fpga: region: make fpga_region_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the fpga_region_class structure to be declared at build
time placing it into read-only memory, instead of having to be
dynamically allocated at boot time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230811073043.52808-3-ivan.orlov0322@gmail.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index c9d065a..b364a92 100644 (file)
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -16,7 +16,7 @@
 #include <linux/spinlock.h>
 
 static DEFINE_IDA(fpga_region_ida);
-static struct class *fpga_region_class;
+static const struct class fpga_region_class;
 
 struct fpga_region *
 fpga_region_class_find(struct device *start, const void *data,
@@ -24,7 +24,7 @@ fpga_region_class_find(struct device *start, const void *data,
 {
        struct device *dev;
 
-       dev = class_find_device(fpga_region_class, start, data, match);
+       dev = class_find_device(&fpga_region_class, start, data, match);
        if (!dev)
                return NULL;
 
@@ -217,7 +217,7 @@ fpga_region_register_full(struct device *parent, const struct fpga_region_info *
        mutex_init(&region->mutex);
        INIT_LIST_HEAD(&region->bridge_list);
 
-       region->dev.class = fpga_region_class;
+       region->dev.class = &fpga_region_class;
        region->dev.parent = parent;
        region->dev.of_node = parent->of_node;
        region->dev.id = id;
@@ -288,6 +288,12 @@ static void fpga_region_dev_release(struct device *dev)
        kfree(region);
 }
 
+static const struct class fpga_region_class = {
+       .name = "fpga_region",
+       .dev_groups = fpga_region_groups,
+       .dev_release = fpga_region_dev_release,
+};
+
 /**
  * fpga_region_init - creates the fpga_region class.
  *
@@ -295,19 +301,12 @@ static void fpga_region_dev_release(struct device *dev)
  */
 static int __init fpga_region_init(void)
 {
-       fpga_region_class = class_create("fpga_region");
-       if (IS_ERR(fpga_region_class))
-               return PTR_ERR(fpga_region_class);
-
-       fpga_region_class->dev_groups = fpga_region_groups;
-       fpga_region_class->dev_release = fpga_region_dev_release;
-
-       return 0;
+       return class_register(&fpga_region_class);
 }
 
 static void __exit fpga_region_exit(void)
 {
-       class_destroy(fpga_region_class);
+       class_unregister(&fpga_region_class);
        ida_destroy(&fpga_region_ida);
 }