From 00085f1efa387a8ce100e3734920f7639c80caa3 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Wed, 3 Aug 2016 13:46:00 -0700 Subject: 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 Acked-by: Vineet Gupta Acked-by: Robin Murphy Acked-by: Hans-Christian Noren Egtvedt Acked-by: Mark Salter [c6x] Acked-by: Jesper Nilsson [cris] Acked-by: Daniel Vetter [drm] Reviewed-by: Bart Van Assche Acked-by: Joerg Roedel [iommu] Acked-by: Fabien Dessenne [bdisp] Reviewed-by: Marek Szyprowski [vb2-core] Acked-by: David Vrabel [xen] Acked-by: Konrad Rzeszutek Wilk [xen swiotlb] Acked-by: Joerg Roedel [iommu] Acked-by: Richard Kuo [hexagon] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Gerald Schaefer [s390] Acked-by: Bjorn Andersson Acked-by: Hans-Christian Noren Egtvedt [avr32] Acked-by: Vineet Gupta [arc] Acked-by: Robin Murphy [arm64 and dma-iommu] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/dma-attrs.h | 71 ----------------------------------------------- 1 file changed, 71 deletions(-) delete mode 100644 include/linux/dma-attrs.h (limited to 'include/linux/dma-attrs.h') 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 -#include -#include - -/** - * 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 */ -- cgit v1.2.3-55-g7522