On Mon, May 28, 2018 at 5:05 AM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > On Fri, May 25, 2018 at 10:09:52AM -0700, Andrey Smirnov wrote: >> On Fri, May 25, 2018 at 2:01 AM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: >> > On Thu, May 24, 2018 at 08:14:40PM -0700, Andrey Smirnov wrote: >> >> On Wed, May 23, 2018 at 1:43 AM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: >> >> > On Tue, May 22, 2018 at 10:10:12PM -0700, Andrey Smirnov wrote: >> >> >> The call to create_flat_mapping() in mmu.c will change both memory >> >> >> type and shareability of all RAM in use by barebox while MMU is on >> >> >> when done in conjunction with CONFIG_MMU_EARLY. >> >> > >> >> > I notice that with MMU_EARLY enabled we call create_flat_mapping() >> >> > twice, once in the early MMU code and once when setting up the MMU for >> >> > real. In between we remap the the SDRAM cached which then is reverted >> >> > during the second call to create_flat_mapping(). >> >> > >> >> > This seems unnecessary. Does the following help you? >> >> >> >> Yeah, this, disabling MMU before or having a tlb_invalidate() after >> >> all seem to help. Your patch works fine, but it has a slight weirdness >> >> in my case because early MMU code would mark OCRAM as cached and >> >> regular MMU code wouldn't undo it without the call to >> >> create_flat_mapping(), so I'd end up with slightly different memory >> >> configuration depending on if EARLY_MMU is enabled or not. Other than >> >> that it should work fine. >> >> >> >> The main reason I chose to go "disable MMU" route is because that >> >> follows what ARMv8 MMU code does, but I am perfectly happy with either >> >> solution. >> > >> > Disabling the MMU probably has a performance impact (I would have to >> > remeasure, maybe this is not true at all), that's why I would prefer >> > keeping it enabled. >> > >> >> OK, sure. Where do we go from here? Do you want to just take your >> patch or should I update mine, with its War And Peace of a commit >> message, and incorporate what you proposed? > > I applied my patch for now. We can still disable the MMU between PBL and > barebox later should we have to. > Sounds good, thanks! _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
