Albert Herranz wrote: > Benjamin Herrenschmidt wrote: >> On Sat, 2009-11-28 at 21:43 +0100, Albert Herranz wrote: >>> + * Prepare again the same BAT for MMU_init. >>> + * This allows udbg I/O to continue working after the MMU is >>> + * turned on for real. >>> + * >>> + * We are assuming here that exi_io_base is identity mapped. >>> + */ >>> + addr = ((unsigned long)exi_io_base) & 0xffff0000; >>> + setbat(1, addr, addr, 128*1024, PAGE_KERNEL_NCG); >> How do you prevent that from overlapping otherwise valid kernel >> mappings ? >> > > ug_udbg_init() is called from ppc_md.init_early.
^^^ This got here, but although it's true it doesn't apply here :) > It doesn't overlap any valid kernel mappings because exi_io_base is hardcoded > to an i/o region not used yet by the kernel. > See udbg_early_grab_exi_io_base(). > The setbat just prepares again, exactly in the same way, the same BAT that we > got setup by setup_usbgecko_bat in head_32.S. > Thanks, Albert _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
