dma-mapping: move the dma_coherent flag to struct device

Various architectures support both coherent and non-coherent dma on a
per-device basis.  Move the dma_noncoherent flag from the mips archdata
field to struct device proper to prepare the infrastructure for reuse on
other architectures.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/mips/include/asm/Kbuild

@@ -1,6 +1,7 @@
 # MIPS headers
 generic-(CONFIG_GENERIC_CSUM) += checksum.h
 generic-y += current.h
+generic-y += device.h
 generic-y += dma-contiguous.h
 generic-y += emergency-restart.h
 generic-y += export.h

arch/mips/include/asm/device.h

@@ -1,19 +0,0 @@
-/*
- * Arch specific extensions to struct device
- *
- * This file is released under the GPLv2
- */
-#ifndef _ASM_MIPS_DEVICE_H
-#define _ASM_MIPS_DEVICE_H
-
-struct dev_archdata {
-#ifdef CONFIG_DMA_PERDEV_COHERENT
-	/* Non-zero if DMA is coherent with CPU caches */
-	bool dma_coherent;
-#endif
-};
-
-struct pdev_archdata {
-};
-
-#endif /* _ASM_MIPS_DEVICE_H*/

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

@@ -20,6 +20,12 @@ enum coherent_io_user_state {
 #elif defined(CONFIG_DMA_MAYBE_COHERENT)
 extern enum coherent_io_user_state coherentio;
 extern int hw_coherentio;
+
+static inline bool dev_is_dma_coherent(struct device *dev)
+{
+	return coherentio == IO_COHERENCE_ENABLED ||
+		(coherentio == IO_COHERENCE_DEFAULT && hw_coherentio);
+}
 #else
 #ifdef CONFIG_DMA_NONCOHERENT
 #define coherentio	IO_COHERENCE_DISABLED

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

@@ -25,7 +25,7 @@ static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
 				      bool coherent)
 {
 #ifdef CONFIG_DMA_PERDEV_COHERENT
-	dev->archdata.dma_coherent = coherent;
+	dev->dma_coherent = coherent;
 #endif
 }