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

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016 Christoph Hellwig.
 */
#include <linux/kobject.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/blk-mq-pci.h>
#include <linux/pci.h>
#include <linux/module.h>

#include "blk-mq.h"

/**
 * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
 * @qmap:	CPU to hardware queue map.
 * @pdev:	PCI device associated with @set.
 * @offset:	Offset to use for the pci irq vector
 *
 * This function assumes the PCI device @pdev has at least as many available
 * interrupt vectors as @set has queues.  It will then query the vector
 * corresponding to each queue for it's affinity mask and built queue mapping
 * that maps a queue to the CPUs that have irq affinity for the corresponding
 * vector.
 */
void blk_mq_pci_map_queues(struct blk_mq_queue_map *qmap, struct pci_dev *pdev,
			   int offset)
{
	const struct cpumask *mask;
	unsigned int queue, cpu;

	for (queue = 0; queue < qmap->nr_queues; queue++) {
		mask = pci_irq_get_affinity(pdev, queue + offset);
		if (!mask)
			goto fallback;

		for_each_cpu(cpu, mask)
			qmap->mq_map[cpu] = qmap->queue_offset + queue;
	}

	return;

fallback:
	WARN_ON_ONCE(qmap->nr_queues > 1);
	blk_mq_clear_mq_map(qmap);
}
EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (c) 2016 Christoph Hellwig.
	4	*/
	5	#include <linux/kobject.h>
	6	#include <linux/blkdev.h>
	7	#include <linux/blk-mq.h>
	8	#include <linux/blk-mq-pci.h>
	9	#include <linux/pci.h>
	10	#include <linux/module.h>
	11
	12	#include "blk-mq.h"
	13
	14	/**
	15	* blk_mq_pci_map_queues - provide a default queue mapping for PCI device
	16	* @qmap: CPU to hardware queue map.
	17	* @pdev: PCI device associated with @set.
	18	* @offset: Offset to use for the pci irq vector
	19	*
	20	* This function assumes the PCI device @pdev has at least as many available
	21	* interrupt vectors as @set has queues. It will then query the vector
	22	* corresponding to each queue for it's affinity mask and built queue mapping
	23	* that maps a queue to the CPUs that have irq affinity for the corresponding
	24	* vector.
	25	*/
	26	void blk_mq_pci_map_queues(struct blk_mq_queue_map qmap, struct pci_dev pdev,
	27	int offset)
	28	{
	29	const struct cpumask *mask;
	30	unsigned int queue, cpu;
	31
	32	for (queue = 0; queue < qmap->nr_queues; queue++) {
	33	mask = pci_irq_get_affinity(pdev, queue + offset);
	34	if (!mask)
	35	goto fallback;
	36
	37	for_each_cpu(cpu, mask)
	38	qmap->mq_map[cpu] = qmap->queue_offset + queue;
	39	}
	40
	41	return;
	42
	43	fallback:
	44	WARN_ON_ONCE(qmap->nr_queues > 1);
	45	blk_mq_clear_mq_map(qmap);
	46	}
	47	EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);