diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/gup.c | 7 | ||||
| -rw-r--r-- | mm/huge_memory.c | 249 | ||||
| -rw-r--r-- | mm/memory.c | 88 | ||||
| -rw-r--r-- | mm/pagewalk.c | 20 | ||||
| -rw-r--r-- | mm/pgtable-generic.c | 14 |
5 files changed, 370 insertions, 8 deletions
@@ -253,6 +253,13 @@ struct page *follow_page_mask(struct vm_area_struct *vma, return page; return no_page_table(vma, flags); } + if (pud_devmap(*pud)) { + ptl = pud_lock(mm, pud); + page = follow_devmap_pud(vma, address, pud, flags); + spin_unlock(ptl); + if (page) + return page; + } if (unlikely(pud_bad(*pud))) return no_page_table(vma, flags); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f9ecc2aeadfc..85742ac5b32e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -757,6 +757,60 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, } EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_WRITE)) + pud = pud_mkwrite(pud); + return pud; +} + +static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, + pud_t *pud, pfn_t pfn, pgprot_t prot, bool write) +{ + struct mm_struct *mm = vma->vm_mm; + pud_t entry; + spinlock_t *ptl; + + ptl = pud_lock(mm, pud); + entry = pud_mkhuge(pfn_t_pud(pfn, prot)); + if (pfn_t_devmap(pfn)) + entry = pud_mkdevmap(entry); + if (write) { + entry = pud_mkyoung(pud_mkdirty(entry)); + entry = maybe_pud_mkwrite(entry, vma); + } + set_pud_at(mm, addr, pud, entry); + update_mmu_cache_pud(vma, addr, pud); + spin_unlock(ptl); +} + +int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, + pud_t *pud, pfn_t pfn, bool write) +{ + pgprot_t pgprot = vma->vm_page_prot; + /* + * If we had pud_special, we could avoid all these restrictions, + * but we need to be consistent with PTEs and architectures that + * can't support a 'special' bit. + */ + BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); + BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == + (VM_PFNMAP|VM_MIXEDMAP)); + BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); + BUG_ON(!pfn_t_devmap(pfn)); + + if (addr < vma->vm_start || addr >= vma->vm_end) + return VM_FAULT_SIGBUS; + + track_pfn_insert(vma, &pgprot, pfn); + + insert_pfn_pud(vma, addr, pud, pfn, pgprot, write); + return VM_FAULT_NOPAGE; +} +EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ + static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd) { @@ -887,6 +941,123 @@ out: return ret; } +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void touch_pud(struct vm_area_struct *vma, unsigned long addr, + pud_t *pud) +{ + pud_t _pud; + + /* + * We should set the dirty bit only for FOLL_WRITE but for now + * the dirty bit in the pud is meaningless. And if the dirty + * bit will become meaningful and we'll only set it with + * FOLL_WRITE, an atomic set_bit will be required on the pud to + * set the young bit, instead of the current set_pud_at. + */ + _pud = pud_mkyoung(pud_mkdirty(*pud)); + if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK, + pud, _pud, 1)) + update_mmu_cache_pud(vma, addr, pud); +} + +struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, + pud_t *pud, int flags) +{ + unsigned long pfn = pud_pfn(*pud); + struct mm_struct *mm = vma->vm_mm; + struct dev_pagemap *pgmap; + struct page *page; + + assert_spin_locked(pud_lockptr(mm, pud)); + + if (flags & FOLL_WRITE && !pud_write(*pud)) + return NULL; + + if (pud_present(*pud) && pud_devmap(*pud)) + /* pass */; + else + return NULL; + + if (flags & FOLL_TOUCH) + touch_pud(vma, addr, pud); + + /* + * device mapped pages can only be returned if the + * caller will manage the page reference count. + */ + if (!(flags & FOLL_GET)) + return ERR_PTR(-EEXIST); + + pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT; + pgmap = get_dev_pagemap(pfn, NULL); + if (!pgmap) + return ERR_PTR(-EFAULT); + page = pfn_to_page(pfn); + get_page(page); + put_dev_pagemap(pgmap); + + return page; +} + +int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm, + pud_t *dst_pud, pud_t *src_pud, unsigned long addr, + struct vm_area_struct *vma) +{ + spinlock_t *dst_ptl, *src_ptl; + pud_t pud; + int ret; + + dst_ptl = pud_lock(dst_mm, dst_pud); + src_ptl = pud_lockptr(src_mm, src_pud); + spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); + + ret = -EAGAIN; + pud = *src_pud; + if (unlikely(!pud_trans_huge(pud) && !pud_devmap(pud))) + goto out_unlock; + + /* + * When page table lock is held, the huge zero pud should not be + * under splitting since we don't split the page itself, only pud to + * a page table. + */ + if (is_huge_zero_pud(pud)) { + /* No huge zero pud yet */ + } + + pudp_set_wrprotect(src_mm, addr, src_pud); + pud = pud_mkold(pud_wrprotect(pud)); + set_pud_at(dst_mm, addr, dst_pud, pud); + + ret = 0; +out_unlock: + spin_unlock(src_ptl); + spin_unlock(dst_ptl); + return ret; +} + +void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) +{ + pud_t entry; + unsigned long haddr; + bool write = vmf->flags & FAULT_FLAG_WRITE; + + vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud); + if (unlikely(!pud_same(*vmf->pud, orig_pud))) + goto unlock; + + entry = pud_mkyoung(orig_pud); + if (write) + entry = pud_mkdirty(entry); + haddr = vmf->address & HPAGE_PUD_MASK; + if (pudp_set_access_flags(vmf->vma, haddr, vmf->pud, entry, write)) + update_mmu_cache_pud(vmf->vma, vmf->address, vmf->pud); + +unlock: + spin_unlock(vmf->ptl); +} +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ + void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd) { pmd_t entry; @@ -1601,6 +1772,84 @@ spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) return NULL; } +/* + * Returns true if a given pud maps a thp, false otherwise. + * + * Note that if it returns true, this routine returns without unlocking page + * table lock. So callers must unlock it. + */ +spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma) +{ + spinlock_t *ptl; + + ptl = pud_lock(vma->vm_mm, pud); + if (likely(pud_trans_huge(*pud) || pud_devmap(*pud))) + return ptl; + spin_unlock(ptl); + return NULL; +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, + pud_t *pud, unsigned long addr) +{ + pud_t orig_pud; + spinlock_t *ptl; + + ptl = __pud_trans_huge_lock(pud, vma); + if (!ptl) + return 0; + /* + * For architectures like ppc64 we look at deposited pgtable + * when calling pudp_huge_get_and_clear. So do the + * pgtable_trans_huge_withdraw after finishing pudp related + * operations. + */ + orig_pud = pudp_huge_get_and_clear_full(tlb->mm, addr, pud, + tlb->fullmm); + tlb_remove_pud_tlb_entry(tlb, pud, addr); + if (vma_is_dax(vma)) { + spin_unlock(ptl); + /* No zero page support yet */ + } else { + /* No support for anonymous PUD pages yet */ + BUG(); + } + return 1; +} + +static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud, + unsigned long haddr) +{ + VM_BUG_ON(haddr & ~HPAGE_PUD_MASK); + VM_BUG_ON_VMA(vma->vm_start > haddr, vma); + VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma); + VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud)); + + count_vm_event(THP_SPLIT_PMD); + + pudp_huge_clear_flush_notify(vma, haddr, pud); +} + +void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud, + unsigned long address) +{ + spinlock_t *ptl; + struct mm_struct *mm = vma->vm_mm; + unsigned long haddr = address & HPAGE_PUD_MASK; + + mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PUD_SIZE); + ptl = pud_lock(mm, pud); + if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud))) + goto out; + __split_huge_pud_locked(vma, pud, haddr); + +out: + spin_unlock(ptl); + mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PUD_SIZE); +} +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ + static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd) { diff --git a/mm/memory.c b/mm/memory.c index e721e8eba570..41e2a2d4b2a6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1001,7 +1001,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src next = pmd_addr_end(addr, end); if (pmd_trans_huge(*src_pmd) || pmd_devmap(*src_pmd)) { int err; - VM_BUG_ON(next-addr != HPAGE_PMD_SIZE); + VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, vma); err = copy_huge_pmd(dst_mm, src_mm, dst_pmd, src_pmd, addr, vma); if (err == -ENOMEM) @@ -1032,6 +1032,18 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src src_pud = pud_offset(src_pgd, addr); do { next = pud_addr_end(addr, end); + if (pud_trans_huge(*src_pud) || pud_devmap(*src_pud)) { + int err; + + VM_BUG_ON_VMA(next-addr != HPAGE_PUD_SIZE, vma); + err = copy_huge_pud(dst_mm, src_mm, + dst_pud, src_pud, addr, vma); + if (err == -ENOMEM) + return -ENOMEM; + if (!err) + continue; + /* fall through */ + } if (pud_none_or_clear_bad(src_pud)) continue; if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud, @@ -1263,9 +1275,19 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, pud = pud_offset(pgd, addr); do { next = pud_addr_end(addr, end); + if (pud_trans_huge(*pud) || pud_devmap(*pud)) { + if (next - addr != HPAGE_PUD_SIZE) { + VM_BUG_ON_VMA(!rwsem_is_locked(&tlb->mm->mmap_sem), vma); + split_huge_pud(vma, pud, addr); + } else if (zap_huge_pud(tlb, vma, pud, addr)) + goto next; + /* fall through */ + } if (pud_none_or_clear_bad(pud)) continue; next = zap_pmd_range(tlb, vma, pud, addr, next, details); +next: + cond_resched(); } while (pud++, addr = next, addr != end); return addr; @@ -3490,6 +3512,30 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma) return vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE); } +static int create_huge_pud(struct vm_fault *vmf) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* No support for anonymous transparent PUD pages yet */ + if (vma_is_anonymous(vmf->vma)) + return VM_FAULT_FALLBACK; + if (vmf->vma->vm_ops->huge_fault) + return vmf->vma->vm_ops->huge_fault(vmf); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + return VM_FAULT_FALLBACK; +} + +static int wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* No support for anonymous transparent PUD pages yet */ + if (vma_is_anonymous(vmf->vma)) + return VM_FAULT_FALLBACK; + if (vmf->vma->vm_ops->huge_fault) + return vmf->vma->vm_ops->huge_fault(vmf); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + return VM_FAULT_FALLBACK; +} + /* * These routines also need to handle stuff like marking pages dirty * and/or accessed for architectures that don't do it in hardware (most @@ -3605,14 +3651,41 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address, }; struct mm_struct *mm = vma->vm_mm; pgd_t *pgd; - pud_t *pud; int ret; pgd = pgd_offset(mm, address); - pud = pud_alloc(mm, pgd, address); - if (!pud) + + vmf.pud = pud_alloc(mm, pgd, address); + if (!vmf.pud) return VM_FAULT_OOM; - vmf.pmd = pmd_alloc(mm, pud, address); + if (pud_none(*vmf.pud) && transparent_hugepage_enabled(vma)) { + vmf.flags |= FAULT_FLAG_SIZE_PUD; + ret = create_huge_pud(&vmf); + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + } else { + pud_t orig_pud = *vmf.pud; + + barrier(); + if (pud_trans_huge(orig_pud) || pud_devmap(orig_pud)) { + unsigned int dirty = flags & FAULT_FLAG_WRITE; + + vmf.flags |= FAULT_FLAG_SIZE_PUD; + + /* NUMA case for anonymous PUDs would go here */ + + if (dirty && !pud_write(orig_pud)) { + ret = wp_huge_pud(&vmf, orig_pud); + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + } else { + huge_pud_set_accessed(&vmf, orig_pud); + return 0; + } + } + } + + vmf.pmd = pmd_alloc(mm, vmf.pud, address); if (!vmf.pmd) return VM_FAULT_OOM; if (pmd_none(*vmf.pmd) && transparent_hugepage_enabled(vma)) { @@ -3743,13 +3816,14 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) */ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) { + spinlock_t *ptl; pmd_t *new = pmd_alloc_one(mm, address); if (!new) return -ENOMEM; smp_wmb(); /* See comment in __pte_alloc */ - spin_lock(&mm->page_table_lock); + ptl = pud_lock(mm, pud); #ifndef __ARCH_HAS_4LEVEL_HACK if (!pud_present(*pud)) { mm_inc_nr_pmds(mm); @@ -3763,7 +3837,7 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) } else /* Another has populated it */ pmd_free(mm, new); #endif /* __ARCH_HAS_4LEVEL_HACK */ - spin_unlock(&mm->page_table_lock); + spin_unlock(ptl); return 0; } #endif /* __PAGETABLE_PMD_FOLDED */ diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 207244489a68..03761577ae86 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -78,14 +78,32 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, pud = pud_offset(pgd, addr); do { + again: next = pud_addr_end(addr, end); - if (pud_none_or_clear_bad(pud)) { + if (pud_none(*pud) || !walk->vma) { if (walk->pte_hole) err = walk->pte_hole(addr, next, walk); if (err) break; continue; } + + if (walk->pud_entry) { + spinlock_t *ptl = pud_trans_huge_lock(pud, walk->vma); + + if (ptl) { + err = walk->pud_entry(pud, addr, next, walk); + spin_unlock(ptl); + if (err) + break; + continue; + } + } + + split_huge_pud(walk->vma, pud, addr); + if (pud_none(*pud)) + goto again; + if (walk->pmd_entry || walk->pte_entry) err = walk_pmd_range(pud, addr, next, walk); if (err) diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index 71c5f9109f2a..4ed5908c65b0 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -123,6 +123,20 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return pmd; } + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, + pud_t *pudp) +{ + pud_t pud; + + VM_BUG_ON(address & ~HPAGE_PUD_MASK); + VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp)); + pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp); + flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE); + return pud; +} +#endif #endif #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT |