diff options
Diffstat (limited to 'include/linux/dma-map-ops.h')
| -rw-r--r-- | include/linux/dma-map-ops.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 98ceba6fa848..99cec59dbfcb 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -380,4 +380,57 @@ static inline void debug_dma_dump_mappings(struct device *dev) extern const struct dma_map_ops dma_dummy_ops; +enum pci_p2pdma_map_type { + /* + * PCI_P2PDMA_MAP_UNKNOWN: Used internally for indicating the mapping + * type hasn't been calculated yet. Functions that return this enum + * never return this value. + */ + PCI_P2PDMA_MAP_UNKNOWN = 0, + + /* + * PCI_P2PDMA_MAP_NOT_SUPPORTED: Indicates the transaction will + * traverse the host bridge and the host bridge is not in the + * allowlist. DMA Mapping routines should return an error when + * this is returned. + */ + PCI_P2PDMA_MAP_NOT_SUPPORTED, + + /* + * PCI_P2PDMA_BUS_ADDR: Indicates that two devices can talk to + * each other directly through a PCI switch and the transaction will + * not traverse the host bridge. Such a mapping should program + * the DMA engine with PCI bus addresses. + */ + PCI_P2PDMA_MAP_BUS_ADDR, + + /* + * PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: Indicates two devices can talk + * to each other, but the transaction traverses a host bridge on the + * allowlist. In this case, a normal mapping either with CPU physical + * addresses (in the case of dma-direct) or IOVA addresses (in the + * case of IOMMUs) should be used to program the DMA engine. + */ + PCI_P2PDMA_MAP_THRU_HOST_BRIDGE, +}; + +struct pci_p2pdma_map_state { + struct dev_pagemap *pgmap; + int map; + u64 bus_off; +}; + +#ifdef CONFIG_PCI_P2PDMA +enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg); +#else /* CONFIG_PCI_P2PDMA */ +static inline enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg) +{ + return PCI_P2PDMA_MAP_NOT_SUPPORTED; +} +#endif /* CONFIG_PCI_P2PDMA */ + #endif /* _LINUX_DMA_MAP_OPS_H */ |