From patchwork Mon Jan 29 06:30:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunfei Dong X-Patchwork-Id: 13534982 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A27CC47DDF for ; Mon, 29 Jan 2024 06:31:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3EE821124B3; Mon, 29 Jan 2024 06:30:56 +0000 (UTC) Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by gabe.freedesktop.org (Postfix) with ESMTPS id 020981124B2 for ; Mon, 29 Jan 2024 06:30:51 +0000 (UTC) X-UUID: eed795d0be6f11eea2298b7352fd921d-20240129 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=VBRSF4YwZCz5T0Zk1nE7YVf8B1quLvMs45dUf37h/JQ=; b=OMBdsH8LvgJFk4uHD47/XD/hQyXmcP1yXYobnaQuM+gxqhjUKSE+f3yFO6tv7G273MKUX08ko7njJ+f7CxPwPLbCRgGpMAugaN3D5XfP82ckC7WSKxt89VyZLMRGgv4MbnCkjxjpC+eauFXMXWiiQLI9dqWevPRl+EecxYApd8M=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.36, REQID:6d561463-008a-4c56-bc1b-29aa5dd3f193, IP:0, U RL:0,TC:0,Content:-25,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-25 X-CID-META: VersionHash:6e16cf4, CLOUDID:d9b5c38e-e2c0-40b0-a8fe-7c7e47299109, B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:0,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1, SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0 X-CID-BVR: 0 X-CID-BAS: 0,_,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-UUID: eed795d0be6f11eea2298b7352fd921d-20240129 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 812860472; Mon, 29 Jan 2024 14:30:45 +0800 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs11n2.mediatek.inc (172.21.101.187) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Mon, 29 Jan 2024 14:30:44 +0800 Received: from mhfsdcap04.gcn.mediatek.inc (10.17.3.154) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Mon, 29 Jan 2024 14:30:42 +0800 From: Yunfei Dong To: Jeffrey Kardatzke , =?utf-8?q?N=C3=ADcolas_F_=2E_?= =?utf-8?q?R_=2E_A_=2E_Prado?= , Nicolas Dufresne , Hans Verkuil , AngeloGioacchino Del Regno , Benjamin Gaignard , Nathan Hebert Subject: [PATCH v4,06/22] dma-heap: Add proper kref handling on dma-buf heaps Date: Mon, 29 Jan 2024 14:30:09 +0800 Message-ID: <20240129063025.29251-7-yunfei.dong@mediatek.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240129063025.29251-1-yunfei.dong@mediatek.com> References: <20240129063025.29251-1-yunfei.dong@mediatek.com> MIME-Version: 1.0 X-MTK: N X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Project_Global_Chrome_Upstream_Group@mediatek.com, Steve Cho , =?utf-8?q?Christian_K=C3=B6nig?= , Yunfei Dong , Chen-Yu Tsai , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, Matthias Brugger , John Stultz , linux-arm-kernel@lists.infradead.org, Daniel Vetter , Hsin-Yi Wang , Fritz Koenig , linux-mediatek@lists.infradead.org, "T . J . Mercier" , Sumit Semwal , Yong Wu Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: John Stultz Add proper refcounting on the dma_heap structure. While existing heaps are built-in, we may eventually have heaps loaded from modules, and we'll need to be able to properly handle the references to the heaps Signed-off-by: John Stultz Signed-off-by: T.J. Mercier Signed-off-by: Yong Wu [Yong: Just add comment for "minor" and "refcount"] Signed-off-by: Yunfei Dong --- drivers/dma-buf/dma-heap.c | 29 +++++++++++++++++++++++++++++ include/linux/dma-heap.h | 2 ++ 2 files changed, 31 insertions(+) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 22f6c193db0d..97025ee8500f 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -30,6 +31,7 @@ * @heap_devt: heap device node * @list: list head connecting to list of heaps * @heap_cdev: heap char device + * @refcount: reference counter for this heap device * * Represents a heap of memory from which buffers can be made. */ @@ -40,6 +42,7 @@ struct dma_heap { dev_t heap_devt; struct list_head list; struct cdev heap_cdev; + struct kref refcount; }; static LIST_HEAD(heap_list); @@ -240,6 +243,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) if (!heap) return ERR_PTR(-ENOMEM); + kref_init(&heap->refcount); heap->name = exp_info->name; heap->ops = exp_info->ops; heap->priv = exp_info->priv; @@ -304,6 +308,31 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) return err_ret; } +static void dma_heap_release(struct kref *ref) +{ + struct dma_heap *heap = container_of(ref, struct dma_heap, refcount); + unsigned int minor = MINOR(heap->heap_devt); + + mutex_lock(&heap_list_lock); + list_del(&heap->list); + mutex_unlock(&heap_list_lock); + + device_destroy(dma_heap_class, heap->heap_devt); + cdev_del(&heap->heap_cdev); + xa_erase(&dma_heap_minors, minor); + + kfree(heap); +} + +/** + * dma_heap_put - drops a reference to a dmabuf heap, potentially freeing it + * @heap: DMA-Heap whose reference count to decrement + */ +void dma_heap_put(struct dma_heap *heap) +{ + kref_put(&heap->refcount, dma_heap_release); +} + static char *dma_heap_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev)); diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index fbe86ec889a8..d57593f8a1bc 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -46,4 +46,6 @@ const char *dma_heap_get_name(struct dma_heap *heap); struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); +void dma_heap_put(struct dma_heap *heap); + #endif /* _DMA_HEAPS_H */