From: Hugh Dickins Convert remap_pfn_range pagetable walkers to loops using p?d_addr_end. Remove the redundant flush_tlb_range from afterwards: as its comment noted, there's already a BUG_ON(!pte_none). Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton --- 25-akpm/mm/memory.c | 151 ++++++++++++++++++++-------------------------------- 1 files changed, 59 insertions(+), 92 deletions(-) diff -puN mm/memory.c~ptwalk-remap_pfn_range mm/memory.c --- 25/mm/memory.c~ptwalk-remap_pfn_range 2005-03-09 16:34:09.000000000 -0800 +++ 25-akpm/mm/memory.c 2005-03-09 16:34:09.000000000 -0800 @@ -1089,97 +1089,74 @@ int zeromap_page_range(struct vm_area_st * mappings are removed. any references to nonexistent pages results * in null mappings (currently treated as "copy-on-access") */ -static inline void -remap_pte_range(struct mm_struct *mm, pte_t * pte, - unsigned long address, unsigned long size, - unsigned long pfn, pgprot_t prot) -{ - unsigned long base, end; - - base = address & PMD_MASK; - address &= ~PMD_MASK; - end = address + size; - if (end > PMD_SIZE) - end = PMD_SIZE; +static inline int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, + unsigned long addr, unsigned long end, + unsigned long pfn, pgprot_t prot) +{ + pte_t *pte; + + pte = pte_alloc_map(mm, pmd, addr); + if (!pte) + return -ENOMEM; do { BUG_ON(!pte_none(*pte)); if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn))) - set_pte_at(mm, base+address, pte, pfn_pte(pfn, prot)); - address += PAGE_SIZE; + set_pte_at(mm, addr, pte, pfn_pte(pfn, prot)); pfn++; - pte++; - } while (address && (address < end)); + } while (pte++, addr += PAGE_SIZE, addr != end); + pte_unmap(pte - 1); + return 0; } -static inline int -remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, - unsigned long size, unsigned long pfn, pgprot_t prot) -{ - unsigned long base, end; - - base = address & PUD_MASK; - address &= ~PUD_MASK; - end = address + size; - if (end > PUD_SIZE) - end = PUD_SIZE; - pfn -= (address >> PAGE_SHIFT); +static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, + unsigned long addr, unsigned long end, + unsigned long pfn, pgprot_t prot) +{ + pmd_t *pmd; + unsigned long next; + + pfn -= addr >> PAGE_SHIFT; + pmd = pmd_alloc(mm, pud, addr); + if (!pmd) + return -ENOMEM; do { - pte_t * pte = pte_alloc_map(mm, pmd, base + address); - if (!pte) + next = pmd_addr_end(addr, end); + if (remap_pte_range(mm, pmd, addr, next, + pfn + (addr >> PAGE_SHIFT), prot)) return -ENOMEM; - remap_pte_range(mm, pte, base + address, end - address, - (address >> PAGE_SHIFT) + pfn, prot); - pte_unmap(pte); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address && (address < end)); + } while (pmd++, addr = next, addr != end); return 0; } -static inline int remap_pud_range(struct mm_struct *mm, pud_t * pud, - unsigned long address, unsigned long size, - unsigned long pfn, pgprot_t prot) -{ - unsigned long base, end; - int error; - - base = address & PGDIR_MASK; - address &= ~PGDIR_MASK; - end = address + size; - if (end > PGDIR_SIZE) - end = PGDIR_SIZE; - pfn -= address >> PAGE_SHIFT; +static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd, + unsigned long addr, unsigned long end, + unsigned long pfn, pgprot_t prot) +{ + pud_t *pud; + unsigned long next; + + pfn -= addr >> PAGE_SHIFT; + pud = pud_alloc(mm, pgd, addr); + if (!pud) + return -ENOMEM; do { - pmd_t *pmd = pmd_alloc(mm, pud, base+address); - error = -ENOMEM; - if (!pmd) - break; - error = remap_pmd_range(mm, pmd, base + address, end - address, - (address >> PAGE_SHIFT) + pfn, prot); - if (error) - break; - address = (address + PUD_SIZE) & PUD_MASK; - pud++; - } while (address && (address < end)); - return error; + next = pud_addr_end(addr, end); + if (remap_pmd_range(mm, pud, addr, next, + pfn + (addr >> PAGE_SHIFT), prot)) + return -ENOMEM; + } while (pud++, addr = next, addr != end); + return 0; } /* Note: this is only safe if the mm semaphore is held when called. */ -int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, +int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t prot) { - int error = 0; pgd_t *pgd; - unsigned long beg = from; - unsigned long end = from + size; unsigned long next; + unsigned long end = addr + size; struct mm_struct *mm = vma->vm_mm; - int i; - - pfn -= from >> PAGE_SHIFT; - pgd = pgd_offset(mm, from); - flush_cache_range(vma, beg, end); - BUG_ON(from >= end); + int err; /* * Physically remapped pages are special. Tell the @@ -1191,31 +1168,21 @@ int remap_pfn_range(struct vm_area_struc */ vma->vm_flags |= VM_IO | VM_RESERVED; + BUG_ON(addr >= end); + pfn -= addr >> PAGE_SHIFT; + pgd = pgd_offset(mm, addr); + flush_cache_range(vma, addr, end); spin_lock(&mm->page_table_lock); - for (i = pgd_index(beg); i <= pgd_index(end-1); i++) { - pud_t *pud = pud_alloc(mm, pgd, from); - error = -ENOMEM; - if (!pud) - break; - next = (from + PGDIR_SIZE) & PGDIR_MASK; - if (next > end || next <= from) - next = end; - error = remap_pud_range(mm, pud, from, end - from, - pfn + (from >> PAGE_SHIFT), prot); - if (error) + do { + next = pgd_addr_end(addr, end); + err = remap_pud_range(mm, pgd, addr, next, + pfn + (addr >> PAGE_SHIFT), prot); + if (err) break; - from = next; - pgd++; - } - /* - * Why flush? remap_pte_range has a BUG_ON for !pte_none() - */ - flush_tlb_range(vma, beg, end); + } while (pgd++, addr = next, addr != end); spin_unlock(&mm->page_table_lock); - - return error; + return err; } - EXPORT_SYMBOL(remap_pfn_range); /* _