[PATCH v2 05/10] mips: use for_each_sg()

From: Akinobu Mita
Date: Fri May 01 2015 - 09:59:22 EST


This replaces the plain loop over the sglist array with for_each_sg()
macro which consists of sg_next() function calls. Since mips doesn't
select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in
order to loop over each sg element. But this can help find problems
with drivers that do not properly initialize their sg tables when
CONFIG_DEBUG_SG is enabled.

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
---
* Changes from v1
- Update commit log

arch/mips/mm/dma-default.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 609d124..eeaf024 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -262,12 +262,13 @@ static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
plat_unmap_dma_mem(dev, dma_addr, size, direction);
}

-static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg,
+static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
{
int i;
+ struct scatterlist *sg;

- for (i = 0; i < nents; i++, sg++) {
+ for_each_sg(sglist, sg, nents, i) {
if (!plat_device_is_coherent(dev))
__dma_sync(sg_page(sg), sg->offset, sg->length,
direction);
@@ -291,13 +292,14 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
return plat_map_dma_mem_page(dev, page) + offset;
}

-static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nhwentries, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
int i;
+ struct scatterlist *sg;

- for (i = 0; i < nhwentries; i++, sg++) {
+ for_each_sg(sglist, sg, nhwentries, i) {
if (!plat_device_is_coherent(dev) &&
direction != DMA_TO_DEVICE)
__dma_sync(sg_page(sg), sg->offset, sg->length,
@@ -324,26 +326,34 @@ static void mips_dma_sync_single_for_device(struct device *dev,
}

static void mips_dma_sync_sg_for_cpu(struct device *dev,
- struct scatterlist *sg, int nelems, enum dma_data_direction direction)
+ struct scatterlist *sglist, int nelems,
+ enum dma_data_direction direction)
{
int i;
+ struct scatterlist *sg;

- if (cpu_needs_post_dma_flush(dev))
- for (i = 0; i < nelems; i++, sg++)
+ if (cpu_needs_post_dma_flush(dev)) {
+ for_each_sg(sglist, sg, nelems, i) {
__dma_sync(sg_page(sg), sg->offset, sg->length,
direction);
+ }
+ }
plat_post_dma_flush(dev);
}

static void mips_dma_sync_sg_for_device(struct device *dev,
- struct scatterlist *sg, int nelems, enum dma_data_direction direction)
+ struct scatterlist *sglist, int nelems,
+ enum dma_data_direction direction)
{
int i;
+ struct scatterlist *sg;

- if (!plat_device_is_coherent(dev))
- for (i = 0; i < nelems; i++, sg++)
+ if (!plat_device_is_coherent(dev)) {
+ for_each_sg(sglist, sg, nelems, i) {
__dma_sync(sg_page(sg), sg->offset, sg->length,
direction);
+ }
+ }
}

int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/