1 files changed, 132 insertions, 26 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index 74af2d7cb5a1..414d6fc9131e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -362,35 +362,21 @@ int allocate_resource(struct resource *root, struct resource *new,
 
 EXPORT_SYMBOL(allocate_resource);
 
-/**
- * insert_resource - Inserts a resource in the resource tree
- * @parent: parent of the new resource
- * @new: new resource to insert
- *
- * Returns 0 on success, -EBUSY if the resource can't be inserted.
- *
- * This function is equivalent to request_resource when no conflict
- * happens. If a conflict happens, and the conflicting resources
- * entirely fit within the range of the new resource, then the new
- * resource is inserted and the conflicting resources become children of
- * the new resource.
+/*
+ * Insert a resource into the resource tree. If successful, return NULL,
+ * otherwise return the conflicting resource (compare to __request_resource())
  */
-int insert_resource(struct resource *parent, struct resource *new)
+static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 {
-        int result;
         struct resource *first, *next;
 
-        write_lock(&resource_lock);
-
         for (;; parent = first) {
-                result = 0;
                 first = __request_resource(parent, new);
                 if (!first)
-                        goto out;
+                        return first;
 
-                result = -EBUSY;
                 if (first == parent)
-                        goto out;
+                        return first;
 
                 if ((first->start > new->start) || (first->end < new->end))
                         break;
@@ -401,15 +387,13 @@ int insert_resource(struct resource *parent, struct resource *new)
         for (next = first; ; next = next->sibling) {
                 /* Partial overlap? Bad, and unfixable */
                 if (next->start < new->start || next->end > new->end)
-                        goto out;
+                        return next;
                 if (!next->sibling)
                         break;
                 if (next->sibling->start > new->end)
                         break;
         }
 
-        result = 0;
-
         new->parent = parent;
         new->sibling = next->sibling;
         new->child = first;
@@ -426,10 +410,64 @@ int insert_resource(struct resource *parent, struct resource *new)
                         next = next->sibling;
                 next->sibling = new;
         }
+        return NULL;
+}
 
- out:
+/**
+ * insert_resource - Inserts a resource in the resource tree
+ * @parent: parent of the new resource
+ * @new: new resource to insert
+ *
+ * Returns 0 on success, -EBUSY if the resource can't be inserted.
+ *
+ * This function is equivalent to request_resource when no conflict
+ * happens. If a conflict happens, and the conflicting resources
+ * entirely fit within the range of the new resource, then the new
+ * resource is inserted and the conflicting resources become children of
+ * the new resource.
+ */
+int insert_resource(struct resource *parent, struct resource *new)
+{
+        struct resource *conflict;
+
+        write_lock(&resource_lock);
+        conflict = __insert_resource(parent, new);
+        write_unlock(&resource_lock);
+        return conflict ? -EBUSY : 0;
+}
+
+/**
+ * insert_resource_expand_to_fit - Insert a resource into the resource tree
+ * @root: root resource descriptor
+ * @new: new resource to insert
+ *
+ * Insert a resource into the resource tree, possibly expanding it in order
+ * to make it encompass any conflicting resources.
+ */
+void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
+{
+        if (new->parent)
+                return;
+
+        write_lock(&resource_lock);
+        for (;;) {
+                struct resource *conflict;
+
+                conflict = __insert_resource(root, new);
+                if (!conflict)
+                        break;
+                if (conflict == root)
+                        break;
+
+                /* Ok, expand resource to cover the conflict, then try again .. */
+                if (conflict->start < new->start)
+                        new->start = conflict->start;
+                if (conflict->end > new->end)
+                        new->end = conflict->end;
+
+                printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
+        }
         write_unlock(&resource_lock);
-        return result;
 }
 
 /**
@@ -478,6 +516,74 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t
         return result;
 }
 
+static void __init __reserve_region_with_split(struct resource *root,
+                resource_size_t start, resource_size_t end,
+                const char *name)
+{
+        struct resource *parent = root;
+        struct resource *conflict;
+        struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
+
+        if (!res)
+                return;
+
+        res->name = name;
+        res->start = start;
+        res->end = end;
+        res->flags = IORESOURCE_BUSY;
+
+        for (;;) {
+                conflict = __request_resource(parent, res);
+                if (!conflict)
+                        break;
+                if (conflict != parent) {
+                        parent = conflict;
+                        if (!(conflict->flags & IORESOURCE_BUSY))
+                                continue;
+                }
+
+                /* Uhhuh, that didn't work out.. */
+                kfree(res);
+                res = NULL;
+                break;
+        }
+
+        if (!res) {
+                printk(KERN_DEBUG "    __reserve_region_with_split: (%s) [%llx, %llx], res: (%s) [%llx, %llx]\n",
+                         conflict->name, conflict->start, conflict->end,
+                         name, start, end);
+
+                /* failed, split and try again */
+
+                /* conflict coverred whole area */
+                if (conflict->start <= start && conflict->end >= end)
+                        return;
+
+                if (conflict->start > start)
+                        __reserve_region_with_split(root, start, conflict->start-1, name);
+                if (!(conflict->flags & IORESOURCE_BUSY)) {
+                        resource_size_t common_start, common_end;
+
+                        common_start = max(conflict->start, start);
+                        common_end = min(conflict->end, end);
+                        if (common_start < common_end)
+                                __reserve_region_with_split(root, common_start, common_end, name);
+                }
+                if (conflict->end < end)
+                        __reserve_region_with_split(root, conflict->end+1, end, name);
+        }
+
+}
+
+void reserve_region_with_split(struct resource *root,
+                resource_size_t start, resource_size_t end,
+                const char *name)
+{
+        write_lock(&resource_lock);
+        __reserve_region_with_split(root, start, end, name);
+        write_unlock(&resource_lock);
+}
+
 EXPORT_SYMBOL(adjust_resource);
 
 /**
@@ -490,7 +596,7 @@ resource_size_t resource_alignment(struct resource *res)
 {
         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
         case IORESOURCE_SIZEALIGN:
-                return res->end - res->start + 1;
+                return resource_size(res);
         case IORESOURCE_STARTALIGN:
                 return res->start;
         default: