/*

 * detect_pmu_regs.c - detect unavailable PMD/PMC registers based on perfmon2 information

 *

 * Copyright (c) 2006-2007 Hewlett-Packard Development Company, L.P.

 * Contributed by Stephane Eranian <eranian@hpl.hp.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

 * of the Software, and to permit persons to whom the Software is furnished to do so,

 * subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in all

 * copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE

 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 *

 * This file is part of libpfm, a performance monitoring support library for

 * applications on Linux.

 */

#include <sys/types.h>

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <string.h>

#include <unistd.h>

#include <perfmon/perfmon.h>

#include <perfmon/pfmlib.h>

/*

 * The goal of this function is to help pfm_dispatch_events()

 * in situations where not all PMC/PMD registers are available.

 *

 * It builds bitmasks of *unavailable* PMC/PMD registers.

 * It can use an existing perfmon context file descriptor or if

 * non is passed, it will create a temporary context to retrieve

 * the information.

 *

 * Note that there is no guarantee that the registers marked

 * as available will actually be available by the time the perfmon

 * context is loaded. 

 *

 * arguments:

 * 	fd : a perfmon context file descriptor, or -1

 * 	r_pmcs: a bitmask for PMC availability, NULL if not needed

 * 	r_pmcs: a bitmask for PMD availability, NULL if not needed

 *

 * return:

 * 	-1: invalid file descriptor passed or cannot retrieve information

 * 	 0: success

 */

int

detect_unavail_pmu_regs(int fd, pfmlib_regmask_t *r_pmcs, pfmlib_regmask_t *r_pmds)

{

	pfarg_ctx_t ctx;

	pfarg_setinfo_t	setf;

	int ret, i, j, myfd, max;

	memset(&ctx, 0, sizeof(ctx));

	memset(&setf, 0, sizeof(setf));

	if (r_pmcs)

		memset(r_pmcs, 0, sizeof(*r_pmcs));

	if (r_pmds)

		memset(r_pmds, 0, sizeof(*r_pmds));

	/*

	 * if no context descriptor is passed, then create

	 * a temporary context

	 */

	if (fd == -1) {

		myfd = pfm_create_context(&ctx, NULL, NULL, 0);

		if (myfd == -1)

			return -1;

	} else {

		myfd = fd;

	}

	/*

	 * retrieve available register bitmasks from set0

	 * which is guaranteed to exist for every context

	 *

	 * if myfd is bogus (passed by user) then we return

	 * an error.

	 */

	ret = pfm_getinfo_evtsets(myfd, &setf, 1);

	if (ret == 0) {

		if (r_pmcs) {

			max = PFMLIB_REG_BV < PFM_PMC_BV ? PFMLIB_REG_BV : PFM_PMC_BV;

			for(i=0; i < max; i++) {

				for(j=0; j < 64; j++) {

					if ((setf.set_avail_pmcs[i] & (1ULL << j)) == 0)

						pfm_regmask_set(r_pmcs, (i<<6)+j);

				}

			}

		}

		if (r_pmds) {

			max = PFMLIB_REG_BV < PFM_PMD_BV ? PFMLIB_REG_BV : PFM_PMD_BV;

			for(i=0; i < max; i++) {

				for(j=0; j < 64; j++) {

					if ((setf.set_avail_pmds[i] & (1ULL << j)) == 0)

						pfm_regmask_set(r_pmds, (i<<6)+j);

				}

			}

		}

	}

	if (fd == -1)

		close(myfd);

	return ret;

}