On Tue, 2007-10-09 at 02:28 +1000, Nick Piggin wrote: > On Tuesday 09 October 2007 18:55, Huang, Ying wrote: > > On Tue, 2007-10-09 at 02:06 +1000, Nick Piggin wrote: > > > > I'm just wondering whether you really need to access highmem in > > > boot code... > > > > Because the zero page (boot_parameters) of i386 boot protocol has 4k > > limitation, a linked list style boot parameter passing mechanism (struct > > setup_data) is proposed by Peter Anvin. The linked list is provided by > > bootloader, so it is possible to be in highmem region. > > OK. I don't really know the code, but I trust you ;)
Thank you :) > > > > Definitely on most architectures it would just amount to > > > memcpy(dst, __va(phys), n);, right? However I don't know if > > > > Yes. > > > > > it's worth the trouble of overriding it unless there is some > > > non-__init user of it. > > > > To support debugging and kexec, the boot parameters include the linked > > list above are exported into sysfs. This function is used there too. The > > patch is the No. 2 of the series. > > Ah, I see. I missed that. > > OK, well rather than make it weak, and have everyone except > i386 override it, can you just ifdef CONFIG_HIGHMEM? Yes. This is better. I will do it. Maybe it can be defined as a macro for these architectures, as follow: /* in linux/mm.h */ #ifdef CONFIG_HIGHMEM void *copy_from_phys(void *to, unsigned long from_phys, size_t n); #else #define copy_from_phys(dst, phys, n) memcpy(dst, __va(phys), n) #endif > After that, I guess most other architectures wouldn't even > use the function. Maybe it can go into lib/ instead so that > it can be discarded by the linker if it isn't used? Yes. I will do it. Best Regards, Huang Ying - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
