[PATCH v2] OF: of_address: clean up OF stub & extern functions

[Randy Dunlap <rdunlap@infradead.org>]

Adjust <linux/of_address.h> so that stubs are present when
CONFIG_OF is not set *or* OF is set but OF_ADDRESS is not set.

This eliminates 2 build errors on arch/s390/ when HAS_IOMEM
is not set (so OF_ADDRESS is not set).
I.e., it provides a stub for of_iomap() when one was previously
not provided as well as removing some duplicate externs.

s390-linux-ld: drivers/irqchip/irq-al-fic.o: in function `al_fic_init_dt':
irq-al-fic.c:(.init.text+0x7a): undefined reference to `of_iomap'
s390-linux-ld: drivers/clocksource/timer-of.o: in function `timer_of_init':
timer-of.c:(.init.text+0xa4): undefined reference to `of_iomap'

Tested with many randconfig builds, but there could still be some
hidden problem here.

Fixes: 4acf4b9cd453 ("of: move of_address_to_resource and of_iomap declarations from sparc")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reported-by: kernel test robot <lkp@intel.com>
---
v2: handle SPARC as a special case since it provides its own versions of
    of_address_to_resource() and of_iomap();
    fix build errors reported by lkp/ktr and address comments from Laurent;
    do more randconfig build testing;

 include/linux/of_address.h |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

--- linux-next-20210524.orig/include/linux/of_address.h
+++ linux-next-20210524/include/linux/of_address.h
@@ -106,11 +106,12 @@ static inline bool of_dma_is_coherent(st
 }
 #endif /* CONFIG_OF_ADDRESS */
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_SPARC /* SPARC has its own versions of these */
 extern int of_address_to_resource(struct device_node *dev, int index,
 				  struct resource *r);
-void __iomem *of_iomap(struct device_node *node, int index);
-#else
+extern void __iomem *of_iomap(struct device_node *device, int index);
+#else /* !CONFIG_SPARC */
+#if (defined(CONFIG_OF) && !defined(CONFIG_OF_ADDRESS)) || !defined(CONFIG_OF)
 static inline int of_address_to_resource(struct device_node *dev, int index,
 					 struct resource *r)
 {
@@ -121,7 +122,9 @@ static inline void __iomem *of_iomap(str
 {
 	return NULL;
 }
-#endif
+#endif /* (defined(CONFIG_OF) && !defined(CONFIG_OF_ADDRESS)) || !defined(CONFIG_OF) */
+#endif /* CONFIG_SPARC */
+
 #define of_range_parser_init of_pci_range_parser_init
 
 #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)