Re: [RFC PATCH v2 0/3] prerequisites for device reserved local mem rework

From: hch@xxxxxx
Date: Tue May 21 2019 - 06:35:09 EST


On Mon, May 20, 2019 at 05:41:56PM +0200, Fredrik Noring wrote:
> 2. A device address is supplied as phys_addr_t phys to gen_pool_add_virt().
> This seems to work in this particular DMA application, but there will be
> problems if someone does phys_to_virt() or suchlike. Can this be improved
> or clearly explained? gen_pool_virt_to_phys() searches in address ranges,
> for example, so it appears the implementation uses phys quite carefully.

Well, it is a physical address, but not one that has a kernel mapping.
So phys_addr_t seems right here, but an additional comment explaining it
is not in the kernel mapping never hurts.