Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751503AbdFFWPc (ORCPT ); Tue, 6 Jun 2017 18:15:32 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:47320 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398AbdFFWPb (ORCPT ); Tue, 6 Jun 2017 18:15:31 -0400 Subject: Re: [PATCH v4] hsdk: initial port for HSDK board To: Alexey Brodkin , CC: , Eugeniy Paltsev , Rob Herring Newsgroups: gmane.linux.kernel,gmane.linux.kernel.arc References: <1496692249-11699-1-git-send-email-abrodkin@synopsys.com> From: Vineet Gupta Message-ID: Date: Tue, 6 Jun 2017 15:15:10 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <1496692249-11699-1-git-send-email-abrodkin@synopsys.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.161.108] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1618 Lines: 34 On 06/05/2017 12:50 PM, Alexey Brodkin wrote: > This initial port adds support of ARC HS Development Kit board with some > basic features such serial port, USB, SD/MMC and Ethernet. > > Essentially we run Linux kernel on all 4 cores (i.e. utilize SMP) and > heavily use IO Coherency for speeding-up DMA-aware peripherals. > > Note as opposed to other ARC boards we link Linux kernel to > 0x9000_0000 intentionally because cores 1 and 3 configured with DCCM > situated at our more usual link base 0x8000_0000. > > Signed-off-by: Eugeniy Paltsev > Signed-off-by: Alexey Brodkin > Cc: Vineet Gupta > Cc: Rob Herring > --- > > Changes v3 -> v4: > * Removed senseless "ranges" property from "memory" node in .dts > * Refined early-boot code: > - CREG_PAE should be set only once thus master does that in init_early() > - ICCM relocation should be done on each and every core that sports ICCM > so we leave it in init_per_cpu(). Even though init_per_cpu() gets called > on the master core pretty late still it is way much earlier than that > moment when it might affect us - as it only huts us when addresses in > 0x7z-0x7fff_ffff range are used, i.e. virtual addresses that we don't > use during init. This also makes code much cleaner compared to > additional check in case of master etc. So you are assuming that vmalloc machinery would not have kicked in by then i.e. by the time of irq_init() i.e. - perhaps that is true. Lets go with what you have now.... -Vineet