/* * IA-32 Huge TLB Page Support for Kernel. * * Copyright (C) 2002, Rohit Seth */ #include #include #include #include #include #include #include #include #include #include #include #include #include pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte = NULL; pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); pmd = pmd_alloc(mm, pud, addr); if (!pmd) goto out; pte = (pte_t *) pmd; if (!pte_none(*pte) && !pte_huge(*pte)) hugetlb_clean_stale_pgtable(pte); out: return pte; } pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd = NULL; pgd = pgd_offset(mm, addr); pud = pud_offset(pgd, addr); pmd = pmd_offset(pud, addr); return (pte_t *) pmd; } /* * This function checks for proper alignment of input addr and len parameters. */ int is_aligned_hugepage_range(unsigned long addr, unsigned long len) { if (len & ~HPAGE_MASK) return -EINVAL; if (addr & ~HPAGE_MASK) return -EINVAL; return 0; } #if 0 /* This is just for testing */ struct page * follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) { unsigned long start = address; int length = 1; int nr; struct page *page; struct vm_area_struct *vma; vma = find_vma(mm, addr); if (!vma || !is_vm_hugetlb_page(vma)) return ERR_PTR(-EINVAL); pte = huge_pte_offset(mm, address); /* hugetlb should be locked, and hence, prefaulted */ WARN_ON(!pte || pte_none(*pte)); page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; WARN_ON(!PageCompound(page)); return page; } int pmd_huge(pmd_t pmd) { return 0; } struct page * follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { return NULL; } #else struct page * follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) { return ERR_PTR(-EINVAL); } int pmd_huge(pmd_t pmd) { return !!(pmd_val(pmd) & _PAGE_PSE); } struct page * follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { struct page *page; page = pte_page(*(pte_t *)pmd); if (page) page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); return page; } #endif void hugetlb_clean_stale_pgtable(pte_t *pte) { pmd_t *pmd = (pmd_t *) pte; struct page *page; page = pmd_page(*pmd); pmd_clear(pmd); dec_page_state(nr_page_table_pages); page_cache_release(page); } /* x86_64 also uses this file */ #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long start_addr; if (len > mm->cached_hole_size) { start_addr = mm->free_area_cache; } else { start_addr = TASK_UNMAPPED_BASE; mm->cached_hole_size = 0; } full_search: addr = ALIGN(start_addr, HPAGE_SIZE); for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { /* At this point: (!vma || addr < vma->vm_end). */ if (TASK_SIZE - len < addr) { /* * Start a new search - just in case we missed * some holes. */ if (start_addr != TASK_UNMAPPED_BASE) { start_addr = TASK_UNMAPPED_BASE; mm->cached_hole_size = 0; goto full_search; } return -ENOMEM; } if (!vma || addr + len <= vma->vm_start) { mm->free_area_cache = addr + len; return addr; } if (addr + mm->cached_hole_size < vma->vm_start) mm->cached_hole_size = vma->vm_start - addr; addr = ALIGN(vma->vm_end, HPAGE_SIZE); } } static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr0, unsigned long len, unsigned long pgoff, unsigned long flags) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev_vma; unsigned long base = mm->mmap_base, addr = addr0; unsigned long largest_hole = mm->cached_hole_size; int first_time = 1; /* don't allow allocations above current base */ if (mm->free_area_cache > base) mm->free_area_cache = base; if (len <= largest_hole) { largest_hole = 0; mm->free_area_cache = base; } try_again: /* make sure it can fit in the remaining address space */ if (mm->free_area_cache < len) goto fail; /* either no address requested or cant fit in requested address hole */ addr = (mm->free_area_cache - len) & HPAGE_MASK; do { /* * Lookup failure means no vma is above this address, * i.e. return with success: */ if (!(vma = find_vma_prev(mm, addr, &prev_vma))) return addr; /* * new region fits between prev_vma->vm_end and * vma->vm_start, use it: */ if (addr + len <= vma->vm_start && (!prev_vma || (addr >= prev_vma->vm_end))) { /* remember the address as a hint for next time */ mm->cached_hole_size = largest_hole; return (mm->free_area_cache = addr); } else { /* pull free_area_cache down to the first hole */ if (mm->free_area_cache == vma->vm_end) { mm->free_area_cache = vma->vm_start; mm->cached_hole_size = largest_hole; } } /* remember the largest hole we saw so far */ if (addr + largest_hole < vma->vm_start) largest_hole = vma->vm_start - addr; /* try just below the current vma->vm_start */ addr = (vma->vm_start - len) & HPAGE_MASK; } while (len <= vma->vm_start); fail: /* * if hint left us with no space for the requested * mapping then try again: */ if (first_time) { mm->free_area_cache = base; largest_hole = 0; first_time = 0; goto try_again; } /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario * can happen with large stack limits and large mmap() * allocations. */ mm->free_area_cache = TASK_UNMAPPED_BASE; mm->cached_hole_size = ~0UL; addr = hugetlb_get_unmapped_area_bottomup(file, addr0, len, pgoff, flags); /* * Restore the topdown base: */ mm->free_area_cache = base; mm->cached_hole_size = ~0UL; return addr; } unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; if (len & ~HPAGE_MASK) return -EINVAL; if (len > TASK_SIZE) return -ENOMEM; if (addr) { addr = ALIGN(addr, HPAGE_SIZE); vma = find_vma(mm, addr); if (TASK_SIZE - len >= addr && (!vma || addr + len <= vma->vm_start)) return addr; } if (mm->get_unmapped_area == arch_get_unmapped_area) return hugetlb_get_unmapped_area_bottomup(file, addr, len, pgoff, flags); else return hugetlb_get_unmapped_area_topdown(file, addr, len, pgoff, flags); } #endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/