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, 0 insertions, 71 deletions

diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h
deleted file mode 100644
index 5246239a4953..000000000000
--- a/include/linux/dma-attrs.h
+++ /dev/null
@@ -1,71 +0,0 @@
-#ifndef _DMA_ATTR_H
-#define _DMA_ATTR_H
-
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
-#include <linux/bug.h>
-
-/**
- * an enum dma_attr represents an attribute associated with a DMA
- * mapping. The semantics of each attribute should be defined in
- * Documentation/DMA-attributes.txt.
- */
-enum dma_attr {
-	DMA_ATTR_WRITE_BARRIER,
-	DMA_ATTR_WEAK_ORDERING,
-	DMA_ATTR_WRITE_COMBINE,
-	DMA_ATTR_NON_CONSISTENT,
-	DMA_ATTR_NO_KERNEL_MAPPING,
-	DMA_ATTR_SKIP_CPU_SYNC,
-	DMA_ATTR_FORCE_CONTIGUOUS,
-	DMA_ATTR_ALLOC_SINGLE_PAGES,
-	DMA_ATTR_MAX,
-};
-
-#define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX)
-
-/**
- * struct dma_attrs - an opaque container for DMA attributes
- * @flags - bitmask representing a collection of enum dma_attr
- */
-struct dma_attrs {
-	unsigned long flags[__DMA_ATTRS_LONGS];
-};
-
-#define DEFINE_DMA_ATTRS(x) 					\
-	struct dma_attrs x = {					\
-		.flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 },	\
-	}
-
-static inline void init_dma_attrs(struct dma_attrs *attrs)
-{
-	bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS);
-}
-
-/**
- * dma_set_attr - set a specific attribute
- * @attr: attribute to set
- * @attrs: struct dma_attrs (may be NULL)
- */
-static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
-{
-	if (attrs == NULL)
-		return;
-	BUG_ON(attr >= DMA_ATTR_MAX);
-	__set_bit(attr, attrs->flags);
-}
-
-/**
- * dma_get_attr - check for a specific attribute
- * @attr: attribute to set
- * @attrs: struct dma_attrs (may be NULL)
- */
-static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
-{
-	if (attrs == NULL)
-		return 0;
-	BUG_ON(attr >= DMA_ATTR_MAX);
-	return test_bit(attr, attrs->flags);
-}
-
-#endif /* _DMA_ATTR_H */