From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4397BC433EF for ; Thu, 21 Oct 2021 09:06:39 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0265B60F56 for ; Thu, 21 Oct 2021 09:06:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0265B60F56 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id D49EF60EAC; Thu, 21 Oct 2021 09:06:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vul2t7VGC3MU; Thu, 21 Oct 2021 09:06:37 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id 8786260EA6; Thu, 21 Oct 2021 09:06:37 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 5A89FC001C; Thu, 21 Oct 2021 09:06:37 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 56A16C0011 for ; Thu, 21 Oct 2021 09:06:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 3842383B71 for ; Thu, 21 Oct 2021 09:06:36 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=infradead.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sn9kHSeSXLIr for ; Thu, 21 Oct 2021 09:06:35 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by smtp1.osuosl.org (Postfix) with ESMTPS id 768D183B59 for ; Thu, 21 Oct 2021 09:06:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=NpzWl91iAnav/E2YcIxtE0rgF2ScEmkyj1jmpzMXvK8=; b=z1LJREhWP+/SAkkWw5jbADDMV8 n1QdFeauvo4HeQ+GwhLpamzzqIyItozwlNgUSSjTxfWM5ZyNBwQ3u+7GNvPEJRe/exC/M4rs5tZTs tJC18pqvoSWQuScv/qjK+S39try+I9D4HZsx9czWmJfYIEc3tvjFRP4vONaEdzocRwsjA5NLFciQ0 aoIbVv8QAnKN+XJO8NRyNLl57Fg/n90wlr0dWOpUbSXtJwEDAvVx8Mg4DBJUsT2UREVfNEQAwgiSX i5BLx3OmJ6I6U0Ndbf5KZ3x9reOnHpg1gZnzhmqfB7CMILhTFYrsxJU6pAQNFRS75W46ETQYHdajC KqQCyeAw==; Received: from [2001:4bb8:180:8777:7df0:a8d8:40cc:3310] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mdU1y-006xxB-BI; Thu, 21 Oct 2021 09:06:34 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 06/10] dma-direct: refactor the !coherent checks in dma_direct_alloc Date: Thu, 21 Oct 2021 11:06:07 +0200 Message-Id: <20211021090611.488281-7-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211021090611.488281-1-hch@lst.de> References: <20211021090611.488281-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Cc: Robin Murphy , David Rientjes X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Add a big central !dev_is_dma_coherent(dev) block to deal with as much as of the uncached allocation schemes and document the schemes a bit better. Signed-off-by: Christoph Hellwig --- kernel/dma/direct.c | 58 ++++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 22 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 4ffdb524942a1..d66f37f34ba71 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -196,29 +196,46 @@ void *dma_direct_alloc(struct device *dev, size_t size, !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp); - if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && - !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && - !dev_is_dma_coherent(dev) && - !is_swiotlb_for_alloc(dev)) - return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); + if (!dev_is_dma_coherent(dev)) { + /* + * Fallback to the arch handler if it exists. This should + * eventually go away. + */ + if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && + !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !is_swiotlb_for_alloc(dev)) + return arch_dma_alloc(dev, size, dma_handle, gfp, + attrs); - if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && - !dev_is_dma_coherent(dev)) - return dma_alloc_from_global_coherent(dev, size, dma_handle); + /* + * If there is a global pool, always allocate from it for + * non-coherent devices. + */ + if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL)) + return dma_alloc_from_global_coherent(dev, size, + dma_handle); + + /* + * Otherwise remap if the architecture is asking for it. But + * given that remapping memory is a blocking operation we'll + * instead have to dip into the atomic pools. + */ + if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP)) { + if (!gfpflags_allow_blocking(gfp) && + !is_swiotlb_for_alloc(dev)) + return dma_direct_alloc_from_pool(dev, size, + dma_handle, gfp); + remap = true; + } + } /* - * Remapping or decrypting memory may block. If either is required and - * we can't block, allocate the memory from the atomic pools. - * If restricted DMA (i.e., is_swiotlb_for_alloc) is required, one must - * set up another device coherent pool by shared-dma-pool and use - * dma_alloc_from_dev_coherent instead. + * Decrypting memory may block, so allocate the memory from the atomic + * pools if we can't block. */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - !gfpflags_allow_blocking(gfp) && - (force_dma_unencrypted(dev) || - (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev))) && + force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); @@ -226,10 +243,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); if (!page) return NULL; - - if (!dev_is_dma_coherent(dev) && IS_ENABLED(CONFIG_DMA_DIRECT_REMAP)) { - remap = true; - } else if (PageHighMem(page)) { + if (PageHighMem(page)) { /* * Depending on the cma= arguments and per-arch setup, * dma_alloc_contiguous could return highmem pages. -- 2.30.2 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu