/*
 * ita_dear.c - example of how use the D-EAR 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 <fcntl.h>
#include <sys/mman.h>

#include <perfmon/perfmon.h>
#include <perfmon/perfmon_dfl_smpl.h>
#include <perfmon/pfmlib_itanium.h>

#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS

#define MAX_EVT_NAME_LEN	128
#define MAX_PMU_NAME_LEN	32

#define EVENT_NAME	"DATA_EAR_CACHE_LAT4"
#define SMPL_PERIOD	(40)

#define M_PMD(x)		(1UL<<(x))
#define DEAR_REGS_MASK		(M_PMD(2)|M_PMD(3)|M_PMD(17))

typedef pfm_dfl_smpl_hdr_t	dear_hdr_t;
typedef pfm_dfl_smpl_entry_t	dear_entry_t;
typedef pfm_dfl_smpl_arg_t	smpl_arg_t;

static void *smpl_vaddr;
static unsigned long 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));
}

long
do_test(unsigned long size)
{
    unsigned long i, sum  = 0;
    int *array;

    printf("buffer size %.1fMB\n", (size*sizeof(int))/1024.0);
    array = (int *)malloc(size * sizeof(int));
    if (array == NULL ) {
        printf("buffer size %.1fMB\n", (size*sizeof(int))/1024.0);
        exit(1);
    }
    for(i=0; i<size; i++) {
        array[i]=1;
    }
    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
process_smpl_buffer(void)
{
	dear_hdr_t *hdr;
	dear_entry_t *ent;
	unsigned long pos;
	unsigned long smpl_entry = 0;
	pfm_ita_pmd_reg_t *reg;
	unsigned long i;
	int ret;
	static unsigned long last_ovfl = ~0UL;

	hdr = (dear_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);

	/*
	 * walk through all the entries recored in the buffer
	 */
	for(i=0; i < hdr->hdr_count; i++) {

		ret = 0;

		ent = (dear_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_ita_pmd_reg_t*)(ent+1);

		safe_printf("PMD2 : 0x%016lx\n", reg->pmd_val);

		reg++;

		safe_printf("PMD3 : 0x%016lx, latency %u\n",
			    reg->pmd_val,
			    reg->pmd3_ita_reg.dear_latency);

		reg++;

		safe_printf("PMD17: 0x%016lx, valid %c, address 0x%016lx\n",
				reg->pmd_val,
				reg->pmd17_ita_reg.dear_vl ? 'Y': 'N',
				(reg->pmd17_ita_reg.dear_iaddr << 4) |
				(unsigned long)reg->pmd17_ita_reg.dear_slot);

		/*
		 * move to next entry
		 */
		pos += entry_size;
	}
}

static void
overflow_handler(int n, struct siginfo *info, struct sigcontext *sc)
{
	/* dangerous */
	printf("Notification received\n");

	process_smpl_buffer();
	/*
	 * And resume monitoring
	 */
	if (pfm_restart(id) == -1) {
		perror("pfm_restart");
		exit(1);
	}
}

int
main(void)
{
	pfarg_pmr_t pc[NUM_PMCS];
	pfarg_pmd_attr_t pd[NUM_PMDS];
	pfmlib_input_param_t inp;
	pfmlib_output_param_t outp;
	smpl_arg_t buf_arg;
	pfmlib_options_t pfmlib_options;
	struct sigaction act;
	unsigned int i;
	int ret, type = 0;

	/*
	 * 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
	 */
	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);
	}

	/*
	 * 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 = 1; /* set to 1 for debug */
	pfm_set_options(&pfmlib_options);



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

	/*
	 * To count the number of occurence of this instruction, we must
	 * program a counting monitor with the IA64_TAGGED_INST_RETIRED_PMC8
	 * event.
	 */
	if (pfm_find_full_event(EVENT_NAME, &inp.pfp_events[0]) != PFMLIB_SUCCESS)
		fatal_error("cannot find event %s\n", EVENT_NAME);

	/*
	 * set the (global) privilege mode:
	 * 	PFM_PLM0 : kernel level only
	 */
	inp.pfp_dfl_plm   = PFM_PLM0|PFM_PLM3;

	/*
	 * how many counters we use
	 */
	inp.pfp_event_count = 1;

	/*
	 * let the library figure out the values for the PMCS
	 *
	 * We use all global settings for this EAR.
	 */
	if ((ret=pfm_dispatch_events(&inp, NULL, &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 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 causes 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;
	}

	/*
	 * figure out pmd mapping from output pmc
	 */
	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
	 */
	pd[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY;

	pfm_bv_set(pd[0].reg_smpl_pmds, 2);
	pfm_bv_set(pd[0].reg_smpl_pmds, 3);
	pfm_bv_set(pd[0].reg_smpl_pmds, 17);
	entry_size = sizeof(dear_entry_t) + 3 * 8;

	/*
	 * initialize the PMD and the sampling period
	 */
	pd[0].reg_value       = - SMPL_PERIOD;

	pd[0].reg_long_reset  = - SMPL_PERIOD;
	pd[0].reg_short_reset = - SMPL_PERIOD;

	/*
	 * 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 thann 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_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)
		fatal_error("pfm_write(PMD) error errno %d\n",errno);
	/*
	 * attach session
	 */
	if (pfm_attach(id, 0, getpid()) == -1)
		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(10000);

	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, i.e. which may not be full
	 */
	process_smpl_buffer();

	/*
	 * let's stop this now
	 */
	munmap(smpl_vaddr, (size_t)buf_arg.buf_size);
	close(id);
	return 0;
}
