Re: [RFC PATCH net-next v1 4/4] net: page_pool: use netmem_t instead of struct page in API

[Yunsheng Lin]

On 2023/12/15 10:11, Shakeel Butt wrote:
> On Thu, Dec 14, 2023 at 08:27:55AM -0800, Mina Almasry wrote:
>> On Thu, Dec 14, 2023 at 4:05 AM Yunsheng Lin <linyunsheng@xxxxxxxxxx> wrote:
>>>
> [...]
>>> I perfer the second one personally, as devmem means that it is not
>>> readable from cpu.
>>
>> From my POV it has to be the first one. We want to abstract the memory
>> type from the drivers as much as possible, not introduce N new memory
>> types and ask the driver to implement new code for each of them
>> separately.

That was my initial thinking too:
https://www.spinics.net/lists/netdev/msg949376.html

But after discussion, it may make more sense to have two sets of API from the
driver's piont of view if we want a complete safe type protection, so that
compiler can check everything statically and devmem driver API have a clear
semantic:
1. devmem is not allowed to be called into mm subsystem.
2. it will not provide a API like page_address().

>>
> 
> Agree with Mina's point. Let's aim to decouple memory types from
> drivers.
> .
>