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 32A36763EE for ; Wed, 8 May 2024 09:43:50 +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=1715161433; cv=none; b=KXzWxZgmXTmeNrtH5zQpV87TLtFLQ1Xmk1wxmSjR7IEAKsMtNn1W562eJCbhHVoAwqlrvc4Pw+bBLg77L8wNZqeu1t9iPFt1e1Yd5xzofxYxARLum5KZUpAYk0A7Baxssl2DUShI9kTJPVXZYe78i1OtyDZTSbhsYMfQxuUqc/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715161433; c=relaxed/simple; bh=G0QrYEbGF42FSBqhiwAk8mh4Z+JPS6Ht2fHUStLzhqU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=u9h3LbKgiIbEqyFp42J2H/JB5dJO+NeO+PS3xfFIQGRMXDJls0hpqHKJT7bZHfb5KSE/3PrwSejFwRf0RT4RX/usWOGGFFv3KukmsY7EXRRumIVI4vuUXt0OL9ta1pRdHhpAK0muocU+NF8Tzu421JHtU6QFe/fc537g3AM6e44= 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 282E11063; Wed, 8 May 2024 02:44:16 -0700 (PDT) Received: from [10.163.34.220] (unknown [10.163.34.220]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5A5533F6A8; Wed, 8 May 2024 02:43:45 -0700 (PDT) Message-ID: Date: Wed, 8 May 2024 15:13:48 +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 1/4] arm64/mm: generalize PMD_PRESENT_INVALID for all levels Content-Language: en-US To: Ryan Roberts , Catalin Marinas , Will Deacon , Joey Gouly , Ard Biesheuvel , Mark Rutland , David Hildenbrand , Peter Xu , Mike Rapoport , Shivansh Vij Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20240503144604.151095-1-ryan.roberts@arm.com> <20240503144604.151095-2-ryan.roberts@arm.com> From: Anshuman Khandual In-Reply-To: <20240503144604.151095-2-ryan.roberts@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/3/24 20:15, Ryan Roberts wrote: > As preparation for the next patch, which frees up the PTE_PROT_NONE > present pte and swap pte bit, generalize PMD_PRESENT_INVALID to > PTE_PRESENT_INVALID. This will then be used to mark PROT_NONE ptes (and > entries at any other level) in the next patch. > > While we're at it, fix up the swap pte format comment to include > PTE_PRESENT_INVALID. This is not new, it just wasn't previously > documented. > > Reviewed-by: Catalin Marinas > Signed-off-by: Ryan Roberts Reviewed-by: Anshuman Khandual > --- > arch/arm64/include/asm/pgtable-prot.h | 8 ++++---- > arch/arm64/include/asm/pgtable.h | 21 ++++++++++++--------- > 2 files changed, 16 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index dd9ee67d1d87..cdbf51eef7a6 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -21,11 +21,11 @@ > #define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */ > > /* > - * This bit indicates that the entry is present i.e. pmd_page() > - * still points to a valid huge page in memory even if the pmd > - * has been invalidated. > + * PTE_PRESENT_INVALID=1 & PTE_VALID=0 indicates that the pte's fields should be > + * interpreted according to the HW layout by SW but any attempted HW access to > + * the address will result in a fault. pte_present() returns true. > */ > -#define PMD_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PMD_SECT_VALID */ > +#define PTE_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PTE_VALID */ > > #define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) > #define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index afdd56d26ad7..7156c940ac4f 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -132,6 +132,8 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) > #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) > > #define pte_valid(pte) (!!(pte_val(pte) & PTE_VALID)) > +#define pte_present_invalid(pte) \ > + ((pte_val(pte) & (PTE_VALID | PTE_PRESENT_INVALID)) == PTE_PRESENT_INVALID) > /* > * Execute-only user mappings do not have the PTE_USER bit set. All valid > * kernel mappings have the PTE_UXN bit set. > @@ -261,6 +263,13 @@ static inline pte_t pte_mkpresent(pte_t pte) > return set_pte_bit(pte, __pgprot(PTE_VALID)); > } > > +static inline pte_t pte_mkinvalid(pte_t pte) > +{ > + pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID)); > + pte = clear_pte_bit(pte, __pgprot(PTE_VALID)); > + return pte; > +} > + > static inline pmd_t pmd_mkcont(pmd_t pmd) > { > return __pmd(pmd_val(pmd) | PMD_SECT_CONT); > @@ -478,7 +487,7 @@ static inline int pmd_protnone(pmd_t pmd) > } > #endif > > -#define pmd_present_invalid(pmd) (!!(pmd_val(pmd) & PMD_PRESENT_INVALID)) > +#define pmd_present_invalid(pmd) pte_present_invalid(pmd_pte(pmd)) > > static inline int pmd_present(pmd_t pmd) > { > @@ -508,14 +517,7 @@ static inline int pmd_trans_huge(pmd_t pmd) > #define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) > #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) > #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) > - > -static inline pmd_t pmd_mkinvalid(pmd_t pmd) > -{ > - pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID)); > - pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID)); > - > - return pmd; > -} > +#define pmd_mkinvalid(pmd) pte_pmd(pte_mkinvalid(pmd_pte(pmd))) > > #define pmd_thp_or_huge(pmd) (pmd_huge(pmd) || pmd_trans_huge(pmd)) > > @@ -1251,6 +1253,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > * bits 3-7: swap type > * bits 8-57: swap offset > * bit 58: PTE_PROT_NONE (must be zero) > + * bit 59: PTE_PRESENT_INVALID (must be zero) > */ > #define __SWP_TYPE_SHIFT 3 > #define __SWP_TYPE_BITS 5