From patchwork Tue Jan 23 22:12:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Davis X-Patchwork-Id: 13528205 Received: from fllv0016.ext.ti.com (fllv0016.ext.ti.com [198.47.19.142]) (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 E7F504E1BC; Tue, 23 Jan 2024 22:12:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.142 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706047962; cv=none; b=ZKDcCWYVrOGAXgvSoZugwXEExYHBNxbjfyREb9+EkFz2NQvtLeSXWSJjoU2DddNAFwZtAugnSGjuH9+6rpjfq6NCh0z+PQmRphNNM5hc1cA94lo6sCOUE2Zs2EFZ83PexrCSEujeKSgfuo4Y+9d3HkpHDAM1vkmpF/25lJzQK3Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706047962; c=relaxed/simple; bh=CRztiKPykN94Kw8MFMJkODoezf7JBtxEGR+Orm6jsLE=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Jkp/ykflxERCGu/kOFSEH+hSqGBPd4FzMEgF1L8qRjnACibrxEZt9T1B8O7UWoY1fkU38dONBKmUwuvJwydAWvEJQ4b590UP1ejiionniIU1+m0RT7tQwlQjHzKD5KoKsjsVCn6kkme/ssZT4WVPczsH8YgN+rqWQrdLlVgkIUY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=DecGlWmp; arc=none smtp.client-ip=198.47.19.142 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="DecGlWmp" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 40NMCT42037444; Tue, 23 Jan 2024 16:12:29 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1706047949; bh=OGIV3j+clxBo67VfFxeJr+1fZqQUuFmwD1CtXVTA4XY=; h=From:To:CC:Subject:Date; b=DecGlWmpJiUgKKkrhKox/YoNEPSIDxQP6JmO4S8TazFiU3jtRJfNsvCtXKPNSqGS+ QaTH+DLreiXAhT0ICFhloW18529tnbyA8/PcBHPDZtO1uAtv0/mnMOSkv+2VFs+jRa sAZ0+DWfkN4sZoYQ8BUlFhqVQIBTindWxni8BEtc= Received: from DLEE110.ent.ti.com (dlee110.ent.ti.com [157.170.170.21]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 40NMCTPA077837 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 23 Jan 2024 16:12:29 -0600 Received: from DLEE111.ent.ti.com (157.170.170.22) by DLEE110.ent.ti.com (157.170.170.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 23 Jan 2024 16:12:29 -0600 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DLEE111.ent.ti.com (157.170.170.22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 23 Jan 2024 16:12:29 -0600 Received: from lelvsmtp6.itg.ti.com ([10.249.42.149]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 40NMCSuS068795; Tue, 23 Jan 2024 16:12:28 -0600 From: Andrew Davis To: Gerd Hoffmann , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , Paul Cercueil CC: , , , , Andrew Davis Subject: [PATCH 1/3] udmabuf: Keep track current device mappings Date: Tue, 23 Jan 2024 16:12:25 -0600 Message-ID: <20240123221227.868341-1-afd@ti.com> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 When a device attaches to and maps our buffer we need to keep track of this mapping/device. This is needed for synchronization with these devices when beginning and ending CPU access for instance. Add a list that tracks device mappings as part of {map,unmap}_udmabuf(). Signed-off-by: Andrew Davis --- drivers/dma-buf/udmabuf.c | 43 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 41 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index c406459996489..3a23f0a7d112a 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -28,6 +28,14 @@ struct udmabuf { struct page **pages; struct sg_table *sg; struct miscdevice *device; + struct list_head attachments; + struct mutex lock; +}; + +struct udmabuf_attachment { + struct device *dev; + struct sg_table *table; + struct list_head list; }; static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) @@ -120,14 +128,42 @@ static void put_sg_table(struct device *dev, struct sg_table *sg, static struct sg_table *map_udmabuf(struct dma_buf_attachment *at, enum dma_data_direction direction) { - return get_sg_table(at->dev, at->dmabuf, direction); + struct udmabuf *ubuf = at->dmabuf->priv; + struct udmabuf_attachment *a; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return ERR_PTR(-ENOMEM); + + a->table = get_sg_table(at->dev, at->dmabuf, direction); + if (IS_ERR(a->table)) { + kfree(a); + return a->table; + } + + a->dev = at->dev; + + mutex_lock(&ubuf->lock); + list_add(&a->list, &ubuf->attachments); + mutex_unlock(&ubuf->lock); + + return a->table; } static void unmap_udmabuf(struct dma_buf_attachment *at, struct sg_table *sg, enum dma_data_direction direction) { - return put_sg_table(at->dev, sg, direction); + struct udmabuf_attachment *a = at->priv; + struct udmabuf *ubuf = at->dmabuf->priv; + + mutex_lock(&ubuf->lock); + list_del(&a->list); + mutex_unlock(&ubuf->lock); + + put_sg_table(at->dev, sg, direction); + + kfree(a); } static void release_udmabuf(struct dma_buf *buf) @@ -263,6 +299,9 @@ static long udmabuf_create(struct miscdevice *device, memfd = NULL; } + INIT_LIST_HEAD(&ubuf->attachments); + mutex_init(&ubuf->lock); + exp_info.ops = &udmabuf_ops; exp_info.size = ubuf->pagecount << PAGE_SHIFT; exp_info.priv = ubuf; From patchwork Tue Jan 23 22:12:26 2024 Content-Type: text/plain; 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Tue, 23 Jan 2024 16:12:29 -0600 From: Andrew Davis To: Gerd Hoffmann , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , Paul Cercueil CC: , , , , Andrew Davis Subject: [PATCH 2/3] udmabuf: Sync buffer mappings for attached devices Date: Tue, 23 Jan 2024 16:12:26 -0600 Message-ID: <20240123221227.868341-2-afd@ti.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240123221227.868341-1-afd@ti.com> References: <20240123221227.868341-1-afd@ti.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Currently this driver creates a SGT table using the CPU as the target device, then performs the dma_sync operations against that SGT. This is backwards to how DMA-BUFs are supposed to behave. This may have worked for the case where these buffers were given only back to the same CPU that produced them as in the QEMU case. And only then because the original author had the dma_sync operations also backwards, syncing for the "device" on begin_cpu. This was noticed and "fixed" in this patch[0]. That then meant we were sync'ing from the CPU to the CPU using a pseudo-device "miscdevice". Which then caused another issue due to the miscdevice not having a proper DMA mask (and why should it, the CPU is not a DMA device). The fix for that was an even more egregious hack[1] that declares the CPU is coherent with itself and can access its own memory space.. Unwind all this and perform the correct action by doing the dma_sync operations for each device currently attached to the backing buffer. [0] commit 1ffe09590121 ("udmabuf: fix dma-buf cpu access") [1] commit 9e9fa6a9198b ("udmabuf: Set the DMA mask for the udmabuf device (v2)") Signed-off-by: Andrew Davis --- drivers/dma-buf/udmabuf.c | 41 +++++++++++++++------------------------ 1 file changed, 16 insertions(+), 25 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 3a23f0a7d112a..ab6764322523c 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -26,8 +26,6 @@ MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is struct udmabuf { pgoff_t pagecount; struct page **pages; - struct sg_table *sg; - struct miscdevice *device; struct list_head attachments; struct mutex lock; }; @@ -169,12 +167,8 @@ static void unmap_udmabuf(struct dma_buf_attachment *at, static void release_udmabuf(struct dma_buf *buf) { struct udmabuf *ubuf = buf->priv; - struct device *dev = ubuf->device->this_device; pgoff_t pg; - if (ubuf->sg) - put_sg_table(dev, ubuf->sg, DMA_BIDIRECTIONAL); - for (pg = 0; pg < ubuf->pagecount; pg++) put_page(ubuf->pages[pg]); kfree(ubuf->pages); @@ -185,33 +179,31 @@ static int begin_cpu_udmabuf(struct dma_buf *buf, enum dma_data_direction direction) { struct udmabuf *ubuf = buf->priv; - struct device *dev = ubuf->device->this_device; - int ret = 0; - - if (!ubuf->sg) { - ubuf->sg = get_sg_table(dev, buf, direction); - if (IS_ERR(ubuf->sg)) { - ret = PTR_ERR(ubuf->sg); - ubuf->sg = NULL; - } - } else { - dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents, - direction); - } + struct udmabuf_attachment *a; - return ret; + mutex_lock(&ubuf->lock); + + list_for_each_entry(a, &ubuf->attachments, list) + dma_sync_sgtable_for_cpu(a->dev, a->table, direction); + + mutex_unlock(&ubuf->lock); + + return 0; } static int end_cpu_udmabuf(struct dma_buf *buf, enum dma_data_direction direction) { struct udmabuf *ubuf = buf->priv; - struct device *dev = ubuf->device->this_device; + struct udmabuf_attachment *a; - if (!ubuf->sg) - return -EINVAL; + mutex_lock(&ubuf->lock); + + list_for_each_entry(a, &ubuf->attachments, list) + dma_sync_sgtable_for_device(a->dev, a->table, direction); + + mutex_unlock(&ubuf->lock); - dma_sync_sg_for_device(dev, ubuf->sg->sgl, ubuf->sg->nents, direction); return 0; } @@ -307,7 +299,6 @@ static long udmabuf_create(struct miscdevice *device, exp_info.priv = ubuf; exp_info.flags = O_RDWR; - ubuf->device = device; buf = dma_buf_export(&exp_info); if (IS_ERR(buf)) { ret = PTR_ERR(buf); From patchwork Tue Jan 23 22:12:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Davis X-Patchwork-Id: 13528207 Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) (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 7FB081A27C; 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Tue, 23 Jan 2024 16:12:30 -0600 Received: from DFLE101.ent.ti.com (10.64.6.22) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 23 Jan 2024 16:12:30 -0600 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE101.ent.ti.com (10.64.6.22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 23 Jan 2024 16:12:29 -0600 Received: from lelvsmtp6.itg.ti.com ([10.249.42.149]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 40NMCSuU068795; Tue, 23 Jan 2024 16:12:29 -0600 From: Andrew Davis To: Gerd Hoffmann , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , Paul Cercueil CC: , , , , Andrew Davis Subject: [PATCH 3/3] udmabuf: Use module_misc_device() to register this device Date: Tue, 23 Jan 2024 16:12:27 -0600 Message-ID: <20240123221227.868341-3-afd@ti.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240123221227.868341-1-afd@ti.com> References: <20240123221227.868341-1-afd@ti.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Now that we do not need to call dma_coerce_mask_and_coherent() on our miscdevice device, use the module_misc_device() helper for registering and module init/exit. Signed-off-by: Andrew Davis Acked-by: Vivek Kasireddy --- drivers/dma-buf/udmabuf.c | 30 +----------------------------- 1 file changed, 1 insertion(+), 29 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index ab6764322523c..3028ac3fd9f6a 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -392,34 +392,6 @@ static struct miscdevice udmabuf_misc = { .name = "udmabuf", .fops = &udmabuf_fops, }; - -static int __init udmabuf_dev_init(void) -{ - int ret; - - ret = misc_register(&udmabuf_misc); - if (ret < 0) { - pr_err("Could not initialize udmabuf device\n"); - return ret; - } - - ret = dma_coerce_mask_and_coherent(udmabuf_misc.this_device, - DMA_BIT_MASK(64)); - if (ret < 0) { - pr_err("Could not setup DMA mask for udmabuf device\n"); - misc_deregister(&udmabuf_misc); - return ret; - } - - return 0; -} - -static void __exit udmabuf_dev_exit(void) -{ - misc_deregister(&udmabuf_misc); -} - -module_init(udmabuf_dev_init) -module_exit(udmabuf_dev_exit) +module_misc_device(udmabuf_misc); MODULE_AUTHOR("Gerd Hoffmann ");