kernel.h: split out container_of() and typeof_member() macros

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt cleaning it up by splitting out container_of() and
typeof_member() macros.

For time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

Note, there are _a lot_ of headers and modules that include kernel.h
solely for one of these macros and this allows to unburden compiler for
the twisted inclusion paths and to make new code cleaner in the future.

Link: https://lkml.kernel.org/r/20211013170417.87909-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/container_of.h b/include/linux/container_of.h
new file mode 100644 (file)
index 0000000..dd56019
--- /dev/null
+++ b/include/linux/container_of.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CONTAINER_OF_H
+#define _LINUX_CONTAINER_OF_H
+
+#include <linux/build_bug.h>
+#include <linux/err.h>
+
+#define typeof_member(T, m)    typeof(((T*)0)->m)
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ * @ptr:       the pointer to the member.
+ * @type:      the type of the container struct this is embedded in.
+ * @member:    the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({                             \
+       void *__mptr = (void *)(ptr);                                   \
+       BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
+                        !__same_type(*(ptr), void),                    \
+                        "pointer type mismatch in container_of()");    \
+       ((type *)(__mptr - offsetof(type, member))); })
+
+/**
+ * container_of_safe - cast a member of a structure out to the containing structure
+ * @ptr:       the pointer to the member.
+ * @type:      the type of the container struct this is embedded in.
+ * @member:    the name of the member within the struct.
+ *
+ * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
+ */
+#define container_of_safe(ptr, type, member) ({                                \
+       void *__mptr = (void *)(ptr);                                   \
+       BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
+                        !__same_type(*(ptr), void),                    \
+                        "pointer type mismatch in container_of()");    \
+       IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) :                     \
+               ((type *)(__mptr - offsetof(type, member))); })
+
+#endif /* _LINUX_CONTAINER_OF_H */

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 471bc05936796fa70403bf23ad89dc3cb4abe936..ed4465757cec2ebc284adf6b874b71a82f8f958d 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -9,6 +9,7 @@
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <linux/container_of.h>
 #include <linux/bitops.h>
 #include <linux/kstrtox.h>
 #include <linux/log2.h>
@@ -52,8 +53,6 @@
 }                                      \
 )
 
-#define typeof_member(T, m)    typeof(((T*)0)->m)
-
 #define _RET_IP_               (unsigned long)__builtin_return_address(0)
 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
 
@@ -484,36 +483,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 #define __CONCAT(a, b) a ## b
 #define CONCATENATE(a, b) __CONCAT(a, b)
 
-/**
- * container_of - cast a member of a structure out to the containing structure
- * @ptr:       the pointer to the member.
- * @type:      the type of the container struct this is embedded in.
- * @member:    the name of the member within the struct.
- *
- */
-#define container_of(ptr, type, member) ({                             \
-       void *__mptr = (void *)(ptr);                                   \
-       BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
-                        !__same_type(*(ptr), void),                    \
-                        "pointer type mismatch in container_of()");    \
-       ((type *)(__mptr - offsetof(type, member))); })
-
-/**
- * container_of_safe - cast a member of a structure out to the containing structure
- * @ptr:       the pointer to the member.
- * @type:      the type of the container struct this is embedded in.
- * @member:    the name of the member within the struct.
- *
- * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
- */
-#define container_of_safe(ptr, type, member) ({                                \
-       void *__mptr = (void *)(ptr);                                   \
-       BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
-                        !__same_type(*(ptr), void),                    \
-                        "pointer type mismatch in container_of()");    \
-       IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) :                     \
-               ((type *)(__mptr - offsetof(type, member))); })
-
 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD