diff mbox series

[v3,2/7] kernel.h: Split out container_of() and typeof_member() macros

Message ID 20211007150339.28910-3-andriy.shevchenko@linux.intel.com (mailing list archive)
State New
Headers show
Series kernel.h further split | expand

Commit Message

Andy Shevchenko Oct. 7, 2021, 3:03 p.m. UTC 
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.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 include/linux/container_of.h | 37 ++++++++++++++++++++++++++++++++++++
 include/linux/kernel.h       | 31 +-----------------------------
 include/linux/kobject.h      |  1 +
 3 files changed, 39 insertions(+), 30 deletions(-)
 create mode 100644 include/linux/container_of.h

Comments

Greg Kroah-Hartman Oct. 7, 2021, 3:09 p.m. UTC | #1 
On Thu, Oct 07, 2021 at 06:03:34PM +0300, Andy Shevchenko wrote:
> 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.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  include/linux/container_of.h | 37 ++++++++++++++++++++++++++++++++++++
>  include/linux/kernel.h       | 31 +-----------------------------
>  include/linux/kobject.h      |  1 +

Why did you touch kobject.h here?

It shouldn't have been needed to change for this commit.

Anyway, I really don't think this is all worth any more work at all, as
I'm not going to be the one taking it...

thanks,

greg k-h
Andy Shevchenko Oct. 7, 2021, 3:28 p.m. UTC | #2 
On Thu, Oct 07, 2021 at 05:09:09PM +0200, Greg Kroah-Hartman wrote:
> On Thu, Oct 07, 2021 at 06:03:34PM +0300, Andy Shevchenko wrote:

...

> Why did you touch kobject.h here?

Because it uses it, but indirectly. Now we may include it directly.

> It shouldn't have been needed to change for this commit.

OK. I will split it to a separate change. Would it be okay?

> Anyway, I really don't think this is all worth any more work at all,
>	as
> I'm not going to be the one taking it...

It's fine. There are more people in favour of this change anyway.

Thanks for review!
diff mbox series

Patch

diff --git a/include/linux/container_of.h b/include/linux/container_of.h
new file mode 100644
index 000000000000..f6ee1be0e784
--- /dev/null
+++ b/include/linux/container_of.h
@@ -0,0 +1,37 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CONTAINER_OF_H
+#define _LINUX_CONTAINER_OF_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 d416fe3165cb..ad9fdcce9dcf 100644
--- 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>
@@ -482,36 +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
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index efd56f990a46..bf8371e58b17 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -15,6 +15,7 @@ 
 #ifndef _KOBJECT_H_
 #define _KOBJECT_H_
 
+#include <linux/container_of.h>
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/sysfs.h>