Merge branch 'nvme-5.2' of git://git.infradead.org/nvme into for-5.2/block

Pull NVMe changes from Christoph:

"Below is the first batch of nvme updates for 5.2. This includes the
performance improvements for single segment I/O on PCIe, which introduce
new block helpers, so it might be a good idea to get them in early.

 - various performance optimizations in the PCIe code (Keith and me)
 - new block helpers to support the above (me)
 - nvmet error conversion cleanup (me)
 - nvmet-fc variable sized array cleanup (Gustavo)
 - passthrough ioctl error printk cleanup (Kenneth)
 - small nvmet fixes (Max)
 - endianess conversion cleanup (Max)
 - nvmet-tcp faspath completion optimization (Sagi)"

* 'nvme-5.2' of git://git.infradead.org/nvme: (24 commits)
  nvme: log the error status on Identify Namespace failure
  nvmet: add safety check for subsystem lock during nvmet_ns_changed
  nvmet: never fail double namespace enablement
  nvme-pci: tidy up nvme_map_data
  nvme-pci: optimize mapping single segment requests using SGLs
  nvme-pci: optimize mapping of small single segment requests
  nvme-pci: remove the inline scatterlist optimization
  nvme-pci: split metadata handling from nvme_map_data / nvme_unmap_data
  nvme-pci: do not build a scatterlist to map metadata
  nvme-pci: only call nvme_unmap_data for requests transferring data
  nvme-pci: merge nvme_free_iod into nvme_unmap_data
  nvme-pci: move the call to nvme_cleanup_cmd out of nvme_unmap_data
  nvme-pci: remove nvme_init_iod
  block: add dma_map_bvec helper
  block: add a rq_dma_dir helper
  block: add a rq_integrity_vec helper
  block: add a req_bvec helper
  nvme-pci: remove unused nvme_iod member
  nvme-pci: remove q_dmadev from nvme_queue
  nvme-pci: use a flag for polled queues
  ...