Messages in this thread | | | Date | Wed, 27 Aug 2014 20:56:50 +0530 | Subject | Re: [PATCH 1/2] ARM: LPAE: load upper bits of early TTBR0/TTBR1 | From | Jassi Brar <> |
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On Tue, Jul 29, 2014 at 5:59 PM, Konstantin Khlebnikov <koct9i@gmail.com> wrote: > On Mon, Jul 28, 2014 at 10:47 PM, Will Deacon <will.deacon@arm.com> wrote: >> On Mon, Jul 28, 2014 at 07:40:58PM +0100, Konstantin Khlebnikov wrote: >>> On Mon, Jul 28, 2014 at 10:12 PM, Will Deacon <will.deacon@arm.com> wrote: >>> > On Tue, Jul 22, 2014 at 04:36:23PM +0100, Konstantin Khlebnikov wrote: >>> >> This patch fixes booting when idmap pgd lays above 4gb. Commit >>> >> 4756dcbfd37 mostly had fixed this, but it'd failed to load upper bits. >>> >> >>> >> Also this fixes adding TTBR1_OFFSET to TTRR1: if lower part overflows >>> >> carry flag must be added to the upper part. >>> >> >>> >> Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> >>> >> Cc: Cyril Chemparathy <cyril@ti.com> >>> >> Cc: Vitaly Andrianov <vitalya@ti.com> >>> >> --- >>> >> arch/arm/mm/proc-v7-3level.S | 7 +++---- >>> >> 1 file changed, 3 insertions(+), 4 deletions(-) >>> >> >>> >> diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S >>> >> index 22e3ad6..f0481dd 100644 >>> >> --- a/arch/arm/mm/proc-v7-3level.S >>> >> +++ b/arch/arm/mm/proc-v7-3level.S >>> >> @@ -140,12 +140,11 @@ ENDPROC(cpu_v7_set_pte_ext) >>> >> mov \tmp, \ttbr1, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits >>> >> mov \ttbr1, \ttbr1, lsl #ARCH_PGD_SHIFT @ lower bits >>> >> addls \ttbr1, \ttbr1, #TTBR1_OFFSET >>> >> - mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 >>> >> + adcls \tmp, \tmp, #0 >>> >> + mcrr p15, 1, \ttbr1, \tmp, c2 @ load TTBR1 >>> >> mov \tmp, \ttbr0, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits >>> >> mov \ttbr0, \ttbr0, lsl #ARCH_PGD_SHIFT @ lower bits >>> >> - mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0 >>> >> - mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 >>> >> - mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0 >>> >> + mcrr p15, 0, \ttbr0, \tmp, c2 @ load TTBR0 >>> > >>> > I must admit, the code you are removing here looks really strange. Was there >>> > a badly resolved conflict somewhere along the way? It would be nice to see >>> > if your fix (which seems ok to me) was actually present in the mailing list >>> > posting of the patch that ended in the above mess. >>> >>> Nope, no merge conflicts, source in original patch >>> https://lkml.org/lkml/2012/9/11/346 >>> >>> That mess completely harmless, this code is used only once on boot. >>> I don't have that email, so replying isn't trivial for me. >> >> How bizarre. Also, Cyril doesn't work for TI anymore (his email is >> bouncing), so it's tricky to know what he meant here. >> >> Your patch looks better than what we currently have though. Have you managed >> to test it on a keystone platform (I don't have one)? > > No, I don't have it too. As well as I don't have direct access to the > platform where > problem was found. I've debugged this in patched qemu. > It seems the patch wasn't tested on any real platform, I did on my CA15 based platform - it breaks boot. Simply reverting the patch gets it going again. I am happy to try any fix.
Thanks Jassi
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