pinctrl: at91-pio4: add missing of_node_put
[linux-2.6-block.git] / block / blk-mq-pci.c
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1/*
2 * Copyright (c) 2016 Christoph Hellwig.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 */
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13#include <linux/kobject.h>
14#include <linux/blkdev.h>
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15#include <linux/blk-mq.h>
16#include <linux/blk-mq-pci.h>
17#include <linux/pci.h>
18#include <linux/module.h>
19
20/**
21 * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
22 * @set: tagset to provide the mapping for
23 * @pdev: PCI device associated with @set.
f23f5bec 24 * @offset: Offset to use for the pci irq vector
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25 *
26 * This function assumes the PCI device @pdev has at least as many available
018c259b 27 * interrupt vectors as @set has queues. It will then query the vector
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28 * corresponding to each queue for it's affinity mask and built queue mapping
29 * that maps a queue to the CPUs that have irq affinity for the corresponding
30 * vector.
31 */
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32int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
33 int offset)
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34{
35 const struct cpumask *mask;
36 unsigned int queue, cpu;
37
38 for (queue = 0; queue < set->nr_hw_queues; queue++) {
f23f5bec 39 mask = pci_irq_get_affinity(pdev, queue + offset);
973c4e37 40 if (!mask)
c0053903 41 goto fallback;
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42
43 for_each_cpu(cpu, mask)
44 set->mq_map[cpu] = queue;
45 }
46
47 return 0;
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48
49fallback:
50 WARN_ON_ONCE(set->nr_hw_queues > 1);
51 for_each_possible_cpu(cpu)
52 set->mq_map[cpu] = 0;
53 return 0;
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54}
55EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);