/*
 * perf_util.c - helper functions for perf_events
 *
 * Copyright (c) 2009 Google, Inc
 * Contributed by Stephane Eranian <eranian@gmail.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 <string.h>
#include <unistd.h>
#include <err.h>

#include <perfmon/pfmlib_perf_event.h>
#include "perf_util.h"

/* the **fd parameter must point to a null pointer on the first call
 * max_fds and num_fds must both point to a zero value on the first call
 * The return value is success (0) vs. failure (non-zero)
 */
int
perf_setup_argv_events(const char **argv, perf_event_desc_t **fds, int *num_fds)
{
	perf_event_desc_t *fd;
	pfm_perf_encode_arg_t arg;
	int new_max, ret, num, max_fds;
	int group_leader;

	if (!(argv && fds && num_fds))
		return -1;

	fd = *fds;
	if (fd) {
		max_fds = fd[0].max_fds;
		if (max_fds < 2)
			return -1;
		num = *num_fds;
	} else {
		max_fds = num = 0; /* bootstrap */
	}
	group_leader = num;

	while(*argv) {
		if (num == max_fds) {
			if (max_fds == 0)
				new_max = 2;
			else
				new_max = max_fds << 1;

			if (new_max < max_fds) {
				warn("too many entries");
				goto error;
			}
			fd = realloc(fd, new_max * sizeof(*fd));
			if (!fd) {
				warn("cannot allocate memory");
				goto error;
			}
			/* reset newly allocated chunk */
			memset(fd + max_fds, 0, (new_max - max_fds) * sizeof(*fd));
			max_fds = new_max;

			/* update max size */
			fd[0].max_fds = max_fds;
		}
		/* ABI compatibility, set before calling libpfm */
		fd[num].hw.size = sizeof(fd[num].hw);

		memset(&arg, 0, sizeof(arg));
		arg.attr = &fd[num].hw;
		arg.fstr = &fd[num].fstr; /* fd[].fstr is NULL */

		ret = pfm_get_os_event_encoding(*argv, PFM_PLM0|PFM_PLM3, PFM_OS_PERF_EVENT_EXT, &arg);
		if (ret != PFM_SUCCESS) {
			warnx("event %s: %s", *argv, pfm_strerror(ret));
			goto error;
		}

		fd[num].name = strdup(*argv);
		fd[num].group_leader = group_leader;
		fd[num].idx = arg.idx;
		fd[num].cpu = arg.cpu;

		num++;
		argv++;
	}
	*num_fds = num;
	*fds = fd;
	return 0;
error:
	perf_free_fds(fd, num);
	return -1;
}

int
perf_setup_list_events(const char *ev, perf_event_desc_t **fd, int *num_fds)
{
	const char **argv;
	char *p, *q, *events;
	int i, ret, num = 0;

	if (!(ev && fd && num_fds))
		return -1;

	events = strdup(ev);
	if (!events)
		return -1;

	q = events;
	while((p = strchr(q, ','))) {
		num++;
		q = p + 1;
	}
	num++;
	num++; /* terminator */

	argv = malloc(num * sizeof(char *));
	if (!argv) {
		free(events);
		return -1;
	}

	i = 0; q = events;
	while((p = strchr(q, ','))) {
		*p = '\0';
		argv[i++] = q;
		q = p + 1;
	}
	argv[i++] = q;
	argv[i] = NULL;

	ret = perf_setup_argv_events(argv, fd, num_fds);
	free(argv);
	free(events); /* strdup in perf_setup_argv_events() */
	return ret;
}

void
perf_free_fds(perf_event_desc_t *fds, int num_fds)
{
	int i;

	for (i = 0 ; i < num_fds; i++) {
		free(fds[i].name);
		free(fds[i].fstr);
	}
	free(fds);
}

int
perf_get_group_nevents(perf_event_desc_t *fds, int num, int idx)
{
	int leader;
	int i;

	if (idx < 0 || idx >= num)
		return 0;

	leader = fds[idx].group_leader;

	for (i = leader + 1; i < num; i++) {
		if (fds[i].group_leader != leader) {
			/* This is a new group leader, so the previous
			 * event was the final event of the preceding
			 * group.
			 */
			return i - leader;
		}
	}
	return i - leader;
}

int
perf_read_buffer(perf_event_desc_t *hw, void *buf, size_t sz)
{
	struct perf_event_mmap_page *hdr = hw->buf;
	size_t pgmsk = hw->pgmsk;
	void *data;
	unsigned long tail;
	size_t avail_sz, m, c;
	
	/*
	 * data points to beginning of buffer payload
	 */
	data = ((void *)hdr)+sysconf(_SC_PAGESIZE);

	/*
	 * position of tail within the buffer payload
	 */
	tail = hdr->data_tail & pgmsk;

	/*
	 * size of what is available
	 *
	 * data_head, data_tail never wrap around
	 */
	avail_sz = hdr->data_head - hdr->data_tail;
	if (sz > avail_sz)
		return -1;

	/*
	 * sz <= avail_sz, we can satisfy the request
	 */

	/*
	 * c = size till end of buffer
	 *
	 * buffer payload size is necessarily
	 * a power of two, so we can do:
	 */
	c = pgmsk + 1 -  tail;

	/*
	 * min with requested size
	 */
	m = c < sz ? c : sz;

	/* copy beginning */
	memcpy(buf, data+tail, m);

	/*
	 * copy wrapped around leftover
	 */
	if (sz > m)
		memcpy(buf+m, data, sz - m);

	//printf("\nhead=%lx tail=%lx new_tail=%lx sz=%zu\n", hdr->data_head, hdr->data_tail, hdr->data_tail+sz, sz);
	hdr->data_tail += sz;

	return 0;
}

void
perf_skip_buffer(perf_event_desc_t *hw, size_t sz)
{
	struct perf_event_mmap_page *hdr = hw->buf;

	if ((hdr->data_tail + sz) > hdr->data_head)
		sz = hdr->data_head - hdr->data_tail;

	hdr->data_tail += sz;
}

static size_t
__perf_handle_raw(perf_event_desc_t *hw)
{
	size_t sz = 0;
	uint32_t raw_sz, i;
	char *buf;
	int ret;

	ret = perf_read_buffer_32(hw, &raw_sz);
	if (ret) {
		warnx("cannot read raw size");
		return -1;
	}

	sz += sizeof(raw_sz);

	printf("\n\tRAWSZ:%u\n", raw_sz);

	buf = malloc(raw_sz);
	if (!buf) {
		warn("cannot allocate raw buffer");
		return -1;
	}


	ret = perf_read_buffer(hw, buf, raw_sz);
	if (ret) {
		warnx("cannot read raw data");
		free(buf);
		return -1;
	}

	if (raw_sz)
		putchar('\t');

	for(i=0; i < raw_sz; i++) {
		printf("0x%02x ", buf[i] & 0xff );
		if (((i+1) % 16)  == 0)
			printf("\n\t");
	}
	if (raw_sz)
		putchar('\n');

	free(buf);

	return sz + raw_sz;
}

static int
perf_display_branch_stack(perf_event_desc_t *desc, FILE *fp)
{
	struct perf_branch_entry b;
	uint64_t nr, n;
	int ret;

	ret = perf_read_buffer(desc, &n, sizeof(n));
	if (ret)
		errx(1, "cannot read branch stack nr");

	fprintf(fp, "\n\tBRANCH_STACK:%"PRIu64"\n", n);
	nr = n;
	/*
	 * from most recent to least recent take branch
	 */
	while (nr--) {
		ret = perf_read_buffer(desc, &b, sizeof(b));
		if (ret)
			errx(1, "cannot read branch stack entry");

		fprintf(fp, "\tFROM:0x%016"PRIx64" TO:0x%016"PRIx64" MISPRED:%c\n",
			b.from,
			b.to,
			!(b.mispred || b.predicted) ? '-':
			(b.mispred ? 'Y' :'N'));
	}
	return (int)(n * sizeof(b) + sizeof(n));
}

static int
perf_display_regs_user(perf_event_desc_t *hw, FILE *fp)
{
	errx(1, "display regs_user not implemented yet\n");
	return 0;
}

static int
perf_display_regs_intr(perf_event_desc_t *hw, FILE *fp)
{
	errx(1, "display regs_intr not implemented yet\n");
	return 0;
}

static int
perf_display_stack_user(perf_event_desc_t *hw, FILE *fp)
{
	uint64_t nr;
	char buf[512];
	size_t sz;
	int ret;

	ret = perf_read_buffer(hw, &nr, sizeof(nr));
	if (ret)
		errx(1, "cannot user stack size");

	fprintf(fp, "USER_STACK: SZ:%"PRIu64"\n", nr);

	/* consume content */
	while (nr) {
		sz = nr;
		if (sz > sizeof(buf))
			sz = sizeof(buf);

		ret = perf_read_buffer(hw, buf, sz);
		if (ret)
			errx(1, "cannot user stack content");
		nr -= sz;
	}

	return 0;
}

int
perf_display_sample(perf_event_desc_t *fds, int num_fds, int idx, struct perf_event_header *ehdr, FILE *fp)
{
	perf_event_desc_t *hw;
	struct { uint32_t pid, tid; } pid;
	struct { uint64_t value, id; } grp;
	uint64_t time_enabled, time_running;
	size_t sz;
	uint64_t type, fmt;
	uint64_t val64;
	const char *str;
	int ret, e;

	if (!fds || !fp || !ehdr  || num_fds < 0 || idx < 0 ||  idx >= num_fds)
		return -1;

	sz = ehdr->size - sizeof(*ehdr);

	hw = fds+idx;

	type = hw->hw.sample_type;
	fmt  = hw->hw.read_format;

	if (type & PERF_SAMPLE_IDENTIFIER) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx("cannot read IP");
			return -1;
		}
		fprintf(fp, "ID:%"PRIu64" ", val64);
		sz -= sizeof(val64);
	}
	/*
	 * the sample_type information is laid down
	 * based on the PERF_RECORD_SAMPLE format specified
	 * in the perf_event.h header file.
	 * That order is different from the enum perf_event_sample_format
	 */
	if (type & PERF_SAMPLE_IP) {
		const char *xtra = " ";
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx("cannot read IP");
			return -1;
		}

		/*
		 * MISC_EXACT_IP indicates that kernel is returning
		 * th  IIP of an instruction which caused the event, i.e.,
		 * no skid
		 */
		if (hw->hw.precise_ip && (ehdr->misc & PERF_RECORD_MISC_EXACT_IP))
			xtra = " (exact) ";

		fprintf(fp, "IIP:%#016"PRIx64"%s", val64, xtra);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_TID) {
		ret = perf_read_buffer(hw, &pid, sizeof(pid));
		if (ret) {
			warnx( "cannot read PID");
			return -1;
		}

		fprintf(fp, "PID:%d TID:%d ", pid.pid, pid.tid);
		sz -= sizeof(pid);
	}

	if (type & PERF_SAMPLE_TIME) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read time");
			return -1;
		}

		fprintf(fp, "TIME:%'"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_ADDR) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read addr");
			return -1;
		}

		fprintf(fp, "ADDR:%#016"PRIx64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_ID) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read id");
			return -1;
		}

		fprintf(fp, "ID:%"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_STREAM_ID) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read stream_id");
			return -1;
		}
		fprintf(fp, "STREAM_ID:%"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_CPU) {
		struct { uint32_t cpu, reserved; } cpu;
		ret = perf_read_buffer(hw, &cpu, sizeof(cpu));
		if (ret) {
			warnx( "cannot read cpu");
			return -1;
		}
		fprintf(fp, "CPU:%u ", cpu.cpu);
		sz -= sizeof(cpu);
	}

	if (type & PERF_SAMPLE_PERIOD) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read period");
			return -1;
		}
		fprintf(fp, "PERIOD:%'"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	/* struct read_format {
	 * 	{ u64		value;
	 * 	  { u64		time_enabled; } && PERF_FORMAT_ENABLED
	 * 	  { u64		time_running; } && PERF_FORMAT_RUNNING
	 * 	  { u64		id;           } && PERF_FORMAT_ID
	 * 	} && !PERF_FORMAT_GROUP
	 *
	 * 	{ u64		nr;
	 * 	  { u64		time_enabled; } && PERF_FORMAT_ENABLED
	 * 	  { u64		time_running; } && PERF_FORMAT_RUNNING
	 * 	  { u64		value;
	 * 	    { u64	id;           } && PERF_FORMAT_ID
	 * 	  }		cntr[nr];
	 * 	} && PERF_FORMAT_GROUP
	 * };
	 */
	if (type & PERF_SAMPLE_READ) {
		uint64_t values[3];
		uint64_t nr;

		if (fmt & PERF_FORMAT_GROUP) {
			ret = perf_read_buffer_64(hw, &nr);
			if (ret) {
				warnx( "cannot read nr");
				return -1;
			}

			sz -= sizeof(nr);

			time_enabled = time_running = 1;

			if (fmt & PERF_FORMAT_TOTAL_TIME_ENABLED) {
				ret = perf_read_buffer_64(hw, &time_enabled);
				if (ret) {
					warnx( "cannot read timing info");
					return -1;
				}
				sz -= sizeof(time_enabled);
			}

			if (fmt & PERF_FORMAT_TOTAL_TIME_RUNNING) {
				ret = perf_read_buffer_64(hw, &time_running);
				if (ret) {
					warnx( "cannot read timing info");
					return -1;
				}
				sz -= sizeof(time_running);
			}

			fprintf(fp, "ENA=%'"PRIu64" RUN=%'"PRIu64" NR=%"PRIu64"\n", time_enabled, time_running, nr);

			values[1] = time_enabled;
			values[2] = time_running;
			while(nr--) {
				grp.id = -1;
				ret = perf_read_buffer_64(hw, &grp.value);
				if (ret) {
					warnx( "cannot read group value");
					return -1;
				}
				sz -= sizeof(grp.value);

				if (fmt & PERF_FORMAT_ID) {
					ret = perf_read_buffer_64(hw, &grp.id);
					if (ret) {
						warnx( "cannot read leader id");
						return -1;
					}
					sz -= sizeof(grp.id);
				}

				e = perf_id2event(fds, num_fds, grp.id);
				if (e == -1)
					str = "unknown sample event";
				else
					str = fds[e].name;

				values[0] = grp.value;
				grp.value = perf_scale(values);

				fprintf(fp, "\t%'"PRIu64" %s (%"PRIu64"%s)\n",
					grp.value, str,
					grp.id,
					time_running != time_enabled ? ", scaled":"");

			}
		} else {
			time_enabled = time_running = 0;
			/*
			 * this program does not use FORMAT_GROUP when there is only one event
			 */
			ret = perf_read_buffer_64(hw, &val64);
			if (ret) {
				warnx( "cannot read value");
				return -1;
			}
			sz -= sizeof(val64);

			if (fmt & PERF_FORMAT_TOTAL_TIME_ENABLED) {
				ret = perf_read_buffer_64(hw, &time_enabled);
				if (ret) {
					warnx( "cannot read timing info");
					return -1;
				}
				sz -= sizeof(time_enabled);
			}

			if (fmt & PERF_FORMAT_TOTAL_TIME_RUNNING) {
				ret = perf_read_buffer_64(hw, &time_running);
				if (ret) {
					warnx( "cannot read timing info");
					return -1;
				}
				sz -= sizeof(time_running);
			}
			if (fmt & PERF_FORMAT_ID) {
				ret = perf_read_buffer_64(hw, &val64);
				if (ret) {
					warnx( "cannot read leader id");
					return -1;
				}
				sz -= sizeof(val64);
			}

			fprintf(fp, "ENA=%'"PRIu64" RUN=%'"PRIu64"\n", time_enabled, time_running);

			values[0] = val64;
			values[1] = time_enabled;
			values[2] = time_running;
			val64 = perf_scale(values);

			fprintf(fp, "\t%'"PRIu64" %s %s\n",
				val64, fds[0].name,
				time_running != time_enabled ? ", scaled":"");
		}
	}

	if (type & PERF_SAMPLE_CALLCHAIN) {
		uint64_t nr, ip;

		ret = perf_read_buffer_64(hw, &nr);
		if (ret) {
			warnx( "cannot read callchain nr");
			return -1;
		}
		sz -= sizeof(nr);

		while(nr--) {
			ret = perf_read_buffer_64(hw, &ip);
			if (ret) {
				warnx( "cannot read ip");
				return -1;
			}

			sz -= sizeof(ip);

			fprintf(fp, "\t0x%"PRIx64"\n", ip);
		}
	}

	if (type & PERF_SAMPLE_RAW) {
		ret = __perf_handle_raw(hw);
		if (ret == -1)
			return -1;
		sz -= ret;
	}

	if (type & PERF_SAMPLE_BRANCH_STACK) {
		ret = perf_display_branch_stack(hw, fp);
		sz -= ret;
	}

	if (type & PERF_SAMPLE_REGS_USER) {
		ret = perf_display_regs_user(hw, fp);
		sz -= ret;
	}

	if (type & PERF_SAMPLE_STACK_USER) {
		ret = perf_display_stack_user(hw, fp);
		sz -= ret;
	}

	if (type & PERF_SAMPLE_WEIGHT) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read weight");
			return -1;
		}
		fprintf(fp, "WEIGHT:%'"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_DATA_SRC) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read data src");
			return -1;
		}
		fprintf(fp, "DATA_SRC:%'"PRIu64" ", val64);
		sz -= sizeof(val64);
	}
	if (type & PERF_SAMPLE_TRANSACTION) {
		ret = perf_read_buffer_64(hw, &val64);
		if (ret) {
			warnx( "cannot read txn");
			return -1;
		}
		fprintf(fp, "TXN:%'"PRIu64" ", val64);
		sz -= sizeof(val64);
	}

	if (type & PERF_SAMPLE_REGS_INTR) {
		ret = perf_display_regs_intr(hw, fp);
		sz -= ret;
	}

	/*
	 * if we have some data left, it is because there is more
	 * than what we know about. In fact, it is more complicated
	 * because we may have the right size but wrong layout. But
	 * that's the best we can do.
	 */
	if (sz) {
		warnx("did not correctly parse sample leftover=%zu", sz);
		perf_skip_buffer(hw, sz);
	}

	fputc('\n',fp);
	return 0;
}

uint64_t
display_lost(perf_event_desc_t *hw, perf_event_desc_t *fds, int num_fds, FILE *fp)
{
	struct { uint64_t id, lost; } lost;
	const char *str;
	int e, ret;

	ret = perf_read_buffer(hw, &lost, sizeof(lost));
	if (ret) {
		warnx("cannot read lost info");
		return 0;
	}

	e = perf_id2event(fds, num_fds, lost.id);
	if (e == -1)
		str = "unknown lost event";
	else
		str = fds[e].name;

	fprintf(fp, "<<<LOST %"PRIu64" SAMPLES FOR EVENT %s>>>\n",
		lost.lost,
		str);

	return lost.lost;
}

void
display_exit(perf_event_desc_t *hw, FILE *fp)
{
	struct { pid_t pid, ppid, tid, ptid; } grp;
	int ret;

	ret = perf_read_buffer(hw, &grp, sizeof(grp));
	if (ret) {
		warnx("cannot read exit info");
		return;
	}

	fprintf(fp,"[%d] exited\n", grp.pid);
}

void
display_freq(int mode, perf_event_desc_t *hw, FILE *fp)
{
	struct { uint64_t time, id, stream_id; } thr;
	int ret;

	ret = perf_read_buffer(hw, &thr, sizeof(thr));
	if (ret) {
		warnx("cannot read throttling info");
		return;
	}

	fprintf(fp, "%s value=%"PRIu64" event ID=%"PRIu64"\n",
		mode ? "Throttled" : "Unthrottled",
		thr.id,
		thr.stream_id);
}
