dmaengine: Fixup dmaengine_prep_slave_single() to be actually useful
dmaengine_prep_slave_single() is a helper function which is supposed to be used to prepare a transfer of a single contingous buffer. Currently the function takes a pointer to such a buffer from which it builds a scatterlist and passes it on to device_prep_slave_sg. The dmaengine framework requires that any scatterlist that is passed to device_prep_slave_sg is mapped and it may not be unmapped until the DMA operation has completed. This is not the here and any use of dmaengine_prep_slave_single() will lead to undefined behaviour (Most likely a system crash). This patch changes dmaengine_prep_slave_single() to take a dma_addr_t instead of a pointer to a buffer and moves the responsibility of mapping and unmapping the buffer up to the caller. Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
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@ -615,11 +615,13 @@ static inline int dmaengine_slave_config(struct dma_chan *chan,
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}
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static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
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struct dma_chan *chan, void *buf, size_t len,
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struct dma_chan *chan, dma_addr_t buf, size_t len,
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enum dma_transfer_direction dir, unsigned long flags)
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{
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struct scatterlist sg;
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sg_init_one(&sg, buf, len);
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sg_init_table(&sg, 1);
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sg_dma_address(&sg) = buf;
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sg_dma_len(&sg) = len;
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return chan->device->device_prep_slave_sg(chan, &sg, 1,
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dir, flags, NULL);
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