MIPS: loongson: remove loongson_dma_supported

swiotlb_dma_supported will always return true for a mask large enough to
cover the DMA addresses for all physical memory, which is the right
thing to do for swiotlb based dma ops.  This function returned false
if the mask was bigger than a firmware set dma_mask_bits that apparently
can be either 32 or 64, and which seems completely buggys if it actually
is not 64, as the false return negates the whole point of swiotlb.

Signed-off-by: Christoph Hellwig <[email protected]>
Patchwork: https://patchwork.linux-mips.org/patch/19533/
Signed-off-by: Paul Burton <[email protected]>
Cc: Florian Fainelli <[email protected]>
Cc: David Daney <[email protected]>
Cc: Kevin Cernekee <[email protected]>
Cc: Jiaxun Yang <[email protected]>
Cc: Tom Bogendoerfer <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: [email protected]
Cc: [email protected]

diff --git a/arch/mips/loongson64/common/dma-swiotlb.c b/arch/mips/loongson64/common/dma-swiotlb.c
index 6a739f8ae1108b718d209f8b598feeba80b8c030..a5e50f2ec301601db900585d2ce60e4fc5da1976 100644 (file)
--- a/arch/mips/loongson64/common/dma-swiotlb.c
+++ b/arch/mips/loongson64/common/dma-swiotlb.c
@@ -56,13 +56,6 @@ static void loongson_dma_sync_sg_for_device(struct device *dev,
        mb();
 }
 
-static int loongson_dma_supported(struct device *dev, u64 mask)
-{
-       if (mask > DMA_BIT_MASK(loongson_sysconf.dma_mask_bits))
-               return 0;
-       return swiotlb_dma_supported(dev, mask);
-}
-
 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
        long nid;
@@ -99,7 +92,7 @@ static const struct dma_map_ops loongson_dma_map_ops = {
        .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
        .sync_sg_for_device = loongson_dma_sync_sg_for_device,
        .mapping_error = swiotlb_dma_mapping_error,
-       .dma_supported = loongson_dma_supported,
+       .dma_supported = swiotlb_dma_supported,
 };
 
 void __init plat_swiotlb_setup(void)