+ 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;
+ }
+ }