[PATCH v9 23/24] nvme-pci: convert to blk_rq_dma_map

[Keith Busch]

On Wed, Apr 23, 2025 at 11:13:14AM +0300, Leon Romanovsky wrote:
> +static bool nvme_try_setup_sgl_simple(struct nvme_dev *dev, struct request *req,
> +				      struct nvme_rw_command *cmnd,
> +				      struct blk_dma_iter *iter)
> +{
> +	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
> +	struct bio_vec bv = req_bvec(req);
> +
> +	if (IS_ENABLED(CONFIG_PCI_P2PDMA) && (req->cmd_flags & REQ_P2PDMA))
> +		return false;
> +
> +	if ((bv.bv_offset & (NVME_CTRL_PAGE_SIZE - 1)) + bv.bv_len >
> +			NVME_CTRL_PAGE_SIZE * 2)
> +		return false;

We don't need this check for SGLs. If we have a single segment, we can
put it in a single SG element no matter how large it is.