resource: fix locking in find_next_iomem_res()

[thirdparty/kernel/stable.git] / kernel / resource.c

diff --git a/kernel/resource.c b/kernel/resource.c
index 158f04ec1d4fad91702c7c38a972f3f1775fb727..3ced0cd45bdd5132d21c72c2121d04cc848646dd 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -326,7 +326,7 @@ EXPORT_SYMBOL(release_resource);
  *
  * If a resource is found, returns 0 and @*res is overwritten with the part
  * of the resource that's within [@start..@end]; if none is found, returns
- * -1 or -EINVAL for other invalid parameters.
+ * -ENODEV.  Returns -EINVAL for invalid parameters.
  *
  * This function walks the whole tree and not just first level children
  * unless @first_lvl is true.
@@ -365,16 +365,16 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
                        break;
        }
 
+       if (p) {
+               /* copy data */
+               res->start = max(start, p->start);
+               res->end = min(end, p->end);
+               res->flags = p->flags;
+               res->desc = p->desc;
+       }
+
        read_unlock(&resource_lock);
-       if (!p)
-               return -1;
-
-       /* copy data */
-       res->start = max(start, p->start);
-       res->end = min(end, p->end);
-       res->flags = p->flags;
-       res->desc = p->desc;
-       return 0;
+       return p ? 0 : -ENODEV;
 }
 
 static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
@@ -1628,6 +1628,45 @@ void resource_list_free(struct list_head *head)
 }
 EXPORT_SYMBOL(resource_list_free);
 
+#ifdef CONFIG_DEVICE_PRIVATE
+/**
+ * devm_request_free_mem_region - find free region for device private memory
+ *
+ * @dev: device struct to bind the resource to
+ * @size: size in bytes of the device memory to add
+ * @base: resource tree to look in
+ *
+ * This function tries to find an empty range of physical address big enough to
+ * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
+ * memory, which in turn allocates struct pages.
+ */
+struct resource *devm_request_free_mem_region(struct device *dev,
+               struct resource *base, unsigned long size)
+{
+       resource_size_t end, addr;
+       struct resource *res;
+
+       size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
+       end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
+       addr = end - size + 1UL;
+
+       for (; addr > size && addr >= base->start; addr -= size) {
+               if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
+                               REGION_DISJOINT)
+                       continue;
+
+               res = devm_request_mem_region(dev, addr, size, dev_name(dev));
+               if (!res)
+                       return ERR_PTR(-ENOMEM);
+               res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
+               return res;
+       }
+
+       return ERR_PTR(-ERANGE);
+}
+EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
+#endif /* CONFIG_DEVICE_PRIVATE */
+
 static int __init strict_iomem(char *str)
 {
        if (strstr(str, "relaxed"))