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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 059D3C282DA for ; Wed, 17 Apr 2019 20:12:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33B0820651 for ; Wed, 17 Apr 2019 20:12:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555531956; bh=Mo5WVNMnafU6YX4w6aBTS2+7npoANQF42AZYIZO8WMs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=PyWRPLGB8tZ49Vuu379841mMKHuRrEvWNquXw/9ftEKQq0uq+eY1dN20mwup26HK0 N32dvsU+snSRnWia0yBSjoyk3yNU3V+L0kPJhpCP+8rG/iN3DPVkTa+m9mcuL6o2k6 NChvxInScCnTuTtkeI6Ft8AQJDEjODo1GhICI9s0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731030AbfDQUMf (ORCPT ); Wed, 17 Apr 2019 16:12:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:36474 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfDQUMe (ORCPT ); Wed, 17 Apr 2019 16:12:34 -0400 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2F82B20651; Wed, 17 Apr 2019 20:12:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555531953; bh=Mo5WVNMnafU6YX4w6aBTS2+7npoANQF42AZYIZO8WMs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fGMRy6KihRFj/gkZMyd9mZ4HZ+GNtpgT0gH97XupSfhMLpIOroCMQMpc807ZMEgo5 1fs/RGNzmWGLsv3ESzAigwOnX3NOkuL6pzyG22qvY8zK1xhPITVb3eDerCan15idio xpfEUnqy62w7nAS+wdYnu6aN8Yb+aepXkNVXRyjM= Date: Wed, 17 Apr 2019 15:12:32 -0500 From: Bjorn Helgaas To: sundeep.lkml@gmail.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, sean.stalley@intel.com, sgoutham@marvell.com, Subbaraya Sundeep Subject: Re: [v3 PATCH 1/2] PCI: read fixed bus numbers in EA for type 1 functions Message-ID: <20190417201232.GQ126710@google.com> References: <1548249481-24645-1-git-send-email-sundeep.lkml@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1548249481-24645-1-git-send-email-sundeep.lkml@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 23, 2019 at 06:48:00PM +0530, sundeep.lkml@gmail.com wrote: > From: Subbaraya Sundeep > > As per the spec - ECN_Enhanced_Allocation_23_Oct_2014_Final > and section 6.9.1.2, EA capability contains fixed secondary > and subordinate bus numbers for type 1 functions. > This patch adds support to read the fixed bus numbers > from EA capability for bridge. > > Signed-off-by: Subbaraya Sundeep > --- > v3: > As per Bjorn's suggestion placed EA stuff in pci_ea_init and > captured bus numbers in pci_dev You were right the first time, and my idea of putting this stuff in pci_ea_init() was well-intentioned but wrong. It doesn't seem worthwhile to add those two fields to pci_dev when they will almost always be unused. I applied your v2 patch and revised it a little; I'll respond to that patch so the comments make sense there. > v2: > None just added Sean > > drivers/pci/pci.c | 10 ++++++++-- > include/linux/pci.h | 4 ++++ > include/uapi/linux/pci_regs.h | 4 ++++ > 3 files changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index c25acac..484b63e 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -2909,6 +2909,7 @@ void pci_ea_init(struct pci_dev *dev) > u8 num_ent; > int offset; > int i; > + u32 dw; > > /* find PCI EA capability in list */ > ea = pci_find_capability(dev, PCI_CAP_ID_EA); > @@ -2922,9 +2923,14 @@ void pci_ea_init(struct pci_dev *dev) > > offset = ea + PCI_EA_FIRST_ENT; > > - /* Skip DWORD 2 for type 1 functions */ > - if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) > + /* Note fixed bus numbers for type 1 functions */ > + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { > + pci_read_config_dword(dev, offset, &dw); > + dev->fixed_sec_busnr = dw & PCI_EA_FIXED_SEC_BUS; > + dev->fixed_sub_busnr = (dw & PCI_EA_FIXED_SUB_BUS) >> > + PCI_EA_FIXED_SUB_SHIFT; > offset += 4; > + } > > /* parse each EA entry */ > for (i = 0; i < num_ent; ++i) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 65f1d8c..3e9a3ae 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -459,6 +459,10 @@ struct pci_dev { > char *driver_override; /* Driver name to force a match */ > > unsigned long priv_flags; /* Private flags for the PCI driver */ > + > + /* bus numbers from EA capability if this device is a bridge */ > + u8 fixed_sec_busnr; /* Fixed Secondary Bus number */ > + u8 fixed_sub_busnr; /* Fixed Subordinate Bus number */ > }; > > static inline struct pci_dev *pci_physfn(struct pci_dev *dev) > diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h > index e1e9888..51e9ac0 100644 > --- a/include/uapi/linux/pci_regs.h > +++ b/include/uapi/linux/pci_regs.h > @@ -372,6 +372,10 @@ > #define PCI_EA_FIRST_ENT_BRIDGE 8 /* First EA Entry for Bridges */ > #define PCI_EA_ES 0x00000007 /* Entry Size */ > #define PCI_EA_BEI 0x000000f0 /* BAR Equivalent Indicator */ > +/* Fixed Secondary and Subordinate bus numbers in EA for Bridge */ > +#define PCI_EA_FIXED_SEC_BUS 0xff > +#define PCI_EA_FIXED_SUB_BUS 0xff00 > +#define PCI_EA_FIXED_SUB_SHIFT 8 > /* 0-5 map to BARs 0-5 respectively */ > #define PCI_EA_BEI_BAR0 0 > #define PCI_EA_BEI_BAR5 5 > -- > 1.8.3.1 >