diff options
Diffstat (limited to 'include/linux/pci-p2pdma.h')
| -rw-r--r-- | include/linux/pci-p2pdma.h | 131 |
1 files changed, 105 insertions, 26 deletions
diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h index 8318a97c9c61..517e121d2598 100644 --- a/include/linux/pci-p2pdma.h +++ b/include/linux/pci-p2pdma.h @@ -16,12 +16,62 @@ struct block_device; struct scatterlist; +/** + * struct p2pdma_provider + * + * A p2pdma provider is a range of MMIO address space available to the CPU. + */ +struct p2pdma_provider { + struct device *owner; + u64 bus_offset; +}; + +enum pci_p2pdma_map_type { + /* + * PCI_P2PDMA_MAP_UNKNOWN: Used internally as an initial state before + * the mapping type has been calculated. Exported routines for the API + * will never return this value. + */ + PCI_P2PDMA_MAP_UNKNOWN = 0, + + /* + * Not a PCI P2PDMA transfer. + */ + PCI_P2PDMA_MAP_NONE, + + /* + * 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_MAP_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, +}; + #ifdef CONFIG_PCI_P2PDMA +int pcim_p2pdma_init(struct pci_dev *pdev); +struct p2pdma_provider *pcim_p2pdma_provider(struct pci_dev *pdev, int bar); int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, u64 offset); int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients, int num_clients, bool verbose); -bool pci_has_p2pmem(struct pci_dev *pdev); struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients); void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size); void pci_free_p2pmem(struct pci_dev *pdev, void *addr, size_t size); @@ -30,15 +80,22 @@ struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev, unsigned int *nents, u32 length); void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl); void pci_p2pmem_publish(struct pci_dev *pdev, bool publish); -int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg, - int nents, enum dma_data_direction dir, unsigned long attrs); -void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, - int nents, enum dma_data_direction dir, unsigned long attrs); int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, bool *use_p2pdma); ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, bool use_p2pdma); +enum pci_p2pdma_map_type pci_p2pdma_map_type(struct p2pdma_provider *provider, + struct device *dev); #else /* CONFIG_PCI_P2PDMA */ +static inline int pcim_p2pdma_init(struct pci_dev *pdev) +{ + return -EOPNOTSUPP; +} +static inline struct p2pdma_provider *pcim_p2pdma_provider(struct pci_dev *pdev, + int bar) +{ + return NULL; +} static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, u64 offset) { @@ -49,10 +106,6 @@ static inline int pci_p2pdma_distance_many(struct pci_dev *provider, { return -1; } -static inline bool pci_has_p2pmem(struct pci_dev *pdev) -{ - return false; -} static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients) { @@ -83,17 +136,6 @@ static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev, static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) { } -static inline int pci_p2pdma_map_sg_attrs(struct device *dev, - struct scatterlist *sg, int nents, enum dma_data_direction dir, - unsigned long attrs) -{ - return 0; -} -static inline void pci_p2pdma_unmap_sg_attrs(struct device *dev, - struct scatterlist *sg, int nents, enum dma_data_direction dir, - unsigned long attrs) -{ -} static inline int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, bool *use_p2pdma) { @@ -105,6 +147,11 @@ static inline ssize_t pci_p2pdma_enable_show(char *page, { return sprintf(page, "none\n"); } +static inline enum pci_p2pdma_map_type +pci_p2pdma_map_type(struct p2pdma_provider *provider, struct device *dev) +{ + return PCI_P2PDMA_MAP_NOT_SUPPORTED; +} #endif /* CONFIG_PCI_P2PDMA */ @@ -119,16 +166,48 @@ static inline struct pci_dev *pci_p2pmem_find(struct device *client) return pci_p2pmem_find_many(&client, 1); } -static inline int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, - int nents, enum dma_data_direction dir) +struct pci_p2pdma_map_state { + struct p2pdma_provider *mem; + enum pci_p2pdma_map_type map; +}; + + +/* helper for pci_p2pdma_state(), do not use directly */ +void __pci_p2pdma_update_state(struct pci_p2pdma_map_state *state, + struct device *dev, struct page *page); + +/** + * pci_p2pdma_state - check the P2P transfer state of a page + * @state: P2P state structure + * @dev: device to transfer to/from + * @page: page to map + * + * Check if @page is a PCI P2PDMA page, and if yes of what kind. Returns the + * map type, and updates @state with all information needed for a P2P transfer. + */ +static inline enum pci_p2pdma_map_type +pci_p2pdma_state(struct pci_p2pdma_map_state *state, struct device *dev, + struct page *page) { - return pci_p2pdma_map_sg_attrs(dev, sg, nents, dir, 0); + if (IS_ENABLED(CONFIG_PCI_P2PDMA) && is_pci_p2pdma_page(page)) { + __pci_p2pdma_update_state(state, dev, page); + return state->map; + } + return PCI_P2PDMA_MAP_NONE; } -static inline void pci_p2pdma_unmap_sg(struct device *dev, - struct scatterlist *sg, int nents, enum dma_data_direction dir) +/** + * pci_p2pdma_bus_addr_map - Translate a physical address to a bus address + * for a PCI_P2PDMA_MAP_BUS_ADDR transfer. + * @provider: P2P provider structure + * @paddr: physical address to map + * + * Map a physically contiguous PCI_P2PDMA_MAP_BUS_ADDR transfer. + */ +static inline dma_addr_t +pci_p2pdma_bus_addr_map(struct p2pdma_provider *provider, phys_addr_t paddr) { - pci_p2pdma_unmap_sg_attrs(dev, sg, nents, dir, 0); + return paddr + provider->bus_offset; } #endif /* _LINUX_PCI_P2P_H */ |