Messages in this thread | | | From | (david parsons) | Subject | Re: holes for ISA boards... | Date | 14 Jun 1999 11:55:03 -0700 |
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In article <linux.kernel.19990613041154.32471.qmail@hog.ctrl-c.liu.se>, Christer Weinigel <wingel@hog.ctrl-c.liu.se> wrote: >Mark Jefferys <mjeffery@europa.com> wrote: > >>It was renamed to ioremap and moved to arch/<arch>/mm/ioremap.c . >> >>But this part of the patch looks bad to me anyway; it stops anyone from >>mapping part of the hole to VM, but presumably anything that does this >>knows what it's doing (probably a driver mapping memory straight from an >>ISA card). Or am I missing something? > >The test is the other way around from what you expect. Normally >vremap will return NULL for adresses below the top of memory (since it >probably would be a mistake to allow physical RAM to be mapped by a >driver), my patch excludes the memory hole from that test. > > if (MAP_NR(offset) < MAP_NR(high_memory) > && (offset < memory_hole_start || offset+size > memory_hole_end)) > return NULL;
So in the general case you'd want to have a flag in the mmap that says that memory foo can be used for a driver?
____ david parsons \bi/ Who's also got a patch for fancy e820 handling, but \/ who doesn't have any hardware that might actually take advantage of memory hole handling. I suppose I should really port it to 2.2, so people can test it with modern kernels.
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