Hi, Matt Thanks a lot for replying, your help is very much appreciated. I've followed your suggestion and now ioremap works as expected. I've removed ivocation of m4xx_map_io() replacing it by normal ioremaps for serial ports, RTC and ethernet adapter.
It would be great to see this stuff cleaned up in 2.6. Felix. Matt Porter wrote: >On Tue, Nov 09, 2004 at 07:27:09PM +0200, Felix Radensky wrote: > > >>Hi, folks >> >>I have a 405GPr based board with 512M of RAM. >>My kernel is 2.4.17 from Monta Vista Linux 2.1. >>I'm trying to reserve 64M on boot using mem=448M >>and map it later by >> >>ioremap(__pa(high_memory), 64*(1<<20)); >> >>This worked fine when system had 256M of RAM, >>but now ioremap fails. If I understand the kernel >>code correctly, by adding more RAM I've reduced >>the vmalloc/ioremap space. I can also see that this >>space is reduced dramatically on boot by mappings >>done in arch/ppc/kernel/ppc4xx_setup.c:m4xx_map_io() >> >>Is there any way to fix problem ? Is it necessary to have >>a 1:1 virtual to physical mappings as its done in m4xx_map_io() >>or maybe higher virtual addresses can be used, thus >>allowing to save some precious ioremap space. >> >> > >This is exactly why the PPC44x ports don't use io_block_map()... >it can interfere with dynamic mappings. It is not necessary to >have 1:1 virtual to physical mappings nor is it necessary to >have m4xx_map_io() at all. One can use ioremap() to map any >space and let the kernel place things intelligently. In order >to use serial console you'll have to use early_serial_setup() >after you've ioremapped the UART...once you've removed the >io_block_map() call. Look at other ports to see how this is >done. > >Someday I might get down my list to cleaning up 40x stuff in 2.6. > >-Matt > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ozlabs.org/pipermail/linuxppc-embedded/attachments/20041110/f33dae2a/attachment.htm
