Re: [RFC PATCH v4 18/38] NTB: ntb_transport: Use ntb_get_dma_dev()

Frank Li
2026-01-19T20:39:04Z

On Sun, Jan 18, 2026 at 10:54:20PM +0900, Koichiro Den wrote:
> Replace direct use of ntb->pdev with ntb_get_dma_dev() for DMA-safe
> allocations and frees. This allows ntb_transport to operate on NTB
> implementations that are not backed by a PCI device from IOMMU
> perspective.
>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
Reviewed-by: Frank Li <Frank.Li@nxp.com>
> drivers/ntb/ntb_transport.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 6ed680d0470f..7b320249629c 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -771,13 +771,13 @@ 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 *dev = ntb_get_dma_dev(nt->ndev);
>
> - if (!mw->virt_addr)
> + if (!dev || !mw->virt_addr)
> return;
>
> ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
> - dma_free_coherent(&pdev->dev, mw->alloc_size,
> + dma_free_coherent(dev, mw->alloc_size,
> mw->alloc_addr, mw->dma_addr);
> mw->xlat_size = 0;
> mw->buff_size = 0;
> @@ -847,13 +847,13 @@ 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 *dev = ntb_get_dma_dev(nt->ndev);
> size_t xlat_size, buff_size;
> resource_size_t xlat_align;
> resource_size_t xlat_align_size;
> int rc;
>
> - if (!size)
> + if (!dev || !size)
> return -EINVAL;
>
> rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
> @@ -876,12 +876,12 @@ 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, 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, dev, xlat_align);
> if (rc) {
> - dev_err(&pdev->dev,
> + dev_err(dev,
> "Unable to alloc aligned MW buff\n");
> mw->xlat_size = 0;
> mw->buff_size = 0;
> @@ -894,7 +894,7 @@ 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(dev, "Unable to set mw%d translation", num_mw);
> ntb_free_mw(nt, num_mw);
> return -EIO;
> }
> --
> 2.51.0
>