dma-mapping: use unsigned long for dma_attrs

The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Acked-by: Vineet Gupta <[email protected]>
Acked-by: Robin Murphy <[email protected]>
Acked-by: Hans-Christian Noren Egtvedt <[email protected]>
Acked-by: Mark Salter <[email protected]> [c6x]
Acked-by: Jesper Nilsson <[email protected]> [cris]
Acked-by: Daniel Vetter <[email protected]> [drm]
Reviewed-by: Bart Van Assche <[email protected]>
Acked-by: Joerg Roedel <[email protected]> [iommu]
Acked-by: Fabien Dessenne <[email protected]> [bdisp]
Reviewed-by: Marek Szyprowski <[email protected]> [vb2-core]
Acked-by: David Vrabel <[email protected]> [xen]
Acked-by: Konrad Rzeszutek Wilk <[email protected]> [xen swiotlb]
Acked-by: Joerg Roedel <[email protected]> [iommu]
Acked-by: Richard Kuo <[email protected]> [hexagon]
Acked-by: Geert Uytterhoeven <[email protected]> [m68k]
Acked-by: Gerald Schaefer <[email protected]> [s390]
Acked-by: Bjorn Andersson <[email protected]>
Acked-by: Hans-Christian Noren Egtvedt <[email protected]> [avr32]
Acked-by: Vineet Gupta <[email protected]> [arc]
Acked-by: Robin Murphy <[email protected]> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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

@@ -1,8 +1,6 @@
 #ifndef _ALPHA_DMA_MAPPING_H
 #define _ALPHA_DMA_MAPPING_H
 
-#include <linux/dma-attrs.h>
-
 extern struct dma_map_ops *dma_ops;
 
 static inline struct dma_map_ops *get_dma_ops(struct device *dev)

arch/alpha/kernel/pci-noop.c

@@ -109,7 +109,7 @@ sys_pciconfig_write(unsigned long bus, unsigned long dfn,
 
 static void *alpha_noop_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t gfp,
-				       struct dma_attrs *attrs)
+				       unsigned long attrs)
 {
 	void *ret;
 

arch/alpha/kernel/pci_iommu.c

@@ -349,7 +349,7 @@ static struct pci_dev *alpha_gendev_to_pci(struct device *dev)
 static dma_addr_t alpha_pci_map_page(struct device *dev, struct page *page,
 				     unsigned long offset, size_t size,
 				     enum dma_data_direction dir,
-				     struct dma_attrs *attrs)
+				     unsigned long attrs)
 {
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
 	int dac_allowed;
@@ -369,7 +369,7 @@ static dma_addr_t alpha_pci_map_page(struct device *dev, struct page *page,
 
 static void alpha_pci_unmap_page(struct device *dev, dma_addr_t dma_addr,
 				 size_t size, enum dma_data_direction dir,
-				 struct dma_attrs *attrs)
+				 unsigned long attrs)
 {
 	unsigned long flags;
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
@@ -433,7 +433,7 @@ static void alpha_pci_unmap_page(struct device *dev, dma_addr_t dma_addr,
 
 static void *alpha_pci_alloc_coherent(struct device *dev, size_t size,
 				      dma_addr_t *dma_addrp, gfp_t gfp,
-				      struct dma_attrs *attrs)
+				      unsigned long attrs)
 {
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
 	void *cpu_addr;
@@ -478,7 +478,7 @@ try_again:
 
 static void alpha_pci_free_coherent(struct device *dev, size_t size,
 				    void *cpu_addr, dma_addr_t dma_addr,
-				    struct dma_attrs *attrs)
+				    unsigned long attrs)
 {
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
 	pci_unmap_single(pdev, dma_addr, size, PCI_DMA_BIDIRECTIONAL);
@@ -651,7 +651,7 @@ sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,
 
 static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg,
 			    int nents, enum dma_data_direction dir,
-			    struct dma_attrs *attrs)
+			    unsigned long attrs)
 {
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
 	struct scatterlist *start, *end, *out;
@@ -729,7 +729,7 @@ static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg,
 
 static void alpha_pci_unmap_sg(struct device *dev, struct scatterlist *sg,
 			       int nents, enum dma_data_direction dir,
-			       struct dma_attrs *attrs)
+			       unsigned long attrs)
 {
 	struct pci_dev *pdev = alpha_gendev_to_pci(dev);
 	unsigned long flags;