dma-direct: unify the dma_capable definitions

Currently each architectures that wants to override dma_to_phys and
phys_to_dma also has to provide dma_capable.  But there isn't really
any good reason for that.  powerpc and mips just have copies of the
generic one minus the latests fix, and the arm one was the inspiration
for said fix, but misses the bus_dma_mask handling.
Make all architectures use the generic version instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

arch/arm/include/asm/dma-direct.h

@@ -14,23 +14,4 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	u64 limit, mask;
-
-	if (!dev->dma_mask)
-		return 0;
-
-	mask = *dev->dma_mask;
-
-	limit = (mask + 1) & ~mask;
-	if (limit && size > limit)
-		return 0;
-
-	if ((addr | (addr + size - 1)) & ~mask)
-		return 0;
-
-	return 1;
-}
-
 #endif /* ASM_ARM_DMA_DIRECT_H */

arch/mips/include/asm/dma-direct.h

@@ -2,14 +2,6 @@
 #ifndef _MIPS_DMA_DIRECT_H
 #define _MIPS_DMA_DIRECT_H 1
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr);
 phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr);
 

arch/powerpc/include/asm/dma-direct.h

@@ -2,15 +2,6 @@
 #ifndef ASM_POWERPC_DMA_DIRECT_H
 #define ASM_POWERPC_DMA_DIRECT_H 1
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <=
-		min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
-}
-
 static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
 	if (!dev)

include/linux/dma-direct.h

@@ -24,6 +24,7 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 
 	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
 }
+#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
 
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 {
@@ -38,7 +39,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 
 	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
 }
-#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
 
 #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
 bool force_dma_unencrypted(struct device *dev);