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powerpc/dma: properly wire up the unmap_page and unmap_sg methods 

The unmap methods need to transfer memory ownership back from the
device to the cpu by identical means as dma_sync_*_to_cpu. I'm not
sure powerpc needs to do any work in this transfer direction, but
given that it does invalidate the caches in dma_sync_*_to_cpu already
we should make sure we also do so on unmapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[mpe: s/dir/direction in dma_nommu_unmap_page()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hifive-unleashed-5.1
Christoph Hellwig 2018-12-16 18:19:45 +01:00 committed by Michael Ellerman
parent 9286356907
commit 0aeba2d0d2
1 changed files with 8 additions and 1 deletions
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9
arch/powerpc/kernel/dma.c
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@ -210,10 +210,15 @@ static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
return nents;
}
static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sg,
static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i)
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
static u64 dma_nommu_get_required_mask(struct device *dev)
@ -247,6 +252,8 @@ static inline void dma_nommu_unmap_page(struct device *dev,
enum dma_data_direction direction,
unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync(bus_to_virt(dma_address), size, direction);
}
#ifdef CONFIG_NOT_COHERENT_CACHE