diff options
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-deferred_probe | 12 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/intel_cacheinfo.c | 2 | ||||
-rw-r--r-- | drivers/base/Kconfig | 2 | ||||
-rw-r--r-- | drivers/base/Makefile | 2 | ||||
-rw-r--r-- | drivers/base/base.h | 15 | ||||
-rw-r--r-- | drivers/base/cacheinfo.c | 138 | ||||
-rw-r--r-- | drivers/base/class.c | 15 | ||||
-rw-r--r-- | drivers/base/core.c | 578 | ||||
-rw-r--r-- | drivers/base/dd.c | 79 | ||||
-rw-r--r-- | drivers/base/devcoredump.c | 10 | ||||
-rw-r--r-- | drivers/base/dma-mapping.c | 4 | ||||
-rw-r--r-- | drivers/base/firmware_class.c | 178 | ||||
-rw-r--r-- | drivers/base/memory.c | 2 | ||||
-rw-r--r-- | drivers/base/power/main.c | 87 | ||||
-rw-r--r-- | drivers/base/power/power.h | 10 | ||||
-rw-r--r-- | drivers/base/power/runtime.c | 174 | ||||
-rw-r--r-- | drivers/base/test/Kconfig | 9 | ||||
-rw-r--r-- | drivers/base/test/Makefile | 1 | ||||
-rw-r--r-- | drivers/base/test/test_async_driver_probe.c | 169 | ||||
-rw-r--r-- | fs/kernfs/inode.c | 4 | ||||
-rw-r--r-- | include/linux/cacheinfo.h | 1 | ||||
-rw-r--r-- | include/linux/debugfs.h | 44 | ||||
-rw-r--r-- | include/linux/device.h | 91 | ||||
-rw-r--r-- | include/linux/pm.h | 2 | ||||
-rw-r--r-- | include/linux/pm_runtime.h | 10 | ||||
-rw-r--r-- | lib/kobject_uevent.c | 6 |
26 files changed, 1517 insertions, 128 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-deferred_probe b/Documentation/ABI/testing/sysfs-devices-deferred_probe new file mode 100644 index 0000000..58553d7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-deferred_probe @@ -0,0 +1,12 @@ +What: /sys/devices/.../deferred_probe +Date: August 2016 +Contact: Ben Hutchings <ben.hutchings@codethink.co.uk> +Description: + The /sys/devices/.../deferred_probe attribute is + present for all devices. If a driver detects during + probing a device that a related device is not yet + ready, it may defer probing of the first device. The + kernel will retry probing the first device after any + other device is successfully probed. This attribute + reads as 1 if probing of this device is currently + deferred, or 0 otherwise. diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c index de6626c..be63371 100644 --- a/arch/x86/kernel/cpu/intel_cacheinfo.c +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c @@ -934,6 +934,8 @@ static int __populate_cache_leaves(unsigned int cpu) ci_leaf_init(this_leaf++, &id4_regs); __cache_cpumap_setup(cpu, idx, &id4_regs); } + this_cpu_ci->cpu_map_populated = true; + return 0; } diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index afa67f9..d718ae4 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -224,6 +224,8 @@ config DEBUG_TEST_DRIVER_REMOVE unusable. You should say N here unless you are explicitly looking to test this functionality. +source "drivers/base/test/Kconfig" + config SYS_HYPERVISOR bool default n diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 2609ba2..f2816f6 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -24,5 +24,7 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o +obj-y += test/ + ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/base.h b/drivers/base/base.h index e05db38..ada9dce 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -107,6 +107,9 @@ extern void bus_remove_device(struct device *dev); extern int bus_add_driver(struct device_driver *drv); extern void bus_remove_driver(struct device_driver *drv); +extern void device_release_driver_internal(struct device *dev, + struct device_driver *drv, + struct device *parent); extern void driver_detach(struct device_driver *drv); extern int driver_probe_device(struct device_driver *drv, struct device *dev); @@ -138,6 +141,8 @@ extern void device_unblock_probing(void); extern struct kset *devices_kset; extern void devices_kset_move_last(struct device *dev); +extern struct device_attribute dev_attr_deferred_probe; + #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS) extern void module_add_driver(struct module *mod, struct device_driver *drv); extern void module_remove_driver(struct device_driver *drv); @@ -152,3 +157,13 @@ extern int devtmpfs_init(void); #else static inline int devtmpfs_init(void) { return 0; } #endif + +/* Device links support */ +extern int device_links_read_lock(void); +extern void device_links_read_unlock(int idx); +extern int device_links_check_suppliers(struct device *dev); +extern void device_links_driver_bound(struct device *dev); +extern void device_links_driver_cleanup(struct device *dev); +extern void device_links_no_driver(struct device *dev); +extern bool device_links_busy(struct device *dev); +extern void device_links_unbind_consumers(struct device *dev); diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 47983a2..1e3903d 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -16,6 +16,9 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/acpi.h> #include <linux/bitops.h> #include <linux/cacheinfo.h> #include <linux/compiler.h> @@ -85,7 +88,120 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, { return sib_leaf->of_node == this_leaf->of_node; } + +/* OF properties to query for a given cache type */ +struct cache_type_info { + const char *size_prop; + const char *line_size_props[2]; + const char *nr_sets_prop; +}; + +static const struct cache_type_info cache_type_info[] = { + { + .size_prop = "cache-size", + .line_size_props = { "cache-line-size", + "cache-block-size", }, + .nr_sets_prop = "cache-sets", + }, { + .size_prop = "i-cache-size", + .line_size_props = { "i-cache-line-size", + "i-cache-block-size", }, + .nr_sets_prop = "i-cache-sets", + }, { + .size_prop = "d-cache-size", + .line_size_props = { "d-cache-line-size", + "d-cache-block-size", }, + .nr_sets_prop = "d-cache-sets", + }, +}; + +static inline int get_cacheinfo_idx(enum cache_type type) +{ + if (type == CACHE_TYPE_UNIFIED) + return 0; + return type; +} + +static void cache_size(struct cacheinfo *this_leaf) +{ + const char *propname; + const __be32 *cache_size; + int ct_idx; + + ct_idx = get_cacheinfo_idx(this_leaf->type); + propname = cache_type_info[ct_idx].size_prop; + + cache_size = of_get_property(this_leaf->of_node, propname, NULL); + if (cache_size) + this_leaf->size = of_read_number(cache_size, 1); +} + +/* not cache_line_size() because that's a macro in include/linux/cache.h */ +static void cache_get_line_size(struct cacheinfo *this_leaf) +{ + const __be32 *line_size; + int i, lim, ct_idx; + + ct_idx = get_cacheinfo_idx(this_leaf->type); + lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props); + + for (i = 0; i < lim; i++) { + const char *propname; + + propname = cache_type_info[ct_idx].line_size_props[i]; + line_size = of_get_property(this_leaf->of_node, propname, NULL); + if (line_size) + break; + } + + if (line_size) + this_leaf->coherency_line_size = of_read_number(line_size, 1); +} + +static void cache_nr_sets(struct cacheinfo *this_leaf) +{ + const char *propname; + const __be32 *nr_sets; + int ct_idx; + + ct_idx = get_cacheinfo_idx(this_leaf->type); + propname = cache_type_info[ct_idx].nr_sets_prop; + + nr_sets = of_get_property(this_leaf->of_node, propname, NULL); + if (nr_sets) + this_leaf->number_of_sets = of_read_number(nr_sets, 1); +} + +static void cache_associativity(struct cacheinfo *this_leaf) +{ + unsigned int line_size = this_leaf->coherency_line_size; + unsigned int nr_sets = this_leaf->number_of_sets; + unsigned int size = this_leaf->size; + + /* + * If the cache is fully associative, there is no need to + * check the other properties. + */ + if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0)) + this_leaf->ways_of_associativity = (size / nr_sets) / line_size; +} + +static void cache_of_override_properties(unsigned int cpu) +{ + int index; + struct cacheinfo *this_leaf; + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + + for (index = 0; index < cache_leaves(cpu); index++) { + this_leaf = this_cpu_ci->info_list + index; + cache_size(this_leaf); + cache_get_line_size(this_leaf); + cache_nr_sets(this_leaf); + cache_associativity(this_leaf); + } +} #else +static void cache_of_override_properties(unsigned int cpu) { } static inline int cache_setup_of_node(unsigned int cpu) { return 0; } static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, struct cacheinfo *sib_leaf) @@ -104,9 +220,16 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); struct cacheinfo *this_leaf, *sib_leaf; unsigned int index; - int ret; + int ret = 0; - ret = cache_setup_of_node(cpu); + if (this_cpu_ci->cpu_map_populated) + return 0; + + if (of_have_populated_dt()) + ret = cache_setup_of_node(cpu); + else if (!acpi_disabled) + /* No cache property/hierarchy support yet in ACPI */ + ret = -ENOTSUPP; if (ret) return ret; @@ -161,6 +284,12 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) } } +static void cache_override_properties(unsigned int cpu) +{ + if (of_have_populated_dt()) + return cache_of_override_properties(cpu); +} + static void free_cache_attributes(unsigned int cpu) { if (!per_cpu_cacheinfo(cpu)) @@ -203,10 +332,11 @@ static int detect_cache_attributes(unsigned int cpu) */ ret = cache_shared_cpu_map_setup(cpu); if (ret) { - pr_warn("Unable to detect cache hierarchy from DT for CPU %d\n", - cpu); + pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu); goto free_ci; } + + cache_override_properties(cpu); return 0; free_ci: diff --git a/drivers/base/class.c b/drivers/base/class.c index 71059e3..a2b2896 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -163,6 +163,18 @@ static void klist_class_dev_put(struct klist_node *n) put_device(dev); } +static int class_add_groups(struct class *cls, + const struct attribute_group **groups) +{ + return sysfs_create_groups(&cls->p->subsys.kobj, groups); +} + +static void class_remove_groups(struct class *cls, + const struct attribute_group **groups) +{ + return sysfs_remove_groups(&cls->p->subsys.kobj, groups); +} + int __class_register(struct class *cls, struct lock_class_key *key) { struct subsys_private *cp; @@ -203,6 +215,8 @@ int __class_register(struct class *cls, struct lock_class_key *key) kfree(cp); return error; } + error = class_add_groups(class_get(cls), cls->class_groups); + class_put(cls); error = add_class_attrs(class_get(cls)); class_put(cls); return error; @@ -213,6 +227,7 @@ void class_unregister(struct class *cls) { pr_debug("device class '%s': unregistering\n", cls->name); remove_class_attrs(cls); + class_remove_groups(cls, cls->class_groups); kset_unregister(&cls->p->subsys); } diff --git a/drivers/base/core.c b/drivers/base/core.c index ce057a5..020ea7f 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -44,6 +44,572 @@ static int __init sysfs_deprecated_setup(char *arg) early_param("sysfs.deprecated", sysfs_deprecated_setup); #endif +/* Device links support. */ + +#ifdef CONFIG_SRCU +static DEFINE_MUTEX(device_links_lock); +DEFINE_STATIC_SRCU(device_links_srcu); + +static inline void device_links_write_lock(void) +{ + mutex_lock(&device_links_lock); +} + +static inline void device_links_write_unlock(void) +{ + mutex_unlock(&device_links_lock); +} + +int device_links_read_lock(void) +{ + return srcu_read_lock(&device_links_srcu); +} + +void device_links_read_unlock(int idx) +{ + srcu_read_unlock(&device_links_srcu, idx); +} +#else /* !CONFIG_SRCU */ +static DECLARE_RWSEM(device_links_lock); + +static inline void device_links_write_lock(void) +{ + down_write(&device_links_lock); +} + +static inline void device_links_write_unlock(void) +{ + up_write(&device_links_lock); +} + +int device_links_read_lock(void) +{ + down_read(&device_links_lock); + return 0; +} + +void device_links_read_unlock(int not_used) +{ + up_read(&device_links_lock); +} +#endif /* !CONFIG_SRCU */ + +/** + * device_is_dependent - Check if one device depends on another one + * @dev: Device to check dependencies for. + * @target: Device to check against. + * + * Check if @target depends on @dev or any device dependent on it (its child or + * its consumer etc). Return 1 if that is the case or 0 otherwise. + */ +static int device_is_dependent(struct device *dev, void *target) +{ + struct device_link *link; + int ret; + + if (WARN_ON(dev == target)) + return 1; + + ret = device_for_each_child(dev, target, device_is_dependent); + if (ret) + return ret; + + list_for_each_entry(link, &dev->links.consumers, s_node) { + if (WARN_ON(link->consumer == target)) + return 1; + + ret = device_is_dependent(link->consumer, target); + if (ret) + break; + } + return ret; +} + +static int device_reorder_to_tail(struct device *dev, void *not_used) +{ + struct device_link *link; + + /* + * Devices that have not been registered yet will be put to the ends + * of the lists during the registration, so skip them here. + */ + if (device_is_registered(dev)) + devices_kset_move_last(dev); + + if (device_pm_initialized(dev)) + device_pm_move_last(dev); + + device_for_each_child(dev, NULL, device_reorder_to_tail); + list_for_each_entry(link, &dev->links.consumers, s_node) + device_reorder_to_tail(link->consumer, NULL); + + return 0; +} + +/** + * device_link_add - Create a link between two devices. + * @consumer: Consumer end of the link. + * @supplier: Supplier end of the link. + * @flags: Link flags. + * + * The caller is responsible for the proper synchronization of the link creation + * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the + * runtime PM framework to take the link into account. Second, if the + * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will + * be forced into the active metastate and reference-counted upon the creation + * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be + * ignored. + * + * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically + * when the consumer device driver unbinds from it. The combination of both + * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL + * to be returned. + * + * A side effect of the link creation is re-ordering of dpm_list and the + * devices_kset list by moving the consumer device and all devices depending + * on it to the ends of these lists (that does not happen to devices that have + * not been registered when this function is called). + * + * The supplier device is required to be registered when this function is called + * and NULL will be returned if that is not the case. The consumer device need + * not be registered, however. + */ +struct device_link *device_link_add(struct device *consumer, + struct device *supplier, u32 flags) +{ + struct device_link *link; + + if (!consumer || !supplier || + ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE))) + return NULL; + + device_links_write_lock(); + device_pm_lock(); + + /* + * If the supplier has not been fully registered yet or there is a + * reverse dependency between the consumer and the supplier already in + * the graph, return NULL. + */ + if (!device_pm_initialized(supplier) + || device_is_dependent(consumer, supplier)) { + link = NULL; + goto out; + } + + list_for_each_entry(link, &supplier->links.consumers, s_node) + if (link->consumer == consumer) + goto out; + + link = kzalloc(sizeof(*link), GFP_KERNEL); + if (!link) + goto out; + + if (flags & DL_FLAG_PM_RUNTIME) { + if (flags & DL_FLAG_RPM_ACTIVE) { + if (pm_runtime_get_sync(supplier) < 0) { + pm_runtime_put_noidle(supplier); + kfree(link); + link = NULL; + goto out; + } + link->rpm_active = true; + } + pm_runtime_new_link(consumer); + } + get_device(supplier); + link->supplier = supplier; + INIT_LIST_HEAD(&link->s_node); + get_device(consumer); + link->consumer = consumer; + INIT_LIST_HEAD(&link->c_node); + link->flags = flags; + + /* Determine the initial link state. */ + if (flags & DL_FLAG_STATELESS) { + link->status = DL_STATE_NONE; + } else { + switch (supplier->links.status) { + case DL_DEV_DRIVER_BOUND: + switch (consumer->links.status) { + case DL_DEV_PROBING: + /* + * Balance the decrementation of the supplier's + * runtime PM usage counter after consumer probe + * in driver_probe_device(). + */ + if (flags & DL_FLAG_PM_RUNTIME) + pm_runtime_get_sync(supplier); + + link->status = DL_STATE_CONSUMER_PROBE; + break; + case DL_DEV_DRIVER_BOUND: + link->status = DL_STATE_ACTIVE; + break; + default: + link->status = DL_STATE_AVAILABLE; + break; + } + break; + case DL_DEV_UNBINDING: + link->status = DL_STATE_SUPPLIER_UNBIND; + break; + default: + link->status = DL_STATE_DORMANT; + break; + } + } + + /* + * Move the consumer and all of the devices depending on it to the end + * of dpm_list and the devices_kset list. + * + * It is necessary to hold dpm_list locked throughout all that or else + * we may end up suspending with a wrong ordering of it. + */ + 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_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier)); + + out: + device_pm_unlock(); + device_links_write_unlock(); + return link; +} +EXPORT_SYMBOL_GPL(device_link_add); + +static void device_link_free(struct device_link *link) +{ + put_device(link->consumer); + put_device(link->supplier); + kfree(link); +} + +#ifdef CONFIG_SRCU +static void __device_link_free_srcu(struct rcu_head *rhead) +{ + device_link_free(container_of(rhead, struct device_link, rcu_head)); +} + +static void __device_link_del(struct device_link *link) +{ + dev_info(link->consumer, "Dropping the link to %s\n", + dev_name(link->supplier)); + + if (link->flags & DL_FLAG_PM_RUNTIME) + pm_runtime_drop_link(link->consumer); + + list_del_rcu(&link->s_node); + list_del_rcu(&link->c_node); + call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu); +} +#else /* !CONFIG_SRCU */ +static void __device_link_del(struct device_link *link) +{ + dev_info(link->consumer, "Dropping the link to %s\n", + dev_name(link->supplier)); + + list_del(&link->s_node); + list_del(&link->c_node); + device_link_free(link); +} +#endif /* !CONFIG_SRCU */ + +/** + * device_link_del - Delete a link between two devices. + * @link: Device link to delete. + * + * The caller must ensure proper synchronization of this function with runtime + * PM. + */ +void device_link_del(struct device_link *link) +{ + device_links_write_lock(); + device_pm_lock(); + __device_link_del(link); + device_pm_unlock(); + device_links_write_unlock(); +} +EXPORT_SYMBOL_GPL(device_link_del); + +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) + WRITE_ONCE(link->status, DL_STATE_AVAILABLE); +} + +/** + * device_links_check_suppliers - Check presence of supplier drivers. + * @dev: Consumer device. + * + * Check links from this device to any suppliers. Walk the list of the device's + * links to suppliers and see if all of them are available. If not, simply + * return -EPROBE_DEFER. + * + * We need to guarantee that the supplier will not go away after the check has + * been positive here. It only can go away in __device_release_driver() and + * that function checks the device's links to consumers. This means we need to + * mark the link as "consumer probe in progress" to make the supplier removal + * wait for us to complete (or bad things may happen). + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +int device_links_check_suppliers(struct device *dev) +{ + struct device_link *link; + int ret = 0; + + device_links_write_lock(); + + list_for_each_entry(link, &dev->links.suppliers, c_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + if (link->status != DL_STATE_AVAILABLE) { + device_links_missing_supplier(dev); + ret = -EPROBE_DEFER; + break; + } + WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); + } + dev->links.status = DL_DEV_PROBING; + + device_links_write_unlock(); + return ret; +} + +/** + * device_links_driver_bound - Update device links after probing its driver. + * @dev: Device to update the links for. + * + * The probe has been successful, so update links from this device to any + * consumers by changing their status to "available". + * + * Also change the status of @dev's links to suppliers to "active". + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +void device_links_driver_bound(struct device *dev) +{ + struct device_link *link; + + device_links_write_lock(); + + list_for_each_entry(link, &dev->links.consumers, s_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + WARN_ON(link->status != DL_STATE_DORMANT); + WRITE_ONCE(link->status, DL_STATE_AVAILABLE); + } + + list_for_each_entry(link, &dev->links.suppliers, c_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + WARN_ON(link->status != DL_STATE_CONSUMER_PROBE); + WRITE_ONCE(link->status, DL_STATE_ACTIVE); + } + + dev->links.status = DL_DEV_DRIVER_BOUND; + + device_links_write_unlock(); +} + +/** + * __device_links_no_driver - Update links of a device without a driver. + * @dev: Device without a drvier. + * + * Delete all non-persistent links from this device to any suppliers. + * + * Persistent links stay around, but their status is changed to "available", + * unless they already are in the "supplier unbind in progress" state in which + * case they need not be updated. + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +static void __device_links_no_driver(struct device *dev) +{ + struct device_link *link, *ln; + + list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + if (link->flags & DL_FLAG_AUTOREMOVE) + __device_link_del(link); + else if (link->status != DL_STATE_SUPPLIER_UNBIND) + WRITE_ONCE(link->status, DL_STATE_AVAILABLE); + } + + dev->links.status = DL_DEV_NO_DRIVER; +} + +void device_links_no_driver(struct device *dev) +{ + device_links_write_lock(); + __device_links_no_driver(dev); + device_links_write_unlock(); +} + +/** + * device_links_driver_cleanup - Update links after driver removal. + * @dev: Device whose driver has just gone away. + * + * Update links to consumers for @dev by changing their status to "dormant" and + * invoke %__device_links_no_driver() to update links to suppliers for it as + * appropriate. + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +void device_links_driver_cleanup(struct device *dev) +{ + struct device_link *link; + + device_links_write_lock(); + + list_for_each_entry(link, &dev->links.consumers, s_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + WARN_ON(link->flags & DL_FLAG_AUTOREMOVE); + WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND); + WRITE_ONCE(link->status, DL_STATE_DORMANT); + } + + __device_links_no_driver(dev); + + device_links_write_unlock(); +} + +/** + * device_links_busy - Check if there are any busy links to consumers. + * @dev: Device to check. + * + * Check each consumer of the device and return 'true' if its link's status + * is one of "consumer probe" or "active" (meaning that the given consumer is + * probing right now or its driver is present). Otherwise, change the link + * state to "supplier unbind" to prevent the consumer from being probed + * successfully going forward. + * + * Return 'false' if there are no probing or active consumers. + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +bool device_links_busy(struct device *dev) +{ + struct device_link *link; + bool ret = false; + + device_links_write_lock(); + + list_for_each_entry(link, &dev->links.consumers, s_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + if (link->status == DL_STATE_CONSUMER_PROBE + || link->status == DL_STATE_ACTIVE) { + ret = true; + break; + } + WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND); + } + + dev->links.status = DL_DEV_UNBINDING; + + device_links_write_unlock(); + return ret; +} + +/** + * device_links_unbind_consumers - Force unbind consumers of the given device. + * @dev: Device to unbind the consumers of. + * + * Walk the list of links to consumers for @dev and if any of them is in the + * "consumer probe" state, wait for all device probes in progress to complete + * and start over. + * + * If that's not the case, change the status of the link to "supplier unbind" + * and check if the link was in the "active" state. If so, force the consumer + * driver to unbind and start over (the consumer will not re-probe as we have + * changed the state of the link already). + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + */ +void device_links_unbind_consumers(struct device *dev) +{ + struct device_link *link; + + start: + device_links_write_lock(); + + list_for_each_entry(link, &dev->links.consumers, s_node) { + enum device_link_state status; + + if (link->flags & DL_FLAG_STATELESS) + continue; + + status = link->status; + if (status == DL_STATE_CONSUMER_PROBE) { + device_links_write_unlock(); + + wait_for_device_probe(); + goto start; + } + WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND); + if (status == DL_STATE_ACTIVE) { + struct device *consumer = link->consumer; + + get_device(consumer); + + device_links_write_unlock(); + + device_release_driver_internal(consumer, NULL, + consumer->parent); + put_device(consumer); + goto start; + } + } + + device_links_write_unlock(); +} + +/** + * device_links_purge - Delete existing links to other devices. + * @dev: Target device. + */ +static void device_links_purge(struct device *dev) +{ + struct device_link *link, *ln; + + /* + * Delete all of the remaining links from this device to any other + * devices (either consumers or suppliers). + */ + device_links_write_lock(); + + list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { + WARN_ON(link->status == DL_STATE_ACTIVE); + __device_link_del(link); + } + + list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) { + WARN_ON(link->status != DL_STATE_DORMANT && + link->status != DL_STATE_NONE); + __device_link_del(link); + } + + device_links_write_unlock(); +} + +/* Device links support end. */ + int (*platform_notify)(struct device *dev) = NULL; int (*platform_notify_remove)(struct device *dev) = NULL; static struct kobject *dev_kobj; @@ -494,8 +1060,14 @@ static int device_add_attrs(struct device *dev) goto err_remove_dev_groups; } + error = device_create_file(dev, &dev_attr_deferred_probe); + if (error) + goto err_remove_online; + return 0; + err_remove_online: + device_remove_file(dev, &dev_attr_online); err_remove_dev_groups: device_remove_groups(dev, dev->groups); err_remove_type_groups: @@ -513,6 +1085,7 @@ static void device_remove_attrs(struct device *dev) struct class *class = dev->class; const struct device_type *type = dev->type; + device_remove_file(dev, &dev_attr_deferred_probe); device_remove_file(dev, &dev_attr_online); device_remove_groups(dev, dev->groups); @@ -711,6 +1284,9 @@ void device_initialize(struct device *dev) #ifdef CONFIG_GENERIC_MSI_IRQ INIT_LIST_HEAD(&dev->msi_list); #endif + INIT_LIST_HEAD(&dev->links.consumers); + INIT_LIST_HEAD(&dev->links.suppliers); + dev->links.status = DL_DEV_NO_DRIVER; } EXPORT_SYMBOL_GPL(device_initialize); @@ -1258,6 +1834,8 @@ void device_del(struct device *dev) if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DEL_DEVICE, dev); + + device_links_purge(dev); dpm_sysfs_remove(dev); if (parent) klist_del(&dev->p->knode_parent); diff --git a/drivers/base/dd.c b/drivers/base/dd.c index d76cd97..a8b258e 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -53,6 +53,19 @@ static LIST_HEAD(deferred_probe_pending_list); static LIST_HEAD(deferred_probe_active_list); static atomic_t deferred_trigger_count = ATOMIC_INIT(0); +static ssize_t deferred_probe_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + bool value; + + mutex_lock(&deferred_probe_mutex); + value = !list_empty(&dev->p->deferred_probe); + mutex_unlock(&deferred_probe_mutex); + + return sprintf(buf, "%d\n", value); +} +DEVICE_ATTR_RO(deferred_probe); + /* * In some cases, like suspend to RAM or hibernation, It might be reasonable * to prohibit probing of devices as it could be unsafe. @@ -244,6 +257,7 @@ static void driver_bound(struct device *dev) __func__, dev_name(dev)); klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); + device_links_driver_bound(dev); device_pm_check_callbacks(dev); @@ -338,6 +352,10 @@ static int really_probe(struct device *dev, struct device_driver *drv) return ret; } + ret = device_links_check_suppliers(dev); + if (ret) + return ret; + atomic_inc(&probe_count); pr_debug("bus: '%s': %s: probing driver %s with device %s\n", drv->bus->name, __func__, drv->name, dev_name(dev)); @@ -416,6 +434,7 @@ probe_failed: blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev); pinctrl_bind_failed: + device_links_no_driver(dev); devres_release_all(dev); driver_sysfs_remove(dev); dev->driver = NULL; @@ -508,6 +527,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) pr_debug("bus: '%s': %s: matched device %s with driver %s\n", drv->bus->name, __func__, dev_name(dev), drv->name); + pm_runtime_get_suppliers(dev); if (dev->parent) pm_runtime_get_sync(dev->parent); @@ -518,6 +538,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) if (dev->parent) pm_runtime_put(dev->parent); + pm_runtime_put_suppliers(dev); return ret; } @@ -772,7 +793,7 @@ EXPORT_SYMBOL_GPL(driver_attach); * __device_release_driver() must be called with @dev lock held. * When called for a USB interface, @dev->parent lock must be held as well. */ -static void __device_release_driver(struct device *dev) +static void __device_release_driver(struct device *dev, struct device *parent) { struct device_driver *drv; @@ -781,7 +802,27 @@ static void __device_release_driver(struct device *dev) if (driver_allows_async_probing(drv)) async_synchronize_full(); + while (device_links_busy(dev)) { + device_unlock(dev); + if (parent) + device_unlock(parent); + + device_links_unbind_consumers(dev); + if (parent) + device_lock(parent); + + device_lock(dev); + /* + * A concurrent invocation of the same function might + * have released the driver successfully while this one + * was waiting, so check for that. + */ + if (dev->driver != drv) + return; + } + pm_runtime_get_sync(dev); + pm_runtime_clean_up_links(dev); driver_sysfs_remove(dev); @@ -796,6 +837,8 @@ static void __device_release_driver(struct device *dev) dev->bus->remove(dev); else if (drv->remove) drv->remove(dev); + + device_links_driver_cleanup(dev); devres_release_all(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL); @@ -812,12 +855,32 @@ static void __device_release_driver(struct device *dev) } } +void device_release_driver_internal(struct device *dev, + struct device_driver *drv, + struct device *parent) +{ + if (parent) + device_lock(parent); + + device_lock(dev); + if (!drv || drv == dev->driver) + __device_release_driver(dev, parent); + + device_unlock(dev); + if (parent) + device_unlock(parent); +} + /** * device_release_driver - manually detach device from driver. * @dev: device. * * Manually detach device from driver. * When called for a USB interface, @dev->parent lock must be held. + * + * If this function is to be called with @dev->parent lock held, ensure that + * the device's consumers are unbound in advance or that their locks can be + * acquired under the @dev->parent lock. */ void device_release_driver(struct device *dev) { @@ -826,9 +889,7 @@ void device_release_driver(struct device *dev) * within their ->remove callback for the same device, they * will deadlock right here. */ - device_lock(dev); - __device_release_driver(dev); - device_unlock(dev); + device_release_driver_internal(dev, NULL, NULL); } EXPORT_SYMBOL_GPL(device_release_driver); @@ -853,15 +914,7 @@ void driver_detach(struct device_driver *drv) dev = dev_prv->device; get_device(dev); spin_unlock(&drv->p->klist_devices.k_lock); - - if (dev->parent) /* Needed for USB */ - device_lock(dev->parent); - device_lock(dev); - if (dev->driver == drv) - __device_release_driver(dev); - device_unlock(dev); - if (dev->parent) - device_unlock(dev->parent); + device_release_driver_internal(dev, drv, dev->parent); put_device(dev); } } diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 240374f..7be310f 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -160,18 +160,20 @@ static ssize_t disabled_store(struct class *class, struct class_attribute *attr, return count; } +static CLASS_ATTR_RW(disabled); -static struct class_attribute devcd_class_attrs[] = { - __ATTR_RW(disabled), - __ATTR_NULL +static struct attribute *devcd_class_attrs[] = { + &class_attr_disabled.attr, + NULL, }; +ATTRIBUTE_GROUPS(devcd_class); static struct class devcd_class = { .name = "devcoredump", .owner = THIS_MODULE, .dev_release = devcd_dev_release, .dev_groups = devcd_dev_groups, - .class_attrs = devcd_class_attrs, + .class_groups = devcd_class_groups, }; static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 8f8b68c..efd71cf 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -108,13 +108,13 @@ void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, EXPORT_SYMBOL(dmam_free_coherent); /** - * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent() + * dmam_alloc_non_coherent - Managed dma_alloc_noncoherent() * @dev: Device to allocate non_coherent memory for * @size: Size of allocation * @dma_handle: Out argument for allocated DMA handle * @gfp: Allocation flags * - * Managed dma_alloc_non_coherent(). Memory allocated using this + * Managed dma_alloc_noncoherent(). Memory allocated using this * function will be automatically released on driver detach. * * RETURNS: diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 22d1760..4497d26 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -30,6 +30,7 @@ #include <linux/syscore_ops.h> #include <linux/reboot.h> #include <linux/security.h> +#include <linux/swait.h> #include <generated/utsrelease.h> @@ -91,10 +92,11 @@ static inline bool fw_is_builtin_firmware(const struct firmware *fw) } #endif -enum { +enum fw_status { + FW_STATUS_UNKNOWN, FW_STATUS_LOADING, FW_STATUS_DONE, - FW_STATUS_ABORT, + FW_STATUS_ABORTED, }; static int loading_timeout = 60; /* In seconds */ @@ -104,6 +106,82 @@ static inline long firmware_loading_timeout(void) return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET; } +/* + * Concurrent request_firmware() for the same firmware need to be + * serialized. struct fw_state is simple state machine which hold the + * state of the firmware loading. + */ +struct fw_state { + struct swait_queue_head wq; + enum fw_status status; +}; + +static void fw_state_init(struct fw_state *fw_st) +{ + init_swait_queue_head(&fw_st->wq); + fw_st->status = FW_STATUS_UNKNOWN; +} + +static inline bool __fw_state_is_done(enum fw_status status) +{ + return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED; +} + +static int __fw_state_wait_common(struct fw_state *fw_st, long timeout) +{ + long ret; + + ret = swait_event_interruptible_timeout(fw_st->wq, + __fw_state_is_done(READ_ONCE(fw_st->status)), + timeout); + if (ret != 0 && fw_st->status == FW_STATUS_ABORTED) + return -ENOENT; + if (!ret) + return -ETIMEDOUT; + + return ret < 0 ? ret : 0; +} + +static void __fw_state_set(struct fw_state *fw_st, + enum fw_status status) +{ + WRITE_ONCE(fw_st->status, status); + + if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) + swake_up(&fw_st->wq); +} + +#define fw_state_start(fw_st) \ + __fw_state_set(fw_st, FW_STATUS_LOADING) +#define fw_state_done(fw_st) \ + __fw_state_set(fw_st, FW_STATUS_DONE) +#define fw_state_wait(fw_st) \ + __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT) + +#ifndef CONFIG_FW_LOADER_USER_HELPER + +#define fw_state_is_aborted(fw_st) false + +#else /* CONFIG_FW_LOADER_USER_HELPER */ + +static int __fw_state_check(struct fw_state *fw_st, enum fw_status status) +{ + return fw_st->status == status; +} + +#define fw_state_aborted(fw_st) \ + __fw_state_set(fw_st, FW_STATUS_ABORTED) +#define fw_state_is_done(fw_st) \ + __fw_state_check(fw_st, FW_STATUS_DONE) +#define fw_state_is_loading(fw_st) \ + __fw_state_check(fw_st, FW_STATUS_LOADING) +#define fw_state_is_aborted(fw_st) \ + __fw_state_check(fw_st, FW_STATUS_ABORTED) +#define fw_state_wait_timeout(fw_st, timeout) \ + __fw_state_wait_common(fw_st, timeout) + +#endif /* CONFIG_FW_LOADER_USER_HELPER */ + /* firmware behavior options */ #define FW_OPT_UEVENT (1U << 0) #define FW_OPT_NOWAIT (1U << 1) @@ -145,9 +223,8 @@ struct firmware_cache { struct firmware_buf { struct kref ref; struct list_head list; - struct completion completion; struct firmware_cache *fwc; - unsigned long status; + struct fw_state fw_st; void *data; size_t size; size_t allocated_size; @@ -205,7 +282,7 @@ static struct firmware_buf *__allocate_fw_buf(const char *fw_name, buf->fwc = fwc; buf->data = dbuf; buf->allocated_size = size; - init_completion(&buf->completion); + fw_state_init(&buf->fw_st); #ifdef CONFIG_FW_LOADER_USER_HELPER INIT_LIST_HEAD(&buf->pending_list); #endif @@ -305,15 +382,6 @@ static const char * const fw_path[] = { module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644); MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path"); -static void fw_finish_direct_load(struct device *device, - struct firmware_buf *buf) -{ - mutex_lock(&fw_lock); - set_bit(FW_STATUS_DONE, &buf->status); - complete_all(&buf->completion); - mutex_unlock(&fw_lock); -} - static int fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf) { @@ -360,7 +428,7 @@ fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf) } dev_dbg(device, "direct-loading %s\n", buf->fw_id); buf->size = size; - fw_finish_direct_load(device, buf); + fw_state_done(&buf->fw_st); break; } __putname(path); @@ -478,12 +546,11 @@ static void __fw_load_abort(struct firmware_buf *buf) * There is a small window in which user can write to 'loading' * between loading done and disappearance of 'loading' */ - if (test_bit(FW_STATUS_DONE, &buf->status)) + if (fw_state_is_done(&buf->fw_st)) return; list_del_init(&buf->pending_list); - set_bit(FW_STATUS_ABORT, &buf->status); - complete_all(&buf->completion); + fw_state_aborted(&buf->fw_st); } static void fw_load_abort(struct firmware_priv *fw_priv) @@ -496,9 +563,6 @@ static void fw_load_abort(struct firmware_priv *fw_priv) fw_priv->buf = NULL; } -#define is_fw_load_aborted(buf) \ - test_bit(FW_STATUS_ABORT, &(buf)->status) - static LIST_HEAD(pending_fw_head); /* reboot notifier for avoid deadlock with usermode_lock */ @@ -546,11 +610,13 @@ static ssize_t timeout_store(struct class *class, struct class_attribute *attr, return count; } +static CLASS_ATTR_RW(timeout); -static struct class_attribute firmware_class_attrs[] = { - __ATTR_RW(timeout), - __ATTR_NULL +static struct attribute *firmware_class_attrs[] = { + &class_attr_timeout.attr, + NULL, }; +ATTRIBUTE_GROUPS(firmware_class); static void fw_dev_release(struct device *dev) { @@ -585,7 +651,7 @@ static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) static struct class firmware_class = { .name = "firmware", - .class_attrs = firmware_class_attrs, + .class_groups = firmware_class_groups, .dev_uevent = firmware_uevent, .dev_release = fw_dev_release, }; @@ -598,7 +664,7 @@ static ssize_t firmware_loading_show(struct device *dev, mutex_lock(&fw_lock); if (fw_priv->buf) - loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status); + loading = fw_state_is_loading(&fw_priv->buf->fw_st); mutex_unlock(&fw_lock); return sprintf(buf, "%d\n", loading); @@ -653,23 +719,20 @@ static ssize_t firmware_loading_store(struct device *dev, switch (loading) { case 1: /* discarding any previous partial load */ - if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) { + if (!fw_state_is_done(&fw_buf->fw_st)) { for (i = 0; i < fw_buf->nr_pages; i++) __free_page(fw_buf->pages[i]); vfree(fw_buf->pages); fw_buf->pages = NULL; fw_buf->page_array_size = 0; fw_buf->nr_pages = 0; - set_bit(FW_STATUS_LOADING, &fw_buf->status); + fw_state_start(&fw_buf->fw_st); } break; case 0: - if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) { + if (fw_state_is_loading(&fw_buf->fw_st)) { int rc; - set_bit(FW_STATUS_DONE, &fw_buf->status); - clear_bit(FW_STATUS_LOADING, &fw_buf->status); - /* * Several loading requests may be pending on * one same firmware buf, so let all requests @@ -691,10 +754,11 @@ static ssize_t firmware_loading_store(struct device *dev, */ list_del_init(&fw_buf->pending_list); if (rc) { - set_bit(FW_STATUS_ABORT, &fw_buf->status); + fw_state_aborted(&fw_buf->fw_st); written = rc; + } else { + fw_state_done(&fw_buf->fw_st); } - complete_all(&fw_buf->completion); break; } /* fallthrough */ @@ -755,7 +819,7 @@ static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj, mutex_lock(&fw_lock); buf = fw_priv->buf; - if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) { + if (!buf || fw_state_is_done(&buf->fw_st)) { ret_count = -ENODEV; goto out; } @@ -842,7 +906,7 @@ static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj, mutex_lock(&fw_lock); buf = fw_priv->buf; - if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) { + if (!buf || fw_state_is_done(&buf->fw_st)) { retval = -ENODEV; goto out; } @@ -955,17 +1019,14 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, timeout = MAX_JIFFY_OFFSET; } - retval = wait_for_completion_interruptible_timeout(&buf->completion, - timeout); - if (retval == -ERESTARTSYS || !retval) { + retval = fw_state_wait_timeout(&buf->fw_st, timeout); + if (retval < 0) { mutex_lock(&fw_lock); fw_load_abort(fw_priv); mutex_unlock(&fw_lock); - } else if (retval > 0) { - retval = 0; } - if (is_fw_load_aborted(buf)) + if (fw_state_is_aborted(&buf->fw_st)) retval = -EAGAIN; else if (buf->is_paged_buf && !buf->data) retval = -ENOMEM; @@ -1015,35 +1076,12 @@ fw_load_from_user_helper(struct firmware *firmware, const char *name, return -ENOENT; } -/* No abort during direct loading */ -#define is_fw_load_aborted(buf) false - #ifdef CONFIG_PM_SLEEP static inline void kill_requests_without_uevent(void) { } #endif #endif /* CONFIG_FW_LOADER_USER_HELPER */ - -/* wait until the shared firmware_buf becomes ready (or error) */ -static int sync_cached_firmware_buf(struct firmware_buf *buf) -{ - int ret = 0; - - mutex_lock(&fw_lock); - while (!test_bit(FW_STATUS_DONE, &buf->status)) { - if (is_fw_load_aborted(buf)) { - ret = -ENOENT; - break; - } - mutex_unlock(&fw_lock); - ret = wait_for_completion_interruptible(&buf->completion); - mutex_lock(&fw_lock); - } - mutex_unlock(&fw_lock); - return ret; -} - /* prepare firmware and firmware_buf structs; * return 0 if a firmware is already assigned, 1 if need to load one, * or a negative error code @@ -1077,7 +1115,7 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name, firmware->priv = buf; if (ret > 0) { - ret = sync_cached_firmware_buf(buf); + ret = fw_state_wait(&buf->fw_st); if (!ret) { fw_set_page_data(buf, firmware); return 0; /* assigned */ @@ -1095,7 +1133,7 @@ static int assign_firmware_buf(struct firmware *fw, struct device *device, struct firmware_buf *buf = fw->priv; mutex_lock(&fw_lock); - if (!buf->size || is_fw_load_aborted(buf)) { + if (!buf->size || fw_state_is_aborted(&buf->fw_st)) { mutex_unlock(&fw_lock); return -ENOENT; } @@ -1345,9 +1383,9 @@ static void request_firmware_work_func(struct work_struct *work) * * Asynchronous variant of request_firmware() for user contexts: * - sleep for as small periods as possible since it may - * increase kernel boot time of built-in device drivers - * requesting firmware in their ->probe() methods, if - * @gfp is GFP_KERNEL. + * increase kernel boot time of built-in device drivers + * requesting firmware in their ->probe() methods, if + * @gfp is GFP_KERNEL. * * - can't sleep at all if @gfp is GFP_ATOMIC. **/ diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 62c63c0..bb69e58 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -226,11 +226,9 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t { unsigned long start_pfn; unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; - struct page *first_page; int ret; start_pfn = section_nr_to_pfn(phys_index); - first_page = pfn_to_page(start_pfn); switch (action) { case MEM_ONLINE: diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index eb474c8..48c6294 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -131,6 +131,7 @@ void device_pm_add(struct device *dev) dev_warn(dev, "parent %s should not be sleeping\n", dev_name(dev->parent)); list_add_tail(&dev->power.entry, &dpm_list); + dev->power.in_dpm_list = true; mutex_unlock(&dpm_list_mtx); } @@ -145,6 +146,7 @@ void device_pm_remove(struct device *dev) complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); list_del_init(&dev->power.entry); + dev->power.in_dpm_list = false; mutex_unlock(&dpm_list_mtx); device_wakeup_disable(dev); pm_runtime_remove(dev); @@ -244,6 +246,62 @@ static void dpm_wait_for_children(struct device *dev, bool async) device_for_each_child(dev, &async, dpm_wait_fn); } +static void dpm_wait_for_suppliers(struct device *dev, bool async) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + /* + * If the supplier goes away right after we've checked the link to it, + * we'll wait for its completion to change the state, but that's fine, + * because the only things that will block as a result are the SRCU + * callbacks freeing the link objects for the links in the list we're + * walking. + */ + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + if (READ_ONCE(link->status) != DL_STATE_DORMANT) + dpm_wait(link->supplier, async); + + device_links_read_unlock(idx); +} + +static void dpm_wait_for_superior(struct device *dev, bool async) +{ + dpm_wait(dev->parent, async); + dpm_wait_for_suppliers(dev, async); +} + +static void dpm_wait_for_consumers(struct device *dev, bool async) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + /* + * The status of a device link can only be changed from "dormant" by a + * probe, but that cannot happen during system suspend/resume. In + * theory it can change to "dormant" at that time, but then it is + * reasonable to wait for the target device anyway (eg. if it goes + * away, it's better to wait for it to go away completely and then + * continue instead of trying to continue in parallel with its + * unregistration). + */ + list_for_each_entry_rcu(link, &dev->links.consumers, s_node) + if (READ_ONCE(link->status) != DL_STATE_DORMANT) + dpm_wait(link->consumer, async); + + device_links_read_unlock(idx); +} + +static void dpm_wait_for_subordinate(struct device *dev, bool async) +{ + dpm_wait_for_children(dev, async); + dpm_wait_for_consumers(dev, async); +} + /** * pm_op - Return the PM operation appropriate for given PM event. * @ops: PM operations to choose from. @@ -488,7 +546,7 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dev->power.is_noirq_suspended) goto Out; - dpm_wait(dev->parent, async); + dpm_wait_for_superior(dev, async); if (dev->pm_domain) { info = "noirq power domain "; @@ -618,7 +676,7 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn if (!dev->power.is_late_suspended) goto Out; - dpm_wait(dev->parent, async); + dpm_wait_for_superior(dev, async); if (dev->pm_domain) { info = "early power domain "; @@ -750,7 +808,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) goto Complete; } - dpm_wait(dev->parent, async); + dpm_wait_for_superior(dev, async); dpm_watchdog_set(&wd, dev); device_lock(dev); @@ -1027,7 +1085,7 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a TRACE_DEVICE(dev); TRACE_SUSPEND(0); - dpm_wait_for_children(dev, async); + dpm_wait_for_subordinate(dev, async); if (async_error) goto Complete; @@ -1174,7 +1232,7 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as __pm_runtime_disable(dev, false); - dpm_wait_for_children(dev, async); + dpm_wait_for_subordinate(dev, async); if (async_error) goto Complete; @@ -1342,6 +1400,22 @@ static int legacy_suspend(struct device *dev, pm_message_t state, return error; } +static void dpm_clear_suppliers_direct_complete(struct device *dev) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { + spin_lock_irq(&link->supplier->power.lock); + link->supplier->power.direct_complete = false; + spin_unlock_irq(&link->supplier->power.lock); + } + + device_links_read_unlock(idx); +} + /** * device_suspend - Execute "suspend" callbacks for given device. * @dev: Device to handle. @@ -1358,7 +1432,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) TRACE_DEVICE(dev); TRACE_SUSPEND(0); - dpm_wait_for_children(dev, async); + dpm_wait_for_subordinate(dev, async); if (async_error) goto Complete; @@ -1454,6 +1528,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) spin_unlock_irq(&parent->power.lock); } + dpm_clear_suppliers_direct_complete(dev); } device_unlock(dev); diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index a84332a..a46e97e 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -144,6 +144,11 @@ extern void device_pm_move_after(struct device *, struct device *); extern void device_pm_move_last(struct device *); extern void device_pm_check_callbacks(struct device *dev); +static inline bool device_pm_initialized(struct device *dev) +{ + return dev->power.in_dpm_list; +} + #else /* !CONFIG_PM_SLEEP */ static inline void device_pm_sleep_init(struct device *dev) {} @@ -163,6 +168,11 @@ static inline void device_pm_move_last(struct device *dev) {} static inline void device_pm_check_callbacks(struct device *dev) {} +static inline bool device_pm_initialized(struct device *dev) +{ + return device_is_registered(dev); +} + #endif /* !CONFIG_PM_SLEEP */ static inline void device_pm_init(struct device *dev) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 26856d0..872eac4 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -12,6 +12,8 @@ #include <linux/pm_runtime.h> #include <linux/pm_wakeirq.h> #include <trace/events/rpm.h> + +#include "../base.h" #include "power.h" typedef int (*pm_callback_t)(struct device *); @@ -259,6 +261,42 @@ static int rpm_check_suspend_allowed(struct device *dev) return retval; } +static int rpm_get_suppliers(struct device *dev) +{ + struct device_link *link; + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { + int retval; + + if (!(link->flags & DL_FLAG_PM_RUNTIME)) + continue; + + if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND || + link->rpm_active) + continue; + + retval = pm_runtime_get_sync(link->supplier); + if (retval < 0) { + pm_runtime_put_noidle(link->supplier); + return retval; + } + link->rpm_active = true; + } + return 0; +} + +static void rpm_put_suppliers(struct device *dev) +{ + struct device_link *link; + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + if (link->rpm_active && + READ_ONCE(link->status) != DL_STATE_SUPPLIER_UNBIND) { + pm_runtime_put(link->supplier); + link->rpm_active = false; + } +} + /** * __rpm_callback - Run a given runtime PM callback for a given device. * @cb: Runtime PM callback to run. @@ -267,19 +305,57 @@ static int rpm_check_suspend_allowed(struct device *dev) static int __rpm_callback(int (*cb)(struct device *), struct device *dev) __releases(&dev->power.lock) __acquires(&dev->power.lock) { - int retval; + int retval, idx; + bool use_links = dev->power.links_count > 0; - if (dev->power.irq_safe) + if (dev->power.irq_safe) { spin_unlock(&dev->power.lock); - else + } else { spin_unlock_irq(&dev->power.lock); + /* + * Resume suppliers if necessary. + * + * The device's runtime PM status cannot change until this + * routine returns, so it is safe to read the status outside of + * the lock. + */ + if (use_links && dev->power.runtime_status == RPM_RESUMING) { + idx = device_links_read_lock(); + + retval = rpm_get_suppliers(dev); + if (retval) + goto fail; + + device_links_read_unlock(idx); + } + } + retval = cb(dev); - if (dev->power.irq_safe) + if (dev->power.irq_safe) { spin_lock(&dev->power.lock); - else + } else { + /* + * If the device is suspending and the callback has returned + * success, drop the usage counters of the suppliers that have + * been reference counted on its resume. + * + * Do that if resume fails too. + */ + if (use_links + && ((dev->power.runtime_status == RPM_SUSPENDING && !retval) + || (dev->power.runtime_status == RPM_RESUMING && retval))) { + idx = device_links_read_lock(); + + fail: + rpm_put_suppliers(dev); + + device_links_read_unlock(idx); + } + spin_lock_irq(&dev->power.lock); + } return retval; } @@ -1458,6 +1534,94 @@ void pm_runtime_remove(struct device *dev) } /** + * pm_runtime_clean_up_links - Prepare links to consumers for driver removal. + * @dev: Device whose driver is going to be removed. + * + * Check links from this device to any consumers and if any of them have active + * runtime PM references to the device, drop the usage counter of the device + * (once per link). + * + * Links with the DL_FLAG_STATELESS flag set are ignored. + * + * Since the device is guaranteed to be runtime-active at the point this is + * called, nothing else needs to be done here. + * + * Moreover, this is called after device_links_busy() has returned 'false', so + * the status of each link is guaranteed to be DL_STATE_SUPPLIER_UNBIND and + * therefore rpm_active can't be manipulated concurrently. + */ +void pm_runtime_clean_up_links(struct device *dev) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.consumers, s_node) { + if (link->flags & DL_FLAG_STATELESS) + continue; + + if (link->rpm_active) { + pm_runtime_put_noidle(dev); + link->rpm_active = false; + } + } + + device_links_read_unlock(idx); +} + +/** + * pm_runtime_get_suppliers - Resume and reference-count supplier devices. + * @dev: Consumer device. + */ +void pm_runtime_get_suppliers(struct device *dev) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + if (link->flags & DL_FLAG_PM_RUNTIME) + pm_runtime_get_sync(link->supplier); + + device_links_read_unlock(idx); +} + +/** + * pm_runtime_put_suppliers - Drop references to supplier devices. + * @dev: Consumer device. + */ +void pm_runtime_put_suppliers(struct device *dev) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + if (link->flags & DL_FLAG_PM_RUNTIME) + pm_runtime_put(link->supplier); + + device_links_read_unlock(idx); +} + +void pm_runtime_new_link(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + dev->power.links_count++; + spin_unlock_irq(&dev->power.lock); +} + +void pm_runtime_drop_link(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + WARN_ON(dev->power.links_count == 0); + dev->power.links_count--; + spin_unlock_irq(&dev->power.lock); +} + +/** * pm_runtime_force_suspend - Force a device into suspend state if needed. * @dev: Device to suspend. * diff --git a/drivers/base/test/Kconfig b/drivers/base/test/Kconfig new file mode 100644 index 0000000..9aa0d45 --- /dev/null +++ b/drivers/base/test/Kconfig @@ -0,0 +1,9 @@ +config TEST_ASYNC_DRIVER_PROBE + tristate "Build kernel module to test asynchronous driver probing" + depends on m + help + Enabling this option produces a kernel module that allows + testing asynchronous driver probing by the device core. + The module name will be test_async_driver_probe.ko + + If unsure say N. diff --git a/drivers/base/test/Makefile b/drivers/base/test/Makefile new file mode 100644 index 0000000..90477c5 --- /dev/null +++ b/drivers/base/test/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_TEST_ASYNC_DRIVER_PROBE) += test_async_driver_probe.o diff --git a/drivers/base/test/test_async_driver_probe.c b/drivers/base/test/test_async_driver_probe.c new file mode 100644 index 0000000..304d5c2 --- /dev/null +++ b/drivers/base/test/test_async_driver_probe.c @@ -0,0 +1,169 @@ +/* + * Copyright (C) 2014 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/hrtimer.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/time.h> + +#define TEST_PROBE_DELAY (5 * 1000) /* 5 sec */ +#define TEST_PROBE_THRESHOLD (TEST_PROBE_DELAY / 2) + +static int test_probe(struct platform_device *pdev) +{ + dev_info(&pdev->dev, "sleeping for %d msecs in probe\n", + TEST_PROBE_DELAY); + msleep(TEST_PROBE_DELAY); + dev_info(&pdev->dev, "done sleeping\n"); + + return 0; +} + +static struct platform_driver async_driver = { + .driver = { + .name = "test_async_driver", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, + .probe = test_probe, +}; + +static struct platform_driver sync_driver = { + .driver = { + .name = "test_sync_driver", + .probe_type = PROBE_FORCE_SYNCHRONOUS, + }, + .probe = test_probe, +}; + +static struct platform_device *async_dev_1, *async_dev_2; +static struct platform_device *sync_dev_1; + +static int __init test_async_probe_init(void) +{ + ktime_t calltime, delta; + unsigned long long duration; + int error; + + pr_info("registering first asynchronous device...\n"); + + async_dev_1 = platform_device_register_simple("test_async_driver", 1, + NULL, 0); + if (IS_ERR(async_dev_1)) { + error = PTR_ERR(async_dev_1); + pr_err("failed to create async_dev_1: %d", error); + return error; + } + + pr_info("registering asynchronous driver...\n"); + calltime = ktime_get(); + error = platform_driver_register(&async_driver); + if (error) { + pr_err("Failed to register async_driver: %d\n", error); + goto err_unregister_async_dev_1; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration > TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe took too long\n"); + error = -ETIMEDOUT; + goto err_unregister_async_driver; + } + + pr_info("registering second asynchronous device...\n"); + calltime = ktime_get(); + async_dev_2 = platform_device_register_simple("test_async_driver", 2, + NULL, 0); + if (IS_ERR(async_dev_2)) { + error = PTR_ERR(async_dev_2); + pr_err("failed to create async_dev_2: %d", error); + goto err_unregister_async_driver; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration > TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe took too long\n"); + error = -ETIMEDOUT; + goto err_unregister_async_dev_2; + } + + pr_info("registering synchronous driver...\n"); + + error = platform_driver_register(&sync_driver); + if (error) { + pr_err("Failed to register async_driver: %d\n", error); + goto err_unregister_async_dev_2; + } + + pr_info("registering synchronous device...\n"); + calltime = ktime_get(); + sync_dev_1 = platform_device_register_simple("test_sync_driver", 1, + NULL, 0); + if (IS_ERR(sync_dev_1)) { + error = PTR_ERR(sync_dev_1); + pr_err("failed to create sync_dev_1: %d", error); + goto err_unregister_sync_driver; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration < TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe was too quick\n"); + error = -ETIMEDOUT; + goto err_unregister_sync_dev_1; + } + + pr_info("completed successfully"); + + return 0; + +err_unregister_sync_dev_1: + platform_device_unregister(sync_dev_1); + +err_unregister_sync_driver: + platform_driver_unregister(&sync_driver); + +err_unregister_async_dev_2: + platform_device_unregister(async_dev_2); + +err_unregister_async_driver: + platform_driver_unregister(&async_driver); + +err_unregister_async_dev_1: + platform_device_unregister(async_dev_1); + + return error; +} +module_init(test_async_probe_init); + +static void __exit test_async_probe_exit(void) +{ + platform_driver_unregister(&async_driver); + platform_driver_unregister(&sync_driver); + platform_device_unregister(async_dev_1); + platform_device_unregister(async_dev_2); + platform_device_unregister(sync_dev_1); +} +module_exit(test_async_probe_exit); + +MODULE_DESCRIPTION("Test module for asynchronous driver probing"); +MODULE_AUTHOR("Dmitry Torokhov <dtor@chromium.org>"); +MODULE_LICENSE("GPL"); diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index a198211..ac9e108 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -335,7 +335,7 @@ static int kernfs_xattr_set(const struct xattr_handler *handler, return simple_xattr_set(&attrs->xattrs, name, value, size, flags); } -const struct xattr_handler kernfs_trusted_xattr_handler = { +static const struct xattr_handler kernfs_trusted_xattr_handler = { .prefix = XATTR_TRUSTED_PREFIX, .get = kernfs_xattr_get, .set = kernfs_xattr_set, @@ -372,7 +372,7 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler, return error; } -const struct xattr_handler kernfs_security_xattr_handler = { +static const struct xattr_handler kernfs_security_xattr_handler = { .prefix = XATTR_SECURITY_PREFIX, .get = kernfs_xattr_get, .set = kernfs_security_xattr_set, diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h index 2189935..a951fd1 100644 --- a/include/linux/cacheinfo.h +++ b/include/linux/cacheinfo.h @@ -71,6 +71,7 @@ struct cpu_cacheinfo { struct cacheinfo *info_list; unsigned int num_levels; unsigned int num_leaves; + bool cpu_map_populated; }; /* diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index bf1907d..014cc56 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -63,6 +63,21 @@ debugfs_real_fops(const struct file *filp) return filp->f_path.dentry->d_fsdata; } +#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ +static int __fops ## _open(struct inode *inode, struct file *file) \ +{ \ + __simple_attr_check_format(__fmt, 0ull); \ + return simple_attr_open(inode, file, __get, __set, __fmt); \ +} \ +static const struct file_operations __fops = { \ + .owner = THIS_MODULE, \ + .open = __fops ## _open, \ + .release = simple_attr_release, \ + .read = debugfs_attr_read, \ + .write = debugfs_attr_write, \ + .llseek = generic_file_llseek, \ +} + #if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_create_file(const char *name, umode_t mode, @@ -100,21 +115,6 @@ ssize_t debugfs_attr_read(struct file *file, char __user *buf, ssize_t debugfs_attr_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos); -#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ -static int __fops ## _open(struct inode *inode, struct file *file) \ -{ \ - __simple_attr_check_format(__fmt, 0ull); \ - return simple_attr_open(inode, file, __get, __set, __fmt); \ -} \ -static const struct file_operations __fops = { \ - .owner = THIS_MODULE, \ - .open = __fops ## _open, \ - .release = simple_attr_release, \ - .read = debugfs_attr_read, \ - .write = debugfs_attr_write, \ - .llseek = generic_file_llseek, \ -} - struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, struct dentry *new_dir, const char *new_name); @@ -234,8 +234,18 @@ static inline void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu) { } -#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ - static const struct file_operations __fops = { 0 } +static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos) +{ + return -ENODEV; +} + +static inline ssize_t debugfs_attr_write(struct file *file, + const char __user *buf, + size_t len, loff_t *ppos) +{ + return -ENODEV; +} static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, struct dentry *new_dir, char *new_name) diff --git a/include/linux/device.h b/include/linux/device.h index 94926d3..491b4c0c 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -362,6 +362,7 @@ int subsys_virtual_register(struct bus_type *subsys, * @name: Name of the class. * @owner: The module owner. * @class_attrs: Default attributes of this class. + * @class_groups: Default attributes of this class. * @dev_groups: Default attributes of the devices that belong to the class. * @dev_kobj: The kobject that represents this class and links it into the hierarchy. * @dev_uevent: Called when a device is added, removed from this class, or a @@ -390,6 +391,7 @@ struct class { struct module *owner; struct class_attribute *class_attrs; + const struct attribute_group **class_groups; const struct attribute_group **dev_groups; struct kobject *dev_kobj; @@ -465,6 +467,8 @@ struct class_attribute { struct class_attribute class_attr_##_name = __ATTR_RW(_name) #define CLASS_ATTR_RO(_name) \ struct class_attribute class_attr_##_name = __ATTR_RO(_name) +#define CLASS_ATTR_WO(_name) \ + struct class_attribute class_attr_##_name = __ATTR_WO(_name) extern int __must_check class_create_file_ns(struct class *class, const struct class_attribute *attr, @@ -727,6 +731,87 @@ struct device_dma_parameters { }; /** + * enum device_link_state - Device link states. + * @DL_STATE_NONE: The presence of the drivers is not being tracked. + * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present. + * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not. + * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present). + * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present. + * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding. + */ +enum device_link_state { + DL_STATE_NONE = -1, + DL_STATE_DORMANT = 0, + DL_STATE_AVAILABLE, + DL_STATE_CONSUMER_PROBE, + DL_STATE_ACTIVE, + DL_STATE_SUPPLIER_UNBIND, +}; + +/* + * Device link flags. + * + * STATELESS: The core won't track the presence of supplier/consumer drivers. + * AUTOREMOVE: Remove this link automatically on consumer driver unbind. + * PM_RUNTIME: If set, the runtime PM framework will use this link. + * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation. + */ +#define DL_FLAG_STATELESS BIT(0) +#define DL_FLAG_AUTOREMOVE BIT(1) +#define DL_FLAG_PM_RUNTIME BIT(2) +#define DL_FLAG_RPM_ACTIVE BIT(3) + +/** + * struct device_link - Device link representation. + * @supplier: The device on the supplier end of the link. + * @s_node: Hook to the supplier device's list of links to consumers. + * @consumer: The device on the consumer end of the link. + * @c_node: Hook to the consumer device's list of links to suppliers. + * @status: The state of the link (with respect to the presence of drivers). + * @flags: Link flags. + * @rpm_active: Whether or not the consumer device is runtime-PM-active. + * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks. + */ +struct device_link { + struct device *supplier; + struct list_head s_node; + struct device *consumer; + struct list_head c_node; + enum device_link_state status; + u32 flags; + bool rpm_active; +#ifdef CONFIG_SRCU + struct rcu_head rcu_head; +#endif +}; + +/** + * enum dl_dev_state - Device driver presence tracking information. + * @DL_DEV_NO_DRIVER: There is no driver attached to the device. + * @DL_DEV_PROBING: A driver is probing. + * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device. + * @DL_DEV_UNBINDING: The driver is unbinding from the device. + */ +enum dl_dev_state { + DL_DEV_NO_DRIVER = 0, + DL_DEV_PROBING, + DL_DEV_DRIVER_BOUND, + DL_DEV_UNBINDING, +}; + +/** + * struct dev_links_info - Device data related to device links. + * @suppliers: List of links to supplier devices. + * @consumers: List of links to consumer devices. + * @status: Driver status information. + */ +struct dev_links_info { + struct list_head suppliers; + struct list_head consumers; + enum dl_dev_state status; +}; + +/** * struct device - The basic device structure * @parent: The device's "parent" device, the device to which it is attached. * In most cases, a parent device is some sort of bus or host @@ -751,6 +836,7 @@ struct device_dma_parameters { * on. This shrinks the "Board Support Packages" (BSPs) and * minimizes board-specific #ifdefs in drivers. * @driver_data: Private pointer for driver specific info. + * @links: Links to suppliers and consumers of this device. * @power: For device power management. * See Documentation/power/admin-guide/devices.rst for details. * @pm_domain: Provide callbacks that are executed during system suspend, @@ -818,6 +904,7 @@ struct device { core doesn't touch it */ void *driver_data; /* Driver data, set and get with dev_set/get_drvdata */ + struct dev_links_info links; struct dev_pm_info power; struct dev_pm_domain *pm_domain; @@ -1135,6 +1222,10 @@ extern void device_shutdown(void); /* debugging and troubleshooting/diagnostic helpers. */ extern const char *dev_driver_string(const struct device *dev); +/* Device links interface. */ +struct device_link *device_link_add(struct device *consumer, + struct device *supplier, u32 flags); +void device_link_del(struct device_link *link); #ifdef CONFIG_PRINTK diff --git a/include/linux/pm.h b/include/linux/pm.h index efa67b2..f926af4 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -559,6 +559,7 @@ struct dev_pm_info { pm_message_t power_state; unsigned int can_wakeup:1; unsigned int async_suspend:1; + bool in_dpm_list:1; /* Owned by the PM core */ bool is_prepared:1; /* Owned by the PM core */ bool is_suspended:1; /* Ditto */ bool is_noirq_suspended:1; @@ -596,6 +597,7 @@ struct dev_pm_info { unsigned int use_autosuspend:1; unsigned int timer_autosuspends:1; unsigned int memalloc_noio:1; + unsigned int links_count; enum rpm_request request; enum rpm_status runtime_status; int runtime_error; diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 4957fc1..ca4823e 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -55,6 +55,11 @@ extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev); extern void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns); extern void pm_runtime_set_memalloc_noio(struct device *dev, bool enable); +extern void pm_runtime_clean_up_links(struct device *dev); +extern void pm_runtime_get_suppliers(struct device *dev); +extern void pm_runtime_put_suppliers(struct device *dev); +extern void pm_runtime_new_link(struct device *dev); +extern void pm_runtime_drop_link(struct device *dev); static inline void pm_suspend_ignore_children(struct device *dev, bool enable) { @@ -179,6 +184,11 @@ static inline unsigned long pm_runtime_autosuspend_expiration( struct device *dev) { return 0; } static inline void pm_runtime_set_memalloc_noio(struct device *dev, bool enable){} +static inline void pm_runtime_clean_up_links(struct device *dev) {} +static inline void pm_runtime_get_suppliers(struct device *dev) {} +static inline void pm_runtime_put_suppliers(struct device *dev) {} +static inline void pm_runtime_new_link(struct device *dev) {} +static inline void pm_runtime_drop_link(struct device *dev) {} #endif /* !CONFIG_PM */ diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index f6c2c1e..9a2b811 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -56,7 +56,7 @@ static const char *kobject_actions[] = { * kobject_action_type - translate action string to numeric type * * @buf: buffer containing the action string, newline is ignored - * @len: length of buffer + * @count: length of buffer * @type: pointer to the location to store the action type * * Returns 0 if the action string was recognized. @@ -154,8 +154,8 @@ static void cleanup_uevent_env(struct subprocess_info *info) /** * kobject_uevent_env - send an uevent with environmental data * - * @action: action that is happening * @kobj: struct kobject that the action is happening to + * @action: action that is happening * @envp_ext: pointer to environmental data * * Returns 0 if kobject_uevent_env() is completed with success or the @@ -363,8 +363,8 @@ EXPORT_SYMBOL_GPL(kobject_uevent_env); /** * kobject_uevent - notify userspace by sending an uevent * - * @action: action that is happening * @kobj: struct kobject that the action is happening to + * @action: action that is happening * * Returns 0 if kobject_uevent() is completed with success or the * corresponding error when it fails. |