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

From: Greg Kroah-Hartman
Date: Tue Jun 20 2023 - 10:41:47 EST


From: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>

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.

Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Cc: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
Cc: Xuezhi Zhang <zhangxuezhi1@xxxxxxxxxxx>
Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/comedi/comedi_fops.c | 47 ++++++++++++++--------------
drivers/comedi/drivers/comedi_test.c | 23 +++++++-------
2 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index 8e43918d38c4..1548dea15df1 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -97,7 +97,6 @@ static DEFINE_MUTEX(comedi_subdevice_minor_table_lock);
static struct comedi_subdevice
*comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS];

-static struct class *comedi_class;
static struct cdev comedi_cdev;

static void comedi_device_init(struct comedi_device *dev)
@@ -187,18 +186,6 @@ static struct comedi_device *comedi_clear_board_minor(unsigned int minor)
return dev;
}

-static void comedi_free_board_dev(struct comedi_device *dev)
-{
- if (dev) {
- comedi_device_cleanup(dev);
- if (dev->class_dev) {
- device_destroy(comedi_class,
- MKDEV(COMEDI_MAJOR, dev->minor));
- }
- comedi_dev_put(dev);
- }
-}
-
static struct comedi_subdevice *
comedi_subdevice_from_minor(const struct comedi_device *dev, unsigned int minor)
{
@@ -611,6 +598,23 @@ static struct attribute *comedi_dev_attrs[] = {
};
ATTRIBUTE_GROUPS(comedi_dev);

+static const struct class comedi_class = {
+ .name = "comedi",
+ .dev_groups = comedi_dev_groups,
+};
+
+static void comedi_free_board_dev(struct comedi_device *dev)
+{
+ if (dev) {
+ comedi_device_cleanup(dev);
+ if (dev->class_dev) {
+ device_destroy(&comedi_class,
+ MKDEV(COMEDI_MAJOR, dev->minor));
+ }
+ comedi_dev_put(dev);
+ }
+}
+
static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s,
unsigned int bits)
{
@@ -3263,7 +3267,7 @@ struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
return ERR_PTR(-EBUSY);
}
dev->minor = i;
- csdev = device_create(comedi_class, hardware_device,
+ csdev = device_create(&comedi_class, hardware_device,
MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i);
if (!IS_ERR(csdev))
dev->class_dev = get_device(csdev);
@@ -3312,7 +3316,7 @@ int comedi_alloc_subdevice_minor(struct comedi_subdevice *s)
}
i += COMEDI_NUM_BOARD_MINORS;
s->minor = i;
- csdev = device_create(comedi_class, dev->class_dev,
+ csdev = device_create(&comedi_class, dev->class_dev,
MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i",
dev->minor, s->index);
if (!IS_ERR(csdev))
@@ -3337,7 +3341,7 @@ void comedi_free_subdevice_minor(struct comedi_subdevice *s)
comedi_subdevice_minor_table[i] = NULL;
mutex_unlock(&comedi_subdevice_minor_table_lock);
if (s->class_dev) {
- device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
+ device_destroy(&comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
s->class_dev = NULL;
}
}
@@ -3383,15 +3387,12 @@ static int __init comedi_init(void)
if (retval)
goto out_unregister_chrdev_region;

- comedi_class = class_create("comedi");
- if (IS_ERR(comedi_class)) {
- retval = PTR_ERR(comedi_class);
+ retval = class_register(&comedi_class);
+ if (retval) {
pr_err("failed to create class\n");
goto out_cdev_del;
}

- comedi_class->dev_groups = comedi_dev_groups;
-
/* create devices files for legacy/manual use */
for (i = 0; i < comedi_num_legacy_minors; i++) {
struct comedi_device *dev;
@@ -3413,7 +3414,7 @@ static int __init comedi_init(void)

out_cleanup_board_minors:
comedi_cleanup_board_minors();
- class_destroy(comedi_class);
+ class_unregister(&comedi_class);
out_cdev_del:
cdev_del(&comedi_cdev);
out_unregister_chrdev_region:
@@ -3425,7 +3426,7 @@ module_init(comedi_init);
static void __exit comedi_cleanup(void)
{
comedi_cleanup_board_minors();
- class_destroy(comedi_class);
+ class_unregister(&comedi_class);
cdev_del(&comedi_cdev);
unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);

diff --git a/drivers/comedi/drivers/comedi_test.c b/drivers/comedi/drivers/comedi_test.c
index c02dc19a679b..30ea8b53ebf8 100644
--- a/drivers/comedi/drivers/comedi_test.c
+++ b/drivers/comedi/drivers/comedi_test.c
@@ -60,7 +60,9 @@
static bool config_mode;
static unsigned int set_amplitude;
static unsigned int set_period;
-static struct class *ctcls;
+static const struct class ctcls = {
+ .name = CLASS_NAME,
+};
static struct device *ctdev;

module_param_named(noauto, config_mode, bool, 0444);
@@ -795,13 +797,13 @@ static int __init comedi_test_init(void)
}

if (!config_mode) {
- ctcls = class_create(CLASS_NAME);
- if (IS_ERR(ctcls)) {
+ ret = class_register(&ctcls);
+ if (ret) {
pr_warn("comedi_test: unable to create class\n");
goto clean3;
}

- ctdev = device_create(ctcls, NULL, MKDEV(0, 0), NULL, DEV_NAME);
+ ctdev = device_create(&ctcls, NULL, MKDEV(0, 0), NULL, DEV_NAME);
if (IS_ERR(ctdev)) {
pr_warn("comedi_test: unable to create device\n");
goto clean2;
@@ -817,13 +819,10 @@ static int __init comedi_test_init(void)
return 0;

clean:
- device_destroy(ctcls, MKDEV(0, 0));
+ device_destroy(&ctcls, MKDEV(0, 0));
clean2:
- class_destroy(ctcls);
- ctdev = NULL;
+ class_unregister(&ctcls);
clean3:
- ctcls = NULL;
-
return 0;
}
module_init(comedi_test_init);
@@ -833,9 +832,9 @@ static void __exit comedi_test_exit(void)
if (ctdev)
comedi_auto_unconfig(ctdev);

- if (ctcls) {
- device_destroy(ctcls, MKDEV(0, 0));
- class_destroy(ctcls);
+ if (class_is_registered(&ctcls)) {
+ device_destroy(&ctcls, MKDEV(0, 0));
+ class_unregister(&ctcls);
}

comedi_driver_unregister(&waveform_driver);
--
2.41.0