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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 08DB1C433E4 for ; Mon, 27 Jul 2020 10:50:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4F4B2083E for ; Mon, 27 Jul 2020 10:50:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728311AbgG0Ku6 (ORCPT ); Mon, 27 Jul 2020 06:50:58 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2531 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726298AbgG0Ku5 (ORCPT ); Mon, 27 Jul 2020 06:50:57 -0400 Received: from lhreml710-chm.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id C5BEAD530574697C489D; Mon, 27 Jul 2020 11:50:55 +0100 (IST) Received: from localhost (10.52.121.176) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1913.5; Mon, 27 Jul 2020 11:50:55 +0100 Date: Mon, 27 Jul 2020 11:49:32 +0100 From: Jonathan Cameron To: Sean V Kelley CC: , , , , , , , Qiuxu Zhuo Subject: Re: [RFC PATCH 3/9] PCI/portdrv: Add pcie_walk_rcec() to walk RCiEPs associated with RCEC Message-ID: <20200727114932.00002c33@Huawei.com> In-Reply-To: <20200724172223.145608-4-sean.v.kelley@intel.com> References: <20200724172223.145608-1-sean.v.kelley@intel.com> <20200724172223.145608-4-sean.v.kelley@intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.121.176] X-ClientProxiedBy: lhreml704-chm.china.huawei.com (10.201.108.53) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, 24 Jul 2020 10:22:17 -0700 Sean V Kelley wrote: > From: Qiuxu Zhuo > > When an RCEC device signals error(s) to a CPU core, the CPU core > needs to walk all the RCiEPs associated with that RCEC to check > errors. So add the function pcie_walk_rcec() to walk all RCiEPs > associated with the RCEC device. > > Co-developed-by: Sean V Kelley > Signed-off-by: Qiuxu Zhuo > Signed-off-by: Sean V Kelley A few trivial points inline. With those tidied up. Reviewed-by: Jonathan Cameron > --- > drivers/pci/pcie/portdrv.h | 2 + > drivers/pci/pcie/portdrv_core.c | 82 +++++++++++++++++++++++++++++++++ > 2 files changed, 84 insertions(+) > > diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h > index af7cf237432a..c11d5ecbad76 100644 > --- a/drivers/pci/pcie/portdrv.h > +++ b/drivers/pci/pcie/portdrv.h > @@ -116,6 +116,8 @@ void pcie_port_service_unregister(struct pcie_port_service_driver *new); > > extern struct bus_type pcie_port_bus_type; > int pcie_port_device_register(struct pci_dev *dev); > +void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev *, void *), > + void *userdata); > #ifdef CONFIG_PM > int pcie_port_device_suspend(struct device *dev); > int pcie_port_device_resume_noirq(struct device *dev); > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > index 50a9522ab07d..bdcbb34764c2 100644 > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > > #include "../pci.h" > @@ -365,6 +366,87 @@ int pcie_port_device_register(struct pci_dev *dev) > return status; > } > > +static int pcie_walk_rciep_devfn(struct pci_bus *pbus, int (*cb)(struct pci_dev *, void *), > + void *userdata, unsigned long bitmap) > +{ > + unsigned int dev, fn; > + struct pci_dev *pdev; > + int retval; > + > + for_each_set_bit(dev, &bitmap, 32) { > + for (fn = 0; fn < 8; fn++) { > + pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn)); > + > + if (!pdev || pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_END) > + continue; > + > + retval = cb(pdev, userdata); > + if (retval) > + return retval; > + } > + } > + > + return 0; > +} > + > +/** pcie_walk_rcec - Walk RCiEP devices associating with RCEC and call callback. /** * pcie... > + * @rcec RCEC whose RCiEP devices should be walked. > + * @cb Callback to be called for each RCiEP device found. > + * @userdata Arbitrary pointer to be passed to callback. > + * > + * Walk the given RCEC. Call the provided callback on each RCiEP device found. > + * > + * We check the return of @cb each time. If it returns anything > + * other than 0, we break out. > + * > + */ > +void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev *, void *), > + void *userdata) > +{ > + u32 pos, bitmap, hdr, busn; > + u8 ver, nextbusn, lastbusn; > + struct pci_bus *pbus; > + unsigned int bnr; > + > + pos = pci_find_ext_capability(rcec, PCI_EXT_CAP_ID_RCEC); > + if (!pos) > + return; > + > + pbus = pci_find_bus(pci_domain_nr(rcec->bus), rcec->bus->number); > + if (!pbus) > + return; > + > + pci_read_config_dword(rcec, pos + PCI_RCEC_RCIEP_BITMAP, &bitmap); > + > + /* Find RCiEP devices on the same bus as the RCEC */ > + if (pcie_walk_rciep_devfn(pbus, cb, userdata, (unsigned long)bitmap)) > + return; > + > + /* Check whether RCEC BUSN register is present */ > + pci_read_config_dword(rcec, pos, &hdr); > + ver = PCI_EXT_CAP_VER(hdr); > + if (ver < PCI_RCEC_BUSN_REG_VER) > + return; > + > + pci_read_config_dword(rcec, pos + PCI_RCEC_BUSN, &busn); > + nextbusn = PCI_RCEC_BUSN_NEXT(busn); > + lastbusn = PCI_RCEC_BUSN_LAST(busn); > + > + /* All RCiEP devices are on the same bus as the RCEC */ > + if (nextbusn == 0xff && lastbusn == 0x00) > + return; > + > + for (bnr = nextbusn; bnr < (lastbusn + 1); bnr++) { Why not bnr <= lastbusn? Seems more intuitive way of making it clear the range is inclusive. > + pbus = pci_find_bus(pci_domain_nr(rcec->bus), bnr); > + if (!pbus) > + continue; > + > + /* Find RCiEP devices on the given bus */ > + if (pcie_walk_rciep_devfn(pbus, cb, userdata, 0xffffffff)) > + return; > + } > +} > + > #ifdef CONFIG_PM > typedef int (*pcie_pm_callback_t)(struct pcie_device *); >