From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FB4FC54FCF for ; Tue, 24 Mar 2020 05:23:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E710D207FF for ; Tue, 24 Mar 2020 05:23:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727376AbgCXFXk (ORCPT ); Tue, 24 Mar 2020 01:23:40 -0400 Received: from foss.arm.com ([217.140.110.172]:57602 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725923AbgCXFXj (ORCPT ); Tue, 24 Mar 2020 01:23:39 -0400 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 CA3067FA; Mon, 23 Mar 2020 22:23:38 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.1.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id F2AC73F7C3; Mon, 23 Mar 2020 22:27:40 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org Cc: christophe.leroy@c-s.fr, Anshuman Khandual , Jonathan Corbet , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 3/3] Documentation/mm: Add descriptions for arch page table helpers Date: Tue, 24 Mar 2020 10:52:55 +0530 Message-Id: <1585027375-9997-4-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1585027375-9997-1-git-send-email-anshuman.khandual@arm.com> References: <1585027375-9997-1-git-send-email-anshuman.khandual@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This removes existing description from the test and instead adds a specific description file for all arch page table helpers which is in sync with the semantics being tested via CONFIG_DEBUG_VM_PGTABLE. All future changes either to these descriptions here or the debug test should always remain in sync. Cc: Jonathan Corbet Cc: Andrew Morton Cc: linux-doc@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Suggested-by: Mike Rapoport Signed-off-by: Anshuman Khandual --- Documentation/vm/arch_pgtable_helpers.rst | 256 ++++++++++++++++++++++ mm/debug_vm_pgtable.c | 13 +- 2 files changed, 259 insertions(+), 10 deletions(-) create mode 100644 Documentation/vm/arch_pgtable_helpers.rst diff --git a/Documentation/vm/arch_pgtable_helpers.rst b/Documentation/vm/arch_pgtable_helpers.rst new file mode 100644 index 000000000000..1fc8a1d8932a --- /dev/null +++ b/Documentation/vm/arch_pgtable_helpers.rst @@ -0,0 +1,256 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _arch_page_table_helpers: + +=============================== +Architecture Page Table Helpers +=============================== + +Generic MM expects architectures (with MMU) to provide helpers to create, access +and modify page table entries at various level for different memory functions. +These page table helpers need to conform to a common semantics across platforms. +Following tables describe the expected semantics which can also be tested during +boot via CONFIG_DEBUG_VM_PGTABLE option. All future changes in here or the debug +test need to be in sync. + +====================== +PTE Page Table Helpers +====================== + +-------------------------------------------------------------------------------- +| pte_same | Tests whether both PTE entries are the same | +-------------------------------------------------------------------------------- +| pte_bad | Tests a non-table mapped PTE | +-------------------------------------------------------------------------------- +| pte_present | Tests a valid mapped PTE | +-------------------------------------------------------------------------------- +| pte_young | Tests a young PTE | +-------------------------------------------------------------------------------- +| pte_dirty | Tests a dirty PTE | +-------------------------------------------------------------------------------- +| pte_write | Tests a writable PTE | +-------------------------------------------------------------------------------- +| pte_special | Tests a special PTE | +-------------------------------------------------------------------------------- +| pte_protnone | Tests a PROT_NONE PTE | +-------------------------------------------------------------------------------- +| pte_devmap | Tests a ZONE_DEVICE mapped PTE | +-------------------------------------------------------------------------------- +| pte_soft_dirty | Tests a soft dirty PTE | +-------------------------------------------------------------------------------- +| pte_swp_soft_dirty | Tests a soft dirty swapped PTE | +-------------------------------------------------------------------------------- +| pte_mkyoung | Creates a young PTE | +-------------------------------------------------------------------------------- +| pte_mkold | Creates an old PTE | +-------------------------------------------------------------------------------- +| pte_mkdirty | Creates a dirty PTE | +-------------------------------------------------------------------------------- +| pte_mkclean | Creates a clean PTE | +-------------------------------------------------------------------------------- +| pte_mkwrite | Creates a writable PTE | +-------------------------------------------------------------------------------- +| pte_mkwrprotect | Creates a write protected PTE | +-------------------------------------------------------------------------------- +| pte_mkspecial | Creates a special PTE | +-------------------------------------------------------------------------------- +| pte_mkdevmap | Creates a ZONE_DEVICE mapped PTE | +-------------------------------------------------------------------------------- +| pte_mksoft_dirty | Creates a soft dirty PTE | +-------------------------------------------------------------------------------- +| pte_clear_soft_dirty | Clears a soft dirty PTE | +-------------------------------------------------------------------------------- +| pte_swp_mksoft_dirty | Creates a soft dirty swapped PTE | +-------------------------------------------------------------------------------- +| pte_swp_clear_soft_dirty | Clears a soft dirty swapped PTE | +-------------------------------------------------------------------------------- +| pte_mknotpresent | Invalidates a mapped PTE | +-------------------------------------------------------------------------------- +| ptep_get_and_clear | Clears a PTE | +-------------------------------------------------------------------------------- +| ptep_get_and_clear_full | Clears a PTE | +-------------------------------------------------------------------------------- +| ptep_test_and_clear_young | Clears young from a PTE | +-------------------------------------------------------------------------------- +| ptep_set_wrprotect | Converts into a write protected PTE | +-------------------------------------------------------------------------------- +| ptep_set_access_flags | Converts into a more permissive PTE | +-------------------------------------------------------------------------------- + +====================== +PMD Page Table Helpers +====================== + +-------------------------------------------------------------------------------- +| pmd_same | Tests whether both PMD entries are the same | +-------------------------------------------------------------------------------- +| pmd_bad | Tests a non-table mapped PMD | +-------------------------------------------------------------------------------- +| pmd_leaf | Tests a leaf mapped PMD | +-------------------------------------------------------------------------------- +| pmd_huge | Tests a HugeTLB mapped PMD | +-------------------------------------------------------------------------------- +| pmd_trans_huge | Tests a Transparent Huge Page (THP) at PMD | +-------------------------------------------------------------------------------- +| pmd_present | Tests a valid mapped PMD | +-------------------------------------------------------------------------------- +| pmd_young | Tests a young PMD | +-------------------------------------------------------------------------------- +| pmd_dirty | Tests a dirty PMD | +-------------------------------------------------------------------------------- +| pmd_write | Tests a writable PMD | +-------------------------------------------------------------------------------- +| pmd_special | Tests a special PMD | +-------------------------------------------------------------------------------- +| pmd_protnone | Tests a PROT_NONE PMD | +-------------------------------------------------------------------------------- +| pmd_devmap | Tests a ZONE_DEVICE mapped PMD | +-------------------------------------------------------------------------------- +| pmd_soft_dirty | Tests a soft dirty PMD | +-------------------------------------------------------------------------------- +| pmd_swp_soft_dirty | Tests a soft dirty swapped PMD | +-------------------------------------------------------------------------------- +| pmd_mkyoung | Creates a young PMD | +-------------------------------------------------------------------------------- +| pmd_mkold | Creates an old PMD | +-------------------------------------------------------------------------------- +| pmd_mkdirty | Creates a dirty PMD | +-------------------------------------------------------------------------------- +| pmd_mkclean | Creates a clean PMD | +-------------------------------------------------------------------------------- +| pmd_mkwrite | Creates a writable PMD | +-------------------------------------------------------------------------------- +| pmd_mkwrprotect | Creates a write protected PMD | +-------------------------------------------------------------------------------- +| pmd_mkspecial | Creates a special PMD | +-------------------------------------------------------------------------------- +| pmd_mkdevmap | Creates a ZONE_DEVICE mapped PMD | +-------------------------------------------------------------------------------- +| pmd_mksoft_dirty | Creates a soft dirty PMD | +-------------------------------------------------------------------------------- +| pmd_clear_soft_dirty | Clears a soft dirty PMD | +-------------------------------------------------------------------------------- +| pmd_swp_mksoft_dirty | Creates a soft dirty swapped PMD | +-------------------------------------------------------------------------------- +| pmd_swp_clear_soft_dirty | Clears a soft dirty swapped PMD | +-------------------------------------------------------------------------------- +| pmd_mknotpresent | Invalidates a mapped PMD | +-------------------------------------------------------------------------------- +| pmd_set_huge | Creates a PMD huge mapping | +-------------------------------------------------------------------------------- +| pmd_clear_huge | Clears a PMD huge mapping | +-------------------------------------------------------------------------------- +| pmdp_get_and_clear | Clears a PMD | +-------------------------------------------------------------------------------- +| pmdp_get_and_clear_full | Clears a PMD | +-------------------------------------------------------------------------------- +| pmdp_test_and_clear_young | Clears young from a PMD | +-------------------------------------------------------------------------------- +| pmdp_set_wrprotect | Converts into a write protected PMD | +-------------------------------------------------------------------------------- +| pmdp_set_access_flags | Converts into a more permissive PMD | +-------------------------------------------------------------------------------- + +====================== +PUD Page Table Helpers +====================== + +-------------------------------------------------------------------------------- +| pud_same | Tests whether both PUD entries are the same | +-------------------------------------------------------------------------------- +| pud_bad | Tests a non-table mapped PUD | +-------------------------------------------------------------------------------- +| pud_leaf | Tests a leaf mapped PUD | +-------------------------------------------------------------------------------- +| pud_huge | Tests a HugeTLB mapped PUD | +-------------------------------------------------------------------------------- +| pud_trans_huge | Tests a Transparent Huge Page (THP) at PUD | +-------------------------------------------------------------------------------- +| pud_present | Tests a valid mapped PUD | +-------------------------------------------------------------------------------- +| pud_young | Tests a young PUD | +-------------------------------------------------------------------------------- +| pud_dirty | Tests a dirty PUD | +-------------------------------------------------------------------------------- +| pud_write | Tests a writable PUD | +-------------------------------------------------------------------------------- +| pud_devmap | Tests a ZONE_DEVICE mapped PUD | +-------------------------------------------------------------------------------- +| pud_mkyoung | Creates a young PUD | +-------------------------------------------------------------------------------- +| pud_mkold | Creates an old PUD | +-------------------------------------------------------------------------------- +| pud_mkdirty | Creates a dirty PUD | +-------------------------------------------------------------------------------- +| pud_mkclean | Creates a clean PUD | +-------------------------------------------------------------------------------- +| pud_mkwrite | Creates a writable PMD | +-------------------------------------------------------------------------------- +| pud_mkwrprotect | Creates a write protected PMD | +-------------------------------------------------------------------------------- +| pud_mkdevmap | Creates a ZONE_DEVICE mapped PMD | +-------------------------------------------------------------------------------- +| pud_mknotpresent | Invalidates a mapped PUD | +-------------------------------------------------------------------------------- +| pud_set_huge | Creates a PUD huge mapping | +-------------------------------------------------------------------------------- +| pud_clear_huge | Clears a PUD huge mapping | +-------------------------------------------------------------------------------- +| pudp_get_and_clear | Clears a PUD | +-------------------------------------------------------------------------------- +| pudp_get_and_clear_full | Clears a PUD | +-------------------------------------------------------------------------------- +| pudp_test_and_clear_young | Clears young from a PUD | +-------------------------------------------------------------------------------- +| pudp_set_wrprotect | Converts into a write protected PUD | +-------------------------------------------------------------------------------- +| pudp_set_access_flags | Converts into a more permissive PUD | +-------------------------------------------------------------------------------- + +========================== +HugeTLB Page Table Helpers +========================== + +-------------------------------------------------------------------------------- +| pte_huge | Tests a HugeTLB | +-------------------------------------------------------------------------------- +| pte_mkhuge | Creates a HugeTLB | +-------------------------------------------------------------------------------- +| huge_pte_dirty | Tests a dirty HugeTLB | +-------------------------------------------------------------------------------- +| huge_pte_write | Tests a writable HugeTLB | +-------------------------------------------------------------------------------- +| huge_pte_mkdirty | Creates a dirty HugeTLB | +-------------------------------------------------------------------------------- +| huge_pte_mkwrite | Creates a writable HugeTLB | +-------------------------------------------------------------------------------- +| huge_pte_mkwrprotect | Creates a write protected HugeTLB | +-------------------------------------------------------------------------------- +| huge_ptep_get_and_clear | Clears a HugeTLB | +-------------------------------------------------------------------------------- +| huge_ptep_set_wrprotect | Converts into a write protected HugeTLB | +-------------------------------------------------------------------------------- +| huge_ptep_set_access_flags | Converts into a more permissive HugeTLB | +-------------------------------------------------------------------------------- + +======================== +SWAP Page Table Helpers +======================== + +-------------------------------------------------------------------------------- +| __pte_to_swp_entry | Creates a swapped entry (arch) from a mapepd PTE | +-------------------------------------------------------------------------------- +| __swp_to_pte_entry | Creates a mapped PTE from a swapped entry (arch) | +-------------------------------------------------------------------------------- +| __pmd_to_swp_entry | Creates a swapped entry (arch) from a mapepd PMD | +-------------------------------------------------------------------------------- +| __swp_to_pmd_entry | Creates a mapped PMD from a swapped entry (arch) | +-------------------------------------------------------------------------------- +| is_migration_entry | Tests a migration (read or write) swapped entry | +-------------------------------------------------------------------------------- +| is_write_migration_entry | Tests a write migration swapped entry | +-------------------------------------------------------------------------------- +| make_migration_entry_read | Converts into read migration swapped entry | +-------------------------------------------------------------------------------- +| make_migration_entry | Creates a migration swapped entry (read or write)| +-------------------------------------------------------------------------------- diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 87b4b495333b..7c210f99a812 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -32,16 +32,9 @@ #include /* - * Basic operations - * - * mkold(entry) = An old and not a young entry - * mkyoung(entry) = A young and not an old entry - * mkdirty(entry) = A dirty and not a clean entry - * mkclean(entry) = A clean and not a dirty entry - * mkwrite(entry) = A write and not a write protected entry - * wrprotect(entry) = A write protected and not a write entry - * pxx_bad(entry) = A mapped and non-table entry - * pxx_same(entry1, entry2) = Both entries hold the exact same value + * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics + * expectations that are being validated here. All future changes in here + * or the documentation need to be in sync. */ #define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC) -- 2.20.1