[PATCH v1 16/16] nvme-pci: unmap MMIO pages with appropriate interface

Leon Romanovsky leon at kernel.org
Mon Aug 4 22:42:50 AEST 2025


From: Leon Romanovsky <leonro at nvidia.com>

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.

Signed-off-by: Leon Romanovsky <leonro at 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 071efec25346f..0b624247948c5 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);
 	}
 }
 
-- 
2.50.1



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