MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.

This only matters for ISA devices with a 24-bit DMA limit or for devices
with a 32-bit DMA limit on systems with ZONE_DMA32 enabled.  The latter
currently only affects 32-bit PCI cards on Sibyte-based systems with more
than 1GB RAM installed.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 20 insertions, 8 deletions

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 7ba890860d9..469d4019f79 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -44,27 +44,39 @@ static inline int cpu_is_noncoherent_r10000(struct device *dev)
 
 static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
 {
+        gfp_t dma_flag;
+
         /* ignore region specifiers */
         gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
 
-#ifdef CONFIG_ZONE_DMA
+#ifdef CONFIG_ISA
         if (dev == NULL)
-                gfp |= __GFP_DMA;
-        else if (dev->coherent_dma_mask < DMA_BIT_MASK(24))
-                gfp |= __GFP_DMA;
+                dma_flag = __GFP_DMA;
         else
 #endif
-#ifdef CONFIG_ZONE_DMA32
+#if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
              if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
-                gfp |= __GFP_DMA32;
+                        dma_flag = __GFP_DMA;
+        else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+                        dma_flag = __GFP_DMA32;
+        else
+#endif
+#if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
+             if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+                dma_flag = __GFP_DMA32;
+        else
+#endif
+#if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
+             if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+                dma_flag = __GFP_DMA;
         else
 #endif
-                ;
+                dma_flag = 0;
 
         /* Don't invoke OOM killer */
         gfp |= __GFP_NORETRY;
 
-        return gfp;
+        return gfp | dma_flag;
 }
 
 void *dma_alloc_noncoherent(struct device *dev, size_t size,