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// SPDX-License-Identifier: GPL-2.0/* * (C) COPYRIGHT 2016 ARM Limited. All rights reserved. * Author: Brian Starkey <brian.starkey@arm.com> * * This program is free software and is provided to you under the terms of the * GNU General Public License version 2 as published by the Free Software * Foundation, and any use by you of this program is subject to the terms * of such GNU licence. */ #include <linux/dma-fence.h>#include <linux/export.h> #include <drm/drm_crtc.h>#include <drm/drm_device.h>#include <drm/drm_drv.h>#include <drm/drm_framebuffer.h>#include <drm/drm_managed.h>#include <drm/drm_modeset_helper_vtables.h>#include <drm/drm_property.h>#include <drm/drm_writeback.h> /** * DOC: overview * * Writeback connectors are used to expose hardware which can write the output * from a CRTC to a memory buffer. They are used and act similarly to other * types of connectors, with some important differences: * * * Writeback connectors don't provide a way to output visually to the user. * * * Writeback connectors are visible to userspace only when the client sets *   DRM_CLIENT_CAP_WRITEBACK_CONNECTORS. * * * Writeback connectors don't have EDID. * * A framebuffer may only be attached to a writeback connector when the * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the * framebuffer applies only to a single commit (see below). A framebuffer may * not be attached while the CRTC is off. * * Unlike with planes, when a writeback framebuffer is removed by userspace DRM * makes no attempt to remove it from active use by the connector. This is * because no method is provided to abort a writeback operation, and in any * case making a new commit whilst a writeback is ongoing is undefined (see * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished, * the framebuffer will automatically no longer be in active use. As it will * also have already been removed from the framebuffer list, there will be no * way for any userspace application to retrieve a reference to it in the * intervening period. * * Writeback connectors have some additional properties, which userspace * can use to query and control them: * *  "WRITEBACK_FB_ID": *	Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the *	framebuffer to be written by the writeback connector. This property is *	similar to the FB_ID property on planes, but will always read as zero *	and is not preserved across commits. *	Userspace must set this property to an output buffer every time it *	wishes the buffer to get filled. * *  "WRITEBACK_PIXEL_FORMATS": *	Immutable blob property to store the supported pixel formats table. The *	data is an array of u32 DRM_FORMAT_* fourcc values. *	Userspace can use this blob to find out what pixel formats are supported *	by the connector's writeback engine. * *  "WRITEBACK_OUT_FENCE_PTR": *	Userspace can use this property to provide a pointer for the kernel to *	fill with a sync_file file descriptor, which will signal once the *	writeback is finished. The value should be the address of a 32-bit *	signed integer, cast to a u64. *	Userspace should wait for this fence to signal before making another *	commit affecting any of the same CRTCs, Planes or Connectors. *	**Failure to do so will result in undefined behaviour.** *	For this reason it is strongly recommended that all userspace *	applications making use of writeback connectors *always* retrieve an *	out-fence for the commit and use it appropriately. *	From userspace, this property will always read as zero. */ #define fence_to_wb_connector(x) container_of(x->lock, \					      struct drm_writeback_connector, \					      fence_lock) static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence){	struct drm_writeback_connector *wb_connector =		fence_to_wb_connector(fence); 	return wb_connector->base.dev->driver->name;} static const char *drm_writeback_fence_get_timeline_name(struct dma_fence *fence){	struct drm_writeback_connector *wb_connector =		fence_to_wb_connector(fence); 	return wb_connector->timeline_name;} static const struct dma_fence_ops drm_writeback_fence_ops = {	.get_driver_name = drm_writeback_fence_get_driver_name,	.get_timeline_name = drm_writeback_fence_get_timeline_name,}; static int create_writeback_properties(struct drm_device *dev){	struct drm_property *prop; 	if (!dev->mode_config.writeback_fb_id_property) {		prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,						  "WRITEBACK_FB_ID",						  DRM_MODE_OBJECT_FB);		if (!prop)			return -ENOMEM;		dev->mode_config.writeback_fb_id_property = prop;	} 	if (!dev->mode_config.writeback_pixel_formats_property) {		prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |					   DRM_MODE_PROP_ATOMIC |					   DRM_MODE_PROP_IMMUTABLE,					   "WRITEBACK_PIXEL_FORMATS", 0);		if (!prop)			return -ENOMEM;		dev->mode_config.writeback_pixel_formats_property = prop;	} 	if (!dev->mode_config.writeback_out_fence_ptr_property) {		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,						 "WRITEBACK_OUT_FENCE_PTR", 0,						 U64_MAX);		if (!prop)			return -ENOMEM;		dev->mode_config.writeback_out_fence_ptr_property = prop;	} 	return 0;} static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {	.destroy = drm_encoder_cleanup,}; /** * drm_writeback_connector_init - Initialize a writeback connector and its properties * @dev: DRM device * @wb_connector: Writeback connector to initialize * @con_funcs: Connector funcs vtable * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder * @formats: Array of supported pixel formats for the writeback engine * @n_formats: Length of the formats array * @possible_crtcs: possible crtcs for the internal writeback encoder * * This function creates the writeback-connector-specific properties if they * have not been already created, initializes the connector as * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property * values. It will also create an internal encoder associated with the * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for * the encoder helper. * * Drivers should always use this function instead of drm_connector_init() to * set up writeback connectors. * * Returns: 0 on success, or a negative error code */int drm_writeback_connector_init(struct drm_device *dev,				 struct drm_writeback_connector *wb_connector,				 const struct drm_connector_funcs *con_funcs,				 const struct drm_encoder_helper_funcs *enc_helper_funcs,				 const u32 *formats, int n_formats,				 u32 possible_crtcs){	int ret = 0; 	drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs); 	wb_connector->encoder.possible_crtcs = possible_crtcs; 	ret = drm_encoder_init(dev, &wb_connector->encoder,			       &drm_writeback_encoder_funcs,			       DRM_MODE_ENCODER_VIRTUAL, NULL);	if (ret)		return ret; 	ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,			con_funcs, formats, n_formats); 	if (ret)		drm_encoder_cleanup(&wb_connector->encoder); 	return ret;}EXPORT_SYMBOL(drm_writeback_connector_init); static void delete_writeback_properties(struct drm_device *dev){	if (dev->mode_config.writeback_pixel_formats_property) {		drm_property_destroy(dev, dev->mode_config.writeback_pixel_formats_property);		dev->mode_config.writeback_pixel_formats_property = NULL;	}	if (dev->mode_config.writeback_out_fence_ptr_property) {		drm_property_destroy(dev, dev->mode_config.writeback_out_fence_ptr_property);		dev->mode_config.writeback_out_fence_ptr_property = NULL;	}	if (dev->mode_config.writeback_fb_id_property) {		drm_property_destroy(dev, dev->mode_config.writeback_fb_id_property);		dev->mode_config.writeback_fb_id_property = NULL;	}} /** * __drm_writeback_connector_init - Initialize a writeback connector with * a custom encoder * * @dev: DRM device * @wb_connector: Writeback connector to initialize * @enc: handle to the already initialized drm encoder * @formats: Array of supported pixel formats for the writeback engine * @n_formats: Length of the formats array * * This function creates the writeback-connector-specific properties if they * have not been already created, initializes the connector as * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property * values. * * This function assumes that the drm_writeback_connector's encoder has already been * created and initialized before invoking this function. * * In addition, this function also assumes that callers of this API will manage * assigning the encoder helper functions, possible_crtcs and any other encoder * specific operation. * * Returns: 0 on success, or a negative error code */static int __drm_writeback_connector_init(struct drm_device *dev,					  struct drm_writeback_connector *wb_connector,					  struct drm_encoder *enc, const u32 *formats,					  int n_formats){	struct drm_connector *connector = &wb_connector->base;	struct drm_mode_config *config = &dev->mode_config;	struct drm_property_blob *blob;	int ret = create_writeback_properties(dev); 	if (ret != 0)		goto failed_properties; 	connector->interlace_allowed = 0; 	ret = drm_connector_attach_encoder(connector, enc);	if (ret)		goto failed_properties; 	blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),					formats);	if (IS_ERR(blob)) {		ret = PTR_ERR(blob);		goto failed_properties;	} 	INIT_LIST_HEAD(&wb_connector->job_queue);	spin_lock_init(&wb_connector->job_lock); 	wb_connector->fence_context = dma_fence_context_alloc(1);	spin_lock_init(&wb_connector->fence_lock);	snprintf(wb_connector->timeline_name,		 sizeof(wb_connector->timeline_name),		 "CONNECTOR:%d-%s", connector->base.id, connector->name); 	drm_object_attach_property(&connector->base,				   config->writeback_out_fence_ptr_property, 0); 	drm_object_attach_property(&connector->base,				   config->writeback_fb_id_property, 0); 	drm_object_attach_property(&connector->base,				   config->writeback_pixel_formats_property,				   blob->base.id);	wb_connector->pixel_formats_blob_ptr = blob; 	return 0;failed_properties:	delete_writeback_properties(dev);	return ret;} /** * drm_writeback_connector_init_with_encoder - Initialize a writeback connector with * a custom encoder * * @dev: DRM device * @wb_connector: Writeback connector to initialize * @enc: handle to the already initialized drm encoder * @con_funcs: Connector funcs vtable * @formats: Array of supported pixel formats for the writeback engine * @n_formats: Length of the formats array * * This function creates the writeback-connector-specific properties if they * have not been already created, initializes the connector as * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property * values. * * This function assumes that the drm_writeback_connector's encoder has already been * created and initialized before invoking this function. * * In addition, this function also assumes that callers of this API will manage * assigning the encoder helper functions, possible_crtcs and any other encoder * specific operation. * * Drivers should always use this function instead of drm_connector_init() to * set up writeback connectors if they want to manage themselves the lifetime of the * associated encoder. * * Returns: 0 on success, or a negative error code */int drm_writeback_connector_init_with_encoder(struct drm_device *dev,					      struct drm_writeback_connector *wb_connector,					      struct drm_encoder *enc,					      const struct drm_connector_funcs *con_funcs,					      const u32 *formats, int n_formats){	struct drm_connector *connector = &wb_connector->base;	int ret; 	ret = drm_connector_init(dev, connector, con_funcs,				 DRM_MODE_CONNECTOR_WRITEBACK);	if (ret)		return ret; 	ret = __drm_writeback_connector_init(dev, wb_connector, enc, formats,					     n_formats);	if (ret)		drm_connector_cleanup(connector); 	return ret;}EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder); /** * drm_writeback_connector_cleanup - Cleanup the writeback connector * @dev: DRM device * @data: Pointer to the writeback connector to clean up * * This will decrement the reference counter of blobs and destroy properties. It * will also clean the remaining jobs in this writeback connector. Caution: This helper will not * clean up the attached encoder and the drm_connector. */static void drm_writeback_connector_cleanup(struct drm_device *dev,					    void *data){	unsigned long flags;	struct drm_writeback_job *pos, *n;	struct drm_writeback_connector *wb_connector = data; 	delete_writeback_properties(dev);	drm_property_blob_put(wb_connector->pixel_formats_blob_ptr); 	spin_lock_irqsave(&wb_connector->job_lock, flags);	list_for_each_entry_safe(pos, n, &wb_connector->job_queue, list_entry) {		list_del(&pos->list_entry);		drm_writeback_cleanup_job(pos);	}	spin_unlock_irqrestore(&wb_connector->job_lock, flags);} /** * drmm_writeback_connector_init - Initialize a writeback connector with * a custom encoder * * @dev: DRM device * @wb_connector: Writeback connector to initialize * @con_funcs: Connector funcs vtable * @enc: Encoder to connect this writeback connector * @formats: Array of supported pixel formats for the writeback engine * @n_formats: Length of the formats array * * This function initialize a writeback connector and register its cleanup. * * This function creates the writeback-connector-specific properties if they * have not been already created, initializes the connector as * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property * values. * * Returns: 0 on success, or a negative error code */int drmm_writeback_connector_init(struct drm_device *dev,				  struct drm_writeback_connector *wb_connector,				  const struct drm_connector_funcs *con_funcs,				  struct drm_encoder *enc,				  const u32 *formats, int n_formats){	struct drm_connector *connector = &wb_connector->base;	int ret; 	ret = drmm_connector_init(dev, connector, con_funcs,				  DRM_MODE_CONNECTOR_WRITEBACK, NULL);	if (ret)		return ret; 	ret = __drm_writeback_connector_init(dev, wb_connector, enc, formats,					     n_formats);	if (ret)		return ret; 	ret = drmm_add_action_or_reset(dev, drm_writeback_connector_cleanup,				       wb_connector);	if (ret)		return ret; 	return 0;}EXPORT_SYMBOL(drmm_writeback_connector_init); int drm_writeback_set_fb(struct drm_connector_state *conn_state,			 struct drm_framebuffer *fb){	WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK); 	if (!conn_state->writeback_job) {		conn_state->writeback_job = kzalloc_obj(*conn_state->writeback_job);		if (!conn_state->writeback_job)			return -ENOMEM; 		conn_state->writeback_job->connector =			drm_connector_to_writeback(conn_state->connector);	} 	drm_framebuffer_assign(&conn_state->writeback_job->fb, fb);	return 0;} int drm_writeback_prepare_job(struct drm_writeback_job *job){	struct drm_writeback_connector *connector = job->connector;	const struct drm_connector_helper_funcs *funcs =		connector->base.helper_private;	int ret; 	if (funcs->prepare_writeback_job) {		ret = funcs->prepare_writeback_job(connector, job);		if (ret < 0)			return ret;	} 	job->prepared = true;	return 0;}EXPORT_SYMBOL(drm_writeback_prepare_job); /** * drm_writeback_queue_job - Queue a writeback job for later signalling * @wb_connector: The writeback connector to queue a job on * @conn_state: The connector state containing the job to queue * * This function adds the job contained in @conn_state to the job_queue for a * writeback connector. It takes ownership of the writeback job and sets the * @conn_state->writeback_job to NULL, and so no access to the job may be * performed by the caller after this function returns. * * Drivers must ensure that for a given writeback connector, jobs are queued in * exactly the same order as they will be completed by the hardware (and * signaled via drm_writeback_signal_completion). * * For every call to drm_writeback_queue_job() there must be exactly one call to * drm_writeback_signal_completion() * * See also: drm_writeback_signal_completion() */void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,			     struct drm_connector_state *conn_state){	struct drm_writeback_job *job;	unsigned long flags; 	job = conn_state->writeback_job;	conn_state->writeback_job = NULL; 	spin_lock_irqsave(&wb_connector->job_lock, flags);	list_add_tail(&job->list_entry, &wb_connector->job_queue);	spin_unlock_irqrestore(&wb_connector->job_lock, flags);}EXPORT_SYMBOL(drm_writeback_queue_job); void drm_writeback_cleanup_job(struct drm_writeback_job *job){	struct drm_writeback_connector *connector = job->connector;	const struct drm_connector_helper_funcs *funcs =		connector->base.helper_private; 	if (job->prepared && funcs->cleanup_writeback_job)		funcs->cleanup_writeback_job(connector, job); 	if (job->fb)		drm_framebuffer_put(job->fb); 

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