From patchwork Fri Sep 13 21:46:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 13804110 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2144A6BFD4 for ; Fri, 13 Sep 2024 21:47:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726264038; cv=none; b=hoWfAuDtN4piTjxXpAIubz4vszS/fWEaZZlfXt+xxtfhC5/nko1yVrx95rzP3PJfydeNEZX/sDCtv/Spb5Z01H3AMUPKmYbeweSr7FDnReIp7R05C02OshQM4hNVFl4xqXCTng0HHBeazszSuVJPpjqvEQPR3OlfQh2CQ6SSf/g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726264038; c=relaxed/simple; bh=LXaWD9KIdKV1BX3OScWS0sAEKTLeBqsNcj+9a5HDpLQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pJlVzloA9G9mb2vx5PksrQDYtKGQo7ECJGWsWH4pVRqkgVfr4m00tYPZesVEIz7YTCU5cfDZqa2U8qsTzkEC8vh7xtS7w9wDJnauO9C7pwzFujCn4hSnb8+ROWcU0lQ0NrLVddQhAPZK7BRJhBIiROv814rvmolZDUrlZ+K+xic= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=Pg7hnVNN; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="Pg7hnVNN" Received: from ideasonboard.com (213-229-8-243.static.upcbusiness.at [213.229.8.243]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B4AE91083; Fri, 13 Sep 2024 23:45:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1726263948; bh=LXaWD9KIdKV1BX3OScWS0sAEKTLeBqsNcj+9a5HDpLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pg7hnVNN6moh8dJ/g3OHytTz1tJjorOe+/o0fU3TrCilAdFRJi+2LvsnUmzmmuQZE Vi3caaSV2FMtgGyoFdR30X3ccNAfNBrlhtJQTugPdCKXIfg6LfQTJgBjJwN0AFDECJ clT5HUDTx9NnTIYWNiefOfoMn9auf5a7GNL8EsKw= From: Jacopo Mondi To: linux-media@vger.kernel.org Cc: Jacopo Mondi , Laurent Pinchart Subject: [PATCH 01/10] media: media-entity: Introduce media_entity_context Date: Fri, 13 Sep 2024 23:46:46 +0200 Message-ID: <20240913214657.1502838-2-jacopo.mondi@ideasonboard.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240913214657.1502838-1-jacopo.mondi@ideasonboard.com> References: <20240913214657.1502838-1-jacopo.mondi@ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Introduce the 'struct media_entity_context' type, which serves for reference counting and introduce two new media entity operations to allow drivers to allocate and free a media entity context. The newly introduced type will be used as a base type for the device context types (video_device_context and v4l2_subdevice_context) that will be introduced in the next patches. Signed-off-by: Jacopo Mondi --- drivers/media/mc/mc-entity.c | 46 +++++++++++++++++ include/media/media-entity.h | 99 ++++++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+) diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c index 951b79ca125c..8ce72d72bc1d 100644 --- a/drivers/media/mc/mc-entity.c +++ b/drivers/media/mc/mc-entity.c @@ -1660,3 +1660,49 @@ struct media_link *__media_entity_next_link(struct media_entity *entity, return NULL; } EXPORT_SYMBOL_GPL(__media_entity_next_link); + +static void media_entity_release_context(struct kref *refcount) +{ + struct media_entity_context *ctx = + container_of(refcount, struct media_entity_context, refcount); + + ctx->entity->ops->destroy_context(ctx); +} + +struct media_entity_context * +media_entity_context_get(struct media_entity_context *ctx) +{ + if (!ctx) + return ERR_PTR(-EINVAL); + + kref_get(&ctx->refcount); + + return ctx; +} +EXPORT_SYMBOL_GPL(media_entity_context_get); + +void media_entity_context_put(struct media_entity_context *ctx) +{ + if (!ctx) + return; + + kref_put(&ctx->refcount, media_entity_release_context); +} +EXPORT_SYMBOL_GPL(media_entity_context_put); + +void media_entity_init_context(struct media_entity *entity, + struct media_entity_context *ctx) +{ + if (!ctx) + return; + + ctx->entity = entity; + kref_init(&ctx->refcount); + INIT_LIST_HEAD(&ctx->list); +} +EXPORT_SYMBOL_GPL(media_entity_init_context); + +void media_entity_cleanup_context(struct media_entity_context *ctx) +{ +} +EXPORT_SYMBOL_GPL(media_entity_cleanup_context); diff --git a/include/media/media-entity.h b/include/media/media-entity.h index 4d95893c8984..002a326de9b9 100644 --- a/include/media/media-entity.h +++ b/include/media/media-entity.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -248,6 +249,37 @@ struct media_pad { struct media_pipeline *pipe; }; +/** + * struct media_entity_context - A media entity execution context + * @mdev_context: The media device context this media entity is bound to. + * The field is initialized when the entity is bound to a media + * device context. + * @entity: The media entity this context belongs to + * @refcount: The kref reference counter + * list: The list entry to link the entity context in the media device context + * + * This type represent the 'base class' used to implement execution context for + * video device contexts and subdevice contexts. Those types embedds an instance + * of 'struct media_entity_context' as their first member, allowing the MC core + * to implement type polymorphism and handle video device and subdevice contexts + * transparently. + * + * The main function of this type is to provide reference counting for the + * 'dervived' device context types. The video device and subdevice core + * populates the 'context_release' function pointer that implement specific + * clean-up operations, similar to what a 'virtual destructor' would do in C++. + * + * Drivers are not expected to use this type directly, but only the MC core + * will. + */ +struct media_device_context; +struct media_entity_context { + struct media_device_context *mdev_context; + struct media_entity *entity; + struct kref refcount; + struct list_head list; +}; + /** * struct media_entity_operations - Media entity operations * @get_fwnode_pad: Return the pad number based on a fwnode endpoint or @@ -269,6 +301,15 @@ struct media_pad { * media_entity_has_pad_interdep(). * Optional: If the operation isn't implemented all pads * will be considered as interdependent. + * @alloc_context: Allocate a media entity context. Drivers are allowed to + * sub-class the entity context type by defining a driver + * specific type that embeds an instance of either a + * video_device_context or subdevice_context as first + * member, and allocate the size of a driver-specific type + * in the implementation of this operation. Returns 0 for + * success, or an error code < 0 otherwise. + * @destroy_context: Release a media entity context previously allocated by + * the driver. * * .. note:: * @@ -284,6 +325,9 @@ struct media_entity_operations { int (*link_validate)(struct media_link *link); bool (*has_pad_interdep)(struct media_entity *entity, unsigned int pad0, unsigned int pad1); + int (*alloc_context)(struct media_entity *entity, + struct media_entity_context **context); + void (*destroy_context)(struct media_entity_context *context); }; /** @@ -1452,3 +1496,58 @@ struct media_link *__media_entity_next_link(struct media_entity *entity, MEDIA_LNK_FL_DATA_LINK)) #endif + +/** + * media_entity_context_get - Increase the media entity context reference count + * and return a reference to it + * + * @ctx: the media entity context + * + * Increase the media entity context reference count. The reference count + * is increased by the V4L2 core when: + * + * - a new context is allocated when bounding a media entity to a media device + * context (by kref_init()) + * - the media pipeline the context is part of starts streaming + * + * The entity context gets automatically decreased by the V4L2 core when: + * - a context is unbound + * - the pipeline stops streaming + */ +struct media_entity_context * +media_entity_context_get(struct media_entity_context *ctx); + +/** + * media_entity_context_put - Decrease the media entity context reference count + * + * @ctx: the media entity context + * + * Decrease the media entity context reference count. The reference count + * is decreased by the V4L2 core when: + * - the file handle the context is associated with is closed + * - the media pipeline the context is part of is stopped + */ +void media_entity_context_put(struct media_entity_context *ctx); + +/** + * media_entity_init_context - Initialize the media entity context + * + * @entity: the media entity this context belongs to + * @ctx: the media entity context + * + * Initialize the media entity context by initializing the kref reference + * counter. The intended caller of this function are the video device context + * and subdevic context initialize functions. + */ +void media_entity_init_context(struct media_entity *entity, + struct media_entity_context *ctx); + +/** + * media_entity_cleanup_context - Cleanup the media entity context + * + * @ctx: the media entity context + * + * Cleanup the media entity context. The intended caller of this function are + * the video device and subdevice context cleanup functions. + */ +void media_entity_cleanup_context(struct media_entity_context *ctx);