Unverified Commit 7e2d964f authored by Armin Wolf's avatar Armin Wolf Committed by Ilpo Järvinen
Browse files

platform/wmi: Add wmidev_invoke_procedure() 



Some WMI methods return no values, so the whole postprocessing
of the result data is not needed for them. Add a special function
for calling such WMI methods to prepare for future changes of
the main wmidev_invoke_method() function.

Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20260406203237.2970-2-W_Armin@gmx.de


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent 0ec7f158

Documentation/wmi/driver-development-guide.rst

+2 −1
Original line number Diff line number Diff line
@@ -106,7 +106,8 @@ WMI method drivers 


WMI drivers can call WMI device methods using wmidev_invoke_method(). For each WMI method

invocation the WMI driver needs to provide the instance number and the method ID, as well as

a buffer with the method arguments and optionally a buffer for the results.

a buffer with the method arguments and optionally a buffer for the results. When calling WMI

methods that do not return any values, wmidev_invoke_procedure() should be used instead.



The layout of said buffers is device-specific and described by the Binary MOF data associated

with a given WMI device. Said Binary MOF data also describes the method ID of a given WMI method

drivers/platform/wmi/core.c

+44 −0
Original line number Diff line number Diff line
@@ -427,6 +427,50 @@ int wmidev_invoke_method(struct wmi_device *wdev, u8 instance, u32 method_id, 
}

EXPORT_SYMBOL_GPL(wmidev_invoke_method);



/**

 * wmidev_invoke_procedure - Invoke a WMI method that does not return values

 * @wdev: A wmi bus device from a driver

 * @instance: Instance index

 * @method_id: Method ID to call

 * @in: Mandatory WMI buffer containing input for the method call

 *

 * Invoke a WMI method that does not return any values. Use wmidev_invoke_method()

 * for WMI methods that do return values.

 *

 * Return: 0 on success or negative error code on failure.

 */

int wmidev_invoke_procedure(struct wmi_device *wdev, u8 instance, u32 method_id,

			    const struct wmi_buffer *in)

{

	struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);

	struct acpi_buffer ain;

	acpi_status status;

	int ret;



	if (wblock->gblock.flags & ACPI_WMI_STRING) {

		ret = wmi_marshal_string(in, &ain);

		if (ret < 0)

			return ret;

	} else {

		if (in->length > U32_MAX)

			return -E2BIG;



		ain.length = in->length;

		ain.pointer = in->data;

	}



	status = wmidev_evaluate_method(wdev, instance, method_id, &ain, NULL);



	if (wblock->gblock.flags & ACPI_WMI_STRING)

		kfree(ain.pointer);



	if (ACPI_FAILURE(status))

		return -EIO;



	return 0;

}

EXPORT_SYMBOL_GPL(wmidev_invoke_procedure);



static acpi_status __query_block(struct wmi_block *wblock, u8 instance,

				 struct acpi_buffer *out)

{

include/linux/wmi.h

+3 −0
Original line number Diff line number Diff line
@@ -70,6 +70,9 @@ ssize_t wmi_string_from_utf8s(struct wmi_string *str, size_t max_chars, const u8 
int wmidev_invoke_method(struct wmi_device *wdev, u8 instance, u32 method_id,

			 const struct wmi_buffer *in, struct wmi_buffer *out);



int wmidev_invoke_procedure(struct wmi_device *wdev, u8 instance, u32 method_id,

			    const struct wmi_buffer *in);



int wmidev_query_block(struct wmi_device *wdev, u8 instance, struct wmi_buffer *out);



int wmidev_set_block(struct wmi_device *wdev, u8 instance, const struct wmi_buffer *in);