On Tue, Jun 18, 2013 at 5:34 AM, Arnd Bergmann <a...@arndb.de> wrote: > On Monday 17 June 2013, Chao Xie wrote: >> On Fri, Jun 14, 2013 at 8:56 PM, Arnd Bergmann <a...@arndb.de> wrote: >> > On Friday 14 June 2013 17:15:33 Chao Xie wrote: >> >> On Mon, Jun 10, 2013 at 4:35 PM, Arnd Bergmann <a...@arndb.de> wrote: >> > >> >> > I guess that is a problem we have on other platforms as well, we should >> >> > find a generic solution for that. It would be nice to reserve a page >> >> > in "fixmap" and have common code map the SCU page into that. >> >> > >> >> >> >> So you mean that reserve a page in arch/arm/asm/include/fixmap.h? >> > >> > Yes. >> > >> >> This reserve will depend on the cpu type beacuse only A9 will have SCU >> >> part. >> > >> > I think A5 and ARM11MPCore as well. >> > >> >> I do not know that in fixmap, the #ifdef is acceptable or not. >> > >> > Yes, it is. We don't really use fixmap on ARM for anything other than >> > kmap_atomic at the moment. Please have a look at the powerpc and x86 >> > implementations. >> > >> >> For the common code to map the SCU page, where do you suggest to put it? >> > >> > arch/arm/kernel/smp_scu.c. >> > >> I think smp_scu.c may not be good place to put the mapping for SCU page. >> As you know that the fix map will make use of the mapping that set up >> by vector page. >> It will make use of top_pmd, and some APIs only provided under arch/arm/mm/. >> For example >> get_mem_type: for the pgprot for MT_DEVICE >> set_top_pte: >> Is that possible to add a file fixmap.c under arch/arm/mm/? It can >> including all the fix mapping >> except highmem. So SCU is one of it. > > It's up to Russell, and he probably has an idea where this should be > going. > > Russell, do you think using a fixmap page for the SCU makes sense? > I'm looking for a method to consolidate the various methods of > doing early mappings of the SCU for device tree based platforms. > Where do you think that should be implemented? > Hi, Russell
What do you think about above suggestion? Thanks. > Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
