From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiang Liu Subject: Re: [Patch v4 0/8] Consolidate ACPI PCI root common code into ACPI core Date: Thu, 04 Jun 2015 14:41:47 +0800 Message-ID: <556FF32B.9010900@linux.intel.com> References: <1433225576-8215-1-git-send-email-jiang.liu@linux.intel.com> <556F6332.2040501@redhat.com> <556FAFEF.6040802@linux.intel.com> <556FF0AD.6000901@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga11.intel.com ([192.55.52.93]:27015 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752115AbbFDGmK (ORCPT ); Thu, 4 Jun 2015 02:42:10 -0400 In-Reply-To: <556FF0AD.6000901@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Hanjun Guo , Al Stone , "Rafael J . Wysocki" , Bjorn Helgaas , Marc Zyngier , Liviu Dudau , Yijing Wang Cc: Lv Zheng , "lenb @ kernel . org" , LKML , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, "x86 @ kernel . org" , linux-arm-kernel@lists.infradead.org, Mark Salter On 2015/6/4 14:31, Hanjun Guo wrote: > Hi Jiang, >=20 > On 2015=E5=B9=B406=E6=9C=8804=E6=97=A5 09:54, Jiang Liu wrote: >> On 2015/6/4 4:27, Al Stone wrote: >>> On 06/02/2015 12:12 AM, Jiang Liu wrote: >>>> This patch set consolidates common code to support ACPI PCI root o= n x86 >>>> and IA64 platforms into ACPI core, to reproduce duplicated code an= d >>>> simplify maintenance. And a patch set based on this to support ACP= I >>>> based >>>> PCIe host bridge on ARM64 has been posted at: >>> >>> Link is missing (or it's a typo of some flavor). >> HI Al, >> Sorry, I missed the link. It has been posted at: >> https://lkml.org/lkml/2015/5/26/207 >=20 > I failed to get io resources for PCI hostbridge when I was testing P= CI > on ARM64 QEMU, I debugged this for quite a while, and finally found o= ut > that ACPI resource parsing for IO is not suitable for ARM64, because = io > space for x86 is 64K, but 16M for ARM64. >=20 > This issue is only found when the firmware representing the io resour= ce > using the type ACPI_RESOURCE_TYPE_ADDRESS32, so the io address will > greater than 64k. >=20 > In drivers/acpi/resource.c: >=20 > static void acpi_dev_ioresource_flags(struct resource *res, u64 len, > u8 io_decode, u8 translation_ty= pe) > { > res->flags =3D IORESOURCE_IO; >=20 > [...] >=20 > if (res->end >=3D 0x10003) > res->flags |=3D IORESOURCE_DISABLED | IORESOURCE_UNSE= T; >=20 > [...] > } >=20 > so the code will filter out res->end >=3D 0x10003, and in my case, it= will > more than 64K, so we can't get the IO resources. >=20 > I got a question, why we use if (res->end >=3D 0x10003) here? > I mean 64k will be 0x10000, and in that case, we should use > if (res->end >=3D 0x10000) here, not 0x10003, any history behind that= ? Hi Hanjun, This is a special tricky for x86. You may read a dword(four bytes) from IO port 0xffff, so the effective io port space is 0x10003 bytes. >=20 > This is not the problem of this patch set, but need updating > the core ACPI resource parsing code, I'm working on that. I'm > just wondering there is no special IO space on IA64, how this works > on IA64? There is special handling for IO port on IA64. IA64 io ports are actually memory-mapped, and there may be multiple 64K IO port spaces. =46or example, each PCI domain may have its own 64k memory-mapped IO space. Thanks! Gerry >=20 > Thanks > Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html