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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?zKUJ9m/08qrvwmqfYC7oCQXc1GSgIgyBalOY2PRN3ygzeXfv5wBVHKIzQIXr?= =?us-ascii?Q?42K0C76hU8qa9CdURs8o3m+iIrS04GiNaa2a5CsiyoQG8QrpdXAA2jFTSeQC?= =?us-ascii?Q?rwvaUpefhN7FJ4NSDiDJKVY0vdZukfp0w3XGnuUah6ddlxiuO7W4AXGWuGTp?= =?us-ascii?Q?UKoLP9q+N9bqTDsOa0Xl6HGYux6VFoWtvSzKgcjZYg+SpoqkIFCvvcFwGSzZ?= =?us-ascii?Q?nx8tIeiv7QEF4DLVgDlNNKwSiLGE+7LEbe9Va5nqpHlN49kCKSb+YAgC3iqr?= =?us-ascii?Q?UIc/s0Nbv/zBtyTs0j0eBqUfy0Eu1AUrLBSall0wBmOKs7KTm6ZVzrdapLkP?= =?us-ascii?Q?h2IWcT8UUG2H0SOWLeNP7ZAZvWl5pJtklLhBCN1VMvnge13tgceI8G+pdWud?= =?us-ascii?Q?yml3/8fRUO+21gISTAjz3KR2+4d2vTulHAfllHh+eGeu4GAbovDPx8+iHO0g?= =?us-ascii?Q?qRxLyWRuE0ot/8MRCeaIgPgI9sPgbgCZgKJzXZJNv1urGA1tYIDd7tML/a9q?= =?us-ascii?Q?qQj82vjMXAnZqqajo6zYrp7b/Kptv01km96xRXIEUKUk+jU98YX8YNQxlQX6?= =?us-ascii?Q?Mw3c7G8oohwTi1iUEa/6DJDW+u47MBjHDQwFMiCFqPSPpnHL+6EpNXNjmifq?= =?us-ascii?Q?Bt8QTn+wgluQCmdcfZmV/zaRlI40vVbUKq+Gmamdd+GQuAJ0uOFKh6mNy+Dr?= =?us-ascii?Q?h1j3LOSfkMelfoUMJ8r2YiXeJFf2MgwGNSpeV+GQCHczZIMQOei7sYS4dkiy?= =?us-ascii?Q?E5zNDHJwhB6AMOlsDMypJGtp64jBToeb7Jv8CS5N9V285pl/3/5qfEq0cA5w?= =?us-ascii?Q?dLxo5IGXkUauyDnxvEPO8U+NQDCc5RV8Zx7IMAtOqVsXPVNN41T+QIvSP9w6?= =?us-ascii?Q?73ugOdB9ZVssJzJLSeWIu6t/FvOt7t7ntw4mAYd8mj7BMST/VhSEk7BJargQ?= =?us-ascii?Q?JJJecVn7NO2xhUMuSbvIc1dw5iD4LQONlfav2c1LMF0WsBJcTa0RH0dfhZHf?= =?us-ascii?Q?FKrRL/DVeOu63Ov2km5ROdfShBMlfiTpK4y4YeZU4O7c8jPT6tkEPySfxXL6?= =?us-ascii?Q?fOQfqPFDrOMuAwjF26Ig+w8TRdTgEW7VdDJXYepyqungZ27gm2OGkSsETmLc?= =?us-ascii?Q?oZevacFCTFRS15vgTC137ch9Eoe+KrT6wevnYKGugLpuXns78Bdg/GDbfyoQ?= =?us-ascii?Q?IwmDfpyzuGtenfi5zH8FrePnt0MbElZIbFp2WYei3ibbhh7L+gdGVB9I30II?= =?us-ascii?Q?JULHTYMsF6KX4j7u3m9ULYGL4uKKkSDPMKf3Ag8dB9/gW3o/ruGoj+JE/k9i?= =?us-ascii?Q?tWXU53+C3tJ7oc59Y/IlSlUvwokIiNR14bLuy6hy4vFS7J84k5RMqmB7uJef?= =?us-ascii?Q?8elGmTAOCLhk1YeSu9iF3GhKI1OhWVP3UISOrlOcSbUgAIoiHNb3yYHm3BXN?= =?us-ascii?Q?ZzqZ4Av9PVWwXUMwvGCttv7gdh+8kMsdMIEo7LvzGqUQOB9c8QpUkzJGFMOr?= =?us-ascii?Q?mlGinBZEjzF1YmK+UUxqMWHAqSofsoWW1HLT68xj2Kj/HUBthMK0m3+0Qfs4?= =?us-ascii?Q?tn1FuG8+DtsVxNETqSj6gkTN4N9i6Oh0p6RpAmagNfGLE8t4SquFfxPjqNQu?= =?us-ascii?Q?H057Iv2xdADReBRNcjFRrPTwPikvPVl/4zRxGs91/9bvizpNRBA37rifKOnO?= =?us-ascii?Q?V4wXVOu4R80w8aSnZLzVBhTUgwo+niY2pc3Z+kfLokVUpUq/?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5a9d85fc-3247-4a60-dcc6-08de890cbae9 X-MS-Exchange-CrossTenant-AuthSource: PA4PR04MB9366.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Mar 2026 18:48:10.4348 (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: bWP20sGEQfMIgpl5DNwO1TV2aKMpLIFDSvUbOzgVaR6rHL3F5FbBUf7mbfJ6E2OEH59NGaJ0ybkGcWErzjFkYA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXPR04MB9422 On Mon, Mar 02, 2026 at 04:14:27PM +0900, Koichiro Den wrote: > Some endpoint platforms cannot use platform MSI / GIC ITS to implement > EP-side doorbells. In those cases, EPF drivers cannot provide an > interrupt-driven doorbell and often fall back to polling. > > Add an "embedded" doorbell backend that uses a controller-integrated > doorbell target (e.g. DesignWare integrated eDMA interrupt-emulation > doorbell). > > The backend locates the doorbell register and a corresponding Linux IRQ > via the EPC aux-resource API. If the doorbell register is already > exposed via a fixed BAR mapping, provide BAR+offset. Otherwise provide > the DMA address returned by dma_map_resource() (which may be an IOVA > when an IOMMU is enabled) so EPF drivers can map it into BAR space. > > When MSI doorbell allocation fails with -ENODEV, > pci_epf_alloc_doorbell() falls back to this embedded backend. > > Signed-off-by: Koichiro Den > --- ... > + */ > + if (doorbell->bar == NO_BAR) { > + phys_base = addr & PAGE_MASK; > + off = addr - phys_base; > + map_size = PAGE_ALIGN(off + sizeof(u32)); > + > + iova_base = dma_map_resource(epc->dev.parent, phys_base, > + map_size, DMA_FROM_DEVICE, 0); DB should write. Is it DMA_TO_DEVICE? Frank > > /** > -- > 2.51.0 >