From patchwork Thu Jun 10 22:26:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12314189 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) (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 894102F80 for ; Thu, 10 Jun 2021 22:26:04 +0000 (UTC) IronPort-SDR: t7JRLW4PeQMfs4WtJFa7xhMwrJCKFjXeD/ds3IkxqK6LJe3eKvJPJgrg49gO1OhYy/j5bH1k4w Td187wTctZsA== X-IronPort-AV: E=McAfee;i="6200,9189,10011"; a="202389738" X-IronPort-AV: E=Sophos;i="5.83,264,1616482800"; d="scan'208";a="202389738" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2021 15:26:03 -0700 IronPort-SDR: eMi06YvR8fFJbXi4k30yNOdMW7Pe4K3RAq4Y3Jv9/ANyw+rSC21yUVWWvJdn88XlQieP7tWjnn v6UtM1wrERBw== X-IronPort-AV: E=Sophos;i="5.83,264,1616482800"; d="scan'208";a="552508664" 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; 10 Jun 2021 15:26:03 -0700 Subject: [PATCH 1/5] cxl/core: Add cxl-bus driver infrastructure From: Dan Williams To: linux-cxl@vger.kernel.org Cc: nvdimm@lists.linux.dev, ben.widawsky@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, linux-kernel@vger.kernel.org Date: Thu, 10 Jun 2021 15:26:03 -0700 Message-ID: <162336396329.2462439.16556923116284874437.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <162336395765.2462439.11368504490069925374.stgit@dwillia2-desk3.amr.corp.intel.com> References: <162336395765.2462439.11368504490069925374.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Enable devices on the 'cxl' bus to be attached to drivers. The initial user of this functionality is a driver for an 'nvdimm-bridge' device that anchors a libnvdimm hierarchy attached to CXL persistent memory resources. Other device types that will leverage this include: cxl_port: map and use component register functionality (HDM Decoders) cxl_nvdimm: translate CXL memory expander endpoints to libnvdimm 'nvdimm' objects cxl_region: translate CXL interleave sets to libnvdimm 'region' objects The pairing of devices to drivers is handled through the cxl_device_id() matching to cxl_driver.id values. A cxl_device_id() of '0' indicates no driver support. In addition to ->match(), ->probe(), and ->remove() support for the 'cxl' bus introduce MODULE_ALIAS_CXL() to autoload modules containing cxl-drivers. Drivers are added in follow-on changes. Signed-off-by: Dan Williams --- drivers/cxl/core.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 22 ++++++++++++++++ 2 files changed, 95 insertions(+) diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index 1b9ee0b08384..959cecc1f6bf 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -767,8 +767,81 @@ int cxl_map_device_regs(struct pci_dev *pdev, } EXPORT_SYMBOL_GPL(cxl_map_device_regs); +/** + * __cxl_driver_register - register a driver for the cxl bus + * @cxl_drv: cxl driver structure to attach + * @owner: owning module/driver + * @modname: KBUILD_MODNAME for parent driver + */ +int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, + const char *modname) +{ + if (!cxl_drv->probe) { + pr_debug("%s ->probe() must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->name) { + pr_debug("%s ->name must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->id) { + pr_debug("%s ->id must be specified\n", modname); + return -EINVAL; + } + + cxl_drv->drv.bus = &cxl_bus_type; + cxl_drv->drv.owner = owner; + cxl_drv->drv.mod_name = modname; + cxl_drv->drv.name = cxl_drv->name; + + return driver_register(&cxl_drv->drv); +} +EXPORT_SYMBOL_GPL(__cxl_driver_register); + +void cxl_driver_unregister(struct cxl_driver *cxl_drv) +{ + driver_unregister(&cxl_drv->drv); +} +EXPORT_SYMBOL_GPL(cxl_driver_unregister); + +static int cxl_device_id(struct device *dev) +{ + return 0; +} + +static int cxl_bus_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + return add_uevent_var(env, "MODALIAS=" CXL_MODALIAS_FMT, + cxl_device_id(dev)); +} + +static int cxl_bus_match(struct device *dev, struct device_driver *drv) +{ + return cxl_device_id(dev) == to_cxl_drv(drv)->id; +} + +static int cxl_bus_probe(struct device *dev) +{ + return to_cxl_drv(dev->driver)->probe(dev); +} + +static int cxl_bus_remove(struct device *dev) +{ + struct cxl_driver *cxl_drv = to_cxl_drv(dev->driver); + + if (cxl_drv->remove) + cxl_drv->remove(dev); + return 0; +} + struct bus_type cxl_bus_type = { .name = "cxl", + .uevent = cxl_bus_uevent, + .match = cxl_bus_match, + .probe = cxl_bus_probe, + .remove = cxl_bus_remove, }; EXPORT_SYMBOL_GPL(cxl_bus_type); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index b988ea288f53..af2237d1c761 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -261,4 +261,26 @@ devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port) } extern struct bus_type cxl_bus_type; + +struct cxl_driver { + const char *name; + int (*probe)(struct device *dev); + void (*remove)(struct device *dev); + struct device_driver drv; + int id; +}; + +static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv) +{ + return container_of(drv, struct cxl_driver, drv); +} + +int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, + const char *modname); +#define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME) +void cxl_driver_unregister(struct cxl_driver *cxl_drv); + +#define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") +#define CXL_MODALIAS_FMT "cxl:t%d" + #endif /* __CXL_H__ */