Commit ae582935 authored by Keith Busch's avatar Keith Busch Committed by Christoph Hellwig
Browse files

nvme-pci: use mapped entries for sgl decision 



The driver uses the dma entries for setting up its command's SGL/PRP
lists. The dma mapping might have fewer entries than the physical
segments, so check the dma mapped count to determine which nvme data
layout method is more optimal.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 01df742d

drivers/nvme/host/pci.c

+3 −3
Original line number Diff line number Diff line
@@ -515,10 +515,10 @@ static void **nvme_pci_iod_list(struct request *req) 
	return (void **)(iod->sgt.sgl + blk_rq_nr_phys_segments(req));

}



static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)

static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req,

				     int nseg)

{

	struct nvme_queue *nvmeq = req->mq_hctx->driver_data;

	int nseg = blk_rq_nr_phys_segments(req);

	unsigned int avg_seg_size;



	avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), nseg);
@@ -818,7 +818,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, 
		goto out_free_sg;

	}



	iod->use_sgl = nvme_pci_use_sgls(dev, req);

	iod->use_sgl = nvme_pci_use_sgls(dev, req, iod->sgt.nents);

	if (iod->use_sgl)

		ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw);

	else