linux-kernel - Re: [PATCH] efi/arm: fix allocation failure when reserving the kernel base

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Date:   Tue, 20 Aug 2019 15:28:25 +0300
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Russell King - ARM Linux admin <linux@...linux.org.uk>
Cc:     Chester Lin <clin@...e.com>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "rppt@...ux.ibm.com" <rppt@...ux.ibm.com>,
        "ren_guo@...ky.com" <ren_guo@...ky.com>,
        Juergen Gross <JGross@...e.com>,
        "geert@...ux-m68k.org" <geert@...ux-m68k.org>,
        "mingo@...nel.org" <mingo@...nel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        "guillaume.gardet@....com" <guillaume.gardet@....com>,
        Joey Lee <JLee@...e.com>, Gary Lin <GLin@...e.com>
Subject: Re: [PATCH] efi/arm: fix allocation failure when reserving the kernel base

On Tue, 20 Aug 2019 at 14:56, Russell King - ARM Linux admin
<linux@...linux.org.uk> wrote:
>
> On Fri, Aug 02, 2019 at 05:38:54AM +0000, Chester Lin wrote:
> > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> > index f3ce34113f89..909b11ba48d8 100644
> > --- a/arch/arm/mm/mmu.c
> > +++ b/arch/arm/mm/mmu.c
> > @@ -1184,6 +1184,9 @@ void __init adjust_lowmem_bounds(void)
> >               phys_addr_t block_start = reg->base;
> >               phys_addr_t block_end = reg->base + reg->size;
> >
> > +             if (memblock_is_nomap(reg))
> > +                     continue;
> > +
> >               if (reg->base < vmalloc_limit) {
> >                       if (block_end > lowmem_limit)
> >                               /*
>
> I think this hunk is sane - if the memory is marked nomap, then it isn't
> available for the kernel's use, so as far as calculating where the
> lowmem/highmem boundary is, it effectively doesn't exist and should be
> skipped.
>

I agree.

Chester, could you explain what you need beyond this change (and my
EFI stub change involving TEXT_OFFSET) to make things work on the
RPi2?