On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote:
> powerpc used to set the pte specific flags in set_pte_at(). This is different
> from other architectures. To be consistent with other architecture update
> pfn_pte to set _PAGE_PTE on ppc64. Also, drop now unused pte_mkpte.
>
> We add a VM_WARN_ON() to catch the usage of calling set_pte_at() without
> setting
> _PAGE_PTE bit. We will remove that after a few releases.
>
> With respect to huge pmd entries, pmd_mkhuge() takes care of adding the
> _PAGE_PTE bit.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
> ---
> arch/powerpc/include/asm/book3s/64/pgtable.h | 15 +++++++++------
> arch/powerpc/include/asm/nohash/pgtable.h | 5 -----
> arch/powerpc/mm/pgtable.c | 5 -----
> 3 files changed, 9 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
> b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 079211968987..2382fd516f6b 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -619,7 +619,7 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t
> pgprot)
> VM_BUG_ON(pfn >> (64 - PAGE_SHIFT));
> VM_BUG_ON((pfn << PAGE_SHIFT) & ~PTE_RPN_MASK);
>
> - return __pte(((pte_basic_t)pfn << PAGE_SHIFT) | pgprot_val(pgprot));
> + return __pte(((pte_basic_t)pfn << PAGE_SHIFT) | pgprot_val(pgprot) |
> _PAGE_PTE);
> }
>
> static inline unsigned long pte_pfn(pte_t pte)
> @@ -655,11 +655,6 @@ static inline pte_t pte_mkexec(pte_t pte)
> return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_EXEC));
> }
>
> -static inline pte_t pte_mkpte(pte_t pte)
> -{
> - return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_PTE));
> -}
> -
> static inline pte_t pte_mkwrite(pte_t pte)
> {
> /*
> @@ -823,6 +818,14 @@ static inline int pte_none(pte_t pte)
> static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte, int percpu)
> {
> +
> + VM_WARN_ON(!(pte_raw(pte) & cpu_to_be64(_PAGE_PTE)));
> + /*
> + * Keep the _PAGE_PTE added till we are sure we handle _PAGE_PTE
> + * in all the callers.
> + */
> + pte = __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_PTE));
> +
> if (radix_enabled())
> return radix__set_pte_at(mm, addr, ptep, pte, percpu);
> return hash__set_pte_at(mm, addr, ptep, pte, percpu);
> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h
> b/arch/powerpc/include/asm/nohash/pgtable.h
> index 4b7c3472eab1..6277e7596ae5 100644
> --- a/arch/powerpc/include/asm/nohash/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
> @@ -140,11 +140,6 @@ static inline pte_t pte_mkold(pte_t pte)
> return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
> }
>
> -static inline pte_t pte_mkpte(pte_t pte)
> -{
> - return pte;
> -}
> -
> static inline pte_t pte_mkspecial(pte_t pte)
> {
> return __pte(pte_val(pte) | _PAGE_SPECIAL);
> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
> index 9c0547d77af3..ab57b07ef39a 100644
> --- a/arch/powerpc/mm/pgtable.c
> +++ b/arch/powerpc/mm/pgtable.c
> @@ -184,9 +184,6 @@ void set_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep,
> */
> VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
>
> - /* Add the pte bit when trying to set a pte */
> - pte = pte_mkpte(pte);
> -
> /* Note: mm->context.id might not yet have been assigned as
> * this context might not have been activated yet when this
> * is called.
> @@ -275,8 +272,6 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long
> addr, pte_t *ptep, pte_
> */
> VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
>
> - pte = pte_mkpte(pte);
> -
> pte = set_pte_filter(pte);
>
> val = pte_val(pte);
>
There is one checkpatch.pl warning for this patch.
WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per
line)
#6:
powerpc used to set the pte specific flags in set_pte_at(). This is different
total: 0 errors, 1 warnings, 61 lines checked
