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dma-buf: heaps: Set VM_PFNMAP in mmap for system and cma heaps

Message ID 20210226040908.3274666-1-john.stultz@linaro.org
State New
Headers show
Series dma-buf: heaps: Set VM_PFNMAP in mmap for system and cma heaps | expand

Commit Message

John Stultz Feb. 26, 2021, 4:09 a.m. UTC
Per discussion and patches here:
  https://lore.kernel.org/dri-devel/20210223105951.912577-1-daniel.vetter@ffwll.ch/

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 <daniel@ffwll.ch>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Ørjan Eide <orjan.eide@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Ezequiel Garcia <ezequiel@collabora.com>
Cc: Simon Ser <contact@emersion.fr>
Cc: James Jones <jajones@nvidia.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/dma-buf/heaps/cma_heap.c    | 1 +
 drivers/dma-buf/heaps/system_heap.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

Comments

'Christoph Hellwig' Feb. 27, 2021, 9:44 a.m. UTC | #1
On Fri, Feb 26, 2021 at 08:36:55AM +0100, Daniel Vetter wrote:
> 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.

I've been saying that since the code was first submitted.  Once pages
are allocated from CMA they should be treated not different from normal
pages.

Please take a look at how the DMA contigous allocator manages to share
all code for handling CMA vs alloc_pages pages.
John Stultz March 2, 2021, 2:51 a.m. UTC | #2
On Sat, Feb 27, 2021 at 1:44 AM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Fri, Feb 26, 2021 at 08:36:55AM +0100, Daniel Vetter wrote:
> > 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.
>
> I've been saying that since the code was first submitted.  Once pages
> are allocated from CMA they should be treated not different from normal
> pages.
>
> Please take a look at how the DMA contigous allocator manages to share
> all code for handling CMA vs alloc_pages pages.

I'll take a look at that! Thanks for the pointer!
-john
diff mbox series

Patch

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;
 }