Re: [PATCH net-next 3/7] net: devmem: use niov_shift in net_devmem_get_niov_at()

[Mina Almasry]

On Mon, Nov 2, 2026 at 11:14 AM Stanislav Fomichev <sdf.kernel@xxxxxxxxx> wrote:
>
> TX bindings use PAGE_SIZE net_iovs, and the TX lookup hard-codes it.
> Derive the index and offset from binding->niov_shift instead, so TX
> bindings can use larger net_iovs. No functional change, TX bindings are
> still created with PAGE_SHIFT.
>
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxxx>
> ---
>  net/core/devmem.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/net/core/devmem.c b/net/core/devmem.c
> index 32fafbfa1359..6339f221bc82 100644
> --- a/net/core/devmem.c
> +++ b/net/core/devmem.c
> @@ -455,13 +455,15 @@ struct net_iov *
>  net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding,
>                        size_t virt_addr, size_t *off, size_t *size)
>  {
> +       size_t niov_size = 1UL << binding->niov_shift;

I always dreamed of net-iovs can be non-power of 2 and also can vary
in size inside the same binding (no reason why not), but this is
providing excellent value anyway.

Reviewed-by: Mina Almasry <almasrymina@xxxxxxxxxx>

-- 
Thanks,
Mina