diff options
Diffstat (limited to 'block/blk-mq-pci.c')
| -rw-r--r-- | block/blk-mq-pci.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c new file mode 100644 index 000000000000..33c7bd743c63 --- /dev/null +++ b/block/blk-mq-pci.c @@ -0,0 +1,45 @@ +/* + * Copyright (c) 2016 Christoph Hellwig. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ +#include <linux/blk-mq.h> +#include <linux/blk-mq-pci.h> +#include <linux/pci.h> +#include <linux/module.h> + +/** + * blk_mq_pci_map_queues - provide a default queue mapping for PCI device + * @set: tagset to provide the mapping for + * @pdev: PCI device associated with @set. + * + * This function assumes the PCI device @pdev has at least as many available + * interrupt vetors as @set has queues. It will then queuery 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. + */ +int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev) +{ + const struct cpumask *mask; + unsigned int queue, cpu; + + for (queue = 0; queue < set->nr_hw_queues; queue++) { + mask = pci_irq_get_affinity(pdev, queue); + if (!mask) + return -EINVAL; + + for_each_cpu(cpu, mask) + set->mq_map[cpu] = queue; + } + + return 0; +} +EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues); |