On 12/16/23 2:10 PM, Mina Almasry wrote:
> On Fri, Dec 15, 2023 at 6:52 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>>
>> On Wed, 13 Dec 2023 18:05:25 -0800 Mina Almasry wrote:
>>> +struct netmem {
>>> + union {
>>> + struct page page;
>>> +
>>> + /* Stub to prevent compiler implicitly converting from page*
>>> + * to netmem_t* and vice versa.
>>> + *
>>> + * Other memory type(s) net stack would like to support
>>> + * can be added to this union.
>>> + */
>>> + void *addr;
>>> + };
>>> +};
>>
>> My mind went to something like:
>>
>> typedef unsigned long __bitwise netmem_ref;
>>
>> instead. struct netmem does not exist, it's a handle which has
>> to be converted to a real type using a helper.
>
> Sure thing I can do that. Is it better to do something like:
>
> struct netmem_ref;
>
> like in this patch:
>
> https://lore.kernel.org/linux-mm/20221108194139.57604-1-torvalds@xxxxxxxxxxxxxxxxxxxx/
>
> Asking because checkpatch tells me not to add typedefs to the kernel,
> but checkpatch can be ignored if you think it's OK.
>
> Also with this approach I can't use container_of and I need to do a
> cast, I assume that's fine.
>
Isn't that the whole point of this set - to introduce a new data type
and avoid casts?
