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[ARM] Update dma_map_sg()/dma_unmap_sg() API
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Update the ARM DMA scatter gather APIs for the scatterlist changes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Russell King authored and Russell King committed Sep 25, 2008
1 parent 0ddbccd commit afd1a32
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Showing 3 changed files with 115 additions and 125 deletions.
33 changes: 18 additions & 15 deletions arch/arm/common/dmabounce.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -435,21 +435,21 @@ int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
__func__, sg, nents, dir);

BUG_ON(dir == DMA_NONE);

for (i = 0; i < nents; i++, sg++) {
struct page *page = sg_page(sg);
unsigned int offset = sg->offset;
unsigned int length = sg->length;
for_each_sg(sg, s, nents, i) {
struct page *page = sg_page(s);
unsigned int offset = s->offset;
unsigned int length = s->length;
void *ptr = page_address(page) + offset;

sg->dma_address =
map_single(dev, ptr, length, dir);
s->dma_address = map_single(dev, ptr, length, dir);
}

return nents;
Expand All @@ -459,16 +459,17 @@ void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
__func__, sg, nents, dir);

BUG_ON(dir == DMA_NONE);

for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
for_each_sg(sg, s, nents, i) {
dma_addr_t dma_addr = s->dma_address;
unsigned int length = s->length;

unmap_single(dev, dma_addr, length, dir);
}
Expand Down Expand Up @@ -502,16 +503,17 @@ void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
__func__, sg, nents, dir);

BUG_ON(dir == DMA_NONE);

for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
for_each_sg(sg, s, nents, i) {
dma_addr_t dma_addr = s->dma_address;
unsigned int length = s->length;

sync_single(dev, dma_addr, length, dir);
}
Expand All @@ -521,16 +523,17 @@ void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
__func__, sg, nents, dir);

BUG_ON(dir == DMA_NONE);

for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
for_each_sg(sg, s, nents, i) {
dma_addr_t dma_addr = s->dma_address;
unsigned int length = s->length;

sync_single(dev, dma_addr, length, dir);
}
Expand Down
115 changes: 5 additions & 110 deletions arch/arm/include/asm/dma-mapping.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -281,75 +281,6 @@ dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
dma_unmap_single(dev, handle, size, dir);
}

/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scatter-gather version of the
* above dma_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 dma_map_single are
* the same here.
*/
#ifndef CONFIG_DMABOUNCE
static inline int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;

for (i = 0; i < nents; i++, sg++) {
char *virt;

sg->dma_address = page_to_dma(dev, sg_page(sg)) + sg->offset;
virt = sg_virt(sg);

if (!arch_is_coherent())
dma_cache_maint(virt, sg->length, dir);
}

return nents;
}
#else
extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif

/**
* dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Unmap a set of streaming mode DMA translations.
* Again, CPU read rules concerning calls here are the same as for
* dma_unmap_single() above.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{

/* nothing to do */
}
#else
extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif


/**
* dma_sync_single_range_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
Expand Down Expand Up @@ -405,50 +336,14 @@ dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
dma_sync_single_range_for_device(dev, handle, 0, size, dir);
}


/**
* dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Make physical memory consistent for a set of streaming
* mode DMA translations after a transfer.
*
* The same as dma_sync_single_for_* but for a scatter-gather list,
* same rules and usage.
/*
* The scatter list versions of the above methods.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;

for (i = 0; i < nents; i++, sg++) {
char *virt = sg_virt(sg);
if (!arch_is_coherent())
dma_cache_maint(virt, sg->length, dir);
}
}

static inline void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;

for (i = 0; i < nents; i++, sg++) {
char *virt = sg_virt(sg);
if (!arch_is_coherent())
dma_cache_maint(virt, sg->length, dir);
}
}
#else
extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
#endif


#ifdef CONFIG_DMABOUNCE
/*
Expand Down
92 changes: 92 additions & 0 deletions arch/arm/mm/dma-mapping.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -512,3 +512,95 @@ void dma_cache_maint(const void *start, size_t size, int direction)
}
}
EXPORT_SYMBOL(dma_cache_maint);

#ifndef CONFIG_DMABOUNCE
/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming mode for DMA.
* This is the scatter-gather version of the dma_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}.
*
* Device ownership issues as mentioned for dma_map_single are the same
* here.
*/
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

for_each_sg(sg, s, nents, i) {
s->dma_address = page_to_dma(dev, sg_page(s)) + s->offset;

if (!arch_is_coherent())
dma_cache_maint(sg_virt(s), s->length, dir);
}

return nents;
}
EXPORT_SYMBOL(dma_map_sg);

/**
* dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to unmap (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*
* Unmap a set of streaming mode DMA translations. Again, CPU access
* rules concerning calls here are the same as for dma_unmap_single().
*/
void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
/* nothing to do */
}
EXPORT_SYMBOL(dma_unmap_sg);

/**
* dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

for_each_sg(sg, s, nents, i) {
if (!arch_is_coherent())
dma_cache_maint(sg_virt(s), s->length, dir);
}
}
EXPORT_SYMBOL(dma_sync_sg_for_cpu);

/**
* dma_sync_sg_for_device
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;

for_each_sg(sg, s, nents, i) {
if (!arch_is_coherent())
dma_cache_maint(sg_virt(s), s->length, dir);
}
}
EXPORT_SYMBOL(dma_sync_sg_for_device);
#endif

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