Re: Reading a physical memory location

[Clemens Koller <clemens.koller@anagramm.de>]

Manu Abraham schrieb:
> On 7/11/07, Nobin Mathew <nobin.mathew@gmail.com> wrote:
>> See this in the documentation
>>
>> The returned virtual address is a current CPU mapping for the memory
>> address given. It is only valid to use this function on addresses that
>> have a kernel mapping
>>
>> This function does not handle bus mappings for DMA transfers. In
>> almost all conceivable cases a device driver should not be using this
>> function
>>
> 
> To get a better idea, look here
> http://tldp.org/LDP/khg/HyperNews/get/devices/addrxlate.html

Very nice! I have two more questions:

1. Is the document up to date?

2. Can anybody give an example how to "map" lots of pages (which
got filled by i.e. a scatter gather DMA chain) from a driver
(kernel space) to userspace?

Thanks
-- 
Clemens Koller
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