diff options
| author | Leon Romanovsky <leonro@nvidia.com> | 2025-11-20 11:28:23 +0200 |
|---|---|---|
| committer | Alex Williamson <alex@shazbot.org> | 2025-11-20 12:02:00 -0700 |
| commit | 395698bd2cd7639b85784a4a8f5ddb7a581e353c (patch) | |
| tree | 87fd01a56ca21ab56fe491df32005961faf3ae77 /drivers/pci | |
| parent | 372d6d1b8ae3cdfe6b0638a0a848c6865ec94567 (diff) | |
PCI/P2PDMA: Provide an access to pci_p2pdma_map_type() function
Provide an access to pci_p2pdma_map_type() function to allow subsystems
to determine the appropriate mapping type for P2PDMA transfers between
a provider and target device.
The pci_p2pdma_map_type() function is the core P2P layer version of
the existing public, but struct page focused, pci_p2pdma_state()
function. It returns the same result. It is required to use the p2p
subsystem from drivers that don't use the struct page layer.
Like __pci_p2pdma_update_state() it is not an exported function. The
idea is that only subsystem code will implement mapping helpers for
taking in phys_addr_t lists, this is deliberately not made accessible
to every driver to prevent abuse.
Following patches will use this function to implement a shared DMA
mapping helper for DMABUF.
Tested-by: Alex Mastro <amastro@fb.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20251120-dmabuf-vfio-v9-4-d7f71607f371@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/p2pdma.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 855d3493634c..981a76b6b7c0 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -1060,8 +1060,18 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) } EXPORT_SYMBOL_GPL(pci_p2pmem_publish); -static enum pci_p2pdma_map_type -pci_p2pdma_map_type(struct p2pdma_provider *provider, struct device *dev) +/** + * pci_p2pdma_map_type - Determine the mapping type for P2PDMA transfers + * @provider: P2PDMA provider structure + * @dev: Target device for the transfer + * + * Determines how peer-to-peer DMA transfers should be mapped between + * the provider and the target device. The mapping type indicates whether + * the transfer can be done directly through PCI switches or must go + * through the host bridge. + */ +enum pci_p2pdma_map_type pci_p2pdma_map_type(struct p2pdma_provider *provider, + struct device *dev) { enum pci_p2pdma_map_type type = PCI_P2PDMA_MAP_NOT_SUPPORTED; struct pci_dev *pdev = to_pci_dev(provider->owner); |