On Fri, Feb 26, 2021 at 5:09 AM John Stultz <[email protected]> wrote: > > Per discussion and patches here: > > https://lore.kernel.org/dri-devel/[email protected]/ > > Daniel is planning on making VM_PFNMAP required on dmabufs. > > Thus to avoid the warn_on noise, set the VM_PFNMAP in the > system and cma heap's mmap handler. > > Cc: Daniel Vetter <[email protected]> > Cc: Jason Gunthorpe <[email protected]> > Cc: Christian Koenig <[email protected]> > Cc: Sumit Semwal <[email protected]> > Cc: Liam Mark <[email protected]> > Cc: Chris Goldsworthy <[email protected]> > Cc: Laura Abbott <[email protected]> > Cc: Brian Starkey <[email protected]> > Cc: Hridya Valsaraju <[email protected]> > Cc: Suren Baghdasaryan <[email protected]> > Cc: Sandeep Patil <[email protected]> > Cc: Daniel Mentz <[email protected]> > Cc: Ørjan Eide <[email protected]> > Cc: Robin Murphy <[email protected]> > Cc: Ezequiel Garcia <[email protected]> > Cc: Simon Ser <[email protected]> > Cc: James Jones <[email protected]> > Cc: [email protected] > Cc: [email protected] > Signed-off-by: John Stultz <[email protected]>
System heap uses remap_pfn_range so looks fine, but cma heap inserts pages, and that's not fine for VM_PFNMAP. You need to use vm_insert_pfn or remap_pfn_range or one of the related pfn mapping functions for that too. I think this should splat when you run it. Also note that remap_pfn_range updates the vma flags already correctly for you, so you probably don't want to do that. Also given that both deal with struct page there's a ton of divergence between these two that doesn't make much sense. Maybe could even share the code fully, aside from how you allocate the struct pages. -Daniel > --- > drivers/dma-buf/heaps/cma_heap.c | 1 + > drivers/dma-buf/heaps/system_heap.c | 4 +++- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma-buf/heaps/cma_heap.c > b/drivers/dma-buf/heaps/cma_heap.c > index 364fc2f3e499..34bc3987f942 100644 > --- a/drivers/dma-buf/heaps/cma_heap.c > +++ b/drivers/dma-buf/heaps/cma_heap.c > @@ -185,6 +185,7 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct > vm_area_struct *vma) > > vma->vm_ops = &dma_heap_vm_ops; > vma->vm_private_data = buffer; > + vma->vm_flags |= VM_PFNMAP; > > return 0; > } > diff --git a/drivers/dma-buf/heaps/system_heap.c > b/drivers/dma-buf/heaps/system_heap.c > index 3548b20cb98c..8995e3cbfcaf 100644 > --- a/drivers/dma-buf/heaps/system_heap.c > +++ b/drivers/dma-buf/heaps/system_heap.c > @@ -228,8 +228,10 @@ static int system_heap_mmap(struct dma_buf *dmabuf, > struct vm_area_struct *vma) > return ret; > addr += PAGE_SIZE; > if (addr >= vma->vm_end) > - return 0; > + break; > } > + > + vma->vm_flags |= VM_PFNMAP; > return 0; > } > > -- > 2.25.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
