git: 6841b9987e83 - main - LinuxKPI: add container_of_const()

The branch main has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=6841b9987e83fdd9a5b05ceafc20811469222d8b

commit 6841b9987e83fdd9a5b05ceafc20811469222d8b
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2025-04-24 09:25:21 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2025-04-24 22:13:54 +0000

    LinuxKPI: add container_of_const()
    
    Implement container_of_const() needed for wireless driver updates.
    
    Sponsored by:   The FreeBSD Foundation
    MFC after:      3 days
    Reviewed by:    emaste
    Differential Revision: https://reviews.freebsd.org/D49999
---
 sys/compat/linuxkpi/common/include/linux/container_of.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/container_of.h b/sys/compat/linuxkpi/common/include/linux/container_of.h
index 449507fcf9c1..7210d531b055 100644
--- a/sys/compat/linuxkpi/common/include/linux/container_of.h
+++ b/sys/compat/linuxkpi/common/include/linux/container_of.h
@@ -41,6 +41,14 @@
 	(type *)((uintptr_t)__p - offsetof(type, member));	\
 })
 
+#define	container_of_const(ptr, type, member)			\
+    _Generic(ptr,						\
+	const typeof(*(ptr)) *:					\
+	    (const type *)container_of(ptr, type, member),	\
+	default:						\
+	    container_of(ptr, type, member)			\
+    )
+
 #define	typeof_member(type, member)	__typeof(((type *)0)->member)
 
 #endif