Re: [PATCH] platform/x86: wmi-bmof: Make use of .bin_size() callback

[Armin Wolf <W_Armin@gmx.de>]

Am 10.12.24 um 15:47 schrieb Ilpo Järvinen:

> On Fri, 6 Dec 2024, Armin Wolf wrote:
>
>> Until now the wmi-bmof driver had to allocate the binary sysfs
>> attribute dynamically since its size depends on the bmof buffer
>> returned by the firmware.
>>
>> Use the new .bin_size() callback to avoid having to do this memory
>> allocation.
>>
>> Tested on a Asus Prime B650-Plus.
>>
>> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
>> ---
>>   drivers/platform/x86/wmi-bmof.c | 75 +++++++++++++++++----------------
>>   1 file changed, 38 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/platform/x86/wmi-bmof.c b/drivers/platform/x86/wmi-bmof.c
>> index df6f0ae6e6c7..3e33da36da8a 100644
>> --- a/drivers/platform/x86/wmi-bmof.c
>> +++ b/drivers/platform/x86/wmi-bmof.c
>> @@ -20,66 +20,66 @@
>>
>>   #define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
>>
>> -struct bmof_priv {
>> -	union acpi_object *bmofdata;
>> -	struct bin_attribute bmof_bin_attr;
>> -};
>> -
>> -static ssize_t read_bmof(struct file *filp, struct kobject *kobj, struct bin_attribute *attr,
>> +static ssize_t bmof_read(struct file *filp, struct kobject *kobj, const struct bin_attribute *attr,
>>   			 char *buf, loff_t off, size_t count)
>>   {
>> -	struct bmof_priv *priv = container_of(attr, struct bmof_priv, bmof_bin_attr);
>> +	struct device *dev = kobj_to_dev(kobj);
>> +	union acpi_object *obj = dev_get_drvdata(dev);
>>
>> -	return memory_read_from_buffer(buf, count, &off, priv->bmofdata->buffer.pointer,
>> -				       priv->bmofdata->buffer.length);
>> +	return memory_read_from_buffer(buf, count, &off, obj->buffer.pointer, obj->buffer.length);
>>   }
>>
>> -static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
>> +static const BIN_ATTR_ADMIN_RO(bmof, 0);
>> +
>> +static const struct bin_attribute * const bmof_attrs[] = {
>> +	&bin_attr_bmof,
>> +	NULL
>> +};
>> +
>> +static size_t bmof_bin_size(struct kobject *kobj, const struct bin_attribute *attr, int n)
>>   {
>> -	struct bmof_priv *priv;
>> -	int ret;
>> +	struct device *dev = kobj_to_dev(kobj);
>> +	union acpi_object *obj = dev_get_drvdata(dev);
>> +
>> +	return obj->buffer.length;
>> +}
>>
>> -	priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL);
>> -	if (!priv)
>> -		return -ENOMEM;
>> +static const struct attribute_group bmof_group = {
>> +	.bin_size = bmof_bin_size,
>> +	.bin_attrs_new = bmof_attrs,
>> +};
>> +
>> +static const struct attribute_group *bmof_groups[] = {
>> +	&bmof_group,
>> +	NULL
>> +};
>>
>> -	dev_set_drvdata(&wdev->dev, priv);
>> +static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
>> +{
>> +	union acpi_object *obj;
>>
>> -	priv->bmofdata = wmidev_block_query(wdev, 0);
>> -	if (!priv->bmofdata) {
>> +	obj = wmidev_block_query(wdev, 0);
>> +	if (!obj) {
>>   		dev_err(&wdev->dev, "failed to read Binary MOF\n");
>>   		return -EIO;
>>   	}
>>
>> -	if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
>> +	if (obj->type != ACPI_TYPE_BUFFER) {
>>   		dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
>> -		ret = -EIO;
>> -		goto err_free;
>> +		kfree(obj);
>> +		return -EIO;
>>   	}
>>
>> -	sysfs_bin_attr_init(&priv->bmof_bin_attr);
>> -	priv->bmof_bin_attr.attr.name = "bmof";
>> -	priv->bmof_bin_attr.attr.mode = 0400;
>> -	priv->bmof_bin_attr.read = read_bmof;
>> -	priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
>> -
>> -	ret = device_create_bin_file(&wdev->dev, &priv->bmof_bin_attr);
>> -	if (ret)
>> -		goto err_free;
>> +	dev_set_drvdata(&wdev->dev, obj);
>>
>>   	return 0;
>> -
>> - err_free:
>> -	kfree(priv->bmofdata);
>> -	return ret;
>>   }
>>
>>   static void wmi_bmof_remove(struct wmi_device *wdev)
>>   {
>> -	struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
>> +	union acpi_object *obj = dev_get_drvdata(&wdev->dev);
>>
>> -	device_remove_bin_file(&wdev->dev, &priv->bmof_bin_attr);
>> -	kfree(priv->bmofdata);
>> +	kfree(obj);
>>   }
>>
>>   static const struct wmi_device_id wmi_bmof_id_table[] = {
>> @@ -90,6 +90,7 @@ static const struct wmi_device_id wmi_bmof_id_table[] = {
>>   static struct wmi_driver wmi_bmof_driver = {
>>   	.driver = {
>>   		.name = "wmi-bmof",
>> +		.dev_groups = bmof_groups,
>>   	},
>>   	.probe = wmi_bmof_probe,
>>   	.remove = wmi_bmof_remove,
> So do I understand right that this meant to supercede the patch from
> Thomas?
>
Yes, i totally overlooked this patch, sorry. I will ask him to drop his patch.

Thanks,
Armin Wolf