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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?bnKiijvtVMdNeDaaaEHQLW9nwfEe5+Uw9RxgkKBV832EKBVVeko1+w1dLGYh?= =?us-ascii?Q?lIOo1v3e+0YwTGFlalyZ+j2SSFoKsIrr2+Am3L0SIrLr2K7PIej6y/U2XduV?= =?us-ascii?Q?z/EZSSlra4wERqe4yesmOgo8dqQEPPQ7FNgi3ve96tUebbB27Gyo23ymRfqp?= =?us-ascii?Q?0PLKilaS4uOMbaODMk6SewOtp2LqacHnJfUWLXLyqqBP9MxBNi6TQTz5ogqR?= =?us-ascii?Q?pMf7MNUulMOid9LA4ZMfHlWwB/R3e+GBjpKytmGskZXbSfbspsmetFZDmh9W?= =?us-ascii?Q?eB5wRE9Y+1g9CCQRa3MYipm+c1Kh0O/uAunn1w2ZSJQSDIuXIv/QQDB3oPP/?= =?us-ascii?Q?CaWNvOAnMUzg8BZlgtNzol5WHvfDvHVTjIXki22VXJUAEjKSUVUPAUKGMt24?= =?us-ascii?Q?+JErWugqkE5NVBp9EhF2bCITp1K+qd1c5PWGY5vE7W0TPBQfLLQstCKmglfa?= =?us-ascii?Q?YJ7BI8olV8PGC1nZGXENR0Q0IiyVZUUzHyzUs1Hb17o8u7OIG5dSAbXSP6oP?= =?us-ascii?Q?nv6da5GdsltIw14f3+3trKHh4B5orqcpIWN7V4vAorhfIZCNUOju4BDz6i/A?= =?us-ascii?Q?DYrZ0UnWsKnPWMEaDjuzoVO5+XK18LJ2UQZyCIZNOYE9bBBuCYp0LqbAsUAq?= =?us-ascii?Q?TpbP62ari+EHoD6dZouU96TbLWKgY7icX32+jDGqTK2gKWaWLKUI9Br3hWis?= =?us-ascii?Q?5hNxlZMASHheYWmd7kQLIhABxpKPDfDb2Yr8N1Cp1JzDiz2WrGT8QLtugm0Q?= =?us-ascii?Q?8JH33LE92/b/WalEyiTMuol2M8FmCP+XN11u1KqyGN2spXGzPaEVjBg5S8Ek?= =?us-ascii?Q?Ok9H21SsRmnrD44lizWe2+A6mrJJ75NoRilmBj9uzV/z9RkvAUqTZ8yz1iG1?= =?us-ascii?Q?28rbTuDvhOJUgWHsSWCWKUTvexbsj97DNdZXQ3rqbCVKCNe3GR8U8gzvPfME?= =?us-ascii?Q?4sEGqsqVOWSUy7KZlOrOuL0SWI1fCcllcRtEOUDJsA5DVfA0NxUFMlPtD5m+?= =?us-ascii?Q?J1yeOYGCQQQzYLAxLRNRC3n94LbRDBCufe+QjQVnl/LkJyJOEiP4MwxM2NsM?= =?us-ascii?Q?xHlZId+vwgpA4DxG6DBDsYCSRC+I6tu7V4vEWsfw9in4y0W0Xg3mGmox/wiY?= =?us-ascii?Q?gNX9niALaljHsGdU8gL1LNLtyXWPOD8iVt3q1j4VzTxLlldptCCmzV56w2y7?= =?us-ascii?Q?X+wJ4zvhEtEzORBbOHfLeaFe5WLDaVZJQ6Y62uW5sKI9MCDO6DesSjZNeiM1?= =?us-ascii?Q?zdMvaiARBd8jQSG3EbrzY8B8/YZwpA/bBUXDtHe6tZjWKirqDTu8GzXev/Ab?= =?us-ascii?Q?8UqkTfu8iclmShj/GwcrWhYXN762rWQRAC8pFffm4JbrsuNXe9A7nqM2y0Ls?= =?us-ascii?Q?I4JkrzscX7oNNz4CG+LzYPJDUnDUfHMqWgYPy7q0R8Br7EQEeCjf/NdKnMOT?= =?us-ascii?Q?rovzSTuooxJWGoUCR61zy+bBlr7Q3Pbf3U8lS+w9O807BAQ0nq8oynHE1IfC?= =?us-ascii?Q?D4t4Hf+3zseLn+BdHwfQc4pNsy0bdf7qWlm8GdPa2oR5MHHR3MBDgEGDqmBa?= =?us-ascii?Q?zXPN9GcBBGd63qlmN17Ja7rOW2a+ZawuMUFtqgnKwcmjyg/ou8sQ+0AzRqrn?= =?us-ascii?Q?olPGhPRxbaLlepS2WlmF2NCZK3YNsnzYyHRAYMJW8GMB5lQplD1chUqOb2+n?= =?us-ascii?Q?vhWLjsTseGdUbs7ClEjr3ZlGFi4xGqRl7GPtj4jyBxKYG4CU?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: b8cfc24d-4a19-4139-cd16-08de5796a643 X-MS-Exchange-CrossTenant-AuthSource: PRASPRMB0004.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Jan 2026 20:09:28.0663 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: fV7vpciDV/igIivPu7AVOvhvRmN8PXAXZnK+7RMtw2mnnqIA34SrfeTcU8FXKf4ILUea6hpYM0OqgKS7n3vhUw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI0PR04MB12234 On Sun, Jan 18, 2026 at 10:54:13PM +0900, Koichiro Den wrote: > Not all NTB implementations are able to naturally do DMA mapping through > the NTB PCI device itself (e.g. due to IOMMU topology or non-PCI backing > devices). > > Add an optional .get_dma_dev() callback and helper so clients can use > the appropriate struct device for DMA API allocations and mappings. > > Signed-off-by: Koichiro Den > --- > include/linux/ntb.h | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/include/linux/ntb.h b/include/linux/ntb.h > index aa888219732a..7ac8cb13e90d 100644 > --- a/include/linux/ntb.h > +++ b/include/linux/ntb.h > @@ -262,6 +262,7 @@ struct ntb_mw_subrange { > * @msg_clear_mask: See ntb_msg_clear_mask(). > * @msg_read: See ntb_msg_read(). > * @peer_msg_write: See ntb_peer_msg_write(). > + * @get_dma_dev: See ntb_get_dma_dev(). > * @get_private_data: See ntb_get_private_data(). > */ > struct ntb_dev_ops { > @@ -339,6 +340,7 @@ struct ntb_dev_ops { > int (*msg_clear_mask)(struct ntb_dev *ntb, u64 mask_bits); > u32 (*msg_read)(struct ntb_dev *ntb, int *pidx, int midx); > int (*peer_msg_write)(struct ntb_dev *ntb, int pidx, int midx, u32 msg); > + struct device *(*get_dma_dev)(struct ntb_dev *ntb); > void *(*get_private_data)(struct ntb_dev *ntb); > }; > > @@ -405,6 +407,7 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops) > !ops->peer_msg_write == !ops->msg_count && > > /* Miscellaneous optional callbacks */ > + /* ops->get_dma_dev && */ > /* ops->get_private_data && */ > 1; > } > @@ -1614,6 +1617,21 @@ static inline int ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx, > return ntb->ops->peer_msg_write(ntb, pidx, midx, msg); > } > > +/** > + * ntb_get_dma_dev() - get the device suitable for DMA mapping > + * @ntb: NTB device context. > + * > + * Retrieve a struct device which is suitable for DMA mapping. > + * > + * Return: Pointer to struct device. > + */ > +static inline struct device __maybe_unused *ntb_get_dma_dev(struct ntb_dev *ntb) I remember if there are inline, needn't __maybe_unused. Reviewed-by: Frank Li > +{ > + if (!ntb->ops->get_dma_dev) > + return ntb->dev.parent; > + return ntb->ops->get_dma_dev(ntb); > +} > + > /** > * ntb_get_private_data() - get private data specific to the hardware driver > * @ntb: NTB device context. > -- > 2.51.0 >