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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>
141 lines
2.8 KiB
C
141 lines
2.8 KiB
C
/*
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* linux/arch/alpha/kernel/pci-noop.c
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*
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* Stub PCI interfaces for Jensen-specific kernels.
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*/
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#include <linux/pci.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/gfp.h>
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#include <linux/capability.h>
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#include <linux/mm.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/dma-mapping.h>
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#include <linux/scatterlist.h>
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#include "proto.h"
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/*
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* The PCI controller list.
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*/
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struct pci_controller *hose_head, **hose_tail = &hose_head;
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struct pci_controller *pci_isa_hose;
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struct pci_controller * __init
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alloc_pci_controller(void)
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{
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struct pci_controller *hose;
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hose = alloc_bootmem(sizeof(*hose));
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*hose_tail = hose;
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hose_tail = &hose->next;
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return hose;
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}
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struct resource * __init
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alloc_resource(void)
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{
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struct resource *res;
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res = alloc_bootmem(sizeof(*res));
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return res;
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}
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asmlinkage long
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sys_pciconfig_iobase(long which, unsigned long bus, unsigned long dfn)
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{
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struct pci_controller *hose;
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/* from hose or from bus.devfn */
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if (which & IOBASE_FROM_HOSE) {
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for (hose = hose_head; hose; hose = hose->next)
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if (hose->index == bus)
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break;
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if (!hose)
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return -ENODEV;
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} else {
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/* Special hook for ISA access. */
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if (bus == 0 && dfn == 0)
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hose = pci_isa_hose;
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else
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return -ENODEV;
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}
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switch (which & ~IOBASE_FROM_HOSE) {
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case IOBASE_HOSE:
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return hose->index;
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case IOBASE_SPARSE_MEM:
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return hose->sparse_mem_base;
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case IOBASE_DENSE_MEM:
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return hose->dense_mem_base;
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case IOBASE_SPARSE_IO:
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return hose->sparse_io_base;
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case IOBASE_DENSE_IO:
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return hose->dense_io_base;
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case IOBASE_ROOT_BUS:
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return hose->bus->number;
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}
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return -EOPNOTSUPP;
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}
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asmlinkage long
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sys_pciconfig_read(unsigned long bus, unsigned long dfn,
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unsigned long off, unsigned long len, void *buf)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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else
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return -ENODEV;
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}
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asmlinkage long
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sys_pciconfig_write(unsigned long bus, unsigned long dfn,
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unsigned long off, unsigned long len, void *buf)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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else
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return -ENODEV;
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}
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static void *alpha_noop_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp,
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unsigned long attrs)
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{
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void *ret;
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if (!dev || *dev->dma_mask >= 0xffffffffUL)
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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) {
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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 int alpha_noop_supported(struct device *dev, u64 mask)
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{
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return mask < 0x00ffffffUL ? 0 : 1;
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}
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struct dma_map_ops alpha_noop_ops = {
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.alloc = alpha_noop_alloc_coherent,
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.free = dma_noop_free_coherent,
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.map_page = dma_noop_map_page,
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.map_sg = dma_noop_map_sg,
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.mapping_error = dma_noop_mapping_error,
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.dma_supported = alpha_noop_supported,
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};
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struct dma_map_ops *dma_ops = &alpha_noop_ops;
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EXPORT_SYMBOL(dma_ops);
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