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 X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 71D5FC7618F for ; Wed, 17 Jul 2019 15:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 541EE2173B for ; Wed, 17 Jul 2019 15:31:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728034AbfGQPbt (ORCPT ); Wed, 17 Jul 2019 11:31:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:43448 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727803AbfGQPbs (ORCPT ); Wed, 17 Jul 2019 11:31:48 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id EB414B048; Wed, 17 Jul 2019 15:31:46 +0000 (UTC) From: Nicolas Saenz Julienne To: linux-arm-kernel@lists.infradead.org, Christoph Hellwig , Marek Szyprowski , Robin Murphy Cc: catalin.marinas@arm.com, will@kernel.org, phil@raspberrypi.org, stefan.wahren@i2se.com, f.fainelli@gmail.com, mbrugger@suse.com, Jisheng.Zhang@synaptics.com, Nicolas Saenz Julienne , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [RFC 3/4] dma-direct: add dma_direct_min_mask Date: Wed, 17 Jul 2019 17:31:34 +0200 Message-Id: <20190717153135.15507-4-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190717153135.15507-1-nsaenzjulienne@suse.de> References: <20190717153135.15507-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Historically devices with ZONE_DMA32 have been assumed to be able to address at least the lower 4GB of ram for DMA. This is still the defualt behavior yet the Raspberry Pi 4 is limited to the first GB of memory. This has been observed to trigger failures in dma_direct_supported() as the 'min_mask' isn't properly set. We create 'dma_direct_min_mask' in order for the arch init code to be able to fine-tune dma direct's 'min_dma' mask. Signed-off-by: Nicolas Saenz Julienne --- kernel/dma/direct.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index b90e1aede743..3c8cd730648b 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -23,6 +23,8 @@ #define ARCH_ZONE_DMA_BITS 24 #endif +u64 dma_direct_min_mask __ro_after_init = DMA_BIT_MASK(32); + /* * For AMD SEV all DMA must be to unencrypted addresses. */ @@ -393,7 +395,7 @@ int dma_direct_supported(struct device *dev, u64 mask) if (IS_ENABLED(CONFIG_ZONE_DMA)) min_mask = DMA_BIT_MASK(ARCH_ZONE_DMA_BITS); else - min_mask = DMA_BIT_MASK(32); + min_mask = dma_direct_min_mask; min_mask = min_t(u64, min_mask, (max_pfn - 1) << PAGE_SHIFT); -- 2.22.0