[PATCH 8/9] drm/client: Add client callbacks

From: "Noralf Trønnes" <noralf@tronnes.org>
To: dri-devel@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org, laurent.pinchart@ideasonboard.com
Subject: [PATCH 8/9] drm/client: Add client callbacks
Date: Wed, 23 May 2018 16:34:10 +0200	[thread overview]
Message-ID: <20180523143411.64070-9-noralf@tronnes.org> (raw)
In-Reply-To: <20180523143411.64070-1-noralf@tronnes.org>

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

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 drivers/gpu/drm/drm_client.c        | 246 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/drm_debugfs.c       |   7 +
 drivers/gpu/drm/drm_drv.c           |   8 ++
 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            |  65 +++++++++-
 include/drm/drm_device.h            |  14 ++
 8 files changed, 345 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 0919aea7dddd..c495fcee2058 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -66,11 +66,13 @@ static void drm_client_free_file(struct drm_client_dev *client)
 /**
  * drm_client_new - Create a DRM client
  * @dev: DRM device
+ * @funcs: DRM client functions
  *
  * Returns:
  * Pointer to a client or an error pointer on failure.
  */
-struct drm_client_dev *drm_client_new(struct drm_device *dev)
+struct drm_client_dev *
+drm_client_new(struct drm_device *dev, const struct drm_client_funcs *funcs)
 {
 	struct drm_client_dev *client;
 	int ret;
@@ -84,6 +86,7 @@ struct drm_client_dev *drm_client_new(struct drm_device *dev)
 		return ERR_PTR(-ENOMEM);
 
 	client->dev = dev;
+	client->funcs = funcs;
 
 	ret = drm_client_alloc_file(client);
 	if (ret) {
@@ -91,21 +94,231 @@ struct drm_client_dev *drm_client_new(struct drm_device *dev)
 		return ERR_PTR(ret);
 	}
 
+	/*
+	 * TODO:
+	 * Temporary hack until all CMA drivers have been moved over to using
+	 * drm_fbdev_generic_setup().
+	 */
+	if (!funcs)
+		return client;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_add(&client->list, &dev->clientlist);
+	mutex_unlock(&dev->clientlist_mutex);
+
 	return client;
 }
 EXPORT_SYMBOL(drm_client_new);
 
+/**
+ * drm_client_new_from_id - Create a DRM client from a minor id
+ * @minor_id: DRM minor id
+ * @funcs: DRM client functions
+ *
+ * Returns:
+ * Pointer to a client or an error pointer on failure.
+ */
+struct drm_client_dev *
+drm_client_new_from_id(unsigned int minor_id, const struct drm_client_funcs *funcs)
+{
+	struct drm_client_dev *client;
+	struct drm_minor *minor;
+
+	minor = drm_minor_acquire(minor_id);
+	if (IS_ERR(minor))
+		return ERR_CAST(minor);
+
+	client = drm_client_new(minor->dev, funcs);
+
+	drm_minor_release(minor);
+
+	return client;
+}
+EXPORT_SYMBOL(drm_client_new_from_id);
+
 /**
  * drm_client_free - Free DRM client resources
  * @client: DRM client
+ *
+ * This is called automatically on client removal unless the client returns
+ * non-zero in the &drm_client_funcs->remove callback. The fbdev client does
+ * this when it can't close &drm_file because userspace has an open fd.
+ *
+ * Note:
+ * If the client can't release it's resources on remove, it needs to hold a
+ * reference on the driver module to prevent the code from going away.
  */
 void drm_client_free(struct drm_client_dev *client)
 {
+	DRM_DEV_DEBUG_KMS(client->dev->dev, "\n");
 	drm_client_free_file(client);
 	kfree(client);
 }
 EXPORT_SYMBOL(drm_client_free);
 
+static void drm_client_remove_locked(struct drm_client_dev *client)
+{
+	list_del(&client->list);
+
+	if (!client->funcs->remove || !client->funcs->remove(client))
+		drm_client_free(client);
+}
+
+static void drm_client_remove_safe(struct drm_device *dev,
+				   struct drm_client_dev *client)
+{
+	struct drm_client_dev *iter;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(iter, &dev->clientlist, list) {
+		if (iter == client) {
+			drm_client_remove_locked(client);
+			break;
+		}
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+
+/**
+ * drm_client_remove - Remove client
+ * @client: Client
+ *
+ * Remove the DRM client.
+ */
+void drm_client_remove(struct drm_client_dev *client)
+{
+	struct drm_device *dev;
+
+	if (!client)
+		return;
+
+	dev = client->dev;
+	/* Hold a reference since the client might drop the last one */
+	drm_dev_get(dev);
+	drm_client_remove_safe(dev, client);
+	drm_dev_put(dev);
+}
+EXPORT_SYMBOL(drm_client_remove);
+
+struct drm_client_remove_defer {
+	struct list_head list;
+	struct drm_device *dev;
+	struct drm_client_dev *client;
+};
+
+static LIST_HEAD(drm_client_remove_defer_list);
+static DEFINE_MUTEX(drm_client_remove_defer_list_lock);
+
+static void drm_client_remove_defer_work_fn(struct work_struct *work)
+{
+	struct drm_client_remove_defer *defer, *tmp;
+
+	mutex_lock(&drm_client_remove_defer_list_lock);
+	list_for_each_entry_safe(defer, tmp, &drm_client_remove_defer_list, list) {
+		drm_client_remove_safe(defer->dev, defer->client);
+		drm_dev_put(defer->dev);
+		list_del(&defer->list);
+		kfree(defer);
+	}
+	mutex_unlock(&drm_client_remove_defer_list_lock);
+}
+
+static DECLARE_WORK(drm_client_remove_defer_work, drm_client_remove_defer_work_fn);
+
+/**
+ * drm_client_remove_defer - Deferred client removal
+ * @client: Client
+ *
+ * Defer client removal to a worker. This makes it possible for a client running
+ * in a worker to remove itself.
+ *
+ * Returns:
+ * Zero on success, or -ENOMEM on allocation failure.
+ */
+int drm_client_remove_defer(struct drm_client_dev *client)
+{
+	struct drm_client_remove_defer *defer;
+
+	if (!client)
+		return 0;
+
+	defer = kzalloc(sizeof(*defer), GFP_KERNEL);
+	if (!defer)
+		return -ENOMEM;
+
+	defer->dev = client->dev;
+	defer->client = client;
+	drm_dev_get(client->dev);
+
+	mutex_lock(&drm_client_remove_defer_list_lock);
+	list_add(&defer->list, &drm_client_remove_defer_list);
+	mutex_unlock(&drm_client_remove_defer_list_lock);
+
+	schedule_work(&drm_client_remove_defer_work);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_client_remove_defer);
+
+void drm_client_exit(void)
+{
+	flush_work(&drm_client_remove_defer_work);
+}
+
+void drm_client_dev_unregister(struct drm_device *dev)
+{
+	struct drm_client_dev *client, *tmp;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry_safe(client, tmp, &dev->clientlist, list)
+		drm_client_remove_locked(client);
+	mutex_unlock(&dev->clientlist_mutex);
+}
+
+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->hotplug)
+			continue;
+
+		ret = client->funcs->hotplug(client);
+		DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->funcs->name, ret);
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+EXPORT_SYMBOL(drm_client_dev_hotplug);
+
+void drm_client_dev_lastclose(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->lastclose)
+			continue;
+
+		ret = client->funcs->lastclose(client);
+		DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->funcs->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;
@@ -218,6 +431,9 @@ static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
 	/* drop the reference we picked up in framebuffer lookup */
 	drm_framebuffer_put(buffer->fb);
 
+	if (client->funcs)
+		strscpy(buffer->fb->comm, client->funcs->name, TASK_COMM_LEN);
+
 	return 0;
 }
 
@@ -265,3 +481,31 @@ void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
 	drm_client_buffer_delete(buffer);
 }
 EXPORT_SYMBOL(drm_client_framebuffer_delete);
+
+#ifdef CONFIG_DEBUG_FS
+static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_printer p = drm_seq_file_printer(m);
+	struct drm_client_dev *client;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list)
+		drm_printf(&p, "%s\n", client->funcs->name);
+	mutex_unlock(&dev->clientlist_mutex);
+
+	return 0;
+}
+
+static const struct drm_info_list drm_client_debugfs_list[] = {
+	{ "internal_clients", drm_client_debugfs_internal_clients, 0 },
+};
+
+int drm_client_debugfs_init(struct drm_minor *minor)
+{
+	return drm_debugfs_create_files(drm_client_debugfs_list,
+					ARRAY_SIZE(drm_client_debugfs_list),
+					minor->debugfs_root, minor);
+}
+#endif
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index b2482818fee8..50a20bfc07ea 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/export.h>
 
+#include <drm/drm_client.h>
 #include <drm/drm_debugfs.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_atomic.h>
@@ -164,6 +165,12 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 			DRM_ERROR("Failed to create framebuffer debugfs file\n");
 			return ret;
 		}
+
+		ret = drm_client_debugfs_init(minor);
+		if (ret) {
+			DRM_ERROR("Failed to create client debugfs file\n");
+			return ret;
+		}
 	}
 
 	if (dev->driver->debugfs_init) {
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 67ac793a7108..d7c1ceebd0de 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);
@@ -854,6 +859,8 @@ void drm_dev_unregister(struct drm_device *dev)
 {
 	struct drm_map_list *r_list, *list_temp;
 
+	drm_client_dev_unregister(dev);
+
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 		drm_lastclose(dev);
 
@@ -959,6 +966,7 @@ static const struct file_operations drm_stub_fops = {
 
 static void drm_core_exit(void)
 {
+	drm_client_exit();
 	unregister_chrdev(DRM_MAJOR, "drm");
 	debugfs_remove(drm_debugfs_root);
 	drm_sysfs_destroy();
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index 76e2f7977779..aff3c215d9e5 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -180,7 +180,7 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
 	if (!fbdev_cma)
 		return ERR_PTR(-ENOMEM);
 
-	client = drm_client_new(dev);
+	client = drm_client_new(dev, NULL);
 	if (IS_ERR(client)) {
 		ret = PTR_ERR(client);
 		goto err_free;
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 55505378df47..bcc688e58776 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_lastclose(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 11379eaf3118..011a87ad3406 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -5,11 +5,56 @@
 
 #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 {
+	/**
+	 * @name:
+	 *
+	 * Name of the client. Mandatory.
+	 */
+	const char *name;
+
+	/**
+	 * @remove:
+	 *
+	 * Called when a &drm_device is unregistered or the client is
+	 * unregistered. If zero is returned drm_client_free() is called
+	 * automatically. If the client can't drop it's resources it should
+	 * return non-zero and call drm_client_free() later.
+	 *
+	 * This callback is optional.
+	 */
+	int (*remove)(struct drm_client_dev *client);
+
+	/**
+	 * @lastclose:
+	 *
+	 * 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 optional.
+	 */
+	int (*lastclose)(struct drm_client_dev *client);
+
+	/**
+	 * @hotplug:
+	 *
+	 * Called on drm_kms_helper_hotplug_event().
+	 *
+	 * This callback is optional.
+	 */
+	int (*hotplug)(struct drm_client_dev *client);
+};
+
 /**
  * struct drm_client_dev - DRM client instance
  */
@@ -27,6 +72,11 @@ struct drm_client_dev {
 	 */
 	struct drm_device *dev;
 
+	/**
+	 * @funcs: DRM client functions
+	 */
+	const struct drm_client_funcs *funcs;
+
 	/**
 	 * @file: DRM file
 	 */
@@ -39,7 +89,20 @@ struct drm_client_dev {
 };
 
 void drm_client_free(struct drm_client_dev *client);
-struct drm_client_dev *drm_client_new(struct drm_device *dev);
+struct drm_client_dev *
+drm_client_new(struct drm_device *dev, const struct drm_client_funcs *funcs);
+struct drm_client_dev *
+drm_client_new_from_id(unsigned int minor_id, const struct drm_client_funcs *funcs);
+void drm_client_remove(struct drm_client_dev *client);
+int drm_client_remove_defer(struct drm_client_dev *client);
+
+void drm_client_exit(void);
+
+void drm_client_dev_unregister(struct drm_device *dev);
+void drm_client_dev_hotplug(struct drm_device *dev);
+void drm_client_dev_lastclose(struct drm_device *dev);
+
+int drm_client_debugfs_init(struct drm_minor *minor);
 
 /**
  * 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

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
