diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 330 |
1 files changed, 220 insertions, 110 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 073045cb214e..67d39a90b45c 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -49,6 +49,9 @@ static LIST_HEAD(wait_for_suppliers); static DEFINE_MUTEX(wfs_lock); static LIST_HEAD(deferred_sync); static unsigned int defer_sync_state_count = 1; +static unsigned int defer_fw_devlink_count; +static DEFINE_MUTEX(defer_fw_devlink_lock); +static bool fw_devlink_is_permissive(void); #ifdef CONFIG_SRCU static DEFINE_MUTEX(device_links_lock); @@ -365,6 +368,7 @@ struct device_link *device_link_add(struct device *consumer, link->flags |= DL_FLAG_STATELESS; goto reorder; } else { + link->flags |= DL_FLAG_STATELESS; goto out; } } @@ -433,12 +437,16 @@ struct device_link *device_link_add(struct device *consumer, flags & DL_FLAG_PM_RUNTIME) pm_runtime_resume(supplier); + list_add_tail_rcu(&link->s_node, &supplier->links.consumers); + list_add_tail_rcu(&link->c_node, &consumer->links.suppliers); + if (flags & DL_FLAG_SYNC_STATE_ONLY) { dev_dbg(consumer, "Linked as a sync state only consumer to %s\n", dev_name(supplier)); goto out; } + reorder: /* * Move the consumer and all of the devices depending on it to the end @@ -449,12 +457,9 @@ reorder: */ device_reorder_to_tail(consumer, NULL); - list_add_tail_rcu(&link->s_node, &supplier->links.consumers); - list_add_tail_rcu(&link->c_node, &consumer->links.suppliers); - dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier)); - out: +out: device_pm_unlock(); device_links_write_unlock(); @@ -527,7 +532,7 @@ static void device_link_add_missing_supplier_links(void) int ret = fwnode_call_int_op(dev->fwnode, add_links, dev); if (!ret) list_del_init(&dev->links.needs_suppliers); - else if (ret != -ENODEV) + else if (ret != -ENODEV || fw_devlink_is_permissive()) dev->links.need_for_probe = false; } mutex_unlock(&wfs_lock); @@ -641,9 +646,17 @@ static void device_links_missing_supplier(struct device *dev) { struct device_link *link; - list_for_each_entry(link, &dev->links.suppliers, c_node) - if (link->status == DL_STATE_CONSUMER_PROBE) + list_for_each_entry(link, &dev->links.suppliers, c_node) { + if (link->status != DL_STATE_CONSUMER_PROBE) + continue; + + if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { WRITE_ONCE(link->status, DL_STATE_AVAILABLE); + } else { + WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); + WRITE_ONCE(link->status, DL_STATE_DORMANT); + } + } } /** @@ -682,11 +695,11 @@ int device_links_check_suppliers(struct device *dev) device_links_write_lock(); list_for_each_entry(link, &dev->links.suppliers, c_node) { - if (!(link->flags & DL_FLAG_MANAGED) || - link->flags & DL_FLAG_SYNC_STATE_ONLY) + if (!(link->flags & DL_FLAG_MANAGED)) continue; - if (link->status != DL_STATE_AVAILABLE) { + if (link->status != DL_STATE_AVAILABLE && + !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) { device_links_missing_supplier(dev); ret = -EPROBE_DEFER; break; @@ -829,6 +842,13 @@ static void __device_links_supplier_defer_sync(struct device *sup) list_add_tail(&sup->links.defer_sync, &deferred_sync); } +static void device_link_drop_managed(struct device_link *link) +{ + link->flags &= ~DL_FLAG_MANAGED; + WRITE_ONCE(link->status, DL_STATE_NONE); + kref_put(&link->kref, __device_link_del); +} + /** * device_links_driver_bound - Update device links after probing its driver. * @dev: Device to update the links for. @@ -842,7 +862,7 @@ static void __device_links_supplier_defer_sync(struct device *sup) */ void device_links_driver_bound(struct device *dev) { - struct device_link *link; + struct device_link *link, *ln; LIST_HEAD(sync_list); /* @@ -882,18 +902,35 @@ void device_links_driver_bound(struct device *dev) else __device_links_queue_sync_state(dev, &sync_list); - list_for_each_entry(link, &dev->links.suppliers, c_node) { + list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { + struct device *supplier; + if (!(link->flags & DL_FLAG_MANAGED)) continue; - WARN_ON(link->status != DL_STATE_CONSUMER_PROBE); - WRITE_ONCE(link->status, DL_STATE_ACTIVE); + supplier = link->supplier; + if (link->flags & DL_FLAG_SYNC_STATE_ONLY) { + /* + * When DL_FLAG_SYNC_STATE_ONLY is set, it means no + * other DL_MANAGED_LINK_FLAGS have been set. So, it's + * save to drop the managed link completely. + */ + device_link_drop_managed(link); + } else { + WARN_ON(link->status != DL_STATE_CONSUMER_PROBE); + WRITE_ONCE(link->status, DL_STATE_ACTIVE); + } + /* + * This needs to be done even for the deleted + * DL_FLAG_SYNC_STATE_ONLY device link in case it was the last + * device link that was preventing the supplier from getting a + * sync_state() call. + */ if (defer_sync_state_count) - __device_links_supplier_defer_sync(link->supplier); + __device_links_supplier_defer_sync(supplier); else - __device_links_queue_sync_state(link->supplier, - &sync_list); + __device_links_queue_sync_state(supplier, &sync_list); } dev->links.status = DL_DEV_DRIVER_BOUND; @@ -903,13 +940,6 @@ void device_links_driver_bound(struct device *dev) device_links_flush_sync_list(&sync_list, dev); } -static void device_link_drop_managed(struct device_link *link) -{ - link->flags &= ~DL_FLAG_MANAGED; - WRITE_ONCE(link->status, DL_STATE_NONE); - kref_put(&link->kref, __device_link_del); -} - /** * __device_links_no_driver - Update links of a device without a driver. * @dev: Device without a drvier. @@ -930,11 +960,21 @@ static void __device_links_no_driver(struct device *dev) if (!(link->flags & DL_FLAG_MANAGED)) continue; - if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) + if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) { device_link_drop_managed(link); - else if (link->status == DL_STATE_CONSUMER_PROBE || - link->status == DL_STATE_ACTIVE) + continue; + } + + if (link->status != DL_STATE_CONSUMER_PROBE && + link->status != DL_STATE_ACTIVE) + continue; + + if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { WRITE_ONCE(link->status, DL_STATE_AVAILABLE); + } else { + WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); + WRITE_ONCE(link->status, DL_STATE_DORMANT); + } } dev->links.status = DL_DEV_NO_DRIVER; @@ -1143,6 +1183,150 @@ static void device_links_purge(struct device *dev) device_links_write_unlock(); } +static u32 fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY; +static int __init fw_devlink_setup(char *arg) +{ + if (!arg) + return -EINVAL; + + if (strcmp(arg, "off") == 0) { + fw_devlink_flags = 0; + } else if (strcmp(arg, "permissive") == 0) { + fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY; + } else if (strcmp(arg, "on") == 0) { + fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER; + } else if (strcmp(arg, "rpm") == 0) { + fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER | + DL_FLAG_PM_RUNTIME; + } + return 0; +} +early_param("fw_devlink", fw_devlink_setup); + +u32 fw_devlink_get_flags(void) +{ + return fw_devlink_flags; +} + +static bool fw_devlink_is_permissive(void) +{ + return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY; +} + +static void fw_devlink_link_device(struct device *dev) +{ + int fw_ret; + + if (!fw_devlink_flags) + return; + + mutex_lock(&defer_fw_devlink_lock); + if (!defer_fw_devlink_count) + device_link_add_missing_supplier_links(); + + /* + * The device's fwnode not having add_links() doesn't affect if other + * consumers can find this device as a supplier. So, this check is + * intentionally placed after device_link_add_missing_supplier_links(). + */ + if (!fwnode_has_op(dev->fwnode, add_links)) + goto out; + + /* + * If fw_devlink is being deferred, assume all devices have mandatory + * suppliers they need to link to later. Then, when the fw_devlink is + * resumed, all these devices will get a chance to try and link to any + * suppliers they have. + */ + if (!defer_fw_devlink_count) { + fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev); + if (fw_ret == -ENODEV && fw_devlink_is_permissive()) + fw_ret = -EAGAIN; + } else { + fw_ret = -ENODEV; + } + + if (fw_ret == -ENODEV) + device_link_wait_for_mandatory_supplier(dev); + else if (fw_ret) + device_link_wait_for_optional_supplier(dev); + +out: + mutex_unlock(&defer_fw_devlink_lock); +} + +/** + * fw_devlink_pause - Pause parsing of fwnode to create device links + * + * Calling this function defers any fwnode parsing to create device links until + * fw_devlink_resume() is called. Both these functions are ref counted and the + * caller needs to match the calls. + * + * While fw_devlink is paused: + * - Any device that is added won't have its fwnode parsed to create device + * links. + * - The probe of the device will also be deferred during this period. + * - Any devices that were already added, but waiting for suppliers won't be + * able to link to newly added devices. + * + * Once fw_devlink_resume(): + * - All the fwnodes that was not parsed will be parsed. + * - All the devices that were deferred probing will be reattempted if they + * aren't waiting for any more suppliers. + * + * This pair of functions, is mainly meant to optimize the parsing of fwnodes + * when a lot of devices that need to link to each other are added in a short + * interval of time. For example, adding all the top level devices in a system. + * + * For example, if N devices are added and: + * - All the consumers are added before their suppliers + * - All the suppliers of the N devices are part of the N devices + * + * Then: + * + * - With the use of fw_devlink_pause() and fw_devlink_resume(), each device + * will only need one parsing of its fwnode because it is guaranteed to find + * all the supplier devices already registered and ready to link to. It won't + * have to do another pass later to find one or more suppliers it couldn't + * find in the first parse of the fwnode. So, we'll only need O(N) fwnode + * parses. + * + * - Without the use of fw_devlink_pause() and fw_devlink_resume(), we would + * end up doing O(N^2) parses of fwnodes because every device that's added is + * guaranteed to trigger a parse of the fwnode of every device added before + * it. This O(N^2) parse is made worse by the fact that when a fwnode of a + * device is parsed, all it descendant devices might need to have their + * fwnodes parsed too (even if the devices themselves aren't added). + */ +void fw_devlink_pause(void) +{ + mutex_lock(&defer_fw_devlink_lock); + defer_fw_devlink_count++; + mutex_unlock(&defer_fw_devlink_lock); +} + +/** fw_devlink_resume - Resume parsing of fwnode to create device links + * + * This function is used in conjunction with fw_devlink_pause() and is ref + * counted. See documentation for fw_devlink_pause() for more details. + */ +void fw_devlink_resume(void) +{ + mutex_lock(&defer_fw_devlink_lock); + if (!defer_fw_devlink_count) { + WARN(true, "Unmatched fw_devlink pause/resume!"); + goto out; + } + + defer_fw_devlink_count--; + if (defer_fw_devlink_count) + goto out; + + device_link_add_missing_supplier_links(); + driver_deferred_probe_force_trigger(); +out: + mutex_unlock(&defer_fw_devlink_lock); +} /* Device links support end. */ int (*platform_notify)(struct device *dev) = NULL; @@ -1374,7 +1558,7 @@ static void device_release(struct kobject *kobj) else if (dev->class && dev->class->dev_release) dev->class->dev_release(dev); else - WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n", + WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n", dev_name(dev)); kfree(p); } @@ -2345,36 +2529,6 @@ static int device_private_init(struct device *dev) return 0; } -static u32 fw_devlink_flags; -static int __init fw_devlink_setup(char *arg) -{ - if (!arg) - return -EINVAL; - - if (strcmp(arg, "off") == 0) { - fw_devlink_flags = 0; - } else if (strcmp(arg, "permissive") == 0) { - fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY; - } else if (strcmp(arg, "on") == 0) { - fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER; - } else if (strcmp(arg, "rpm") == 0) { - fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER | - DL_FLAG_PM_RUNTIME; - } - return 0; -} -early_param("fw_devlink", fw_devlink_setup); - -u32 fw_devlink_get_flags(void) -{ - return fw_devlink_flags; -} - -static bool fw_devlink_is_permissive(void) -{ - return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY; -} - /** * device_add - add device to device hierarchy. * @dev: device. @@ -2407,9 +2561,8 @@ int device_add(struct device *dev) struct device *parent; struct kobject *kobj; struct class_interface *class_intf; - int error = -EINVAL, fw_ret; + int error = -EINVAL; struct kobject *glue_dir = NULL; - bool is_fwnode_dev = false; dev = get_device(dev); if (!dev) @@ -2507,11 +2660,6 @@ int device_add(struct device *dev) kobject_uevent(&dev->kobj, KOBJ_ADD); - if (dev->fwnode && !dev->fwnode->dev) { - dev->fwnode->dev = dev; - is_fwnode_dev = true; - } - /* * Check if any of the other devices (consumers) have been waiting for * this device (supplier) to be added so that they can create a device @@ -2520,19 +2668,13 @@ int device_add(struct device *dev) * This needs to happen after device_pm_add() because device_link_add() * requires the supplier be registered before it's called. * - * But this also needs to happe before bus_probe_device() to make sure + * But this also needs to happen before bus_probe_device() to make sure * waiting consumers can link to it before the driver is bound to the * device and the driver sync_state callback is called for this device. */ - device_link_add_missing_supplier_links(); - - if (fw_devlink_flags && is_fwnode_dev && - fwnode_has_op(dev->fwnode, add_links)) { - fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev); - if (fw_ret == -ENODEV && !fw_devlink_is_permissive()) - device_link_wait_for_mandatory_supplier(dev); - else if (fw_ret) - device_link_wait_for_optional_supplier(dev); + if (dev->fwnode && !dev->fwnode->dev) { + dev->fwnode->dev = dev; + fw_devlink_link_device(dev); } bus_probe_device(dev); @@ -3194,40 +3336,6 @@ error: } /** - * device_create_vargs - creates a device and registers it with sysfs - * @class: pointer to the struct class that this device should be registered to - * @parent: pointer to the parent struct device of this new device, if any - * @devt: the dev_t for the char device to be added - * @drvdata: the data to be added to the device for callbacks - * @fmt: string for the device's name - * @args: va_list for the device's name - * - * This function can be used by char device classes. A struct device - * will be created in sysfs, registered to the specified class. - * - * A "dev" file will be created, showing the dev_t for the device, if - * the dev_t is not 0,0. - * If a pointer to a parent struct device is passed in, the newly created - * struct device will be a child of that device in sysfs. - * The pointer to the struct device will be returned from the call. - * Any further sysfs files that might be required can be created using this - * pointer. - * - * Returns &struct device pointer on success, or ERR_PTR() on error. - * - * Note: the struct class passed to this function must have previously - * been created with a call to class_create(). - */ -struct device *device_create_vargs(struct class *class, struct device *parent, - dev_t devt, void *drvdata, const char *fmt, - va_list args) -{ - return device_create_groups_vargs(class, parent, devt, drvdata, NULL, - fmt, args); -} -EXPORT_SYMBOL_GPL(device_create_vargs); - -/** * device_create - creates a device and registers it with sysfs * @class: pointer to the struct class that this device should be registered to * @parent: pointer to the parent struct device of this new device, if any @@ -3258,7 +3366,8 @@ struct device *device_create(struct class *class, struct device *parent, struct device *dev; va_start(vargs, fmt); - dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs); + dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL, + fmt, vargs); va_end(vargs); return dev; } @@ -3896,6 +4005,7 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) else dev->fwnode = fwnode; } +EXPORT_SYMBOL_GPL(set_secondary_fwnode); /** * device_set_of_node_from_dev - reuse device-tree node of another device |