/*

 * mont_btb.c - example of how use the ETB with the Dual-Core Itanium 2 PMU

 *

 * Copyright (c) 2005-2006 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.

 */

#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 <fcntl.h>

#include <sys/mman.h>

#include <perfmon/perfmon.h>

#include <perfmon/perfmon_dfl_smpl.h>

#include <perfmon/pfmlib_montecito.h>

typedef pfm_dfl_smpl_hdr_t	etb_hdr_t;

typedef pfm_dfl_smpl_entry_t	etb_entry_t;

typedef pfm_dfl_smpl_arg_t	smpl_arg_t;

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

#define MAX_EVT_NAME_LEN	128

#define MAX_PMU_NAME_LEN	32

/*

 * The ETB_EVENT is increment by 1 for each branch event. Such event is composed of

 * two entries in the ETB: a source and a target entry. The ETB is full after 4 branch

 * events.

 */

#define SMPL_PERIOD	(4UL*256)

/*

 * We use a small buffer size to exercise the overflow handler

 */

#define SMPL_BUF_NENTRIES	64

static void *smpl_vaddr;

static size_t entry_size;

static int id;

#define BPL (sizeof(uint64_t)<<3)

#define LBPL	6

static inline void pfm_bv_set(uint64_t *bv, uint16_t rnum)

{

	bv[rnum>>LBPL] |= 1UL << (rnum&(BPL-1));

}

/*

 * we don't use static to make sure the compiler does not inline the function

 */

long func1(void) { return random();}

long func2(void) { return random();}

long

do_test(unsigned long loop)

{

	long sum  = 0;

	while(loop--) {

		if (loop & 0x1)

			sum += func1();

		else

			sum += loop + func2();

	}

	return sum;

}

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);

}

/*

 * print content of sampling buffer

 *

 * XXX: using stdio to print from a signal handler is not safe with multi-threaded

 * applications

 */

#define safe_printf	printf

static void

show_etb_reg(int j, pfm_mont_pmd_reg_t reg, pfm_mont_pmd_reg_t pmd39)

{

	unsigned long bruflush, b1, etb_ext;

	unsigned long addr;

	int is_valid;

	is_valid = reg.pmd48_63_etb_mont_reg.etb_s == 0 && reg.pmd48_63_etb_mont_reg.etb_mp == 0 ? 0 : 1;

	/*

	 * the joy of the ETB extension register layout!

	 */

	if (j < 8)

		etb_ext = (pmd39.pmd_val>>(8*j)) & 0xf;

	else

		etb_ext = (pmd39.pmd_val>>(4+8*(j-8))) & 0xf;

	b1       = etb_ext & 0x1;

	bruflush = (etb_ext >> 1) & 0x1;

	safe_printf("\tPMD%-2d: 0x%016lx s=%d mp=%d bru=%ld b1=%ld valid=%c\n",

		j+48,

		reg.pmd_val,

		reg.pmd48_63_etb_mont_reg.etb_s,

		reg.pmd48_63_etb_mont_reg.etb_mp,

		bruflush, b1,

		is_valid ? 'Y' : 'N');

	if (!is_valid) return;

	if (reg.pmd48_63_etb_mont_reg.etb_s) {

		addr = (reg.pmd48_63_etb_mont_reg.etb_addr+b1)<<4;

		addr |= reg.pmd48_63_etb_mont_reg.etb_slot < 3 ? reg.pmd48_63_etb_mont_reg.etb_slot : 0;

		safe_printf("\t       Source Address: 0x%016lx\n"

			    "\t       Taken=%c Prediction:%s\n\n",

			 addr,

			 reg.pmd48_63_etb_mont_reg.etb_slot < 3 ? 'Y' : 'N',

			 reg.pmd48_63_etb_mont_reg.etb_mp ? "FE Failure" : 

			 bruflush ? "BE Failure" : "Success");

	} else {

		safe_printf("\t       Target Address:0x%016lx\n\n",

			 (unsigned long)(reg.pmd48_63_etb_mont_reg.etb_addr<<4));

	}

}

static void

show_etb(pfm_mont_pmd_reg_t *etb)

{

	int i, last;

	pfm_mont_pmd_reg_t pmd38, pmd39;

	pmd38.pmd_val = etb[0].pmd_val;

	pmd39.pmd_val = etb[1].pmd_val;

	i    = pmd38.pmd38_mont_reg.etbi_full ? pmd38.pmd38_mont_reg.etbi_ebi : 0;

	last = pmd38.pmd38_mont_reg.etbi_ebi;

	safe_printf("btb_trace: i=%d last=%d bbi=%d full=%d\n",

		i,

		last,

		pmd38.pmd38_mont_reg.etbi_ebi,

		pmd38.pmd38_mont_reg.etbi_full);

	/*

	 * i+2 = skip over PMD38/pmd39

	 */

	do {

		show_etb_reg(i, etb[i+2], pmd39);

		i = (i+1) % 16;

	} while (i != last);

}

void

process_smpl_buffer(void)

{

	etb_hdr_t	*hdr;

	etb_entry_t	*ent;

	unsigned long pos;

	unsigned long smpl_entry = 0;

	pfm_mont_pmd_reg_t *reg;

	size_t count;

	static unsigned long last_ovfl = ~0UL;

	hdr = (etb_hdr_t *)smpl_vaddr;

	/*

	 * check that we are not diplaying the previous set of samples again.

	 * Required to take care of the last batch of samples.

	 */

	if (hdr->hdr_overflows <= last_ovfl && last_ovfl != ~0UL) {

		printf("skipping identical set of samples %lu <= %lu\n", hdr->hdr_overflows, last_ovfl);

		return;

	}

	pos = (unsigned long)(hdr+1);

	count = hdr->hdr_count;

	/*

	 * walk through all the entries recored in the buffer

	 */

	while(count--) {

		ent = (etb_entry_t *)pos;

		/*

		 * print entry header

		 */

		safe_printf("Entry %ld PID:%d TID:%d CPU:%d STAMP:0x%lx IIP:0x%016lx\n",

			smpl_entry++,

			ent->tgid,

			ent->pid,

			ent->cpu,

			ent->tstamp,

			ent->ip);

		/*

		 * point to first recorded register (always contiguous with entry header)

		 */

		reg = (pfm_mont_pmd_reg_t*)(ent+1);

		/*

		 * in this particular example, we have pmd48-pmd63 has the ETB. We have also

		 * included pmd38/pmd39 (ETB index and extenseion) has part of the registers

		 * to record. This trick allows us to get the index to decode the sequential

		 * order of the ETB.

		 *

		 * Recorded registers are always recorded in increasing index order. So we know

		 * that where to find pmd38/pmd39.

		 */

		show_etb(reg);

		/*

		 * move to next entry

		 */

		pos += entry_size;

	}

}

static void

overflow_handler(int n, struct siginfo *info, struct sigcontext *sc)

{

	process_smpl_buffer();

	/*

	 * And resume monitoring

	 */

	if (pfm_restart(id))

		fatal_error("pfm_restart errno %d\n", errno);

}

int

main(void)

{

	int ret;

	int type = 0;

	pfarg_pmr_t pc[NUM_PMCS];

	pfarg_pmd_attr_t pd[NUM_PMDS];

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfmlib_mont_input_param_t mont_inp;

	smpl_arg_t buf_arg;

	pfmlib_options_t pfmlib_options;

	struct sigaction act;

	unsigned int i;

	/*

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

	 */

	if (pfm_initialize() != PFMLIB_SUCCESS)

		fatal_error("Can't initialize library\n");

	/*

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

	 */

	pfm_get_pmu_type(&type);

	if (type != PFMLIB_MONTECITO_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);

	}

	/*

	 * Install the overflow handler (SIGIO)

	 */

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

	act.sa_handler = (sig_t)overflow_handler;

	sigaction (SIGIO, &act, 0);

	/*

	 * 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 = 0; /* set to 1 for debug */

	pfm_set_options(&pfmlib_options);

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

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

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

	/*

	 * prepare parameters to library. we don't use any Itanium

	 * specific features here. so the pfp_model is NULL.

	 */

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

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

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

	/*

	 * Before calling pfm_find_dispatch(), we must specify what kind

	 * of branches we want to capture. We are interested in all taken

	 * branches * therefore we program we set the various fields to:

	 */

	mont_inp.pfp_mont_etb.etb_used = 1;

	mont_inp.pfp_mont_etb.etb_tm  = 0x2;

	mont_inp.pfp_mont_etb.etb_ptm = 0x3;

	mont_inp.pfp_mont_etb.etb_ppm = 0x3;

	mont_inp.pfp_mont_etb.etb_brt = 0x0;

	mont_inp.pfp_mont_etb.etb_plm = PFM_PLM3;

	if (pfm_find_full_event("ETB_EVENT", &inp.pfp_events[0]) != PFMLIB_SUCCESS)

		fatal_error("cannot find event ETB_EVENT\n");

	/*

	 * set the (global) privilege mode:

	 * 	PFM_PLM3 : user level only

	 */

	inp.pfp_dfl_plm   = PFM_PLM3;

	/*

	 * how many counters we use

	 */

	inp.pfp_event_count = 1;

	/*

	 * let the library figure out the values for the PMCS

	 */

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

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

	/*

	 * the size of the buffer is indicated in bytes (not entries).

	 *

	 * The kernel will record into the buffer up to a certain point.

	 * No partial samples are ever recorded.

	 */

	buf_arg.buf_size = getpagesize();

	/*

	 * now create the session

	 */

	id = pfm_create(PFM_FL_SMPL_FMT, NULL, "default", &buf_arg, sizeof(buf_arg));

	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));

	}

	/*

	 * retrieve the virtual address at which the sampling

	 * buffer has been mapped

	 */

	smpl_vaddr = mmap(NULL, (size_t)buf_arg.buf_size, PROT_READ, MAP_PRIVATE, id, 0);

	if (smpl_vaddr == MAP_FAILED)

		fatal_error("cannot mmap sampling buffer errno %d\n", errno);

	printf("Sampling buffer mapped at %p\n", smpl_vaddr);

	/*

	 * 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.

	 */

	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;

	}

	/*

	 * figure out pmd mapping from output pmc

	 * PMD38 is part of the set of used PMD returned by libpfm.

	 * It will be reset automatically

	 */

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

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

	/*

	 * indicate we want notification when buffer is full and randomization

	 */

	pd[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY | PFM_REGFL_RANDOM;

	/*

	 * Now prepare the argument to initialize the PMD and the sampling period

	 * We know we use only one PMD in this case, therefore pmd[0] corresponds

	 * to our first event which is our sampling period.

	 */

	pd[0].reg_value       = - SMPL_PERIOD;

	pd[0].reg_long_reset  = - SMPL_PERIOD;

	pd[0].reg_short_reset = - SMPL_PERIOD;

	/*

	 * populate our smpl_pmds bitmask to include all of the ETB PMDs,

	 * including index, extensions

	 */

	pfm_bv_set(pd[0].reg_smpl_pmds, 38);

	pfm_bv_set(pd[0].reg_smpl_pmds, 39);

	entry_size = sizeof(etb_entry_t) + 2 * 8;

	for(i=48; i < 64; i++) {

		pfm_bv_set(pd[0].reg_smpl_pmds, i);

		entry_size += 8;

	}

	/*

	 * When our counter overflows, we want to ETB index to be reset, so that we keep

	 * in sync. 

	 */

	pfm_bv_set(pd[0].reg_reset_pmds, 38);

	/*

	 * Now program the registers

	 */

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

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

	if (pfm_write(id, 0, PFM_RW_PMD_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)))

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

	/*

	 * now we attach session

	 */

	if (pfm_attach(id, 0, getpid()))

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

	/*

	 * setup asynchronous notification on the file descriptor

	 */

	ret = fcntl(id, F_SETFL, fcntl(id, F_GETFL, 0) | O_ASYNC);

	if (ret == -1)

		fatal_error("cannot set ASYNC: %s\n", strerror(errno));

	/*

	 * get ownership of the descriptor

	 */

	ret = fcntl(id, F_SETOWN, getpid());

	if (ret == -1)

		fatal_error("cannot setown: %s\n", strerror(errno));

	/*

	 * Let's roll now.

	 */

	if (pfm_set_state(id, 0, PFM_ST_START))

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

	do_test(1000);

	if (pfm_set_state(id, 0, PFM_ST_STOP))

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

	/*

	 * We must call the processing routine to cover the last entries recorded

	 * in the sampling buffer. Note that the buffer may not be full at this point.

	 *

	 */

	process_smpl_buffer();

	/*

	 * let's stop this now

	 */

	munmap(smpl_vaddr, (size_t)buf_arg.buf_size);

	close(id);

	return 0;

}