/*
 * Copyright 2022 Advanced Micro Devices, Inc.
 *
 * 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 * Authors: Tom St Denis <tom.stdenis@amd.com>
 *
 */
#include "umr.h"
#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>

/* dir struct for add_ip_intances
        ├── 1 <= hw_id use name aliases instead
        │   └── 0 <= instance of this IP block
        │       ├── base_addr <= list of segments in hex
        │       ├── hw_id
        │       ├── major <= dec
        │       ├── minor <= dec
        │       ├── num_base_addresses
        │       ├── num_instance
        │       └── revision <= dec
*/
static void add_ip_instances(struct umr_discovery_table_entry **det, int die_num, int *nblocks, char *diepath, char *ipname)
{
	DIR *ipdir;
	char linebuf[512], fname[1024], databuf[256];
	struct dirent *de;
	int x;
	FILE *f;

	snprintf(linebuf, (sizeof linebuf) - 1, "%s/%s", diepath, ipname);
	ipdir = opendir(linebuf);
	if (!ipdir)
		return;
	while ((de = readdir(ipdir))) {
		if (isdigit(de->d_name[0])) {
			snprintf(linebuf, (sizeof linebuf) - 1, "%s/%s/%s", diepath, ipname, de->d_name); // path to instance of ip block on given die
			(*det)->die = die_num;
			// base_addr list
			snprintf(fname, (sizeof fname) - 1, "%s/base_addr", linebuf);
			f = fopen(fname, "r");
				x = 0;
				while (fgets(databuf, sizeof databuf, f)) {
					if (sscanf(databuf, "%"SCNx64, &(*det)->segments[x]) != 1)
						break;
					++x;
				}
			fclose(f);
			// major
			snprintf(fname, (sizeof fname) - 1, "%s/major", linebuf);
			f = fopen(fname, "r");
				fgets(databuf, sizeof databuf, f);
				sscanf(databuf, "%d", &(*det)->maj);
			fclose(f);
			// minor
			snprintf(fname, (sizeof fname) - 1, "%s/minor", linebuf);
			f = fopen(fname, "r");
				fgets(databuf, sizeof databuf, f);
				sscanf(databuf, "%d", &(*det)->min);
			fclose(f);
			// revision
			snprintf(fname, (sizeof fname) - 1, "%s/revision", linebuf);
			f = fopen(fname, "r");
				fgets(databuf, sizeof databuf, f);
				sscanf(databuf, "%d", &(*det)->rev);
			fclose(f);
			// instance
			snprintf(fname, (sizeof fname) - 1, "%s/num_instance", linebuf);
			f = fopen(fname, "r");
				fgets(databuf, sizeof databuf, f);
				sscanf(databuf, "%d", &(*det)->instance);
			fclose(f);
			// convert name to lowercase
			strcpy((*det)->ipname, ipname);
			for (x = 0; (*det)->ipname[x]; x++)
				(*det)->ipname[x] = tolower((*det)->ipname[x]);
			// add next
			(*det)->next = calloc(1, sizeof **det);
			if (!(*det)->next) {
				closedir(ipdir);
				return;
			}
			*det = (*det)->next;
			++(*nblocks);
		}
	}
	closedir(ipdir);
}

/* Dir structure
 *
.
└── die
    └── 0
        ├── 1 <= hw_id use name aliases instead
        │   └── 0 <= instance of this IP block
        │       ├── base_addr <= list of segments in hex
        │       ├── hw_id
        │       ├── major <= dec
        │       ├── minor <= dec
        │       ├── num_base_addresses
        │       ├── num_instance
        │       └── revision <= dec
*/
struct umr_discovery_table_entry *umr_parse_ip_discovery(int instance, int *nblocks, umr_err_output errout)
{
	DIR *top = NULL, *die = NULL;
	char linebuf[512];
	struct umr_discovery_table_entry *pdet, *det;
	struct dirent *de;
	int die_num;

	snprintf(linebuf, (sizeof linebuf) - 1, "/sys/class/drm/card%d/device/ip_discovery/die", instance);
	top = opendir(linebuf);
	if (!top) {
		return NULL;
	}

	pdet = det = calloc(1, sizeof *det);
	*nblocks = 0;
	// iterate over every die
	while ((de = readdir(top))) {
		if (strcmp(de->d_name, ".") && strcmp(de->d_name, "..")) {
			die_num = atoi(de->d_name);

			// process die directory
			snprintf(linebuf, (sizeof linebuf) - 1, "/sys/class/drm/card%d/device/ip_discovery/die/%s", instance, de->d_name);
			die = opendir(linebuf);
			if (!die) {
				errout("Cannot open IP discovery die directory\n");
				goto error;
			}
			while ((de = readdir(die))) {
				if (isalpha(de->d_name[0])) {
					add_ip_instances(&det, die_num, nblocks, linebuf, de->d_name);
				}
			}
			closedir(die);
		}
	}
	closedir(top);
	return pdet;
error:
	*nblocks = 0;
	if (top)
		closedir(top);
	if (die)
		closedir(die);
	det = pdet;
	while (det) {
		pdet = det->next;
		free(det);
		det = pdet;
	}
	return NULL;
}