| Christoph Hellwig | 973c4e3 | 2016-09-14 16:18:56 +0200 | [diff] [blame^] | 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 | */ |
| 13 | #include <linux/blk-mq.h> |
| 14 | #include <linux/blk-mq-pci.h> |
| 15 | #include <linux/pci.h> |
| 16 | #include <linux/module.h> |
| 17 | |
| 18 | /** |
| 19 | * blk_mq_pci_map_queues - provide a default queue mapping for PCI device |
| 20 | * @set: tagset to provide the mapping for |
| 21 | * @pdev: PCI device associated with @set. |
| 22 | * |
| 23 | * This function assumes the PCI device @pdev has at least as many available |
| 24 | * interrupt vetors as @set has queues. It will then queuery the vector |
| 25 | * corresponding to each queue for it's affinity mask and built queue mapping |
| 26 | * that maps a queue to the CPUs that have irq affinity for the corresponding |
| 27 | * vector. |
| 28 | */ |
| 29 | int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev) |
| 30 | { |
| 31 | const struct cpumask *mask; |
| 32 | unsigned int queue, cpu; |
| 33 | |
| 34 | for (queue = 0; queue < set->nr_hw_queues; queue++) { |
| 35 | mask = pci_irq_get_affinity(pdev, queue); |
| 36 | if (!mask) |
| 37 | return -EINVAL; |
| 38 | |
| 39 | for_each_cpu(cpu, mask) |
| 40 | set->mq_map[cpu] = queue; |
| 41 | } |
| 42 | |
| 43 | return 0; |
| 44 | } |
| 45 | EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues); |