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, 10 insertions, 10 deletions

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index cb557d28cb21..b2eadd6fa9a1 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -131,7 +131,7 @@ static void *mips_dma_alloc_noncoherent(struct device *dev, size_t size,
 }
 
 static void *mips_dma_alloc_coherent(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;
 	struct page *page = NULL;
@@ -141,7 +141,7 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 	 * XXX: seems like the coherent and non-coherent implementations could
 	 * be consolidated.
 	 */
-	if (dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs))
+	if (attrs & DMA_ATTR_NON_CONSISTENT)
 		return mips_dma_alloc_noncoherent(dev, size, dma_handle, gfp);
 
 	gfp = massage_gfp_flags(dev, gfp);
@@ -176,13 +176,13 @@ static void mips_dma_free_noncoherent(struct device *dev, size_t size,
 }
 
 static void mips_dma_free_coherent(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)
 {
 	unsigned long addr = (unsigned long) vaddr;
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	struct page *page = NULL;
 
-	if (dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs)) {
+	if (attrs & DMA_ATTR_NON_CONSISTENT) {
 		mips_dma_free_noncoherent(dev, size, vaddr, dma_handle);
 		return;
 	}
@@ -200,7 +200,7 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 
 static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 	void *cpu_addr, dma_addr_t dma_addr, size_t size,
-	struct dma_attrs *attrs)
+	unsigned long attrs)
 {
 	unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -214,7 +214,7 @@ static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 
 	pfn = page_to_pfn(virt_to_page((void *)addr));
 
-	if (dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
+	if (attrs & DMA_ATTR_WRITE_COMBINE)
 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 	else
 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
@@ -291,7 +291,7 @@ static inline void __dma_sync(struct page *page,
 }
 
 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
-	size_t size, enum dma_data_direction direction, struct dma_attrs *attrs)
+	size_t size, enum dma_data_direction direction, unsigned long attrs)
 {
 	if (cpu_needs_post_dma_flush(dev))
 		__dma_sync(dma_addr_to_page(dev, dma_addr),
@@ -301,7 +301,7 @@ static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 }
 
 static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
-	int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
+	int nents, enum dma_data_direction direction, unsigned long attrs)
 {
 	int i;
 	struct scatterlist *sg;
@@ -322,7 +322,7 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 	unsigned long offset, size_t size, enum dma_data_direction direction,
-	struct dma_attrs *attrs)
+	unsigned long attrs)
 {
 	if (!plat_device_is_coherent(dev))
 		__dma_sync(page, offset, size, direction);
@@ -332,7 +332,7 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 
 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 	int nhwentries, enum dma_data_direction direction,
-	struct dma_attrs *attrs)
+	unsigned long attrs)
 {
 	int i;
 	struct scatterlist *sg;