From 6698b2cae647bf633a91ec639c63c30619e4ec14 Mon Sep 17 00:00:00 2001
From: hselasky <hselasky@FreeBSD.org>
Date: Mon, 4 Nov 2019 14:19:09 +0000
Subject: [PATCH] Enable device class group attributes in the LinuxKPI.

Bump the __FreeBSD_version to force recompilation of
external kernel modules due to structure change.

Differential Revision:	https://reviews.freebsd.org/D21564
Submitted by:	Greg V <greg@unrelenting.technology>
MFC after:	1 week
Sponsored by:	Mellanox Technologies
---
 .../linuxkpi/common/include/linux/device.h    |  5 +++++
 .../linuxkpi/common/include/linux/sysfs.h     | 20 ++++++++++++++++---
 sys/sys/param.h                               |  2 +-
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/sys/compat/linuxkpi/common/include/linux/device.h b/sys/compat/linuxkpi/common/include/linux/device.h
index 0e8711f687e0..5361236baea8 100644
--- a/sys/compat/linuxkpi/common/include/linux/device.h
+++ b/sys/compat/linuxkpi/common/include/linux/device.h
@@ -54,6 +54,7 @@ struct class {
 	struct kobject	kobj;
 	devclass_t	bsdclass;
 	const struct dev_pm_ops *pm;
+	const struct attribute_group **dev_groups;
 	void		(*class_release)(struct class *class);
 	void		(*dev_release)(struct device *dev);
 	char *		(*devnode)(struct device *dev, umode_t *mode);
@@ -424,6 +425,8 @@ done:
 	kobject_init(&dev->kobj, &linux_dev_ktype);
 	kobject_add(&dev->kobj, &dev->class->kobj, dev_name(dev));
 
+	sysfs_create_groups(&dev->kobj, dev->class->dev_groups);
+
 	return (0);
 }
 
@@ -432,6 +435,8 @@ device_unregister(struct device *dev)
 {
 	device_t bsddev;
 
+	sysfs_remove_groups(&dev->kobj, dev->class->dev_groups);
+
 	bsddev = dev->bsddev;
 	dev->bsddev = NULL;
 
diff --git a/sys/compat/linuxkpi/common/include/linux/sysfs.h b/sys/compat/linuxkpi/common/include/linux/sysfs.h
index 164b9befbf5f..59e30f152f6e 100644
--- a/sys/compat/linuxkpi/common/include/linux/sysfs.h
+++ b/sys/compat/linuxkpi/common/include/linux/sysfs.h
@@ -62,12 +62,13 @@ struct attribute_group {
 
 #define	ATTRIBUTE_GROUPS(_name)						\
 	static struct attribute_group _name##_group = {			\
+		.name = __stringify(_name),				\
 		.attrs = _name##_attrs,					\
 	};								\
-	static struct attribute_group *_name##_groups[] = {		\
+	static const struct attribute_group *_name##_groups[] = {	\
 		&_name##_group,						\
 		NULL,							\
-	};
+	}
 
 /*
  * Handle our generic '\0' terminated 'C' string.
@@ -210,14 +211,27 @@ sysfs_create_groups(struct kobject *kobj, const struct attribute_group **grps)
 	int error = 0;
 	int i;
 
+	if (grps == NULL)
+		goto done;
 	for (i = 0; grps[i] && !error; i++)
 		error = sysfs_create_group(kobj, grps[i]);
 	while (error && --i >= 0)
 		sysfs_remove_group(kobj, grps[i]);
-
+done:
 	return (error);
 }
 
+static inline void
+sysfs_remove_groups(struct kobject *kobj, const struct attribute_group **grps)
+{
+	int i;
+
+	if (grps == NULL)
+		return;
+	for (i = 0; grps[i]; i++)
+		sysfs_remove_group(kobj, grps[i]);
+}
+
 static inline int
 sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp)
 {
diff --git a/sys/sys/param.h b/sys/sys/param.h
index dd987bb44ffd..7602bf89ff55 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -60,7 +60,7 @@
  *		in the range 5 to 9.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 1300054	/* Master, propagated to newvers */
+#define __FreeBSD_version 1300055	/* Master, propagated to newvers */
 
 /*
  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,