[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 "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	14
320ae51f JA	15	#include "blk.h"
	16	#include "blk-mq.h"
	17
a4e1d0b7	18	void blk_mq_map_queues(struct blk_mq_queue_map *qmap)
320ae51f	19	{
6a6dcae8 ML	20	const struct cpumask *masks;
	21	unsigned int queue, cpu;
	22
	23	masks = group_cpus_evenly(qmap->nr_queues);
	24	if (!masks) {
	25	for_each_possible_cpu(cpu)
	26	qmap->mq_map[cpu] = qmap->queue_offset;
	27	return;
556f36e9	28	}
320ae51f	29
6a6dcae8 ML	30	for (queue = 0; queue < qmap->nr_queues; queue++) {
	31	for_each_cpu(cpu, &masks[queue])
	32	qmap->mq_map[cpu] = qmap->queue_offset + queue;
320ae51f	33	}
6a6dcae8	34	kfree(masks);
320ae51f	35	}
9e5a7e22	36	EXPORT_SYMBOL_GPL(blk_mq_map_queues);
320ae51f	37
cd669f88 BVA	38	/**
	39	* blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
	40	* @qmap: CPU to hardware queue map.
	41	* @index: hardware queue index.
	42	*
f14bbe77 JA	43	* We have no quick way of doing reverse lookups. This is only used at
	44	* queue init time, so runtime isn't important.
	45	*/
ed76e329	46	int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
f14bbe77 JA	47	{
	48	int i;
	49
	50	for_each_possible_cpu(i) {
ed76e329	51	if (index == qmap->mq_map[i])
576e85c5	52	return cpu_to_node(i);
f14bbe77 JA	53	}
	54
	55	return NUMA_NO_NODE;
	56	}