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>
86 lines
2.7 KiB
C
86 lines
2.7 KiB
C
/*
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* Copyright (C) 2014-2015 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __DMA_IOMMU_H
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#define __DMA_IOMMU_H
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#ifdef __KERNEL__
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#include <asm/errno.h>
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#ifdef CONFIG_IOMMU_DMA
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#include <linux/iommu.h>
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int iommu_dma_init(void);
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/* Domain management interface for IOMMU drivers */
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int iommu_get_dma_cookie(struct iommu_domain *domain);
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void iommu_put_dma_cookie(struct iommu_domain *domain);
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/* Setup call for arch DMA mapping code */
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int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
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/* General helpers for DMA-API <-> IOMMU-API interaction */
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int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
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/*
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* These implement the bulk of the relevant DMA mapping callbacks, but require
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* the arch code to take care of attributes and cache maintenance
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*/
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struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
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unsigned long attrs, int prot, dma_addr_t *handle,
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void (*flush_page)(struct device *, const void *, phys_addr_t));
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void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
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dma_addr_t *handle);
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int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
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dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size, int prot);
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int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
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int nents, int prot);
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/*
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* Arch code with no special attribute handling may use these
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* directly as DMA mapping callbacks for simplicity
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*/
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void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
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enum dma_data_direction dir, unsigned long attrs);
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void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
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enum dma_data_direction dir, unsigned long attrs);
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int iommu_dma_supported(struct device *dev, u64 mask);
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int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
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#else
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struct iommu_domain;
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static inline int iommu_dma_init(void)
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{
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return 0;
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}
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static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
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{
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return -ENODEV;
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}
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static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
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{
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}
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#endif /* CONFIG_IOMMU_DMA */
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#endif /* __KERNEL__ */
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#endif /* __DMA_IOMMU_H */
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