blk-mq-rdma: remove queue mapping helper for rdma devices

No rdma device exposes its irq vectors affinity today. So the only
mapping that we have left, is the default blk_mq_map_queues, which
we fallback to anyways. Also fixup the only consumer of this helper
(nvme-rdma).

Remove this now dead code.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

block/Kconfig

@@ -215,11 +215,6 @@ config BLK_MQ_VIRTIO
 	depends on VIRTIO
 	default y
 
-config BLK_MQ_RDMA
-	bool
-	depends on INFINIBAND
-	default y
-
 config BLK_PM
 	def_bool PM
 

block/Makefile

@@ -30,7 +30,6 @@ obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o
 obj-$(CONFIG_BLK_DEV_INTEGRITY_T10)	+= t10-pi.o
 obj-$(CONFIG_BLK_MQ_PCI)	+= blk-mq-pci.o
 obj-$(CONFIG_BLK_MQ_VIRTIO)	+= blk-mq-virtio.o
-obj-$(CONFIG_BLK_MQ_RDMA)	+= blk-mq-rdma.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o

block/blk-mq-rdma.c

@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2017 Sagi Grimberg.
- */
-#include <linux/blk-mq.h>
-#include <linux/blk-mq-rdma.h>
-#include <rdma/ib_verbs.h>
-
-/**
- * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
- * @map:	CPU to hardware queue map.
- * @dev:	rdma device to provide a mapping for.
- * @first_vec:	first interrupt vectors to use for queues (usually 0)
- *
- * This function assumes the rdma device @dev has at least as many available
- * interrupt vetors as @set has queues.  It will then query it's affinity mask
- * and built queue mapping that maps a queue to the CPUs that have irq affinity
- * for the corresponding vector.
- *
- * In case either the driver passed a @dev with less vectors than
- * @set->nr_hw_queues, or @dev does not provide an affinity mask for a
- * vector, we fallback to the naive mapping.
- */
-void blk_mq_rdma_map_queues(struct blk_mq_queue_map *map,
-		struct ib_device *dev, int first_vec)
-{
-	const struct cpumask *mask;
-	unsigned int queue, cpu;
-
-	for (queue = 0; queue < map->nr_queues; queue++) {
-		mask = ib_get_vector_affinity(dev, first_vec + queue);
-		if (!mask)
-			goto fallback;
-
-		for_each_cpu(cpu, mask)
-			map->mq_map[cpu] = map->queue_offset + queue;
-	}
-
-	return;
-
-fallback:
-	blk_mq_map_queues(map);
-}
-EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);

drivers/nvme/host/rdma.c

@@ -12,7 +12,6 @@
 #include <linux/string.h>
 #include <linux/atomic.h>
 #include <linux/blk-mq.h>
-#include <linux/blk-mq-rdma.h>
 #include <linux/blk-integrity.h>
 #include <linux/types.h>
 #include <linux/list.h>
@@ -2159,10 +2158,8 @@ static void nvme_rdma_map_queues(struct blk_mq_tag_set *set)
 			ctrl->io_queues[HCTX_TYPE_DEFAULT];
 		set->map[HCTX_TYPE_READ].queue_offset = 0;
 	}
-	blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_DEFAULT],
+	blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
-			ctrl->device->dev, 0);
+	blk_mq_map_queues(&set->map[HCTX_TYPE_READ]);
-	blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_READ],
-			ctrl->device->dev, 0);
 
 	if (opts->nr_poll_queues && ctrl->io_queues[HCTX_TYPE_POLL]) {
 		/* map dedicated poll queues only if we have queues left */

include/linux/blk-mq-rdma.h

@@ -1,11 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_BLK_MQ_RDMA_H
-#define _LINUX_BLK_MQ_RDMA_H
-
-struct blk_mq_tag_set;
-struct ib_device;
-
-void blk_mq_rdma_map_queues(struct blk_mq_queue_map *map,
-		struct ib_device *dev, int first_vec);
-
-#endif /* _LINUX_BLK_MQ_RDMA_H */