Re: [PATCH v4 04/19] powerpc: mm: Add p?d_large() definitions

From: Mike Rapoport
Date: Fri Mar 08 2019 - 03:38:03 EST


On Wed, Mar 06, 2019 at 03:50:16PM +0000, Steven Price wrote:
> walk_page_range() is going to be allowed to walk page tables other than
> those of user space. For this it needs to know when it has reached a
> 'leaf' entry in the page tables. This information is provided by the
> p?d_large() functions/macros.
>
> For powerpc pmd_large() was already implemented, so hoist it out of the
> CONFIG_TRANSPARENT_HUGEPAGE condition and implement the other levels.
>
> Also since we now have a pmd_large always implemented we can drop the
> pmd_is_leaf() function.
>
> CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> CC: Paul Mackerras <paulus@xxxxxxxxx>
> CC: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> CC: linuxppc-dev@xxxxxxxxxxxxxxxx
> CC: kvm-ppc@xxxxxxxxxxxxxxx
> Signed-off-by: Steven Price <steven.price@xxxxxxx>
> ---
> arch/powerpc/include/asm/book3s/64/pgtable.h | 30 ++++++++++++++------

There is one more definition of pmd_large() in
arch/powerpc/include/asm/pgtable.h

> arch/powerpc/kvm/book3s_64_mmu_radix.c | 12 ++------
> 2 files changed, 24 insertions(+), 18 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index c9bfe526ca9d..c4b29caf2a3b 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -907,6 +907,12 @@ static inline int pud_present(pud_t pud)
> return (pud_raw(pud) & cpu_to_be64(_PAGE_PRESENT));
> }
>
> +#define pud_large pud_large
> +static inline int pud_large(pud_t pud)
> +{
> + return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
> +}
> +
> extern struct page *pud_page(pud_t pud);
> extern struct page *pmd_page(pmd_t pmd);
> static inline pte_t pud_pte(pud_t pud)
> @@ -954,6 +960,12 @@ static inline int pgd_present(pgd_t pgd)
> return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT));
> }
>
> +#define pgd_large pgd_large
> +static inline int pgd_large(pgd_t pgd)
> +{
> + return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE));
> +}
> +
> static inline pte_t pgd_pte(pgd_t pgd)
> {
> return __pte_raw(pgd_raw(pgd));
> @@ -1107,6 +1119,15 @@ static inline bool pmd_access_permitted(pmd_t pmd, bool write)
> return pte_access_permitted(pmd_pte(pmd), write);
> }
>
> +#define pmd_large pmd_large
> +/*
> + * returns true for pmd migration entries, THP, devmap, hugetlb
> + */
> +static inline int pmd_large(pmd_t pmd)
> +{
> + return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
> +}
> +
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
> extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
> @@ -1133,15 +1154,6 @@ pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp,
> return hash__pmd_hugepage_update(mm, addr, pmdp, clr, set);
> }
>
> -/*
> - * returns true for pmd migration entries, THP, devmap, hugetlb
> - * But compile time dependent on THP config
> - */
> -static inline int pmd_large(pmd_t pmd)
> -{
> - return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
> -}
> -
> static inline pmd_t pmd_mknotpresent(pmd_t pmd)
> {
> return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> index 1b821c6efdef..040db20ac2ab 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> @@ -363,12 +363,6 @@ static void kvmppc_pte_free(pte_t *ptep)
> kmem_cache_free(kvm_pte_cache, ptep);
> }
>
> -/* Like pmd_huge() and pmd_large(), but works regardless of config options */
> -static inline int pmd_is_leaf(pmd_t pmd)
> -{
> - return !!(pmd_val(pmd) & _PAGE_PTE);
> -}
> -
> static pmd_t *kvmppc_pmd_alloc(void)
> {
> return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
> @@ -455,7 +449,7 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
> for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
> if (!pmd_present(*p))
> continue;
> - if (pmd_is_leaf(*p)) {
> + if (pmd_large(*p)) {
> if (full) {
> pmd_clear(p);
> } else {
> @@ -588,7 +582,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
> else if (level <= 1)
> new_pmd = kvmppc_pmd_alloc();
>
> - if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
> + if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_large(*pmd)))
> new_ptep = kvmppc_pte_alloc();
>
> /* Check if we might have been invalidated; let the guest retry if so */
> @@ -657,7 +651,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
> new_pmd = NULL;
> }
> pmd = pmd_offset(pud, gpa);
> - if (pmd_is_leaf(*pmd)) {
> + if (pmd_large(*pmd)) {
> unsigned long lgpa = gpa & PMD_MASK;
>
> /* Check if we raced and someone else has set the same thing */
> --
> 2.20.1
>

--
Sincerely yours,
Mike.