[PATCH] rpmsg: core: make rpmsg_class constant

From: Ricardo B. Marliere
Date: Tue Mar 05 2024 - 13:28:42 EST


Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the rpmsg_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
---
drivers/rpmsg/rpmsg_char.c | 2 +-
drivers/rpmsg/rpmsg_core.c | 16 +++++++++-------
drivers/rpmsg/rpmsg_ctrl.c | 2 +-
drivers/rpmsg/rpmsg_internal.h | 2 +-
4 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 1cb8d7474428..d7a342510902 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -423,7 +423,7 @@ static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev
init_waitqueue_head(&eptdev->readq);

device_initialize(dev);
- dev->class = rpmsg_class;
+ dev->class = &rpmsg_class;
dev->parent = parent;
dev->groups = rpmsg_eptdev_groups;
dev_set_drvdata(dev, eptdev);
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 4295c01a2861..0fa08266404d 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -20,7 +20,9 @@

#include "rpmsg_internal.h"

-struct class *rpmsg_class;
+const struct class rpmsg_class = {
+ .name = "rpmsg",
+};
EXPORT_SYMBOL(rpmsg_class);

/**
@@ -715,16 +717,16 @@ static int __init rpmsg_init(void)
{
int ret;

- rpmsg_class = class_create("rpmsg");
- if (IS_ERR(rpmsg_class)) {
- pr_err("failed to create rpmsg class\n");
- return PTR_ERR(rpmsg_class);
+ ret = class_register(&rpmsg_class);
+ if (ret) {
+ pr_err("failed to register rpmsg class\n");
+ return ret;
}

ret = bus_register(&rpmsg_bus);
if (ret) {
pr_err("failed to register rpmsg bus: %d\n", ret);
- class_destroy(rpmsg_class);
+ class_destroy(&rpmsg_class);
}
return ret;
}
@@ -733,7 +735,7 @@ postcore_initcall(rpmsg_init);
static void __exit rpmsg_fini(void)
{
bus_unregister(&rpmsg_bus);
- class_destroy(rpmsg_class);
+ class_destroy(&rpmsg_class);
}
module_exit(rpmsg_fini);

diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
index c312794ba4b3..28f57945ccd9 100644
--- a/drivers/rpmsg/rpmsg_ctrl.c
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -150,7 +150,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
dev = &ctrldev->dev;
device_initialize(dev);
dev->parent = &rpdev->dev;
- dev->class = rpmsg_class;
+ dev->class = &rpmsg_class;

mutex_init(&ctrldev->ctrl_lock);
cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index b950d6f790a3..a3ba768138f1 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -18,7 +18,7 @@
#define to_rpmsg_device(d) container_of(d, struct rpmsg_device, dev)
#define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv)

-extern struct class *rpmsg_class;
+extern const struct class rpmsg_class;

/**
* struct rpmsg_device_ops - indirection table for the rpmsg_device operations

---
base-commit: b03aa6d4e9a74c4289929b6cf3c6bcc80270682d
change-id: 20240305-class_cleanup-remoteproc-2b53e26b2817

Best regards,
--
Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>