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Diffstat (limited to 'Documentation/networking/netmem.rst')
| -rw-r--r-- | Documentation/networking/netmem.rst | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/Documentation/networking/netmem.rst b/Documentation/networking/netmem.rst index 7de21ddb5412..b63aded46337 100644 --- a/Documentation/networking/netmem.rst +++ b/Documentation/networking/netmem.rst @@ -19,8 +19,8 @@ Benefits of Netmem : * Simplified Development: Drivers interact with a consistent API, regardless of the underlying memory implementation. -Driver Requirements -=================== +Driver RX Requirements +====================== 1. The driver must support page_pool. @@ -77,3 +77,22 @@ Driver Requirements that purpose, but be mindful that some netmem types might have longer circulation times, such as when userspace holds a reference in zerocopy scenarios. + +Driver TX Requirements +====================== + +1. The Driver must not pass the netmem dma_addr to any of the dma-mapping APIs + directly. This is because netmem dma_addrs may come from a source like + dma-buf that is not compatible with the dma-mapping APIs. + + Helpers like netmem_dma_unmap_page_attrs() & netmem_dma_unmap_addr_set() + should be used in lieu of dma_unmap_page[_attrs](), dma_unmap_addr_set(). + The netmem variants will handle netmem dma_addrs correctly regardless of the + source, delegating to the dma-mapping APIs when appropriate. + + Not all dma-mapping APIs have netmem equivalents at the moment. If your + driver relies on a missing netmem API, feel free to add and propose to + netdev@, or reach out to the maintainers and/or almasrymina@google.com for + help adding the netmem API. + +2. Driver should declare support by setting `netdev->netmem_tx = true` |