+ /*
+ * Invalidate cache if we have more permissive parameters.
+ * cached_hole_size notes the largest hole noticed _below_
+ * the vmap_area cached in free_vmap_cache: if size fits
+ * into that hole, we want to scan from vstart to reuse
+ * the hole instead of allocating above free_vmap_cache.
+ * Note that __free_vmap_area may update free_vmap_cache
+ * without updating cached_hole_size or cached_align.
+ */
+ if (!free_vmap_cache ||
+ size < cached_hole_size ||
+ vstart < cached_vstart ||
+ align < cached_align) {
+nocache:
+ cached_hole_size = 0;
+ free_vmap_cache = NULL;
+ }
+ /* record if we encounter less permissive parameters */
+ cached_vstart = vstart;
+ cached_align = align;
+
+ /* find starting point for our search */
+ if (free_vmap_cache) {
+ first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ addr = ALIGN(first->va_end + PAGE_SIZE, align);
+ if (addr < vstart)
+ goto nocache;
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ } else {
+ addr = ALIGN(vstart, align);
+ if (addr + size - 1 < addr)
+ goto overflow;