Merge tag 'rtc-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

[linux.git] / kernel / resource.c

diff --git a/kernel/resource.c b/kernel/resource.c
index 158f04ec1d4fad91702c7c38a972f3f1775fb727..d22423e85cf801ba358581f08390041c0929a2cf 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -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"))