Re: [RFC PATCH net-next v5 05/14] netdev: netdevice devmem allocator

Pavel Begunkov
2024-02-13T13:24:53Z

On 12/18/23 02:40, Mina Almasry wrote:
> Implement netdev devmem allocator. The allocator takes a given struct
> netdev_dmabuf_binding as input and allocates net_iov from that
> binding.
>
> The allocation simply delegates to the binding's genpool for the
> allocation logic and wraps the returned memory region in a net_iov
> struct.
>
> 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>
>
> ---
>
> v1:
> - Rename devmem -> dmabuf (David).
>
> ---
> include/net/devmem.h | 12 ++++++++++++
> include/net/netmem.h | 26 ++++++++++++++++++++++++++
> net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 76 insertions(+)
>
...
> diff --git a/include/net/netmem.h b/include/net/netmem.h
> index 45eb42d9990b..7fce2efc8707 100644
> --- a/include/net/netmem.h
> +++ b/include/net/netmem.h
> @@ -14,8 +14,34 @@
>
> struct net_iov {
> struct dmabuf_genpool_chunk_owner *owner;
> + unsigned long dma_addr;
> };
>
> +static inline struct dmabuf_genpool_chunk_owner *
> +net_iov_owner(const struct net_iov *niov)
> +{
> + return niov->owner;
> +}
> +
> +static inline unsigned int net_iov_idx(const struct net_iov *niov)
> +{
> + return niov - net_iov_owner(niov)->niovs;
> +}
> +
> +static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
> +{
> + struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
> +
> + return owner->base_dma_addr +
> + ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);

Looks like it should have been niov->dma_addr

> +}
> +
> +static inline struct netdev_dmabuf_binding *
> +net_iov_binding(const struct net_iov *niov)
> +{
> + return net_iov_owner(niov)->binding;
> +}
> +
> /* netmem */
>
> struct netmem {
...

--
Pavel Begunkov