The usage of the macro allows to remove the custom handler function,
saving some memory. Additionally the code is easier to read.

While at it also mark the attribute as __ro_after_init, as the only
modification happens in the __init phase.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 drivers/of/fdt.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0121100372b41d44d841784b863af5492f19c31e..4b1e9f101ce34d7212cc8de99c7e7761a2636866 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1264,18 +1264,9 @@ void __init unflatten_and_copy_device_tree(void)
 }
 
 #ifdef CONFIG_SYSFS
-static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
-			       struct bin_attribute *bin_attr,
-			       char *buf, loff_t off, size_t count)
-{
-	memcpy(buf, initial_boot_params + off, count);
-	return count;
-}
-
 static int __init of_fdt_raw_init(void)
 {
-	static struct bin_attribute of_fdt_raw_attr =
-		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
+	static __ro_after_init BIN_ATTR_SIMPLE_ADMIN_RO(fdt);
 
 	if (!initial_boot_params)
 		return 0;
@@ -1285,8 +1276,9 @@ static int __init of_fdt_raw_init(void)
 		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
 		return 0;
 	}
-	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
-	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
+	bin_attr_fdt.private = initial_boot_params;
+	bin_attr_fdt.size = fdt_totalsize(initial_boot_params);
+	return sysfs_create_bin_file(firmware_kobj, &bin_attr_fdt);
 }
 late_initcall(of_fdt_raw_init);
 #endif

---
base-commit: 28eb75e178d389d325f1666e422bc13bbbb9804c
change-id: 20241122-sysfs-const-bin_attr-of-7765932a946d

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>

On Fri, 22 Nov 2024 13:14:00 +0100, Thomas Weißschuh wrote:
> The usage of the macro allows to remove the custom handler function,
> saving some memory. Additionally the code is easier to read.
> 
> While at it also mark the attribute as __ro_after_init, as the only
> modification happens in the __init phase.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
>  drivers/of/fdt.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
> 

Applied, thanks!