From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752022AbeEQKRb (ORCPT ); Thu, 17 May 2018 06:17:31 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:33152 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751274AbeEQKR3 (ORCPT ); Thu, 17 May 2018 06:17:29 -0400 Subject: Re: [RFC PATCH] efi/fb: Convert PCI bus address to resource if translated by the bridge To: Sinan Kaya , linux-pci@vger.kernel.org, timur@codeaurora.org Cc: "open list:EFIFB FRAMEBUFFER DRIVER" , Bartlomiej Zolnierkiewicz , linux-arm-msm@vger.kernel.org, open list , "open list:FRAMEBUFFER LAYER" , Peter Jones , linux-arm-kernel@lists.infradead.org References: <1526495029-25783-1-git-send-email-okaya@codeaurora.org> From: Robin Murphy Message-ID: <74ae2347-464c-ddc1-3cb9-f928692e792f@arm.com> Date: Thu, 17 May 2018 11:17:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1526495029-25783-1-git-send-email-okaya@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/05/18 19:23, Sinan Kaya wrote: > A host bridge is allowed to remap BAR addresses using _TRA attribute in > _CRS windows. > > pci_bus 0000:00: root bus resource [mem 0x80100100000-0x8011fffffff window] (bus address [0x00100000-0x1fffffff]) > pci 0000:02:00.0: reg 0x10: [mem 0x8011e000000-0x8011effffff] > > When a VGA device is behind such a host bridge and the resource is > translated efifb driver is trying to do ioremap against bus address > rather than the resource address and is failing to probe. > > efifb driver is having difficulty locating the base address from BAR > address when > > efifb: probing for efifb > efifb: cannot reserve video memory at 0x1e000000 > efifb: framebuffer at 0x1e000000, using 1920k, total 1875k > efifb: mode is 800x600x32, linelength=3200, pages=1 > efifb: scrolling: redraw > efifb: Truecolor: size=8:8:8:8, shift=24:16:8:0 > > Use the host bridge offset information to convert bus address to > resource address in the fixup. > > Signed-off-by: Sinan Kaya > --- > drivers/video/fbdev/efifb.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c > index 46a4484..feef02b 100644 > --- a/drivers/video/fbdev/efifb.c > +++ b/drivers/video/fbdev/efifb.c > @@ -428,6 +428,8 @@ static void efifb_fixup_resources(struct pci_dev *dev) > { > u64 base = screen_info.lfb_base; > u64 size = screen_info.lfb_size; > + struct pci_host_bridge *bridge; > + struct resource_entry *window; > int i; > > if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI) > @@ -439,6 +441,27 @@ static void efifb_fixup_resources(struct pci_dev *dev) > if (!base) > return; > > + bridge = pci_find_host_bridge(dev->bus); > + if (!bridge) > + return; > + > + resource_list_for_each_entry(window, &bridge->windows) { > + phys_addr_t win_start; > + phys_addr_t win_end; > + size_t win_size; > + > + if (resource_type(window->res) != IORESOURCE_MEM) > + continue; > + > + win_start = window->res->start - window->offset; > + win_end = window->res->end - window->offset; > + win_size = window->res->end - window->res->start + 1; > + if (win_start <= base && win_end >= base + win_size - 1) { > + base += window->offset; > + break; > + } > + } > + Is this not pretty much just pcibios_bus_to_resource()? Robin. > for (i = 0; i <= PCI_STD_RESOURCE_END; i++) { > struct resource *res = &dev->resource[i]; > >