genode/base-nova/src/core/platform_thread.cc

/*
 * \brief  Thread facility
 * \author Norman Feske
 * \author Sebastian Sumpf
 * \author Alexander Boettcher
 * \date   2009-10-02
 */

/*
 * Copyright (C) 2009-2012 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/printf.h>
#include <base/cap_sel_alloc.h>
#include <base/ipc_pager.h>

/* core includes */
#include <platform_thread.h>
#include <platform_pd.h>
#include <util.h>
#include <nova_util.h>

/* NOVA includes */
#include <nova/syscalls.h>

using namespace Genode;


/*********************
 ** Platform thread **
 *********************/

void Platform_thread::set_cpu(unsigned int cpu_no)
{
	PERR("not yet implemented");
}


int Platform_thread::start(void *ip, void *sp, addr_t exc_base)
{
	using namespace Nova;

	if (!_pager) {
		PERR("pager undefined");
		return -1;
	}

	if (!_pd) {
		PERR("protection domain undefined");
		return -2;
	}

	enum { PD_UTCB = 0x6000000 };
	_pager->initial_eip((addr_t)ip);
	if (!_is_main_thread) {
		addr_t initial_sp = reinterpret_cast<addr_t>(sp);
		addr_t utcb       = round_page(initial_sp);

		_pager->initial_esp(initial_sp);
		if (exc_base == ~0UL) {
			PERR("exception base not specified");
			return -3;
		}

		/**
		 * Create semaphore required for Genode locking.
		 * It is created at the root pager exception base +
		 * SM_SEL_EC_MAIN and can be later on requested by the thread
		 * the same way as STARTUP and PAGEFAULT portal.
		 */
		uint8_t res = Nova::create_sm(_pager->exc_pt_sel() +
		                              SM_SEL_EC_MAIN,
		                              _pd->pd_sel(), 0);
		if (res != Nova::NOVA_OK) {
			PERR("creation of semaphore for new thread failed %u",
			     res);
			return -4;
		}

		/* ip == 0 means that caller will use the thread as worker */
		bool thread_global = ip;
		res = create_ec(_sel_ec(), _pd->pd_sel(), _cpu_no, utcb,
		                initial_sp, exc_base, thread_global);

		if (res)
			PERR("creation of new thread failed %u", res);

		return res ? -5 : 0;
	}

	/*
	 * For the first thread of a new PD, use the initial stack pointer for
	 * reporting the thread's UTCB address.
	 */
	_pager->initial_esp(PD_UTCB + get_page_size());

	addr_t pd_sel       = cap_selector_allocator()->pd_sel();
	addr_t exc_base_sel = cap_selector_allocator()->alloc(Nova::NUM_INITIAL_PT_LOG2);
	addr_t sm_alloc_sel = exc_base_sel + PD_SEL_CAP_LOCK;
	addr_t sm_ec_sel    = exc_base_sel + SM_SEL_EC;

	addr_t remap_src[] = { _pager->exc_pt_sel() + PT_SEL_PAGE_FAULT,
	                       _pd->parent_pt_sel(),
	                       _pager->exc_pt_sel() + PT_SEL_STARTUP };
	addr_t remap_dst[] = { PT_SEL_PAGE_FAULT,
	                       PT_SEL_PARENT,
	                       PT_SEL_STARTUP };

	for (unsigned i = 0; i < sizeof(remap_dst)/sizeof(remap_dst[0]); i++) {
		/* locally map portals to initial portal window */
		if (map_local((Nova::Utcb *)Thread_base::myself()->utcb(),
		              Obj_crd(remap_src[i], 0),
		              Obj_crd(exc_base_sel + remap_dst[i], 0))) {
			PERR("could not remap portal %lx->%lx",
			     remap_src[i], remap_dst[i]);
			return -6;
		}
	}

	/* Create lock for cap allocator selector */
	uint8_t res = Nova::create_sm(sm_alloc_sel, pd_sel, 1);
	if (res != Nova::NOVA_OK) {
		PERR("could not create semaphore for capability allocator");
		return -7;
	}

	/* Create lock for EC used by lock_helper */
	res = Nova::create_sm(sm_ec_sel, pd_sel, 0);
	if (res != Nova::NOVA_OK) {
		PERR("could not create semaphore for new thread");
		return -8;
	}

	/* Create task */
	addr_t pd0_sel = cap_selector_allocator()->alloc();
	_pd->assign_pd(pd0_sel);

	Obj_crd initial_pts(exc_base_sel, Nova::NUM_INITIAL_PT_LOG2);
	res = create_pd(pd0_sel, pd_sel, initial_pts);
	if (res) {
		PERR("create_pd returned %d", res);
		return -9;
	}

	/* Create first thread in task */
	enum { THREAD_GLOBAL = true };
	res = create_ec(_sel_ec(), pd0_sel, _cpu_no, PD_UTCB, 0, 0,
	                THREAD_GLOBAL);
	if (res) {
		PERR("create_ec returned %d", res);
		return -10;
	}

	/* Let the thread run */
	res = create_sc(_sel_sc(), pd0_sel, _sel_ec(), Qpd());
	if (res) {
		PERR("create_sc returned %d", res);
		return -11;
	}

	return 0;
}


void Platform_thread::pause() { PDBG("not implemented"); }


void Platform_thread::resume()
{
	uint8_t res = Nova::create_sc(_sel_sc(), _pd->pd_sel(), _sel_ec(),
	                              Nova::Qpd());
	if (res)
		PDBG("create_sc returned %u", res);
}


int Platform_thread::state(Thread_state *state_dst)
{
	PWRN("not implemented");
	return -1;
}


void Platform_thread::cancel_blocking() { PWRN("not implemented"); }


unsigned long Platform_thread::pager_object_badge() const { return ~0UL; }


Platform_thread::Platform_thread(const char *name, unsigned, int thread_id)
: _pd(0), _id_base(cap_selector_allocator()->alloc(1)), _cpu_no(0) { }


Platform_thread::~Platform_thread()
{
	using namespace Nova;

	if (_is_main_thread)
		revoke(Obj_crd(_pd->pd_sel(), 0));
}