[dpdk-dev] [PATCH 4/4] net/sfc: support regioned NIC DMA memory mapping type

[Thomas Monjalon]

06/11/2021 09:39, Andrew Rybchenko:
> On 11/5/21 11:14 PM, Thomas Monjalon wrote:
> > 05/11/2021 20:05, Ferruh Yigit:
> >> On 11/5/2021 8:33 AM, Andrew Rybchenko wrote:
> >>> From: Viacheslav Galaktionov <viacheslav.galaktionov at oktetlabs.ru>
> >>>
> >>> DMA on SN1022 SoC requires extra mapping of the memory via MCDI.
> >>> The mapping is expensive on datapath, so make it a build-time option.
> >>> Usage of build-time option is acceptable since it is required in
> >>> very specific case only.
> >>>
> >>
> >> Not really sure if it is acceptable.
> >>
> >> The change does not look trivial, it touches in many areas with ifdef blocks,
> >> cluttering the code.
> >>
> >> Even it is in datapath, it should be possible to have another datapath
> >> function that is only set for the specific device, even perhaps by automatically
> >> detecting the device, not needing a compile or runtime flag.
> > 
> > Indeed compilation option is forbidden.
> > Function pointer is a better choice.
> 
> Thanks for the feedback. Unfortunately expected.

Ideally the values in drivers/net/sfc/sfc_tweak.h should be configurable
at runtime with devargs options.