[PATCH 4/7] resource: Use typedef for alignf callback

[Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>]

To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
 drivers/pci/bus.c      | 10 ++--------
 include/linux/ioport.h | 22 ++++++++++++++++++----
 include/linux/pci.h    |  5 +----
 kernel/resource.c      |  8 ++------
 4 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 9c2137dae429..be5a4bb4d2fb 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -176,10 +176,7 @@ static void pci_clip_resource_to_region(struct pci_bus *bus,
 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 		resource_size_t size, resource_size_t align,
 		resource_size_t min, unsigned long type_mask,
-		resource_size_t (*alignf)(void *,
-					  const struct resource *,
-					  resource_size_t,
-					  resource_size_t),
+		resource_alignf alignf,
 		void *alignf_data,
 		struct pci_bus_region *region)
 {
@@ -250,10 +247,7 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 		resource_size_t size, resource_size_t align,
 		resource_size_t min, unsigned long type_mask,
-		resource_size_t (*alignf)(void *,
-					  const struct resource *,
-					  resource_size_t,
-					  resource_size_t),
+		resource_alignf alignf,
 		void *alignf_data)
 {
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 14f5cfabbbc8..ce02f45e9c2c 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -188,6 +188,23 @@ enum {
 #define DEFINE_RES_DMA(_dma)						\
 	DEFINE_RES_DMA_NAMED((_dma), NULL)
 
+/**
+ * resource_alignf - Resource alignment callback
+ * @data:	Private data used by the callback
+ * @res:	Resource candidate range (an empty resource slot)
+ * @size:	The minimum size of the empty slot
+ * @align:	Alignment from the constraints
+ *
+ * Callback allows calculating resource placement and alignment beyond min,
+ * max, and align fields in the struct resource_constraint.
+ *
+ * Return: Start address for the resource.
+ */
+typedef resource_size_t (*resource_alignf)(void *data,
+					   const struct resource *res,
+					   resource_size_t size,
+					   resource_size_t align);
+
 /* PC/ISA/whatever - the normal PC address spaces: IO and memory */
 extern struct resource ioport_resource;
 extern struct resource iomem_resource;
@@ -207,10 +224,7 @@ extern void arch_remove_reservations(struct resource *avail);
 extern int allocate_resource(struct resource *root, struct resource *new,
 			     resource_size_t size, resource_size_t min,
 			     resource_size_t max, resource_size_t align,
-			     resource_size_t (*alignf)(void *,
-						       const struct resource *,
-						       resource_size_t,
-						       resource_size_t),
+			     resource_alignf alignf,
 			     void *alignf_data);
 struct resource *lookup_resource(struct resource *root, resource_size_t start);
 int adjust_resource(struct resource *res, resource_size_t start,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 60ca768bc867..d635e64debd9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1546,10 +1546,7 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
 			struct resource *res, resource_size_t size,
 			resource_size_t align, resource_size_t min,
 			unsigned long type_mask,
-			resource_size_t (*alignf)(void *,
-						  const struct resource *,
-						  resource_size_t,
-						  resource_size_t),
+			resource_alignf alignf,
 			void *alignf_data);
 
 
diff --git a/kernel/resource.c b/kernel/resource.c
index ed4bb8ad701a..9d7920104120 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -60,8 +60,7 @@ EXPORT_SYMBOL(iomem_resource);
  */
 struct resource_constraint {
 	resource_size_t min, max, align;
-	resource_size_t (*alignf)(void *, const struct resource *,
-			resource_size_t, resource_size_t);
+	resource_alignf alignf;
 	void *alignf_data;
 };
 
@@ -725,10 +724,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
 int allocate_resource(struct resource *root, struct resource *new,
 		      resource_size_t size, resource_size_t min,
 		      resource_size_t max, resource_size_t align,
-		      resource_size_t (*alignf)(void *,
-						const struct resource *,
-						resource_size_t,
-						resource_size_t),
+		      resource_alignf alignf,
 		      void *alignf_data)
 {
 	int err;
-- 
2.30.2