ALSA: hda: Use new non-cached allocation for non-snoop mode

Now the ALSA memory allocator helper supports the new non-cached
pages, let's use the new type, SNDRV_DMA_TYPE_DEV_UC_SG, for HD-audio
driver.  This allows us to reduce lots of codes.

As another positive side-effect by this patch, the long-standing issue
with non-snoop mode playing in the non-mmap mode is fixed.  The core
memalloc helper does the proper pgprot setup for non-cached pages for
vmap(), which was missing in the past.

Reported-and-tested-by: Hans Hu <HansHu@zhaoxin.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_intel.c

@@ -397,61 +397,6 @@ static char *driver_short_names[] = {
 	[AZX_DRIVER_GENERIC] = "HD-Audio Generic",
 };
 
-#ifdef CONFIG_X86
-static void __mark_pages_wc(struct azx *chip, struct snd_dma_buffer *dmab, bool on)
-{
-	int pages;
-
-	if (azx_snoop(chip))
-		return;
-	if (!dmab || !dmab->area || !dmab->bytes)
-		return;
-
-#ifdef CONFIG_SND_DMA_SGBUF
-	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG) {
-		struct snd_sg_buf *sgbuf = dmab->private_data;
-		if (!chip->uc_buffer)
-			return; /* deal with only CORB/RIRB buffers */
-		if (on)
-			set_pages_array_wc(sgbuf->page_table, sgbuf->pages);
-		else
-			set_pages_array_wb(sgbuf->page_table, sgbuf->pages);
-		return;
-	}
-#endif
-
-	pages = (dmab->bytes + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	if (on)
-		set_memory_wc((unsigned long)dmab->area, pages);
-	else
-		set_memory_wb((unsigned long)dmab->area, pages);
-}
-
-static inline void mark_pages_wc(struct azx *chip, struct snd_dma_buffer *buf,
-				 bool on)
-{
-	__mark_pages_wc(chip, buf, on);
-}
-static inline void mark_runtime_wc(struct azx *chip, struct azx_dev *azx_dev,
-				   struct snd_pcm_substream *substream, bool on)
-{
-	if (azx_dev->wc_marked != on) {
-		__mark_pages_wc(chip, snd_pcm_get_dma_buf(substream), on);
-		azx_dev->wc_marked = on;
-	}
-}
-#else
-/* NOP for other archs */
-static inline void mark_pages_wc(struct azx *chip, struct snd_dma_buffer *buf,
-				 bool on)
-{
-}
-static inline void mark_runtime_wc(struct azx *chip, struct azx_dev *azx_dev,
-				   struct snd_pcm_substream *substream, bool on)
-{
-}
-#endif
-
 static int azx_acquire_irq(struct azx *chip, int do_disconnect);
 
 /*
@@ -2054,22 +1999,14 @@ static int dma_alloc_pages(struct hdac_bus *bus,
 			   struct snd_dma_buffer *buf)
 {
 	struct azx *chip = bus_to_azx(bus);
-	int err;
 
-	err = snd_dma_alloc_pages(type,
-				  bus->dev,
-				  size, buf);
-	if (err < 0)
-		return err;
-	mark_pages_wc(chip, buf, true);
-	return 0;
+	if (!azx_snoop(chip) && type == SNDRV_DMA_TYPE_DEV)
+		type = SNDRV_DMA_TYPE_DEV_UC;
+	return snd_dma_alloc_pages(type, bus->dev, size, buf);
 }
 
 static void dma_free_pages(struct hdac_bus *bus, struct snd_dma_buffer *buf)
 {
-	struct azx *chip = bus_to_azx(bus);
-
-	mark_pages_wc(chip, buf, false);
 	snd_dma_free_pages(buf);
 }
 
@@ -2077,22 +2014,12 @@ static int substream_alloc_pages(struct azx *chip,
 				 struct snd_pcm_substream *substream,
 				 size_t size)
 {
-	struct azx_dev *azx_dev = get_azx_dev(substream);
-	int ret;
-
-	mark_runtime_wc(chip, azx_dev, substream, false);
-	ret = snd_pcm_lib_malloc_pages(substream, size);
-	if (ret < 0)
-		return ret;
-	mark_runtime_wc(chip, azx_dev, substream, true);
-	return 0;
+	return snd_pcm_lib_malloc_pages(substream, size);
 }
 
 static int substream_free_pages(struct azx *chip,
 				struct snd_pcm_substream *substream)
 {
-	struct azx_dev *azx_dev = get_azx_dev(substream);
-	mark_runtime_wc(chip, azx_dev, substream, false);
 	return snd_pcm_lib_free_pages(substream);
 }