[PATCH v2 08/12] drm/client: Add client callbacks

Noralf Trønnes noralf at tronnes.org
Mon Jun 18 14:17:35 UTC 2018


Add client callbacks and hook them up.
Add a list of clients per drm_device.

Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---

Changes since version 1:
- Remove unused functions
- Change name drm_client_funcs.lastclose -> .restore
- Change name drm_client_funcs.remove -> .unregister
- Rework unregister code


 drivers/gpu/drm/drm_client.c        | 97 +++++++++++++++++++++++++++++++++++--
 drivers/gpu/drm/drm_drv.c           |  7 +++
 drivers/gpu/drm/drm_fb_cma_helper.c |  2 +-
 drivers/gpu/drm/drm_file.c          |  3 ++
 drivers/gpu/drm/drm_probe_helper.c  |  3 ++
 include/drm/drm_client.h            | 69 +++++++++++++++++++++++++-
 include/drm/drm_device.h            | 14 ++++++
 7 files changed, 190 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 98dda40f5416..f1dc04d641cc 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -74,6 +74,7 @@ EXPORT_SYMBOL(drm_client_close);
  * @dev: DRM device
  * @client: DRM client
  * @name: Client name
+ * @funcs: DRM client functions (optional)
  *
  * Use drm_client_put() to free the client.
  *
@@ -81,8 +82,9 @@ EXPORT_SYMBOL(drm_client_close);
  * Zero on success or negative error code on failure.
  */
 int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
-		   const char *name)
+		   const char *name, const struct drm_client_funcs *funcs)
 {
+	bool registered;
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET) ||
@@ -91,12 +93,23 @@ int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
 
 	client->dev = dev;
 	client->name = name;
+	client->funcs = funcs;
 	kref_init(&client->ref);
 
 	ret = drm_client_open(client);
 	if (ret)
 		return ret;
 
+	mutex_lock(&dev->clientlist_mutex);
+	registered = dev->registered;
+	if (registered)
+		list_add(&client->list, &dev->clientlist);
+	mutex_unlock(&dev->clientlist_mutex);
+	if (!registered) {
+		drm_client_close(client);
+		return -ENODEV;
+	}
+
 	drm_dev_get(dev);
 
 	return 0;
@@ -110,8 +123,17 @@ static void drm_client_release(struct kref *ref)
 
 	DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name);
 
-	drm_client_close(client);
-	kfree(client);
+	mutex_lock(&dev->clientlist_mutex);
+	if (!list_empty(&client->list))
+		list_del(&client->list);
+	mutex_unlock(&dev->clientlist_mutex);
+
+	if (client->funcs && client->funcs->release) {
+		client->funcs->release(client);
+	} else {
+		drm_client_close(client);
+		kfree(client);
+	}
 
 	drm_dev_put(dev);
 }
@@ -145,6 +167,75 @@ void drm_client_put(struct drm_client_dev *client)
 }
 EXPORT_SYMBOL(drm_client_put);
 
+void drm_client_dev_unregister(struct drm_device *dev)
+{
+	struct drm_client_dev *client, *iter;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return;
+
+	do {
+		client = NULL;
+		mutex_lock(&dev->clientlist_mutex);
+		list_for_each_entry(iter, &dev->clientlist, list) {
+			list_del_init(&iter->list);
+			if (iter->funcs && iter->funcs->unregister) {
+				/* Make sure a release has not begun */
+				if (kref_get_unless_zero(&iter->ref)) {
+					client = iter;
+					break;
+				}
+			}
+		}
+		mutex_unlock(&dev->clientlist_mutex);
+		if (client) {
+			client->funcs->unregister(client);
+			drm_client_put(client);
+		}
+	} while (client);
+}
+
+void drm_client_dev_hotplug(struct drm_device *dev)
+{
+	struct drm_client_dev *client;
+	int ret;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list) {
+		if (!client->funcs || !client->funcs->hotplug)
+			continue;
+
+		ret = client->funcs->hotplug(client);
+		DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+EXPORT_SYMBOL(drm_client_dev_hotplug);
+
+void drm_client_dev_restore(struct drm_device *dev)
+{
+	struct drm_client_dev *client;
+	int ret;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list) {
+		if (!client->funcs || !client->funcs->restore)
+			continue;
+
+		ret = client->funcs->restore(client);
+		DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
+		if (!ret) /* The first one to return zero gets the privilege to restore */
+			break;
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+
 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
 {
 	struct drm_device *dev;
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 67ac793a7108..00172a3da62c 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/srcu.h>
 
+#include <drm/drm_client.h>
 #include <drm/drm_drv.h>
 #include <drm/drmP.h>
 
@@ -506,6 +507,7 @@ int drm_dev_init(struct drm_device *dev,
 
 	INIT_LIST_HEAD(&dev->filelist);
 	INIT_LIST_HEAD(&dev->filelist_internal);
+	INIT_LIST_HEAD(&dev->clientlist);
 	INIT_LIST_HEAD(&dev->ctxlist);
 	INIT_LIST_HEAD(&dev->vmalist);
 	INIT_LIST_HEAD(&dev->maplist);
@@ -515,6 +517,7 @@ int drm_dev_init(struct drm_device *dev,
 	spin_lock_init(&dev->event_lock);
 	mutex_init(&dev->struct_mutex);
 	mutex_init(&dev->filelist_mutex);
+	mutex_init(&dev->clientlist_mutex);
 	mutex_init(&dev->ctxlist_mutex);
 	mutex_init(&dev->master_mutex);
 
@@ -570,6 +573,7 @@ int drm_dev_init(struct drm_device *dev,
 err_free:
 	mutex_destroy(&dev->master_mutex);
 	mutex_destroy(&dev->ctxlist_mutex);
+	mutex_destroy(&dev->clientlist_mutex);
 	mutex_destroy(&dev->filelist_mutex);
 	mutex_destroy(&dev->struct_mutex);
 	return ret;
@@ -604,6 +608,7 @@ void drm_dev_fini(struct drm_device *dev)
 
 	mutex_destroy(&dev->master_mutex);
 	mutex_destroy(&dev->ctxlist_mutex);
+	mutex_destroy(&dev->clientlist_mutex);
 	mutex_destroy(&dev->filelist_mutex);
 	mutex_destroy(&dev->struct_mutex);
 	kfree(dev->unique);
@@ -859,6 +864,8 @@ void drm_dev_unregister(struct drm_device *dev)
 
 	dev->registered = false;
 
+	drm_client_dev_unregister(dev);
+
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_modeset_unregister_all(dev);
 
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index dbd1933160d1..31831a7a6a99 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -182,7 +182,7 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
 
 	fb_helper = &fbdev_cma->fb_helper;
 
-	ret = drm_client_new(dev, &fb_helper->client, "fbdev");
+	ret = drm_client_new(dev, &fb_helper->client, "fbdev", NULL);
 	if (ret)
 		goto err_free;
 
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 55505378df47..06e409007495 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -35,6 +35,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 
+#include <drm/drm_client.h>
 #include <drm/drm_file.h>
 #include <drm/drmP.h>
 
@@ -443,6 +444,8 @@ void drm_lastclose(struct drm_device * dev)
 
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 		drm_legacy_dev_reinit(dev);
+
+	drm_client_dev_restore(dev);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 527743394150..26be57e28a9d 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -33,6 +33,7 @@
 #include <linux/moduleparam.h>
 
 #include <drm/drmP.h>
+#include <drm/drm_client.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_crtc_helper.h>
@@ -563,6 +564,8 @@ void drm_kms_helper_hotplug_event(struct drm_device *dev)
 	drm_sysfs_hotplug_event(dev);
 	if (dev->mode_config.funcs->output_poll_changed)
 		dev->mode_config.funcs->output_poll_changed(dev);
+
+	drm_client_dev_hotplug(dev);
 }
 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 12ac2615b17d..80fe21c86f69 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -6,11 +6,61 @@
 #include <linux/kref.h>
 #include <linux/types.h>
 
+struct drm_client_dev;
 struct drm_device;
 struct drm_framebuffer;
 struct drm_gem_object;
 struct drm_minor;
 
+/**
+ * struct drm_client_funcs - DRM client callbacks
+ */
+struct drm_client_funcs {
+	/**
+	 * @release:
+	 *
+	 * Called when the reference count is dropped to zero. Users of this
+	 * callback is responsible for calling drm_client_close() and freeing
+	 * the client structure.
+	 *
+	 * This callback is optional.
+	 */
+	void (*release)(struct drm_client_dev *client);
+
+	/**
+	 * @unregister:
+	 *
+	 * Called when &drm_device is unregistered. The client should respond by
+	 * releasing it's resources using drm_client_put(). If it can't do so
+	 * due to resoruces being tied up, like fbdev with open file handles,
+	 * it should release it's resources as soon as possible.
+	 *
+	 * This callback is optional.
+	 */
+	void (*unregister)(struct drm_client_dev *client);
+
+	/**
+	 * @restore:
+	 *
+	 * Called on drm_lastclose(). The first client instance in the list that
+	 * returns zero gets the privilege to restore and no more clients are
+	 * called. This callback is not called after @unregister has been called.
+	 *
+	 * This callback is optional.
+	 */
+	int (*restore)(struct drm_client_dev *client);
+
+	/**
+	 * @hotplug:
+	 *
+	 * Called on drm_kms_helper_hotplug_event().
+	 * This callback is not called after @unregister has been called.
+	 *
+	 * This callback is optional.
+	 */
+	int (*hotplug)(struct drm_client_dev *client);
+};
+
 /**
  * struct drm_client_dev - DRM client instance
  */
@@ -33,6 +83,19 @@ struct drm_client_dev {
 	 */
 	struct kref ref;
 
+	/**
+	 * @list:
+	 *
+	 * List of all clients of a DRM device, linked into
+	 * &drm_device.clientlist. Protected by &drm_device.clientlist_mutex.
+	 */
+	struct list_head list;
+
+	/**
+	 * @funcs: DRM client functions (optional)
+	 */
+	const struct drm_client_funcs *funcs;
+
 	/**
 	 * @file: DRM file
 	 */
@@ -41,10 +104,14 @@ struct drm_client_dev {
 
 void drm_client_close(struct drm_client_dev *client);
 int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
-		   const char *name);
+		   const char *name, const struct drm_client_funcs *funcs);
 void drm_client_get(struct drm_client_dev *client);
 void drm_client_put(struct drm_client_dev *client);
 
+void drm_client_dev_unregister(struct drm_device *dev);
+void drm_client_dev_hotplug(struct drm_device *dev);
+void drm_client_dev_restore(struct drm_device *dev);
+
 /**
  * struct drm_client_buffer - DRM client buffer
  */
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 9e29976d4e98..f9c6e0e3aec7 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -81,6 +81,20 @@ struct drm_device {
 	 */
 	struct list_head filelist_internal;
 
+	/**
+	 * @clientlist_mutex:
+	 *
+	 * Protects @clientlist access.
+	 */
+	struct mutex clientlist_mutex;
+
+	/**
+	 * @clientlist:
+	 *
+	 * List of in-kernel clients. Protected by @clientlist_mutex.
+	 */
+	struct list_head clientlist;
+
 	/** \name Memory management */
 	/*@{ */
 	struct list_head maplist;	/**< Linked list of regions */
-- 
2.15.1



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