From 1452e9b470c903fc4137a448e9f5767e92d68229 Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Mon, 2 Dec 2024 15:00:12 +0100 Subject: [PATCH] blk-mq: introduce blk_mq_map_hw_queues blk_mq_pci_map_queues and blk_mq_virtio_map_queues will create a CPU to hardware queue mapping based on affinity information. These two function share common code and only differ on how the affinity information is retrieved. Also, those functions are located in the block subsystem where it doesn't really fit in. They are virtio and pci subsystem specific. Thus introduce provide a generic mapping function which uses the irq_get_affinity callback from bus_type. Originally idea from Ming Lei Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Ming Lei Reviewed-by: John Garry Signed-off-by: Daniel Wagner Link: https://lore.kernel.org/r/20241202-refactor-blk-affinity-helpers-v6-4-27211e9c2cd5@kernel.org Signed-off-by: Jens Axboe --- block/blk-mq-cpumap.c | 37 +++++++++++++++++++++++++++++++++++++ include/linux/blk-mq.h | 2 ++ 2 files changed, 39 insertions(+) diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 9638b25fd5212..ad8d6a363f24a 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "blk.h" #include "blk-mq.h" @@ -54,3 +55,39 @@ int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index) return NUMA_NO_NODE; } + +/** + * blk_mq_map_hw_queues - Create CPU to hardware queue mapping + * @qmap: CPU to hardware queue map + * @dev: The device to map queues + * @offset: Queue offset to use for the device + * + * Create a CPU to hardware queue mapping in @qmap. The struct bus_type + * irq_get_affinity callback will be used to retrieve the affinity. + */ +void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap, + struct device *dev, unsigned int offset) + +{ + const struct cpumask *mask; + unsigned int queue, cpu; + + if (!dev->bus->irq_get_affinity) + goto fallback; + + for (queue = 0; queue < qmap->nr_queues; queue++) { + mask = dev->bus->irq_get_affinity(dev, queue + offset); + if (!mask) + goto fallback; + + for_each_cpu(cpu, mask) + qmap->mq_map[cpu] = qmap->queue_offset + queue; + } + + return; + +fallback: + WARN_ON_ONCE(qmap->nr_queues > 1); + blk_mq_clear_mq_map(qmap); +} +EXPORT_SYMBOL_GPL(blk_mq_map_hw_queues); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index c596e0e4cb751..769eab6247d49 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -921,6 +921,8 @@ void blk_mq_unfreeze_queue_non_owner(struct request_queue *q); void blk_freeze_queue_start_non_owner(struct request_queue *q); void blk_mq_map_queues(struct blk_mq_queue_map *qmap); +void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap, + struct device *dev, unsigned int offset); void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); void blk_mq_quiesce_queue_nowait(struct request_queue *q);