/* * Componentized device handling. * * 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 is work in progress. We gather up the component devices into a list, * and bind them when instructed. At the moment, we're specific to the DRM * subsystem, and only handles one master device, but this doesn't have to be * the case. */#include <linux/component.h>#include <linux/device.h>#include <linux/kref.h>#include <linux/list.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/slab.h> struct component_match { size_t alloc; size_t num; struct { void *data; int (*fn)(struct device *, void *); } compare[0];}; struct master { struct list_head node; struct list_head components; bool bound; const struct component_master_ops *ops; struct device *dev; struct component_match *match;}; struct component { struct list_head node; struct list_head master_node; struct master *master; bool bound; const struct component_ops *ops; struct device *dev;}; static DEFINE_MUTEX(component_mutex);static LIST_HEAD(component_list);static LIST_HEAD(masters); static struct master *__master_find(struct device *dev, const struct component_master_ops *ops){ struct master *m; list_for_each_entry(m, &masters, node) if (m->dev == dev && (!ops || m->ops == ops)) return m; return NULL;} /* Attach an unattached component to a master. */static void component_attach_master(struct master *master, struct component *c){ c->master = master; list_add_tail(&c->master_node, &master->components);} /* Detach a component from a master. */static void component_detach_master(struct master *master, struct component *c){ list_del(&c->master_node); c->master = NULL;} /* * Add a component to a master, finding the component via the compare * function and compare data. This is safe to call for duplicate matches * and will not result in the same component being added multiple times. */int component_master_add_child(struct master *master, int (*compare)(struct device *, void *), void *compare_data){ struct component *c; int ret = -ENXIO; list_for_each_entry(c, &component_list, node) { if (c->master && c->master != master) continue; if (compare(c->dev, compare_data)) { if (!c->master) component_attach_master(master, c); ret = 0; break; } } return ret;}EXPORT_SYMBOL_GPL(component_master_add_child); static int find_components(struct master *master){ struct component_match *match = master->match; size_t i; int ret = 0; if (!match) { /* * Search the list of components, looking for components that * belong to this master, and attach them to the master. */ return master->ops->add_components(master->dev, master); } /* * Scan the array of match functions and attach * any components which are found to this master. */ for (i = 0; i < match->num; i++) { ret = component_master_add_child(master, match->compare[i].fn, match->compare[i].data); if (ret) break; } return ret;} /* Detach all attached components from this master */static void master_remove_components(struct master *master){ while (!list_empty(&master->components)) { struct component *c = list_first_entry(&master->components, struct component, master_node); WARN_ON(c->master != master); component_detach_master(master, c); }} /* * Try to bring up a master. If component is NULL, we're interested in * this master, otherwise it's a component which must be present to try * and bring up the master. * * Returns 1 for successful bringup, 0 if not ready, or -ve errno. */static int try_to_bring_up_master(struct master *master, struct component *component){ int ret; if (master->bound) return 0; /* * Search the list of components, looking for components that * belong to this master, and attach them to the master. */ if (find_components(master)) { /* Failed to find all components */ ret = 0; goto out; } if (component && component->master != master) { ret = 0; goto out; } if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) { ret = -ENOMEM; goto out; } /* Found all components */ ret = master->ops->bind(master->dev); if (ret < 0) { devres_release_group(master->dev, NULL); dev_info(master->dev, "master bind failed: %d\n", ret); goto out; } master->bound = true; return 1; out: master_remove_components(master); return ret;} static int try_to_bring_up_masters(struct component *component){ struct master *m; int ret = 0; list_for_each_entry(m, &masters, node) { ret = try_to_bring_up_master(m, component); if (ret != 0) break; } return ret;} static void take_down_master(struct master *master){ if (master->bound) { master->ops->unbind(master->dev); devres_release_group(master->dev, NULL); master->bound = false; } master_remove_components(master);} static size_t component_match_size(size_t num){ return offsetof(struct component_match, compare[num]);} static struct component_match *component_match_realloc(struct device *dev, struct component_match *match, size_t num){ struct component_match *new; if (match && match->alloc == num) return match; new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL); if (!new) return ERR_PTR(-ENOMEM); if (match) { memcpy(new, match, component_match_size(min(match->num, num))); devm_kfree(dev, match); } else { new->num = 0; } new->alloc = num; return new;} /* * Add a component to be matched. * * The match array is first created or extended if necessary. */void component_match_add(struct device *dev, struct component_match **matchptr, int (*compare)(struct device *, void *), void *compare_data){ struct component_match *match = *matchptr; if (IS_ERR(match)) return; if (!match || match->num == match->alloc) { size_t new_size = match ? match->alloc + 16 : 15; match = component_match_realloc(dev, match, new_size); *matchptr = match; if (IS_ERR(match)) return; } match->compare[match->num].fn = compare; match->compare[match->num].data = compare_data; match->num++;}EXPORT_SYMBOL(component_match_add); int component_master_add_with_match(struct device *dev, const struct component_master_ops *ops, struct component_match *match){ struct master *master; int ret; if (ops->add_components && match) return -EINVAL; if (match) { /* Reallocate the match array for its true size */ match = component_match_realloc(dev, match, match->num); if (IS_ERR(match)) return PTR_ERR(match); } master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return -ENOMEM; master->dev = dev; master->ops = ops; master->match = match; INIT_LIST_HEAD(&master->components); /* Add to the list of available masters. */ mutex_lock(&component_mutex); list_add(&master->node, &masters); ret = try_to_bring_up_master(master, NULL); if (ret < 0) { /* Delete off the list if we weren't successful */ list_del(&master->node); kfree(master); } mutex_unlock(&component_mutex); return ret < 0 ? ret : 0;}EXPORT_SYMBOL_GPL(component_master_add_with_match); int component_master_add(struct device *dev, const struct component_master_ops *ops){ return component_master_add_with_match(dev, ops, NULL);}EXPORT_SYMBOL_GPL(component_master_add); void component_master_del(struct device *dev, const struct component_master_ops *ops){ struct master *master; mutex_lock(&component_mutex); master = __master_find(dev, ops); if (master) { take_down_master(master); list_del(&master->node); kfree(master); } mutex_unlock(&component_mutex);}EXPORT_SYMBOL_GPL(component_master_del); static void component_unbind(struct component *component, struct master *master, void *data){ WARN_ON(!component->bound); component->ops->unbind(component->dev, master->dev, data); component->bound = false; /* Release all resources claimed in the binding of this component */ devres_release_group(component->dev, component);} void component_unbind_all(struct device *master_dev, void *data){ struct master *master; struct component *c; WARN_ON(!mutex_is_locked(&component_mutex)); master = __master_find(master_dev, NULL); if (!master) return; list_for_each_entry_reverse(c, &master->components, master_node) component_unbind(c, master, data);}EXPORT_SYMBOL_GPL(component_unbind_all); static int component_bind(struct component *component, struct master *master, void *data){ int ret; /* * Each component initialises inside its own devres group. * This allows us to roll-back a failed component without * affecting anything else. */ if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) return -ENOMEM; /* * Also open a group for the device itself: this allows us * to release the resources claimed against the sub-device * at the appropriate moment. */ if (!devres_open_group(component->dev, component, GFP_KERNEL)) { devres_release_group(master->dev, NULL); return -ENOMEM; } dev_dbg(master->dev, "binding %s (ops %ps)\n", dev_name(component->dev), component->ops); ret = component->ops->bind(component->dev, master->dev, data); if (!ret) { component->bound = true; /* * Close the component device's group so that resources * allocated in the binding are encapsulated for removal * at unbind. Remove the group on the DRM device as we * can clean those resources up independently. */ devres_close_group(component->dev, NULL); devres_remove_group(master->dev, NULL); dev_info(master->dev, "bound %s (ops %ps)\n", dev_name(component->dev), component->ops); } else { devres_release_group(component->dev, NULL); devres_release_group(master->dev, NULL); dev_err(master->dev, "failed to bind %s (ops %ps): %d\n", dev_name(component->dev), component->ops, ret); } return ret;} int component_bind_all(struct device *master_dev, void *data){ struct master *master; struct component *c; int ret = 0; WARN_ON(!mutex_is_locked(&component_mutex)); master = __master_find(master_dev, NULL); if (!master) return -EINVAL; list_for_each_entry(c, &master->components, master_node) { ret = component_bind(c, master, data); if (ret) break; } if (ret != 0) { list_for_each_entry_continue_reverse(c, &master->components, master_node) component_unbind(c, master, data); } return ret;}EXPORT_SYMBOL_GPL(component_bind_all); int component_add(struct device *dev, const struct component_ops *ops){ struct component *component; int ret; component = kzalloc(sizeof(*component), GFP_KERNEL); if (!component) return -ENOMEM; component->ops = ops; component->dev = dev; dev_dbg(dev, "adding component (ops %ps)\n", ops); mutex_lock(&component_mutex); list_add_tail(&component->node, &component_list); ret = try_to_bring_up_masters(component); if (ret < 0) { list_del(&component->node); kfree(component); } mutex_unlock(&component_mutex); return ret < 0 ? ret : 0;}EXPORT_SYMBOL_GPL(component_add); void component_del(struct device *dev, const struct component_ops *ops){ struct component *c, *component = NULL; mutex_lock(&component_mutex); list_for_each_entry(c, &component_list, node) if (c->dev == dev && c->ops == ops) { list_del(&c->node); component = c; break; }Lines 1–500 of 512. 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/* * Componentized device handling. * * 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 is work in progress. We gather up the component devices into a list, * and bind them when instructed. At the moment, we're specific to the DRM * subsystem, and only handles one master device, but this doesn't have to be * the case. */ #include <linux/component.h> #include <linux/device.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> struct component_match { size_t alloc; size_t num; struct { void *data; int (*fn)(struct device *, void *); } compare[0]; }; struct master { struct list_head node; struct list_head components; bool bound; const struct component_master_ops *ops; struct device *dev; struct component_match *match; }; struct component { struct list_head node; struct list_head master_node; struct master *master; bool bound; const struct component_ops *ops; struct device *dev; }; static DEFINE_MUTEX(component_mutex); static LIST_HEAD(component_list); static LIST_HEAD(masters); static struct master *__master_find(struct device *dev, const struct component_master_ops *ops) { struct master *m; list_for_each_entry(m, &masters, node) if (m->dev == dev && (!ops || m->ops == ops)) return m; return NULL; } /* Attach an unattached component to a master. */ static void component_attach_master(struct master *master, struct component *c) { c->master = master; list_add_tail(&c->master_node, &master->components); } /* Detach a component from a master. */ static void component_detach_master(struct master *master, struct component *c) { list_del(&c->master_node); c->master = NULL; } /* * Add a component to a master, finding the component via the compare * function and compare data. This is safe to call for duplicate matches * and will not result in the same component being added multiple times. */ int component_master_add_child(struct master *master, int (*compare)(struct device *, void *), void *compare_data) { struct component *c; int ret = -ENXIO; list_for_each_entry(c, &component_list, node) { if (c->master && c->master != master) continue; if (compare(c->dev, compare_data)) { if (!c->master) component_attach_master(master, c); ret = 0; break; } } return ret; } EXPORT_SYMBOL_GPL(component_master_add_child); static int find_components(struct master *master) { struct component_match *match = master->match; size_t i; int ret = 0; if (!match) { /* * Search the list of components, looking for components that * belong to this master, and attach them to the master. */ return master->ops->add_components(master->dev, master); } /* * Scan the array of match functions and attach * any components which are found to this master. */ for (i = 0; i < match->num; i++) { ret = component_master_add_child(master, match->compare[i].fn, match->compare[i].data); if (ret) break; } return ret; } /* Detach all attached components from this master */ static void master_remove_components(struct master *master) { while (!list_empty(&master->components)) { struct component *c = list_first_entry(&master->components, struct component, master_node); WARN_ON(c->master != master); component_detach_master(master, c); } } /* * Try to bring up a master. If component is NULL, we're interested in * this master, otherwise it's a component which must be present to try * and bring up the master. * * Returns 1 for successful bringup, 0 if not ready, or -ve errno. */ static int try_to_bring_up_master(struct master *master, struct component *component) { int ret; if (master->bound) return 0; /* * Search the list of components, looking for components that * belong to this master, and attach them to the master. */ if (find_components(master)) { /* Failed to find all components */ ret = 0; goto out; } if (component && component->master != master) { ret = 0; goto out; } if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) { ret = -ENOMEM; goto out; } /* Found all components */ ret = master->ops->bind(master->dev); if (ret < 0) { devres_release_group(master->dev, NULL); dev_info(master->dev, "master bind failed: %d\n", ret); goto out; } master->bound = true; return 1; out: master_remove_components(master); return ret; } static int try_to_bring_up_masters(struct component *component) { struct master *m; int ret = 0; list_for_each_entry(m, &masters, node) { ret = try_to_bring_up_master(m, component); if (ret != 0) break; } return ret; } static void take_down_master(struct master *master) { if (master->bound) { master->ops->unbind(master->dev); devres_release_group(master->dev, NULL); master->bound = false; } master_remove_components(master); } static size_t component_match_size(size_t num) { return offsetof(struct component_match, compare[num]); } static struct component_match *component_match_realloc(struct device *dev, struct component_match *match, size_t num) { struct component_match *new; if (match && match->alloc == num) return match; new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL); if (!new) return ERR_PTR(-ENOMEM); if (match) { memcpy(new, match, component_match_size(min(match->num, num))); devm_kfree(dev, match); } else { new->num = 0; } new->alloc = num; return new; } /* * Add a component to be matched. * * The match array is first created or extended if necessary. */ void component_match_add(struct device *dev, struct component_match **matchptr, int (*compare)(struct device *, void *), void *compare_data) { struct component_match *match = *matchptr; if (IS_ERR(match)) return; if (!match || match->num == match->alloc) { size_t new_size = match ? match->alloc + 16 : 15; match = component_match_realloc(dev, match, new_size); *matchptr = match; if (IS_ERR(match)) return; } match->compare[match->num].fn = compare; match->compare[match->num].data = compare_data; match->num++; } EXPORT_SYMBOL(component_match_add); int component_master_add_with_match(struct device *dev, const struct component_master_ops *ops, struct component_match *match) { struct master *master; int ret; if (ops->add_components && match) return -EINVAL; if (match) { /* Reallocate the match array for its true size */ match = component_match_realloc(dev, match, match->num); if (IS_ERR(match)) return PTR_ERR(match); } master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return -ENOMEM; master->dev = dev; master->ops = ops; master->match = match; INIT_LIST_HEAD(&master->components); /* Add to the list of available masters. */ mutex_lock(&component_mutex); list_add(&master->node, &masters); ret = try_to_bring_up_master(master, NULL); if (ret < 0) { /* Delete off the list if we weren't successful */ list_del(&master->node); kfree(master); } mutex_unlock(&component_mutex); return ret < 0 ? ret : 0; } EXPORT_SYMBOL_GPL(component_master_add_with_match); int component_master_add(struct device *dev, const struct component_master_ops *ops) { return component_master_add_with_match(dev, ops, NULL); } EXPORT_SYMBOL_GPL(component_master_add); void component_master_del(struct device *dev, const struct component_master_ops *ops) { struct master *master; mutex_lock(&component_mutex); master = __master_find(dev, ops); if (master) { take_down_master(master); list_del(&master->node); kfree(master); } mutex_unlock(&component_mutex); } EXPORT_SYMBOL_GPL(component_master_del); static void component_unbind(struct component *component, struct master *master, void *data) { WARN_ON(!component->bound); component->ops->unbind(component->dev, master->dev, data); component->bound = false; /* Release all resources claimed in the binding of this component */ devres_release_group(component->dev, component); } void component_unbind_all(struct device *master_dev, void *data) { struct master *master; struct component *c; WARN_ON(!mutex_is_locked(&component_mutex)); master = __master_find(master_dev, NULL); if (!master) return; list_for_each_entry_reverse(c, &master->components, master_node) component_unbind(c, master, data); } EXPORT_SYMBOL_GPL(component_unbind_all); static int component_bind(struct component *component, struct master *master, void *data) { int ret; /* * Each component initialises inside its own devres group. * This allows us to roll-back a failed component without * affecting anything else. */ if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) return -ENOMEM; /* * Also open a group for the device itself: this allows us * to release the resources claimed against the sub-device * at the appropriate moment. */ if (!devres_open_group(component->dev, component, GFP_KERNEL)) { devres_release_group(master->dev, NULL); return -ENOMEM; } dev_dbg(master->dev, "binding %s (ops %ps)\n", dev_name(component->dev), component->ops); ret = component->ops->bind(component->dev, master->dev, data); if (!ret) { component->bound = true; /* * Close the component device's group so that resources * allocated in the binding are encapsulated for removal * at unbind. Remove the group on the DRM device as we * can clean those resources up independently. */ devres_close_group(component->dev, NULL); devres_remove_group(master->dev, NULL); dev_info(master->dev, "bound %s (ops %ps)\n", dev_name(component->dev), component->ops); } else { devres_release_group(component->dev, NULL); devres_release_group(master->dev, NULL); dev_err(master->dev, "failed to bind %s (ops %ps): %d\n", dev_name(component->dev), component->ops, ret); } return ret; } int component_bind_all(struct device *master_dev, void *data) { struct master *master; struct component *c; int ret = 0; WARN_ON(!mutex_is_locked(&component_mutex)); master = __master_find(master_dev, NULL); if (!master) return -EINVAL; list_for_each_entry(c, &master->components, master_node) { ret = component_bind(c, master, data); if (ret) break; } if (ret != 0) { list_for_each_entry_continue_reverse(c, &master->components, master_node) component_unbind(c, master, data); } return ret; } EXPORT_SYMBOL_GPL(component_bind_all); int component_add(struct device *dev, const struct component_ops *ops) { struct component *component; int ret; component = kzalloc(sizeof(*component), GFP_KERNEL); if (!component) return -ENOMEM; component->ops = ops; component->dev = dev; dev_dbg(dev, "adding component (ops %ps)\n", ops); mutex_lock(&component_mutex); list_add_tail(&component->node, &component_list); ret = try_to_bring_up_masters(component); if (ret < 0) { list_del(&component->node); kfree(component); } mutex_unlock(&component_mutex); return ret < 0 ? ret : 0; } EXPORT_SYMBOL_GPL(component_add); void component_del(struct device *dev, const struct component_ops *ops) { struct component *c, *component = NULL; mutex_lock(&component_mutex); list_for_each_entry(c, &component_list, node) if (c->dev == dev && c->ops == ops) { list_del(&c->node); component = c; break; }