Line data    Source code

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