Add trivial implementation for arch_dma_coherent_to_pfn.
This change enables communication with PCI ALSA devices through mmapped
buffers.
Signed-off-by: Max Filippov <[email protected]>
---
arch/xtensa/Kconfig | 1 +
arch/xtensa/kernel/pci-dma.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index bf492f9e1f75..f78e6b6f8b6f 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config XTENSA
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_HAS_BINFMT_FLAT if !MMU
+ select ARCH_HAS_DMA_COHERENT_TO_PFN
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_USE_QUEUED_RWLOCKS
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 154979d62b73..6a114ce23084 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -200,3 +200,9 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
+
+long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
+ dma_addr_t dma_addr)
+{
+ return __phys_to_pfn(dma_to_phys(dev, dma_addr));
+}
--
2.20.1
On Tue, Oct 15, 2019 at 02:25:26PM -0700, Max Filippov wrote:
> Add trivial implementation for arch_dma_coherent_to_pfn.
> This change enables communication with PCI ALSA devices through mmapped
> buffers.
This looks fine, although I'd much rather convert xtensa to the
generic DMA remap / uncached segment support.
Do you want this fix for 5.4? If so please queue it up ASAP so that
I can do the proper thing for 5.5. If you don't need it that urgent
I'd rather go straight to the generic code.
Hi Christoph,
On Wed, Oct 16, 2019 at 12:08 AM Christoph Hellwig <[email protected]> wrote:
> On Tue, Oct 15, 2019 at 02:25:26PM -0700, Max Filippov wrote:
> > Add trivial implementation for arch_dma_coherent_to_pfn.
> > This change enables communication with PCI ALSA devices through mmapped
> > buffers.
>
> This looks fine, although I'd much rather convert xtensa to the
> generic DMA remap / uncached segment support.
Thanks for the review.
> Do you want this fix for 5.4? If so please queue it up ASAP so that
> I can do the proper thing for 5.5. If you don't need it that urgent
> I'd rather go straight to the generic code.
There's no rush, I'll keep my version privately and will switch to the
generic version once it's available.
--
Thanks.
-- Max