From b4cc979588ee94b179e28c6f3f5c2d6197ea6461 Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Tue, 25 Apr 2023 00:29:36 +0200 Subject: platform/x86: wmi: Add kernel doc comments Add kernel doc comments useful for documenting the functions/structs used to interact with the WMI driver core. Signed-off-by: Armin Wolf Tested-by: Randy Dunlap Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20230424222939.208137-2-W_Armin@gmx.de Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 51 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 42 insertions(+), 9 deletions(-) (limited to 'drivers/platform/x86/wmi.c') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index d81319a502ef..99af2cc03b0f 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -248,7 +248,9 @@ static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_bu * @wdev: A wmi bus device from a driver * @length: Required buffer size * - * Allocates memory needed for buffer, stores the buffer size in that memory + * Allocates memory needed for buffer, stores the buffer size in that memory. + * + * Return: 0 on success or a negative error code for failure. */ int set_required_buffer_size(struct wmi_device *wdev, u64 length) { @@ -269,7 +271,9 @@ EXPORT_SYMBOL_GPL(set_required_buffer_size); * @in: Buffer containing input for the method call * @out: Empty buffer to return the method results * - * Call an ACPI-WMI method + * Call an ACPI-WMI method, the caller must free @out. + * + * Return: acpi_status signaling success or error. */ acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) @@ -294,7 +298,9 @@ EXPORT_SYMBOL_GPL(wmi_evaluate_method); * @in: Buffer containing input for the method call * @out: Empty buffer to return the method results * - * Call an ACPI-WMI method + * Call an ACPI-WMI method, the caller must free @out. + * + * Return: acpi_status signaling success or error. */ acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) @@ -411,7 +417,9 @@ static acpi_status __query_block(struct wmi_block *wblock, u8 instance, * @instance: Instance index * @out: Empty buffer to return the contents of the data block to * - * Return the contents of an ACPI-WMI data block to a buffer + * Query a ACPI-WMI block, the caller must free @out. + * + * Return: ACPI object containing the content of the WMI block. */ acpi_status wmi_query_block(const char *guid_string, u8 instance, struct acpi_buffer *out) @@ -427,6 +435,15 @@ acpi_status wmi_query_block(const char *guid_string, u8 instance, } EXPORT_SYMBOL_GPL(wmi_query_block); +/** + * wmidev_block_query - Return contents of a WMI block + * @wdev: A wmi bus device from a driver + * @instance: Instance index + * + * Query an ACPI-WMI block, the caller must free the result. + * + * Return: ACPI object containing the content of the WMI block. + */ union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) { struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; @@ -445,7 +462,9 @@ EXPORT_SYMBOL_GPL(wmidev_block_query); * @instance: Instance index * @in: Buffer containing new values for the data block * - * Write the contents of the input buffer to an ACPI-WMI data block + * Write the contents of the input buffer to an ACPI-WMI data block. + * + * Return: acpi_status signaling success or error. */ acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in) @@ -555,6 +574,8 @@ static void wmi_notify_debug(u32 value, void *context) * @data: Data to be returned to handler when event is fired * * Register a handler for events sent to the ACPI-WMI mapper device. + * + * Return: acpi_status signaling success or error. */ acpi_status wmi_install_notify_handler(const char *guid, wmi_notify_handler handler, @@ -597,6 +618,8 @@ EXPORT_SYMBOL_GPL(wmi_install_notify_handler); * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Unregister handler for events sent to the ACPI-WMI mapper device. + * + * Return: acpi_status signaling success or error. */ acpi_status wmi_remove_notify_handler(const char *guid) { @@ -641,9 +664,11 @@ EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); * wmi_get_event_data - Get WMI data associated with an event * * @event: Event to find - * @out: Buffer to hold event data. out->pointer should be freed with kfree() + * @out: Buffer to hold event data + * + * Get extra data associated with an WMI event, the caller needs to free @out. * - * Returns extra data associated with an event in WMI. + * Return: acpi_status signaling success or error. */ acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) { @@ -664,7 +689,9 @@ EXPORT_SYMBOL_GPL(wmi_get_event_data); * wmi_has_guid - Check if a GUID is available * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * - * Check if a given GUID is defined by _WDG + * Check if a given GUID is defined by _WDG. + * + * Return: True if GUID is available, false otherwise. */ bool wmi_has_guid(const char *guid_string) { @@ -678,7 +705,7 @@ EXPORT_SYMBOL_GPL(wmi_has_guid); * * Find the _UID of ACPI device associated with this WMI GUID. * - * Return: The ACPI _UID field value or NULL if the WMI GUID was not found + * Return: The ACPI _UID field value or NULL if the WMI GUID was not found. */ char *wmi_get_acpi_device_uid(const char *guid_string) { @@ -1454,6 +1481,12 @@ int __must_check __wmi_driver_register(struct wmi_driver *driver, } EXPORT_SYMBOL(__wmi_driver_register); +/** + * wmi_driver_unregister() - Unregister a WMI driver + * @driver: WMI driver to unregister + * + * Unregisters a WMI driver from the WMI bus. + */ void wmi_driver_unregister(struct wmi_driver *driver) { driver_unregister(&driver->driver); -- cgit From d54bd4bc7b9ae9505f53440894b8c239c521f3da Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Tue, 25 Apr 2023 00:29:37 +0200 Subject: platform/x86: wmi: Mark GUID-based WMI interface as deprecated The WMI driver core supports a more mordern bus-based interface for interacting with WMI devices. The older GUID-based interface depends on each WMI GUID and notification id being unique on a given system, which turned out is not the case. Mark the older interface as deprecated since new WMI drivers should use the bus-based interface to avoid this issues. Signed-off-by: Armin Wolf Tested-by: Randy Dunlap Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20230424222939.208137-3-W_Armin@gmx.de Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/platform/x86/wmi.c') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 99af2cc03b0f..c226dd4163a1 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -264,7 +264,7 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length) EXPORT_SYMBOL_GPL(set_required_buffer_size); /** - * wmi_evaluate_method - Evaluate a WMI method + * wmi_evaluate_method - Evaluate a WMI method (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @method_id: Method ID to call @@ -457,7 +457,7 @@ union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) EXPORT_SYMBOL_GPL(wmidev_block_query); /** - * wmi_set_block - Write to a WMI block + * wmi_set_block - Write to a WMI block (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @in: Buffer containing new values for the data block @@ -568,7 +568,7 @@ static void wmi_notify_debug(u32 value, void *context) } /** - * wmi_install_notify_handler - Register handler for WMI events + * wmi_install_notify_handler - Register handler for WMI events (deprecated) * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @handler: Function to handle notifications * @data: Data to be returned to handler when event is fired @@ -614,7 +614,7 @@ acpi_status wmi_install_notify_handler(const char *guid, EXPORT_SYMBOL_GPL(wmi_install_notify_handler); /** - * wmi_remove_notify_handler - Unregister handler for WMI events + * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated) * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Unregister handler for events sent to the ACPI-WMI mapper device. @@ -661,7 +661,7 @@ acpi_status wmi_remove_notify_handler(const char *guid) EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); /** - * wmi_get_event_data - Get WMI data associated with an event + * wmi_get_event_data - Get WMI data associated with an event (deprecated) * * @event: Event to find * @out: Buffer to hold event data @@ -700,7 +700,7 @@ bool wmi_has_guid(const char *guid_string) EXPORT_SYMBOL_GPL(wmi_has_guid); /** - * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID + * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Find the _UID of ACPI device associated with this WMI GUID. -- cgit From 2a2b13ae50cf70e07b471301ff50299f31d81c1d Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Sun, 30 Apr 2023 22:31:52 +0200 Subject: platform/x86: wmi: Allow retrieving the number of WMI object instances 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 Link: https://lore.kernel.org/r/20230430203153.5587-2-W_Armin@gmx.de Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 41 +++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 2 ++ include/linux/wmi.h | 2 ++ 3 files changed, 45 insertions(+) (limited to 'drivers/platform/x86/wmi.c') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index c226dd4163a1..5b95d7aa5c2f 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -263,6 +263,47 @@ 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 + * + * Get the number of WMI object instances. + * + * Returns: Number of WMI object instances or negative error code. + */ +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)) { + if (status == AE_BAD_PARAMETER) + return -EINVAL; + + return -ENODEV; + } + + return wmidev_instance_count(&wblock->dev); +} +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 7b71dd74baeb..5b9353f56928 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -414,6 +414,8 @@ extern bool acpi_is_pnp_device(struct acpi_device *); typedef void (*wmi_notify_handler) (u32 value, void *context); +int wmi_instance_count(const char *guid); + 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); /** -- cgit From 028e6e204ace1f080cfeacd72c50397eb8ae8883 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 21 Jun 2023 18:11:54 +0300 Subject: platform/x86: wmi: Break possible infinite loop when parsing GUID The while-loop may break on one of the two conditions, either ID string is empty or GUID matches. The second one, may never be reached if the parsed string is not correct GUID. In such a case the loop will never advance to check the next ID. Break possible infinite loop by factoring out guid_parse_and_compare() helper which may be moved to the generic header for everyone later on and preventing from similar mistake in the future. Interestingly that firstly it appeared when WMI was turned into a bus driver, but later when duplicated GUIDs were checked, the while-loop has been replaced by for-loop and hence no mistake made again. Fixes: a48e23385fcf ("platform/x86: wmi: add context pointer field to struct wmi_device_id") Fixes: 844af950da94 ("platform/x86: wmi: Turn WMI into a bus driver") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230621151155.78279-1-andriy.shevchenko@linux.intel.com Tested-by: Armin Wolf Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'drivers/platform/x86/wmi.c') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 5b95d7aa5c2f..098512a53170 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -136,6 +136,16 @@ static acpi_status find_guid(const char *guid_string, struct wmi_block **out) return AE_NOT_FOUND; } +static bool guid_parse_and_compare(const char *string, const guid_t *guid) +{ + guid_t guid_input; + + if (guid_parse(string, &guid_input)) + return false; + + return guid_equal(&guid_input, guid); +} + static const void *find_guid_context(struct wmi_block *wblock, struct wmi_driver *wdriver) { @@ -146,11 +156,7 @@ static const void *find_guid_context(struct wmi_block *wblock, return NULL; while (*id->guid_string) { - guid_t guid_input; - - if (guid_parse(id->guid_string, &guid_input)) - continue; - if (guid_equal(&wblock->gblock.guid, &guid_input)) + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return id->context; id++; } @@ -895,11 +901,7 @@ static int wmi_dev_match(struct device *dev, struct device_driver *driver) return 0; while (*id->guid_string) { - guid_t driver_guid; - - if (WARN_ON(guid_parse(id->guid_string, &driver_guid))) - continue; - if (guid_equal(&driver_guid, &wblock->gblock.guid)) + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return 1; id++; -- cgit From 6bf06f14bf33d668ee0eb85b6c414d85a0f8e1a5 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 21 Jun 2023 18:11:55 +0300 Subject: platform/x86: wmi: Replace open coded guid_parse_and_compare() Even though we have no issues in the code, let's replace the open coded guid_parse_and_compare(). Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230621151155.78279-2-andriy.shevchenko@linux.intel.com Tested-by: Armin Wolf Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/platform/x86/wmi.c') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 098512a53170..a78ddd83cda0 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -1241,11 +1241,7 @@ static bool guid_already_parsed_for_legacy(struct acpi_device *device, const gui list_for_each_entry(wblock, &wmi_block_list, list) { /* skip warning and register if we know the driver will use struct wmi_driver */ for (int i = 0; allow_duplicates[i] != NULL; i++) { - guid_t tmp; - - if (guid_parse(allow_duplicates[i], &tmp)) - continue; - if (guid_equal(&tmp, guid)) + if (guid_parse_and_compare(allow_duplicates[i], guid)) return false; } if (guid_equal(&wblock->gblock.guid, guid)) { -- cgit