// SPDX-License-Identifier: GPL-2.0
/*
 * perf iostat
 *
 * Copyright (C) 2020, Intel Corporation
 *
 * Authors: Alexander Antonov <alexander.antonov@linux.intel.com>
 */

#include <api/fs/fs.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/zalloc.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <regex.h>
#include "util/cpumap.h"
#include "util/debug.h"
#include "util/iostat.h"
#include "util/counts.h"
#include "path.h"

#ifndef MAX_PATH
#define MAX_PATH 1024
#endif

#define UNCORE_IIO_PMU_PATH	"bus/event_source/devices/uncore_iio_%d"
#define SYSFS_UNCORE_PMU_PATH	"%s/"UNCORE_IIO_PMU_PATH
#define PLATFORM_MAPPING_PATH	UNCORE_IIO_PMU_PATH"/die%d"

/*
 * Each metric requiries one IIO event which increments at every 4B transfer
 * in corresponding direction. The formulas to compute metrics are generic:
 *     #EventCount * 4B / (1024 * 1024)
 */
static const char * const iostat_metrics[] = {
	"Inbound Read(MB)",
	"Inbound Write(MB)",
	"Outbound Read(MB)",
	"Outbound Write(MB)",
};

static inline int iostat_metrics_count(void)
{
	return sizeof(iostat_metrics) / sizeof(char *);
}

static const char *iostat_metric_by_idx(int idx)
{
	return *(iostat_metrics + idx % iostat_metrics_count());
}

struct iio_root_port {
	u32 domain;
	u8 bus;
	u8 die;
	u8 pmu_idx;
	int idx;
};

struct iio_root_ports_list {
	struct iio_root_port **rps;
	int nr_entries;
};

static struct iio_root_ports_list *root_ports;

static void iio_root_port_show(FILE *output,
			       const struct iio_root_port * const rp)
{
	if (output && rp)
		fprintf(output, "S%d-uncore_iio_%d<%04x:%02x>\n",
			rp->die, rp->pmu_idx, rp->domain, rp->bus);
}

static struct iio_root_port *iio_root_port_new(u32 domain, u8 bus,
					       u8 die, u8 pmu_idx)
{
	struct iio_root_port *p = calloc(1, sizeof(*p));

	if (p) {
		p->domain = domain;
		p->bus = bus;
		p->die = die;
		p->pmu_idx = pmu_idx;
	}
	return p;
}

static void iio_root_ports_list_free(struct iio_root_ports_list *list)
{
	int idx;

	if (list) {
		for (idx = 0; idx < list->nr_entries; idx++)
			zfree(&list->rps[idx]);
		zfree(&list->rps);
		free(list);
	}
}

static struct iio_root_port *iio_root_port_find_by_notation(
	const struct iio_root_ports_list * const list, u32 domain, u8 bus)
{
	int idx;
	struct iio_root_port *rp;

	if (list) {
		for (idx = 0; idx < list->nr_entries; idx++) {
			rp = list->rps[idx];
			if (rp && rp->domain == domain && rp->bus == bus)
				return rp;
		}
	}
	return NULL;
}

static int iio_root_ports_list_insert(struct iio_root_ports_list *list,
				      struct iio_root_port * const rp)
{
	struct iio_root_port **tmp_buf;

	if (list && rp) {
		rp->idx = list->nr_entries++;
		tmp_buf = realloc(list->rps,
				  list->nr_entries * sizeof(*list->rps));
		if (!tmp_buf) {
			pr_err("Failed to realloc memory\n");
			return -ENOMEM;
		}
		tmp_buf[rp->idx] = rp;
		list->rps = tmp_buf;
	}
	return 0;
}

static int iio_mapping(u8 pmu_idx, struct iio_root_ports_list * const list)
{
	char *buf;
	char path[MAX_PATH];
	u32 domain;
	u8 bus;
	struct iio_root_port *rp;
	size_t size;
	int ret;

	for (int die = 0; die < cpu__max_node(); die++) {
		scnprintf(path, MAX_PATH, PLATFORM_MAPPING_PATH, pmu_idx, die);
		if (sysfs__read_str(path, &buf, &size) < 0) {
			if (pmu_idx)
				goto out;
			pr_err("Mode iostat is not supported\n");
			return -1;
		}
		ret = sscanf(buf, "%04x:%02hhx", &domain, &bus);
		free(buf);
		if (ret != 2) {
			pr_err("Invalid mapping data: iio_%d; die%d\n",
			       pmu_idx, die);
			return -1;
		}
		rp = iio_root_port_new(domain, bus, die, pmu_idx);
		if (!rp || iio_root_ports_list_insert(list, rp)) {
			free(rp);
			return -ENOMEM;
		}
	}
out:
	return 0;
}

static u8 iio_pmu_count(void)
{
	u8 pmu_idx = 0;
	char path[MAX_PATH];
	const char *sysfs = sysfs__mountpoint();

	if (sysfs) {
		for (;; pmu_idx++) {
			snprintf(path, sizeof(path), SYSFS_UNCORE_PMU_PATH,
				 sysfs, pmu_idx);
			if (access(path, F_OK) != 0)
				break;
		}
	}
	return pmu_idx;
}

static int iio_root_ports_scan(struct iio_root_ports_list **list)
{
	int ret = -ENOMEM;
	struct iio_root_ports_list *tmp_list;
	u8 pmu_count = iio_pmu_count();

	if (!pmu_count) {
		pr_err("Unsupported uncore pmu configuration\n");
		return -1;
	}

	tmp_list = calloc(1, sizeof(*tmp_list));
	if (!tmp_list)
		goto err;

	for (u8 pmu_idx = 0; pmu_idx < pmu_count; pmu_idx++) {
		ret = iio_mapping(pmu_idx, tmp_list);
		if (ret)
			break;
	}
err:
	if (!ret)
		*list = tmp_list;
	else
		iio_root_ports_list_free(tmp_list);

	return ret;
}

static int iio_root_port_parse_str(u32 *domain, u8 *bus, char *str)
{
	int ret;
	regex_t regex;
	/*
	 * Expected format domain:bus:
	 * Valid domain range [0:ffff]
	 * Valid bus range [0:ff]
	 * Example: 0000:af, 0:3d, 01:7
	 */
	regcomp(&regex, "^([a-f0-9A-F]{1,}):([a-f0-9A-F]{1,2})", REG_EXTENDED);
	ret = regexec(&regex, str, 0, NULL, 0);
	if (ret || sscanf(str, "%08x:%02hhx", domain, bus) != 2)
		pr_warning("Unrecognized root port format: %s\n"
			   "Please use the following format:\n"
			   "\t [domain]:[bus]\n"
			   "\t for example: 0000:3d\n", str);

	regfree(&regex);
	return ret;
}

static int iio_root_ports_list_filter(struct iio_root_ports_list **list,
				      const char *filter)
{
	char *tok, *tmp, *filter_copy = NULL;
	struct iio_root_port *rp;
	u32 domain;
	u8 bus;
	int ret = -ENOMEM;
	struct iio_root_ports_list *tmp_list = calloc(1, sizeof(*tmp_list));

	if (!tmp_list)
		goto err;

	filter_copy = strdup(filter);
	if (!filter_copy)
		goto err;

	for (tok = strtok_r(filter_copy, ",", &tmp); tok;
	     tok = strtok_r(NULL, ",", &tmp)) {
		if (!iio_root_port_parse_str(&domain, &bus, tok)) {
			rp = iio_root_port_find_by_notation(*list, domain, bus);
			if (rp) {
				(*list)->rps[rp->idx] = NULL;
				ret = iio_root_ports_list_insert(tmp_list, rp);
				if (ret) {
					free(rp);
					goto err;
				}
			} else if (!iio_root_port_find_by_notation(tmp_list,
								   domain, bus))
				pr_warning("Root port %04x:%02x were not found\n",
					   domain, bus);
		}
	}

	if (tmp_list->nr_entries == 0) {
		pr_err("Requested root ports were not found\n");
		ret = -EINVAL;
	}
err:
	iio_root_ports_list_free(*list);
	if (ret)
		iio_root_ports_list_free(tmp_list);
	else
		*list = tmp_list;

	free(filter_copy);
	return ret;
}

static int iostat_event_group(struct evlist *evl,
			      struct iio_root_ports_list *list)
{
	int ret;
	int idx;
	const char *iostat_cmd_template =
	"{uncore_iio_%x/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/,\
	  uncore_iio_%x/event=0x83,umask=0x01,ch_mask=0xF,fc_mask=0x07/,\
	  uncore_iio_%x/event=0xc0,umask=0x04,ch_mask=0xF,fc_mask=0x07/,\
	  uncore_iio_%x/event=0xc0,umask=0x01,ch_mask=0xF,fc_mask=0x07/}";
	const int len_template = strlen(iostat_cmd_template) + 1;
	struct evsel *evsel = NULL;
	int metrics_count = iostat_metrics_count();
	char *iostat_cmd = calloc(len_template, 1);

	if (!iostat_cmd)
		return -ENOMEM;

	for (idx = 0; idx < list->nr_entries; idx++) {
		sprintf(iostat_cmd, iostat_cmd_template,
			list->rps[idx]->pmu_idx, list->rps[idx]->pmu_idx,
			list->rps[idx]->pmu_idx, list->rps[idx]->pmu_idx);
		ret = parse_event(evl, iostat_cmd);
		if (ret)
			goto err;
	}

	evlist__for_each_entry(evl, evsel) {
		evsel->priv = list->rps[evsel->core.idx / metrics_count];
	}
	list->nr_entries = 0;
err:
	iio_root_ports_list_free(list);
	free(iostat_cmd);
	return ret;
}

int iostat_prepare(struct evlist *evlist, struct perf_stat_config *config)
{
	if (evlist->core.nr_entries > 0) {
		pr_warning("The -e and -M options are not supported."
			   "All chosen events/metrics will be dropped\n");
		evlist__delete(evlist);
		evlist = evlist__new();
		if (!evlist)
			return -ENOMEM;
	}

	config->metric_only = true;
	config->aggr_mode = AGGR_GLOBAL;

	return iostat_event_group(evlist, root_ports);
}

int iostat_parse(const struct option *opt, const char *str,
		 int unset __maybe_unused)
{
	int ret;
	struct perf_stat_config *config = (struct perf_stat_config *)opt->data;

	ret = iio_root_ports_scan(&root_ports);
	if (!ret) {
		config->iostat_run = true;
		if (!str)
			iostat_mode = IOSTAT_RUN;
		else if (!strcmp(str, "list"))
			iostat_mode = IOSTAT_LIST;
		else {
			iostat_mode = IOSTAT_RUN;
			ret = iio_root_ports_list_filter(&root_ports, str);
		}
	}
	return ret;
}

void iostat_list(struct evlist *evlist, struct perf_stat_config *config)
{
	struct evsel *evsel;
	struct iio_root_port *rp = NULL;

	evlist__for_each_entry(evlist, evsel) {
		if (rp != evsel->priv) {
			rp = evsel->priv;
			iio_root_port_show(config->output, rp);
		}
	}
}

void iostat_release(struct evlist *evlist)
{
	struct evsel *evsel;
	struct iio_root_port *rp = NULL;

	evlist__for_each_entry(evlist, evsel) {
		if (rp != evsel->priv) {
			rp = evsel->priv;
			zfree(&evsel->priv);
		}
	}
}

void iostat_prefix(struct evlist *evlist,
		   struct perf_stat_config *config,
		   char *prefix, struct timespec *ts)
{
	struct iio_root_port *rp = evlist->selected->priv;

	if (rp) {
		/*
		 * TODO: This is the incorrect format in JSON mode.
		 *       See prepare_timestamp()
		 */
		if (ts)
			sprintf(prefix, "%6lu.%09lu%s%04x:%02x%s",
				ts->tv_sec, ts->tv_nsec,
				config->csv_sep, rp->domain, rp->bus,
				config->csv_sep);
		else
			sprintf(prefix, "%04x:%02x%s", rp->domain, rp->bus,
				config->csv_sep);
	}
}

void iostat_print_header_prefix(struct perf_stat_config *config)
{
	if (config->csv_output)
		fputs("port,", config->output);
	else if (config->interval)
		fprintf(config->output, "#          time    port         ");
	else
		fprintf(config->output, "   port         ");
}

void iostat_print_metric(struct perf_stat_config *config, struct evsel *evsel,
			 struct perf_stat_output_ctx *out)
{
	double iostat_value = 0;
	u64 prev_count_val = 0;
	const char *iostat_metric = iostat_metric_by_idx(evsel->core.idx);
	u8 die = ((struct iio_root_port *)evsel->priv)->die;
	struct perf_counts_values *count = perf_counts(evsel->counts, die, 0);

	if (count && count->run && count->ena) {
		if (evsel->prev_raw_counts && !out->force_header) {
			struct perf_counts_values *prev_count =
				perf_counts(evsel->prev_raw_counts, die, 0);

			prev_count_val = prev_count->val;
			prev_count->val = count->val;
		}
		iostat_value = (count->val - prev_count_val) /
			       ((double) count->run / count->ena);
	}
	out->print_metric(config, out->ctx, METRIC_THRESHOLD_UNKNOWN, "%8.0f", iostat_metric,
			  iostat_value / (256 * 1024));
}

void iostat_print_counters(struct evlist *evlist,
			   struct perf_stat_config *config, struct timespec *ts,
			   char *prefix, iostat_print_counter_t print_cnt_cb, void *arg)
{
	void *perf_device = NULL;
	struct evsel *counter = evlist__first(evlist);

	evlist__set_selected(evlist, counter);
	iostat_prefix(evlist, config, prefix, ts);
	fprintf(config->output, "%s", prefix);
	evlist__for_each_entry(evlist, counter) {
		perf_device = evlist->selected->priv;
		if (perf_device && perf_device != counter->priv) {
			evlist__set_selected(evlist, counter);
			iostat_prefix(evlist, config, prefix, ts);
			fprintf(config->output, "\n%s", prefix);
		}
		print_cnt_cb(config, counter, arg);
	}
	fputc('\n', config->output);
}
