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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>
120 lines
2.9 KiB
C
120 lines
2.9 KiB
C
/* Glue code to lib/swiotlb.c */
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#include <linux/pci.h>
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/swiotlb.h>
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#include <linux/bootmem.h>
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#include <linux/dma-mapping.h>
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#include <asm/iommu.h>
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#include <asm/swiotlb.h>
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#include <asm/dma.h>
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#include <asm/xen/swiotlb-xen.h>
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#include <asm/iommu_table.h>
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int swiotlb __read_mostly;
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void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t flags,
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unsigned long attrs)
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{
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void *vaddr;
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/*
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* Don't print a warning when the first allocation attempt fails.
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* swiotlb_alloc_coherent() will print a warning when the DMA
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* memory allocation ultimately failed.
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*/
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flags |= __GFP_NOWARN;
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vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
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attrs);
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if (vaddr)
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return vaddr;
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return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
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}
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void x86_swiotlb_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_addr,
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unsigned long attrs)
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{
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if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
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swiotlb_free_coherent(dev, size, vaddr, dma_addr);
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else
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dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
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}
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static struct dma_map_ops swiotlb_dma_ops = {
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.mapping_error = swiotlb_dma_mapping_error,
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.alloc = x86_swiotlb_alloc_coherent,
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.free = x86_swiotlb_free_coherent,
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.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
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.sync_single_for_device = swiotlb_sync_single_for_device,
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.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
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.sync_sg_for_device = swiotlb_sync_sg_for_device,
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.map_sg = swiotlb_map_sg_attrs,
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.unmap_sg = swiotlb_unmap_sg_attrs,
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.map_page = swiotlb_map_page,
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.unmap_page = swiotlb_unmap_page,
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.dma_supported = NULL,
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};
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/*
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* pci_swiotlb_detect_override - set swiotlb to 1 if necessary
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*
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* This returns non-zero if we are forced to use swiotlb (by the boot
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* option).
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*/
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int __init pci_swiotlb_detect_override(void)
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{
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int use_swiotlb = swiotlb | swiotlb_force;
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if (swiotlb_force)
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swiotlb = 1;
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return use_swiotlb;
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}
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IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
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pci_xen_swiotlb_detect,
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pci_swiotlb_init,
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pci_swiotlb_late_init);
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/*
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* if 4GB or more detected (and iommu=off not set) return 1
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* and set swiotlb to 1.
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*/
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int __init pci_swiotlb_detect_4gb(void)
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{
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/* don't initialize swiotlb if iommu=off (no_iommu=1) */
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#ifdef CONFIG_X86_64
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if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
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swiotlb = 1;
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#endif
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return swiotlb;
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}
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IOMMU_INIT(pci_swiotlb_detect_4gb,
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pci_swiotlb_detect_override,
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pci_swiotlb_init,
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pci_swiotlb_late_init);
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void __init pci_swiotlb_init(void)
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{
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if (swiotlb) {
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swiotlb_init(0);
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dma_ops = &swiotlb_dma_ops;
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}
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}
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void __init pci_swiotlb_late_init(void)
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{
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/* An IOMMU turned us off. */
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if (!swiotlb)
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swiotlb_free();
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else {
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printk(KERN_INFO "PCI-DMA: "
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"Using software bounce buffering for IO (SWIOTLB)\n");
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swiotlb_print_info();
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}
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}
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