From: Hugh Dickins <hugh@veritas.com>
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 <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
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);
/*
_