unknown by the pager code. Instead create the semaphore via the pager of the
thread, so that the pager can unblock the signal thread when a pause is issued.

Issue #478
2013-10-16 09:26:09 +02:00

68 lines
1.7 KiB
C++

/*
* \brief Helper code used by core as base framework
* \author Alexander Boettcher
* \date 2012-08-08
*/
/*
* Copyright (C) 2012-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _NOVA__INCLUDE__UTIL_H_
#define _NOVA__INCLUDE__UTIL_H_
#include <base/printf.h>
#include <base/thread.h>
__attribute__((always_inline))
inline void nova_die(const char * text = 0)
{
/*
* If thread is de-constructed the sessions are already gone.
* Be careful when enabling printf here.
*/
while (1)
asm volatile ("ud2a" : : "a"(text));
}
inline void request_event_portal(Genode::Native_capability const &cap,
Genode::addr_t sel, Genode::addr_t event,
unsigned short log2_count = 0)
{
using namespace Nova;
Utcb *utcb = (Utcb *)Genode::Thread_base::myself()->utcb();
/* save original receive window */
Crd orig_crd = utcb->crd_rcv;
/* request event-handler portal */
utcb->crd_rcv = Obj_crd(sel, log2_count);
utcb->msg[0] = event;
utcb->msg[1] = log2_count;
utcb->set_msg_word(2);
uint8_t res = call(cap.local_name());
/* restore original receive window */
utcb->crd_rcv = orig_crd;
if (res)
PERR("request of event (%lu) capability selector failed", event);
}
inline void request_native_ec_cap(Genode::Native_capability const &cap,
Genode::addr_t sel) {
request_event_portal(cap, sel , ~0UL, 1); }
inline void request_signal_sm_cap(Genode::Native_capability const &cap,
Genode::addr_t sel) {
request_event_portal(cap, sel, ~0UL - 1, 0); }
#endif /* _NOVA__INCLUDE__UTIL_H_ */