From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de ([217.72.192.75]:51350 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751809AbcGOG4h (ORCPT ); Fri, 15 Jul 2016 02:56:37 -0400 From: Arnd Bergmann To: Bharat Kumar Gogada Cc: Lorenzo Pieralisi , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Bjorn Helgaas , "Liviu.Dudau@arm.com" , nofooter , "thomas.petazzoni@free-electrons.com" , Rongrong Zou , Rongrong Zou , linux-arm-kernel@lists.infradead.org Subject: Re: Purpose of pci_remap_iospace Date: Fri, 15 Jul 2016 08:55:46 +0200 Message-ID: <4711052.Qi2htfK0nU@wuerfel> In-Reply-To: <8520D5D51A55D047800579B094147198258B92E9@XAP-PVEXMBX01.xlnx.xilinx.com> References: <8520D5D51A55D047800579B094147198258B85DC@XAP-PVEXMBX01.xlnx.xilinx.com> <20160714145624.GB30657@red-moon> <8520D5D51A55D047800579B094147198258B92E9@XAP-PVEXMBX01.xlnx.xilinx.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-pci-owner@vger.kernel.org List-ID: On Friday, July 15, 2016 5:21:20 AM CEST Bharat Kumar Gogada wrote: > > On Thu, Jul 14, 2016 at 01:32:13PM +0000, Bharat Kumar Gogada wrote: > > > > [...] > > > > > Hi Lorenzo, > > > > > > I missed something in my device tree now I corrected it. > > > > > > ranges = <0x01000000 0x00000000 0xe0000000 0x00000000 0xe0000000 0 > > 0x00010000 //io > > > > You have not missed anything, you changed the PCI bus address at which > > your host bridge responds to IO space and it must match your configuration. > > At what PCI bus address your host bridge maps IO space ? > > > Our host bridge does not have dedicted address space mapped for IO transactions. > For generation of IO transactions it requires some register read and write operations > in bridge logic. > > So the above PCI address does not come in to picture also, is there alternate way to handle IO > Bars with our kind of hardware architecture. Hisilicon has a similar thing on one of their LPC bridges, and Rongrong Zou has implemented something for it in the past, but I think it never got merged. https://lkml.org/lkml/2015/12/29/154 has one version of his proposal, not sure if that was the latest one or if something newer exists. Arnd