From patchwork Sat Nov 21 04:49:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 330164 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64958C64E7C for ; Sat, 21 Nov 2020 04:50:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D75521D46 for ; Sat, 21 Nov 2020 04:50:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="xlZ1IdHn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727030AbgKUEuH (ORCPT ); Fri, 20 Nov 2020 23:50:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726862AbgKUEuG (ORCPT ); Fri, 20 Nov 2020 23:50:06 -0500 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2C2DC0613CF for ; Fri, 20 Nov 2020 20:50:06 -0800 (PST) Received: by mail-pg1-x542.google.com with SMTP id 34so9130142pgp.10 for ; Fri, 20 Nov 2020 20:50:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8/ixTvQ2Zry3DTCO/KoZEMuJmBTKPEtfwzNBsOWjMeg=; b=xlZ1IdHnHFgs60OV/DrQAPIpBOgEvNLTm6jmy1ckIJf+cd/nnZGdo88FLHtPv0Cu20 AhBIou4c8XuzhWUYe9EDB9kG6cXQI3vFgprETVjkuBXALH/fU1668D9lU57dtwkR8+/6 7TiBM25khO78i/3MnBV6qW84iMcurAueKzm3bU6DfHlyMVQp5XtcLob1wtLeqhMFkyAI RTqIA88Xd2y75Es/9d1115o6t8tOmxvzFb5K/P6azp2M9yILYk1VvHsmasBX+Wd7WvC0 vzrpYG2QdEA67Hd+TF8oyaB7kFcscr/9Mp8iXFETo3WP56YOj6UQnG9jsTZKoIjMIh0c 7b2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=8/ixTvQ2Zry3DTCO/KoZEMuJmBTKPEtfwzNBsOWjMeg=; b=hHB9jQGYXg08fnf6V7uDuoQpDzt9AKtK8o/LtfW4sQgpS19sCRR9VNMaKMBUOsAL7Q VBiA0FDeD983AUtBpc9KKrR7uJDKvTsHZsypWVj5OynFdgYdivABPWqbBONOBYQjG9h6 RHtxlOT/GuRGXAfhSW/BwF3geSXDhrKJW+vvxHESs9pziayJ4XdtOI+vKyyCEyj90FTm uFyAu8q0kiniPwRz8yiMcTtdMJYukvHEoSridB4daepypPbW32UP4ZGzjrCQ3PRcPSWz qbYyo71vbofxCMFAMPZYW3RYS2bllE5l3uT1hj0d1Ac9h43roa1Obu4ZgyOMmTY+lJxR /MCQ== X-Gm-Message-State: AOAM530pxepHsk1uka4PxaQilpCvwS+8q7UbMy7MKuUpYaUkU8XoYmMm IcJcpT+S2VazA0aONH2T2PbbUQ== X-Google-Smtp-Source: ABdhPJwkbIJx1k7xwrwwZK1EOfFVXpyarTDc/2XPaSAXtqk+Jnn/+DQIoqGFTNjhmRjDWU1ZphKyhA== X-Received: by 2002:aa7:8801:0:b029:18b:5878:30d6 with SMTP id c1-20020aa788010000b029018b587830d6mr17144282pfo.77.1605934206209; Fri, 20 Nov 2020 20:50:06 -0800 (PST) Received: from localhost.localdomain ([2601:1c2:680:1319:692:26ff:feda:3a81]) by smtp.gmail.com with ESMTPSA id w196sm5407692pfd.177.2020.11.20.20.50.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Nov 2020 20:50:05 -0800 (PST) From: John Stultz To: lkml Cc: John Stultz , Sumit Semwal , Liam Mark , Laura Abbott , Brian Starkey , Hridya Valsaraju , Suren Baghdasaryan , Sandeep Patil , Daniel Mentz , Chris Goldsworthy , =?utf-8?q?=C3=98rjan_Eide?= , Robin Murphy , Ezequiel Garcia , Simon Ser , James Jones , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH v6 4/5] dma-buf: heaps: Skip sync if not mapped Date: Sat, 21 Nov 2020 04:49:54 +0000 Message-Id: <20201121044955.58215-5-john.stultz@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201121044955.58215-1-john.stultz@linaro.org> References: <20201121044955.58215-1-john.stultz@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This patch is basically a port of Ørjan Eide's similar patch for ION https://lore.kernel.org/lkml/20200414134629.54567-1-orjan.eide@arm.com/ Only sync the sg-list of dma-buf heap attachment when the attachment is actually mapped on the device. dma-bufs may be synced at any time. It can be reached from user space via DMA_BUF_IOCTL_SYNC, so there are no guarantees from callers on when syncs may be attempted, and dma_buf_end_cpu_access() and dma_buf_begin_cpu_access() may not be paired. Since the sg_list's dma_address isn't set up until the buffer is used on the device, and dma_map_sg() is called on it, the dma_address will be NULL if sync is attempted on the dma-buf before it's mapped on a device. Before v5.0 (commit 55897af63091 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code")) this was a problem as the dma-api (at least the swiotlb_dma_ops on arm64) would use the potentially invalid dma_address. How that failed depended on how the device handled physical address 0. If 0 was a valid address to physical ram, that page would get flushed a lot, while the actual pages in the buffer would not get synced correctly. While if 0 is an invalid physical address it may cause a fault and trigger a crash. In v5.0 this was incidentally fixed by commit 55897af63091 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code"), as this moved the dma-api to use the page pointer in the sg_list, and (for Ion buffers at least) this will always be valid if the sg_list exists at all. But, this issue is re-introduced in v5.3 with commit 449fa54d6815 ("dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device") moves the dma-api back to the old behaviour and picks the dma_address that may be invalid. dma-buf core doesn't ensure that the buffer is mapped on the device, and thus have a valid sg_list, before calling the exporter's begin_cpu_access. Logic and commit message originally by: Ørjan Eide Cc: Sumit Semwal Cc: Liam Mark Cc: Laura Abbott Cc: Brian Starkey Cc: Hridya Valsaraju Cc: Suren Baghdasaryan Cc: Sandeep Patil Cc: Daniel Mentz Cc: Chris Goldsworthy Cc: Ørjan Eide Cc: Robin Murphy Cc: Ezequiel Garcia Cc: Simon Ser Cc: James Jones Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Brian Starkey Signed-off-by: John Stultz --- drivers/dma-buf/heaps/cma_heap.c | 10 ++++++++++ drivers/dma-buf/heaps/system_heap.c | 10 ++++++++++ 2 files changed, 20 insertions(+) diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 52459f3e60e2..2b468767a2af 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -43,6 +43,7 @@ struct dma_heap_attachment { struct device *dev; struct sg_table table; struct list_head list; + bool mapped; }; static int cma_heap_attach(struct dma_buf *dmabuf, @@ -67,6 +68,7 @@ static int cma_heap_attach(struct dma_buf *dmabuf, a->dev = attachment->dev; INIT_LIST_HEAD(&a->list); + a->mapped = false; attachment->priv = a; @@ -101,6 +103,7 @@ static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachme ret = dma_map_sgtable(attachment->dev, table, direction, 0); if (ret) return ERR_PTR(-ENOMEM); + a->mapped = true; return table; } @@ -108,6 +111,9 @@ static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, enum dma_data_direction direction) { + struct dma_heap_attachment *a = attachment->priv; + + a->mapped = false; dma_unmap_sgtable(attachment->dev, table, direction, 0); } @@ -122,6 +128,8 @@ static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, mutex_lock(&buffer->lock); list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; dma_sync_sgtable_for_cpu(a->dev, &a->table, direction); } mutex_unlock(&buffer->lock); @@ -140,6 +148,8 @@ static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, mutex_lock(&buffer->lock); list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; dma_sync_sgtable_for_device(a->dev, &a->table, direction); } mutex_unlock(&buffer->lock); diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index e5f9f964b910..b1a7b355132f 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -37,6 +37,7 @@ struct dma_heap_attachment { struct device *dev; struct sg_table *table; struct list_head list; + bool mapped; }; static struct sg_table *dup_sg_table(struct sg_table *table) @@ -84,6 +85,7 @@ static int system_heap_attach(struct dma_buf *dmabuf, a->table = table; a->dev = attachment->dev; INIT_LIST_HEAD(&a->list); + a->mapped = false; attachment->priv = a; @@ -120,6 +122,7 @@ static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attac if (ret) return ERR_PTR(ret); + a->mapped = true; return table; } @@ -127,6 +130,9 @@ static void system_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, enum dma_data_direction direction) { + struct dma_heap_attachment *a = attachment->priv; + + a->mapped = false; dma_unmap_sgtable(attachment->dev, table, direction, 0); } @@ -142,6 +148,8 @@ static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, invalidate_kernel_vmap_range(buffer->map->vaddr, buffer->len); list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; dma_sync_sgtable_for_cpu(a->dev, a->table, direction); } mutex_unlock(&buffer->lock); @@ -161,6 +169,8 @@ static int system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, flush_kernel_vmap_range(buffer->map->vaddr, buffer->len); list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; dma_sync_sgtable_for_device(a->dev, a->table, direction); } mutex_unlock(&buffer->lock);