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>
114 lines
2.8 KiB
C
114 lines
2.8 KiB
C
/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/dma-mapping.h>
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#include <linux/list.h>
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#include <linux/pci.h>
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#include <linux/export.h>
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#include <linux/highmem.h>
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#include <linux/scatterlist.h>
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#include <asm/io.h>
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static void *frv_dma_alloc(struct device *hwdev, 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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ret = consistent_alloc(gfp, size, dma_handle);
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if (ret)
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memset(ret, 0, size);
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return ret;
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}
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static void frv_dma_free(struct device *hwdev, 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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consistent_free(vaddr);
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}
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static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
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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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unsigned long dampr2;
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void *vaddr;
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int i;
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struct scatterlist *sg;
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BUG_ON(direction == DMA_NONE);
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dampr2 = __get_DAMPR(2);
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for_each_sg(sglist, sg, nents, i) {
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vaddr = kmap_atomic_primary(sg_page(sg));
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frv_dcache_writeback((unsigned long) vaddr,
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(unsigned long) vaddr + PAGE_SIZE);
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}
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kunmap_atomic_primary(vaddr);
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if (dampr2) {
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__set_DAMPR(2, dampr2);
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__set_IAMPR(2, dampr2);
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}
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return nents;
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}
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static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
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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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flush_dcache_page(page);
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return (dma_addr_t) page_to_phys(page) + offset;
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}
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static void frv_dma_sync_single_for_device(struct device *dev,
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dma_addr_t dma_handle, size_t size,
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enum dma_data_direction direction)
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{
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flush_write_buffers();
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}
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static void frv_dma_sync_sg_for_device(struct device *dev,
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struct scatterlist *sg, int nelems,
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enum dma_data_direction direction)
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{
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flush_write_buffers();
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}
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static int frv_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 frv_dma_ops = {
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.alloc = frv_dma_alloc,
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.free = frv_dma_free,
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.map_page = frv_dma_map_page,
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.map_sg = frv_dma_map_sg,
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.sync_single_for_device = frv_dma_sync_single_for_device,
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.sync_sg_for_device = frv_dma_sync_sg_for_device,
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.dma_supported = frv_dma_supported,
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};
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EXPORT_SYMBOL(frv_dma_ops);
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