Messages in this thread | | | Date | Mon, 16 Dec 2013 15:46:01 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH 1/3] arm64: add EFI stub |
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On Fri, Dec 06, 2013 at 02:55:54PM +0000, Mark Salter wrote: > On Thu, 2013-12-05 at 14:18 +0000, Catalin Marinas wrote: > > On Fri, Nov 29, 2013 at 10:05:10PM +0000, Mark Salter wrote: > > > + add x2, sp, 16 > > > + str x8, [x2] > > > + bl efi_entry > > > + cmn x0, #1 > > > + b.eq efi_load_fail > > > + > > > + /* > > > + * efi_entry() will have relocated the kernel image if necessary > > > + * and we return here with device tree address in x0 and the kernel > > > + * entry point stored at *image_addr. Save those values in registers > > > + * which are preserved by __flush_dcache_all. > > > + */ > > > + ldr x1, [sp, #16] > > > + mov x20, x0 > > > + mov x21, x1 > > > + > > > + bl __flush_dcache_all > > > > Regarding __flush_dcache_all, I plan to remove it for all cases apart > > from power management with the MMU disabled. With MMU enabled, there is > > no guarantee that this function does the right thing. It's even worse in > > the guest context. > > According to booting.txt, the dcache needs to be invalidated. Is there > something existing I can use or do I need to write it?
The function will stay for a few cases where needed. But here the D-cache and MMU are still on at this point and there is a slight chance of speculative loads after the flush (though only clean lines). You could move this after he MMU disabling (but still keep the I-cache on for performance).
-- Catalin
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