[PATCH v2] linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>

[Masahiro Yamada <masahiroy@xxxxxxxxxx>]

<linux/kconfig.h> is included from all the kernel-space source files,
including C, assembly, linker scripts. It is intended to contain a
minimal set of macros to evaluate CONFIG options.

IF_ENABLED() is an intruder here because (x ? y : z) is C code, which
should not be included from assembly files or linker scripts.

Also, <linux/kconfig.h> is no longer self-contained because NULL is
defined in <linux/stddef.h>.

Move IF_ENABLED() out to <linux/kernel.h> as PTR_IF(). PTF_IF()
takes the general boolean expression instead of a CONFIG option
so that it fits better in <linux/kernel.h>.

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

Changes in v2:
  - Keep PTF_IF macro in pinctrl-ingenic.c

 drivers/pinctrl/pinctrl-ingenic.c | 2 ++
 include/linux/kconfig.h           | 6 ------
 include/linux/kernel.h            | 2 ++
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-ingenic.c b/drivers/pinctrl/pinctrl-ingenic.c
index 651a36b9dcc0..0ee69f8e20b2 100644
--- a/drivers/pinctrl/pinctrl-ingenic.c
+++ b/drivers/pinctrl/pinctrl-ingenic.c
@@ -3854,6 +3854,8 @@ static int __init ingenic_pinctrl_probe(struct platform_device *pdev)
 	return 0;
 }
 
+#define IF_ENABLED(cfg, ptr)	PTR_IF(IS_ENABLED(cfg), (ptr))
+
 static const struct of_device_id ingenic_pinctrl_of_match[] = {
 	{
 		.compatible = "ingenic,jz4730-pinctrl",
diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index 24a59cb06963..cc8fa109cfa3 100644
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -70,10 +70,4 @@
  */
 #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
 
-/*
- * IF_ENABLED(CONFIG_FOO, ptr) evaluates to (ptr) if CONFIG_FOO is set to 'y'
- * or 'm', NULL otherwise.
- */
-#define IF_ENABLED(option, ptr) (IS_ENABLED(option) ? (ptr) : NULL)
-
 #endif /* __LINUX_KCONFIG_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5b7ed6dc99ac..8685ca4cf287 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -38,6 +38,8 @@
 #define PTR_ALIGN_DOWN(p, a)	((typeof(p))ALIGN_DOWN((unsigned long)(p), (a)))
 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
 
+#define PTR_IF(cond, ptr)	((cond) ? (ptr) : NULL)
+
 /* generic data direction definitions */
 #define READ			0
 #define WRITE			1
-- 
2.27.0