#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <api/fs/fs.h>
#include "mem-events.h"
#include "debug.h"
#include "symbol.h"

#define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }

struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
	E("ldlat-loads",	"cpu/mem-loads,ldlat=30/P",	"mem-loads"),
	E("ldlat-stores",	"cpu/mem-stores/P",		"mem-stores"),
};
#undef E

#undef E

char *perf_mem_events__name(int i)
{
	return (char *)perf_mem_events[i].name;
}

int perf_mem_events__parse(const char *str)
{
	char *tok, *saveptr = NULL;
	bool found = false;
	char *buf;
	int j;

	/* We need buffer that we know we can write to. */
	buf = malloc(strlen(str) + 1);
	if (!buf)
		return -ENOMEM;

	strcpy(buf, str);

	tok = strtok_r((char *)buf, ",", &saveptr);

	while (tok) {
		for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
			struct perf_mem_event *e = &perf_mem_events[j];

			if (strstr(e->tag, tok))
				e->record = found = true;
		}

		tok = strtok_r(NULL, ",", &saveptr);
	}

	free(buf);

	if (found)
		return 0;

	pr_err("failed: event '%s' not found, use '-e list' to get list of available events\n", str);
	return -1;
}

int perf_mem_events__init(void)
{
	const char *mnt = sysfs__mount();
	bool found = false;
	int j;

	if (!mnt)
		return -ENOENT;

	for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
		char path[PATH_MAX];
		struct perf_mem_event *e = &perf_mem_events[j];
		struct stat st;

		scnprintf(path, PATH_MAX, "%s/devices/cpu/events/%s",
			  mnt, e->sysfs_name);

		if (!stat(path, &st))
			e->supported = found = true;
	}

	return found ? 0 : -ENOENT;
}

static const char * const tlb_access[] = {
	"N/A",
	"HIT",
	"MISS",
	"L1",
	"L2",
	"Walker",
	"Fault",
};

void perf_mem__tlb_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
	size_t l = 0, i;
	u64 m = PERF_MEM_TLB_NA;
	u64 hit, miss;

	sz -= 1; /* -1 for null termination */
	out[0] = '\0';

	if (mem_info)
		m = mem_info->data_src.mem_dtlb;

	hit = m & PERF_MEM_TLB_HIT;
	miss = m & PERF_MEM_TLB_MISS;

	/* already taken care of */
	m &= ~(PERF_MEM_TLB_HIT|PERF_MEM_TLB_MISS);

	for (i = 0; m && i < ARRAY_SIZE(tlb_access); i++, m >>= 1) {
		if (!(m & 0x1))
			continue;
		if (l) {
			strcat(out, " or ");
			l += 4;
		}
		strncat(out, tlb_access[i], sz - l);
		l += strlen(tlb_access[i]);
	}
	if (*out == '\0')
		strcpy(out, "N/A");
	if (hit)
		strncat(out, " hit", sz - l);
	if (miss)
		strncat(out, " miss", sz - l);
}

static const char * const mem_lvl[] = {
	"N/A",
	"HIT",
	"MISS",
	"L1",
	"LFB",
	"L2",
	"L3",
	"Local RAM",
	"Remote RAM (1 hop)",
	"Remote RAM (2 hops)",
	"Remote Cache (1 hop)",
	"Remote Cache (2 hops)",
	"I/O",
	"Uncached",
};

void perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
	size_t i, l = 0;
	u64 m =  PERF_MEM_LVL_NA;
	u64 hit, miss;

	if (mem_info)
		m  = mem_info->data_src.mem_lvl;

	sz -= 1; /* -1 for null termination */
	out[0] = '\0';

	hit = m & PERF_MEM_LVL_HIT;
	miss = m & PERF_MEM_LVL_MISS;

	/* already taken care of */
	m &= ~(PERF_MEM_LVL_HIT|PERF_MEM_LVL_MISS);

	for (i = 0; m && i < ARRAY_SIZE(mem_lvl); i++, m >>= 1) {
		if (!(m & 0x1))
			continue;
		if (l) {
			strcat(out, " or ");
			l += 4;
		}
		strncat(out, mem_lvl[i], sz - l);
		l += strlen(mem_lvl[i]);
	}
	if (*out == '\0')
		strcpy(out, "N/A");
	if (hit)
		strncat(out, " hit", sz - l);
	if (miss)
		strncat(out, " miss", sz - l);
}