On 2023-08-10 at 21:22:08 +0400, Ivan Orlov wrote:
> Now that the driver core allows for struct class to be in read-only
> memory, move the fpga_bridge_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@xxxxxxxxxxxxxxxxxxx>
>
> Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
> ---
> drivers/fpga/fpga-bridge.c | 106 ++++++++++++++++++-------------------
> 1 file changed, 52 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
> index a6c25dee9cc1..6e38ddaf16cf 100644
> --- a/drivers/fpga/fpga-bridge.c
> +++ b/drivers/fpga/fpga-bridge.c
> @@ -14,7 +14,6 @@
> #include <linux/spinlock.h>
>
> static DEFINE_IDA(fpga_bridge_ida);
> -static struct class *fpga_bridge_class;
Could we still use the forward declaration, to avoid moving too
much code block.
>
> /* Lock for adding/removing bridges to linked lists*/
> static DEFINE_SPINLOCK(bridge_list_lock);
> @@ -84,6 +83,53 @@ static struct fpga_bridge *__fpga_bridge_get(struct device *dev,
> return ERR_PTR(ret);
> }
>
> +static ssize_t name_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct fpga_bridge *bridge = to_fpga_bridge(dev);
> +
> + return sprintf(buf, "%s\n", bridge->name);
> +}
> +
> +static ssize_t state_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct fpga_bridge *bridge = to_fpga_bridge(dev);
> + int state = 1;
> +
> + if (bridge->br_ops && bridge->br_ops->enable_show) {
> + state = bridge->br_ops->enable_show(bridge);
> + if (state < 0)
> + return state;
> + }
> +
> + return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
> +}
> +
> +static DEVICE_ATTR_RO(name);
> +static DEVICE_ATTR_RO(state);
> +
> +static struct attribute *fpga_bridge_attrs[] = {
> + &dev_attr_name.attr,
> + &dev_attr_state.attr,
> + NULL,
> +};
> +ATTRIBUTE_GROUPS(fpga_bridge);
> +
> +static void fpga_bridge_dev_release(struct device *dev)
> +{
> + struct fpga_bridge *bridge = to_fpga_bridge(dev);
> +
> + ida_free(&fpga_bridge_ida, bridge->dev.id);
> + kfree(bridge);
> +}
> +
> +static const struct class fpga_bridge_class = {
> + .name = "fpga_bridge",
> + .dev_groups = fpga_bridge_groups,
> + .dev_release = fpga_bridge_dev_release,
> +};
Insert them between __fpga_bridge_get() and of_fpga_bridge_get() is not
preferred. See below comments.
> +
> /**
> * of_fpga_bridge_get - get an exclusive reference to an fpga bridge
> *
> @@ -99,7 +145,7 @@ struct fpga_bridge *of_fpga_bridge_get(struct device_node *np,
> {
> struct device *dev;
>
> - dev = class_find_device_by_of_node(fpga_bridge_class, np);
> + dev = class_find_device_by_of_node(&fpga_bridge_class, np);
> if (!dev)
> return ERR_PTR(-ENODEV);
>
> @@ -126,7 +172,7 @@ struct fpga_bridge *fpga_bridge_get(struct device *dev,
> {
> struct device *bridge_dev;
>
> - bridge_dev = class_find_device(fpga_bridge_class, NULL, dev,
> + bridge_dev = class_find_device(&fpga_bridge_class, NULL, dev,
> fpga_bridge_dev_match);
> if (!bridge_dev)
> return ERR_PTR(-ENODEV);
> @@ -281,39 +327,6 @@ int fpga_bridge_get_to_list(struct device *dev,
> }
> EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);
>
> -static ssize_t name_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - struct fpga_bridge *bridge = to_fpga_bridge(dev);
> -
> - return sprintf(buf, "%s\n", bridge->name);
> -}
> -
> -static ssize_t state_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - struct fpga_bridge *bridge = to_fpga_bridge(dev);
> - int state = 1;
> -
> - if (bridge->br_ops && bridge->br_ops->enable_show) {
> - state = bridge->br_ops->enable_show(bridge);
> - if (state < 0)
> - return state;
> - }
> -
> - return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
> -}
> -
> -static DEVICE_ATTR_RO(name);
> -static DEVICE_ATTR_RO(state);
> -
> -static struct attribute *fpga_bridge_attrs[] = {
> - &dev_attr_name.attr,
> - &dev_attr_state.attr,
> - NULL,
> -};
> -ATTRIBUTE_GROUPS(fpga_bridge);
> -
> /**
> * fpga_bridge_register - create and register an FPGA Bridge device
> * @parent: FPGA bridge device from pdev
> @@ -359,7 +372,7 @@ fpga_bridge_register(struct device *parent, const char *name,
> bridge->priv = priv;
>
> bridge->dev.groups = br_ops->groups;
> - bridge->dev.class = fpga_bridge_class;
> + bridge->dev.class = &fpga_bridge_class;
> bridge->dev.parent = parent;
> bridge->dev.of_node = parent->of_node;
> bridge->dev.id = id;
> @@ -407,29 +420,14 @@ void fpga_bridge_unregister(struct fpga_bridge *bridge)
> }
> EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>
> -static void fpga_bridge_dev_release(struct device *dev)
> -{
> - struct fpga_bridge *bridge = to_fpga_bridge(dev);
> -
> - ida_free(&fpga_bridge_ida, bridge->dev.id);
> - kfree(bridge);
> -}
> -
How about put the fpga_bridge_class definition here?
Thanks,
Yilun
> static int __init fpga_bridge_dev_init(void)
> {
> - fpga_bridge_class = class_create("fpga_bridge");
> - if (IS_ERR(fpga_bridge_class))
> - return PTR_ERR(fpga_bridge_class);
> -
> - fpga_bridge_class->dev_groups = fpga_bridge_groups;
> - fpga_bridge_class->dev_release = fpga_bridge_dev_release;
> -
> - return 0;
> + return class_register(&fpga_bridge_class);
> }
>
> static void __exit fpga_bridge_dev_exit(void)
> {
> - class_destroy(fpga_bridge_class);
> + class_unregister(&fpga_bridge_class);
> ida_destroy(&fpga_bridge_ida);
> }
>
> --
> 2.34.1
>
