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/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index cbc78b4117b5..8cf97cbadc91 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -19,7 +19,7 @@
 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
 
 static void *m68k_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
-		gfp_t flag, struct dma_attrs *attrs)
+		gfp_t flag, unsigned long attrs)
 {
 	struct page *page, **map;
 	pgprot_t pgprot;
@@ -62,7 +62,7 @@ static void *m68k_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 }
 
 static void m68k_dma_free(struct device *dev, size_t size, void *addr,
-		dma_addr_t handle, struct dma_attrs *attrs)
+		dma_addr_t handle, unsigned long attrs)
 {
 	pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
 	vfree(addr);
@@ -73,7 +73,7 @@ static void m68k_dma_free(struct device *dev, size_t size, void *addr,
 #include <asm/cacheflush.h>
 
 static void *m68k_dma_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	void *ret;
 	/* ignore region specifiers */
@@ -91,7 +91,7 @@ static void *m68k_dma_alloc(struct device *dev, size_t size,
 }
 
 static void m68k_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, struct dma_attrs *attrs)
+		dma_addr_t dma_handle, unsigned long attrs)
 {
 	free_pages((unsigned long)vaddr, get_order(size));
 }
@@ -130,7 +130,7 @@ static void m68k_dma_sync_sg_for_device(struct device *dev,
 
 static dma_addr_t m68k_dma_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)
 {
 	dma_addr_t handle = page_to_phys(page) + offset;
 
@@ -139,7 +139,7 @@ static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
 }
 
 static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
-		int nents, enum dma_data_direction dir, struct dma_attrs *attrs)
+		int nents, enum dma_data_direction dir, unsigned long attrs)
 {
 	int i;
 	struct scatterlist *sg;