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>

3 files changed, 8 insertions, 10 deletions

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 3a27b93e62619..44461626830e4 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -9,7 +9,6 @@
 #include <linux/kmemcheck.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-debug.h>
-#include <linux/dma-attrs.h>
 #include <asm/io.h>
 #include <asm/swiotlb.h>
 #include <linux/dma-contiguous.h>
@@ -48,11 +47,11 @@ extern int dma_supported(struct device *hwdev, u64 mask);
 
 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 					dma_addr_t *dma_addr, gfp_t flag,
-					struct dma_attrs *attrs);
+					unsigned long attrs);
 
 extern void dma_generic_free_coherent(struct device *dev, size_t size,
 				      void *vaddr, dma_addr_t dma_addr,
-				      struct dma_attrs *attrs);
+				      unsigned long attrs);
 
 #ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
 extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index ab05d73e2bb7b..d2f69b9ff7327 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -31,9 +31,9 @@ static inline void dma_mark_clean(void *addr, size_t size) {}
 
 extern void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 					dma_addr_t *dma_handle, gfp_t flags,
-					struct dma_attrs *attrs);
+					unsigned long attrs);
 extern void x86_swiotlb_free_coherent(struct device *dev, size_t size,
 					void *vaddr, dma_addr_t dma_addr,
-					struct dma_attrs *attrs);
+					unsigned long attrs);
 
 #endif /* _ASM_X86_SWIOTLB_H */
diff --git a/arch/x86/include/asm/xen/page-coherent.h b/arch/x86/include/asm/xen/page-coherent.h
index acd844c017d3f..f02f025ff988b 100644
--- a/arch/x86/include/asm/xen/page-coherent.h
+++ b/arch/x86/include/asm/xen/page-coherent.h
@@ -2,12 +2,11 @@
 #define _ASM_X86_XEN_PAGE_COHERENT_H
 
 #include <asm/page.h>
-#include <linux/dma-attrs.h>
 #include <linux/dma-mapping.h>
 
 static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
 		dma_addr_t *dma_handle, gfp_t flags,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	void *vstart = (void*)__get_free_pages(flags, get_order(size));
 	*dma_handle = virt_to_phys(vstart);
@@ -16,18 +15,18 @@ static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
 
 static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 		void *cpu_addr, dma_addr_t dma_handle,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	free_pages((unsigned long) cpu_addr, get_order(size));
 }
 
 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
 	     dma_addr_t dev_addr, unsigned long offset, size_t size,
-	     enum dma_data_direction dir, struct dma_attrs *attrs) { }
+	     enum dma_data_direction dir, unsigned long attrs) { }
 
 static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir,
-		struct dma_attrs *attrs) { }
+		unsigned long attrs) { }
 
 static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
 		dma_addr_t handle, size_t size, enum dma_data_direction dir) { }