Re: [PATCH net-next v3 00/12] bnxt_en: Add XDP support.

[David Miller <davem@davemloft.net>]

From: Michael Chan <michael.chan@broadcom.com>
Date: Mon,  6 Feb 2017 16:55:31 -0500

> The first 10 patches refactor the code (rx/tx code paths and ring logic)
> and add the basic infrastructure to support XDP.  The 11th patch adds
> basic ndo_xdp to support XDP_DROP and XDP_PASS only.  The 12th patch
> completes the series with XDP_TX.
> 
> Thanks to Andy Gospodarek for testing and uncovering some bugs.
> 
> v3: Removed Kconfig option.
>     Pass modified offset and length to stack for XDP_PASS.
>     Improved buffer recycling scheme for XDP_TX.
>     Other minor fixes.
> 
> v2: Addressed review comments from Alexei Starovoitov, Jakub Kicinski,
> and David Miller:
> 	- Added missing dma syncs.
> 	- Added XDP headroom support.
> 	- Added tracing in exception path.
> 	- Clarified a parameter change.

Series applied, thanks Michael.

You can probably push the XDP program existance check into an inline
helper to avoid the function call when XDP isn't being used:

bool __bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
		   struct page *page, u8 **data_ptr, unsigned int *len, u8 *event,
		   struct bpf_prog *xdp_prog);

static inline bool __bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
		                 struct page *page, u8 **data_ptr, unsigned int *len, u8 *event)
{
	struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);

	if (!xdp_prog)
		return false;
	return bnxt_rx_xdp(bp, rxr, cons, page, data_ptr, len, event, xdp_prog);
}