Hi, I'm trying to get my PrPMC800's running as NON-MONARCHS, but I have problems with DMA memory. Since the system is a NON-MONARCH, it has to be satisfied with whatever PCI-window is given to it by the PCI-monarch (which is not a Linux system).
The simple solution to this is to tweak the 'zones_size' array passed to 'free_area_init' to only make as much memory DMA-able as is given by the PCI-monarch, unfortunately this only works if the PCI-window is bigger than '1<<(PAGE_SHIFT+MAX_ORDER-1)' (due to alignment requirements in 'page_alloc. c'), and even then the DMA-able area will be less than optimal, since the DMA adresses starts at low addresses, and thus are filled with kernel pages, which does not need to be DMA-able. Is there anybody working on DISCONTIGOUS memory allocation for PowerPC's, that could shed some light on what should be done? A lot of memory management seems to be specialized for CONFIG_440, which further clutters my vision... Regards Anders Blomdell ------------------------------------------------------------------------------ Anders Blomdell Department of Automatic Control Email: anders.blomdell at control.lth. se Lund Institute of Technology Phone: +46 46 222 4625 Box 118, S-221 00 Lund, Sweden Fax: +46 46 138118 ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
