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PCI/P2PDMA: Update DMABUF lifecycle docs after move_notify() rename

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Commit 95308225e5 ("dma-buf: Rename dma_buf_move_notify() to
dma_buf_invalidate_mappings()") left the DMABUF section of the P2PDMA
documentation pointing at move_notify(), a symbol that no longer exists.
Readers grepping for it find nothing, and this is the only place in
Documentation/ describing the revocation requirement.

Name the current function and record that importers which cannot unmap
within bounded time have to be rejected at attach time, which is what makes
the synchronous unmap on remove() achievable.

Fixes: 95308225e5 ("dma-buf: Rename dma_buf_move_notify() to dma_buf_invalidate_mappings()")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://patch.msgid.link/20260830-doc-p2p-move-v1-1-61a388620588@nvidia.com
This commit is contained in:
Leon Romanovsky 2026-08-30 15:31:49 +03:00 committed by Bjorn Helgaas
parent e7b44579a6
commit 1319b08586
1 changed files with 4 additions and 2 deletions
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6
Documentation/driver-api/pci/p2pdma.rst
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@ -167,9 +167,11 @@ In this case the initiator and target pci_devices are known and the P2P subsyste
is used to determine the mapping type. The phys_addr_t-based DMA API is used to
establish the dma_addr_t.
Lifecycle is controlled by DMABUF move_notify(). When the exporting driver wants
Lifecycle is controlled by DMABUF revocation. When the exporting driver wants
to remove() it must deliver an invalidation shutdown to all DMABUF importing
drivers through move_notify() and synchronously DMA unmap all the MMIO.
drivers through dma_buf_invalidate_mappings() and synchronously DMA unmap all
the MMIO. Importers unable to complete that unmap within bounded time have to
be rejected when they attach, which dma_buf_attach_revocable() checks for.
No importing driver can continue to have a DMA map to the MMIO after the
exporting driver has destroyed its p2p_provider.