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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-02 13:53:13 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-02 13:53:13 -0800 |
commit | 54d7989f476ca57fc3c5cc71524c480ccb74c481 (patch) | |
tree | 62a6b61edac708358d949af6c44b9ea3eb02c6fc /block/blk-mq-virtio.c | |
parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security (diff) | |
parent | virtio-console: avoid DMA from stack (diff) | |
download | linux-dev-54d7989f476ca57fc3c5cc71524c480ccb74c481.tar.xz linux-dev-54d7989f476ca57fc3c5cc71524c480ccb74c481.zip |
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull vhost updates from Michael Tsirkin:
"virtio, vhost: optimizations, fixes
Looks like a quiet cycle for vhost/virtio, just a couple of minor
tweaks. Most notable is automatic interrupt affinity for blk and scsi.
Hopefully other devices are not far behind"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio-console: avoid DMA from stack
vhost: introduce O(1) vq metadata cache
virtio_scsi: use virtio IRQ affinity
virtio_blk: use virtio IRQ affinity
blk-mq: provide a default queue mapping for virtio device
virtio: provide a method to get the IRQ affinity mask for a virtqueue
virtio: allow drivers to request IRQ affinity when creating VQs
virtio_pci: simplify MSI-X setup
virtio_pci: don't duplicate the msix_enable flag in struct pci_dev
virtio_pci: use shared interrupts for virtqueues
virtio_pci: remove struct virtio_pci_vq_info
vhost: try avoiding avail index access when getting descriptor
virtio_mmio: expose header to userspace
Diffstat (limited to 'block/blk-mq-virtio.c')
-rw-r--r-- | block/blk-mq-virtio.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/block/blk-mq-virtio.c b/block/blk-mq-virtio.c new file mode 100644 index 000000000000..c3afbca11299 --- /dev/null +++ b/block/blk-mq-virtio.c @@ -0,0 +1,54 @@ +/* + * 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/device.h> +#include <linux/blk-mq.h> +#include <linux/blk-mq-virtio.h> +#include <linux/virtio_config.h> +#include <linux/module.h> +#include "blk-mq.h" + +/** + * blk_mq_virtio_map_queues - provide a default queue mapping for virtio device + * @set: tagset to provide the mapping for + * @vdev: virtio device associated with @set. + * @first_vec: first interrupt vectors to use for queues (usually 0) + * + * This function assumes the virtio device @vdev 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_virtio_map_queues(struct blk_mq_tag_set *set, + struct virtio_device *vdev, int first_vec) +{ + const struct cpumask *mask; + unsigned int queue, cpu; + + if (!vdev->config->get_vq_affinity) + goto fallback; + + for (queue = 0; queue < set->nr_hw_queues; queue++) { + mask = vdev->config->get_vq_affinity(vdev, first_vec + queue); + if (!mask) + goto fallback; + + for_each_cpu(cpu, mask) + set->mq_map[cpu] = queue; + } + + return 0; +fallback: + return blk_mq_map_queues(set); +} +EXPORT_SYMBOL_GPL(blk_mq_virtio_map_queues); |