[PATCH 2/2] nvme: convert metadata mapping to dma iter
Keith Busch
kbusch at meta.com
Wed Jun 25 13:44:45 PDT 2025
From: Keith Busch <kbusch at kernel.org>
Aligns data and metadata to the similar dma mapping scheme and removes
one more user of the scatter-gather dma mapping.
Signed-off-by: Keith Busch <kbusch at kernel.org>
---
drivers/nvme/host/pci.c | 69 +++++++++++++----------------------------
1 file changed, 21 insertions(+), 48 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 38be1505dbd96..f82ef19fa0a3a 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -270,13 +270,13 @@ struct nvme_iod {
struct nvme_command cmd;
u8 flags;
u8 nr_descriptors;
+ u8 nr_meta_descriptors;
unsigned int total_len;
struct dma_iova_state dma_state;
void *descriptors[NVME_MAX_NR_DESCRIPTORS];
dma_addr_t meta_dma;
- struct sg_table meta_sgt;
struct nvme_sgl_desc *meta_descriptor;
};
@@ -1010,70 +1010,39 @@ static blk_status_t nvme_map_data(struct request *req)
return nvme_pci_setup_data_prp(req, &iter);
}
-static void nvme_pci_sgl_set_data_sg(struct nvme_sgl_desc *sge,
- struct scatterlist *sg)
-{
- sge->addr = cpu_to_le64(sg_dma_address(sg));
- sge->length = cpu_to_le32(sg_dma_len(sg));
- sge->type = NVME_SGL_FMT_DATA_DESC << 4;
-}
-
static blk_status_t nvme_pci_setup_meta_sgls(struct request *req)
{
struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
- struct nvme_dev *dev = nvmeq->dev;
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ struct nvme_dev *dev = nvmeq->dev;
struct nvme_sgl_desc *sg_list;
- struct scatterlist *sgl, *sg;
- unsigned int entries;
+ struct blk_dma_iter iter;
dma_addr_t sgl_dma;
- int rc, i;
-
- iod->meta_sgt.sgl = mempool_alloc(dev->iod_meta_mempool, GFP_ATOMIC);
- if (!iod->meta_sgt.sgl)
- return BLK_STS_RESOURCE;
-
- sg_init_table(iod->meta_sgt.sgl, req->nr_integrity_segments);
- iod->meta_sgt.orig_nents = blk_rq_map_integrity_sg(req,
- iod->meta_sgt.sgl);
- if (!iod->meta_sgt.orig_nents)
- goto out_free_sg;
+ int i = 0;
- rc = dma_map_sgtable(dev->dev, &iod->meta_sgt, rq_dma_dir(req),
- DMA_ATTR_NO_WARN);
- if (rc)
- goto out_free_sg;
+ if (!blk_rq_integrity_dma_map_iter_start(req, dev->dev, &iter))
+ return iter.status;
sg_list = dma_pool_alloc(nvmeq->descriptor_pools.small, GFP_ATOMIC,
&sgl_dma);
if (!sg_list)
- goto out_unmap_sg;
+ return BLK_STS_RESOURCE;
- entries = iod->meta_sgt.nents;
iod->meta_descriptor = sg_list;
iod->meta_dma = sgl_dma;
iod->cmd.common.flags = NVME_CMD_SGL_METASEG;
iod->cmd.common.metadata = cpu_to_le64(sgl_dma);
- sgl = iod->meta_sgt.sgl;
- if (entries == 1) {
- nvme_pci_sgl_set_data_sg(sg_list, sgl);
- return BLK_STS_OK;
- }
-
sgl_dma += sizeof(*sg_list);
- nvme_pci_sgl_set_seg(sg_list, sgl_dma, entries);
- for_each_sg(sgl, sg, entries, i)
- nvme_pci_sgl_set_data_sg(&sg_list[i + 1], sg);
- return BLK_STS_OK;
+ do {
+ nvme_pci_sgl_set_data(&sg_list[++i], &iter);
+ } while (blk_rq_integrity_dma_map_iter_next(req, dev->dev, &iter));
-out_unmap_sg:
- dma_unmap_sgtable(dev->dev, &iod->meta_sgt, rq_dma_dir(req), 0);
-out_free_sg:
- mempool_free(iod->meta_sgt.sgl, dev->iod_meta_mempool);
- return BLK_STS_RESOURCE;
+ nvme_pci_sgl_set_seg(sg_list, sgl_dma, i);
+ iod->nr_meta_descriptors = i;
+ return BLK_STS_OK;
}
static blk_status_t nvme_pci_setup_meta_mptr(struct request *req)
@@ -1086,6 +1055,7 @@ static blk_status_t nvme_pci_setup_meta_mptr(struct request *req)
if (dma_mapping_error(nvmeq->dev->dev, iod->meta_dma))
return BLK_STS_IOERR;
iod->cmd.common.metadata = cpu_to_le64(iod->meta_dma);
+ iod->nr_meta_descriptors = 0;
return BLK_STS_OK;
}
@@ -1107,7 +1077,6 @@ static blk_status_t nvme_prep_rq(struct request *req)
iod->flags = 0;
iod->nr_descriptors = 0;
iod->total_len = 0;
- iod->meta_sgt.nents = 0;
ret = nvme_setup_cmd(req->q->queuedata, req);
if (ret)
@@ -1222,19 +1191,23 @@ static __always_inline void nvme_unmap_metadata(struct request *req)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
+ struct nvme_sgl_desc *sg_list = iod->meta_descriptor;
+ enum dma_data_direction dir = rq_dma_dir(req);
struct nvme_dev *dev = nvmeq->dev;
+ int i;
- if (!iod->meta_sgt.nents) {
+ if (!iod->nr_meta_descriptors) {
dma_unmap_page(dev->dev, iod->meta_dma,
rq_integrity_vec(req).bv_len,
rq_dma_dir(req));
return;
}
+ for (i = 1; i <= iod->nr_meta_descriptors; i++)
+ dma_unmap_page(dev->dev, le64_to_cpu(sg_list[i].addr),
+ le32_to_cpu(sg_list[i].length), dir);
dma_pool_free(nvmeq->descriptor_pools.small, iod->meta_descriptor,
iod->meta_dma);
- dma_unmap_sgtable(dev->dev, &iod->meta_sgt, rq_dma_dir(req), 0);
- mempool_free(iod->meta_sgt.sgl, dev->iod_meta_mempool);
}
static __always_inline void nvme_pci_unmap_rq(struct request *req)
--
2.47.1
More information about the Linux-nvme
mailing list