From 0aeba2d0d27c7341c10aeae7f013ad5f034d8b2d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 16 Dec 2018 18:19:45 +0100 Subject: [PATCH] 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 [mpe: s/dir/direction in dma_nommu_unmap_page()] Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/dma.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index dbfc7056d7df..9eb2cec15439 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -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