From patchwork Mon Jan 23 12:17:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 13112011 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 A370AC38142 for ; Mon, 23 Jan 2023 12:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231512AbjAWMRt (ORCPT ); Mon, 23 Jan 2023 07:17:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231621AbjAWMRr (ORCPT ); Mon, 23 Jan 2023 07:17:47 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADDC8FF for ; Mon, 23 Jan 2023 04:17:44 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4P0ptt0RDLz6J68f; Mon, 23 Jan 2023 20:14:30 +0800 (CST) Received: from SecurePC-101-06.china.huawei.com (10.122.247.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 23 Jan 2023 12:17:42 +0000 From: Jonathan Cameron To: CC: Ben Widawsky , , , Ira Weiny , Dave Jiang , , Fan Ni Subject: [RFC PATCH 1/2] hw/pci: Add pcie_count_ds_port() and pcie_find_port_first() helpers Date: Mon, 23 Jan 2023 12:17:11 +0000 Message-ID: <20230123121712.29892-2-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> References: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org These two helpers enable host bridges to operate differently depending on the number of downstream ports, in particular if there is only a single port. Useful for CXL where HDM address decoders are allowed to be implicit in the host bridge if there is only a single root port. Signed-off-by: Jonathan Cameron --- hw/pci/pcie_port.c | 38 ++++++++++++++++++++++++++++++++++++++ include/hw/pci/pcie_port.h | 2 ++ 2 files changed, 40 insertions(+) diff --git a/hw/pci/pcie_port.c b/hw/pci/pcie_port.c index 687e4e763a..b709777e0c 100644 --- a/hw/pci/pcie_port.c +++ b/hw/pci/pcie_port.c @@ -161,6 +161,44 @@ PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn) return NULL; } +/* Find first port in devfn number */ +PCIDevice *pcie_find_port_first(PCIBus *bus) +{ + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + return d; + } + } + + return NULL; +} + +int pcie_count_ds_ports(PCIBus *bus) +{ + int dsp_count = 0; + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + dsp_count++; + } + } + return dsp_count; +} + static const TypeInfo pcie_port_type_info = { .name = TYPE_PCIE_PORT, .parent = TYPE_PCI_BRIDGE, diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h index fd484afb30..2cbad72555 100644 --- a/include/hw/pci/pcie_port.h +++ b/include/hw/pci/pcie_port.h @@ -41,6 +41,8 @@ struct PCIEPort { void pcie_port_init_reg(PCIDevice *d); PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn); +PCIDevice *pcie_find_port_first(PCIBus *bus); +int pcie_count_ds_ports(PCIBus *bus); #define TYPE_PCIE_SLOT "pcie-slot" OBJECT_DECLARE_SIMPLE_TYPE(PCIESlot, PCIE_SLOT)