Commit f0887e2a authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

nvme-pci: create common sgl unmapping helper 



This can be reused by metadata sgls once that starts using the blk-mq
dma api.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20250813153153.3260897-9-kbusch@meta.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c16b52a0

drivers/nvme/host/pci.c

+14 −15
Original line number Diff line number Diff line
@@ -693,25 +693,23 @@ static void nvme_free_prps(struct request *req) 
	mempool_free(iod->dma_vecs, nvmeq->dev->dmavec_mempool);

}



static void nvme_free_sgls(struct request *req)

static void nvme_free_sgls(struct request *req, struct nvme_sgl_desc *sge,

		struct nvme_sgl_desc *sg_list)

{

	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);

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

	struct device *dma_dev = nvmeq->dev->dev;

	dma_addr_t sqe_dma_addr = le64_to_cpu(iod->cmd.common.dptr.sgl.addr);

	unsigned int sqe_dma_len = le32_to_cpu(iod->cmd.common.dptr.sgl.length);

	struct nvme_sgl_desc *sg_list = iod->descriptors[0];

	enum dma_data_direction dir = rq_dma_dir(req);

	unsigned int len = le32_to_cpu(sge->length);

	struct device *dma_dev = nvmeq->dev->dev;

	unsigned int i;



	if (iod->nr_descriptors) {

		unsigned int nr_entries = sqe_dma_len / sizeof(*sg_list), i;

	if (sge->type == (NVME_SGL_FMT_DATA_DESC << 4)) {

		dma_unmap_page(dma_dev, le64_to_cpu(sge->addr), len, dir);

		return;

	}



		for (i = 0; i < nr_entries; i++)

	for (i = 0; i < len / sizeof(*sg_list); i++)

		dma_unmap_page(dma_dev, le64_to_cpu(sg_list[i].addr),

			le32_to_cpu(sg_list[i].length), dir);

	} else {

		dma_unmap_page(dma_dev, sqe_dma_addr, sqe_dma_len, dir);

	}

}



static void nvme_unmap_data(struct request *req)
@@ -731,7 +729,8 @@ static void nvme_unmap_data(struct request *req) 
	if (!blk_rq_dma_unmap(req, dma_dev, &iod->dma_state, iod->total_len,

				iod->flags & IOD_P2P_BUS_ADDR)) {

		if (nvme_pci_cmd_use_sgl(&iod->cmd))

			nvme_free_sgls(req);

			nvme_free_sgls(req, iod->descriptors[0],

				       &iod->cmd.common.dptr.sgl);

		else

			nvme_free_prps(req);

	}