From patchwork Mon May 1 19:27:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vishal Moola X-Patchwork-Id: 13227976 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1243AC7EE21 for ; Mon, 1 May 2023 19:29:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233498AbjEAT3n (ORCPT ); Mon, 1 May 2023 15:29:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233230AbjEAT3V (ORCPT ); Mon, 1 May 2023 15:29:21 -0400 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA2062D66; Mon, 1 May 2023 12:28:50 -0700 (PDT) Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-1aaf21bb42bso11005715ad.2; Mon, 01 May 2023 12:28:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1682969320; x=1685561320; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=B0Od9Inc5y6h3dSbsHmdGR20xSLs7HxIKZ/fFcl7OHg=; b=BSfSX498+nRsOwkOZCv/c3TfiIzHvFrBHqOPXzZnUzdOTpraA1SFYJQ7S9OlNSy+oo SgKJwDZ3qC6C//XEAcYljRcEjgHnyeaNoyhEAyOx7Ys6/3k09Ik8CgCQWIiXukHyuWI8 JqooqMgdLQ1gpcR/L/mcYK+KZEjEg+InGInQqZs8g+xQwi3fiMtnPj+o8uf54dHCG0nD x8PpX8tpE3nfYMsr6vBPGSrBk7IqcdW9rAQJxVfKMF33+mjDorfNig4J/P1XioZbWwxD uXByeI5tsaD8qrYP2W7mncKrp6aQydR1tjw1T6sz0jLjo8cvDXE3/58iahOtRXOU+sGT jXsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682969320; x=1685561320; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=B0Od9Inc5y6h3dSbsHmdGR20xSLs7HxIKZ/fFcl7OHg=; b=QFcsgk46/VstwdeApgLEfJd2t3Z+Y6sQxKg+61pPjBsvX5uctfzpmMxzkI4ZQZ5zVT 2MkWIGKxAIPDMngCDBl1eIM3vQ8OaB7yJOw2cnhxBZfToy+/Opf4ZyR6aMbBF1fBApym olNhobqzoCbln8a9j5X5HAezN+0tSrgqq5ojVBDqRwwAsDUNWvpePULjqepcbNqMIkcR u28OwHt+k/DK59EtnFoDXh/1vlZBPaaR5RWfmdkpHStf4zFRBbgfwV9Rw1Mdu1oh2ULi HHRcNYaMC7pfUNQOuNB+u1gm+08swiwU0IL5aUmQZCp+xSAvdLU1K5i86s08p5yNngVs XLlg== X-Gm-Message-State: AC+VfDy45ac5T7kNelg1PkQZWCTUTIdnNUMFL2gJLdTM8+5J4FKvH+1p rfKEtgPT27druUxsCYkuK18= X-Google-Smtp-Source: ACHHUZ5c/2Ko6MMnlJILdIHFSiqsi7woH2pp9LXJUwyBETBH//ZWHg6e+tUlm1aX3nzTckKQE2QL/Q== X-Received: by 2002:a17:902:d2cf:b0:1aa:ffe1:de13 with SMTP id n15-20020a170902d2cf00b001aaffe1de13mr2810716plc.5.1682969320162; Mon, 01 May 2023 12:28:40 -0700 (PDT) Received: from fedora.hsd1.ca.comcast.net ([2601:644:937f:7f20::9a2c]) by smtp.googlemail.com with ESMTPSA id u8-20020a170902bf4800b0019c13d032d8sm18175622pls.253.2023.05.01.12.28.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 May 2023 12:28:39 -0700 (PDT) From: "Vishal Moola (Oracle)" To: Andrew Morton , Matthew Wilcox Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, "Vishal Moola (Oracle)" Subject: [PATCH v2 04/34] pgtable: Create struct ptdesc Date: Mon, 1 May 2023 12:27:59 -0700 Message-Id: <20230501192829.17086-5-vishal.moola@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230501192829.17086-1-vishal.moola@gmail.com> References: <20230501192829.17086-1-vishal.moola@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Currently, page table information is stored within struct page. As part of simplifying struct page, create struct ptdesc for page table information. Signed-off-by: Vishal Moola (Oracle) --- include/linux/pgtable.h | 52 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 023918666dd4..5e0f51308724 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -989,6 +989,58 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ #endif /* CONFIG_MMU */ + +/** + * struct ptdesc - Memory descriptor for page tables. + * @__page_flags: Same as page flags. Unused for page tables. + * @pt_list: List of used page tables. Used for s390 and x86. + * @_pt_pad_1: Padding that aliases with page's compound head. + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs. + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only. + * @pt_mm: Used for x86 pgds. + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only. + * @ptl: Lock for the page table. + * + * This struct overlays struct page for now. Do not modify without a good + * understanding of the issues. + */ +struct ptdesc { + unsigned long __page_flags; + + union { + struct list_head pt_list; + struct { + unsigned long _pt_pad_1; + pgtable_t pmd_huge_pte; + }; + }; + unsigned long _pt_s390_gaddr; + + union { + struct mm_struct *pt_mm; + atomic_t pt_frag_refcount; + unsigned long index; + }; + +#if ALLOC_SPLIT_PTLOCKS + spinlock_t *ptl; +#else + spinlock_t ptl; +#endif +}; + +#define TABLE_MATCH(pg, pt) \ + static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt)) +TABLE_MATCH(flags, __page_flags); +TABLE_MATCH(compound_head, pt_list); +TABLE_MATCH(compound_head, _pt_pad_1); +TABLE_MATCH(pmd_huge_pte, pmd_huge_pte); +TABLE_MATCH(mapping, _pt_s390_gaddr); +TABLE_MATCH(pt_mm, pt_mm); +TABLE_MATCH(ptl, ptl); +#undef TABLE_MATCH +static_assert(sizeof(struct ptdesc) <= sizeof(struct page)); + /* * No-op macros that just return the current protection value. Defined here * because these macros can be used even if CONFIG_MMU is not defined.