/*

 * ita_irr.c - example of how to use code range restriction with the Itanium PMU

 *

 * 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.

 *

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

 * applications on Linux/ia64.

 */

#include <sys/types.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <signal.h>

#include <perfmon/perfmon.h>

#include <perfmon/pfmlib_itanium.h>

#define VECTOR_SIZE	1000000UL

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

#define MAX_EVT_NAME_LEN	128

#define MAX_PMU_NAME_LEN	32

typedef struct {

	char *event_name;

	unsigned long expected_value;

}  event_desc_t;

static event_desc_t event_list[]={

	{ "fp_ops_retired_hi", 0UL} ,

	{ "fp_ops_retired_lo", VECTOR_SIZE<<1 },

	{ NULL, 0UL }

};

static void fatal_error(char *fmt,...) __attribute__((noreturn));

static void

fatal_error(char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

	exit(1);

}

void

saxpy(double *a, double *b, double *c, unsigned long size)

{

	unsigned long i;

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

		c[i] = 2*a[i] + b[i];

	}

}

void

saxpy2(double *a, double *b, double *c, unsigned long size)

{

	unsigned long i;

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

		c[i] = 2*a[i] + b[i];

	}

}

static int

do_test(void)

{

	unsigned long size;

	double *a, *b, *c;

	size = VECTOR_SIZE;

	a = malloc(size*sizeof(double));

	b = malloc(size*sizeof(double));

	c = malloc(size*sizeof(double));

	if (a == NULL || b == NULL || c == NULL) fatal_error("Cannot allocate vectors\n");

	memset(a, 0, size*sizeof(double));

	memset(b, 0, size*sizeof(double));

	memset(c, 0, size*sizeof(double));

	saxpy(a,b,c, size);

	saxpy2(a,b,c, size);

	return 0;

}

int

main(int argc, char **argv)

{

	event_desc_t *p;

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfmlib_ita_input_param_t ita_inp;

	pfmlib_ita_output_param_t ita_outp;

	pfarg_pmr_t pd[NUM_PMDS];

	pfarg_pmr_t pc[NUM_PMCS];

	pfarg_pmr_t ibrs[8];

	unsigned long range_start, range_end;

	pfmlib_options_t pfmlib_options;

	struct fd {			/* function descriptor */

		unsigned long addr;

		unsigned long gp;

	} *fd;

	int ret, type = 0;

	unsigned int i;

	int id;

	char name[MAX_EVT_NAME_LEN];

	/*

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

	 */

	ret = pfm_initialize();

	if (ret != PFMLIB_SUCCESS)

		fatal_error("Cannot initialize library: %s\n", pfm_strerror(ret));

	/*

	 * Let's make sure we run this on the right CPU family

	 */

	pfm_get_pmu_type(&type);

	if (type != PFMLIB_ITANIUM_PMU) {

		char model[MAX_PMU_NAME_LEN];

		pfm_get_pmu_name(model, MAX_PMU_NAME_LEN);

		fatal_error("this program does not work with %s PMU\n", model);

	}

	/*

	 * pass options to library (optional)

	 */

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

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

	pfmlib_options.pfm_verbose = 1; /* set to 1 for verbose */

	pfm_set_options(&pfmlib_options);

	/*

	 * Compute the range we are interested in

	 *

	 * On IA-64, the function pointer does not point directly

	 * to the function but to a descriptor which contains two

	 * unsigned long: the first one is the actual start address

	 * of the function, the second is the gp (global pointer)

	 * to load into r1 before jumping into the function. Unlesss

	 * we're jumping into a shared library the gp is the same as

	 * the current gp.

	 *

	 * In the artificial example, we also rely on the compiler/linker

	 * NOT reordering code layout. We depend on saxpy2() being just

	 * after saxpy().

	 *

	 */

	fd = (struct fd *)saxpy;

	range_start = fd->addr;

	fd = (struct fd *)saxpy2;

	range_end   =  fd->addr;

	/*

	 * linker may reorder saxpy() and saxpy2()

	 */

	if (range_end < range_start) {

		unsigned long tmp;

		tmp = range_start;

		range_start = range_end;

		range_end = tmp;

	}

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

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

	memset(ibrs,0, sizeof(ibrs));

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

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

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

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

	/*

	 * find requested event

	 */

	p = event_list;

	for (i=0; p->event_name ; i++, p++) {

		if (pfm_find_event(p->event_name, &inp.pfp_events[i].event) != PFMLIB_SUCCESS)

			fatal_error("Cannot find %s event\n", p->event_name);

	}

	/*

	 * set the privilege mode:

	 * 	PFM_PLM3 : user level only

	 */

	inp.pfp_dfl_plm   = PFM_PLM3;

	/*

	 * how many counters we use

	 */

	inp.pfp_event_count = i;

	/*

	 * We use the library to figure out how to program the debug registers

	 * to cover the data range we are interested in. The rr_end parameter

	 * must point to the byte after the last element of the range (C-style range).

	 *

	 * Because of the masking mechanism and therefore alignment constraints used to implement

	 * this feature, it may not be possible to exactly cover a given range. It may be that

	 * the coverage exceeds the desired range. So it is possible to capture noise if

	 * the surrounding addresses are also heavily used. You can figure out by how much the

	 * actual range is off compared to the requested range by checking the rr_soff and rr_eoff

	 * fields of rr_infos on return from the library call.

	 *

	 * Upon return, the rr_dbr array is programmed and the number of debug registers (not pairs)

	 * used to cover the range is in rr_nbr_used.

	 *

	 */

	ita_inp.pfp_ita_irange.rr_used = 1;	/* indicate we use code range restriction */

	ita_inp.pfp_ita_irange.rr_limits[0].rr_start = range_start;

	ita_inp.pfp_ita_irange.rr_limits[0].rr_end   = range_end;

	/*

	 * let the library figure out the values for the PMCS

	 */

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

		fatal_error("cannot configure events: %s\n", pfm_strerror(ret));

	/*

	 * print offsets

	 */

	printf("code range  : [0x%016lx-0x%016lx)\n"

	       "start_offset:-0x%lx end_offset:+0x%lx\n"

		"%d pairs of debug registers used\n",

			range_start,

			range_end,

			ita_outp.pfp_ita_irange.rr_infos[0].rr_soff,

			ita_outp.pfp_ita_irange.rr_infos[0].rr_eoff,

			ita_outp.pfp_ita_irange.rr_nbr_used >> 1);

	/*

	 * now create the session

	 */

	id = pfm_create(0, NULL);

	if (id == -1) {

		if (errno == ENOSYS)

			fatal_error("Your kernel does not have performance monitoring support!\n");

		fatal_error("cannot create session %s\n", strerror(errno));

	}

	/*

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

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

	 * We must use pfp_event_count to determine the number of PMD to initialize.

	 * Some events cause extra PMCs to be used, so  pfp_pmc_count may be >= pfp_event_count.

	 *

	 * This step is new compared to libpfm-2.x. It is necessary because the library no

	 * longer knows about the kernel data structures.

	 */

	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;

	}

	/*

	 * propagate the setup for the debug registers from the library to the arguments

	 * to the syscall. The library does not know the type of the syscall

	 * anymore. IBRs are mapped to PMC256-PMC263

	 */

	for (i=0; i < ita_outp.pfp_ita_drange.rr_nbr_used; i++) {

		ibrs[i].reg_num   = 256+ita_outp.pfp_ita_irange.rr_br[i].reg_num;

		ibrs[i].reg_value = ita_outp.pfp_ita_irange.rr_br[i].reg_value;

	}

	/*

	 * Program the code debug registers.

	 *

	 * IMPORTANT: programming the debug register MUST always be done before the PMCs

	 * otherwise the kernel will fail on PFM_WRITE_PMCS. This is for security reasons.

	 */

	if (pfm_write(id, 0, PFM_RW_PMC, ibrs, ita_outp.pfp_ita_irange.rr_nbr_used * sizeof(*ibrs)) == -1)

		fatal_error("pfm_write error errno %d\n",errno);

	/*

	 * Now program the registers

	 *

	 * We don't use the save variable to indicate the number of elements passed to

	 * the kernel because, as we said earlier, pc may contain more elements than

	 * the number of events we specified, i.e., contains more than coutning monitors.

	 */

	if (pfm_write(id, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)

		fatal_error("pfm_write error errno %d\n",errno);

	if (pfm_write(id, 0, PFM_RW_PMD, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)

		fatal_error("pfm_write(PMD) error errno %d\n",errno);

	/*

	 * now attach session

	 */

	if (pfm_attach(id, 0, getpid()) == -1)

		fatal_error("pfm_attach error errno %d\n",errno);

	/*

	 * Let's roll now.

	 *

	 * We run two distinct copies of the same function but we restrict measurement

	 * to the first one (saxpy). Therefore the expected count is half what you would

	 * get if code range restriction was not used. The core loop in both case uses

	 * two floating point operation per iteration.

	 */

	if (pfm_set_state(id, 0, PFM_ST_START))

		fatal_error("pfm_set_state error errno %d\n",errno);

	do_test();

	if (pfm_set_state(id, 0, PFM_ST_STOP))

		fatal_error("pfm_set_state error errno %d\n",errno);

	/*

	 * now read the results

	 */

	if (pfm_read(id, 0, PFM_RW_PMD, pd, inp.pfp_event_count * sizeof(*pd)) == -1)

		fatal_error("pfm_read error errno %d\n",errno);

	/*

	 * print the results

	 *

	 * It is important to realize, that the first event we specified may not

	 * be in PMD4. Not all events can be measured by any monitor. That's why

	 * we need to use the pc[] array to figure out where event i was allocated.

	 */

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

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

		printf("PMD%-3u %20lu %s (expected %lu)\n",

			pd[i].reg_num,

			pd[i].reg_value,

			name,

			event_list[i].expected_value);

	}

	/*

	 * let's stop this now

	 */

	close(id);

	return 0;

}