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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C0AF5C352A3 for ; Mon, 10 Feb 2020 13:03:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9862E2070A for ; Mon, 10 Feb 2020 13:03:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581339828; bh=8ZdGH4cViKER73J86CwWEW5+ohT/R9M7TtH64Uwyo78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1dye7xtDU/6nCxQ0y0xbH9fHqI17EhCB1NtOMd8ph5OeRoSFYl/nuVl9nwFrynY5o 5Q8tBRspvt4VB1DJIcokozedAjbEgNr0mIB93iA4/9O7GuC3TosJLcZ7W1z40Nsalu ixgKlvMWB/WjNSoPBC/LDZCG1iM8WCc2b4FNlWYg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730408AbgBJNDq (ORCPT ); Mon, 10 Feb 2020 08:03:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:40240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729711AbgBJMkV (ORCPT ); Mon, 10 Feb 2020 07:40:21 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CDFA821739; Mon, 10 Feb 2020 12:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338420; bh=8ZdGH4cViKER73J86CwWEW5+ohT/R9M7TtH64Uwyo78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q4CncrExImbTniJ1PXkEJFrLQaGDMa8YxtOa4QyaFC0brQ/Inw3sOc66P/jxc8C4I NrGZbyAvxyM6rwWpEI7F0G7+22Tfrvv/KO5pgGifYjqyZADF5tVhB2AJtqmasM6dYc ZekzxeXsniAFBB+VYH9tCY74ttax6W2oi6GpsjEA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen-Yu Tsai , Christoph Hellwig , Russell King , Robin Murphy , Andrew Morton , Linus Torvalds Subject: [PATCH 5.5 139/367] ARM: dma-api: fix max_pfn off-by-one error in __dma_supported() Date: Mon, 10 Feb 2020 04:30:52 -0800 Message-Id: <20200210122437.679718067@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chen-Yu Tsai commit f3cc4e1d44a813a0685f2e558b78ace3db559722 upstream. max_pfn, as set in arch/arm/mm/init.c: static void __init find_limits(unsigned long *min, unsigned long *max_low, unsigned long *max_high) { *max_low = PFN_DOWN(memblock_get_current_limit()); *min = PFN_UP(memblock_start_of_DRAM()); *max_high = PFN_DOWN(memblock_end_of_DRAM()); } with memblock_end_of_DRAM() pointing to the next byte after DRAM. As such, max_pfn points to the PFN after the end of DRAM. Thus when using max_pfn to check DMA masks, we should subtract one when checking DMA ranges against it. Commit 8bf1268f48ad ("ARM: dma-api: fix off-by-one error in __dma_supported()") fixed the same issue, but missed this spot. This issue was found while working on the sun4i-csi v4l2 driver on the Allwinner R40 SoC. On Allwinner SoCs, DRAM is offset at 0x40000000, and we are starting to use of_dma_configure() with the "dma-ranges" property in the device tree to have the DMA API handle the offset. In this particular instance, dma-ranges was set to the same range as the actual available (2 GiB) DRAM. The following error appeared when the driver attempted to allocate a buffer: sun4i-csi 1c09000.csi: Coherent DMA mask 0x7fffffff (pfn 0x40000-0xc0000) covers a smaller range of system memory than the DMA zone pfn 0x0-0xc0001 sun4i-csi 1c09000.csi: dma_alloc_coherent of size 307200 failed Fixing the off-by-one error makes things work. Link: http://lkml.kernel.org/r/20191224030239.5656-1-wens@kernel.org Fixes: 11a5aa32562e ("ARM: dma-mapping: check DMA mask against available memory") Fixes: 9f28cde0bc64 ("ARM: another fix for the DMA mapping checks") Fixes: ab746573c405 ("ARM: dma-mapping: allow larger DMA mask than supported") Signed-off-by: Chen-Yu Tsai Reviewed-by: Christoph Hellwig Cc: Russell King Cc: Robin Murphy Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -221,7 +221,7 @@ EXPORT_SYMBOL(arm_coherent_dma_ops); static int __dma_supported(struct device *dev, u64 mask, bool warn) { - unsigned long max_dma_pfn = min(max_pfn, arm_dma_pfn_limit); + unsigned long max_dma_pfn = min(max_pfn - 1, arm_dma_pfn_limit); /* * Translate the device's DMA mask to a PFN limit. This