mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 22:53:55 +08:00
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>
77 lines
1.6 KiB
C
77 lines
1.6 KiB
C
/*
|
|
* lib/dma-noop.c
|
|
*
|
|
* Simple DMA noop-ops that map 1:1 with memory
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/scatterlist.h>
|
|
|
|
static void *dma_noop_alloc(struct device *dev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t gfp,
|
|
unsigned long attrs)
|
|
{
|
|
void *ret;
|
|
|
|
ret = (void *)__get_free_pages(gfp, get_order(size));
|
|
if (ret)
|
|
*dma_handle = virt_to_phys(ret);
|
|
return ret;
|
|
}
|
|
|
|
static void dma_noop_free(struct device *dev, size_t size,
|
|
void *cpu_addr, dma_addr_t dma_addr,
|
|
unsigned long attrs)
|
|
{
|
|
free_pages((unsigned long)cpu_addr, get_order(size));
|
|
}
|
|
|
|
static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size,
|
|
enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
return page_to_phys(page) + offset;
|
|
}
|
|
|
|
static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
|
|
enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
int i;
|
|
struct scatterlist *sg;
|
|
|
|
for_each_sg(sgl, sg, nents, i) {
|
|
void *va;
|
|
|
|
BUG_ON(!sg_page(sg));
|
|
va = sg_virt(sg);
|
|
sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va);
|
|
sg_dma_len(sg) = sg->length;
|
|
}
|
|
|
|
return nents;
|
|
}
|
|
|
|
static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int dma_noop_supported(struct device *dev, u64 mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
struct dma_map_ops dma_noop_ops = {
|
|
.alloc = dma_noop_alloc,
|
|
.free = dma_noop_free,
|
|
.map_page = dma_noop_map_page,
|
|
.map_sg = dma_noop_map_sg,
|
|
.mapping_error = dma_noop_mapping_error,
|
|
.dma_supported = dma_noop_supported,
|
|
};
|
|
|
|
EXPORT_SYMBOL(dma_noop_ops);
|