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linux/include/net/netmem.h

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net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
net: enable driver support for netmem TX Drivers need to make sure not to pass netmem dma-addrs to the dma-mapping API in order to support netmem TX. Add helpers and netmem_dma_*() helpers that enables special handling of netmem dma-addrs that drivers can use. Document in netmem.rst what drivers need to do to support netmem TX. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-7-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:26 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: introduce struct netmem_desc mirroring struct page To simplify struct page, the page pool members of struct page should be moved to other, allowing these members to be removed from struct page. Introduce a network memory descriptor to store the members, struct netmem_desc, and make it union'ed with the existing fields in struct net_iov, allowing to organize the fields of struct net_iov. Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Harry Yoo <harry.yoo@oracle.com> Link: https://patch.msgid.link/20250721021835.63939-2-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 11:18:24 +09:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: add niov->type attribute to distinguish different net_iov types Later patches in the series adds TX net_iovs where there is no pp associated, so we can't rely on niov->pp->mp_ops to tell what is the type of the net_iov. Add a type enum to the net_iov which tells us the net_iov type. Signed-off-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250508004830.4100853-2-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:21 +00:00
netmem: introduce struct netmem_desc mirroring struct page To simplify struct page, the page pool members of struct page should be moved to other, allowing these members to be removed from struct page. Introduce a network memory descriptor to store the members, struct netmem_desc, and make it union'ed with the existing fields in struct net_iov, allowing to organize the fields of struct net_iov. Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Harry Yoo <harry.yoo@oracle.com> Link: https://patch.msgid.link/20250721021835.63939-2-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 11:18:24 +09:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
netmem: remove the pp fields from net_iov Now that the pp fields in net_iov have no users, remove them from net_iov and clean up. Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260224061424.11219-1-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-24 15:14:24 +09:00
mm: introduce a new page type for page pool in page type Currently, the condition 'page->pp_magic == PP_SIGNATURE' is used to determine if a page belongs to a page pool. However, with the planned removal of @pp_magic, we should instead leverage the page_type in struct page, such as PGTY_netpp, for this purpose. Introduce and use the page type APIs e.g. PageNetpp(), __SetPageNetpp(), and __ClearPageNetpp() instead, and remove the existing APIs accessing @pp_magic e.g. page_pool_page_is_pp(), netmem_or_pp_magic(), and netmem_clear_pp_magic(). Plus, add @page_type to struct net_iov at the same offset as struct page so as to use the page_type APIs for struct net_iov as well. While at it, reorder @type and @owner in struct net_iov to avoid a hole and increasing the struct size. This work was inspired by the following link: https://lore.kernel.org/all/582f41c0-2742-4400-9c81-0d46bf4e8314@gmail.com/ While at it, move the sanity check for page pool to on the free path. [byungchul@sk.com: gate the sanity check, per Johannes] Link: https://lkml.kernel.org/r/20260316223113.20097-1-byungchul@sk.com Link: https://lkml.kernel.org/r/20260224051347.19621-1-byungchul@sk.com Co-developed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: David Wei <dw@davidwei.uk> Cc: Dragos Tatulea <dtatulea@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Mark Bloch <mbloch@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Simon Horman <horms@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Taehee Yoo <ap420073@gmail.com> Cc: Tariq Toukan <tariqt@nvidia.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-24 14:13:47 +09:00
netmem: introduce struct netmem_desc mirroring struct page To simplify struct page, the page pool members of struct page should be moved to other, allowing these members to be removed from struct page. Introduce a network memory descriptor to store the members, struct netmem_desc, and make it union'ed with the existing fields in struct net_iov, allowing to organize the fields of struct net_iov. Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Harry Yoo <harry.yoo@oracle.com> Link: https://patch.msgid.link/20250721021835.63939-2-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 11:18:24 +09:00
mm: introduce a new page type for page pool in page type Currently, the condition 'page->pp_magic == PP_SIGNATURE' is used to determine if a page belongs to a page pool. However, with the planned removal of @pp_magic, we should instead leverage the page_type in struct page, such as PGTY_netpp, for this purpose. Introduce and use the page type APIs e.g. PageNetpp(), __SetPageNetpp(), and __ClearPageNetpp() instead, and remove the existing APIs accessing @pp_magic e.g. page_pool_page_is_pp(), netmem_or_pp_magic(), and netmem_clear_pp_magic(). Plus, add @page_type to struct net_iov at the same offset as struct page so as to use the page_type APIs for struct net_iov as well. While at it, reorder @type and @owner in struct net_iov to avoid a hole and increasing the struct size. This work was inspired by the following link: https://lore.kernel.org/all/582f41c0-2742-4400-9c81-0d46bf4e8314@gmail.com/ While at it, move the sanity check for page pool to on the free path. [byungchul@sk.com: gate the sanity check, per Johannes] Link: https://lkml.kernel.org/r/20260316223113.20097-1-byungchul@sk.com Link: https://lkml.kernel.org/r/20260224051347.19621-1-byungchul@sk.com Co-developed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: David Wei <dw@davidwei.uk> Cc: Dragos Tatulea <dtatulea@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Mark Bloch <mbloch@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Simon Horman <horms@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Taehee Yoo <ap420073@gmail.com> Cc: Tariq Toukan <tariqt@nvidia.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-24 14:13:47 +09:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
mm: introduce a new page type for page pool in page type Currently, the condition 'page->pp_magic == PP_SIGNATURE' is used to determine if a page belongs to a page pool. However, with the planned removal of @pp_magic, we should instead leverage the page_type in struct page, such as PGTY_netpp, for this purpose. Introduce and use the page type APIs e.g. PageNetpp(), __SetPageNetpp(), and __ClearPageNetpp() instead, and remove the existing APIs accessing @pp_magic e.g. page_pool_page_is_pp(), netmem_or_pp_magic(), and netmem_clear_pp_magic(). Plus, add @page_type to struct net_iov at the same offset as struct page so as to use the page_type APIs for struct net_iov as well. While at it, reorder @type and @owner in struct net_iov to avoid a hole and increasing the struct size. This work was inspired by the following link: https://lore.kernel.org/all/582f41c0-2742-4400-9c81-0d46bf4e8314@gmail.com/ While at it, move the sanity check for page pool to on the free path. [byungchul@sk.com: gate the sanity check, per Johannes] Link: https://lkml.kernel.org/r/20260316223113.20097-1-byungchul@sk.com Link: https://lkml.kernel.org/r/20260224051347.19621-1-byungchul@sk.com Co-developed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: David Wei <dw@davidwei.uk> Cc: Dragos Tatulea <dtatulea@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Mark Bloch <mbloch@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Simon Horman <horms@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Taehee Yoo <ap420073@gmail.com> Cc: Tariq Toukan <tariqt@nvidia.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-24 14:13:47 +09:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
netmem: fix netmem comments Trivial fix to a couple of outdated netmem comments. No code changes, just more accurately describing current code. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250615203511.591438-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-15 20:35:09 +00:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: use _Generic to cover const casting for page_to_netmem() The current page_to_netmem() doesn't cover const casting resulting in trying to cast const struct page * to const netmem_ref fails. To cover the case, change page_to_netmem() to use macro and _Generic. Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20250702053256.4594-5-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02 14:32:55 +09:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
mm: introduce a new page type for page pool in page type Currently, the condition 'page->pp_magic == PP_SIGNATURE' is used to determine if a page belongs to a page pool. However, with the planned removal of @pp_magic, we should instead leverage the page_type in struct page, such as PGTY_netpp, for this purpose. Introduce and use the page type APIs e.g. PageNetpp(), __SetPageNetpp(), and __ClearPageNetpp() instead, and remove the existing APIs accessing @pp_magic e.g. page_pool_page_is_pp(), netmem_or_pp_magic(), and netmem_clear_pp_magic(). Plus, add @page_type to struct net_iov at the same offset as struct page so as to use the page_type APIs for struct net_iov as well. While at it, reorder @type and @owner in struct net_iov to avoid a hole and increasing the struct size. This work was inspired by the following link: https://lore.kernel.org/all/582f41c0-2742-4400-9c81-0d46bf4e8314@gmail.com/ While at it, move the sanity check for page pool to on the free path. [byungchul@sk.com: gate the sanity check, per Johannes] Link: https://lkml.kernel.org/r/20260316223113.20097-1-byungchul@sk.com Link: https://lkml.kernel.org/r/20260224051347.19621-1-byungchul@sk.com Co-developed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: David Wei <dw@davidwei.uk> Cc: Dragos Tatulea <dtatulea@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Mark Bloch <mbloch@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Simon Horman <horms@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Taehee Yoo <ap420073@gmail.com> Cc: Tariq Toukan <tariqt@nvidia.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-24 14:13:47 +09:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
netmem: use netmem_desc instead of page to access ->pp in __netmem_get_pp() To eliminate the use of the page pool fields in struct page, the page pool code should use netmem descriptor and APIs instead. However, __netmem_get_pp() still accesses ->pp via struct page. So change it to use struct netmem_desc instead, since ->pp no longer will be available in struct page. While at it, add a helper, __netmem_to_nmdesc(), that can be used to unsafely get pointer to netmem_desc backing the netmem_ref, only when the netmem_ref is always backed by system memory. Signed-off-by: Byungchul Park <byungchul@sk.com> Link: https://patch.msgid.link/20250721021835.63939-3-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 11:18:25 +09:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
netmem: fix netmem comments Trivial fix to a couple of outdated netmem comments. No code changes, just more accurately describing current code. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250615203511.591438-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-15 20:35:09 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
netmem: fix netmem comments Trivial fix to a couple of outdated netmem comments. No code changes, just more accurately describing current code. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250615203511.591438-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-15 20:35:09 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
netmem: fix netmem comments Trivial fix to a couple of outdated netmem comments. No code changes, just more accurately describing current code. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250615203511.591438-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-15 20:35:09 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
netmem: use netmem_desc instead of page to access ->pp in __netmem_get_pp() To eliminate the use of the page pool fields in struct page, the page pool code should use netmem descriptor and APIs instead. However, __netmem_get_pp() still accesses ->pp via struct page. So change it to use struct netmem_desc instead, since ->pp no longer will be available in struct page. While at it, add a helper, __netmem_to_nmdesc(), that can be used to unsafely get pointer to netmem_desc backing the netmem_ref, only when the netmem_ref is always backed by system memory. Signed-off-by: Byungchul Park <byungchul@sk.com> Link: https://patch.msgid.link/20250721021835.63939-3-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 11:18:25 +09:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
page_pool: convert to use netmem Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28 00:32:42 +00:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: add a couple of page helper wrappers Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-03 18:37:30 +01:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
netmem: replace __netmem_clear_lsb() with netmem_to_nmdesc() Now that we have struct netmem_desc, it'd better access the pp fields via struct netmem_desc rather than struct net_iov. Introduce netmem_to_nmdesc() for safely converting netmem_ref to netmem_desc regardless of the type underneath e.i. netmem_desc, net_iov. While at it, remove __netmem_clear_lsb() and make netmem_to_nmdesc() used instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Byungchul Park <byungchul@sk.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20251013044133.69472-1-byungchul@sk.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13 13:41:33 +09:00
page_pool: devmem support Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:49 +00:00
net: inline net_is_devmem_iov() 1) Inline this small helper to reduce code size and decrease cpu costs. 2) Constify its argument. 3) Move it to include/net/netmem.h, as a prereq for the following patch. $ scripts/bloat-o-meter -t vmlinux.2 vmlinux.3 add/remove: 0/2 grow/shrink: 0/4 up/down: 0/-158 (-158) Function old new delta validate_xmit_skb 866 857 -9 __pfx_net_is_devmem_iov 16 - -16 net_is_devmem_iov 22 - -22 get_netmem 152 130 -22 put_netmem 140 114 -26 tcp_recvmsg_locked 3860 3797 -63 Total: Before=22566015, After=22565857, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260122045720.1221017-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-22 04:57:18 +00:00
net: inline get_netmem() and put_netmem() These helpers are used in network fast paths. Only call out-of-line helpers for netmem case. We might consider inlining __get_netmem() and __put_netmem() in the future. $ scripts/bloat-o-meter -t vmlinux.3 vmlinux.4 add/remove: 6/6 grow/shrink: 22/1 up/down: 2614/-646 (1968) Function old new delta pskb_carve 1669 1894 +225 gro_pull_from_frag0 - 206 +206 get_page 190 380 +190 skb_segment 3561 3747 +186 put_page 595 765 +170 skb_copy_ubufs 1683 1822 +139 __pskb_trim_head 276 401 +125 __pskb_copy_fclone 734 858 +124 skb_zerocopy 1092 1215 +123 pskb_expand_head 892 1008 +116 skb_split 828 940 +112 skb_release_data 297 409 +112 ___pskb_trim 829 941 +112 __skb_zcopy_downgrade_managed 120 226 +106 tcp_clone_payload 530 634 +104 esp_ssg_unref 191 294 +103 dev_gro_receive 1464 1514 +50 __put_netmem - 41 +41 __get_netmem - 41 +41 skb_shift 1139 1175 +36 skb_try_coalesce 681 714 +33 __pfx_put_page 112 144 +32 __pfx_get_page 32 64 +32 __pskb_pull_tail 1137 1168 +31 veth_xdp_get 250 267 +17 __pfx_gro_pull_from_frag0 - 16 +16 __pfx___put_netmem - 16 +16 __pfx___get_netmem - 16 +16 __pfx_put_netmem 16 - -16 __pfx_gro_try_pull_from_frag0 16 - -16 __pfx_get_netmem 16 - -16 put_netmem 114 - -114 get_netmem 130 - -130 napi_gro_frags 929 771 -158 gro_try_pull_from_frag0 196 - -196 Total: Before=22565857, After=22567825, chg +0.01% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260122045720.1221017-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-22 04:57:19 +00:00
net: add get_netmem/put_netmem support Currently net_iovs support only pp ref counts, and do not support a page ref equivalent. This is fine for the RX path as net_iovs are used exclusively with the pp and only pp refcounting is needed there. The TX path however does not use pp ref counts, thus, support for get_page/put_page equivalent is needed for netmem. Support get_netmem/put_netmem. Check the type of the netmem before passing it to page or net_iov specific code to obtain a page ref equivalent. For dmabuf net_iovs, we obtain a ref on the underlying binding. This ensures the entire binding doesn't disappear until all the net_iovs have been put_netmem'ed. We do not need to track the refcount of individual dmabuf net_iovs as we don't allocate/free them from a pool similar to what the buddy allocator does for pages. This code is written to be extensible by other net_iov implementers. get_netmem/put_netmem will check the type of the netmem and route it to the correct helper: pages -> [get|put]_page() dmabuf net_iovs -> net_devmem_[get|put]_net_iov() new net_iovs -> new helpers Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-3-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:22 +00:00
net: enable driver support for netmem TX Drivers need to make sure not to pass netmem dma-addrs to the dma-mapping API in order to support netmem TX. Add helpers and netmem_dma_*() helpers that enables special handling of netmem dma-addrs that drivers can use. Document in netmem.rst what drivers need to do to support netmem TX. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-7-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:26 +00:00
net: introduce abstraction for network memory Add the netmem_ref type, an abstraction for network memory. To add support for new memory types to the net stack, we must first abstract the current memory type. Currently parts of the net stack use struct page directly: - page_pool - drivers - skb_frag_t Originally the plan was to reuse struct page* for the new memory types, and to set the LSB on the page* to indicate it's not really a page. However, for compiler type checking we need to introduce a new type. netmem_ref is introduced to abstract the underlying memory type. Currently it's a no-op abstraction that is always a struct page underneath. In parallel there is an undergoing effort to add support for devmem to the net stack: https://lore.kernel.org/netdev/20231208005250.2910004-1-almasrymina@google.com/ netmem_ref can be pointers to different underlying memory types, and the low bits are set to indicate the memory type. Helpers are provided to convert netmem pointers to the underlying memory type (currently only struct page). In the devmem series helpers are provided so that calling code can use netmem without worrying about the underlying memory type unless absolutely necessary. Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-14 14:34:02 -08:00