Currently, the WMI driver core knows how many instances of a given
WMI object exist, but WMI drivers cannot access this information.
At the same time, some current and upcoming WMI drivers want to
have access to this information. Add wmi_instance_count() and
wmidev_instance_count() to allow WMI drivers to get the number of
WMI object instances.
Signed-off-by: Armin Wolf <[email protected]>
---
drivers/platform/x86/wmi.c | 40 ++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 2 ++
include/linux/wmi.h | 2 ++
3 files changed, 44 insertions(+)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index c226dd4163a1..7c1a904dec5f 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -263,6 +263,46 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length)
}
EXPORT_SYMBOL_GPL(set_required_buffer_size);
+/**
+ * wmi_instance_count - Get number of WMI object instances
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance_count: variable to hold the instance count
+ *
+ * Get the number of WMI object instances.
+ *
+ * Returns: acpi_status signaling success or error.
+ */
+acpi_status wmi_instance_count(const char *guid_string, u8 *instance_count)
+{
+ struct wmi_block *wblock;
+ acpi_status status;
+
+ status = find_guid(guid_string, &wblock);
+ if (ACPI_FAILURE(status))
+ return status;
+
+ *instance_count = wmidev_instance_count(&wblock->dev);
+
+ return AE_OK;
+}
+EXPORT_SYMBOL_GPL(wmi_instance_count);
+
+/**
+ * wmidev_instance_count - Get number of WMI object instances
+ * @wdev: A wmi bus device from a driver
+ *
+ * Get the number of WMI object instances.
+ *
+ * Returns: Number of WMI object instances.
+ */
+u8 wmidev_instance_count(struct wmi_device *wdev)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+
+ return wblock->gblock.instance_count;
+}
+EXPORT_SYMBOL_GPL(wmidev_instance_count);
+
/**
* wmi_evaluate_method - Evaluate a WMI method (deprecated)
* @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index efff750f326d..ab2a4b23e7a3 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -412,6 +412,8 @@ extern bool acpi_is_pnp_device(struct acpi_device *);
typedef void (*wmi_notify_handler) (u32 value, void *context);
+acpi_status wmi_instance_count(const char *guid, u8 *instance_count);
+
extern acpi_status wmi_evaluate_method(const char *guid, u8 instance,
u32 method_id,
const struct acpi_buffer *in,
diff --git a/include/linux/wmi.h b/include/linux/wmi.h
index c1a3bd4e4838..763bd382cf2d 100644
--- a/include/linux/wmi.h
+++ b/include/linux/wmi.h
@@ -35,6 +35,8 @@ extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev,
extern union acpi_object *wmidev_block_query(struct wmi_device *wdev,
u8 instance);
+u8 wmidev_instance_count(struct wmi_device *wdev);
+
extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
/**
--
2.30.2
On Wed, Apr 26, 2023 at 11:28:47PM +0200, Armin Wolf wrote:
> Currently, the WMI driver core knows how many instances of a given
> WMI object exist, but WMI drivers cannot access this information.
> At the same time, some current and upcoming WMI drivers want to
> have access to this information. Add wmi_instance_count() and
> wmidev_instance_count() to allow WMI drivers to get the number of
> WMI object instances.
>
> Signed-off-by: Armin Wolf <[email protected]>
Tested-by: James Seo <[email protected]>
Hi Armin,
Thank you for your work on this.
On 4/26/23 23:28, Armin Wolf wrote:
> Currently, the WMI driver core knows how many instances of a given
> WMI object exist, but WMI drivers cannot access this information.
> At the same time, some current and upcoming WMI drivers want to
> have access to this information. Add wmi_instance_count() and
> wmidev_instance_count() to allow WMI drivers to get the number of
> WMI object instances.
>
> Signed-off-by: Armin Wolf <[email protected]>
> ---
> drivers/platform/x86/wmi.c | 40 ++++++++++++++++++++++++++++++++++++++
> include/linux/acpi.h | 2 ++
> include/linux/wmi.h | 2 ++
> 3 files changed, 44 insertions(+)
>
> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
> index c226dd4163a1..7c1a904dec5f 100644
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> @@ -263,6 +263,46 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length)
> }
> EXPORT_SYMBOL_GPL(set_required_buffer_size);
>
> +/**
> + * wmi_instance_count - Get number of WMI object instances
> + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
> + * @instance_count: variable to hold the instance count
> + *
> + * Get the number of WMI object instances.
> + *
> + * Returns: acpi_status signaling success or error.
> + */
> +acpi_status wmi_instance_count(const char *guid_string, u8 *instance_count)
> +{
> + struct wmi_block *wblock;
> + acpi_status status;
> +
> + status = find_guid(guid_string, &wblock);
> + if (ACPI_FAILURE(status))
> + return status;
> +
> + *instance_count = wmidev_instance_count(&wblock->dev);
> +
> + return AE_OK;
> +}
> +EXPORT_SYMBOL_GPL(wmi_instance_count);
I would prefer this to have a normal kernel function prototype
which returns -errno rather then returning an acpi_status. E.g. :
/**
* wmi_instance_count - Get number of WMI object instances
* @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
*
* Get the number of WMI object instances.
*
* Returns: The number of WMI object instances, 0 if the GUID is not found.
*/
int wmi_instance_count(const char *guid_string)
{
struct wmi_block *wblock;
acpi_status status;
status = find_guid(guid_string, &wblock);
if (ACPI_FAILURE(status))
return 0;
return wmidev_instance_count(&wblock->dev);
}
EXPORT_SYMBOL_GPL(wmi_instance_count);
This will also allow this to completely replace
the get_instance_count() function in dell-wmi-sysman.
Note I have just gone with always returning 0 here
on error. I guess you could look at the status and
return 0 for not-found and -errno for other errors
but I don't think any callers will care for the difference,
so just always returning 0 seems easier for callers to
deal with.
As always this is just a suggestion, let me know if
you think this is a bad idea.
Regards,
Hans
> +
> +/**
> + * wmidev_instance_count - Get number of WMI object instances
> + * @wdev: A wmi bus device from a driver
> + *
> + * Get the number of WMI object instances.
> + *
> + * Returns: Number of WMI object instances.
> + */
> +u8 wmidev_instance_count(struct wmi_device *wdev)
> +{
> + struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
> +
> + return wblock->gblock.instance_count;
> +}
> +EXPORT_SYMBOL_GPL(wmidev_instance_count);
> +
> /**
> * wmi_evaluate_method - Evaluate a WMI method (deprecated)
> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index efff750f326d..ab2a4b23e7a3 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -412,6 +412,8 @@ extern bool acpi_is_pnp_device(struct acpi_device *);
>
> typedef void (*wmi_notify_handler) (u32 value, void *context);
>
> +acpi_status wmi_instance_count(const char *guid, u8 *instance_count);
> +
> extern acpi_status wmi_evaluate_method(const char *guid, u8 instance,
> u32 method_id,
> const struct acpi_buffer *in,
> diff --git a/include/linux/wmi.h b/include/linux/wmi.h
> index c1a3bd4e4838..763bd382cf2d 100644
> --- a/include/linux/wmi.h
> +++ b/include/linux/wmi.h
> @@ -35,6 +35,8 @@ extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev,
> extern union acpi_object *wmidev_block_query(struct wmi_device *wdev,
> u8 instance);
>
> +u8 wmidev_instance_count(struct wmi_device *wdev);
> +
> extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
>
> /**
> --
> 2.30.2
>
Am 27.04.23 um 11:43 schrieb Hans de Goede:
> Hi Armin,
>
> Thank you for your work on this.
>
> On 4/26/23 23:28, Armin Wolf wrote:
>> Currently, the WMI driver core knows how many instances of a given
>> WMI object exist, but WMI drivers cannot access this information.
>> At the same time, some current and upcoming WMI drivers want to
>> have access to this information. Add wmi_instance_count() and
>> wmidev_instance_count() to allow WMI drivers to get the number of
>> WMI object instances.
>>
>> Signed-off-by: Armin Wolf <[email protected]>
>> ---
>> drivers/platform/x86/wmi.c | 40 ++++++++++++++++++++++++++++++++++++++
>> include/linux/acpi.h | 2 ++
>> include/linux/wmi.h | 2 ++
>> 3 files changed, 44 insertions(+)
>>
>> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
>> index c226dd4163a1..7c1a904dec5f 100644
>> --- a/drivers/platform/x86/wmi.c
>> +++ b/drivers/platform/x86/wmi.c
>> @@ -263,6 +263,46 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length)
>> }
>> EXPORT_SYMBOL_GPL(set_required_buffer_size);
>>
>> +/**
>> + * wmi_instance_count - Get number of WMI object instances
>> + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
>> + * @instance_count: variable to hold the instance count
>> + *
>> + * Get the number of WMI object instances.
>> + *
>> + * Returns: acpi_status signaling success or error.
>> + */
>> +acpi_status wmi_instance_count(const char *guid_string, u8 *instance_count)
>> +{
>> + struct wmi_block *wblock;
>> + acpi_status status;
>> +
>> + status = find_guid(guid_string, &wblock);
>> + if (ACPI_FAILURE(status))
>> + return status;
>> +
>> + *instance_count = wmidev_instance_count(&wblock->dev);
>> +
>> + return AE_OK;
>> +}
>> +EXPORT_SYMBOL_GPL(wmi_instance_count);
> I would prefer this to have a normal kernel function prototype
> which returns -errno rather then returning an acpi_status. E.g. :
>
> /**
> * wmi_instance_count - Get number of WMI object instances
> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
> *
> * Get the number of WMI object instances.
> *
> * Returns: The number of WMI object instances, 0 if the GUID is not found.
> */
> int wmi_instance_count(const char *guid_string)
> {
> struct wmi_block *wblock;
> acpi_status status;
>
> status = find_guid(guid_string, &wblock);
> if (ACPI_FAILURE(status))
> return 0;
>
> return wmidev_instance_count(&wblock->dev);
> }
> EXPORT_SYMBOL_GPL(wmi_instance_count);
>
> This will also allow this to completely replace
> the get_instance_count() function in dell-wmi-sysman.
>
> Note I have just gone with always returning 0 here
> on error. I guess you could look at the status and
> return 0 for not-found and -errno for other errors
> but I don't think any callers will care for the difference,
> so just always returning 0 seems easier for callers to
> deal with.
>
> As always this is just a suggestion, let me know if
> you think this is a bad idea.
>
> Regards,
>
> Hans
>
I like this idea. Returning a negative errno on error would allow drivers to
distinguish between "WMI object not found" and "zero instances found", which
might be useful for some drivers.
Maybe a function for converting ACPI errors to POSIX errors already exists,
otherwise i will just write one myself.
Armin Wolf
>
>> +
>> +/**
>> + * wmidev_instance_count - Get number of WMI object instances
>> + * @wdev: A wmi bus device from a driver
>> + *
>> + * Get the number of WMI object instances.
>> + *
>> + * Returns: Number of WMI object instances.
>> + */
>> +u8 wmidev_instance_count(struct wmi_device *wdev)
>> +{
>> + struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
>> +
>> + return wblock->gblock.instance_count;
>> +}
>> +EXPORT_SYMBOL_GPL(wmidev_instance_count);
>> +
>> /**
>> * wmi_evaluate_method - Evaluate a WMI method (deprecated)
>> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>> index efff750f326d..ab2a4b23e7a3 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -412,6 +412,8 @@ extern bool acpi_is_pnp_device(struct acpi_device *);
>>
>> typedef void (*wmi_notify_handler) (u32 value, void *context);
>>
>> +acpi_status wmi_instance_count(const char *guid, u8 *instance_count);
>> +
>> extern acpi_status wmi_evaluate_method(const char *guid, u8 instance,
>> u32 method_id,
>> const struct acpi_buffer *in,
>> diff --git a/include/linux/wmi.h b/include/linux/wmi.h
>> index c1a3bd4e4838..763bd382cf2d 100644
>> --- a/include/linux/wmi.h
>> +++ b/include/linux/wmi.h
>> @@ -35,6 +35,8 @@ extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev,
>> extern union acpi_object *wmidev_block_query(struct wmi_device *wdev,
>> u8 instance);
>>
>> +u8 wmidev_instance_count(struct wmi_device *wdev);
>> +
>> extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
>>
>> /**
>> --
>> 2.30.2
>>
Hi,
On 4/27/23 18:26, Armin Wolf wrote:
> Am 27.04.23 um 11:43 schrieb Hans de Goede:
>
>> Hi Armin,
>>
>> Thank you for your work on this.
>>
>> On 4/26/23 23:28, Armin Wolf wrote:
>>> Currently, the WMI driver core knows how many instances of a given
>>> WMI object exist, but WMI drivers cannot access this information.
>>> At the same time, some current and upcoming WMI drivers want to
>>> have access to this information. Add wmi_instance_count() and
>>> wmidev_instance_count() to allow WMI drivers to get the number of
>>> WMI object instances.
>>>
>>> Signed-off-by: Armin Wolf <[email protected]>
>>> ---
>>> drivers/platform/x86/wmi.c | 40 ++++++++++++++++++++++++++++++++++++++
>>> include/linux/acpi.h | 2 ++
>>> include/linux/wmi.h | 2 ++
>>> 3 files changed, 44 insertions(+)
>>>
>>> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
>>> index c226dd4163a1..7c1a904dec5f 100644
>>> --- a/drivers/platform/x86/wmi.c
>>> +++ b/drivers/platform/x86/wmi.c
>>> @@ -263,6 +263,46 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length)
>>> }
>>> EXPORT_SYMBOL_GPL(set_required_buffer_size);
>>>
>>> +/**
>>> + * wmi_instance_count - Get number of WMI object instances
>>> + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
>>> + * @instance_count: variable to hold the instance count
>>> + *
>>> + * Get the number of WMI object instances.
>>> + *
>>> + * Returns: acpi_status signaling success or error.
>>> + */
>>> +acpi_status wmi_instance_count(const char *guid_string, u8 *instance_count)
>>> +{
>>> + struct wmi_block *wblock;
>>> + acpi_status status;
>>> +
>>> + status = find_guid(guid_string, &wblock);
>>> + if (ACPI_FAILURE(status))
>>> + return status;
>>> +
>>> + *instance_count = wmidev_instance_count(&wblock->dev);
>>> +
>>> + return AE_OK;
>>> +}
>>> +EXPORT_SYMBOL_GPL(wmi_instance_count);
>> I would prefer this to have a normal kernel function prototype
>> which returns -errno rather then returning an acpi_status. E.g. :
>>
>> /**
>> * wmi_instance_count - Get number of WMI object instances
>> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
>> *
>> * Get the number of WMI object instances.
>> *
>> * Returns: The number of WMI object instances, 0 if the GUID is not found.
>> */
>> int wmi_instance_count(const char *guid_string)
>> {
>> struct wmi_block *wblock;
>> acpi_status status;
>>
>> status = find_guid(guid_string, &wblock);
>> if (ACPI_FAILURE(status))
>> return 0;
>>
>> return wmidev_instance_count(&wblock->dev);
>> }
>> EXPORT_SYMBOL_GPL(wmi_instance_count);
>>
>> This will also allow this to completely replace
>> the get_instance_count() function in dell-wmi-sysman.
>>
>> Note I have just gone with always returning 0 here
>> on error. I guess you could look at the status and
>> return 0 for not-found and -errno for other errors
>> but I don't think any callers will care for the difference,
>> so just always returning 0 seems easier for callers to
>> deal with.
>>
>> As always this is just a suggestion, let me know if
>> you think this is a bad idea.
>>
>> Regards,
>>
>> Hans
>>
> I like this idea. Returning a negative errno on error would allow drivers to
> distinguish between "WMI object not found" and "zero instances found", which
> might be useful for some drivers.
>
> Maybe a function for converting ACPI errors to POSIX errors already exists,
> otherwise i will just write one myself.
Ok, that sounds good to me. I'm looking forward to a non RFC submission
of these changes.
Regards,
Hans