00085f1efa
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>
79 lines
2 KiB
C
79 lines
2 KiB
C
/*
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* Dynamic DMA mapping support.
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*
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* On cris there is no hardware dynamic DMA address translation,
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* so consistent alloc/free are merely page allocation/freeing.
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* The rest of the dynamic DMA mapping interface is implemented
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* in asm/pci.h.
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*
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* Borrowed from i386.
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*/
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/pci.h>
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#include <linux/gfp.h>
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#include <asm/io.h>
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static void *v32_dma_alloc(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
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{
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void *ret;
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/* ignore region specifiers */
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gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
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if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
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gfp |= GFP_DMA;
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ret = (void *)__get_free_pages(gfp, get_order(size));
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if (ret != NULL) {
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memset(ret, 0, size);
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*dma_handle = virt_to_phys(ret);
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}
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return ret;
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}
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static void v32_dma_free(struct device *dev, size_t size, void *vaddr,
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dma_addr_t dma_handle, unsigned long attrs)
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{
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free_pages((unsigned long)vaddr, get_order(size));
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}
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static inline dma_addr_t v32_dma_map_page(struct device *dev,
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struct page *page, unsigned long offset, size_t size,
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enum dma_data_direction direction, unsigned long attrs)
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{
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return page_to_phys(page) + offset;
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}
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static inline int v32_dma_map_sg(struct device *dev, struct scatterlist *sg,
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int nents, enum dma_data_direction direction,
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unsigned long attrs)
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{
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printk("Map sg\n");
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return nents;
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}
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static inline int v32_dma_supported(struct device *dev, u64 mask)
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{
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/*
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* we fall back to GFP_DMA when the mask isn't all 1s,
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* so we can't guarantee allocations that must be
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* within a tighter range than GFP_DMA..
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*/
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if (mask < 0x00ffffff)
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return 0;
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return 1;
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}
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struct dma_map_ops v32_dma_ops = {
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.alloc = v32_dma_alloc,
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.free = v32_dma_free,
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.map_page = v32_dma_map_page,
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.map_sg = v32_dma_map_sg,
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.dma_supported = v32_dma_supported,
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};
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EXPORT_SYMBOL(v32_dma_ops);
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