From patchwork Wed Jan 26 18:55:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12725626 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D3CD2CA3 for ; Wed, 26 Jan 2022 18:57:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643223474; x=1674759474; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=O4XFS+cMxB3guXfYh3xOPZvyNe5ZhUz0man7dHUKeis=; b=Wg1jl3uykhE6SHKnEkDFQyN5pusH6XuhvrnQVbejWUIZjlAZ73mgl14Y WYIYRjgVuzx9Femhaf3F0pFx0E7+mpNNpRWJ1tZwvVYT3xjIoR7bfljUi sdDvT/NZ+WUhhl8aa0g7SD+7jN4XujBviVAc5BVkZHu+GkocpXtwDaNXO L1rgP3EPhBabzoS7K+6/N/9h03fpJUAP5ACRLyyAfbUFpz2vhy8yo4Zck m3i84ofts2UJpMa4lBfLqUInC+7f2o5mk2IMPyfIiiQd7Pqo7BkiOPth2 Dp7Vz7/QAb54EgZcrcQjWcqEqvThW57XjkIGFxXHrUVGzNWnyt+DCglQT g==; X-IronPort-AV: E=McAfee;i="6200,9189,10238"; a="245459092" X-IronPort-AV: E=Sophos;i="5.88,318,1635231600"; d="scan'208";a="245459092" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 10:55:40 -0800 X-IronPort-AV: E=Sophos;i="5.88,318,1635231600"; d="scan'208";a="628398474" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 10:55:39 -0800 Subject: [PATCH v4 18/40] cxl/pmem: Introduce a find_cxl_root() helper From: Dan Williams To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-pci@vger.kernel.org, nvdimm@lists.linux.dev Date: Wed, 26 Jan 2022 10:55:39 -0800 Message-ID: <164322333437.3694981.17087130505938650994.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <164298421461.3018233.9903386694598524146.stgit@dwillia2-desk3.amr.corp.intel.com> References: <164298421461.3018233.9903386694598524146.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In preparation for switch port enumeration while also preserving the potential for multi-domain / multi-root CXL topologies. Introduce a 'struct device' generic mechanism for retrieving a root CXL port, if one is registered. Note that the only know multi-domain CXL configurations are running the cxl_test unit test on a system that also publishes an ACPI0017 device. With this in hand the nvdimm-bridge lookup can be with device_find_child() instead of bus_find_device() + custom mocked lookup infrastructure in cxl_test. The mechanism looks for a 2nd level port since the root level topology is platform-firmware specific and the 2nd level down follows standard PCIe topology expectations. The cxl_acpi 2nd level is associated with a PCIe Root Port. Reported-by: Ben Widawsky Signed-off-by: Dan Williams --- Changes since v4 - Fix root lookup in the presence of ACPI Host Bridge topology. Previous version was only tested with cxl_test. (Ben) drivers/cxl/core/pmem.c | 14 +++++++++--- drivers/cxl/core/port.c | 48 +++++++++++++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 1 + tools/testing/cxl/Kbuild | 2 -- tools/testing/cxl/mock_pmem.c | 24 --------------------- 5 files changed, 59 insertions(+), 30 deletions(-) delete mode 100644 tools/testing/cxl/mock_pmem.c diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index 40b3f5030496..8de240c4d96b 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -57,24 +57,30 @@ bool is_cxl_nvdimm_bridge(struct device *dev) } EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, CXL); -__mock int match_nvdimm_bridge(struct device *dev, const void *data) +static int match_nvdimm_bridge(struct device *dev, void *data) { return is_cxl_nvdimm_bridge(dev); } struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_nvdimm *cxl_nvd) { + struct cxl_port *port = find_cxl_root(&cxl_nvd->dev); struct device *dev; - dev = bus_find_device(&cxl_bus_type, NULL, cxl_nvd, match_nvdimm_bridge); + if (!port) + return NULL; + + dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge); + put_device(&port->dev); + if (!dev) return NULL; + return to_cxl_nvdimm_bridge(dev); } EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL); -static struct cxl_nvdimm_bridge * -cxl_nvdimm_bridge_alloc(struct cxl_port *port) +static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port) { struct cxl_nvdimm_bridge *cxl_nvb; struct device *dev; diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 4c921c49f967..89f445b04b7b 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -457,6 +457,54 @@ int devm_cxl_register_pci_bus(struct device *host, struct device *uport, } EXPORT_SYMBOL_NS_GPL(devm_cxl_register_pci_bus, CXL); +/* Find a 2nd level CXL port that has a dport that is an ancestor of @match */ +static int match_cxl_root_child(struct device *dev, const void *match) +{ + const struct device *iter = match; + struct cxl_port *port, *parent; + struct cxl_dport *dport; + + if (!is_cxl_port(dev)) + return 0; + + port = to_cxl_port(dev); + if (is_cxl_root(port)) + return 0; + + parent = to_cxl_port(port->dev.parent); + if (!is_cxl_root(parent)) + return 0; + + cxl_device_lock(&port->dev); + list_for_each_entry(dport, &port->dports, list) + while (iter) { + if (iter == dport->dport) + goto out; + iter = iter->parent; + } +out: + cxl_device_unlock(&port->dev); + + return !!iter; +} + +struct cxl_port *find_cxl_root(struct device *dev) +{ + struct device *port_dev; + struct cxl_port *root; + + port_dev = + bus_find_device(&cxl_bus_type, NULL, dev, match_cxl_root_child); + if (!port_dev) + return NULL; + + root = to_cxl_port(port_dev->parent); + get_device(&root->dev); + put_device(port_dev); + return root; +} +EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL); + static struct cxl_dport *find_dport(struct cxl_port *port, int id) { struct cxl_dport *dport; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 4e8d504546c5..7523e4d60953 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -298,6 +298,7 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, resource_size_t component_reg_phys); +struct cxl_port *find_cxl_root(struct device *dev); struct cxl_decoder *to_cxl_decoder(struct device *dev); bool is_root_decoder(struct device *dev); diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild index 3299fb0977b2..ddaee8a2c418 100644 --- a/tools/testing/cxl/Kbuild +++ b/tools/testing/cxl/Kbuild @@ -32,6 +32,4 @@ cxl_core-y += $(CXL_CORE_SRC)/memdev.o cxl_core-y += $(CXL_CORE_SRC)/mbox.o cxl_core-y += config_check.o -cxl_core-y += mock_pmem.o - obj-m += test/ diff --git a/tools/testing/cxl/mock_pmem.c b/tools/testing/cxl/mock_pmem.c deleted file mode 100644 index f7315e6f52c0..000000000000 --- a/tools/testing/cxl/mock_pmem.c +++ /dev/null @@ -1,24 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ -#include -#include "test/mock.h" -#include - -int match_nvdimm_bridge(struct device *dev, const void *data) -{ - int index, rc = 0; - struct cxl_mock_ops *ops = get_cxl_mock_ops(&index); - const struct cxl_nvdimm *cxl_nvd = data; - - if (ops) { - if (dev->type == &cxl_nvdimm_bridge_type && - (ops->is_mock_dev(dev->parent->parent) == - ops->is_mock_dev(cxl_nvd->dev.parent->parent))) - rc = 1; - } else - rc = dev->type == &cxl_nvdimm_bridge_type; - - put_cxl_mock_ops(index); - - return rc; -}