DMA from high memory regions

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Hi,

I am trying to setup DMA to/from user space. I get a user pointer in my
device driver, from which I build up kiobuf and call map_user_kiobuf. After
this, I call kmap to map pages to kernel virtual space and then virt_to_bus
to get bus address. Now if I define CONFIG_HIGHMEM and that page happens to
be in the memory region near 1GB then DMA never happens and I donot see any
data in result pointer. If CONFIG_HIGHMEM is not defined, then everything
works perfectly. Please suggest any solution.

Thanks,
Imran.

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• Next message: Matthew Dobson: "[patch] boot hang on multi-quad machines."
• Previous message: Doug Ledford: "Re: [PATCH] 2.5.24 : drivers/scsi/dpt_i2o.c (DMA Rev. 2)"
• In reply to: Simon Kirby: "Re: Linux 2.4.19-rc1"
• Next in thread: Imran Badr: "RE: DMA from high memory regions"
• Maybe reply: Imran Badr: "RE: DMA from high memory regions"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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