genode/base-nova/src/base/pager/pager.cc
2012-08-09 11:09:41 +02:00

192 lines
5.3 KiB
C++

/*
* \brief Pager framework
* \author Norman Feske
* \author Sebastian Sumpf
* \date 2010-01-25
*/
/*
* Copyright (C) 2010-2012 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.
*/
/* Genode includes */
#include <base/cap_sel_alloc.h>
#include <base/pager.h>
#include <base/sleep.h>
/* NOVA includes */
#include <nova/syscalls.h>
using namespace Genode;
using namespace Nova;
enum { PF_HANDLER_STACK_SIZE = sizeof(addr_t) * 1024 };
void Pager_object::_page_fault_handler()
{
Ipc_pager ipc_pager;
ipc_pager.wait_for_fault();
/* serialize page-fault handling */
Thread_base *myself = Thread_base::myself();
if (!myself) {
PWRN("unexpected page-fault for non-existing pager object,"
" going to sleep forever");
sleep_forever();
}
Pager_object *obj = static_cast<Pager_object *>(myself);
int ret = obj->pager(ipc_pager);
if (ret) {
PWRN("unresolvable page-fault at address 0x%lx, ip=0x%lx",
ipc_pager.fault_addr(), ipc_pager.fault_ip());
/* revoke paging capability, let thread die in kernel */
Nova::revoke(Obj_crd(obj->exc_pt_sel() + PT_SEL_PAGE_FAULT, 0),
true);
Utcb *utcb = (Utcb *)Thread_base::myself()->utcb();
utcb->set_msg_word(0);
}
ipc_pager.reply_and_wait_for_fault();
}
void Pager_object::_startup_handler()
{
Pager_object *obj = static_cast<Pager_object *>(Thread_base::myself());
Utcb *utcb = (Utcb *)Thread_base::myself()->utcb();
// printf("start new pager object with EIP=0x%p, ESP=0x%p\n",
// (void *)obj->_initial_eip, (void *)obj->_initial_esp);
utcb->eip = obj->_initial_eip;
utcb->esp = obj->_initial_esp;
utcb->mtd = Mtd::EIP | Mtd::ESP;
utcb->set_msg_word(0);
reply(Thread_base::myself()->stack_top());
}
void Pager_object::_invoke_handler()
{
Utcb *utcb = (Utcb *)Thread_base::myself()->utcb();
Pager_object *obj = static_cast<Pager_object *>(Thread_base::myself());
/* send single portal as reply */
addr_t event = utcb->msg[0];
utcb->mtd = 0;
utcb->set_msg_word(0);
if (event == PT_SEL_STARTUP || event == PT_SEL_PAGE_FAULT) {
bool res = utcb->append_item(Obj_crd(obj->exc_pt_sel() + event,
0), 0);
/* one item ever fits on the UTCB */
(void)res;
}
reply(Thread_base::myself()->stack_top());
}
void Pager_object::wake_up() { PDBG("not yet implemented"); }
Pager_object::Pager_object(unsigned long badge)
: Thread_base("pager", PF_HANDLER_STACK_SIZE), _badge(badge)
{
_pt_cleanup = cap_selector_allocator()->alloc();
/* create portal for page-fault handler */
addr_t pd_sel = __core_pd_sel;
uint8_t res = create_pt(exc_pt_sel() + PT_SEL_PAGE_FAULT, pd_sel,
_tid.ec_sel, Mtd(Mtd::QUAL | Mtd::EIP),
(mword_t)_page_fault_handler);
if (res) {
PERR("could not create page-fault portal, error = %u\n",
res);
class Create_page_fault_pt_failed { };
throw Create_page_fault_pt_failed();
}
/* create portal for startup handler */
res = create_pt(exc_pt_sel() + PT_SEL_STARTUP, pd_sel, _tid.ec_sel,
Mtd(Mtd::ESP | Mtd::EIP), (mword_t)_startup_handler);
if (res) {
PERR("could not create startup portal, error = %u\n",
res);
class Create_startup_pt_failed { };
throw Create_startup_pt_failed();
}
res = create_pt(_pt_cleanup, pd_sel, _tid.ec_sel, Mtd(0),
reinterpret_cast<addr_t>(_invoke_handler));
if (res)
PERR("could not create pager cleanup portal, error = %u\n",
res);
}
Pager_object::~Pager_object()
{
/* Revoke portals of Pager_object */
revoke(Obj_crd(exc_pt_sel() + PT_SEL_STARTUP, 0), true);
revoke(Obj_crd(exc_pt_sel() + PT_SEL_PAGE_FAULT, 0), true);
/* Make sure nobody is in the handler anymore by doing an IPC to a
* local cap pointing to same serving thread (if not running in the
* context of the serving thread). When the call returns
* we know that nobody is handled by this object anymore, because
* all remotely available portals had been revoked beforehand.
*/
Utcb *utcb = (Utcb *)Thread_base::myself()->utcb();
if (reinterpret_cast<Utcb *>(&_context->utcb) != utcb) {
utcb->set_msg_word(0);
if (uint8_t res = call(_pt_cleanup))
PERR("failure - cleanup call failed res=%d", res);
}
/* Revoke portal used for the cleanup call */
revoke(Obj_crd(_pt_cleanup, 0), true);
cap_selector_allocator()->free(_pt_cleanup, 0);
}
Pager_capability Pager_entrypoint::manage(Pager_object *obj)
{
/* request creation of portal bind to pager thread */
Native_capability pager_thread_cap(obj->ec_sel());
Native_capability cap_session =
_cap_session->alloc(pager_thread_cap, obj->handler_address());
/* add server object to object pool */
obj->Object_pool<Pager_object>::Entry::cap(cap_session);
insert(obj);
/* return capability that uses the object id as badge */
return reinterpret_cap_cast<Pager_object>(
obj->Object_pool<Pager_object>::Entry::cap());
}
void Pager_entrypoint::dissolve(Pager_object *obj)
{
/* cleanup at cap session */
_cap_session->free(obj->Object_pool<Pager_object>::Entry::cap());
/* cleanup locally */
Native_capability pager_pt =
obj->Object_pool<Pager_object>::Entry::cap();
revoke(pager_pt.dst(), true);
cap_selector_allocator()->free(pager_pt.local_name(), 0);
remove(obj);
}