[PATCH v2 1/4] resource: Add resource set range and size helpers

[Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>]

Setting the end address for a resource with a given size lacks a helper
and is therefore coded manually unlike the getter side which has a
helper for resource size calculation. Also, almost all callsites that
calculate the end address for a resource also set the start address
right before it like this:

	res->start = start_addr;
	res->end = res->start + size - 1;

Thus, add resource_set_range(res, start_addr, size) that sets the start
address and calculates the end address to simplify this often repeated
fragment. In addition, introduce resource_set_size() for the cases
where setting the start address of the resource is not necessary but
mention in its kerneldoc resource_set_range() is preferred when setting
both addresses.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
 include/linux/ioport.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index db7fe25f3370..2a1d33ad151c 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -216,6 +216,38 @@ struct resource *lookup_resource(struct resource *root, resource_size_t start);
 int adjust_resource(struct resource *res, resource_size_t start,
 		    resource_size_t size);
 resource_size_t resource_alignment(struct resource *res);
+
+/**
+ * resource_set_size - Calculates resource end address from size and start address
+ * @res: The resource descriptor
+ * @size: The size of the resource
+ *
+ * Calculates the end address for @res based on @size.
+ *
+ * Note: The start address of @res must be set when calling this function.
+ * Use resource_set_range() if setting both the start address and @size.
+ */
+static inline void resource_set_size(struct resource *res, resource_size_t size)
+{
+	res->end = res->start + size - 1;
+}
+
+/**
+ * resource_set_range - Sets resource start and end addresses
+ * @res: The resource descriptor
+ * @start: The start address for the resource
+ * @size: The size of the resource
+ *
+ * Sets @res start address and calculates the end address based on @size.
+ */
+static inline void resource_set_range(struct resource *res,
+				      resource_size_t start,
+				      resource_size_t size)
+{
+	res->start = start;
+	resource_set_size(res, size);
+}
+
 static inline resource_size_t resource_size(const struct resource *res)
 {
 	return res->end - res->start + 1;
-- 
2.39.2