On Mon, 23 Feb 2026 at 23:23, Mark Kettenis <[email protected]> wrote:
>
> > Hi Mark,
>
> Hi Ilias,
>
> Sorry for the late reply.  I was a bit busy the last weeks...
>
> > On Sat, 10 Jan 2026 at 21:56, Mark Kettenis <[email protected]> wrote:
> > >
> > > Commit 9ebdbbc43e5f ("arm: armv8: invalidate dcache entries on
> > > dcache_enable") broke Apple Silicon machines in certain scenarios.
> > > If the MMU is currently not enabled we need to flush the TLB
> > > before we enable it to prevent stale TLB entries from becoming
> > > active again.  So move the __asm_invalidate_tlb_all() back
> > > immediately before the mmu_setup() call.
> > >
> > > Fixes: 9ebdbbc43e5f ("arm: armv8: invalidate dcache entries on 
> > > dcache_enable")
> > > Signed-off-by: Mark Kettenis <[email protected]>
> > > ---
> >
> > Should we keep the check here or mayber move it in mmu_setup()?
>
> It would make sense to move it to mmu_setup(), but I went for a
> partial revert as there is an alternative implementation of
> mmu_setup() in cpu/armv8/fsl-layerscape/cpu.c and I couldn't test that
> code.
>
> Hope this can still make the next release.

Ok that's unfortunate. Let's get it in now since it's a fix

Reviewed-by: Ilias Apalodimas <[email protected]>

>
> > Thanks
> > /Ilias
> >
> > >  arch/arm/cpu/armv8/cache_v8.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > > diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
> > > index 0309da6d397..39479df7b21 100644
> > > --- a/arch/arm/cpu/armv8/cache_v8.c
> > > +++ b/arch/arm/cpu/armv8/cache_v8.c
> > > @@ -878,15 +878,16 @@ void flush_dcache_range(unsigned long start, 
> > > unsigned long stop)
> > >  void dcache_enable(void)
> > >  {
> > >         /* The data cache is not active unless the mmu is enabled */
> > > -       if (!mmu_status())
> > > +       if (!mmu_status()) {
> > > +               __asm_invalidate_tlb_all();
> > >                 mmu_setup();
> > > +       }
> > >
> > >         /* Set up page tables only once (it is done also by mmu_setup()) 
> > > */
> > >         if (!gd->arch.tlb_fillptr)
> > >                 setup_all_pgtables();
> > >
> > >         invalidate_dcache_all();
> > > -       __asm_invalidate_tlb_all();
> > >         set_sctlr(get_sctlr() | CR_C);
> > >  }

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