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>
99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/* Fallback functions when the main IOMMU code is not compiled in. This
|
|
code is roughly equivalent to i386. */
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/string.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/iommu.h>
|
|
#include <asm/dma.h>
|
|
|
|
static int
|
|
check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
|
|
{
|
|
if (hwdev && !dma_capable(hwdev, bus, size)) {
|
|
if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
|
|
printk(KERN_ERR
|
|
"nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
|
|
name, (long long)bus, size,
|
|
(long long)*hwdev->dma_mask);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size,
|
|
enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
dma_addr_t bus = page_to_phys(page) + offset;
|
|
WARN_ON(size == 0);
|
|
if (!check_addr("map_single", dev, bus, size))
|
|
return DMA_ERROR_CODE;
|
|
flush_write_buffers();
|
|
return bus;
|
|
}
|
|
|
|
/* Map a set of buffers described by scatterlist in streaming
|
|
* mode for DMA. This is the scatter-gather version of the
|
|
* above pci_map_single interface. Here the scatter gather list
|
|
* elements are each tagged with the appropriate dma address
|
|
* and length. They are obtained via sg_dma_{address,length}(SG).
|
|
*
|
|
* NOTE: An implementation may be able to use a smaller number of
|
|
* DMA address/length pairs than there are SG table elements.
|
|
* (for example via virtual mapping capabilities)
|
|
* The routine returns the number of addr/length pairs actually
|
|
* used, at most nents.
|
|
*
|
|
* Device ownership issues as mentioned above for pci_map_single are
|
|
* the same here.
|
|
*/
|
|
static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
|
|
int nents, enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
struct scatterlist *s;
|
|
int i;
|
|
|
|
WARN_ON(nents == 0 || sg[0].length == 0);
|
|
|
|
for_each_sg(sg, s, nents, i) {
|
|
BUG_ON(!sg_page(s));
|
|
s->dma_address = sg_phys(s);
|
|
if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
|
|
return 0;
|
|
s->dma_length = s->length;
|
|
}
|
|
flush_write_buffers();
|
|
return nents;
|
|
}
|
|
|
|
static void nommu_sync_single_for_device(struct device *dev,
|
|
dma_addr_t addr, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
flush_write_buffers();
|
|
}
|
|
|
|
|
|
static void nommu_sync_sg_for_device(struct device *dev,
|
|
struct scatterlist *sg, int nelems,
|
|
enum dma_data_direction dir)
|
|
{
|
|
flush_write_buffers();
|
|
}
|
|
|
|
struct dma_map_ops nommu_dma_ops = {
|
|
.alloc = dma_generic_alloc_coherent,
|
|
.free = dma_generic_free_coherent,
|
|
.map_sg = nommu_map_sg,
|
|
.map_page = nommu_map_page,
|
|
.sync_single_for_device = nommu_sync_single_for_device,
|
|
.sync_sg_for_device = nommu_sync_sg_for_device,
|
|
.is_phys = 1,
|
|
};
|