powerpc: Implement dma_mmap_coherent()

This is used by Alsa to mmap buffers allocated with dma_alloc_coherent()
into userspace. We need a special variant to handle machines with
non-coherent DMAs as those buffers have "special" virt addresses and
require non-cachable mappings

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 6d2416a85709..dd70fac57ec8 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -42,6 +42,7 @@ extern void __dma_free_coherent(size_t size, void *vaddr);
 extern void __dma_sync(void *vaddr, size_t size, int direction);
 extern void __dma_sync_page(struct page *page, unsigned long offset,
                                  size_t size, int direction);
+extern unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr);
 
 #else /* ! CONFIG_NOT_COHERENT_CACHE */
 /*
@@ -198,6 +199,11 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 
+extern int dma_mmap_coherent(struct device *, struct vm_area_struct *,
+                             void *, dma_addr_t, size_t);
+#define ARCH_HAS_DMA_MMAP_COHERENT
+
+
 static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
                 enum dma_data_direction direction)
 {