ALSA: pcm - fix page conversion on non-coherent PPC arch

The non-cohernet PPC arch doesn't give the correct address by a simple
virt_to_page() for pages allocated via dma_alloc_coherent().
This patch adds a hack to fix the conversion similarly like MIPS.

Note that this doesn't fix perfectly: the pages should be marked with
proper pgprot value.  This will be done in a future implementation like
the conversion to dma_mmap_coherent().

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index e48c5f618578..29ab46a12e11 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3070,6 +3070,16 @@ snd_pcm_default_page_ops(struct snd_pcm_substream *substream, unsigned long ofs)
         if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)
                 return virt_to_page(CAC_ADDR(vaddr));
 #endif
+#if defined(CONFIG_PPC32) && defined(CONFIG_NOT_COHERENT_CACHE)
+        if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) {
+                dma_addr_t addr = substream->runtime->dma_addr + ofs;
+                addr -= get_dma_offset(substream->dma_buffer.dev.dev);
+                /* assume dma_handle set via pfn_to_phys() in
+                 * mm/dma-noncoherent.c
+                 */
+                return pfn_to_page(addr >> PAGE_SHIFT);
+        }
+#endif
         return virt_to_page(vaddr);
 }