From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 146B3C43217 for ; Wed, 4 May 2022 12:38:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349814AbiEDMmW (ORCPT ); Wed, 4 May 2022 08:42:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349822AbiEDMmS (ORCPT ); Wed, 4 May 2022 08:42:18 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4376233A3B; Wed, 4 May 2022 05:38:36 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id 6A2FD92009C; Wed, 4 May 2022 14:38:35 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 5C9E092009B; Wed, 4 May 2022 13:38:35 +0100 (BST) Date: Wed, 4 May 2022 13:38:35 +0100 (BST) From: "Maciej W. Rozycki" To: Arnd Bergmann cc: Bjorn Helgaas , Niklas Schnelle , Arnd Bergmann , Greg Kroah-Hartman , Linux Kernel Mailing List , linux-arch , linux-pci , Dominik Brodowski Subject: Re: [RFC v2 25/39] pcmcia: add HAS_IOPORT dependencies In-Reply-To: Message-ID: References: <20220429135108.2781579-44-schnelle@linux.ibm.com> <20220503233802.GA420374@bhelgaas> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 May 2022, Arnd Bergmann wrote: > Almost all architectures that support CONFIG_PCI also provide > HAS_IOPORT today (at least at compile time, if not at runtime), > with s390 as a notable exception. Any machines that have legacy > PCI device support will also have I/O ports because a lot of > legacy PCI cards used it, and any machine with a pc-card slot > should also support legacy PCI devices. > > If we get new architectures without I/O space in the future, they > would certainly not care about supporting old cardbus devices. POWER9 is another architecture with no port I/O space[1]: Table 3-2. PCIe TLP command summary -----------+-----------------------------+------------------------------- Class | Type Name | Notes ===========+=============================+=============================== Completion | Completion without Data | For PCI CFG Writes (nonposted) | | or for error responses. Completion | Completion with Data | CI load responses. Nonposted | Configuration Read Request | Outbound only. Nonposted | Configuration Write Request | Outbound only. Posted | Message Request | Inbound only. Nonposted | Memory Read Request | Posted | Memory Write Request | ===========+=============================+=============================== 1. All other valid PCIe command types are ignored and dropped. 2. Invalid PCIe request command types will result in a completion response of Unsupported Request. ------------------------------------+------------------------------------ that we do support -- I have such a system. And I guess POWER10 is the same, as will be all future architecture updates. References: [1] "Power Systems Host Bridge 4 (PHB4) Specification", Version 1.0, International Business Machines Corporation, 27 July 2018, Section 3.1 "PHB4 Command Details", p.29 Maciej