vserver 1.9.3

[linux-2.6.git] / arch / ppc64 / mm / imalloc.c

diff --git a/arch/ppc64/mm/imalloc.c b/arch/ppc64/mm/imalloc.c
index 2399f3f..9d92b0d 100644 (file)
--- a/arch/ppc64/mm/imalloc.c
+++ b/arch/ppc64/mm/imalloc.c
@@ -37,33 +37,51 @@ static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
        return 0;
 }
 
+/* Return whether the region described by v_addr and size is a subset
+ * of the region described by parent
+ */
+static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
+                       struct vm_struct *parent)
+{
+       return (int) (v_addr >= (unsigned long) parent->addr &&
+                     v_addr < (unsigned long) parent->addr + parent->size &&
+                     size < parent->size);
+}
+
+/* Return whether the region described by v_addr and size is a superset
+ * of the region described by child
+ */
+static int im_region_is_superset(unsigned long v_addr, unsigned long size,
+               struct vm_struct *child)
+{
+       struct vm_struct parent;
+
+       parent.addr = (void *) v_addr;
+       parent.size = size;
+
+       return im_region_is_subset((unsigned long) child->addr, child->size,
+                       &parent);
+}
+
 /* Return whether the region described by v_addr and size overlaps
- * the region described by vm.  Overlapping regions meet the 
+ * the region described by vm.  Overlapping regions meet the
  * following conditions:
  * 1) The regions share some part of the address space
  * 2) The regions aren't identical
- * 3) The first region is not a subset of the second
+ * 3) Neither region is a subset of the other
  */
-static inline int im_region_overlaps(unsigned long v_addr, unsigned long size,
+static int im_region_overlaps(unsigned long v_addr, unsigned long size,
                     struct vm_struct *vm)
 {
+       if (im_region_is_superset(v_addr, size, vm))
+               return 0;
+
        return (v_addr + size > (unsigned long) vm->addr + vm->size &&
                v_addr < (unsigned long) vm->addr + vm->size) ||
               (v_addr < (unsigned long) vm->addr &&
                v_addr + size > (unsigned long) vm->addr);
 }
 
-/* Return whether the region described by v_addr and size is a subset
- * of the region described by vm
- */
-static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
-                       struct vm_struct *vm)
-{
-       return (int) (v_addr >= (unsigned long) vm->addr && 
-                     v_addr < (unsigned long) vm->addr + vm->size &&
-                     size < vm->size);
-}
-
 /* Determine imalloc status of region described by v_addr and size.
  * Can return one of the following:
  * IM_REGION_UNUSED   -  Entire region is unallocated in imalloc space.
@@ -73,28 +91,37 @@ static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
  * IM_REGION_EXISTS -    Exact region already allocated in imalloc space.
  *                       vm will be assigned to a ptr to the existing imlist
  *                       member.
- * IM_REGION_OVERLAPS -  A portion of the region is already allocated in 
- *                       imalloc space.
+ * IM_REGION_OVERLAPS -  Region overlaps an allocated region in imalloc space.
+ * IM_REGION_SUPERSET -  Region is a superset of a region that is already
+ *                       allocated in imalloc space.
  */
-static int im_region_status(unsigned long v_addr, unsigned long size, 
+static int im_region_status(unsigned long v_addr, unsigned long size,
                    struct vm_struct **vm)
 {
        struct vm_struct *tmp;
 
-       for (tmp = imlist; tmp; tmp = tmp->next) 
-               if (v_addr < (unsigned long) tmp->addr + tmp->size) 
+       for (tmp = imlist; tmp; tmp = tmp->next)
+               if (v_addr < (unsigned long) tmp->addr + tmp->size)
                        break;
-                                       
+
        if (tmp) {
                if (im_region_overlaps(v_addr, size, tmp))
                        return IM_REGION_OVERLAP;
 
                *vm = tmp;
-               if (im_region_is_subset(v_addr, size, tmp))
+               if (im_region_is_subset(v_addr, size, tmp)) {
+                       /* Return with tmp pointing to superset */
                        return IM_REGION_SUBSET;
-               else if (v_addr == (unsigned long) tmp->addr && 
-                        size == tmp->size) 
+               }
+               if (im_region_is_superset(v_addr, size, tmp)) {
+                       /* Return with tmp pointing to first subset */
+                       return IM_REGION_SUPERSET;
+               }
+               else if (v_addr == (unsigned long) tmp->addr &&
+                        size == tmp->size) {
+                       /* Return with tmp pointing to exact region */
                        return IM_REGION_EXISTS;
+               }
        }
 
        *vm = NULL;
@@ -208,6 +235,10 @@ static struct vm_struct * __im_get_area(unsigned long req_addr,
                tmp = split_im_region(req_addr, size, tmp);
                break;
        case IM_REGION_EXISTS:
+               /* Return requested region */
+               break;
+       case IM_REGION_SUPERSET:
+               /* Return first existing subset of requested region */
                break;
        default:
                printk(KERN_ERR "%s() unexpected imalloc region status\n",