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

[Anshuman Khandual]

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.

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);