Messages in this thread | | | Subject | Re: remap_page_range in 2.2.7 | From | (Tony E. Bennett) | Date | 09 Jun 1999 13:09:48 -0400 |
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I also had this problem. Ended up using the nopage entry point to map the pages. Works fine on 2.0 and 2.2 kernels.
eg: mmap: calls get_free_page() repeatedly (my dma engine does not need contiguous physmem: hurray!) saving the addresses return 0
nopage: looks up the appropriate page in my saved info returns phys addr of that page
I think I got this technique from Rubini's book
fmcgirt@swcp.com writes:
> I have posted this earlier but no response. I am using remap_page_range to > map a kernel dma buffer to user space by setting RESERVED bit in appropriate > pages. I am unable to find the problem - has remap_page_range changed from > 2.0.x to 2.2.x so that it does not work on RAM even with the RESERVED bit > set???? Others doing the same have also posted the same problem (without > resolution) so I don't think it is just me. All other uses of remap work > fine - such as with PCI mmeory regions. About ready to go to something else > and give up for the time being but hope there is a solution. > > Earlier Posting: > > I have a contiguous memory buffer in my driver that I have allocated by: > > bufAddress = __get_dma_pages(GFP_KERNEL,order); > > that I want to map to user space.
--tony
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