sound: make all 'class' structures const

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: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Ivan Orlov <ivan.orlov0322@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: alsa-devel@alsa-project.org
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230620175633.641141-2-gregkh@linuxfoundation.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/sound/core.h b/include/sound/core.h
index 4ea5f66b59d75fd2f048f62b744f7260b5eb15e2..f6e0dd648b80c2728b2bd904be2245b18a09126e 100644 (file)
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -232,7 +232,7 @@ static inline struct device *snd_card_get_device_link(struct snd_card *card)
 
 extern int snd_major;
 extern int snd_ecards_limit;
-extern struct class *sound_class;
+extern const struct class sound_class;
 #ifdef CONFIG_SND_DEBUG
 extern struct dentry *sound_debugfs_root;
 #endif

diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index 3cadd40100f3e538a3834d177c024ede838d3117..ee77547bf8dcb5ec0e169018c3428cd55e2a371d 100644 (file)
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -737,7 +737,7 @@ static int __init snd_ctl_led_init(void)
        unsigned int group;
 
        device_initialize(&snd_ctl_led_dev);
-       snd_ctl_led_dev.class = sound_class;
+       snd_ctl_led_dev.class = &sound_class;
        snd_ctl_led_dev.release = snd_ctl_led_dev_release;
        dev_set_name(&snd_ctl_led_dev, "ctl-led");
        if (device_add(&snd_ctl_led_dev)) {

diff --git a/sound/core/init.c b/sound/core/init.c
index df0c22480375a558a635d1c8ea1bb74c1ad37fe0..baef2688d0cf1a5661b568238138e2068da1421c 100644 (file)
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -129,7 +129,7 @@ void snd_device_initialize(struct device *dev, struct snd_card *card)
        device_initialize(dev);
        if (card)
                dev->parent = &card->card_dev;
-       dev->class = sound_class;
+       dev->class = &sound_class;
        dev->release = default_release;
 }
 EXPORT_SYMBOL_GPL(snd_device_initialize);
@@ -331,7 +331,7 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
 
        device_initialize(&card->card_dev);
        card->card_dev.parent = parent;
-       card->card_dev.class = sound_class;
+       card->card_dev.class = &sound_class;
        card->card_dev.release = release_card_device;
        card->card_dev.groups = card->dev_groups;
        card->dev_groups[0] = &card_dev_attr_group;

diff --git a/sound/sound_core.c b/sound/sound_core.c
index 4f6911274d56488d85e10724e1327f1b91041acb..d81fed1c122699e4a94189878f38ca5785de9f45 100644 (file)
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -23,9 +23,6 @@ static inline int init_oss_soundcore(void)    { return 0; }
 static inline void cleanup_oss_soundcore(void) { }
 #endif
 
-struct class *sound_class;
-EXPORT_SYMBOL(sound_class);
-
 MODULE_DESCRIPTION("Core sound module");
 MODULE_AUTHOR("Alan Cox");
 MODULE_LICENSE("GPL");
@@ -37,6 +34,12 @@ static char *sound_devnode(const struct device *dev, umode_t *mode)
        return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
 }
 
+const struct class sound_class = {
+       .name = "sound",
+       .devnode = sound_devnode,
+};
+EXPORT_SYMBOL(sound_class);
+
 static int __init init_soundcore(void)
 {
        int rc;
@@ -45,21 +48,19 @@ static int __init init_soundcore(void)
        if (rc)
                return rc;
 
-       sound_class = class_create("sound");
-       if (IS_ERR(sound_class)) {
+       rc = class_register(&sound_class);
+       if (rc) {
                cleanup_oss_soundcore();
-               return PTR_ERR(sound_class);
+               return rc;
        }
 
-       sound_class->devnode = sound_devnode;
-
        return 0;
 }
 
 static void __exit cleanup_soundcore(void)
 {
        cleanup_oss_soundcore();
-       class_destroy(sound_class);
+       class_unregister(&sound_class);
 }
 
 subsys_initcall(init_soundcore);
@@ -276,7 +277,7 @@ retry:
                }
        }
 
-       device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
+       device_create(&sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
                      NULL, "%s", s->name+6);
        return s->unit_minor;
 
@@ -302,7 +303,7 @@ static void sound_remove_unit(struct sound_unit **list, int unit)
                if (!preclaim_oss)
                        __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
                                            p->name);
-               device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
+               device_destroy(&sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
                kfree(p);
        }
 }