From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1E8201A316A for ; Thu, 24 Apr 2025 09:26:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745486804; cv=none; b=nLT0tf1xqOI5cZoSq5+oKOZCYvewJH60raF/yBktQmr3WDGocEVwIIjSeLdP5qI9hh1t+wmAX8VqBnKyiOlJJONHQMAMUkx2L+4GR4qB3B2Ap9fezUUJioKsT3BkQNcAZfhnvETtsNqqSTMDW8cds56+SIDXtUhD2PxGxV5Dia0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745486804; c=relaxed/simple; bh=lrHXu8JMi5imTFN7e5DKhmGiw9OaDmEYUxvHp6Nu0Rk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DKhhw3RtYoEE3N7qC5IQt77TBlC6kApALng3LkZxA6q6Bi2Rp23XEc70cirBFz8W2yo2kNaAGKxHVI/RPbC3TGMumsgGQuNk23eRoRM0RzwfzeEiVJ+QUABDfYxFKDPUn038zMP+RC+qsosJ2Qor/O7CzWV57NXN6XndB3Gx4j0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 774711063; Thu, 24 Apr 2025 02:26:37 -0700 (PDT) Received: from [10.163.49.106] (unknown [10.163.49.106]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E7F0C3F66E; Thu, 24 Apr 2025 02:26:36 -0700 (PDT) Message-ID: Date: Thu, 24 Apr 2025 14:56:32 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 04/11] arm64/mm: Refactor __set_ptes() and __ptep_get_and_clear() To: Ryan Roberts , Catalin Marinas , Will Deacon , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , David Hildenbrand , "Matthew Wilcox (Oracle)" , Mark Rutland , Alexandre Ghiti , Kevin Brodsky Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250422081822.1836315-1-ryan.roberts@arm.com> <20250422081822.1836315-5-ryan.roberts@arm.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250422081822.1836315-5-ryan.roberts@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/22/25 13:48, Ryan Roberts wrote: > Refactor __set_ptes(), set_pmd_at() and set_pud_at() so that they are > all a thin wrapper around a new common __set_ptes_anysz(), which takes > pgsize parameter. Additionally, refactor __ptep_get_and_clear() and > pmdp_huge_get_and_clear() to use a new common > __ptep_get_and_clear_anysz() which also takes a pgsize parameter. > > These changes will permit the huge_pte API to efficiently batch-set > pgtable entries and take advantage of the future barrier optimizations. > Additionally since the new *_anysz() helpers call the correct > page_table_check_*_set() API based on pgsize, this means that huge_ptes > will be able to get proper coverage. Currently the huge_pte API always > uses the pte API which assumes an entry only covers a single page. > > Reviewed-by: Catalin Marinas > Signed-off-by: Ryan Roberts > --- > arch/arm64/include/asm/pgtable.h | 114 ++++++++++++++++++++----------- > 1 file changed, 73 insertions(+), 41 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index d3b538be1500..d80aa9ba0a16 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -423,23 +423,6 @@ static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr) > return pfn_pte(pte_pfn(pte) + nr, pte_pgprot(pte)); > } > > -static inline void __set_ptes(struct mm_struct *mm, > - unsigned long __always_unused addr, > - pte_t *ptep, pte_t pte, unsigned int nr) > -{ > - page_table_check_ptes_set(mm, ptep, pte, nr); > - __sync_cache_and_tags(pte, nr); > - > - for (;;) { > - __check_safe_pte_update(mm, ptep, pte); > - __set_pte(ptep, pte); > - if (--nr == 0) > - break; > - ptep++; > - pte = pte_advance_pfn(pte, 1); > - } > -} > - > /* > * Hugetlb definitions. > */ > @@ -649,30 +632,62 @@ static inline pgprot_t pud_pgprot(pud_t pud) > return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud)); > } > > -static inline void __set_pte_at(struct mm_struct *mm, > - unsigned long __always_unused addr, > - pte_t *ptep, pte_t pte, unsigned int nr) > +static inline void __set_ptes_anysz(struct mm_struct *mm, pte_t *ptep, > + pte_t pte, unsigned int nr, > + unsigned long pgsize) > { > - __sync_cache_and_tags(pte, nr); > - __check_safe_pte_update(mm, ptep, pte); > - __set_pte(ptep, pte); > + unsigned long stride = pgsize >> PAGE_SHIFT; > + > + switch (pgsize) { > + case PAGE_SIZE: > + page_table_check_ptes_set(mm, ptep, pte, nr); > + break; > + case PMD_SIZE: > + page_table_check_pmds_set(mm, (pmd_t *)ptep, pte_pmd(pte), nr); > + break; > +#ifndef __PAGETABLE_PMD_FOLDED > + case PUD_SIZE: > + page_table_check_puds_set(mm, (pud_t *)ptep, pte_pud(pte), nr); > + break; > +#endif > + default: > + VM_WARN_ON(1); > + } > + > + __sync_cache_and_tags(pte, nr * stride); > + > + for (;;) { > + __check_safe_pte_update(mm, ptep, pte); > + __set_pte(ptep, pte); > + if (--nr == 0) > + break; > + ptep++; > + pte = pte_advance_pfn(pte, stride); > + } > +} > + > +static inline void __set_ptes(struct mm_struct *mm, > + unsigned long __always_unused addr, > + pte_t *ptep, pte_t pte, unsigned int nr) > +{ > + __set_ptes_anysz(mm, ptep, pte, nr, PAGE_SIZE); > } > > -static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, > - pmd_t *pmdp, pmd_t pmd) > +static inline void __set_pmds(struct mm_struct *mm, > + unsigned long __always_unused addr, > + pmd_t *pmdp, pmd_t pmd, unsigned int nr) > { > - page_table_check_pmd_set(mm, pmdp, pmd); > - return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd), > - PMD_SIZE >> PAGE_SHIFT); > + __set_ptes_anysz(mm, (pte_t *)pmdp, pmd_pte(pmd), nr, PMD_SIZE); > } > +#define set_pmd_at(mm, addr, pmdp, pmd) __set_pmds(mm, addr, pmdp, pmd, 1) > > -static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, > - pud_t *pudp, pud_t pud) > +static inline void __set_puds(struct mm_struct *mm, > + unsigned long __always_unused addr, > + pud_t *pudp, pud_t pud, unsigned int nr) > { > - page_table_check_pud_set(mm, pudp, pud); > - return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud), > - PUD_SIZE >> PAGE_SHIFT); > + __set_ptes_anysz(mm, (pte_t *)pudp, pud_pte(pud), nr, PUD_SIZE); > } > +#define set_pud_at(mm, addr, pudp, pud) __set_puds(mm, addr, pudp, pud, 1) > > #define __p4d_to_phys(p4d) __pte_to_phys(p4d_pte(p4d)) > #define __phys_to_p4d_val(phys) __phys_to_pte_val(phys) > @@ -1301,16 +1316,37 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, > } > #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */ > > -static inline pte_t __ptep_get_and_clear(struct mm_struct *mm, > - unsigned long address, pte_t *ptep) > +static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm, > + pte_t *ptep, > + unsigned long pgsize) > { > pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); > > - page_table_check_pte_clear(mm, pte); > + switch (pgsize) { > + case PAGE_SIZE: > + page_table_check_pte_clear(mm, pte); > + break; > + case PMD_SIZE: > + page_table_check_pmd_clear(mm, pte_pmd(pte)); > + break; > +#ifndef __PAGETABLE_PMD_FOLDED > + case PUD_SIZE: > + page_table_check_pud_clear(mm, pte_pud(pte)); > + break; > +#endif > + default: > + VM_WARN_ON(1); > + } > > return pte; > } > > +static inline pte_t __ptep_get_and_clear(struct mm_struct *mm, > + unsigned long address, pte_t *ptep) > +{ > + return __ptep_get_and_clear_anysz(mm, ptep, PAGE_SIZE); > +} > + > static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, unsigned int nr, int full) > { > @@ -1347,11 +1383,7 @@ static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm, > static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, > unsigned long address, pmd_t *pmdp) > { > - pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0)); > - > - page_table_check_pmd_clear(mm, pmd); > - > - return pmd; > + return pte_pmd(__ptep_get_and_clear_anysz(mm, (pte_t *)pmdp, PMD_SIZE)); > } > #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ > Reviewed-by: Anshuman Khandual