[PATCH v6 16/16] nvme-pci: unmap MMIO pages with appropriate interface

Leon Romanovsky
2025-09-09T13:29:21Z

Block layer maps MMIO memory through dma_map_phys() interface
with help of DMA_ATTR_MMIO attribute. There is a need to unmap
that memory with the appropriate unmap function, something which
wasn't possible before adding new REQ attribute to block layer in
previous patch.

Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/nvme/host/pci.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 2c6d9506b1725..f8ecc0e0f576d 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -682,11 +682,15 @@ static void nvme_free_prps(struct request *req)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
+ unsigned int attrs = 0;
unsigned int i;

+ if (req->cmd_flags & REQ_MMIO)
+ attrs = DMA_ATTR_MMIO;
+
for (i = 0; i < iod->nr_dma_vecs; i++)
- dma_unmap_page(nvmeq->dev->dev, iod->dma_vecs[i].addr,
- iod->dma_vecs[i].len, rq_dma_dir(req));
+ dma_unmap_phys(nvmeq->dev->dev, iod->dma_vecs[i].addr,
+ iod->dma_vecs[i].len, rq_dma_dir(req), attrs);
mempool_free(iod->dma_vecs, nvmeq->dev->dmavec_mempool);
}

@@ -699,15 +703,19 @@ static void nvme_free_sgls(struct request *req)
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 attrs = 0;
+
+ if (req->cmd_flags & REQ_MMIO)
+ attrs = DMA_ATTR_MMIO;

if (iod->nr_descriptors) {
unsigned int nr_entries = sqe_dma_len / sizeof(*sg_list), i;

for (i = 0; i < nr_entries; i++)
- dma_unmap_page(dma_dev, le64_to_cpu(sg_list[i].addr),
- le32_to_cpu(sg_list[i].length), dir);
+ dma_unmap_phys(dma_dev, le64_to_cpu(sg_list[i].addr),
+ le32_to_cpu(sg_list[i].length), dir, attrs);
} else {
- dma_unmap_page(dma_dev, sqe_dma_addr, sqe_dma_len, dir);
+ dma_unmap_phys(dma_dev, sqe_dma_addr, sqe_dma_len, dir, attrs);
}
}

--
2.51.0