Messages in this thread | | | Date | Sat, 20 Mar 2004 12:50:53 -0800 | From | William Lee Irwin III <> | Subject | Re: can device drivers return non-ram via vm_ops->nopage? |
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On Sat, Mar 20, 2004 at 12:13:45PM -0800, Andrew Morton wrote: > I agree that ->nopage implementations should not be doing what that driver > is doing. ->nopage is defined to return a page*: it's crazy to be > returning someting from there which isn't covered by mem_map[]. > I just don't think it's important enough to be able to cope with > non-mem_map[] "memory" in do_no_page(), so I agree that requiring ->mmap() > to synchronously instantiate the pte's and retaining the debug check in > do_no_page() is a good idea.
There are other reasons for doing it, e.g. unusual TLB attributes and/or unusual pagetable structures backing the virtual region. I don't see anyone standing up and screaming for more functionality than cache coherency and/or disablement now, so as far as I'm concerned, remap_area_pages() (or rmk's stuff) kills the issue.
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