[PATCH] rapidio: make all 'class' structures const

From: Ivan Orlov
Date: Thu Aug 10 2023 - 15:51:18 EST


Now that the driver core allows for struct class to be in read-only
memory, making all 'class' structures to be declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at load time.

Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
---
drivers/rapidio/devices/rio_mport_cdev.c | 16 +++++++++-------
drivers/rapidio/rio_cm.c | 18 ++++++++++--------
2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index a115730ebf14..27afbb9d544b 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -250,7 +250,9 @@ static DEFINE_MUTEX(mport_devs_lock);
static DECLARE_WAIT_QUEUE_HEAD(mport_cdev_wait);
#endif

-static struct class *dev_class;
+static const struct class dev_class = {
+ .name = DRV_NAME,
+};
static dev_t dev_number;

static void mport_release_mapping(struct kref *ref);
@@ -2379,7 +2381,7 @@ static struct mport_dev *mport_cdev_add(struct rio_mport *mport)

device_initialize(&md->dev);
md->dev.devt = MKDEV(MAJOR(dev_number), mport->id);
- md->dev.class = dev_class;
+ md->dev.class = &dev_class;
md->dev.parent = &mport->dev;
md->dev.release = mport_device_release;
dev_set_name(&md->dev, DEV_NAME "%d", mport->id);
@@ -2600,10 +2602,10 @@ static int __init mport_init(void)
int ret;

/* Create device class needed by udev */
- dev_class = class_create(DRV_NAME);
- if (IS_ERR(dev_class)) {
+ ret = class_register(&dev_class);
+ if (ret) {
rmcd_error("Unable to create " DRV_NAME " class");
- return PTR_ERR(dev_class);
+ return ret;
}

ret = alloc_chrdev_region(&dev_number, 0, RIO_MAX_MPORTS, DRV_NAME);
@@ -2624,7 +2626,7 @@ static int __init mport_init(void)
err_cli:
unregister_chrdev_region(dev_number, RIO_MAX_MPORTS);
err_chr:
- class_destroy(dev_class);
+ class_unregister(&dev_class);
return ret;
}

@@ -2634,7 +2636,7 @@ static int __init mport_init(void)
static void __exit mport_exit(void)
{
class_interface_unregister(&rio_mport_interface);
- class_destroy(dev_class);
+ class_unregister(&dev_class);
unregister_chrdev_region(dev_number, RIO_MAX_MPORTS);
}

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index 49f8d111e546..9135227301c8 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -233,7 +233,9 @@ static DEFINE_IDR(ch_idr);
static LIST_HEAD(cm_dev_list);
static DECLARE_RWSEM(rdev_sem);

-static struct class *dev_class;
+static const struct class dev_class = {
+ .name = DRV_NAME,
+};
static unsigned int dev_major;
static unsigned int dev_minor_base;
static dev_t dev_number;
@@ -2072,7 +2074,7 @@ static int riocm_cdev_add(dev_t devno)
return ret;
}

- riocm_cdev.dev = device_create(dev_class, NULL, devno, NULL, DEV_NAME);
+ riocm_cdev.dev = device_create(&dev_class, NULL, devno, NULL, DEV_NAME);
if (IS_ERR(riocm_cdev.dev)) {
cdev_del(&riocm_cdev.cdev);
return PTR_ERR(riocm_cdev.dev);
@@ -2293,15 +2295,15 @@ static int __init riocm_init(void)
int ret;

/* Create device class needed by udev */
- dev_class = class_create(DRV_NAME);
- if (IS_ERR(dev_class)) {
+ ret = class_register(&dev_class);
+ if (ret) {
riocm_error("Cannot create " DRV_NAME " class");
- return PTR_ERR(dev_class);
+ return ret;
}

ret = alloc_chrdev_region(&dev_number, 0, 1, DRV_NAME);
if (ret) {
- class_destroy(dev_class);
+ class_unregister(&dev_class);
return ret;
}

@@ -2349,7 +2351,7 @@ static int __init riocm_init(void)
class_interface_unregister(&rio_mport_interface);
err_reg:
unregister_chrdev_region(dev_number, 1);
- class_destroy(dev_class);
+ class_unregister(&dev_class);
return ret;
}

@@ -2364,7 +2366,7 @@ static void __exit riocm_exit(void)
device_unregister(riocm_cdev.dev);
cdev_del(&(riocm_cdev.cdev));

- class_destroy(dev_class);
+ class_unregister(&dev_class);
unregister_chrdev_region(dev_number, 1);
}

--
2.34.1