From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 07 Nov 2018 01:10:08 +0100 (CET) Received: (from localhost user: 'macro', uid#1010) by eddie.linux-mips.org with ESMTP id S23991112AbeKGAIQRanZY (ORCPT ); Wed, 7 Nov 2018 01:08:16 +0100 Date: Wed, 7 Nov 2018 00:08:16 +0000 (GMT) From: "Maciej W. Rozycki" To: Ralf Baechle , Paul Burton cc: Christoph Hellwig , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] MIPS: SiByte: Handle PCI DMA with 64-bit memory addressing Message-ID: User-Agent: Alpine 2.21 (LFD 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 67112 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: macro@linux-mips.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Hi, This mini patch series enables correct support for DMA in the presence of memory outside the 32-bit address range with the Broadcom SiByte SOCs and the relevant development boards. There is a quirk in the BCM1250, BCM1125 and BCM1125H SOCs in that their onchip 32-bit PCI host bridge does not support DAC, however the HT link (where available) does support 40-bit addressing as per the HT spec. Therefore the first patch sets the bus mask accordingly, and then the second patch enables swiotlb. See individual change descriptions for additional details; there's also a further discussion alongside. This has been verified with a Broadcom SWARM board equipped with 3200MiB of RAM (2176MiB of which the address decoder in the SOC maps above 4GiB), a pair of DEFPA FDDI adapters and an XHCI USB adapter. There were also some other PCI and PCIe devices present in the system, though not actively used beyond being probed at boot, and none has shown any symptoms of breakage. Thanks to Christoph for making this change so easy with his recent work! Please apply. Maciej