Re: [PATCH net-next] eth: bnxt: add support rx side device memory TCP

[Jakub Kicinski <kuba@kernel.org>]

On Tue,  8 Apr 2025 04:35:45 +0000 Taehee Yoo wrote:
> Currently, bnxt_en driver satisfies the requirements of the Device
> memory TCP, which is HDS.
> So, it implements rx-side Device memory TCP for bnxt_en driver.
> It requires only converting the page API to netmem API.
> `struct page` of agg rings are changed to `netmem_ref netmem` and
> corresponding functions are changed to a variant of netmem API.
> 
> It also passes PP_FLAG_ALLOW_UNREADABLE_NETMEM flag to a parameter of
> page_pool.
> The netmem will be activated only when a user requests devmem TCP.
> 
> When netmem is activated, received data is unreadable and netmem is
> disabled, received data is readable.
> But drivers don't need to handle both cases because netmem core API will
> handle it properly.
> So, using proper netmem API is enough for drivers.
> 
> Device memory TCP can be tested with
> tools/testing/selftests/drivers/net/hw/ncdevmem.
> This is tested with BCM57504-N425G and firmware version 232.0.155.8/pkg
> 232.1.132.8.

drivers/net/ethernet/broadcom/bnxt/bnxt.c:1262:14: warning: variable 'mapping' set but not used [-Wunused-but-set-variable]
 1262 |                 dma_addr_t mapping;
      |                            ^
-- 
pw-bot: cr