diff options
Diffstat (limited to 'arch/i386/mm')
-rw-r--r-- | arch/i386/mm/highmem.c | 26 | ||||
-rw-r--r-- | arch/i386/mm/hugetlbpage.c | 112 | ||||
-rw-r--r-- | arch/i386/mm/init.c | 4 | ||||
-rw-r--r-- | arch/i386/mm/pgtable.c | 6 |
4 files changed, 127 insertions, 21 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c index f9f647cdbc7..e0fa6cb655a 100644 --- a/arch/i386/mm/highmem.c +++ b/arch/i386/mm/highmem.c @@ -32,7 +32,7 @@ void *kmap_atomic(struct page *page, enum km_type type) unsigned long vaddr; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - inc_preempt_count(); + pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -50,26 +50,22 @@ void kunmap_atomic(void *kvaddr, enum km_type type) unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); -#ifdef CONFIG_DEBUG_HIGHMEM - if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) { - dec_preempt_count(); - preempt_check_resched(); - return; - } - - if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx)) - BUG(); -#endif /* * Force other mappings to Oops if they'll try to access this pte * without first remap it. Keeping stale mappings around is a bad idea * also, in case the page changes cacheability attributes or becomes * a protected page in a hypervisor. */ - kpte_clear_flush(kmap_pte-idx, vaddr); + if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) + kpte_clear_flush(kmap_pte-idx, vaddr); + else { +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(vaddr < PAGE_OFFSET); + BUG_ON(vaddr >= (unsigned long)high_memory); +#endif + } - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } /* This is the same as kmap_atomic() but can map memory that doesn't @@ -80,7 +76,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) enum fixed_addresses idx; unsigned long vaddr; - inc_preempt_count(); + pagefault_disable(); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); diff --git a/arch/i386/mm/hugetlbpage.c b/arch/i386/mm/hugetlbpage.c index 1719a8141f8..34728e4afe4 100644 --- a/arch/i386/mm/hugetlbpage.c +++ b/arch/i386/mm/hugetlbpage.c @@ -17,6 +17,113 @@ #include <asm/tlb.h> #include <asm/tlbflush.h> +static unsigned long page_table_shareable(struct vm_area_struct *svma, + struct vm_area_struct *vma, + unsigned long addr, pgoff_t idx) +{ + unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + + svma->vm_start; + unsigned long sbase = saddr & PUD_MASK; + unsigned long s_end = sbase + PUD_SIZE; + + /* + * match the virtual addresses, permission and the alignment of the + * page table page. + */ + if (pmd_index(addr) != pmd_index(saddr) || + vma->vm_flags != svma->vm_flags || + sbase < svma->vm_start || svma->vm_end < s_end) + return 0; + + return saddr; +} + +static int vma_shareable(struct vm_area_struct *vma, unsigned long addr) +{ + unsigned long base = addr & PUD_MASK; + unsigned long end = base + PUD_SIZE; + + /* + * check on proper vm_flags and page table alignment + */ + if (vma->vm_flags & VM_MAYSHARE && + vma->vm_start <= base && end <= vma->vm_end) + return 1; + return 0; +} + +/* + * search for a shareable pmd page for hugetlb. + */ +static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) +{ + struct vm_area_struct *vma = find_vma(mm, addr); + struct address_space *mapping = vma->vm_file->f_mapping; + pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + + vma->vm_pgoff; + struct prio_tree_iter iter; + struct vm_area_struct *svma; + unsigned long saddr; + pte_t *spte = NULL; + + if (!vma_shareable(vma, addr)) + return; + + spin_lock(&mapping->i_mmap_lock); + vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) { + if (svma == vma) + continue; + + saddr = page_table_shareable(svma, vma, addr, idx); + if (saddr) { + spte = huge_pte_offset(svma->vm_mm, saddr); + if (spte) { + get_page(virt_to_page(spte)); + break; + } + } + } + + if (!spte) + goto out; + + spin_lock(&mm->page_table_lock); + if (pud_none(*pud)) + pud_populate(mm, pud, (unsigned long) spte & PAGE_MASK); + else + put_page(virt_to_page(spte)); + spin_unlock(&mm->page_table_lock); +out: + spin_unlock(&mapping->i_mmap_lock); +} + +/* + * unmap huge page backed by shared pte. + * + * Hugetlb pte page is ref counted at the time of mapping. If pte is shared + * indicated by page_count > 1, unmap is achieved by clearing pud and + * decrementing the ref count. If count == 1, the pte page is not shared. + * + * called with vma->vm_mm->page_table_lock held. + * + * returns: 1 successfully unmapped a shared pte page + * 0 the underlying pte page is not shared, or it is the last user + */ +int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) +{ + pgd_t *pgd = pgd_offset(mm, *addr); + pud_t *pud = pud_offset(pgd, *addr); + + BUG_ON(page_count(virt_to_page(ptep)) == 0); + if (page_count(virt_to_page(ptep)) == 1) + return 0; + + pud_clear(pud); + put_page(virt_to_page(ptep)); + *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; + return 1; +} + pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; @@ -25,8 +132,11 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr) pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); - if (pud) + if (pud) { + if (pud_none(*pud)) + huge_pmd_share(mm, addr, pud); pte = (pte_t *) pmd_alloc(mm, pud, addr); + } BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte)); return pte; diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index f4dd048187f..84697dfc734 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -697,8 +697,8 @@ int remove_memory(u64 start, u64 size) #endif #endif -kmem_cache_t *pgd_cache; -kmem_cache_t *pmd_cache; +struct kmem_cache *pgd_cache; +struct kmem_cache *pmd_cache; void __init pgtable_cache_init(void) { diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c index 65b5c095903..f349eaf450b 100644 --- a/arch/i386/mm/pgtable.c +++ b/arch/i386/mm/pgtable.c @@ -196,7 +196,7 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) return pte; } -void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags) +void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags) { memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t)); } @@ -236,7 +236,7 @@ static inline void pgd_list_del(pgd_t *pgd) set_page_private(next, (unsigned long)pprev); } -void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused) +void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused) { unsigned long flags; @@ -256,7 +256,7 @@ void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused) } /* never called when PTRS_PER_PMD > 1 */ -void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused) +void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused) { unsigned long flags; /* can be called from interrupt context */ |