1 files changed, 49 insertions, 12 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index 7b36976e5dea..798e2fae2a06 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -357,6 +357,32 @@ int __weak page_is_ram(unsigned long pfn)
         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 }
 
+void __weak arch_remove_reservations(struct resource *avail)
+{
+}
+
+static resource_size_t simple_align_resource(void *data,
+                                             const struct resource *avail,
+                                             resource_size_t size,
+                                             resource_size_t align)
+{
+        return avail->start;
+}
+
+static void resource_clip(struct resource *res, resource_size_t min,
+                          resource_size_t max)
+{
+        if (res->start < min)
+                res->start = min;
+        if (res->end > max)
+                res->end = max;
+}
+
+static bool resource_contains(struct resource *res1, struct resource *res2)
+{
+        return res1->start <= res2->start && res1->end >= res2->end;
+}
+
 /*
  * Find empty slot in the resource tree given range and alignment.
  */
@@ -370,8 +396,9 @@ static int find_resource(struct resource *root, struct resource *new,
                          void *alignf_data)
 {
         struct resource *this = root->child;
-        struct resource tmp = *new;
+        struct resource tmp = *new, avail, alloc;
 
+        tmp.flags = new->flags;
         tmp.start = root->start;
         /*
          * Skip past an allocated resource that starts at 0, since the assignment
@@ -386,17 +413,22 @@ static int find_resource(struct resource *root, struct resource *new,
                         tmp.end = this->start - 1;
                 else
                         tmp.end = root->end;
-                if (tmp.start < min)
-                        tmp.start = min;
-                if (tmp.end > max)
-                        tmp.end = max;
-                tmp.start = ALIGN(tmp.start, align);
-                if (alignf)
-                        tmp.start = alignf(alignf_data, &tmp, size, align);
-                if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
-                        new->start = tmp.start;
-                        new->end = tmp.start + size - 1;
-                        return 0;
+
+                resource_clip(&tmp, min, max);
+                arch_remove_reservations(&tmp);
+
+                /* Check for overflow after ALIGN() */
+                avail = *new;
+                avail.start = ALIGN(tmp.start, align);
+                avail.end = tmp.end;
+                if (avail.start >= tmp.start) {
+                        alloc.start = alignf(alignf_data, &avail, size, align);
+                        alloc.end = alloc.start + size - 1;
+                        if (resource_contains(&avail, &alloc)) {
+                                new->start = alloc.start;
+                                new->end = alloc.end;
+                                return 0;
+                        }
                 }
                 if (!this)
                         break;
@@ -428,6 +460,9 @@ int allocate_resource(struct resource *root, struct resource *new,
 {
         int err;
 
+        if (!alignf)
+                alignf = simple_align_resource;
+
         write_lock(&resource_lock);
         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
         if (err >= 0 && __request_resource(root, new))
@@ -453,6 +488,8 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
 
                 if (first == parent)
                         return first;
+                if (WARN_ON(first == new))      /* duplicated insertion */
+                        return first;
 
                 if ((first->start > new->start) || (first->end < new->end))
                         break;