[PATCH-part-2 4/9] nvme-pci: remove "dma_len" from nvme_iod

[Keith Busch]

From: Keith Busch <kbusch at kernel.org>

This is redundant data that we can get from sgl nents and request data
length. Remove it to make the struct smaller.

Signed-off-by: Keith Busch <kbusch at kernel.org>
---
 drivers/nvme/host/pci.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 77d42eaada742..3af4a226497c9 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -233,7 +233,6 @@ struct nvme_iod {
 	bool aborted;
 	s8 nr_allocations;	/* PRP list pool allocations. 0 means small
 				   pool in use */
-	unsigned int dma_len;	/* length of single DMA segment mapping */
 	dma_addr_t first_dma;
 	dma_addr_t meta_dma;
 	struct sg_table sgt;
@@ -554,14 +553,12 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 
-	if (iod->dma_len) {
-		dma_unmap_page(dev->dev, iod->first_dma, iod->dma_len,
+	if (!iod->sgt.nents) {
+		dma_unmap_page(dev->dev, iod->first_dma, blk_rq_bytes(req),
 			       rq_dma_dir(req));
 		return;
 	}
 
-	WARN_ON_ONCE(!iod->sgt.nents);
-
 	dma_unmap_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), 0);
 
 	if (iod->nr_allocations == 0)
@@ -751,7 +748,6 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
 	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
 	if (dma_mapping_error(dev->dev, iod->first_dma))
 		return BLK_STS_RESOURCE;
-	iod->dma_len = bv->bv_len;
 
 	cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma);
 	if (bv->bv_len > first_prp_len)
@@ -770,11 +766,10 @@ static blk_status_t nvme_setup_sgl_simple(struct nvme_dev *dev,
 	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
 	if (dma_mapping_error(dev->dev, iod->first_dma))
 		return BLK_STS_RESOURCE;
-	iod->dma_len = bv->bv_len;
 
 	cmnd->flags = NVME_CMD_SGL_METABUF;
 	cmnd->dptr.sgl.addr = cpu_to_le64(iod->first_dma);
-	cmnd->dptr.sgl.length = cpu_to_le32(iod->dma_len);
+	cmnd->dptr.sgl.length = cpu_to_le32(bv->bv_len);
 	cmnd->dptr.sgl.type = NVME_SGL_FMT_DATA_DESC << 4;
 	return BLK_STS_OK;
 }
@@ -786,7 +781,6 @@ static blk_status_t __nvme_map_data(struct nvme_dev *dev, struct request *req,
 	blk_status_t ret = BLK_STS_RESOURCE;
 	int rc;
 
-	iod->dma_len = 0;
 	iod->sgt.sgl = mempool_alloc(dev->iod_mempool, GFP_ATOMIC);
 	if (!iod->sgt.sgl)
 		return BLK_STS_RESOURCE;
-- 
2.43.5