diff options
Diffstat (limited to 'drivers/platform/x86/wmi.c')
| -rw-r--r-- | drivers/platform/x86/wmi.c | 1519 |
1 files changed, 1519 insertions, 0 deletions
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c new file mode 100644 index 000000000..b3f3e23a6 --- /dev/null +++ b/drivers/platform/x86/wmi.c @@ -0,0 +1,1519 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ACPI-WMI mapping driver + * + * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk> + * + * GUID parsing code from ldm.c is: + * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org> + * Copyright (c) 2001-2007 Anton Altaparmakov + * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com> + * + * WMI bus infrastructure by Andrew Lutomirski and Darren Hart: + * Copyright (C) 2015 Andrew Lutomirski + * Copyright (C) 2017 VMware, Inc. All Rights Reserved. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/acpi.h> +#include <linux/bits.h> +#include <linux/build_bug.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/uuid.h> +#include <linux/wmi.h> +#include <linux/fs.h> +#include <uapi/linux/wmi.h> + +MODULE_AUTHOR("Carlos Corbacho"); +MODULE_DESCRIPTION("ACPI-WMI Mapping Driver"); +MODULE_LICENSE("GPL"); + +static LIST_HEAD(wmi_block_list); + +struct guid_block { + guid_t guid; + union { + char object_id[2]; + struct { + unsigned char notify_id; + unsigned char reserved; + }; + }; + u8 instance_count; + u8 flags; +} __packed; +static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16); +static_assert(sizeof(struct guid_block) == 20); +static_assert(__alignof__(struct guid_block) == 1); + +enum { /* wmi_block flags */ + WMI_READ_TAKES_NO_ARGS, + WMI_PROBED, +}; + +struct wmi_block { + struct wmi_device dev; + struct list_head list; + struct guid_block gblock; + struct miscdevice char_dev; + struct mutex char_mutex; + struct acpi_device *acpi_device; + wmi_notify_handler handler; + void *handler_data; + u64 req_buf_size; + unsigned long flags; +}; + + +/* + * If the GUID data block is marked as expensive, we must enable and + * explicitily disable data collection. + */ +#define ACPI_WMI_EXPENSIVE BIT(0) +#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */ +#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */ +#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */ + +static bool debug_event; +module_param(debug_event, bool, 0444); +MODULE_PARM_DESC(debug_event, + "Log WMI Events [0/1]"); + +static bool debug_dump_wdg; +module_param(debug_dump_wdg, bool, 0444); +MODULE_PARM_DESC(debug_dump_wdg, + "Dump available WMI interfaces [0/1]"); + +static const struct acpi_device_id wmi_device_ids[] = { + {"PNP0C14", 0}, + {"pnp0c14", 0}, + { } +}; +MODULE_DEVICE_TABLE(acpi, wmi_device_ids); + +/* allow duplicate GUIDs as these device drivers use struct wmi_driver */ +static const char * const allow_duplicates[] = { + "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */ + NULL +}; + +/* + * GUID parsing functions + */ + +static acpi_status find_guid(const char *guid_string, struct wmi_block **out) +{ + guid_t guid_input; + struct wmi_block *wblock; + + if (!guid_string) + return AE_BAD_PARAMETER; + + if (guid_parse(guid_string, &guid_input)) + return AE_BAD_PARAMETER; + + list_for_each_entry(wblock, &wmi_block_list, list) { + if (guid_equal(&wblock->gblock.guid, &guid_input)) { + if (out) + *out = wblock; + + return AE_OK; + } + } + + 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) +{ + const struct wmi_device_id *id; + + id = wdriver->id_table; + if (!id) + return NULL; + + while (*id->guid_string) { + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) + return id->context; + id++; + } + return NULL; +} + +static int get_subobj_info(acpi_handle handle, const char *pathname, + struct acpi_device_info **info) +{ + struct acpi_device_info *dummy_info, **info_ptr; + acpi_handle subobj_handle; + acpi_status status; + + status = acpi_get_handle(handle, (char *)pathname, &subobj_handle); + if (status == AE_NOT_FOUND) + return -ENOENT; + else if (ACPI_FAILURE(status)) + return -EIO; + + info_ptr = info ? info : &dummy_info; + status = acpi_get_object_info(subobj_handle, info_ptr); + if (ACPI_FAILURE(status)) + return -EIO; + + if (!info) + kfree(dummy_info); + + return 0; +} + +static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable) +{ + struct guid_block *block; + char method[5]; + acpi_status status; + acpi_handle handle; + + block = &wblock->gblock; + handle = wblock->acpi_device->handle; + + snprintf(method, 5, "WE%02X", block->notify_id); + status = acpi_execute_simple_method(handle, method, enable); + if (status == AE_NOT_FOUND) + return AE_OK; + + return status; +} + +#define WMI_ACPI_METHOD_NAME_SIZE 5 + +static inline void get_acpi_method_name(const struct wmi_block *wblock, + const char method, + char buffer[static WMI_ACPI_METHOD_NAME_SIZE]) +{ + static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2); + static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5); + + buffer[0] = 'W'; + buffer[1] = method; + buffer[2] = wblock->gblock.object_id[0]; + buffer[3] = wblock->gblock.object_id[1]; + buffer[4] = '\0'; +} + +static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock) +{ + if (wblock->gblock.flags & ACPI_WMI_STRING) + return ACPI_TYPE_STRING; + else + return ACPI_TYPE_BUFFER; +} + +static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out) +{ + union acpi_object param = { + .integer = { + .type = ACPI_TYPE_INTEGER, + .value = wblock->gblock.notify_id, + } + }; + struct acpi_object_list input = { + .count = 1, + .pointer = ¶m, + }; + + return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out); +} + +/* + * Exported WMI functions + */ + +/** + * set_required_buffer_size - Sets the buffer size needed for performing IOCTL + * @wdev: A wmi bus device from a driver + * @length: Required buffer size + * + * Allocates memory needed for buffer, stores the buffer size in that memory + */ +int set_required_buffer_size(struct wmi_device *wdev, u64 length) +{ + struct wmi_block *wblock; + + wblock = container_of(wdev, struct wmi_block, dev); + wblock->req_buf_size = length; + + return 0; +} +EXPORT_SYMBOL_GPL(set_required_buffer_size); + +/** + * wmi_evaluate_method - Evaluate a WMI method + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba + * @instance: Instance index + * @method_id: Method ID to call + * @in: Buffer containing input for the method call + * @out: Empty buffer to return the method results + * + * Call an ACPI-WMI method + */ +acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id, + const struct acpi_buffer *in, struct acpi_buffer *out) +{ + struct wmi_block *wblock = NULL; + acpi_status status; + + status = find_guid(guid_string, &wblock); + if (ACPI_FAILURE(status)) + return status; + + return wmidev_evaluate_method(&wblock->dev, instance, method_id, + in, out); +} +EXPORT_SYMBOL_GPL(wmi_evaluate_method); + +/** + * wmidev_evaluate_method - Evaluate a WMI method + * @wdev: A wmi bus device from a driver + * @instance: Instance index + * @method_id: Method ID to call + * @in: Buffer containing input for the method call + * @out: Empty buffer to return the method results + * + * Call an ACPI-WMI method + */ +acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id, + const struct acpi_buffer *in, struct acpi_buffer *out) +{ + struct guid_block *block; + struct wmi_block *wblock; + acpi_handle handle; + struct acpi_object_list input; + union acpi_object params[3]; + char method[WMI_ACPI_METHOD_NAME_SIZE]; + + wblock = container_of(wdev, struct wmi_block, dev); + block = &wblock->gblock; + handle = wblock->acpi_device->handle; + + if (!(block->flags & ACPI_WMI_METHOD)) + return AE_BAD_DATA; + + if (block->instance_count <= instance) + return AE_BAD_PARAMETER; + + input.count = 2; + input.pointer = params; + params[0].type = ACPI_TYPE_INTEGER; + params[0].integer.value = instance; + params[1].type = ACPI_TYPE_INTEGER; + params[1].integer.value = method_id; + + if (in) { + input.count = 3; + + params[2].type = get_param_acpi_type(wblock); + params[2].buffer.length = in->length; + params[2].buffer.pointer = in->pointer; + } + + get_acpi_method_name(wblock, 'M', method); + + return acpi_evaluate_object(handle, method, &input, out); +} +EXPORT_SYMBOL_GPL(wmidev_evaluate_method); + +static acpi_status __query_block(struct wmi_block *wblock, u8 instance, + struct acpi_buffer *out) +{ + struct guid_block *block; + acpi_handle handle; + acpi_status status, wc_status = AE_ERROR; + struct acpi_object_list input; + union acpi_object wq_params[1]; + char wc_method[WMI_ACPI_METHOD_NAME_SIZE]; + char method[WMI_ACPI_METHOD_NAME_SIZE]; + + if (!out) + return AE_BAD_PARAMETER; + + block = &wblock->gblock; + handle = wblock->acpi_device->handle; + + if (block->instance_count <= instance) + return AE_BAD_PARAMETER; + + /* Check GUID is a data block */ + if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) + return AE_ERROR; + + input.count = 1; + input.pointer = wq_params; + wq_params[0].type = ACPI_TYPE_INTEGER; + wq_params[0].integer.value = instance; + + if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags)) + input.count = 0; + + /* + * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to + * enable collection. + */ + if (block->flags & ACPI_WMI_EXPENSIVE) { + get_acpi_method_name(wblock, 'C', wc_method); + + /* + * Some GUIDs break the specification by declaring themselves + * expensive, but have no corresponding WCxx method. So we + * should not fail if this happens. + */ + wc_status = acpi_execute_simple_method(handle, wc_method, 1); + } + + get_acpi_method_name(wblock, 'Q', method); + status = acpi_evaluate_object(handle, method, &input, out); + + /* + * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if + * the WQxx method failed - we should disable collection anyway. + */ + if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) { + /* + * Ignore whether this WCxx call succeeds or not since + * the previously executed WQxx method call might have + * succeeded, and returning the failing status code + * of this call would throw away the result of the WQxx + * call, potentially leaking memory. + */ + acpi_execute_simple_method(handle, wc_method, 0); + } + + return status; +} + +/** + * wmi_query_block - Return contents of a WMI block (deprecated) + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba + * @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 + */ +acpi_status wmi_query_block(const char *guid_string, u8 instance, + struct acpi_buffer *out) +{ + struct wmi_block *wblock; + acpi_status status; + + status = find_guid(guid_string, &wblock); + if (ACPI_FAILURE(status)) + return status; + + return __query_block(wblock, instance, out); +} +EXPORT_SYMBOL_GPL(wmi_query_block); + +union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) +{ + struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; + struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); + + if (ACPI_FAILURE(__query_block(wblock, instance, &out))) + return NULL; + + return out.pointer; +} +EXPORT_SYMBOL_GPL(wmidev_block_query); + +/** + * wmi_set_block - Write to a WMI block + * @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 + * + * Write the contents of the input buffer to an ACPI-WMI data block + */ +acpi_status wmi_set_block(const char *guid_string, u8 instance, + const struct acpi_buffer *in) +{ + struct wmi_block *wblock = NULL; + struct guid_block *block; + acpi_handle handle; + struct acpi_object_list input; + union acpi_object params[2]; + char method[WMI_ACPI_METHOD_NAME_SIZE]; + acpi_status status; + + if (!in) + return AE_BAD_DATA; + + status = find_guid(guid_string, &wblock); + if (ACPI_FAILURE(status)) + return status; + + block = &wblock->gblock; + handle = wblock->acpi_device->handle; + + if (block->instance_count <= instance) + return AE_BAD_PARAMETER; + + /* Check GUID is a data block */ + if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) + return AE_ERROR; + + input.count = 2; + input.pointer = params; + params[0].type = ACPI_TYPE_INTEGER; + params[0].integer.value = instance; + params[1].type = get_param_acpi_type(wblock); + params[1].buffer.length = in->length; + params[1].buffer.pointer = in->pointer; + + get_acpi_method_name(wblock, 'S', method); + + return acpi_evaluate_object(handle, method, &input, NULL); +} +EXPORT_SYMBOL_GPL(wmi_set_block); + +static void wmi_dump_wdg(const struct guid_block *g) +{ + pr_info("%pUL:\n", &g->guid); + if (g->flags & ACPI_WMI_EVENT) + pr_info("\tnotify_id: 0x%02X\n", g->notify_id); + else + pr_info("\tobject_id: %2pE\n", g->object_id); + pr_info("\tinstance_count: %d\n", g->instance_count); + pr_info("\tflags: %#x", g->flags); + if (g->flags) { + if (g->flags & ACPI_WMI_EXPENSIVE) + pr_cont(" ACPI_WMI_EXPENSIVE"); + if (g->flags & ACPI_WMI_METHOD) + pr_cont(" ACPI_WMI_METHOD"); + if (g->flags & ACPI_WMI_STRING) + pr_cont(" ACPI_WMI_STRING"); + if (g->flags & ACPI_WMI_EVENT) + pr_cont(" ACPI_WMI_EVENT"); + } + pr_cont("\n"); + +} + +static void wmi_notify_debug(u32 value, void *context) +{ + struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + acpi_status status; + + status = wmi_get_event_data(value, &response); + if (status != AE_OK) { + pr_info("bad event status 0x%x\n", status); + return; + } + + obj = response.pointer; + if (!obj) + return; + + pr_info("DEBUG: event 0x%02X ", value); + switch (obj->type) { + case ACPI_TYPE_BUFFER: + pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length); + break; + case ACPI_TYPE_STRING: + pr_cont("STRING_TYPE - %s\n", obj->string.pointer); + break; + case ACPI_TYPE_INTEGER: + pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value); + break; + case ACPI_TYPE_PACKAGE: + pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count); + break; + default: + pr_cont("object type 0x%X\n", obj->type); + } + kfree(obj); +} + +/** + * wmi_install_notify_handler - Register handler for WMI events + * @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 + * + * Register a handler for events sent to the ACPI-WMI mapper device. + */ +acpi_status wmi_install_notify_handler(const char *guid, + wmi_notify_handler handler, + void *data) +{ + struct wmi_block *block; + acpi_status status = AE_NOT_EXIST; + guid_t guid_input; + + if (!guid || !handler) + return AE_BAD_PARAMETER; + + if (guid_parse(guid, &guid_input)) + return AE_BAD_PARAMETER; + + list_for_each_entry(block, &wmi_block_list, list) { + acpi_status wmi_status; + + if (guid_equal(&block->gblock.guid, &guid_input)) { + if (block->handler && + block->handler != wmi_notify_debug) + return AE_ALREADY_ACQUIRED; + + block->handler = handler; + block->handler_data = data; + + wmi_status = wmi_method_enable(block, true); + if ((wmi_status != AE_OK) || + ((wmi_status == AE_OK) && (status == AE_NOT_EXIST))) + status = wmi_status; + } + } + + return status; +} +EXPORT_SYMBOL_GPL(wmi_install_notify_handler); + +/** + * wmi_remove_notify_handler - Unregister handler for WMI events + * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba + * + * Unregister handler for events sent to the ACPI-WMI mapper device. + */ +acpi_status wmi_remove_notify_handler(const char *guid) +{ + struct wmi_block *block; + acpi_status status = AE_NOT_EXIST; + guid_t guid_input; + + if (!guid) + return AE_BAD_PARAMETER; + + if (guid_parse(guid, &guid_input)) + return AE_BAD_PARAMETER; + + list_for_each_entry(block, &wmi_block_list, list) { + acpi_status wmi_status; + + if (guid_equal(&block->gblock.guid, &guid_input)) { + if (!block->handler || + block->handler == wmi_notify_debug) + return AE_NULL_ENTRY; + + if (debug_event) { + block->handler = wmi_notify_debug; + status = AE_OK; + } else { + wmi_status = wmi_method_enable(block, false); + block->handler = NULL; + block->handler_data = NULL; + if ((wmi_status != AE_OK) || + ((wmi_status == AE_OK) && + (status == AE_NOT_EXIST))) + status = wmi_status; + } + } + } + + return status; +} +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() + * + * Returns extra data associated with an event in WMI. + */ +acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) +{ + struct wmi_block *wblock; + + list_for_each_entry(wblock, &wmi_block_list, list) { + struct guid_block *gblock = &wblock->gblock; + + if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event) + return get_event_data(wblock, out); + } + + return AE_NOT_FOUND; +} +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 + */ +bool wmi_has_guid(const char *guid_string) +{ + return ACPI_SUCCESS(find_guid(guid_string, NULL)); +} +EXPORT_SYMBOL_GPL(wmi_has_guid); + +/** + * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba + * + * 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 + */ +char *wmi_get_acpi_device_uid(const char *guid_string) +{ + struct wmi_block *wblock = NULL; + acpi_status status; + + status = find_guid(guid_string, &wblock); + if (ACPI_FAILURE(status)) + return NULL; + + return acpi_device_uid(wblock->acpi_device); +} +EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid); + +static struct wmi_block *dev_to_wblock(struct device *dev) +{ + return container_of(dev, struct wmi_block, dev.dev); +} + +static struct wmi_device *dev_to_wdev(struct device *dev) +{ + return container_of(dev, struct wmi_device, dev); +} + +static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv) +{ + return container_of(drv, struct wmi_driver, driver); +} + +/* + * sysfs interface + */ +static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid); +} +static DEVICE_ATTR_RO(modalias); + +static ssize_t guid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid); +} +static DEVICE_ATTR_RO(guid); + +static ssize_t instance_count_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count); +} +static DEVICE_ATTR_RO(instance_count); + +static ssize_t expensive_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "%d\n", + (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0); +} +static DEVICE_ATTR_RO(expensive); + +static struct attribute *wmi_attrs[] = { + &dev_attr_modalias.attr, + &dev_attr_guid.attr, + &dev_attr_instance_count.attr, + &dev_attr_expensive.attr, + NULL +}; +ATTRIBUTE_GROUPS(wmi); + +static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id); +} +static DEVICE_ATTR_RO(notify_id); + +static struct attribute *wmi_event_attrs[] = { + &dev_attr_notify_id.attr, + NULL +}; +ATTRIBUTE_GROUPS(wmi_event); + +static ssize_t object_id_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0], + wblock->gblock.object_id[1]); +} +static DEVICE_ATTR_RO(object_id); + +static ssize_t setable_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct wmi_device *wdev = dev_to_wdev(dev); + + return sysfs_emit(buf, "%d\n", (int)wdev->setable); +} +static DEVICE_ATTR_RO(setable); + +static struct attribute *wmi_data_attrs[] = { + &dev_attr_object_id.attr, + &dev_attr_setable.attr, + NULL +}; +ATTRIBUTE_GROUPS(wmi_data); + +static struct attribute *wmi_method_attrs[] = { + &dev_attr_object_id.attr, + NULL +}; +ATTRIBUTE_GROUPS(wmi_method); + +static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid)) + return -ENOMEM; + + if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid)) + return -ENOMEM; + + return 0; +} + +static void wmi_dev_release(struct device *dev) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + + kfree(wblock); +} + +static int wmi_dev_match(struct device *dev, struct device_driver *driver) +{ + struct wmi_driver *wmi_driver = drv_to_wdrv(driver); + struct wmi_block *wblock = dev_to_wblock(dev); + const struct wmi_device_id *id = wmi_driver->id_table; + + if (id == NULL) + return 0; + + while (*id->guid_string) { + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) + return 1; + + id++; + } + + return 0; +} +static int wmi_char_open(struct inode *inode, struct file *filp) +{ + /* + * The miscdevice already stores a pointer to itself + * inside filp->private_data + */ + struct wmi_block *wblock = container_of(filp->private_data, struct wmi_block, char_dev); + + filp->private_data = wblock; + + return nonseekable_open(inode, filp); +} + +static ssize_t wmi_char_read(struct file *filp, char __user *buffer, + size_t length, loff_t *offset) +{ + struct wmi_block *wblock = filp->private_data; + + return simple_read_from_buffer(buffer, length, offset, + &wblock->req_buf_size, + sizeof(wblock->req_buf_size)); +} + +static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct wmi_ioctl_buffer __user *input = + (struct wmi_ioctl_buffer __user *) arg; + struct wmi_block *wblock = filp->private_data; + struct wmi_ioctl_buffer *buf; + struct wmi_driver *wdriver; + int ret; + + if (_IOC_TYPE(cmd) != WMI_IOC) + return -ENOTTY; + + /* make sure we're not calling a higher instance than exists*/ + if (_IOC_NR(cmd) >= wblock->gblock.instance_count) + return -EINVAL; + + mutex_lock(&wblock->char_mutex); + buf = wblock->handler_data; + if (get_user(buf->length, &input->length)) { + dev_dbg(&wblock->dev.dev, "Read length from user failed\n"); + ret = -EFAULT; + goto out_ioctl; + } + /* if it's too small, abort */ + if (buf->length < wblock->req_buf_size) { + dev_err(&wblock->dev.dev, + "Buffer %lld too small, need at least %lld\n", + buf->length, wblock->req_buf_size); + ret = -EINVAL; + goto out_ioctl; + } + /* if it's too big, warn, driver will only use what is needed */ + if (buf->length > wblock->req_buf_size) + dev_warn(&wblock->dev.dev, + "Buffer %lld is bigger than required %lld\n", + buf->length, wblock->req_buf_size); + + /* copy the structure from userspace */ + if (copy_from_user(buf, input, wblock->req_buf_size)) { + dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n", + wblock->req_buf_size); + ret = -EFAULT; + goto out_ioctl; + } + + /* let the driver do any filtering and do the call */ + wdriver = drv_to_wdrv(wblock->dev.dev.driver); + if (!try_module_get(wdriver->driver.owner)) { + ret = -EBUSY; + goto out_ioctl; + } + ret = wdriver->filter_callback(&wblock->dev, cmd, buf); + module_put(wdriver->driver.owner); + if (ret) + goto out_ioctl; + + /* return the result (only up to our internal buffer size) */ + if (copy_to_user(input, buf, wblock->req_buf_size)) { + dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n", + wblock->req_buf_size); + ret = -EFAULT; + } + +out_ioctl: + mutex_unlock(&wblock->char_mutex); + return ret; +} + +static const struct file_operations wmi_fops = { + .owner = THIS_MODULE, + .read = wmi_char_read, + .open = wmi_char_open, + .unlocked_ioctl = wmi_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +static int wmi_dev_probe(struct device *dev) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + struct wmi_driver *wdriver = drv_to_wdrv(dev->driver); + int ret = 0; + char *buf; + + if (ACPI_FAILURE(wmi_method_enable(wblock, true))) + dev_warn(dev, "failed to enable device -- probing anyway\n"); + + if (wdriver->probe) { + ret = wdriver->probe(dev_to_wdev(dev), + find_guid_context(wblock, wdriver)); + if (ret != 0) + goto probe_failure; + } + + /* driver wants a character device made */ + if (wdriver->filter_callback) { + /* check that required buffer size declared by driver or MOF */ + if (!wblock->req_buf_size) { + dev_err(&wblock->dev.dev, + "Required buffer size not set\n"); + ret = -EINVAL; + goto probe_failure; + } + + wblock->handler_data = kmalloc(wblock->req_buf_size, + GFP_KERNEL); + if (!wblock->handler_data) { + ret = -ENOMEM; + goto probe_failure; + } + + buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name); + if (!buf) { + ret = -ENOMEM; + goto probe_string_failure; + } + wblock->char_dev.minor = MISC_DYNAMIC_MINOR; + wblock->char_dev.name = buf; + wblock->char_dev.fops = &wmi_fops; + wblock->char_dev.mode = 0444; + ret = misc_register(&wblock->char_dev); + if (ret) { + dev_warn(dev, "failed to register char dev: %d\n", ret); + ret = -ENOMEM; + goto probe_misc_failure; + } + } + + set_bit(WMI_PROBED, &wblock->flags); + return 0; + +probe_misc_failure: + kfree(buf); +probe_string_failure: + kfree(wblock->handler_data); +probe_failure: + if (ACPI_FAILURE(wmi_method_enable(wblock, false))) + dev_warn(dev, "failed to disable device\n"); + return ret; +} + +static void wmi_dev_remove(struct device *dev) +{ + struct wmi_block *wblock = dev_to_wblock(dev); + struct wmi_driver *wdriver = drv_to_wdrv(dev->driver); + + clear_bit(WMI_PROBED, &wblock->flags); + + if (wdriver->filter_callback) { + misc_deregister(&wblock->char_dev); + kfree(wblock->char_dev.name); + kfree(wblock->handler_data); + } + + if (wdriver->remove) + wdriver->remove(dev_to_wdev(dev)); + + if (ACPI_FAILURE(wmi_method_enable(wblock, false))) + dev_warn(dev, "failed to disable device\n"); +} + +static struct class wmi_bus_class = { + .name = "wmi_bus", +}; + +static struct bus_type wmi_bus_type = { + .name = "wmi", + .dev_groups = wmi_groups, + .match = wmi_dev_match, + .uevent = wmi_dev_uevent, + .probe = wmi_dev_probe, + .remove = wmi_dev_remove, +}; + +static const struct device_type wmi_type_event = { + .name = "event", + .groups = wmi_event_groups, + .release = wmi_dev_release, +}; + +static const struct device_type wmi_type_method = { + .name = "method", + .groups = wmi_method_groups, + .release = wmi_dev_release, +}; + +static const struct device_type wmi_type_data = { + .name = "data", + .groups = wmi_data_groups, + .release = wmi_dev_release, +}; + +/* + * _WDG is a static list that is only parsed at startup, + * so it's safe to count entries without extra protection. + */ +static int guid_count(const guid_t *guid) +{ + struct wmi_block *wblock; + int count = 0; + + list_for_each_entry(wblock, &wmi_block_list, list) { + if (guid_equal(&wblock->gblock.guid, guid)) + count++; + } + + return count; +} + +static int wmi_create_device(struct device *wmi_bus_dev, + struct wmi_block *wblock, + struct acpi_device *device) +{ + struct acpi_device_info *info; + char method[WMI_ACPI_METHOD_NAME_SIZE]; + int result; + uint count; + + if (wblock->gblock.flags & ACPI_WMI_EVENT) { + wblock->dev.dev.type = &wmi_type_event; + goto out_init; + } + + if (wblock->gblock.flags & ACPI_WMI_METHOD) { + wblock->dev.dev.type = &wmi_type_method; + mutex_init(&wblock->char_mutex); + goto out_init; + } + + /* + * Data Block Query Control Method (WQxx by convention) is + * required per the WMI documentation. If it is not present, + * we ignore this data block. + */ + get_acpi_method_name(wblock, 'Q', method); + result = get_subobj_info(device->handle, method, &info); + + if (result) { + dev_warn(wmi_bus_dev, + "%s data block query control method not found\n", + method); + return result; + } + + wblock->dev.dev.type = &wmi_type_data; + + /* + * The Microsoft documentation specifically states: + * + * Data blocks registered with only a single instance + * can ignore the parameter. + * + * ACPICA will get mad at us if we call the method with the wrong number + * of arguments, so check what our method expects. (On some Dell + * laptops, WQxx may not be a method at all.) + */ + if (info->type != ACPI_TYPE_METHOD || info->param_count == 0) + set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags); + + kfree(info); + + get_acpi_method_name(wblock, 'S', method); + result = get_subobj_info(device->handle, method, NULL); + + if (result == 0) + wblock->dev.setable = true; + + out_init: + wblock->dev.dev.bus = &wmi_bus_type; + wblock->dev.dev.parent = wmi_bus_dev; + + count = guid_count(&wblock->gblock.guid); + if (count) + dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count); + else + dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid); + + device_initialize(&wblock->dev.dev); + + return 0; +} + +static void wmi_free_devices(struct acpi_device *device) +{ + struct wmi_block *wblock, *next; + + /* Delete devices for all the GUIDs */ + list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { + if (wblock->acpi_device == device) { + list_del(&wblock->list); + device_unregister(&wblock->dev.dev); + } + } +} + +static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid) +{ + struct wmi_block *wblock; + + 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)) + return false; + } + if (guid_equal(&wblock->gblock.guid, guid)) { + /* + * Because we historically didn't track the relationship + * between GUIDs and ACPI nodes, we don't know whether + * we need to suppress GUIDs that are unique on a + * given node but duplicated across nodes. + */ + dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n", + guid, dev_name(&wblock->acpi_device->dev)); + return true; + } + } + + return false; +} + +/* + * Parse the _WDG method for the GUID data blocks + */ +static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device) +{ + struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; + const struct guid_block *gblock; + struct wmi_block *wblock, *next; + union acpi_object *obj; + acpi_status status; + u32 i, total; + int retval; + + status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out); + if (ACPI_FAILURE(status)) + return -ENXIO; + + obj = out.pointer; + if (!obj) + return -ENXIO; + + if (obj->type != ACPI_TYPE_BUFFER) { + kfree(obj); + return -ENXIO; + } + + gblock = (const struct guid_block *)obj->buffer.pointer; + total = obj->buffer.length / sizeof(struct guid_block); + + for (i = 0; i < total; i++) { + if (debug_dump_wdg) + wmi_dump_wdg(&gblock[i]); + + if (!gblock[i].instance_count) { + dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid); + continue; + } + + if (guid_already_parsed_for_legacy(device, &gblock[i].guid)) + continue; + + wblock = kzalloc(sizeof(*wblock), GFP_KERNEL); + if (!wblock) { + dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid); + continue; + } + + wblock->acpi_device = device; + wblock->gblock = gblock[i]; + + retval = wmi_create_device(wmi_bus_dev, wblock, device); + if (retval) { + kfree(wblock); + continue; + } + + list_add_tail(&wblock->list, &wmi_block_list); + + if (debug_event) { + wblock->handler = wmi_notify_debug; + wmi_method_enable(wblock, true); + } + } + + /* + * Now that all of the devices are created, add them to the + * device tree and probe subdrivers. + */ + list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { + if (wblock->acpi_device != device) + continue; + + retval = device_add(&wblock->dev.dev); + if (retval) { + dev_err(wmi_bus_dev, "failed to register %pUL\n", + &wblock->gblock.guid); + if (debug_event) + wmi_method_enable(wblock, false); + list_del(&wblock->list); + put_device(&wblock->dev.dev); + } + } + + kfree(obj); + + return 0; +} + +/* + * WMI can have EmbeddedControl access regions. In which case, we just want to + * hand these off to the EC driver. + */ +static acpi_status +acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address, + u32 bits, u64 *value, + void *handler_context, void *region_context) +{ + int result = 0, i = 0; + u8 temp = 0; + + if ((address > 0xFF) || !value) + return AE_BAD_PARAMETER; + + if (function != ACPI_READ && function != ACPI_WRITE) + return AE_BAD_PARAMETER; + + if (bits != 8) + return AE_BAD_PARAMETER; + + if (function == ACPI_READ) { + result = ec_read(address, &temp); + (*value) |= ((u64)temp) << i; + } else { + temp = 0xff & ((*value) >> i); + result = ec_write(address, temp); + } + + switch (result) { + case -EINVAL: + return AE_BAD_PARAMETER; + case -ENODEV: + return AE_NOT_FOUND; + case -ETIME: + return AE_TIME; + default: + return AE_OK; + } +} + +static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, + void *context) +{ + struct wmi_block *wblock = NULL, *iter; + + list_for_each_entry(iter, &wmi_block_list, list) { + struct guid_block *block = &iter->gblock; + + if (iter->acpi_device->handle == handle && + (block->flags & ACPI_WMI_EVENT) && + (block->notify_id == event)) { + wblock = iter; + break; + } + } + + if (!wblock) + return; + + /* If a driver is bound, then notify the driver. */ + if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) { + struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver); + struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL }; + acpi_status status; + + if (!driver->no_notify_data) { + status = get_event_data(wblock, &evdata); + if (ACPI_FAILURE(status)) { + dev_warn(&wblock->dev.dev, "failed to get event data\n"); + return; + } + } + + if (driver->notify) + driver->notify(&wblock->dev, evdata.pointer); + + kfree(evdata.pointer); + } else if (wblock->handler) { + /* Legacy handler */ + wblock->handler(event, wblock->handler_data); + } + + if (debug_event) + pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event); + + acpi_bus_generate_netlink_event( + wblock->acpi_device->pnp.device_class, + dev_name(&wblock->dev.dev), + event, 0); +} + +static int acpi_wmi_remove(struct platform_device *device) +{ + struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev); + + acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, + acpi_wmi_notify_handler); + acpi_remove_address_space_handler(acpi_device->handle, + ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); + wmi_free_devices(acpi_device); + device_unregister(dev_get_drvdata(&device->dev)); + + return 0; +} + +static int acpi_wmi_probe(struct platform_device *device) +{ + struct acpi_device *acpi_device; + struct device *wmi_bus_dev; + acpi_status status; + int error; + + acpi_device = ACPI_COMPANION(&device->dev); + if (!acpi_device) { + dev_err(&device->dev, "ACPI companion is missing\n"); + return -ENODEV; + } + + status = acpi_install_address_space_handler(acpi_device->handle, + ACPI_ADR_SPACE_EC, + &acpi_wmi_ec_space_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) { + dev_err(&device->dev, "Error installing EC region handler\n"); + return -ENODEV; + } + + status = acpi_install_notify_handler(acpi_device->handle, + ACPI_ALL_NOTIFY, + acpi_wmi_notify_handler, + NULL); + if (ACPI_FAILURE(status)) { + dev_err(&device->dev, "Error installing notify handler\n"); + error = -ENODEV; + goto err_remove_ec_handler; + } + + wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), + NULL, "wmi_bus-%s", dev_name(&device->dev)); + if (IS_ERR(wmi_bus_dev)) { + error = PTR_ERR(wmi_bus_dev); + goto err_remove_notify_handler; + } + dev_set_drvdata(&device->dev, wmi_bus_dev); + + error = parse_wdg(wmi_bus_dev, acpi_device); + if (error) { + pr_err("Failed to parse WDG method\n"); + goto err_remove_busdev; + } + + return 0; + +err_remove_busdev: + device_unregister(wmi_bus_dev); + +err_remove_notify_handler: + acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, + acpi_wmi_notify_handler); + +err_remove_ec_handler: + acpi_remove_address_space_handler(acpi_device->handle, + ACPI_ADR_SPACE_EC, + &acpi_wmi_ec_space_handler); + + return error; +} + +int __must_check __wmi_driver_register(struct wmi_driver *driver, + struct module *owner) +{ + driver->driver.owner = owner; + driver->driver.bus = &wmi_bus_type; + + return driver_register(&driver->driver); +} +EXPORT_SYMBOL(__wmi_driver_register); + +void wmi_driver_unregister(struct wmi_driver *driver) +{ + driver_unregister(&driver->driver); +} +EXPORT_SYMBOL(wmi_driver_unregister); + +static struct platform_driver acpi_wmi_driver = { + .driver = { + .name = "acpi-wmi", + .acpi_match_table = wmi_device_ids, + }, + .probe = acpi_wmi_probe, + .remove = acpi_wmi_remove, +}; + +static int __init acpi_wmi_init(void) +{ + int error; + + if (acpi_disabled) + return -ENODEV; + + error = class_register(&wmi_bus_class); + if (error) + return error; + + error = bus_register(&wmi_bus_type); + if (error) + goto err_unreg_class; + + error = platform_driver_register(&acpi_wmi_driver); + if (error) { + pr_err("Error loading mapper\n"); + goto err_unreg_bus; + } + + return 0; + +err_unreg_bus: + bus_unregister(&wmi_bus_type); + +err_unreg_class: + class_unregister(&wmi_bus_class); + + return error; +} + +static void __exit acpi_wmi_exit(void) +{ + platform_driver_unregister(&acpi_wmi_driver); + bus_unregister(&wmi_bus_type); + class_unregister(&wmi_bus_class); +} + +subsys_initcall_sync(acpi_wmi_init); +module_exit(acpi_wmi_exit); |