[Intel-gfx] [PATCH v4 5/9] drm/client: Add client callbacks

Daniel Vetter daniel at ffwll.ch
Tue Jul 3 07:46:05 UTC 2018


On Mon, Jul 02, 2018 at 03:54:29PM +0200, Noralf Trønnes wrote:
> Add client callbacks and hook them up.
> Add a list of clients per drm_device.
> 
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>

btw for reviewing it'd be simpler if you merge the 2 patches that add the
client library, avoids me having to jump back&forth ..

Bunch of comments below still.
-Daniel

> ---
>  drivers/gpu/drm/drm_client.c        | 92 ++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/drm_drv.c           |  7 +++
>  drivers/gpu/drm/drm_fb_cma_helper.c |  2 +-
>  drivers/gpu/drm/drm_fb_helper.c     | 11 ++++-
>  drivers/gpu/drm/drm_file.c          |  3 ++
>  drivers/gpu/drm/drm_probe_helper.c  |  3 ++
>  include/drm/drm_client.h            | 75 +++++++++++++++++++++++++++++-
>  include/drm/drm_device.h            | 14 ++++++
>  8 files changed, 201 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 9c9b8ac7aea3..f05ee98bd10c 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -4,6 +4,7 @@
>   */
>  
>  #include <linux/list.h>
> +#include <linux/module.h>
>  #include <linux/mutex.h>
>  #include <linux/seq_file.h>
>  #include <linux/slab.h>
> @@ -66,6 +67,7 @@ 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.
>   *
> @@ -73,24 +75,47 @@ 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) ||
>  	    !dev->driver->dumb_create || !dev->driver->gem_prime_vmap)
>  		return -ENOTSUPP;
>  
> +	if (funcs && !try_module_get(funcs->owner))
> +		return -ENODEV;
> +
>  	client->dev = dev;
>  	client->name = name;
> +	client->funcs = funcs;
>  
>  	ret = drm_client_open(client);
>  	if (ret)
> -		return ret;
> +		goto err_put_module;
> +
> +	mutex_lock(&dev->clientlist_mutex);
> +	registered = dev->registered;
> +	if (registered)
> +		list_add(&client->list, &dev->clientlist);
> +	mutex_unlock(&dev->clientlist_mutex);
> +	if (!registered) {
> +		ret = -ENODEV;
> +		goto err_close;
> +	}
>  
>  	drm_dev_get(dev);

This only works if the caller holds a reference for us on dev already, or
has some other guarantee that it won't disappear. Would be good to mention
this in the kerneldoc.

>  	return 0;
> +
> +err_close:
> +	drm_client_close(client);
> +err_put_module:
> +	if (funcs)
> +		module_put(funcs->owner);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(drm_client_new);
>  
> @@ -116,9 +141,72 @@ void drm_client_release(struct drm_client_dev *client)
>  
>  	drm_client_close(client);
>  	drm_dev_put(dev);
> +	if (client->funcs)
> +		module_put(client->funcs->owner);
>  }
>  EXPORT_SYMBOL(drm_client_release);
>  
> +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) {
> +		list_del(&client->list);
> +		if (client->funcs && client->funcs->unregister) {
> +			client->funcs->unregister(client);

Hm, not ->unregister is called while holding the lock. I thought that
blows up for you?

> +		} else {
> +			drm_client_release(client);
> +			kfree(client);
> +		}
> +	}
> +	mutex_unlock(&dev->clientlist_mutex);
> +}
> +

Needs a bit of kerneldoc here since exported function. Drivers might also
want to call this from their own hotplug handling.

> +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 = buffer->client->dev;
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index e7ff0b03328b..6eb935bb2f92 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 5762a7c441e9..718c7f961d8a 100644
> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> @@ -181,7 +181,7 @@ 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_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 0a0a577ebc3c..bea3a0cb324a 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -2989,8 +2989,15 @@ static void drm_fbdev_fb_destroy(struct fb_info *info)
>  	}
>  
>  	drm_client_framebuffer_delete(fb_helper->buffer);
> -	drm_client_release(&fb_helper->client);
> -	kfree(fb_helper);
> +	/*
> +	 * FIXME:
> +	 * Remove conditional when all CMA drivers have been moved over to using
> +	 * drm_fbdev_generic_setup().
> +	 */
> +	if (fb_helper->client.funcs) {
> +		drm_client_release(&fb_helper->client);
> +		kfree(fb_helper);
> +	}
>  }
>  
>  static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 66bb403dc8ab..ffa8dc35515f 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>
>  
> @@ -444,6 +445,8 @@ 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 e366f95d4414..02cbb02714d8 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -5,10 +5,66 @@
>  
>  #include <linux/types.h>
>  
> +struct drm_client_dev;
>  struct drm_device;
>  struct drm_file;
>  struct drm_framebuffer;
>  struct drm_gem_object;
> +struct module;
> +
> +/**
> + * struct drm_client_funcs - DRM client callbacks
> + */
> +struct drm_client_funcs {
> +	/**
> +	 * @owner: The module owner
> +	 */
> +	struct module *owner;
> +
> +	/**
> +	 * @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);

Hm, is this no longer in use?

> +
> +	/**
> +	 * @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 still talks about refcounting and _put ... needs a refresher.

> +	 *
> +	 * 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
> @@ -24,6 +80,19 @@ struct drm_client_dev {
>  	 */
>  	const char *name;
>  
> +	/**
> +	 * @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
>  	 */
> @@ -31,9 +100,13 @@ struct drm_client_dev {
>  };
>  
>  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_release(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
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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