[PATCH 2/2] mips: sibyte: make tb_class constant

From: Ricardo B. Marliere
Date: Tue Mar 05 2024 - 08:38:36 EST


Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the tb_class structure to be declared at build time placing
it into read-only memory, instead of having to be dynamically allocated at
boot time.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
---
KTODO: use device_register instead of device_create?
---
arch/mips/sibyte/common/sb_tbprof.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/arch/mips/sibyte/common/sb_tbprof.c b/arch/mips/sibyte/common/sb_tbprof.c
index 408db45efdc8..af5333986900 100644
--- a/arch/mips/sibyte/common/sb_tbprof.c
+++ b/arch/mips/sibyte/common/sb_tbprof.c
@@ -535,13 +535,14 @@ static const struct file_operations sbprof_tb_fops = {
.llseek = default_llseek,
};

-static struct class *tb_class;
+static const struct class tb_class = {
+ .name = "sb_tracebuffer",
+};
static struct device *tb_dev;

static int __init sbprof_tb_init(void)
{
struct device *dev;
- struct class *tbc;
int err;

if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
@@ -550,15 +551,11 @@ static int __init sbprof_tb_init(void)
return -EIO;
}

- tbc = class_create("sb_tracebuffer");
- if (IS_ERR(tbc)) {
- err = PTR_ERR(tbc);
+ err = class_register(&tb_class);
+ if (err)
goto out_chrdev;
- }
-
- tb_class = tbc;

- dev = device_create(tbc, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
+ dev = device_create(&tb_class, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
if (IS_ERR(dev)) {
err = PTR_ERR(dev);
goto out_class;
@@ -573,7 +570,7 @@ static int __init sbprof_tb_init(void)
return 0;

out_class:
- class_destroy(tb_class);
+ class_unregister(&tb_class);
out_chrdev:
unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);

@@ -582,9 +579,9 @@ static int __init sbprof_tb_init(void)

static void __exit sbprof_tb_cleanup(void)
{
- device_destroy(tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
+ device_destroy(&tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
- class_destroy(tb_class);
+ class_unregister(&tb_class);
}

module_init(sbprof_tb_init);

--
2.43.0