Re: [PATCH] Revert "arm64: vmemmap: use virtual projection of linear region"

[David Daney]

On 03/08/2016 11:26 AM, Laura Abbott wrote:
> On 03/08/2016 11:03 AM, David Daney wrote:
> > From: David Daney <david.daney@xxxxxxxxxx>
> >
> > This reverts commit dfd55ad85e4a7fbaa82df12467515ac3c81e8a3e.
> >
> > Commit dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear
> > region") causes this failure on Cavium Thunder systems:
[...]
> See http://article.gmane.org/gmane.linux.ports.arm.kernel/484866 for a
> proposed fix.

Yes, that patch fixes it for me.  I withdraw my patch to revert.

Thanks,
David Daney

> > Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> > ---
> >   arch/arm64/include/asm/pgtable.h | 7 +++----
> >   arch/arm64/mm/init.c             | 4 ++--
> >   2 files changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/pgtable.h
> > b/arch/arm64/include/asm/pgtable.h
> > index f506086..bf464de 100644
> > --- a/arch/arm64/include/asm/pgtable.h
> > +++ b/arch/arm64/include/asm/pgtable.h
> > @@ -34,13 +34,13 @@
> >   /*
> >    * VMALLOC and SPARSEMEM_VMEMMAP ranges.
> >    *
> > - * VMEMAP_SIZE: allows the whole linear region to be covered by a
> > struct page array
> > + * VMEMAP_SIZE: allows the whole VA space to be covered by a struct
> > page array
> >    *    (rounded up to PUD_SIZE).
> >    * VMALLOC_START: beginning of the kernel VA space
> >    * VMALLOC_END: extends to the available space below vmmemmap, PCI
> > I/O space,
> >    *    fixed mappings and modules
> >    */
> > -#define VMEMMAP_SIZE        ALIGN((1UL << (VA_BITS - PAGE_SHIFT - 1))
> > * sizeof(struct page), PUD_SIZE)
> > +#define VMEMMAP_SIZE        ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) *
> > sizeof(struct page), PUD_SIZE)
> >
> >   #ifndef CONFIG_KASAN
> >   #define VMALLOC_START        (VA_START)
> > @@ -51,8 +51,7 @@
> >
> >   #define VMALLOC_END        (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE -
> > SZ_64K)
> >
> > -#define VMEMMAP_START        (VMALLOC_END + SZ_64K)
> > -#define vmemmap            ((struct page *)VMEMMAP_START -
> > (memstart_addr >> PAGE_SHIFT))
> > +#define vmemmap            ((struct page *)(VMALLOC_END + SZ_64K))
> >
> >   #define FIRST_USER_ADDRESS    0UL
> >
> > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> > index 7802f21..f3b061e 100644
> > --- a/arch/arm64/mm/init.c
> > +++ b/arch/arm64/mm/init.c
> > @@ -319,8 +319,8 @@ void __init mem_init(void)
> >   #endif
> >             MLG(VMALLOC_START, VMALLOC_END),
> >   #ifdef CONFIG_SPARSEMEM_VMEMMAP
> > -          MLG(VMEMMAP_START,
> > -              VMEMMAP_START + VMEMMAP_SIZE),
> > +          MLG((unsigned long)vmemmap,
> > +              (unsigned long)vmemmap + VMEMMAP_SIZE),
> >             MLM((unsigned long)virt_to_page(PAGE_OFFSET),
> >                 (unsigned long)virt_to_page(high_memory)),
> >   #endif