[PATCH 1/2] arm64: mm: add missing P4D definitions and use them consistently

[Ard Biesheuvel]

On Mon, 8 Mar 2021 at 10:06, Anshuman Khandual
<anshuman.khandual at arm.com> wrote:
>
>
>
> On 3/4/21 10:41 PM, Ard Biesheuvel wrote:
> > Even though level 0, 1 and 2 descriptors share the same attribute
> > encodings, let's be a bit more consistent about using the right one at
> > the right level. So add new macros for level 0/P4D definitions, and
> > clean up some inconsistencies involving these macros.
> >
> > Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
> > ---
> >  arch/arm64/include/asm/pgtable-hwdef.h | 9 +++++++++
> >  arch/arm64/mm/mmu.c                    | 6 +++---
> >  2 files changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
> > index 42442a0ae2ab..e64e77a345b2 100644
> > --- a/arch/arm64/include/asm/pgtable-hwdef.h
> > +++ b/arch/arm64/include/asm/pgtable-hwdef.h
> > @@ -94,6 +94,15 @@
> >  /*
> >   * Hardware page table definitions.
> >   *
> > + * Level 0 descriptor (P4D).
> > + */
> > +#define P4D_TYPE_TABLE               (_AT(p4dval_t, 3) << 0)
> > +#define P4D_TABLE_BIT                (_AT(p4dval_t, 1) << 1)
> > +#define P4D_TYPE_MASK                (_AT(p4dval_t, 3) << 0)
> > +#define P4D_TYPE_SECT                (_AT(p4dval_t, 1) << 0)
> > +#define P4D_SECT_RDONLY              (_AT(p4dval_t, 1) << 7)         /* AP[2] */
> > +
> > +/*
> >   * Level 1 descriptor (PUD).
> >   */
> >  #define PUD_TYPE_TABLE               (_AT(pudval_t, 3) << 0)
> > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> > index 3802cfbdd20d..029091474042 100644
> > --- a/arch/arm64/mm/mmu.c
> > +++ b/arch/arm64/mm/mmu.c
> > @@ -309,7 +309,7 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
> >               phys_addr_t pud_phys;
> >               BUG_ON(!pgtable_alloc);
> >               pud_phys = pgtable_alloc(PUD_SHIFT);
> > -             __p4d_populate(p4dp, pud_phys, PUD_TYPE_TABLE);
> > +             __p4d_populate(p4dp, pud_phys, P4D_TYPE_TABLE);
> >               p4d = READ_ONCE(*p4dp);
> >       }
> >       BUG_ON(p4d_bad(p4d));
> > @@ -1209,11 +1209,11 @@ void __init early_fixmap_init(void)
> >               pudp = pud_offset_kimg(p4dp, addr);
> >       } else {
> >               if (p4d_none(p4d))
> > -                     __p4d_populate(p4dp, __pa_symbol(bm_pud), PUD_TYPE_TABLE);
> > +                     __p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE);
> >               pudp = fixmap_pud(addr);
> >       }
> >       if (pud_none(READ_ONCE(*pudp)))
> > -             __pud_populate(pudp, __pa_symbol(bm_pmd), PMD_TYPE_TABLE);
> > +             __pud_populate(pudp, __pa_symbol(bm_pmd), PUD_TYPE_TABLE);
> >       pmdp = fixmap_pmd(addr);
> >       __pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE);
> >
> >
>
> I guess there are still some more similar inconsistencies around.
>

Indeed - I will fix those as well in v2.

Thanks,
Ard.

> diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
> index 3c6a7f5988b1..27cc643d0509 100644
> --- a/arch/arm64/include/asm/pgalloc.h
> +++ b/arch/arm64/include/asm/pgalloc.h
> @@ -27,7 +27,7 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
>
>  static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
>  {
> -       __pud_populate(pudp, __pa(pmdp), PMD_TYPE_TABLE);
> +       __pud_populate(pudp, __pa(pmdp), PUD_TYPE_TABLE);
>  }
>  #else
>  static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
> @@ -45,7 +45,7 @@ static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
>
>  static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
>  {
> -       __p4d_populate(p4dp, __pa(pudp), PUD_TYPE_TABLE);
> +       __p4d_populate(p4dp, __pa(pudp), P4D_TYPE_TABLE);
>  }
>  #else
>  static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
> diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> index d8e66c78440e..9fe40cbbd8c0 100644
> --- a/arch/arm64/mm/kasan_init.c
> +++ b/arch/arm64/mm/kasan_init.c
> @@ -79,7 +79,7 @@ static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
>                 phys_addr_t pmd_phys = early ?
>                                 __pa_symbol(kasan_early_shadow_pmd)
>                                         : kasan_alloc_zeroed_page(node);
> -               __pud_populate(pudp, pmd_phys, PMD_TYPE_TABLE);
> +               __pud_populate(pudp, pmd_phys, PUD_TYPE_TABLE);
>         }
>
>         return early ? pmd_offset_kimg(pudp, addr) : pmd_offset(pudp, addr);
> @@ -92,7 +92,7 @@ static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node,
>                 phys_addr_t pud_phys = early ?
>                                 __pa_symbol(kasan_early_shadow_pud)
>                                         : kasan_alloc_zeroed_page(node);
> -               __p4d_populate(p4dp, pud_phys, PMD_TYPE_TABLE);
> +               __p4d_populate(p4dp, pud_phys, P4D_TYPE_TABLE);
>         }
>
>         return early ? pud_offset_kimg(p4dp, addr) : pud_offset(p4dp, addr);