858299dc61
Add a new blk_rq_dma_map / blk_rq_dma_unmap pair that does away with the wasteful scatterlist structure. Instead it uses the mapping iterator to either add segments to the IOVA for IOMMU operations, or just maps them one by one for the direct mapping. For the IOMMU case instead of a scatterlist with an entry for each segment, only a single [dma_addr,len] pair needs to be stored for processing a request, and for the direct mapping the per-segment allocation shrinks from [page,offset,len,dma_addr,dma_len] to just [dma_addr,len]. One big difference to the scatterlist API, which could be considered downside, is that the IOVA collapsing only works when the driver sets a virt_boundary that matches the IOMMU granule. For NVMe this is done already so it works perfectly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Link: https://lore.kernel.org/r/20250625113531.522027-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| cxl | ||
| drm | ||
| dt-bindings | ||
| hyperv | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||
| Kbuild | ||