/* 

 * Copyright (C) 2006, Intel Corporation

 * Copyright (C) 2012, Neil Horman <nhorman@tuxdriver.com> 

 * 

 * This file is part of irqbalance

 *

 * This program file is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; version 2 of the License.

 * 

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program in a file named COPYING; if not, write to the 

 * Free Software Foundation, Inc., 

 * 51 Franklin Street, Fifth Floor, 

 * Boston, MA 02110-1301 USA

 */

/* 

 * This file contains the code to communicate a selected distribution / mapping

 * of interrupts to the kernel.

 */

#include "config.h"

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <stdint.h>

#include "irqbalance.h"

static int check_affinity(struct irq_info *info, cpumask_t applied_mask)

{

	cpumask_t current_mask;

	char buf[PATH_MAX];

	char *line = NULL;

	size_t size = 0;

	FILE *file;

	sprintf(buf, "/proc/irq/%i/smp_affinity", info->irq);

	file = fopen(buf, "r");

	if (!file)

		return 1;

	if (getline(&line, &size, file)==0) {

		free(line);

		fclose(file);

		return 1;

	}

	cpumask_parse_user(line, strlen(line), current_mask);

	fclose(file);

	free(line);

	return cpus_equal(applied_mask, current_mask);

}

static void activate_mapping(struct irq_info *info, void *data __attribute__((unused)))

{

	char buf[PATH_MAX];

	FILE *file;

	cpumask_t applied_mask;

	int valid_mask = 0;

	/*

 	 * only activate mappings for irqs that have moved

 	 */

	if (!info->moved)

		return;

	if (info->assigned_obj) {

		applied_mask = info->assigned_obj->mask;

		valid_mask = 1;

	}

	/*

 	 * Don't activate anything for which we have an invalid mask 

 	 */

	if (!valid_mask || check_affinity(info, applied_mask))

		return;

	if (!info->assigned_obj)

		return;

	sprintf(buf, "/proc/irq/%i/smp_affinity", info->irq);

	file = fopen(buf, "w");

	if (!file)

		return;

	cpumask_scnprintf(buf, PATH_MAX, applied_mask);

	fprintf(file, "%s", buf);

	fclose(file);

	info->moved = 0; /*migration is done*/

}

void activate_mappings(void)

{

	for_each_irq(NULL, activate_mapping, NULL);

}