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_wrprotect 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_wrprotect 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 PUD
pud_wrprotect Creates a write protected PUD
pud_mkdevmap Creates a ZONE_DEVICE mapped PUD
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_wrprotect 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 mapped 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 mapped 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@redhat.com/