[linux-block.git] / block / blk-mq-cpumap.c

// SPDX-License-Identifier: GPL-2.0
/*
 * CPU <-> hardware queue mapping helpers
 *
 * Copyright (C) 2013-2014 Jens Axboe
 */
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/group_cpus.h>

#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"

void blk_mq_map_queues(struct blk_mq_queue_map *qmap)
{
	const struct cpumask *masks;
	unsigned int queue, cpu;

	masks = group_cpus_evenly(qmap->nr_queues);
	if (!masks) {
		for_each_possible_cpu(cpu)
			qmap->mq_map[cpu] = qmap->queue_offset;
		return;
	}

	for (queue = 0; queue < qmap->nr_queues; queue++) {
		for_each_cpu(cpu, &masks[queue])
			qmap->mq_map[cpu] = qmap->queue_offset + queue;
	}
	kfree(masks);
}
EXPORT_SYMBOL_GPL(blk_mq_map_queues);

/**
 * blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
 * @qmap: CPU to hardware queue map.
 * @index: hardware queue index.
 *
 * We have no quick way of doing reverse lookups. This is only used at
 * queue init time, so runtime isn't important.
 */
int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
{
	int i;

	for_each_possible_cpu(i) {
		if (index == qmap->mq_map[i])
			return cpu_to_node(i);
	}

	return NUMA_NO_NODE;
}
Commit	Line	Data
3dcf60bc	1	// SPDX-License-Identifier: GPL-2.0
75bb4625 JA	2	/*
	3	* CPU <-> hardware queue mapping helpers
	4	*
	5	* Copyright (C) 2013-2014 Jens Axboe
	6	*/
320ae51f JA	7	#include <linux/kernel.h>
	8	#include <linux/threads.h>
	9	#include <linux/module.h>
	10	#include <linux/mm.h>
	11	#include <linux/smp.h>
	12	#include <linux/cpu.h>
6a6dcae8	13	#include <linux/group_cpus.h>
320ae51f JA	14
	15	#include <linux/blk-mq.h>
	16	#include "blk.h"
	17	#include "blk-mq.h"
	18
a4e1d0b7	19	void blk_mq_map_queues(struct blk_mq_queue_map *qmap)
320ae51f	20	{
6a6dcae8 ML	21	const struct cpumask *masks;
	22	unsigned int queue, cpu;
	23
	24	masks = group_cpus_evenly(qmap->nr_queues);
	25	if (!masks) {
	26	for_each_possible_cpu(cpu)
	27	qmap->mq_map[cpu] = qmap->queue_offset;
	28	return;
556f36e9	29	}
320ae51f	30
6a6dcae8 ML	31	for (queue = 0; queue < qmap->nr_queues; queue++) {
	32	for_each_cpu(cpu, &masks[queue])
	33	qmap->mq_map[cpu] = qmap->queue_offset + queue;
320ae51f	34	}
6a6dcae8	35	kfree(masks);
320ae51f	36	}
9e5a7e22	37	EXPORT_SYMBOL_GPL(blk_mq_map_queues);
320ae51f	38
cd669f88 BVA	39	/**
	40	* blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
	41	* @qmap: CPU to hardware queue map.
	42	* @index: hardware queue index.
	43	*
f14bbe77 JA	44	* We have no quick way of doing reverse lookups. This is only used at
	45	* queue init time, so runtime isn't important.
	46	*/
ed76e329	47	int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
f14bbe77 JA	48	{
	49	int i;
	50
	51	for_each_possible_cpu(i) {
ed76e329	52	if (index == qmap->mq_map[i])
576e85c5	53	return cpu_to_node(i);
f14bbe77 JA	54	}
	55
	56	return NUMA_NO_NODE;
	57	}