Re: [PATCH] OMAP: iommu flush page table entries from L1 and L2cache

From: Russell King - ARM Linux
Date: Fri Apr 15 2011 - 04:13:26 EST

On Fri, Apr 15, 2011 at 11:24:16AM +0900, KyongHo Cho wrote:
> That means we need to translate logical to physical address and it is
> sometimes not trivial.

What do you mean "sometimes not trivial" ? The DMA does nothing more
than virt_to_phys(virt) to get the physical address. It's _that_ simple.

If virt_to_phys(virt) is likely to fail, there's protection in the DMA API
to BUG_ON() in that case.

> Finally, the kernel will contain many similar routines that do same thing.

So when we get coherent DMA, you won't care that the DMA API functions
start doing nothing with caches?
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