/*

 * syst_np.c - simple cpu-wide counting but forced on a remote CPU

 *

 * Copyright (c) 2009 Google, Inc

 * Contributed by Stephane Eranian <eranian@gmail.com>

 *

 * Based on:

 * Copyright (c) 2002-2006 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.

 */

#include <sys/types.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <sched.h>

#include <err.h>

#include <perfmon/pfmlib.h>

#include <perfmon/perfmon.h>

#include "detect_pmcs.h"

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

#define MAX_EVT_NAME_LEN	128

#define MAX_CPUS	2048

int

pin_cpu(pid_t pid, unsigned int cpu)

{

	cpu_set_t my_set;

        CPU_ZERO(&my_set);

	if (cpu >= MAX_CPUS)

		errx(1, "this program supports only up to %d CPUs", MAX_CPUS);

	CPU_SET(cpu, &my_set);

	return sched_setaffinity(pid, sizeof(cpu_set_t), &my_set);

}

int

main(int argc, char **argv)

{

	char **p;

	pfarg_pmc_t pc[NUM_PMCS];

	pfarg_pmd_t pd[NUM_PMDS];

	uint64_t pdo[NUM_PMDS];

	pfarg_ctx_t ctx[1];

	pfarg_load_t load_args;

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfmlib_options_t pfmlib_options;

	int user_cpu, kern_cpu;

	int ret, ctx_fd;

	unsigned int i, l;

	unsigned int num_counters;

	char name[MAX_EVT_NAME_LEN];

	/*

	 * pass options to library (optional)

	 */

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

	pfmlib_options.pfm_debug = 0; /* set to 1 for debug */

	pfm_set_options(&pfmlib_options);

	/*

	 * Initialize pfm library (required before we can use it)

	 */

	ret = pfm_initialize();

	if (ret != PFMLIB_SUCCESS)

		errx(1, "Cannot initialize library: %s", pfm_strerror(ret));

	pfm_get_num_counters(&num_counters);

	memset(pc, 0, sizeof(pc));

	memset(pd, 0, sizeof(pd));

	memset(pdo, 0, sizeof(pdo));

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

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

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

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

	/*

	 * be nice to user!

	 */

	if (argc > 1) {

		p = argv+1;

		for (i=0; *p ; i++, p++) {

			if (pfm_find_full_event(*p, &inp.pfp_events[i]) != PFMLIB_SUCCESS)

				errx(1, "cannot find %s event", *p);

		}

	} else {

		if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)

			errx(1, "cannot find cycle event");

		if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)

			errx(1, "cannot find inst retired event");

		i = 2;

	}

	/*

	 * set the privilege mode:

	 * 	PFM_PLM3 : user   level

	 * 	PFM_PLM0 : kernel level

	 */

	inp.pfp_dfl_plm   = PFM_PLM3|PFM_PLM0;

	if (i > num_counters) {

		i = num_counters;

		warnx("too many events provided (max=%d events), using first %d event(s)", num_counters, i);

	}

	/*

	 * how many counters we use

	 */

	inp.pfp_event_count = i;

	/*

	 * indicate we are using the monitors for a system-wide session.

	 * This may impact the way the library sets up the PMC values.

	 */

	inp.pfp_flags = PFMLIB_PFP_SYSTEMWIDE;

	/*

	 * In system wide mode, the perfmon context cannot be inherited.

	 * Also in this mode, we cannot use the blocking form of user level notification.

	 */

	ctx[0].ctx_flags = PFM_FL_SYSTEM_WIDE;

	/*

	 * pick a random CPU. Assumes CPU are numbered with no holes

	 */

	srandom(getpid());

	kern_cpu = random() % sysconf(_SC_NPROCESSORS_ONLN);

	user_cpu = (kern_cpu+1) % sysconf(_SC_NPROCESSORS_ONLN);

	/*

	 * The monitored CPU is determined by the processor core

	 * executing the PFM_LOAD_CONTEXT command. To ensure, we

	 * measure the right core, we pin the thread before making

	 * the call.

	 */

	ret = pin_cpu(getpid(), user_cpu);

	if (ret == -1)

		err(1, "cannot set affinity to CPU%d", user_cpu);

	printf("user program pinned to CPU%d\n", user_cpu);

	printf("monitoring CPU%d\n", kern_cpu);

	/*

	 * after the call the task is pinned to which_cpu

	 */

	/*

	 * now create the context for self monitoring/per-task

	 */

	ctx_fd = pfm_create_context(ctx, NULL, NULL, 0);

	if (ctx_fd == -1) {

		if (errno == ENOSYS) {

			errx(1, "your kernel does not have performance monitoring support!\n");

		}

		err(1, "cannot create context");

	}

	/*

	 * build the pfp_unavail_pmcs bitmask by looking

	 * at what perfmon has available. It is not always

	 * the case that all PMU registers are actually available

	 * to applications. For instance, on IA-32 platforms, some

	 * registers may be reserved for the NMI watchdog timer.

	 *

	 * With this bitmap, the library knows which registers NOT to

	 * use. Of source, it is possible that no valid assignement may

	 * be possible if certina PMU registers  are not available.

	 */

	detect_unavail_pmcs(ctx_fd, &inp.pfp_unavail_pmcs);

	/*

	 * let the library figure out the values for the PMCS

	 */

	if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS)

		errx(1, "cannot configure events: %s", pfm_strerror(ret));

	/*

	 * Now prepare the argument to initialize the PMDs and PMCS.

	 * We use pfp_pmc_count to determine the number of PMC to intialize.

	 * We use pfp_pmd_count to determine the number of PMD to initialize.

	 * Some events/features may cause extra PMCs to be used, leading to:

	 * 	- pfp_pmc_count may be >= pfp_event_count

	 * 	- pfp_pmd_count may be >= pfp_event_count

	 */

	for (i=0; i < outp.pfp_pmc_count; i++) {

		pc[i].reg_num   = outp.pfp_pmcs[i].reg_num;

		pc[i].reg_value = outp.pfp_pmcs[i].reg_value;

	}

	for (i=0; i < outp.pfp_pmd_count; i++)

		pd[i].reg_num = outp.pfp_pmds[i].reg_num;

	/*

	 * Now program the registers

	 */

	if (pfm_write_pmcs(ctx_fd, pc, outp.pfp_pmc_count))

		err(1, "pfm_write_pmcs error");

	if (pfm_write_pmds(ctx_fd, pd, outp.pfp_pmd_count))

		err(1, "pfm_write_pmds error");

	/*

	 * in system-wide mode, this field must provide the CPU the caller wants

	 * to monitor. The kernel checks and if calling from the wrong CPU, the

	 * call fails. The affinity is not affected.

	 */

	load_args.load_pid = kern_cpu;

	if (pfm_load_context(ctx_fd, &load_args))

		err(1, "pfm_load_context error");

	printf("<monitoring started on CPU%d, press CTRL-C to quit before 20s time limit>\n", kern_cpu);

	/*

	 * start monitoring

	 */

	if (pfm_start(ctx_fd, NULL) == -1)

		err(1, "pfm_start error");

	for(l=0; l < 10; l++) {

		sleep(2);

		/*

		 * read the results

		 */

		if (pfm_read_pmds(ctx_fd, pd, inp.pfp_event_count))

			err(1, "pfm_read_pmds error");

		/*

		 * print the results

		 */

		puts("------------------------");

		for (i=0; i < inp.pfp_event_count; i++) {

			pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);

			printf("CPU%-2d PMD%-3u raw=%-20"PRIu64" delta=%-20"PRIu64" %s\n",

					kern_cpu,

					pd[i].reg_num,

					pd[i].reg_value,

					pd[i].reg_value - pdo[i],

					name);

			pdo[i] = pd[i].reg_value;

		}

	}

	/*

	 * stop monitoring. 

	 * changed at the user level.

	 */

	if (pfm_stop(ctx_fd))

		err(1, "pfm_stop error");

	/*

	 * destroy everything

	 */

	close(ctx_fd);

	return 0;

}