/* * \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 #include #include /* NOVA includes */ #include using namespace Genode; using namespace Nova; enum { PF_HANDLER_STACK_SIZE = 4096 }; 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(myself); int ret = obj->pager(ipc_pager); if (ret) { PWRN("page-fault resolution for address 0x%lx, ip=0x%lx failed", ipc_pager.fault_addr(), ipc_pager.fault_ip()); /* revoke paging capability */ Nova::revoke(Nova::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(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(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) utcb->append_item(Obj_crd(obj->exc_pt_sel() + event, 0), 0); 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) { addr_t pd_sel = cap_selector_allocator()->pd_sel(); enum { CPU_NO = 0, GLOBAL = false, EXC_BASE = 0 }; mword_t *thread_sp = (mword_t *)&_context->stack[-4]; mword_t thread_utcb = (mword_t) &_context->utcb; /* create local EC */ uint8_t res = create_ec(_tid.ec_sel, pd_sel, CPU_NO, thread_utcb, (mword_t)thread_sp, /* <- delivered to the startup handler */ EXC_BASE, GLOBAL); if (res) PERR("create_ec returned %d - utcb 0x%lx", res, thread_utcb); /* create portal for page-fault handler */ 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, create_pt returned %d\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, create_pt returned %d\n", res); class Create_startup_pt_failed { }; throw Create_startup_pt_failed(); } /* * Create object identity representing the pager object. It is used as * argument to 'Cpu_session::set_pager'. Furthermore it can be invoked to * request the mapping of the event capability selector window * corresponding to the pager object. */ _pt_sel = cap_selector_allocator()->alloc(); res = create_pt(_pt_sel, pd_sel, _tid.ec_sel, Mtd(0), (mword_t)_invoke_handler); if (res) PERR("could not create pager object identity, create_pt returned %d\n", res); _pt_cleanup = cap_selector_allocator()->alloc(); res = create_pt(_pt_cleanup, pd_sel, _tid.ec_sel, Mtd(0), (mword_t)_invoke_handler); if (res) PERR("could not create pager cleanup portal, create_pt returned %d\n", res); } Pager_object::~Pager_object() { /* Revoke thread portals serving exceptions */ revoke(Obj_crd(exc_pt_sel(), NUM_INITIAL_PT_LOG2), true); /* Revoke portal used as identity object */ revoke(Obj_crd(_pt_sel, 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(&_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_sel, 0); cap_selector_allocator()->free(_pt_cleanup, 0); } Pager_capability Pager_entrypoint::manage(Pager_object *obj) { /* supplement capability with object ID obtained from CAP session */ obj->Object_pool::Entry::cap(_cap_session->alloc(Native_capability(obj->pt_sel(), 0))); /* add server object to object pool */ insert(obj); /* return capability that uses the object id as badge */ return reinterpret_cap_cast(obj->Object_pool::Entry::cap()); } void Pager_entrypoint::dissolve(Pager_object *obj) { /* cleanup cap session */ _cap_session->free(obj->Object_pool::Entry::cap()); if (obj->pt_sel() != 0UL + obj->Object_pool::Entry::cap().dst()) { cap_selector_allocator()->free(obj->Object_pool::Entry::cap().dst(), 0); revoke(Obj_crd(obj->Object_pool::Entry::cap().dst(), 0), true); } remove(obj); }