cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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arch_pgtable_helpers.rst (18660B)

      1.. SPDX-License-Identifier: GPL-2.0
      2
      3.. _arch_page_table_helpers:
      4
      5===============================
      6Architecture Page Table Helpers
      7===============================
      8
      9Generic MM expects architectures (with MMU) to provide helpers to create, access
     10and modify page table entries at various level for different memory functions.
     11These page table helpers need to conform to a common semantics across platforms.
     12Following tables describe the expected semantics which can also be tested during
     13boot via CONFIG_DEBUG_VM_PGTABLE option. All future changes in here or the debug
     14test need to be in sync.
     15
     16
     17PTE Page Table Helpers
     18======================
     19
     20+---------------------------+--------------------------------------------------+
     21| pte_same                  | Tests whether both PTE entries are the same      |
     22+---------------------------+--------------------------------------------------+
     23| pte_bad                   | Tests a non-table mapped PTE                     |
     24+---------------------------+--------------------------------------------------+
     25| pte_present               | Tests a valid mapped PTE                         |
     26+---------------------------+--------------------------------------------------+
     27| pte_young                 | Tests a young PTE                                |
     28+---------------------------+--------------------------------------------------+
     29| pte_dirty                 | Tests a dirty PTE                                |
     30+---------------------------+--------------------------------------------------+
     31| pte_write                 | Tests a writable PTE                             |
     32+---------------------------+--------------------------------------------------+
     33| pte_special               | Tests a special PTE                              |
     34+---------------------------+--------------------------------------------------+
     35| pte_protnone              | Tests a PROT_NONE PTE                            |
     36+---------------------------+--------------------------------------------------+
     37| pte_devmap                | Tests a ZONE_DEVICE mapped PTE                   |
     38+---------------------------+--------------------------------------------------+
     39| pte_soft_dirty            | Tests a soft dirty PTE                           |
     40+---------------------------+--------------------------------------------------+
     41| pte_swp_soft_dirty        | Tests a soft dirty swapped PTE                   |
     42+---------------------------+--------------------------------------------------+
     43| pte_mkyoung               | Creates a young PTE                              |
     44+---------------------------+--------------------------------------------------+
     45| pte_mkold                 | Creates an old PTE                               |
     46+---------------------------+--------------------------------------------------+
     47| pte_mkdirty               | Creates a dirty PTE                              |
     48+---------------------------+--------------------------------------------------+
     49| pte_mkclean               | Creates a clean PTE                              |
     50+---------------------------+--------------------------------------------------+
     51| pte_mkwrite               | Creates a writable PTE                           |
     52+---------------------------+--------------------------------------------------+
     53| pte_wrprotect             | Creates a write protected PTE                    |
     54+---------------------------+--------------------------------------------------+
     55| pte_mkspecial             | Creates a special PTE                            |
     56+---------------------------+--------------------------------------------------+
     57| pte_mkdevmap              | Creates a ZONE_DEVICE mapped PTE                 |
     58+---------------------------+--------------------------------------------------+
     59| pte_mksoft_dirty          | Creates a soft dirty PTE                         |
     60+---------------------------+--------------------------------------------------+
     61| pte_clear_soft_dirty      | Clears a soft dirty PTE                          |
     62+---------------------------+--------------------------------------------------+
     63| pte_swp_mksoft_dirty      | Creates a soft dirty swapped PTE                 |
     64+---------------------------+--------------------------------------------------+
     65| pte_swp_clear_soft_dirty  | Clears a soft dirty swapped PTE                  |
     66+---------------------------+--------------------------------------------------+
     67| pte_mknotpresent          | Invalidates a mapped PTE                         |
     68+---------------------------+--------------------------------------------------+
     69| ptep_clear                | Clears a PTE                                     |
     70+---------------------------+--------------------------------------------------+
     71| ptep_get_and_clear        | Clears and returns PTE                           |
     72+---------------------------+--------------------------------------------------+
     73| ptep_get_and_clear_full   | Clears and returns PTE (batched PTE unmap)       |
     74+---------------------------+--------------------------------------------------+
     75| ptep_test_and_clear_young | Clears young from a PTE                          |
     76+---------------------------+--------------------------------------------------+
     77| ptep_set_wrprotect        | Converts into a write protected PTE              |
     78+---------------------------+--------------------------------------------------+
     79| ptep_set_access_flags     | Converts into a more permissive PTE              |
     80+---------------------------+--------------------------------------------------+
     81
     82
     83PMD Page Table Helpers
     84======================
     85
     86+---------------------------+--------------------------------------------------+
     87| pmd_same                  | Tests whether both PMD entries are the same      |
     88+---------------------------+--------------------------------------------------+
     89| pmd_bad                   | Tests a non-table mapped PMD                     |
     90+---------------------------+--------------------------------------------------+
     91| pmd_leaf                  | Tests a leaf mapped PMD                          |
     92+---------------------------+--------------------------------------------------+
     93| pmd_huge                  | Tests a HugeTLB mapped PMD                       |
     94+---------------------------+--------------------------------------------------+
     95| pmd_trans_huge            | Tests a Transparent Huge Page (THP) at PMD       |
     96+---------------------------+--------------------------------------------------+
     97| pmd_present               | Tests a valid mapped PMD                         |
     98+---------------------------+--------------------------------------------------+
     99| pmd_young                 | Tests a young PMD                                |
    100+---------------------------+--------------------------------------------------+
    101| pmd_dirty                 | Tests a dirty PMD                                |
    102+---------------------------+--------------------------------------------------+
    103| pmd_write                 | Tests a writable PMD                             |
    104+---------------------------+--------------------------------------------------+
    105| pmd_special               | Tests a special PMD                              |
    106+---------------------------+--------------------------------------------------+
    107| pmd_protnone              | Tests a PROT_NONE PMD                            |
    108+---------------------------+--------------------------------------------------+
    109| pmd_devmap                | Tests a ZONE_DEVICE mapped PMD                   |
    110+---------------------------+--------------------------------------------------+
    111| pmd_soft_dirty            | Tests a soft dirty PMD                           |
    112+---------------------------+--------------------------------------------------+
    113| pmd_swp_soft_dirty        | Tests a soft dirty swapped PMD                   |
    114+---------------------------+--------------------------------------------------+
    115| pmd_mkyoung               | Creates a young PMD                              |
    116+---------------------------+--------------------------------------------------+
    117| pmd_mkold                 | Creates an old PMD                               |
    118+---------------------------+--------------------------------------------------+
    119| pmd_mkdirty               | Creates a dirty PMD                              |
    120+---------------------------+--------------------------------------------------+
    121| pmd_mkclean               | Creates a clean PMD                              |
    122+---------------------------+--------------------------------------------------+
    123| pmd_mkwrite               | Creates a writable PMD                           |
    124+---------------------------+--------------------------------------------------+
    125| pmd_wrprotect             | Creates a write protected PMD                    |
    126+---------------------------+--------------------------------------------------+
    127| pmd_mkspecial             | Creates a special PMD                            |
    128+---------------------------+--------------------------------------------------+
    129| pmd_mkdevmap              | Creates a ZONE_DEVICE mapped PMD                 |
    130+---------------------------+--------------------------------------------------+
    131| pmd_mksoft_dirty          | Creates a soft dirty PMD                         |
    132+---------------------------+--------------------------------------------------+
    133| pmd_clear_soft_dirty      | Clears a soft dirty PMD                          |
    134+---------------------------+--------------------------------------------------+
    135| pmd_swp_mksoft_dirty      | Creates a soft dirty swapped PMD                 |
    136+---------------------------+--------------------------------------------------+
    137| pmd_swp_clear_soft_dirty  | Clears a soft dirty swapped PMD                  |
    138+---------------------------+--------------------------------------------------+
    139| pmd_mkinvalid             | Invalidates a mapped PMD [1]                     |
    140+---------------------------+--------------------------------------------------+
    141| pmd_set_huge              | Creates a PMD huge mapping                       |
    142+---------------------------+--------------------------------------------------+
    143| pmd_clear_huge            | Clears a PMD huge mapping                        |
    144+---------------------------+--------------------------------------------------+
    145| pmdp_get_and_clear        | Clears a PMD                                     |
    146+---------------------------+--------------------------------------------------+
    147| pmdp_get_and_clear_full   | Clears a PMD                                     |
    148+---------------------------+--------------------------------------------------+
    149| pmdp_test_and_clear_young | Clears young from a PMD                          |
    150+---------------------------+--------------------------------------------------+
    151| pmdp_set_wrprotect        | Converts into a write protected PMD              |
    152+---------------------------+--------------------------------------------------+
    153| pmdp_set_access_flags     | Converts into a more permissive PMD              |
    154+---------------------------+--------------------------------------------------+
    155
    156
    157PUD Page Table Helpers
    158======================
    159
    160+---------------------------+--------------------------------------------------+
    161| pud_same                  | Tests whether both PUD entries are the same      |
    162+---------------------------+--------------------------------------------------+
    163| pud_bad                   | Tests a non-table mapped PUD                     |
    164+---------------------------+--------------------------------------------------+
    165| pud_leaf                  | Tests a leaf mapped PUD                          |
    166+---------------------------+--------------------------------------------------+
    167| pud_huge                  | Tests a HugeTLB mapped PUD                       |
    168+---------------------------+--------------------------------------------------+
    169| pud_trans_huge            | Tests a Transparent Huge Page (THP) at PUD       |
    170+---------------------------+--------------------------------------------------+
    171| pud_present               | Tests a valid mapped PUD                         |
    172+---------------------------+--------------------------------------------------+
    173| pud_young                 | Tests a young PUD                                |
    174+---------------------------+--------------------------------------------------+
    175| pud_dirty                 | Tests a dirty PUD                                |
    176+---------------------------+--------------------------------------------------+
    177| pud_write                 | Tests a writable PUD                             |
    178+---------------------------+--------------------------------------------------+
    179| pud_devmap                | Tests a ZONE_DEVICE mapped PUD                   |
    180+---------------------------+--------------------------------------------------+
    181| pud_mkyoung               | Creates a young PUD                              |
    182+---------------------------+--------------------------------------------------+
    183| pud_mkold                 | Creates an old PUD                               |
    184+---------------------------+--------------------------------------------------+
    185| pud_mkdirty               | Creates a dirty PUD                              |
    186+---------------------------+--------------------------------------------------+
    187| pud_mkclean               | Creates a clean PUD                              |
    188+---------------------------+--------------------------------------------------+
    189| pud_mkwrite               | Creates a writable PUD                           |
    190+---------------------------+--------------------------------------------------+
    191| pud_wrprotect             | Creates a write protected PUD                    |
    192+---------------------------+--------------------------------------------------+
    193| pud_mkdevmap              | Creates a ZONE_DEVICE mapped PUD                 |
    194+---------------------------+--------------------------------------------------+
    195| pud_mkinvalid             | Invalidates a mapped PUD [1]                     |
    196+---------------------------+--------------------------------------------------+
    197| pud_set_huge              | Creates a PUD huge mapping                       |
    198+---------------------------+--------------------------------------------------+
    199| pud_clear_huge            | Clears a PUD huge mapping                        |
    200+---------------------------+--------------------------------------------------+
    201| pudp_get_and_clear        | Clears a PUD                                     |
    202+---------------------------+--------------------------------------------------+
    203| pudp_get_and_clear_full   | Clears a PUD                                     |
    204+---------------------------+--------------------------------------------------+
    205| pudp_test_and_clear_young | Clears young from a PUD                          |
    206+---------------------------+--------------------------------------------------+
    207| pudp_set_wrprotect        | Converts into a write protected PUD              |
    208+---------------------------+--------------------------------------------------+
    209| pudp_set_access_flags     | Converts into a more permissive PUD              |
    210+---------------------------+--------------------------------------------------+
    211
    212
    213HugeTLB Page Table Helpers
    214==========================
    215
    216+---------------------------+--------------------------------------------------+
    217| pte_huge                  | Tests a HugeTLB                                  |
    218+---------------------------+--------------------------------------------------+
    219| pte_mkhuge                | Creates a HugeTLB                                |
    220+---------------------------+--------------------------------------------------+
    221| huge_pte_dirty            | Tests a dirty HugeTLB                            |
    222+---------------------------+--------------------------------------------------+
    223| huge_pte_write            | Tests a writable HugeTLB                         |
    224+---------------------------+--------------------------------------------------+
    225| huge_pte_mkdirty          | Creates a dirty HugeTLB                          |
    226+---------------------------+--------------------------------------------------+
    227| huge_pte_mkwrite          | Creates a writable HugeTLB                       |
    228+---------------------------+--------------------------------------------------+
    229| huge_pte_wrprotect        | Creates a write protected HugeTLB                |
    230+---------------------------+--------------------------------------------------+
    231| huge_ptep_get_and_clear   | Clears a HugeTLB                                 |
    232+---------------------------+--------------------------------------------------+
    233| huge_ptep_set_wrprotect   | Converts into a write protected HugeTLB          |
    234+---------------------------+--------------------------------------------------+
    235| huge_ptep_set_access_flags  | Converts into a more permissive HugeTLB        |
    236+---------------------------+--------------------------------------------------+
    237
    238
    239SWAP Page Table Helpers
    240========================
    241
    242+---------------------------+--------------------------------------------------+
    243| __pte_to_swp_entry        | Creates a swapped entry (arch) from a mapped PTE |
    244+---------------------------+--------------------------------------------------+
    245| __swp_to_pte_entry        | Creates a mapped PTE from a swapped entry (arch) |
    246+---------------------------+--------------------------------------------------+
    247| __pmd_to_swp_entry        | Creates a swapped entry (arch) from a mapped PMD |
    248+---------------------------+--------------------------------------------------+
    249| __swp_to_pmd_entry        | Creates a mapped PMD from a swapped entry (arch) |
    250+---------------------------+--------------------------------------------------+
    251| is_migration_entry        | Tests a migration (read or write) swapped entry  |
    252+-------------------------------+----------------------------------------------+
    253| is_writable_migration_entry   | Tests a write migration swapped entry        |
    254+-------------------------------+----------------------------------------------+
    255| make_readable_migration_entry | Creates a read migration swapped entry       |
    256+-------------------------------+----------------------------------------------+
    257| make_writable_migration_entry | Creates a write migration swapped entry      |
    258+-------------------------------+----------------------------------------------+
    259
    260[1] https://lore.kernel.org/linux-mm/20181017020930.GN30832@redhat.com/