1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Copyright (c) 2016 Christoph Hellwig. 4*4882a593Smuzhiyun */ 5*4882a593Smuzhiyun #include <linux/kobject.h> 6*4882a593Smuzhiyun #include <linux/blkdev.h> 7*4882a593Smuzhiyun #include <linux/blk-mq.h> 8*4882a593Smuzhiyun #include <linux/blk-mq-pci.h> 9*4882a593Smuzhiyun #include <linux/pci.h> 10*4882a593Smuzhiyun #include <linux/module.h> 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun #include "blk-mq.h" 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun /** 15*4882a593Smuzhiyun * blk_mq_pci_map_queues - provide a default queue mapping for PCI device 16*4882a593Smuzhiyun * @qmap: CPU to hardware queue map. 17*4882a593Smuzhiyun * @pdev: PCI device associated with @set. 18*4882a593Smuzhiyun * @offset: Offset to use for the pci irq vector 19*4882a593Smuzhiyun * 20*4882a593Smuzhiyun * This function assumes the PCI device @pdev has at least as many available 21*4882a593Smuzhiyun * interrupt vectors as @set has queues. It will then query the vector 22*4882a593Smuzhiyun * corresponding to each queue for it's affinity mask and built queue mapping 23*4882a593Smuzhiyun * that maps a queue to the CPUs that have irq affinity for the corresponding 24*4882a593Smuzhiyun * vector. 25*4882a593Smuzhiyun */ blk_mq_pci_map_queues(struct blk_mq_queue_map * qmap,struct pci_dev * pdev,int offset)26*4882a593Smuzhiyunint blk_mq_pci_map_queues(struct blk_mq_queue_map *qmap, struct pci_dev *pdev, 27*4882a593Smuzhiyun int offset) 28*4882a593Smuzhiyun { 29*4882a593Smuzhiyun const struct cpumask *mask; 30*4882a593Smuzhiyun unsigned int queue, cpu; 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun for (queue = 0; queue < qmap->nr_queues; queue++) { 33*4882a593Smuzhiyun mask = pci_irq_get_affinity(pdev, queue + offset); 34*4882a593Smuzhiyun if (!mask) 35*4882a593Smuzhiyun goto fallback; 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun for_each_cpu(cpu, mask) 38*4882a593Smuzhiyun qmap->mq_map[cpu] = qmap->queue_offset + queue; 39*4882a593Smuzhiyun } 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun return 0; 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun fallback: 44*4882a593Smuzhiyun WARN_ON_ONCE(qmap->nr_queues > 1); 45*4882a593Smuzhiyun blk_mq_clear_mq_map(qmap); 46*4882a593Smuzhiyun return 0; 47*4882a593Smuzhiyun } 48*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues); 49