1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * CPU <-> hardware queue mapping helpers 4 * 5 * Copyright (C) 2013-2014 Jens Axboe 6 */ 7 #include <linux/kernel.h> 8 #include <linux/threads.h> 9 #include <linux/module.h> 10 #include <linux/mm.h> 11 #include <linux/smp.h> 12 #include <linux/cpu.h> 13 #include <linux/group_cpus.h> 14 15 #include "blk.h" 16 #include "blk-mq.h" 17 blk_mq_map_queues(struct blk_mq_queue_map * qmap)18void blk_mq_map_queues(struct blk_mq_queue_map *qmap) 19 { 20 const struct cpumask *masks; 21 unsigned int queue, cpu; 22 23 masks = group_cpus_evenly(qmap->nr_queues); 24 if (!masks) { 25 for_each_possible_cpu(cpu) 26 qmap->mq_map[cpu] = qmap->queue_offset; 27 return; 28 } 29 30 for (queue = 0; queue < qmap->nr_queues; queue++) { 31 for_each_cpu(cpu, &masks[queue]) 32 qmap->mq_map[cpu] = qmap->queue_offset + queue; 33 } 34 kfree(masks); 35 } 36 EXPORT_SYMBOL_GPL(blk_mq_map_queues); 37 38 /** 39 * blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index 40 * @qmap: CPU to hardware queue map. 41 * @index: hardware queue index. 42 * 43 * We have no quick way of doing reverse lookups. This is only used at 44 * queue init time, so runtime isn't important. 45 */ blk_mq_hw_queue_to_node(struct blk_mq_queue_map * qmap,unsigned int index)46int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index) 47 { 48 int i; 49 50 for_each_possible_cpu(i) { 51 if (index == qmap->mq_map[i]) 52 return cpu_to_node(i); 53 } 54 55 return NUMA_NO_NODE; 56 } 57