Re: [PATCH] of: fix of_address_to_resource and of_iomap undefined

On Sat, 4 Sept 2021 at 04:23, Rob Herring [off-list ref] wrote:

On Thu, Sep 2, 2021 at 4:27 AM Chunyan Zhang [off-list ref] wrote:

quoted

From: Chunyan Zhang <redacted>

If CONFIG_OF is selected, but CONFIG_OF_ADDRESS is not, when compiling
files (sunch as timer_of.c) in which the function of_iomap() is invoked,
compiler would report 'undefined reference to of_iomap', the same case
is for of_address_to_resource().

What arch and config are you building?

sparc, and the config is attached.

quoted

This patch also makes sure that of_iomap() and of_address_to_resource()
are declared for sparc so that sparc can have its specific
implementations in arch/sparc/kernel/of_device_common.c, even if
including include/linux/of_address.h in it.

Signed-off-by: Chunyan Zhang <redacted>
---
 include/linux/of_address.h | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 45598dbec269..02a719d58466 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h

@@ -80,6 +80,23 @@ static inline u64 of_translate_address(struct device_node *np,
        return OF_BAD_ADDR;
 }

+#ifdef CONFIG_SPARC
+extern int of_address_to_resource(struct device_node *dev, int index,
+                                 struct resource *r);
+void __iomem *of_iomap(struct device_node *device, int index);

This is now in the !CONFIG_OF_ADDRESS section. So for
CONFIG_OF_ADDRESS, we'd never have a function declaration.

Not sure I got your point.
There are these two function declarations both in
arch/sparc/kernel/of_device_common.c (CONFIG_SPARC &&
!CONFIG_OF_ADDRESS) and drivers/of/address.c (!CONFIG_SPARC &&
CONFIG_OF_ADDRESS).

This change does not look right at all to me.

quoted

+#else
+static inline int of_address_to_resource(struct device_node *dev, int index,
+                                        struct resource *r)
+{
+       return -EINVAL;
+}
+
+static inline void __iomem *of_iomap(struct device_node *device, int index)
+{
+       return NULL;
+}
+#endif

Now, I'm also not sure if this change is right, I learned in another
patch recently that Linus prefers to avoid the extra code like this.

https://lkml.org/lkml/2021/7/2/511

quoted

+
 static inline const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
                                             u64 *size, unsigned int *flags)
 {

@@ -124,22 +141,6 @@ static inline bool of_dma_is_coherent(struct device_node *np)
 }
 #endif /* CONFIG_OF_ADDRESS */

-#ifdef CONFIG_OF
-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
-static inline int of_address_to_resource(struct device_node *dev, int index,
-                                        struct resource *r)
-{
-       return -EINVAL;
-}
-
-static inline void __iomem *of_iomap(struct device_node *device, int index)
-{
-       return NULL;
-}
-#endif
 #define of_range_parser_init of_pci_range_parser_init

 static inline const __be32 *of_get_address(struct device_node *dev, int index,
--

2.25.1