Messages in this thread | | | Subject | Re: [PATCH 12/21] dma-iommu: factor atomic pool allocations into helpers | From | Robin Murphy <> | Date | Thu, 18 Apr 2019 19:15:00 +0100 |
| |
On 18/04/2019 17:35, Christoph Hellwig wrote: > On Thu, Apr 18, 2019 at 04:06:56PM +0100, Robin Murphy wrote: >> OK, I'm still looking at mmap and get_sgtable, but for now I've pushed out >> a partial branch that consolidates alloc and free in a way which makes >> sense to me: >> >> git://linux-arm.org/linux-rm dma/rework >> >> Please let me know what you think. > > From a very high level POV this looks ok, but sometimes a bit to > convoluted to me. The major issue why I went with the version I posted > is that I can cleanly ifdef out the remap code in just a few sections. > In this version it is spread out a lot more, and the use of IS_ENABLED > means that we'd need a lot more stubs for functionality that won't > ever be called but needs to be compilable.
OK, for some reason I'd convinced myself that mmap and get_sgtable would need changes to properly handle the new non-remapped CMA case - not sure how I reached that conclusion. On inspection they do appear to be broken for the non-coherent atomic case, but AFAICS that's been so forever...
Still, I've worked in the vm_map_pages() stuff pending in MM and given them the same treatment to finish the picture. Both x86_64_defconfig and i386_defconfig do indeed compile and link fine as I expected, so I really would like to understand the concern around #ifdefs better.
Robin.
| |