Messages in this thread | | | Date | Tue, 03 May 2011 10:21:52 +0800 | From | 康剑斌 <> | Subject | Re: Can I/OAT DMA engineer access PCI MMIO space |
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>> 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.
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