On 10/12/2017 11:20 AM, David Laight wrote:
I'm pretty sure that kzalloc does not make that guarantee, and I don't think dma_alloc_coherent does either.
dma_alloc_coherent() definitely does. And I've a driver that relies on it (for 16k blocks).
What about when an IOMMU is used? The DMA address that gets returned is not necessarily the physical address of the memory buffer.
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