include/linux/pci-p2pdma.h

Source file repositories/reference/linux-study-clean/include/linux/pci-p2pdma.h

File Facts

System
Linux kernel
Corpus path
include/linux/pci-p2pdma.h
Extension
.h
Size
6360 bytes
Lines
216
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

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);
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);
pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev, void *addr);
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_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)
{
	return -EOPNOTSUPP;
}
static inline int pci_p2pdma_distance_many(struct pci_dev *provider,
	struct device **clients, int num_clients, bool verbose)
{
	return -1;
}
static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients,
						   int num_clients)
{
	return NULL;
}

Annotation

Implementation Notes