From patchwork Thu May 9 07:20:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10936791 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EFC2E1390 for ; Thu, 9 May 2019 07:20:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D2A7D285B7 for ; Thu, 9 May 2019 07:20:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C28C3289C4; Thu, 9 May 2019 07:20:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C0815285B7 for ; Thu, 9 May 2019 07:20:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=toGydDkEulhs2lreCAsYKdqe7mBmkTR1D3V9TH+NtIs=; b=XD0ob6+WNBKYMD kel6RUixN80Xkf9YIm3ZNjxvE1wEKFh+XWbLDUVNVlXiHUswxXkqytCmdG5Uy/LqbaenkbfWSM1DG 3lWY6uL1YypUlffsE17UOBx88Urmj5W2uWVINMdd1+9ulb9k4nB2cNvoroBfEY7BfXAuUTX4daaeb n2DLpSb+CQYvWX5/eCrCWf3OuFCqtmSu3RX2gPQa185s2MoJciSOZu4T03PLdeL1uoG8t7PclTszp Tq5dkN2vvz4t9rCuXtR0NvqJQVUO/TA+JN/XxZXMKc+xlRcP+lugSQB6mNtUdu9Yr9POghjpdInYv Ha8elXI0mHEpwinHtx8Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hOdMJ-0006A1-CS; Thu, 09 May 2019 07:20:51 +0000 Received: from 089144210233.atnat0019.highway.a1.net ([89.144.210.233] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hOdME-00067H-Jh; Thu, 09 May 2019 07:20:47 +0000 From: Christoph Hellwig To: Russell King Subject: [PATCH] ARM: dma-mapping: don't use the atomic pool for DMA_ATTR_NO_KERNEL_MAPPING Date: Thu, 9 May 2019 09:20:06 +0200 Message-Id: <20190509072006.727-1-hch@lst.de> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP DMA allocations with the DMA_ATTR_NO_KERNEL_MAPPING do not return a kernel virtual address for use in driver, but are expected to be used entirely for userspace mappings and/or device private memory. Because of that we don't need to remap them as uncached, and thus don't need the atomic pool for non-blocking allocations. Note that using the DMA allocator with DMA_ATTR_NO_KERNEL_MAPPING from non-blocking context on a non-coherent device is actually broken without this patch as well, as we feed the address passes to dma_free_attrs directly to the genpool allocator, but for DMA_ATTR_NO_KERNEL_MAPPING allocations it actually contains the address of the first page pointer. Signed-off-by: Christoph Hellwig --- arch/arm/mm/dma-mapping.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index d029fa31624b..f74d824f8fc1 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -706,6 +706,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, pgprot_t prot, bool is_coherent, unsigned long attrs, const void *caller) { + bool want_vaddr = !(attrs & DMA_ATTR_NO_KERNEL_MAPPING); u64 mask = get_coherent_dma_mask(dev); struct page *page = NULL; void *addr; @@ -717,7 +718,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, .gfp = gfp, .prot = prot, .caller = caller, - .want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0), + .want_vaddr = want_vaddr, .coherent_flag = is_coherent ? COHERENT : NORMAL, }; @@ -755,14 +756,14 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, allowblock = gfpflags_allow_blocking(gfp); cma = allowblock ? dev_get_cma_area(dev) : false; - if (cma) + if (!allowblock && !is_coherent && want_vaddr) + buf->allocator = &pool_allocator; + else if (cma) buf->allocator = &cma_allocator; else if (is_coherent) buf->allocator = &simple_allocator; - else if (allowblock) - buf->allocator = &remap_allocator; else - buf->allocator = &pool_allocator; + buf->allocator = &remap_allocator; addr = buf->allocator->alloc(&args, &page);