1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450145114521453145414551456145714581459146014611462146314641465146614671468146914701471147214731474147514761477147814791480148114821483148414851486148714881489149014911492149314941495149614971498149915001501150215031504150515061507150815091510151115121513151415151516151715181519152015211522152315241525152615271528152915301531153215331534153515361537153815391540154115421543154415451546154715481549155015511552155315541555155615571558155915601561156215631564156515661567156815691570157115721573157415751576157715781579158015811582158315841585158615871588158915901591159215931594159515961597159815991600160116021603160416051606160716081609161016111612161316141615161616171618161916201621162216231624162516261627162816291630163116321633163416351636163716381639164016411642164316441645164616471648164916501651165216531654165516561657165816591660166116621663166416651666166716681669167016711672167316741675167616771678167916801681168216831684168516861687168816891690169116921693169416951696169716981699170017011702170317041705170617071708170917101711171217131714171517161717171817191720172117221723172417251726172717281729173017311732173317341735173617371738173917401741174217431744174517461747 |
- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef _LINUX_PGTABLE_H
- #define _LINUX_PGTABLE_H
- #include <linux/pfn.h>
- #include <asm/pgtable.h>
- #ifndef __ASSEMBLY__
- #ifdef CONFIG_MMU
- #include <linux/mm_types.h>
- #include <linux/bug.h>
- #include <linux/errno.h>
- #include <asm-generic/pgtable_uffd.h>
- #include <linux/page_table_check.h>
- #if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
- defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
- #error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
- #endif
- /*
- * On almost all architectures and configurations, 0 can be used as the
- * upper ceiling to free_pgtables(): on many architectures it has the same
- * effect as using TASK_SIZE. However, there is one configuration which
- * must impose a more careful limit, to avoid freeing kernel pgtables.
- */
- #ifndef USER_PGTABLES_CEILING
- #define USER_PGTABLES_CEILING 0UL
- #endif
- /*
- * This defines the first usable user address. Platforms
- * can override its value with custom FIRST_USER_ADDRESS
- * defined in their respective <asm/pgtable.h>.
- */
- #ifndef FIRST_USER_ADDRESS
- #define FIRST_USER_ADDRESS 0UL
- #endif
- /*
- * This defines the generic helper for accessing PMD page
- * table page. Although platforms can still override this
- * via their respective <asm/pgtable.h>.
- */
- #ifndef pmd_pgtable
- #define pmd_pgtable(pmd) pmd_page(pmd)
- #endif
- /*
- * A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
- *
- * The pXx_index() functions return the index of the entry in the page
- * table page which would control the given virtual address
- *
- * As these functions may be used by the same code for different levels of
- * the page table folding, they are always available, regardless of
- * CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
- * because in such cases PTRS_PER_PxD equals 1.
- */
- static inline unsigned long pte_index(unsigned long address)
- {
- return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
- }
- #define pte_index pte_index
- #ifndef pmd_index
- static inline unsigned long pmd_index(unsigned long address)
- {
- return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
- }
- #define pmd_index pmd_index
- #endif
- #ifndef pud_index
- static inline unsigned long pud_index(unsigned long address)
- {
- return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
- }
- #define pud_index pud_index
- #endif
- #ifndef pgd_index
- /* Must be a compile-time constant, so implement it as a macro */
- #define pgd_index(a) (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
- #endif
- #ifndef pte_offset_kernel
- static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
- {
- return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
- }
- #define pte_offset_kernel pte_offset_kernel
- #endif
- #if defined(CONFIG_HIGHPTE)
- #define pte_offset_map(dir, address) \
- ((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
- pte_index((address)))
- #define pte_unmap(pte) kunmap_atomic((pte))
- #else
- #define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
- #define pte_unmap(pte) ((void)(pte)) /* NOP */
- #endif
- /* Find an entry in the second-level page table.. */
- #ifndef pmd_offset
- static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
- {
- return pud_pgtable(*pud) + pmd_index(address);
- }
- #define pmd_offset pmd_offset
- #endif
- #ifndef pud_offset
- static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
- {
- return p4d_pgtable(*p4d) + pud_index(address);
- }
- #define pud_offset pud_offset
- #endif
- static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
- {
- return (pgd + pgd_index(address));
- };
- /*
- * a shortcut to get a pgd_t in a given mm
- */
- #ifndef pgd_offset
- #define pgd_offset(mm, address) pgd_offset_pgd((mm)->pgd, (address))
- #endif
- /*
- * a shortcut which implies the use of the kernel's pgd, instead
- * of a process's
- */
- #ifndef pgd_offset_k
- #define pgd_offset_k(address) pgd_offset(&init_mm, (address))
- #endif
- /*
- * In many cases it is known that a virtual address is mapped at PMD or PTE
- * level, so instead of traversing all the page table levels, we can get a
- * pointer to the PMD entry in user or kernel page table or translate a virtual
- * address to the pointer in the PTE in the kernel page tables with simple
- * helpers.
- */
- static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
- {
- return pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, va), va), va), va);
- }
- static inline pmd_t *pmd_off_k(unsigned long va)
- {
- return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
- }
- static inline pte_t *virt_to_kpte(unsigned long vaddr)
- {
- pmd_t *pmd = pmd_off_k(vaddr);
- return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr);
- }
- #ifndef pmd_young
- static inline int pmd_young(pmd_t pmd)
- {
- return 0;
- }
- #endif
- #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
- extern int ptep_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep,
- pte_t entry, int dirty);
- #endif
- #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- extern int pmdp_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp,
- pmd_t entry, int dirty);
- extern int pudp_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pud_t *pudp,
- pud_t entry, int dirty);
- #else
- static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp,
- pmd_t entry, int dirty)
- {
- BUILD_BUG();
- return 0;
- }
- static inline int pudp_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pud_t *pudp,
- pud_t entry, int dirty)
- {
- BUILD_BUG();
- return 0;
- }
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #endif
- #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
- static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address,
- pte_t *ptep)
- {
- pte_t pte = *ptep;
- int r = 1;
- if (!pte_young(pte))
- r = 0;
- else
- set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
- return r;
- }
- #endif
- #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
- #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
- static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address,
- pmd_t *pmdp)
- {
- pmd_t pmd = *pmdp;
- int r = 1;
- if (!pmd_young(pmd))
- r = 0;
- else
- set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
- return r;
- }
- #else
- static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address,
- pmd_t *pmdp)
- {
- BUILD_BUG();
- return 0;
- }
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
- #endif
- #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
- int ptep_clear_flush_young(struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep);
- #endif
- #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp);
- #else
- /*
- * Despite relevant to THP only, this API is called from generic rmap code
- * under PageTransHuge(), hence needs a dummy implementation for !THP
- */
- static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp)
- {
- BUILD_BUG();
- return 0;
- }
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #endif
- #ifndef arch_has_hw_nonleaf_pmd_young
- /*
- * Return whether the accessed bit in non-leaf PMD entries is supported on the
- * local CPU.
- */
- static inline bool arch_has_hw_nonleaf_pmd_young(void)
- {
- return IS_ENABLED(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG);
- }
- #endif
- #ifndef arch_has_hw_pte_young
- /*
- * Return whether the accessed bit is supported on the local CPU.
- *
- * This stub assumes accessing through an old PTE triggers a page fault.
- * Architectures that automatically set the access bit should overwrite it.
- */
- static inline bool arch_has_hw_pte_young(void)
- {
- return false;
- }
- #endif
- #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
- static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
- unsigned long address,
- pte_t *ptep)
- {
- pte_t pte = *ptep;
- pte_clear(mm, address, ptep);
- page_table_check_pte_clear(mm, address, pte);
- return pte;
- }
- #endif
- static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep)
- {
- ptep_get_and_clear(mm, addr, ptep);
- }
- #ifndef __HAVE_ARCH_PTEP_GET
- static inline pte_t ptep_get(pte_t *ptep)
- {
- return READ_ONCE(*ptep);
- }
- #endif
- #ifdef CONFIG_GUP_GET_PTE_LOW_HIGH
- /*
- * WARNING: only to be used in the get_user_pages_fast() implementation.
- *
- * With get_user_pages_fast(), we walk down the pagetables without taking any
- * locks. For this we would like to load the pointers atomically, but sometimes
- * that is not possible (e.g. without expensive cmpxchg8b on x86_32 PAE). What
- * we do have is the guarantee that a PTE will only either go from not present
- * to present, or present to not present or both -- it will not switch to a
- * completely different present page without a TLB flush in between; something
- * that we are blocking by holding interrupts off.
- *
- * Setting ptes from not present to present goes:
- *
- * ptep->pte_high = h;
- * smp_wmb();
- * ptep->pte_low = l;
- *
- * And present to not present goes:
- *
- * ptep->pte_low = 0;
- * smp_wmb();
- * ptep->pte_high = 0;
- *
- * We must ensure here that the load of pte_low sees 'l' IFF pte_high sees 'h'.
- * We load pte_high *after* loading pte_low, which ensures we don't see an older
- * value of pte_high. *Then* we recheck pte_low, which ensures that we haven't
- * picked up a changed pte high. We might have gotten rubbish values from
- * pte_low and pte_high, but we are guaranteed that pte_low will not have the
- * present bit set *unless* it is 'l'. Because get_user_pages_fast() only
- * operates on present ptes we're safe.
- */
- static inline pte_t ptep_get_lockless(pte_t *ptep)
- {
- pte_t pte;
- do {
- pte.pte_low = ptep->pte_low;
- smp_rmb();
- pte.pte_high = ptep->pte_high;
- smp_rmb();
- } while (unlikely(pte.pte_low != ptep->pte_low));
- return pte;
- }
- #else /* CONFIG_GUP_GET_PTE_LOW_HIGH */
- /*
- * We require that the PTE can be read atomically.
- */
- static inline pte_t ptep_get_lockless(pte_t *ptep)
- {
- return ptep_get(ptep);
- }
- #endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- #ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
- static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
- unsigned long address,
- pmd_t *pmdp)
- {
- pmd_t pmd = *pmdp;
- pmd_clear(pmdp);
- page_table_check_pmd_clear(mm, address, pmd);
- return pmd;
- }
- #endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
- #ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
- static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
- unsigned long address,
- pud_t *pudp)
- {
- pud_t pud = *pudp;
- pud_clear(pudp);
- page_table_check_pud_clear(mm, address, pud);
- return pud;
- }
- #endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- #ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
- static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp,
- int full)
- {
- return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
- }
- #endif
- #ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
- static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
- unsigned long address, pud_t *pudp,
- int full)
- {
- return pudp_huge_get_and_clear(mm, address, pudp);
- }
- #endif
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
- static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
- unsigned long address, pte_t *ptep,
- int full)
- {
- pte_t pte;
- pte = ptep_get_and_clear(mm, address, ptep);
- return pte;
- }
- #endif
- /*
- * If two threads concurrently fault at the same page, the thread that
- * won the race updates the PTE and its local TLB/Cache. The other thread
- * gives up, simply does nothing, and continues; on architectures where
- * software can update TLB, local TLB can be updated here to avoid next page
- * fault. This function updates TLB only, do nothing with cache or others.
- * It is the difference with function update_mmu_cache.
- */
- #ifndef __HAVE_ARCH_UPDATE_MMU_TLB
- static inline void update_mmu_tlb(struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep)
- {
- }
- #define __HAVE_ARCH_UPDATE_MMU_TLB
- #endif
- /*
- * Some architectures may be able to avoid expensive synchronization
- * primitives when modifications are made to PTE's which are already
- * not present, or in the process of an address space destruction.
- */
- #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
- static inline void pte_clear_not_present_full(struct mm_struct *mm,
- unsigned long address,
- pte_t *ptep,
- int full)
- {
- pte_clear(mm, address, ptep);
- }
- #endif
- #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
- extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
- unsigned long address,
- pte_t *ptep);
- #endif
- #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
- extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
- unsigned long address,
- pmd_t *pmdp);
- extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
- unsigned long address,
- pud_t *pudp);
- #endif
- #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
- struct mm_struct;
- static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
- {
- pte_t old_pte = *ptep;
- set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
- }
- #endif
- /*
- * On some architectures hardware does not set page access bit when accessing
- * memory page, it is responsibility of software setting this bit. It brings
- * out extra page fault penalty to track page access bit. For optimization page
- * access bit can be set during all page fault flow on these arches.
- * To be differentiate with macro pte_mkyoung, this macro is used on platforms
- * where software maintains page access bit.
- */
- #ifndef pte_sw_mkyoung
- static inline pte_t pte_sw_mkyoung(pte_t pte)
- {
- return pte;
- }
- #define pte_sw_mkyoung pte_sw_mkyoung
- #endif
- #ifndef pte_savedwrite
- #define pte_savedwrite pte_write
- #endif
- #ifndef pte_mk_savedwrite
- #define pte_mk_savedwrite pte_mkwrite
- #endif
- #ifndef pte_clear_savedwrite
- #define pte_clear_savedwrite pte_wrprotect
- #endif
- #ifndef pmd_savedwrite
- #define pmd_savedwrite pmd_write
- #endif
- #ifndef pmd_mk_savedwrite
- #define pmd_mk_savedwrite pmd_mkwrite
- #endif
- #ifndef pmd_clear_savedwrite
- #define pmd_clear_savedwrite pmd_wrprotect
- #endif
- #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- static inline void pmdp_set_wrprotect(struct mm_struct *mm,
- unsigned long address, pmd_t *pmdp)
- {
- pmd_t old_pmd = *pmdp;
- set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
- }
- #else
- static inline void pmdp_set_wrprotect(struct mm_struct *mm,
- unsigned long address, pmd_t *pmdp)
- {
- BUILD_BUG();
- }
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #endif
- #ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
- #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
- static inline void pudp_set_wrprotect(struct mm_struct *mm,
- unsigned long address, pud_t *pudp)
- {
- pud_t old_pud = *pudp;
- set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
- }
- #else
- static inline void pudp_set_wrprotect(struct mm_struct *mm,
- unsigned long address, pud_t *pudp)
- {
- BUILD_BUG();
- }
- #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
- #endif
- #ifndef pmdp_collapse_flush
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp);
- #else
- static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
- unsigned long address,
- pmd_t *pmdp)
- {
- BUILD_BUG();
- return *pmdp;
- }
- #define pmdp_collapse_flush pmdp_collapse_flush
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #endif
- #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
- extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
- pgtable_t pgtable);
- #endif
- #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
- extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
- #endif
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- /*
- * This is an implementation of pmdp_establish() that is only suitable for an
- * architecture that doesn't have hardware dirty/accessed bits. In this case we
- * can't race with CPU which sets these bits and non-atomic approach is fine.
- */
- static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp, pmd_t pmd)
- {
- pmd_t old_pmd = *pmdp;
- set_pmd_at(vma->vm_mm, address, pmdp, pmd);
- return old_pmd;
- }
- #endif
- #ifndef __HAVE_ARCH_PMDP_INVALIDATE
- extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp);
- #endif
- #ifndef __HAVE_ARCH_PMDP_INVALIDATE_AD
- /*
- * pmdp_invalidate_ad() invalidates the PMD while changing a transparent
- * hugepage mapping in the page tables. This function is similar to
- * pmdp_invalidate(), but should only be used if the access and dirty bits would
- * not be cleared by the software in the new PMD value. The function ensures
- * that hardware changes of the access and dirty bits updates would not be lost.
- *
- * Doing so can allow in certain architectures to avoid a TLB flush in most
- * cases. Yet, another TLB flush might be necessary later if the PMD update
- * itself requires such flush (e.g., if protection was set to be stricter). Yet,
- * even when a TLB flush is needed because of the update, the caller may be able
- * to batch these TLB flushing operations, so fewer TLB flush operations are
- * needed.
- */
- extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp);
- #endif
- #ifndef __HAVE_ARCH_PTE_SAME
- static inline int pte_same(pte_t pte_a, pte_t pte_b)
- {
- return pte_val(pte_a) == pte_val(pte_b);
- }
- #endif
- #ifndef __HAVE_ARCH_PTE_UNUSED
- /*
- * Some architectures provide facilities to virtualization guests
- * so that they can flag allocated pages as unused. This allows the
- * host to transparently reclaim unused pages. This function returns
- * whether the pte's page is unused.
- */
- static inline int pte_unused(pte_t pte)
- {
- return 0;
- }
- #endif
- #ifndef pte_access_permitted
- #define pte_access_permitted(pte, write) \
- (pte_present(pte) && (!(write) || pte_write(pte)))
- #endif
- #ifndef pmd_access_permitted
- #define pmd_access_permitted(pmd, write) \
- (pmd_present(pmd) && (!(write) || pmd_write(pmd)))
- #endif
- #ifndef pud_access_permitted
- #define pud_access_permitted(pud, write) \
- (pud_present(pud) && (!(write) || pud_write(pud)))
- #endif
- #ifndef p4d_access_permitted
- #define p4d_access_permitted(p4d, write) \
- (p4d_present(p4d) && (!(write) || p4d_write(p4d)))
- #endif
- #ifndef pgd_access_permitted
- #define pgd_access_permitted(pgd, write) \
- (pgd_present(pgd) && (!(write) || pgd_write(pgd)))
- #endif
- #ifndef __HAVE_ARCH_PMD_SAME
- static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
- {
- return pmd_val(pmd_a) == pmd_val(pmd_b);
- }
- static inline int pud_same(pud_t pud_a, pud_t pud_b)
- {
- return pud_val(pud_a) == pud_val(pud_b);
- }
- #endif
- #ifndef __HAVE_ARCH_P4D_SAME
- static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
- {
- return p4d_val(p4d_a) == p4d_val(p4d_b);
- }
- #endif
- #ifndef __HAVE_ARCH_PGD_SAME
- static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b)
- {
- return pgd_val(pgd_a) == pgd_val(pgd_b);
- }
- #endif
- /*
- * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
- * TLB flush will be required as a result of the "set". For example, use
- * in scenarios where it is known ahead of time that the routine is
- * setting non-present entries, or re-setting an existing entry to the
- * same value. Otherwise, use the typical "set" helpers and flush the
- * TLB.
- */
- #define set_pte_safe(ptep, pte) \
- ({ \
- WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
- set_pte(ptep, pte); \
- })
- #define set_pmd_safe(pmdp, pmd) \
- ({ \
- WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
- set_pmd(pmdp, pmd); \
- })
- #define set_pud_safe(pudp, pud) \
- ({ \
- WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
- set_pud(pudp, pud); \
- })
- #define set_p4d_safe(p4dp, p4d) \
- ({ \
- WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
- set_p4d(p4dp, p4d); \
- })
- #define set_pgd_safe(pgdp, pgd) \
- ({ \
- WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
- set_pgd(pgdp, pgd); \
- })
- #ifndef __HAVE_ARCH_DO_SWAP_PAGE
- /*
- * Some architectures support metadata associated with a page. When a
- * page is being swapped out, this metadata must be saved so it can be
- * restored when the page is swapped back in. SPARC M7 and newer
- * processors support an ADI (Application Data Integrity) tag for the
- * page as metadata for the page. arch_do_swap_page() can restore this
- * metadata when a page is swapped back in.
- */
- static inline void arch_do_swap_page(struct mm_struct *mm,
- struct vm_area_struct *vma,
- unsigned long addr,
- pte_t pte, pte_t oldpte)
- {
- }
- #endif
- #ifndef __HAVE_ARCH_UNMAP_ONE
- /*
- * Some architectures support metadata associated with a page. When a
- * page is being swapped out, this metadata must be saved so it can be
- * restored when the page is swapped back in. SPARC M7 and newer
- * processors support an ADI (Application Data Integrity) tag for the
- * page as metadata for the page. arch_unmap_one() can save this
- * metadata on a swap-out of a page.
- */
- static inline int arch_unmap_one(struct mm_struct *mm,
- struct vm_area_struct *vma,
- unsigned long addr,
- pte_t orig_pte)
- {
- return 0;
- }
- #endif
- /*
- * Allow architectures to preserve additional metadata associated with
- * swapped-out pages. The corresponding __HAVE_ARCH_SWAP_* macros and function
- * prototypes must be defined in the arch-specific asm/pgtable.h file.
- */
- #ifndef __HAVE_ARCH_PREPARE_TO_SWAP
- static inline int arch_prepare_to_swap(struct page *page)
- {
- return 0;
- }
- #endif
- #ifndef __HAVE_ARCH_SWAP_INVALIDATE
- static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
- {
- }
- static inline void arch_swap_invalidate_area(int type)
- {
- }
- #endif
- #ifndef __HAVE_ARCH_SWAP_RESTORE
- static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
- {
- }
- #endif
- #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
- #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
- #endif
- #ifndef __HAVE_ARCH_MOVE_PTE
- #define move_pte(pte, prot, old_addr, new_addr) (pte)
- #endif
- #ifndef pte_accessible
- # define pte_accessible(mm, pte) ((void)(pte), 1)
- #endif
- #ifndef flush_tlb_fix_spurious_fault
- #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
- #endif
- /*
- * When walking page tables, get the address of the next boundary,
- * or the end address of the range if that comes earlier. Although no
- * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
- */
- #define pgd_addr_end(addr, end) \
- ({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
- })
- #ifndef p4d_addr_end
- #define p4d_addr_end(addr, end) \
- ({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
- })
- #endif
- #ifndef pud_addr_end
- #define pud_addr_end(addr, end) \
- ({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
- })
- #endif
- #ifndef pmd_addr_end
- #define pmd_addr_end(addr, end) \
- ({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
- })
- #endif
- /*
- * When walking page tables, we usually want to skip any p?d_none entries;
- * and any p?d_bad entries - reporting the error before resetting to none.
- * Do the tests inline, but report and clear the bad entry in mm/memory.c.
- */
- void pgd_clear_bad(pgd_t *);
- #ifndef __PAGETABLE_P4D_FOLDED
- void p4d_clear_bad(p4d_t *);
- #else
- #define p4d_clear_bad(p4d) do { } while (0)
- #endif
- #ifndef __PAGETABLE_PUD_FOLDED
- void pud_clear_bad(pud_t *);
- #else
- #define pud_clear_bad(p4d) do { } while (0)
- #endif
- void pmd_clear_bad(pmd_t *);
- static inline int pgd_none_or_clear_bad(pgd_t *pgd)
- {
- if (pgd_none(*pgd))
- return 1;
- if (unlikely(pgd_bad(*pgd))) {
- pgd_clear_bad(pgd);
- return 1;
- }
- return 0;
- }
- static inline int p4d_none_or_clear_bad(p4d_t *p4d)
- {
- if (p4d_none(*p4d))
- return 1;
- if (unlikely(p4d_bad(*p4d))) {
- p4d_clear_bad(p4d);
- return 1;
- }
- return 0;
- }
- static inline int pud_none_or_clear_bad(pud_t *pud)
- {
- if (pud_none(*pud))
- return 1;
- if (unlikely(pud_bad(*pud))) {
- pud_clear_bad(pud);
- return 1;
- }
- return 0;
- }
- static inline int pmd_none_or_clear_bad(pmd_t *pmd)
- {
- if (pmd_none(*pmd))
- return 1;
- if (unlikely(pmd_bad(*pmd))) {
- pmd_clear_bad(pmd);
- return 1;
- }
- return 0;
- }
- static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma,
- unsigned long addr,
- pte_t *ptep)
- {
- /*
- * Get the current pte state, but zero it out to make it
- * non-present, preventing the hardware from asynchronously
- * updating it.
- */
- return ptep_get_and_clear(vma->vm_mm, addr, ptep);
- }
- static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
- unsigned long addr,
- pte_t *ptep, pte_t pte)
- {
- /*
- * The pte is non-present, so there's no hardware state to
- * preserve.
- */
- set_pte_at(vma->vm_mm, addr, ptep, pte);
- }
- #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
- /*
- * Start a pte protection read-modify-write transaction, which
- * protects against asynchronous hardware modifications to the pte.
- * The intention is not to prevent the hardware from making pte
- * updates, but to prevent any updates it may make from being lost.
- *
- * This does not protect against other software modifications of the
- * pte; the appropriate pte lock must be held over the transaction.
- *
- * Note that this interface is intended to be batchable, meaning that
- * ptep_modify_prot_commit may not actually update the pte, but merely
- * queue the update to be done at some later time. The update must be
- * actually committed before the pte lock is released, however.
- */
- static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
- unsigned long addr,
- pte_t *ptep)
- {
- return __ptep_modify_prot_start(vma, addr, ptep);
- }
- /*
- * Commit an update to a pte, leaving any hardware-controlled bits in
- * the PTE unmodified.
- */
- static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
- unsigned long addr,
- pte_t *ptep, pte_t old_pte, pte_t pte)
- {
- __ptep_modify_prot_commit(vma, addr, ptep, pte);
- }
- #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
- #endif /* CONFIG_MMU */
- /*
- * No-op macros that just return the current protection value. Defined here
- * because these macros can be used even if CONFIG_MMU is not defined.
- */
- #ifndef pgprot_nx
- #define pgprot_nx(prot) (prot)
- #endif
- #ifndef pgprot_noncached
- #define pgprot_noncached(prot) (prot)
- #endif
- #ifndef pgprot_writecombine
- #define pgprot_writecombine pgprot_noncached
- #endif
- #ifndef pgprot_writethrough
- #define pgprot_writethrough pgprot_noncached
- #endif
- #ifndef pgprot_device
- #define pgprot_device pgprot_noncached
- #endif
- #ifndef pgprot_mhp
- #define pgprot_mhp(prot) (prot)
- #endif
- #ifdef CONFIG_MMU
- #ifndef pgprot_modify
- #define pgprot_modify pgprot_modify
- static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
- {
- if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
- newprot = pgprot_noncached(newprot);
- if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
- newprot = pgprot_writecombine(newprot);
- if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
- newprot = pgprot_device(newprot);
- return newprot;
- }
- #endif
- #endif /* CONFIG_MMU */
- #ifndef pgprot_encrypted
- #define pgprot_encrypted(prot) (prot)
- #endif
- #ifndef pgprot_decrypted
- #define pgprot_decrypted(prot) (prot)
- #endif
- /*
- * A facility to provide lazy MMU batching. This allows PTE updates and
- * page invalidations to be delayed until a call to leave lazy MMU mode
- * is issued. Some architectures may benefit from doing this, and it is
- * beneficial for both shadow and direct mode hypervisors, which may batch
- * the PTE updates which happen during this window. Note that using this
- * interface requires that read hazards be removed from the code. A read
- * hazard could result in the direct mode hypervisor case, since the actual
- * write to the page tables may not yet have taken place, so reads though
- * a raw PTE pointer after it has been modified are not guaranteed to be
- * up to date. This mode can only be entered and left under the protection of
- * the page table locks for all page tables which may be modified. In the UP
- * case, this is required so that preemption is disabled, and in the SMP case,
- * it must synchronize the delayed page table writes properly on other CPUs.
- */
- #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
- #define arch_enter_lazy_mmu_mode() do {} while (0)
- #define arch_leave_lazy_mmu_mode() do {} while (0)
- #define arch_flush_lazy_mmu_mode() do {} while (0)
- #endif
- /*
- * A facility to provide batching of the reload of page tables and
- * other process state with the actual context switch code for
- * paravirtualized guests. By convention, only one of the batched
- * update (lazy) modes (CPU, MMU) should be active at any given time,
- * entry should never be nested, and entry and exits should always be
- * paired. This is for sanity of maintaining and reasoning about the
- * kernel code. In this case, the exit (end of the context switch) is
- * in architecture-specific code, and so doesn't need a generic
- * definition.
- */
- #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
- #define arch_start_context_switch(prev) do {} while (0)
- #endif
- /*
- * When replacing an anonymous page by a real (!non) swap entry, we clear
- * PG_anon_exclusive from the page and instead remember whether the flag was
- * set in the swp pte. During fork(), we have to mark the entry as !exclusive
- * (possibly shared). On swapin, we use that information to restore
- * PG_anon_exclusive, which is very helpful in cases where we might have
- * additional (e.g., FOLL_GET) references on a page and wouldn't be able to
- * detect exclusivity.
- *
- * These functions don't apply to non-swap entries (e.g., migration, hwpoison,
- * ...).
- */
- #ifndef __HAVE_ARCH_PTE_SWP_EXCLUSIVE
- static inline pte_t pte_swp_mkexclusive(pte_t pte)
- {
- return pte;
- }
- static inline int pte_swp_exclusive(pte_t pte)
- {
- return false;
- }
- static inline pte_t pte_swp_clear_exclusive(pte_t pte)
- {
- return pte;
- }
- #endif
- #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
- #ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
- static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- static inline int pmd_swp_soft_dirty(pmd_t pmd)
- {
- return 0;
- }
- static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- #endif
- #else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
- static inline int pte_soft_dirty(pte_t pte)
- {
- return 0;
- }
- static inline int pmd_soft_dirty(pmd_t pmd)
- {
- return 0;
- }
- static inline pte_t pte_mksoft_dirty(pte_t pte)
- {
- return pte;
- }
- static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- static inline pte_t pte_clear_soft_dirty(pte_t pte)
- {
- return pte;
- }
- static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
- {
- return pte;
- }
- static inline int pte_swp_soft_dirty(pte_t pte)
- {
- return 0;
- }
- static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
- {
- return pte;
- }
- static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- static inline int pmd_swp_soft_dirty(pmd_t pmd)
- {
- return 0;
- }
- static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
- {
- return pmd;
- }
- #endif
- #ifndef __HAVE_PFNMAP_TRACKING
- /*
- * Interfaces that can be used by architecture code to keep track of
- * memory type of pfn mappings specified by the remap_pfn_range,
- * vmf_insert_pfn.
- */
- /*
- * track_pfn_remap is called when a _new_ pfn mapping is being established
- * by remap_pfn_range() for physical range indicated by pfn and size.
- */
- static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
- unsigned long pfn, unsigned long addr,
- unsigned long size)
- {
- return 0;
- }
- /*
- * track_pfn_insert is called when a _new_ single pfn is established
- * by vmf_insert_pfn().
- */
- static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
- pfn_t pfn)
- {
- }
- /*
- * track_pfn_copy is called when vma that is covering the pfnmap gets
- * copied through copy_page_range().
- */
- static inline int track_pfn_copy(struct vm_area_struct *vma)
- {
- return 0;
- }
- /*
- * untrack_pfn is called while unmapping a pfnmap for a region.
- * untrack can be called for a specific region indicated by pfn and size or
- * can be for the entire vma (in which case pfn, size are zero).
- */
- static inline void untrack_pfn(struct vm_area_struct *vma,
- unsigned long pfn, unsigned long size,
- bool mm_wr_locked)
- {
- }
- /*
- * untrack_pfn_moved is called while mremapping a pfnmap for a new region.
- */
- static inline void untrack_pfn_moved(struct vm_area_struct *vma)
- {
- }
- #else
- extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
- unsigned long pfn, unsigned long addr,
- unsigned long size);
- extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
- pfn_t pfn);
- extern int track_pfn_copy(struct vm_area_struct *vma);
- extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
- unsigned long size, bool mm_wr_locked);
- extern void untrack_pfn_moved(struct vm_area_struct *vma);
- #endif
- #ifdef CONFIG_MMU
- #ifdef __HAVE_COLOR_ZERO_PAGE
- static inline int is_zero_pfn(unsigned long pfn)
- {
- extern unsigned long zero_pfn;
- unsigned long offset_from_zero_pfn = pfn - zero_pfn;
- return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
- }
- #define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
- #else
- static inline int is_zero_pfn(unsigned long pfn)
- {
- extern unsigned long zero_pfn;
- return pfn == zero_pfn;
- }
- static inline unsigned long my_zero_pfn(unsigned long addr)
- {
- extern unsigned long zero_pfn;
- return zero_pfn;
- }
- #endif
- #else
- static inline int is_zero_pfn(unsigned long pfn)
- {
- return 0;
- }
- static inline unsigned long my_zero_pfn(unsigned long addr)
- {
- return 0;
- }
- #endif /* CONFIG_MMU */
- #ifdef CONFIG_MMU
- #ifndef CONFIG_TRANSPARENT_HUGEPAGE
- static inline int pmd_trans_huge(pmd_t pmd)
- {
- return 0;
- }
- #ifndef pmd_write
- static inline int pmd_write(pmd_t pmd)
- {
- BUG();
- return 0;
- }
- #endif /* pmd_write */
- #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
- #ifndef pud_write
- static inline int pud_write(pud_t pud)
- {
- BUG();
- return 0;
- }
- #endif /* pud_write */
- #if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
- static inline int pmd_devmap(pmd_t pmd)
- {
- return 0;
- }
- static inline int pud_devmap(pud_t pud)
- {
- return 0;
- }
- static inline int pgd_devmap(pgd_t pgd)
- {
- return 0;
- }
- #endif
- #if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
- !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
- static inline int pud_trans_huge(pud_t pud)
- {
- return 0;
- }
- #endif
- /* See pmd_none_or_trans_huge_or_clear_bad for discussion. */
- static inline int pud_none_or_trans_huge_or_dev_or_clear_bad(pud_t *pud)
- {
- pud_t pudval = READ_ONCE(*pud);
- if (pud_none(pudval) || pud_trans_huge(pudval) || pud_devmap(pudval))
- return 1;
- if (unlikely(pud_bad(pudval))) {
- pud_clear_bad(pud);
- return 1;
- }
- return 0;
- }
- /* See pmd_trans_unstable for discussion. */
- static inline int pud_trans_unstable(pud_t *pud)
- {
- #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
- defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
- return pud_none_or_trans_huge_or_dev_or_clear_bad(pud);
- #else
- return 0;
- #endif
- }
- #ifndef pmd_read_atomic
- static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
- {
- /*
- * Depend on compiler for an atomic pmd read. NOTE: this is
- * only going to work, if the pmdval_t isn't larger than
- * an unsigned long.
- */
- return *pmdp;
- }
- #endif
- #ifndef arch_needs_pgtable_deposit
- #define arch_needs_pgtable_deposit() (false)
- #endif
- /*
- * This function is meant to be used by sites walking pagetables with
- * the mmap_lock held in read mode to protect against MADV_DONTNEED and
- * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
- * into a null pmd and the transhuge page fault can convert a null pmd
- * into an hugepmd or into a regular pmd (if the hugepage allocation
- * fails). While holding the mmap_lock in read mode the pmd becomes
- * stable and stops changing under us only if it's not null and not a
- * transhuge pmd. When those races occurs and this function makes a
- * difference vs the standard pmd_none_or_clear_bad, the result is
- * undefined so behaving like if the pmd was none is safe (because it
- * can return none anyway). The compiler level barrier() is critically
- * important to compute the two checks atomically on the same pmdval.
- *
- * For 32bit kernels with a 64bit large pmd_t this automatically takes
- * care of reading the pmd atomically to avoid SMP race conditions
- * against pmd_populate() when the mmap_lock is hold for reading by the
- * caller (a special atomic read not done by "gcc" as in the generic
- * version above, is also needed when THP is disabled because the page
- * fault can populate the pmd from under us).
- */
- static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
- {
- pmd_t pmdval = pmd_read_atomic(pmd);
- /*
- * The barrier will stabilize the pmdval in a register or on
- * the stack so that it will stop changing under the code.
- *
- * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
- * pmd_read_atomic is allowed to return a not atomic pmdval
- * (for example pointing to an hugepage that has never been
- * mapped in the pmd). The below checks will only care about
- * the low part of the pmd with 32bit PAE x86 anyway, with the
- * exception of pmd_none(). So the important thing is that if
- * the low part of the pmd is found null, the high part will
- * be also null or the pmd_none() check below would be
- * confused.
- */
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- barrier();
- #endif
- /*
- * !pmd_present() checks for pmd migration entries
- *
- * The complete check uses is_pmd_migration_entry() in linux/swapops.h
- * But using that requires moving current function and pmd_trans_unstable()
- * to linux/swapops.h to resolve dependency, which is too much code move.
- *
- * !pmd_present() is equivalent to is_pmd_migration_entry() currently,
- * because !pmd_present() pages can only be under migration not swapped
- * out.
- *
- * pmd_none() is preserved for future condition checks on pmd migration
- * entries and not confusing with this function name, although it is
- * redundant with !pmd_present().
- */
- if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
- (IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
- return 1;
- if (unlikely(pmd_bad(pmdval))) {
- pmd_clear_bad(pmd);
- return 1;
- }
- return 0;
- }
- /*
- * This is a noop if Transparent Hugepage Support is not built into
- * the kernel. Otherwise it is equivalent to
- * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
- * places that already verified the pmd is not none and they want to
- * walk ptes while holding the mmap sem in read mode (write mode don't
- * need this). If THP is not enabled, the pmd can't go away under the
- * code even if MADV_DONTNEED runs, but if THP is enabled we need to
- * run a pmd_trans_unstable before walking the ptes after
- * split_huge_pmd returns (because it may have run when the pmd become
- * null, but then a page fault can map in a THP and not a regular page).
- */
- static inline int pmd_trans_unstable(pmd_t *pmd)
- {
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- return pmd_none_or_trans_huge_or_clear_bad(pmd);
- #else
- return 0;
- #endif
- }
- /*
- * the ordering of these checks is important for pmds with _page_devmap set.
- * if we check pmd_trans_unstable() first we will trip the bad_pmd() check
- * inside of pmd_none_or_trans_huge_or_clear_bad(). this will end up correctly
- * returning 1 but not before it spams dmesg with the pmd_clear_bad() output.
- */
- static inline int pmd_devmap_trans_unstable(pmd_t *pmd)
- {
- return pmd_devmap(*pmd) || pmd_trans_unstable(pmd);
- }
- #ifndef CONFIG_NUMA_BALANCING
- /*
- * Technically a PTE can be PROTNONE even when not doing NUMA balancing but
- * the only case the kernel cares is for NUMA balancing and is only ever set
- * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
- * _PAGE_PROTNONE so by default, implement the helper as "always no". It
- * is the responsibility of the caller to distinguish between PROT_NONE
- * protections and NUMA hinting fault protections.
- */
- static inline int pte_protnone(pte_t pte)
- {
- return 0;
- }
- static inline int pmd_protnone(pmd_t pmd)
- {
- return 0;
- }
- #endif /* CONFIG_NUMA_BALANCING */
- #endif /* CONFIG_MMU */
- #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
- #ifndef __PAGETABLE_P4D_FOLDED
- int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
- void p4d_clear_huge(p4d_t *p4d);
- #else
- static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
- {
- return 0;
- }
- static inline void p4d_clear_huge(p4d_t *p4d) { }
- #endif /* !__PAGETABLE_P4D_FOLDED */
- int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
- int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
- int pud_clear_huge(pud_t *pud);
- int pmd_clear_huge(pmd_t *pmd);
- int p4d_free_pud_page(p4d_t *p4d, unsigned long addr);
- int pud_free_pmd_page(pud_t *pud, unsigned long addr);
- int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
- #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
- static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
- {
- return 0;
- }
- static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
- {
- return 0;
- }
- static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
- {
- return 0;
- }
- static inline void p4d_clear_huge(p4d_t *p4d) { }
- static inline int pud_clear_huge(pud_t *pud)
- {
- return 0;
- }
- static inline int pmd_clear_huge(pmd_t *pmd)
- {
- return 0;
- }
- static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
- {
- return 0;
- }
- static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
- {
- return 0;
- }
- static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
- {
- return 0;
- }
- #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
- #ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
- #ifdef CONFIG_TRANSPARENT_HUGEPAGE
- /*
- * ARCHes with special requirements for evicting THP backing TLB entries can
- * implement this. Otherwise also, it can help optimize normal TLB flush in
- * THP regime. Stock flush_tlb_range() typically has optimization to nuke the
- * entire TLB if flush span is greater than a threshold, which will
- * likely be true for a single huge page. Thus a single THP flush will
- * invalidate the entire TLB which is not desirable.
- * e.g. see arch/arc: flush_pmd_tlb_range
- */
- #define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
- #define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
- #else
- #define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG()
- #define flush_pud_tlb_range(vma, addr, end) BUILD_BUG()
- #endif
- #endif
- struct file;
- int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
- unsigned long size, pgprot_t *vma_prot);
- #ifndef CONFIG_X86_ESPFIX64
- static inline void init_espfix_bsp(void) { }
- #endif
- extern void __init pgtable_cache_init(void);
- #ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
- static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
- {
- return true;
- }
- static inline bool arch_has_pfn_modify_check(void)
- {
- return false;
- }
- #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
- /*
- * Architecture PAGE_KERNEL_* fallbacks
- *
- * Some architectures don't define certain PAGE_KERNEL_* flags. This is either
- * because they really don't support them, or the port needs to be updated to
- * reflect the required functionality. Below are a set of relatively safe
- * fallbacks, as best effort, which we can count on in lieu of the architectures
- * not defining them on their own yet.
- */
- #ifndef PAGE_KERNEL_RO
- # define PAGE_KERNEL_RO PAGE_KERNEL
- #endif
- #ifndef PAGE_KERNEL_EXEC
- # define PAGE_KERNEL_EXEC PAGE_KERNEL
- #endif
- /*
- * Page Table Modification bits for pgtbl_mod_mask.
- *
- * These are used by the p?d_alloc_track*() set of functions an in the generic
- * vmalloc/ioremap code to track at which page-table levels entries have been
- * modified. Based on that the code can better decide when vmalloc and ioremap
- * mapping changes need to be synchronized to other page-tables in the system.
- */
- #define __PGTBL_PGD_MODIFIED 0
- #define __PGTBL_P4D_MODIFIED 1
- #define __PGTBL_PUD_MODIFIED 2
- #define __PGTBL_PMD_MODIFIED 3
- #define __PGTBL_PTE_MODIFIED 4
- #define PGTBL_PGD_MODIFIED BIT(__PGTBL_PGD_MODIFIED)
- #define PGTBL_P4D_MODIFIED BIT(__PGTBL_P4D_MODIFIED)
- #define PGTBL_PUD_MODIFIED BIT(__PGTBL_PUD_MODIFIED)
- #define PGTBL_PMD_MODIFIED BIT(__PGTBL_PMD_MODIFIED)
- #define PGTBL_PTE_MODIFIED BIT(__PGTBL_PTE_MODIFIED)
- /* Page-Table Modification Mask */
- typedef unsigned int pgtbl_mod_mask;
- #endif /* !__ASSEMBLY__ */
- #if !defined(MAX_POSSIBLE_PHYSMEM_BITS) && !defined(CONFIG_64BIT)
- #ifdef CONFIG_PHYS_ADDR_T_64BIT
- /*
- * ZSMALLOC needs to know the highest PFN on 32-bit architectures
- * with physical address space extension, but falls back to
- * BITS_PER_LONG otherwise.
- */
- #error Missing MAX_POSSIBLE_PHYSMEM_BITS definition
- #else
- #define MAX_POSSIBLE_PHYSMEM_BITS 32
- #endif
- #endif
- #ifndef has_transparent_hugepage
- #define has_transparent_hugepage() IS_BUILTIN(CONFIG_TRANSPARENT_HUGEPAGE)
- #endif
- /*
- * On some architectures it depends on the mm if the p4d/pud or pmd
- * layer of the page table hierarchy is folded or not.
- */
- #ifndef mm_p4d_folded
- #define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED)
- #endif
- #ifndef mm_pud_folded
- #define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED)
- #endif
- #ifndef mm_pmd_folded
- #define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
- #endif
- #ifndef p4d_offset_lockless
- #define p4d_offset_lockless(pgdp, pgd, address) p4d_offset(&(pgd), address)
- #endif
- #ifndef pud_offset_lockless
- #define pud_offset_lockless(p4dp, p4d, address) pud_offset(&(p4d), address)
- #endif
- #ifndef pmd_offset_lockless
- #define pmd_offset_lockless(pudp, pud, address) pmd_offset(&(pud), address)
- #endif
- /*
- * p?d_leaf() - true if this entry is a final mapping to a physical address.
- * This differs from p?d_huge() by the fact that they are always available (if
- * the architecture supports large pages at the appropriate level) even
- * if CONFIG_HUGETLB_PAGE is not defined.
- * Only meaningful when called on a valid entry.
- */
- #ifndef pgd_leaf
- #define pgd_leaf(x) 0
- #endif
- #ifndef p4d_leaf
- #define p4d_leaf(x) 0
- #endif
- #ifndef pud_leaf
- #define pud_leaf(x) 0
- #endif
- #ifndef pmd_leaf
- #define pmd_leaf(x) 0
- #endif
- #ifndef pgd_leaf_size
- #define pgd_leaf_size(x) (1ULL << PGDIR_SHIFT)
- #endif
- #ifndef p4d_leaf_size
- #define p4d_leaf_size(x) P4D_SIZE
- #endif
- #ifndef pud_leaf_size
- #define pud_leaf_size(x) PUD_SIZE
- #endif
- #ifndef pmd_leaf_size
- #define pmd_leaf_size(x) PMD_SIZE
- #endif
- #ifndef pte_leaf_size
- #define pte_leaf_size(x) PAGE_SIZE
- #endif
- /*
- * Some architectures have MMUs that are configurable or selectable at boot
- * time. These lead to variable PTRS_PER_x. For statically allocated arrays it
- * helps to have a static maximum value.
- */
- #ifndef MAX_PTRS_PER_PTE
- #define MAX_PTRS_PER_PTE PTRS_PER_PTE
- #endif
- #ifndef MAX_PTRS_PER_PMD
- #define MAX_PTRS_PER_PMD PTRS_PER_PMD
- #endif
- #ifndef MAX_PTRS_PER_PUD
- #define MAX_PTRS_PER_PUD PTRS_PER_PUD
- #endif
- #ifndef MAX_PTRS_PER_P4D
- #define MAX_PTRS_PER_P4D PTRS_PER_P4D
- #endif
- /* description of effects of mapping type and prot in current implementation.
- * this is due to the limited x86 page protection hardware. The expected
- * behavior is in parens:
- *
- * map_type prot
- * PROT_NONE PROT_READ PROT_WRITE PROT_EXEC
- * MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes
- * w: (no) no w: (no) no w: (yes) yes w: (no) no
- * x: (no) no x: (no) yes x: (no) yes x: (yes) yes
- *
- * MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes
- * w: (no) no w: (no) no w: (copy) copy w: (no) no
- * x: (no) no x: (no) yes x: (no) yes x: (yes) yes
- *
- * On arm64, PROT_EXEC has the following behaviour for both MAP_SHARED and
- * MAP_PRIVATE (with Enhanced PAN supported):
- * r: (no) no
- * w: (no) no
- * x: (yes) yes
- */
- #define DECLARE_VM_GET_PAGE_PROT \
- pgprot_t vm_get_page_prot(unsigned long vm_flags) \
- { \
- return protection_map[vm_flags & \
- (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)]; \
- } \
- EXPORT_SYMBOL(vm_get_page_prot);
- #endif /* _LINUX_PGTABLE_H */
|