On Mon, Jan 09, 2023 at 07:30:30PM +0200, Ilias Apalodimas wrote: > Hi Matthew Hey Ilias. Thanks for all the review! > > -static inline dma_addr_t page_pool_get_dma_addr(struct page *page) > > +static inline dma_addr_t netmem_get_dma_addr(struct netmem *nmem) > > Ideally, we'd like to avoid having people call these directly and use > the page_pool_(get|set)_dma_addr wrappers. Can we add a comment in > v3? I don't think this is what we want. Currently drivers call page_pool_get_dma_addr() on pages that are presumably from the page pool, but the compiler isn't going to help them out if they just get the struct page from somewhere random. They'll get garbage and presumably crash. By returning a netmem pointer from page_pool, we help drivers ensure that they're only passing around memory that was actually allocated from the page_pool and so they won't get garbage if they pass it to netmem_get_dma_addr(). The page_pool_get_dma_addr() wrapper is a temporary measure until we have all the drivers converted to use netmem alone. Does that all make sense, or have I misunderstood what you wanted from a comment?
