// SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2022 Intel Corporation. All rights reserved. */ #include #include #include #include #include "cxlmem.h" #include "cxlpci.h" /** * DOC: cxl mem * * CXL memory endpoint devices and switches are CXL capable devices that are * participating in CXL.mem protocol. Their functionality builds on top of the * CXL.io protocol that allows enumerating and configuring components via * standard PCI mechanisms. * * The cxl_mem driver owns kicking off the enumeration of this CXL.mem * capability. With the detection of a CXL capable endpoint, the driver will * walk up to find the platform specific port it is connected to, and determine * if there are intervening switches in the path. If there are switches, a * secondary action is to enumerate those (implemented in cxl_core). Finally the * cxl_mem driver adds the device it is bound to as a CXL endpoint-port for use * in higher level operations. */ static void enable_suspend(void *data) { cxl_mem_active_dec(); } static void remove_debugfs(void *dentry) { debugfs_remove_recursive(dentry); } static int cxl_mem_dpa_show(struct seq_file *file, void *data) { struct device *dev = file->private; struct cxl_memdev *cxlmd = to_cxl_memdev(dev); cxl_dpa_debug(file, cxlmd->cxlds); return 0; } static int cxl_debugfs_poison_inject(void *data, u64 dpa) { struct cxl_memdev *cxlmd = data; return cxl_inject_poison(cxlmd, dpa); } DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_inject_fops, NULL, cxl_debugfs_poison_inject, "%llx\n"); static int cxl_debugfs_poison_clear(void *data, u64 dpa) { struct cxl_memdev *cxlmd = data; return cxl_clear_poison(cxlmd, dpa); } DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_clear_fops, NULL, cxl_debugfs_poison_clear, "%llx\n"); static int cxl_mem_probe(struct device *dev) { struct cxl_memdev *cxlmd = to_cxl_memdev(dev); struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); struct cxl_dev_state *cxlds = cxlmd->cxlds; struct device *endpoint_parent; struct cxl_dport *dport; struct dentry *dentry; int rc; if (!cxlds->media_ready) return -EBUSY; /* * Someone is trying to reattach this device after it lost its port * connection (an endpoint port previously registered by this memdev was * disabled). This racy check is ok because if the port is still gone, * no harm done, and if the port hierarchy comes back it will re-trigger * this probe. Port rescan and memdev detach work share the same * single-threaded workqueue. */ if (work_pending(&cxlmd->detach_work)) return -EBUSY; dentry = cxl_debugfs_create_dir(dev_name(dev)); debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show); if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds)) debugfs_create_file("inject_poison", 0200, dentry, cxlmd, &cxl_poison_inject_fops); if (test_bit(CXL_POISON_ENABLED_CLEAR, mds->poison.enabled_cmds)) debugfs_create_file("clear_poison", 0200, dentry, cxlmd, &cxl_poison_clear_fops); rc = devm_add_action_or_reset(dev, remove_debugfs, dentry); if (rc) return rc; rc = devm_cxl_enumerate_ports(cxlmd); if (rc) return rc; struct cxl_port *parent_port __free(put_cxl_port) = cxl_mem_find_port(cxlmd, &dport); if (!parent_port) { dev_err(dev, "CXL port topology not found\n"); return -ENXIO; } if (cxl_pmem_size(cxlds) && IS_ENABLED(CONFIG_CXL_PMEM)) { rc = devm_cxl_add_nvdimm(dev, parent_port, cxlmd); if (rc) { if (rc == -ENODEV) dev_info(dev, "PMEM disabled by platform\n"); return rc; } } if (dport->rch) endpoint_parent = parent_port->uport_dev; else endpoint_parent = &parent_port->dev; scoped_guard(device, endpoint_parent) { if (!endpoint_parent->driver) { dev_err(dev, "CXL port topology %s not enabled\n", dev_name(endpoint_parent)); return -ENXIO; } rc = devm_cxl_add_endpoint(endpoint_parent, cxlmd, dport); if (rc) return rc; } if (cxlmd->attach) { rc = cxlmd->attach->probe(cxlmd); if (rc) return rc; } rc = devm_cxl_memdev_edac_register(cxlmd); if (rc) dev_dbg(dev, "CXL memdev EDAC registration failed rc=%d\n", rc); /* * The kernel may be operating out of CXL memory on this device, * there is no spec defined way to determine whether this device * preserves contents over suspend, and there is no simple way * to arrange for the suspend image to avoid CXL memory which * would setup a circular dependency between PCI resume and save * state restoration. * * TODO: support suspend when all the regions this device is * hosting are locked and covered by the system address map, * i.e. platform firmware owns restoring the HDM configuration * that it locked. */ cxl_mem_active_inc(); return devm_add_action_or_reset(dev, enable_suspend, NULL); } /** * devm_cxl_add_memdev - Add a CXL memory device * @cxlds: CXL device state to associate with the memdev * @attach: Caller depends on CXL topology attachment * * Upon return the device will have had a chance to attach to the * cxl_mem driver, but may fail to attach if the CXL topology is not ready * (hardware CXL link down, or software platform CXL root not attached). * * When @attach is NULL it indicates the caller wants the memdev to remain * registered even if it does not immediately attach to the CXL hierarchy. When * @attach is provided a cxl_mem_probe() failure leads to failure of this routine. * * The parent of the resulting device and the devm context for allocations is * @cxlds->dev. */ struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds, const struct cxl_memdev_attach *attach) { return __devm_cxl_add_memdev(cxlds, attach); } EXPORT_SYMBOL_NS_GPL(devm_cxl_add_memdev, "CXL"); static ssize_t trigger_poison_list_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { bool trigger; int rc; if (kstrtobool(buf, &trigger) || !trigger) return -EINVAL; rc = cxl_trigger_poison_list(to_cxl_memdev(dev)); return rc ? rc : len; } static DEVICE_ATTR_WO(trigger_poison_list); static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = kobj_to_dev(kobj); struct cxl_memdev *cxlmd = to_cxl_memdev(dev); struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); if (a == &dev_attr_trigger_poison_list.attr) if (!test_bit(CXL_POISON_ENABLED_LIST, mds->poison.enabled_cmds)) return 0; return a->mode; } static struct attribute *cxl_mem_attrs[] = { &dev_attr_trigger_poison_list.attr, NULL }; static struct attribute_group cxl_mem_group = { .attrs = cxl_mem_attrs, .is_visible = cxl_mem_visible, }; __ATTRIBUTE_GROUPS(cxl_mem); static struct cxl_driver cxl_mem_driver = { .name = "cxl_mem", .probe = cxl_mem_probe, .id = CXL_DEVICE_MEMORY_EXPANDER, .drv = { .probe_type = PROBE_FORCE_SYNCHRONOUS, .dev_groups = cxl_mem_groups, }, }; module_cxl_driver(cxl_mem_driver); MODULE_DESCRIPTION("CXL: Memory Expansion"); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS("CXL"); MODULE_ALIAS_CXL(CXL_DEVICE_MEMORY_EXPANDER);