Re: Can I/OAT DMA engineer access PCI MMIO space

[Koul, Vinod]

On Tue, 2011-05-03 at 10:21 +0800, ååæ wrote:
> >> I try to use ioatdam to copy data from system memory to pci MMIO space:
> >> If dst points to a memory space, the operation would pass.
> >> But if dst points to a pci MMIO space, it failed with kernel oops.
> >> It seems the code:
> >> BUG_ON(is_ioat_bug(chanerr));
> >> in drivers/dma/ioat/dma_v3.c, line 365 cause the oops.
> >> Is there anyway to access pci MMIO space using ioat?
> >> The datasheet says that ioat supports MMIO access.
> > Did you map the IO memory in kernel using ioremap and friends first?
> >
> yes, I had used 'ioremap_nocache' to map the IO memory and I can use
> memcpy to copy data to this region. The async_tx should have been 
> correctly configured as
> I can use aync_memcpy to copy data between different system memory address.
Then you should be using memcpy_toio() and friends

~Vinod

-- 
~Vinod

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