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 99D7CEEB566 for ; Fri, 8 Sep 2023 19:53:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233117AbjIHTxG (ORCPT ); Fri, 8 Sep 2023 15:53:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240144AbjIHTxF (ORCPT ); Fri, 8 Sep 2023 15:53:05 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAB8A1B0; Fri, 8 Sep 2023 12:52:45 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EEE4C433C8; Fri, 8 Sep 2023 19:52:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694202765; bh=5rqLwj+1myPc2nWRbdfOemy33knRELmmNyhGnJHwvZo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=DLXOAH7QLq3jgJx6Fi/ZAUkSK2MfgRiJ5oVsAuxVowL5jqftZgjx8dnXWti3Hai6+ CyioWdTQJ2heEzrDQQY0d0mJVJB1y6VQWSZAnAH98xinG73Ih4yyadcH6GMyv2vSKe fvFaeCdK3/xO0J3qPx7ad9RjItdEkjkkWRWa5YLXWlvAwTyxh2TEyJYIIJUt4N8Hzh 4k8OS4eRrme6jx45G7s/oUfbO5EUolUkZFgVWbMs/I8twLlWReKt/HOqTSU6KfgYAS 7M0pHlj/YzgYXGbWRPFd0YVHW9mcoFeMfds5t2NJQwiTcYovZaxObFoG2f06T7D4w/ Pr0pM2M/Hn0wA== Date: Fri, 8 Sep 2023 14:52:42 -0500 From: Bjorn Helgaas To: "D M, Sharath Kumar" Cc: "lpieralisi@kernel.org" , "kw@linux.com" , "robh@kernel.org" , "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , "dinguyen@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 1/2] PCI: altera: refactor driver for supporting new platform Message-ID: <20230908195242.GA304243@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Sep 08, 2023 at 01:40:13PM +0000, D M, Sharath Kumar wrote: > > -----Original Message----- > > From: Bjorn Helgaas > > On Fri, Sep 08, 2023 at 09:09:34AM +0000, D M, Sharath Kumar wrote: > > > > -----Original Message----- > > > > From: Bjorn Helgaas ... > > > > > > > + int (*ep_read_cfg)(struct altera_pcie *pcie, u8 busno, > > > > > + unsigned int devfn, int where, int size, u32 *value); > > > > > + int (*ep_write_cfg)(struct altera_pcie *pcie, u8 busno, > > > > > + unsigned int devfn, int where, int size, u32 value); > > > > > > > > "ep_read_cfg" isn't the ideal name because it suggests "endpoint", > > > > but it may be either an endpoint or a switch upstream port. The > > > > rockchip driver uses "other", which isn't super descriptive either but > > might be better. > > > > > > > Ok will change to "nonrp_read_cfg" ? > > > > I think the important point is not whether it's a Root Port or not, but whether > > it's on the root *bus* or not. In other words, I think the driver has to > > determine whether to generate a Type 0 (targeting something on the root > > bus) or a Type 1 (targeting something below a > > bridge) config transaction (see PCI-to-PCI Bridge spec r1.2, sec 3.1.2.1). > > > > There can be non-Root Ports on the root bus, so "nonrp" doesn't seem quite > > right. "Other" would be OK, since that's already used by other drivers. > > Maybe "type0" and "type1" would be better and would fit well with the > > root_bus_nr check you use to distinguish them? > > > Situation is > Root port configuration space - memory mapped > Non root port configuration space - indirect access/proprietary access > Type 0 for devices directly connected to root port > Type 1 for others "mm", "ind"?