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Date:   Fri, 8 Mar 2019 10:37:45 +0200
From:   Mike Rapoport <rppt@linux.ibm.com>
To:     Steven Price <steven.price@arm.com>
Cc:     linux-mm@kvack.org, Andy Lutomirski <luto@kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>,
        James Morse <james.morse@arm.com>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will.deacon@arm.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Mark Rutland <Mark.Rutland@arm.com>,
        "Liang, Kan" <kan.liang@linux.intel.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: Re: [PATCH v4 04/19] powerpc: mm: Add p?d_large() definitions
References: <20190306155031.4291-1-steven.price@arm.com>
 <20190306155031.4291-5-steven.price@arm.com>
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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@kernel.crashing.org>
> CC: Paul Mackerras <paulus@samba.org>
> CC: Michael Ellerman <mpe@ellerman.id.au>
> CC: linuxppc-dev@lists.ozlabs.org
> CC: kvm-ppc@vger.kernel.org
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
>  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.