Re: [net-next PATCH v2 09/15] eth: fbnic: Implement Rx queue alloc/start/stop/free

[Simon Horman <horms@kernel.org>]

On Tue, Jun 25, 2024 at 07:36:10AM -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexanderduyck@fb.com>
> 
> Implement control path parts of Rx queue handling.
> 
> The NIC consumes memory in pages. It takes a full page and places
> packets into it in a configurable manner (with the ability to define
> headroom / tailroom as well as head alignment requirements).
> As mentioned in prior patches there are two page submissions queues
> one for packet headers and second (optional) for packet payloads.
> For now feed both queues from a single page pool.
> 
> Use the page pool "fragment" API, as we can't predict upfront
> how the page will be sliced.
> 
> Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
> ---
>  drivers/net/ethernet/meta/fbnic/fbnic_csr.h    |  103 +++++
>  drivers/net/ethernet/meta/fbnic/fbnic_netdev.c |    3 
>  drivers/net/ethernet/meta/fbnic/fbnic_netdev.h |    3 
>  drivers/net/ethernet/meta/fbnic/fbnic_pci.c    |    2 
>  drivers/net/ethernet/meta/fbnic/fbnic_txrx.c   |  480 ++++++++++++++++++++++++
>  drivers/net/ethernet/meta/fbnic/fbnic_txrx.h   |   33 ++
>  6 files changed, 615 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
> index db423b3424ab..853fb01f8f70 100644
> --- a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
> +++ b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
> @@ -16,6 +16,37 @@
>  
>  #define FBNIC_CLOCK_FREQ	(600 * (1000 * 1000))
>  
> +/* Rx Buffer Descriptor Format
> + *
> + * The layout of this can vary depending on the page size of the system.
> + *
> + * If the page size is 4K then the layout will simply consist of ID for
> + * the 16 most signficant bits, and the lower 46 are essentially the page

nit: significant

...