[PATCH v2 2/2] dma-direct: Try reallocation with GFP_DMA32 if possible

[Takashi Iwai]

This patch adds a similar fallback reallocation with GFP_DMA32 as
we've done with GFP_DMA.  The condition is that the coherent mask is
smaller than 64bit (i.e. some address limitation), and neither GFP_DMA
nor GFP_DMA32 is set beforehand.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
 lib/dma-direct.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index bbfb229aa067..970d39155618 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -84,6 +84,13 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		__free_pages(page, page_order);
 		page = NULL;
 
+		if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
+		    dev->coherent_dma_mask < DMA_BIT_MASK(64) &&
+		    !(gfp & (GFP_DMA32 | GFP_DMA))) {
+			gfp |= GFP_DMA32;
+			goto again;
+		}
+
 		if (IS_ENABLED(CONFIG_ZONE_DMA) &&
 		    dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
 		    !(gfp & GFP_DMA)) {
-- 
2.16.3


--Multipart_Thu_Apr_12_10:27:50_2018-1--