// SPDX-License-Identifier: GPL-2.0-or-later /* * ACPI-WMI mapping driver * * Copyright (C) 2007-2008 Carlos Corbacho * * GUID parsing code from ldm.c is: * Copyright (C) 2001,2002 Richard Russon * Copyright (c) 2001-2007 Anton Altaparmakov * Copyright (C) 2001,2002 Jakob Kemi * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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) { const char *driver_name = filp->f_path.dentry->d_iname; struct wmi_block *wblock; struct wmi_block *next; list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { if (!wblock->dev.dev.driver) continue; if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) { filp->private_data = wblock; break; } } if (!filp->private_data) return -ENODEV; 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; int retval = 0; u32 i, total; 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) { retval = -ENXIO; goto out_free_pointer; } 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 (guid_already_parsed_for_legacy(device, &gblock[i].guid)) continue; wblock = kzalloc(sizeof(*wblock), GFP_KERNEL); if (!wblock) { retval = -ENOMEM; break; } 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); } } out_free_pointer: kfree(out.pointer); return retval; } /* * 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);