Documentation/mm/arch_pgtable_helpers.rst
Source file repositories/reference/linux-study-clean/Documentation/mm/arch_pgtable_helpers.rst
File Facts
- System
- Linux kernel
- Corpus path
Documentation/mm/arch_pgtable_helpers.rst- Extension
.rst- Size
- 17982 bytes
- Lines
- 251
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
.. SPDX-License-Identifier: GPL-2.0
===============================
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_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_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 of the type specified by |
| | the VMA. |
+---------------------------+--------------------------------------------------+
| pte_mkwrite_novma | Creates a writable PTE, of the conventional type |
| | of writable. |
+---------------------------+--------------------------------------------------+
| pte_wrprotect | Creates a write protected PTE |
+---------------------------+--------------------------------------------------+
| pte_mkspecial | Creates a special 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_clear | Clears a PTE |
+---------------------------+--------------------------------------------------+
| ptep_get_and_clear | Clears and returns PTE |
+---------------------------+--------------------------------------------------+
| ptep_get_and_clear_full | Clears and returns PTE (batched PTE unmap) |
+---------------------------+--------------------------------------------------+Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.