This 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 <corbet@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linuxppc-dev@xxxxxxxxxxxxxxxx Cc: linux-s390@xxxxxxxxxxxxxxx Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx Cc: x86@xxxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: linux-doc@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Suggested-by: Mike Rapoport <rppt@xxxxxxxxxx> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> --- Documentation/vm/arch_pgtable_helpers.rst | 258 ++++++++++++++++++++++ mm/debug_vm_pgtable.c | 6 + 2 files changed, 264 insertions(+) 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..cd7609b05446 --- /dev/null +++ b/Documentation/vm/arch_pgtable_helpers.rst @@ -0,0 +1,258 @@ +.. 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_mkinvalid | Invalidates a mapped PMD [1] | +-------------------------------------------------------------------------------- +| 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_mkinvalid | Invalidates a mapped PUD [1] | +-------------------------------------------------------------------------------- +| 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)| +-------------------------------------------------------------------------------- + +[1] https://lore.kernel.org/linux-mm/20181017020930.GN30832@xxxxxxxxxx/ diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 536f3b1b3ad6..a2936938ed78 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -31,6 +31,12 @@ #include <asm/pgalloc.h> #include <asm/tlbflush.h> +/* + * 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
