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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Componentized device handling.
  */
 #include <linux/component.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/debugfs.h>
 
 /**
  * DOC: overview
  *
  * The component helper allows drivers to collect a pile of sub-devices,
  * including their bound drivers, into an aggregate driver. Various subsystems
  * already provide functions to get hold of such components, e.g.
  * of_clk_get_by_name(). The component helper can be used when such a
  * subsystem-specific way to find a device is not available: The component
  * helper fills the niche of aggregate drivers for specific hardware, where
  * further standardization into a subsystem would not be practical. The common
  * example is when a logical device (e.g. a DRM display driver) is spread around
  * the SoC on various components (scanout engines, blending blocks, transcoders
  * for various outputs and so on).
  *
  * The component helper also doesn't solve runtime dependencies, e.g. for system
  * suspend and resume operations. See also :ref:`device links<device_link>`.
  *
  * Components are registered using component_add() and unregistered with
  * component_del(), usually from the driver's probe and disconnect functions.
  *
  * Aggregate drivers first assemble a component match list of what they need
  * using component_match_add(). This is then registered as an aggregate driver
  * using component_master_add_with_match(), and unregistered using
  * component_master_del().
  */
 
 struct component;
 
 struct component_match_array {
     void *data;
     int (*compare)(struct device *, void *);
     int (*compare_typed)(struct device *, int, void *);
     void (*release)(struct device *, void *);
     struct component *component;
     bool duplicate;
 };
 
 struct component_match {
     size_t alloc;
     size_t num;
     struct component_match_array *compare;
 };
 
 struct aggregate_device {
     struct list_head node;
     bool bound;
 
     const struct component_master_ops *ops;
     struct device *parent;
     struct component_match *match;
 };
 
 struct component {
     struct list_head node;
     struct aggregate_device *adev;
     bool bound;
 
     const struct component_ops *ops;
     int subcomponent;
     struct device *dev;
 };
 
 static DEFINE_MUTEX(component_mutex);
 static LIST_HEAD(component_list);
 static LIST_HEAD(aggregate_devices);
 
 #ifdef CONFIG_DEBUG_FS
 
 static struct dentry *component_debugfs_dir;
 
 static int component_devices_show(struct seq_file *s, void *data)
 {
     struct aggregate_device *m = s->private;
     struct component_match *match = m->match;
     size_t i;
 
     mutex_lock(&component_mutex);
     seq_printf(s, "%-40s %20s\n", "aggregate_device name", "status");
     seq_puts(s, "-------------------------------------------------------------\n");
     seq_printf(s, "%-40s %20s\n\n",
            dev_name(m->parent), m->bound ? "bound" : "not bound");
 
     seq_printf(s, "%-40s %20s\n", "device name", "status");
     seq_puts(s, "-------------------------------------------------------------\n");
     for (i = 0; i < match->num; i++) {
         struct component *component = match->compare[i].component;
 
         seq_printf(s, "%-40s %20s\n",
                component ? dev_name(component->dev) : "(unknown)",
                component ? (component->bound ? "bound" : "not bound") : "not registered");
     }
     mutex_unlock(&component_mutex);
 
     return 0;
 }
 
 DEFINE_SHOW_ATTRIBUTE(component_devices);
 
 static int __init component_debug_init(void)
 {
     component_debugfs_dir = debugfs_create_dir("device_component", NULL);
 
     return 0;
 }
 
 core_initcall(component_debug_init);
 
 static void component_debugfs_add(struct aggregate_device *m)
 {
     debugfs_create_file(dev_name(m->parent), 0444, component_debugfs_dir, m,
                 &component_devices_fops);
 }
 
 static void component_debugfs_del(struct aggregate_device *m)
 {
     debugfs_remove(debugfs_lookup(dev_name(m->parent), component_debugfs_dir));
 }
 
 #else
 
 static void component_debugfs_add(struct aggregate_device *m)
 { }
 
 static void component_debugfs_del(struct aggregate_device *m)
 { }
 
 #endif
 
 static struct aggregate_device *__aggregate_find(struct device *parent,
     const struct component_master_ops *ops)
 {
     struct aggregate_device *m;
 
     list_for_each_entry(m, &aggregate_devices, node)
         if (m->parent == parent && (!ops || m->ops == ops))
             return m;
 
     return NULL;
 }
 
 static struct component *find_component(struct aggregate_device *adev,
     struct component_match_array *mc)
 {
     struct component *c;
 
     list_for_each_entry(c, &component_list, node) {
         if (c->adev && c->adev != adev)
             continue;
 
         if (mc->compare && mc->compare(c->dev, mc->data))
             return c;
 
         if (mc->compare_typed &&
             mc->compare_typed(c->dev, c->subcomponent, mc->data))
             return c;
     }
 
     return NULL;
 }
 
 static int find_components(struct aggregate_device *adev)
 {
     struct component_match *match = adev->match;
     size_t i;
     int ret = 0;
 
     /*
      * Scan the array of match functions and attach
      * any components which are found to this adev.
      */
     for (i = 0; i < match->num; i++) {
         struct component_match_array *mc = &match->compare[i];
         struct component *c;
 
         dev_dbg(adev->parent, "Looking for component %zu\n", i);
 
         if (match->compare[i].component)
             continue;
 
         c = find_component(adev, mc);
         if (!c) {
             ret = -ENXIO;
             break;
         }
 
         dev_dbg(adev->parent, "found component %s, duplicate %u\n",
             dev_name(c->dev), !!c->adev);
 
         /* Attach this component to the adev */
         match->compare[i].duplicate = !!c->adev;
         match->compare[i].component = c;
         c->adev = adev;
     }
     return ret;
 }
 
 /* Detach component from associated aggregate_device */
 static void remove_component(struct aggregate_device *adev, struct component *c)
 {
     size_t i;
 
     /* Detach the component from this adev. */
     for (i = 0; i < adev->match->num; i++)
         if (adev->match->compare[i].component == c)
             adev->match->compare[i].component = NULL;
 }
 
 /*
  * Try to bring up an aggregate device.  If component is NULL, we're interested
  * in this aggregate device, otherwise it's a component which must be present
  * to try and bring up the aggregate device.
  *
  * Returns 1 for successful bringup, 0 if not ready, or -ve errno.
  */
 static int try_to_bring_up_aggregate_device(struct aggregate_device *adev,
     struct component *component)
 {
     int ret;
 
     dev_dbg(adev->parent, "trying to bring up adev\n");
 
     if (find_components(adev)) {
         dev_dbg(adev->parent, "master has incomplete components\n");
         return 0;
     }
 
     if (component && component->adev != adev) {
         dev_dbg(adev->parent, "master is not for this component (%s)\n",
             dev_name(component->dev));
         return 0;
     }
 
     if (!devres_open_group(adev->parent, adev, GFP_KERNEL))
         return -ENOMEM;
 
     /* Found all components */
     ret = adev->ops->bind(adev->parent);
     if (ret < 0) {
         devres_release_group(adev->parent, NULL);
         if (ret != -EPROBE_DEFER)
             dev_info(adev->parent, "adev bind failed: %d\n", ret);
         return ret;
     }
 
     devres_close_group(adev->parent, NULL);
     adev->bound = true;
     return 1;
 }
 
 static int try_to_bring_up_masters(struct component *component)
 {
     struct aggregate_device *adev;
     int ret = 0;
 
     list_for_each_entry(adev, &aggregate_devices, node) {
         if (!adev->bound) {
             ret = try_to_bring_up_aggregate_device(adev, component);
             if (ret != 0)
                 break;
         }
     }
 
     return ret;
 }
 
 static void take_down_aggregate_device(struct aggregate_device *adev)
 {
     if (adev->bound) {
         adev->ops->unbind(adev->parent);
         devres_release_group(adev->parent, adev);
         adev->bound = false;
     }
 }
 
 /**
  * component_compare_of - A common component compare function for of_node
  * @dev: component device
  * @data: @compare_data from component_match_add_release()
  *
  * A common compare function when compare_data is device of_node. e.g.
  * component_match_add_release(masterdev, &match, component_release_of,
  * component_compare_of, component_dev_of_node)
  */
 int component_compare_of(struct device *dev, void *data)
 {
     return device_match_of_node(dev, data);
 }
 EXPORT_SYMBOL_GPL(component_compare_of);
 
 /**
  * component_release_of - A common component release function for of_node
  * @dev: component device
  * @data: @compare_data from component_match_add_release()
  *
  * About the example, Please see component_compare_of().
  */
 void component_release_of(struct device *dev, void *data)
 {
     of_node_put(data);
 }
 EXPORT_SYMBOL_GPL(component_release_of);
 
 /**
  * component_compare_dev - A common component compare function for dev
  * @dev: component device
  * @data: @compare_data from component_match_add_release()
  *
  * A common compare function when compare_data is struce device. e.g.
  * component_match_add(masterdev, &match, component_compare_dev, component_dev)
  */
 int component_compare_dev(struct device *dev, void *data)
 {
     return dev == data;
 }
 EXPORT_SYMBOL_GPL(component_compare_dev);
 
 /**
  * component_compare_dev_name - A common component compare function for device name
  * @dev: component device
  * @data: @compare_data from component_match_add_release()
  *
  * A common compare function when compare_data is device name string. e.g.
  * component_match_add(masterdev, &match, component_compare_dev_name,
  * "component_dev_name")
  */
 int component_compare_dev_name(struct device *dev, void *data)
 {
     return device_match_name(dev, data);
 }
 EXPORT_SYMBOL_GPL(component_compare_dev_name);
 
 static void devm_component_match_release(struct device *parent, void *res)
 {
     struct component_match *match = res;
     unsigned int i;
 
     for (i = 0; i < match->num; i++) {
         struct component_match_array *mc = &match->compare[i];
 
         if (mc->release)
             mc->release(parent, mc->data);
     }
 
     kfree(match->compare);
 }
 
 static int component_match_realloc(struct component_match *match, size_t num)
 {
     struct component_match_array *new;
 
     if (match->alloc == num)
         return 0;
 
     new = kmalloc_array(num, sizeof(*new), GFP_KERNEL);
     if (!new)
         return -ENOMEM;
 
     if (match->compare) {
         memcpy(new, match->compare, sizeof(*new) *
                         min(match->num, num));
         kfree(match->compare);
     }
     match->compare = new;
     match->alloc = num;
 
     return 0;
 }
 
 static void __component_match_add(struct device *parent,
     struct component_match **matchptr,
     void (*release)(struct device *, void *),
     int (*compare)(struct device *, void *),
     int (*compare_typed)(struct device *, int, void *),
     void *compare_data)
 {
     struct component_match *match = *matchptr;
 
     if (IS_ERR(match))
         return;
 
     if (!match) {
         match = devres_alloc(devm_component_match_release,
                      sizeof(*match), GFP_KERNEL);
         if (!match) {
             *matchptr = ERR_PTR(-ENOMEM);
             return;
         }
 
         devres_add(parent, match);
 
         *matchptr = match;
     }
 
     if (match->num == match->alloc) {
         size_t new_size = match->alloc + 16;
         int ret;
 
         ret = component_match_realloc(match, new_size);
         if (ret) {
             *matchptr = ERR_PTR(ret);
             return;
         }
     }
 
     match->compare[match->num].compare = compare;
     match->compare[match->num].compare_typed = compare_typed;
     match->compare[match->num].release = release;
     match->compare[match->num].data = compare_data;
     match->compare[match->num].component = NULL;
     match->num++;
 }
 
 /**
  * component_match_add_release - add a component match entry with release callback
  * @parent: parent device of the aggregate driver
  * @matchptr: pointer to the list of component matches
  * @release: release function for @compare_data
  * @compare: compare function to match against all components
  * @compare_data: opaque pointer passed to the @compare function
  *
  * Adds a new component match to the list stored in @matchptr, which the
  * aggregate driver needs to function. The list of component matches pointed to
  * by @matchptr must be initialized to NULL before adding the first match. This
  * only matches against components added with component_add().
  *
  * The allocated match list in @matchptr is automatically released using devm
  * actions, where upon @release will be called to free any references held by
  * @compare_data, e.g. when @compare_data is a &device_node that must be
  * released with of_node_put().
  *
  * See also component_match_add() and component_match_add_typed().
  */
 void component_match_add_release(struct device *parent,
     struct component_match **matchptr,
     void (*release)(struct device *, void *),
     int (*compare)(struct device *, void *), void *compare_data)
 {
     __component_match_add(parent, matchptr, release, compare, NULL,
                   compare_data);
 }
 EXPORT_SYMBOL(component_match_add_release);
 
 /**
  * component_match_add_typed - add a component match entry for a typed component
  * @parent: parent device of the aggregate driver
  * @matchptr: pointer to the list of component matches
  * @compare_typed: compare function to match against all typed components
  * @compare_data: opaque pointer passed to the @compare function
  *
  * Adds a new component match to the list stored in @matchptr, which the
  * aggregate driver needs to function. The list of component matches pointed to
  * by @matchptr must be initialized to NULL before adding the first match. This
  * only matches against components added with component_add_typed().
  *
  * The allocated match list in @matchptr is automatically released using devm
  * actions.
  *
  * See also component_match_add_release() and component_match_add_typed().
  */
 void component_match_add_typed(struct device *parent,
     struct component_match **matchptr,
     int (*compare_typed)(struct device *, int, void *), void *compare_data)
 {
     __component_match_add(parent, matchptr, NULL, NULL, compare_typed,
                   compare_data);
 }
 EXPORT_SYMBOL(component_match_add_typed);
 
 static void free_aggregate_device(struct aggregate_device *adev)
 {
     struct component_match *match = adev->match;
     int i;
 
     component_debugfs_del(adev);
     list_del(&adev->node);
 
     if (match) {
         for (i = 0; i < match->num; i++) {
             struct component *c = match->compare[i].component;
             if (c)
                 c->adev = NULL;
         }
     }
 
     kfree(adev);
 }
 
 /**
  * component_master_add_with_match - register an aggregate driver
  * @parent: parent device of the aggregate driver
  * @ops: callbacks for the aggregate driver
  * @match: component match list for the aggregate driver
  *
  * Registers a new aggregate driver consisting of the components added to @match
  * by calling one of the component_match_add() functions. Once all components in
  * @match are available, it will be assembled by calling
  * &component_master_ops.bind from @ops. Must be unregistered by calling
  * component_master_del().
  */
 int component_master_add_with_match(struct device *parent,
     const struct component_master_ops *ops,
     struct component_match *match)
 {
     struct aggregate_device *adev;
     int ret;
 
     /* Reallocate the match array for its true size */
     ret = component_match_realloc(match, match->num);
     if (ret)
         return ret;
 
     adev = kzalloc(sizeof(*adev), GFP_KERNEL);
     if (!adev)
         return -ENOMEM;
 
     adev->parent = parent;
     adev->ops = ops;
     adev->match = match;
 
     component_debugfs_add(adev);
     /* Add to the list of available aggregate devices. */
     mutex_lock(&component_mutex);
     list_add(&adev->node, &aggregate_devices);
 
     ret = try_to_bring_up_aggregate_device(adev, NULL);
 
     if (ret < 0)
         free_aggregate_device(adev);
 
     mutex_unlock(&component_mutex);
 
     return ret < 0 ? ret : 0;
 }
 EXPORT_SYMBOL_GPL(component_master_add_with_match);
 
 /**
  * component_master_del - unregister an aggregate driver
  * @parent: parent device of the aggregate driver
  * @ops: callbacks for the aggregate driver
  *
  * Unregisters an aggregate driver registered with
  * component_master_add_with_match(). If necessary the aggregate driver is first
  * disassembled by calling &component_master_ops.unbind from @ops.
  */
 void component_master_del(struct device *parent,
     const struct component_master_ops *ops)
 {
     struct aggregate_device *adev;
 
     mutex_lock(&component_mutex);
     adev = __aggregate_find(parent, ops);
     if (adev) {
         take_down_aggregate_device(adev);
         free_aggregate_device(adev);
     }
     mutex_unlock(&component_mutex);
 }
 EXPORT_SYMBOL_GPL(component_master_del);
 
 static void component_unbind(struct component *component,
     struct aggregate_device *adev, void *data)
 {
     WARN_ON(!component->bound);
 
     if (component->ops && component->ops->unbind)
         component->ops->unbind(component->dev, adev->parent, data);
     component->bound = false;
 
     /* Release all resources claimed in the binding of this component */
     devres_release_group(component->dev, component);
 }
 
 /**
  * component_unbind_all - unbind all components of an aggregate driver
  * @parent: parent device of the aggregate driver
  * @data: opaque pointer, passed to all components
  *
  * Unbinds all components of the aggregate device by passing @data to their
  * &component_ops.unbind functions. Should be called from
  * &component_master_ops.unbind.
  */
 void component_unbind_all(struct device *parent, void *data)
 {
     struct aggregate_device *adev;
     struct component *c;
     size_t i;
 
     WARN_ON(!mutex_is_locked(&component_mutex));
 
     adev = __aggregate_find(parent, NULL);
     if (!adev)
         return;
 
     /* Unbind components in reverse order */
     for (i = adev->match->num; i--; )
         if (!adev->match->compare[i].duplicate) {
             c = adev->match->compare[i].component;
             component_unbind(c, adev, data);
         }
 }
 EXPORT_SYMBOL_GPL(component_unbind_all);
 
 static int component_bind(struct component *component, struct aggregate_device *adev,
     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(adev->parent, 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(adev->parent, NULL);
         return -ENOMEM;
     }
 
     dev_dbg(adev->parent, "binding %s (ops %ps)\n",
         dev_name(component->dev), component->ops);
 
     ret = component->ops->bind(component->dev, adev->parent, 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(adev->parent, NULL);
 
         dev_info(adev->parent, "bound %s (ops %ps)\n",
              dev_name(component->dev), component->ops);
     } else {
         devres_release_group(component->dev, NULL);
         devres_release_group(adev->parent, NULL);
 
         if (ret != -EPROBE_DEFER)
             dev_err(adev->parent, "failed to bind %s (ops %ps): %d\n",
                 dev_name(component->dev), component->ops, ret);
     }
 
     return ret;
 }
 
 /**
  * component_bind_all - bind all components of an aggregate driver
  * @parent: parent device of the aggregate driver
  * @data: opaque pointer, passed to all components
  *
  * Binds all components of the aggregate @dev by passing @data to their
  * &component_ops.bind functions. Should be called from
  * &component_master_ops.bind.
  */
 int component_bind_all(struct device *parent, void *data)
 {
     struct aggregate_device *adev;
     struct component *c;
     size_t i;
     int ret = 0;
 
     WARN_ON(!mutex_is_locked(&component_mutex));
 
     adev = __aggregate_find(parent, NULL);
     if (!adev)
         return -EINVAL;
 
     /* Bind components in match order */
     for (i = 0; i < adev->match->num; i++)
         if (!adev->match->compare[i].duplicate) {
             c = adev->match->compare[i].component;
             ret = component_bind(c, adev, data);
             if (ret)
                 break;
         }
 
     if (ret != 0) {
         for (; i > 0; i--)
             if (!adev->match->compare[i - 1].duplicate) {
                 c = adev->match->compare[i - 1].component;
                 component_unbind(c, adev, data);
             }
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(component_bind_all);
 
 static int __component_add(struct device *dev, const struct component_ops *ops,
     int subcomponent)
 {
     struct component *component;
     int ret;
 
     component = kzalloc(sizeof(*component), GFP_KERNEL);
     if (!component)
         return -ENOMEM;
 
     component->ops = ops;
     component->dev = dev;
     component->subcomponent = subcomponent;
 
     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) {
         if (component->adev)
             remove_component(component->adev, component);
         list_del(&component->node);
 
         kfree(component);
     }
     mutex_unlock(&component_mutex);
 
     return ret < 0 ? ret : 0;
 }
 
 /**
  * component_add_typed - register a component
  * @dev: component device
  * @ops: component callbacks
  * @subcomponent: nonzero identifier for subcomponents
  *
  * Register a new component for @dev. Functions in @ops will be call when the
  * aggregate driver is ready to bind the overall driver by calling
  * component_bind_all(). See also &struct component_ops.
  *
  * @subcomponent must be nonzero and is used to differentiate between multiple
  * components registerd on the same device @dev. These components are match
  * using component_match_add_typed().
  *
  * The component needs to be unregistered at driver unload/disconnect by
  * calling component_del().
  *
  * See also component_add().
  */
 int component_add_typed(struct device *dev, const struct component_ops *ops,
     int subcomponent)
 {
     if (WARN_ON(subcomponent == 0))
         return -EINVAL;
 
     return __component_add(dev, ops, subcomponent);
 }
 EXPORT_SYMBOL_GPL(component_add_typed);
 
 /**
  * component_add - register a component
  * @dev: component device
  * @ops: component callbacks
  *
  * Register a new component for @dev. Functions in @ops will be called when the
  * aggregate driver is ready to bind the overall driver by calling
  * component_bind_all(). See also &struct component_ops.
  *
  * The component needs to be unregistered at driver unload/disconnect by
  * calling component_del().
  *
  * See also component_add_typed() for a variant that allows multipled different
  * components on the same device.
  */
 int component_add(struct device *dev, const struct component_ops *ops)
 {
     return __component_add(dev, ops, 0);
 }
 EXPORT_SYMBOL_GPL(component_add);
 
 /**
  * component_del - unregister a component
  * @dev: component device
  * @ops: component callbacks
  *
  * Unregister a component added with component_add(). If the component is bound
  * into an aggregate driver, this will force the entire aggregate driver, including
  * all its components, to be unbound.
  */
 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;
         }
 
     if (component && component->adev) {
         take_down_aggregate_device(component->adev);
         remove_component(component->adev, component);
     }
 
     mutex_unlock(&component_mutex);
 
     WARN_ON(!component);
     kfree(component);
 }
 EXPORT_SYMBOL_GPL(component_del);

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