[PATCH 5.10/5.15 2/3] NTB: ntb_transport: Use ntb_get_dma_dev() for DMA buffers

[Mikhail Dmitrichenko <mdmitrichenko@astralinux.ru>]

From: Koichiro Den <den@valinux.co.jp>

commit 852b94ff92cbe26a0dbb15eed9474f5493767f3b upstream.

ntb_transport currently uses ndev->pdev->dev for coherent allocations
and frees.

Switch the coherent buffer allocation/free paths to use
ntb_get_dma_dev(), so ntb_transport can work with NTB implementations
where the NTB PCI function is not the right device to use for DMA
mappings.

Suggested-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260306031443.1911860-3-den@valinux.co.jp
Stable-dep-of: da6d997ac556 ("ntb: Store original DMA address for future release")
Signed-off-by: Mikhail Dmitrichenko <mdmitrichenko@astralinux.ru>
---
Prerequisite for the CVE-2026-80884 fix.

 drivers/ntb/ntb_transport.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 94a8e294b7f21..2fca53b8e486d 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -793,13 +793,13 @@ static void ntb_transport_msi_desc_changed(void *data)
 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 {
 	struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
-	struct pci_dev *pdev = nt->ndev->pdev;
+	struct device *dma_dev = ntb_get_dma_dev(nt->ndev);
 
 	if (!mw->virt_addr)
 		return;
 
 	ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
-	dma_free_coherent(&pdev->dev, mw->alloc_size,
+	dma_free_coherent(dma_dev, mw->alloc_size,
 			  mw->alloc_addr, mw->dma_addr);
 	mw->xlat_size = 0;
 	mw->buff_size = 0;
@@ -856,7 +856,7 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 		      resource_size_t size)
 {
 	struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
-	struct pci_dev *pdev = nt->ndev->pdev;
+	struct device *dma_dev = ntb_get_dma_dev(nt->ndev);
 	size_t xlat_size, buff_size;
 	resource_size_t xlat_align;
 	resource_size_t xlat_align_size;
@@ -885,12 +885,12 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 	mw->buff_size = buff_size;
 	mw->alloc_size = buff_size;
 
-	rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
+	rc = ntb_alloc_mw_buffer(mw, dma_dev, xlat_align);
 	if (rc) {
 		mw->alloc_size *= 2;
-		rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
+		rc = ntb_alloc_mw_buffer(mw, dma_dev, xlat_align);
 		if (rc) {
-			dev_err(&pdev->dev,
+			dev_err(dma_dev,
 				"Unable to alloc aligned MW buff\n");
 			mw->xlat_size = 0;
 			mw->buff_size = 0;
@@ -903,7 +903,7 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 	rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 			      mw->xlat_size);
 	if (rc) {
-		dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
+		dev_err(dma_dev, "Unable to set mw%d translation", num_mw);
 		ntb_free_mw(nt, num_mw);
 		return -EIO;
 	}
-- 
2.43.0