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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright(c) 2020 Intel Corporation. All rights reserved. */3#include <linux/platform_device.h>4#include <linux/memregion.h>5#include <linux/workqueue.h>6#include <linux/debugfs.h>7#include <linux/device.h>8#include <linux/module.h>9#include <linux/pci.h>10#include <linux/slab.h>11#include <linux/idr.h>12#include <linux/node.h>13#include <cxl/einj.h>14#include <cxlmem.h>15#include <cxlpci.h>16#include <cxl.h>17#include "core.h"18 19/**20 * DOC: cxl core21 *22 * The CXL core provides a set of interfaces that can be consumed by CXL aware23 * drivers. The interfaces allow for creation, modification, and destruction of24 * regions, memory devices, ports, and decoders. CXL aware drivers must register25 * with the CXL core via these interfaces in order to be able to participate in26 * cross-device interleave coordination. The CXL core also establishes and27 * maintains the bridge to the nvdimm subsystem.28 *29 * CXL core introduces sysfs hierarchy to control the devices that are30 * instantiated by the core.31 */32 33/*34 * All changes to the interleave configuration occur with this lock held35 * for write.36 */37DECLARE_RWSEM(cxl_region_rwsem);38 39static DEFINE_IDA(cxl_port_ida);40static DEFINE_XARRAY(cxl_root_buses);41 42int cxl_num_decoders_committed(struct cxl_port *port)43{44	lockdep_assert_held(&cxl_region_rwsem);45 46	return port->commit_end + 1;47}48 49static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,50			    char *buf)51{52	return sysfs_emit(buf, "%s\n", dev->type->name);53}54static DEVICE_ATTR_RO(devtype);55 56static int cxl_device_id(const struct device *dev)57{58	if (dev->type == &cxl_nvdimm_bridge_type)59		return CXL_DEVICE_NVDIMM_BRIDGE;60	if (dev->type == &cxl_nvdimm_type)61		return CXL_DEVICE_NVDIMM;62	if (dev->type == CXL_PMEM_REGION_TYPE())63		return CXL_DEVICE_PMEM_REGION;64	if (dev->type == CXL_DAX_REGION_TYPE())65		return CXL_DEVICE_DAX_REGION;66	if (is_cxl_port(dev)) {67		if (is_cxl_root(to_cxl_port(dev)))68			return CXL_DEVICE_ROOT;69		return CXL_DEVICE_PORT;70	}71	if (is_cxl_memdev(dev))72		return CXL_DEVICE_MEMORY_EXPANDER;73	if (dev->type == CXL_REGION_TYPE())74		return CXL_DEVICE_REGION;75	if (dev->type == &cxl_pmu_type)76		return CXL_DEVICE_PMU;77	return 0;78}79 80static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,81			     char *buf)82{83	return sysfs_emit(buf, CXL_MODALIAS_FMT "\n", cxl_device_id(dev));84}85static DEVICE_ATTR_RO(modalias);86 87static struct attribute *cxl_base_attributes[] = {88	&dev_attr_devtype.attr,89	&dev_attr_modalias.attr,90	NULL,91};92 93struct attribute_group cxl_base_attribute_group = {94	.attrs = cxl_base_attributes,95};96 97static ssize_t start_show(struct device *dev, struct device_attribute *attr,98			  char *buf)99{100	struct cxl_decoder *cxld = to_cxl_decoder(dev);101 102	return sysfs_emit(buf, "%#llx\n", cxld->hpa_range.start);103}104static DEVICE_ATTR_ADMIN_RO(start);105 106static ssize_t size_show(struct device *dev, struct device_attribute *attr,107			char *buf)108{109	struct cxl_decoder *cxld = to_cxl_decoder(dev);110 111	return sysfs_emit(buf, "%#llx\n", range_len(&cxld->hpa_range));112}113static DEVICE_ATTR_RO(size);114 115#define CXL_DECODER_FLAG_ATTR(name, flag)                            \116static ssize_t name##_show(struct device *dev,                       \117			   struct device_attribute *attr, char *buf) \118{                                                                    \119	struct cxl_decoder *cxld = to_cxl_decoder(dev);              \120                                                                     \121	return sysfs_emit(buf, "%s\n",                               \122			  (cxld->flags & (flag)) ? "1" : "0");       \123}                                                                    \124static DEVICE_ATTR_RO(name)125 126CXL_DECODER_FLAG_ATTR(cap_pmem, CXL_DECODER_F_PMEM);127CXL_DECODER_FLAG_ATTR(cap_ram, CXL_DECODER_F_RAM);128CXL_DECODER_FLAG_ATTR(cap_type2, CXL_DECODER_F_TYPE2);129CXL_DECODER_FLAG_ATTR(cap_type3, CXL_DECODER_F_TYPE3);130CXL_DECODER_FLAG_ATTR(locked, CXL_DECODER_F_LOCK);131 132static ssize_t target_type_show(struct device *dev,133				struct device_attribute *attr, char *buf)134{135	struct cxl_decoder *cxld = to_cxl_decoder(dev);136 137	switch (cxld->target_type) {138	case CXL_DECODER_DEVMEM:139		return sysfs_emit(buf, "accelerator\n");140	case CXL_DECODER_HOSTONLYMEM:141		return sysfs_emit(buf, "expander\n");142	}143	return -ENXIO;144}145static DEVICE_ATTR_RO(target_type);146 147static ssize_t emit_target_list(struct cxl_switch_decoder *cxlsd, char *buf)148{149	struct cxl_decoder *cxld = &cxlsd->cxld;150	ssize_t offset = 0;151	int i, rc = 0;152 153	for (i = 0; i < cxld->interleave_ways; i++) {154		struct cxl_dport *dport = cxlsd->target[i];155		struct cxl_dport *next = NULL;156 157		if (!dport)158			break;159 160		if (i + 1 < cxld->interleave_ways)161			next = cxlsd->target[i + 1];162		rc = sysfs_emit_at(buf, offset, "%d%s", dport->port_id,163				   next ? "," : "");164		if (rc < 0)165			return rc;166		offset += rc;167	}168 169	return offset;170}171 172static ssize_t target_list_show(struct device *dev,173				struct device_attribute *attr, char *buf)174{175	struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);176	ssize_t offset;177	int rc;178 179	guard(rwsem_read)(&cxl_region_rwsem);180	rc = emit_target_list(cxlsd, buf);181	if (rc < 0)182		return rc;183	offset = rc;184 185	rc = sysfs_emit_at(buf, offset, "\n");186	if (rc < 0)187		return rc;188 189	return offset + rc;190}191static DEVICE_ATTR_RO(target_list);192 193static ssize_t mode_show(struct device *dev, struct device_attribute *attr,194			 char *buf)195{196	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);197 198	return sysfs_emit(buf, "%s\n", cxl_decoder_mode_name(cxled->mode));199}200 201static ssize_t mode_store(struct device *dev, struct device_attribute *attr,202			  const char *buf, size_t len)203{204	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);205	enum cxl_decoder_mode mode;206	ssize_t rc;207 208	if (sysfs_streq(buf, "pmem"))209		mode = CXL_DECODER_PMEM;210	else if (sysfs_streq(buf, "ram"))211		mode = CXL_DECODER_RAM;212	else213		return -EINVAL;214 215	rc = cxl_dpa_set_mode(cxled, mode);216	if (rc)217		return rc;218 219	return len;220}221static DEVICE_ATTR_RW(mode);222 223static ssize_t dpa_resource_show(struct device *dev, struct device_attribute *attr,224			    char *buf)225{226	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);227 228	guard(rwsem_read)(&cxl_dpa_rwsem);229	return sysfs_emit(buf, "%#llx\n", (u64)cxl_dpa_resource_start(cxled));230}231static DEVICE_ATTR_RO(dpa_resource);232 233static ssize_t dpa_size_show(struct device *dev, struct device_attribute *attr,234			     char *buf)235{236	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);237	resource_size_t size = cxl_dpa_size(cxled);238 239	return sysfs_emit(buf, "%pa\n", &size);240}241 242static ssize_t dpa_size_store(struct device *dev, struct device_attribute *attr,243			      const char *buf, size_t len)244{245	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);246	unsigned long long size;247	ssize_t rc;248 249	rc = kstrtoull(buf, 0, &size);250	if (rc)251		return rc;252 253	if (!IS_ALIGNED(size, SZ_256M))254		return -EINVAL;255 256	rc = cxl_dpa_free(cxled);257	if (rc)258		return rc;259 260	if (size == 0)261		return len;262 263	rc = cxl_dpa_alloc(cxled, size);264	if (rc)265		return rc;266 267	return len;268}269static DEVICE_ATTR_RW(dpa_size);270 271static ssize_t interleave_granularity_show(struct device *dev,272					   struct device_attribute *attr,273					   char *buf)274{275	struct cxl_decoder *cxld = to_cxl_decoder(dev);276 277	return sysfs_emit(buf, "%d\n", cxld->interleave_granularity);278}279 280static DEVICE_ATTR_RO(interleave_granularity);281 282static ssize_t interleave_ways_show(struct device *dev,283				    struct device_attribute *attr, char *buf)284{285	struct cxl_decoder *cxld = to_cxl_decoder(dev);286 287	return sysfs_emit(buf, "%d\n", cxld->interleave_ways);288}289 290static DEVICE_ATTR_RO(interleave_ways);291 292static ssize_t qos_class_show(struct device *dev,293			      struct device_attribute *attr, char *buf)294{295	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);296 297	return sysfs_emit(buf, "%d\n", cxlrd->qos_class);298}299static DEVICE_ATTR_RO(qos_class);300 301static struct attribute *cxl_decoder_base_attrs[] = {302	&dev_attr_start.attr,303	&dev_attr_size.attr,304	&dev_attr_locked.attr,305	&dev_attr_interleave_granularity.attr,306	&dev_attr_interleave_ways.attr,307	NULL,308};309 310static struct attribute_group cxl_decoder_base_attribute_group = {311	.attrs = cxl_decoder_base_attrs,312};313 314static struct attribute *cxl_decoder_root_attrs[] = {315	&dev_attr_cap_pmem.attr,316	&dev_attr_cap_ram.attr,317	&dev_attr_cap_type2.attr,318	&dev_attr_cap_type3.attr,319	&dev_attr_target_list.attr,320	&dev_attr_qos_class.attr,321	SET_CXL_REGION_ATTR(create_pmem_region)322	SET_CXL_REGION_ATTR(create_ram_region)323	SET_CXL_REGION_ATTR(delete_region)324	NULL,325};326 327static bool can_create_pmem(struct cxl_root_decoder *cxlrd)328{329	unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_PMEM;330 331	return (cxlrd->cxlsd.cxld.flags & flags) == flags;332}333 334static bool can_create_ram(struct cxl_root_decoder *cxlrd)335{336	unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_RAM;337 338	return (cxlrd->cxlsd.cxld.flags & flags) == flags;339}340 341static umode_t cxl_root_decoder_visible(struct kobject *kobj, struct attribute *a, int n)342{343	struct device *dev = kobj_to_dev(kobj);344	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);345 346	if (a == CXL_REGION_ATTR(create_pmem_region) && !can_create_pmem(cxlrd))347		return 0;348 349	if (a == CXL_REGION_ATTR(create_ram_region) && !can_create_ram(cxlrd))350		return 0;351 352	if (a == CXL_REGION_ATTR(delete_region) &&353	    !(can_create_pmem(cxlrd) || can_create_ram(cxlrd)))354		return 0;355 356	return a->mode;357}358 359static struct attribute_group cxl_decoder_root_attribute_group = {360	.attrs = cxl_decoder_root_attrs,361	.is_visible = cxl_root_decoder_visible,362};363 364static const struct attribute_group *cxl_decoder_root_attribute_groups[] = {365	&cxl_decoder_root_attribute_group,366	&cxl_decoder_base_attribute_group,367	&cxl_base_attribute_group,368	NULL,369};370 371static struct attribute *cxl_decoder_switch_attrs[] = {372	&dev_attr_target_type.attr,373	&dev_attr_target_list.attr,374	SET_CXL_REGION_ATTR(region)375	NULL,376};377 378static struct attribute_group cxl_decoder_switch_attribute_group = {379	.attrs = cxl_decoder_switch_attrs,380};381 382static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = {383	&cxl_decoder_switch_attribute_group,384	&cxl_decoder_base_attribute_group,385	&cxl_base_attribute_group,386	NULL,387};388 389static struct attribute *cxl_decoder_endpoint_attrs[] = {390	&dev_attr_target_type.attr,391	&dev_attr_mode.attr,392	&dev_attr_dpa_size.attr,393	&dev_attr_dpa_resource.attr,394	SET_CXL_REGION_ATTR(region)395	NULL,396};397 398static struct attribute_group cxl_decoder_endpoint_attribute_group = {399	.attrs = cxl_decoder_endpoint_attrs,400};401 402static const struct attribute_group *cxl_decoder_endpoint_attribute_groups[] = {403	&cxl_decoder_base_attribute_group,404	&cxl_decoder_endpoint_attribute_group,405	&cxl_base_attribute_group,406	NULL,407};408 409static void __cxl_decoder_release(struct cxl_decoder *cxld)410{411	struct cxl_port *port = to_cxl_port(cxld->dev.parent);412 413	ida_free(&port->decoder_ida, cxld->id);414	put_device(&port->dev);415}416 417static void cxl_endpoint_decoder_release(struct device *dev)418{419	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);420 421	__cxl_decoder_release(&cxled->cxld);422	kfree(cxled);423}424 425static void cxl_switch_decoder_release(struct device *dev)426{427	struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);428 429	__cxl_decoder_release(&cxlsd->cxld);430	kfree(cxlsd);431}432 433struct cxl_root_decoder *to_cxl_root_decoder(struct device *dev)434{435	if (dev_WARN_ONCE(dev, !is_root_decoder(dev),436			  "not a cxl_root_decoder device\n"))437		return NULL;438	return container_of(dev, struct cxl_root_decoder, cxlsd.cxld.dev);439}440EXPORT_SYMBOL_NS_GPL(to_cxl_root_decoder, CXL);441 442static void cxl_root_decoder_release(struct device *dev)443{444	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);445 446	if (atomic_read(&cxlrd->region_id) >= 0)447		memregion_free(atomic_read(&cxlrd->region_id));448	__cxl_decoder_release(&cxlrd->cxlsd.cxld);449	kfree(cxlrd);450}451 452static const struct device_type cxl_decoder_endpoint_type = {453	.name = "cxl_decoder_endpoint",454	.release = cxl_endpoint_decoder_release,455	.groups = cxl_decoder_endpoint_attribute_groups,456};457 458static const struct device_type cxl_decoder_switch_type = {459	.name = "cxl_decoder_switch",460	.release = cxl_switch_decoder_release,461	.groups = cxl_decoder_switch_attribute_groups,462};463 464static const struct device_type cxl_decoder_root_type = {465	.name = "cxl_decoder_root",466	.release = cxl_root_decoder_release,467	.groups = cxl_decoder_root_attribute_groups,468};469 470bool is_endpoint_decoder(struct device *dev)471{472	return dev->type == &cxl_decoder_endpoint_type;473}474EXPORT_SYMBOL_NS_GPL(is_endpoint_decoder, CXL);475 476bool is_root_decoder(struct device *dev)477{478	return dev->type == &cxl_decoder_root_type;479}480EXPORT_SYMBOL_NS_GPL(is_root_decoder, CXL);481 482bool is_switch_decoder(struct device *dev)483{484	return is_root_decoder(dev) || dev->type == &cxl_decoder_switch_type;485}486EXPORT_SYMBOL_NS_GPL(is_switch_decoder, CXL);487 488struct cxl_decoder *to_cxl_decoder(struct device *dev)489{490	if (dev_WARN_ONCE(dev,491			  !is_switch_decoder(dev) && !is_endpoint_decoder(dev),492			  "not a cxl_decoder device\n"))493		return NULL;494	return container_of(dev, struct cxl_decoder, dev);495}496EXPORT_SYMBOL_NS_GPL(to_cxl_decoder, CXL);497 498struct cxl_endpoint_decoder *to_cxl_endpoint_decoder(struct device *dev)499{500	if (dev_WARN_ONCE(dev, !is_endpoint_decoder(dev),501			  "not a cxl_endpoint_decoder device\n"))502		return NULL;503	return container_of(dev, struct cxl_endpoint_decoder, cxld.dev);504}505EXPORT_SYMBOL_NS_GPL(to_cxl_endpoint_decoder, CXL);506 507struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev)508{509	if (dev_WARN_ONCE(dev, !is_switch_decoder(dev),510			  "not a cxl_switch_decoder device\n"))511		return NULL;512	return container_of(dev, struct cxl_switch_decoder, cxld.dev);513}514EXPORT_SYMBOL_NS_GPL(to_cxl_switch_decoder, CXL);515 516static void cxl_ep_release(struct cxl_ep *ep)517{518	put_device(ep->ep);519	kfree(ep);520}521 522static void cxl_ep_remove(struct cxl_port *port, struct cxl_ep *ep)523{524	if (!ep)525		return;526	xa_erase(&port->endpoints, (unsigned long) ep->ep);527	cxl_ep_release(ep);528}529 530static void cxl_port_release(struct device *dev)531{532	struct cxl_port *port = to_cxl_port(dev);533	unsigned long index;534	struct cxl_ep *ep;535 536	xa_for_each(&port->endpoints, index, ep)537		cxl_ep_remove(port, ep);538	xa_destroy(&port->endpoints);539	xa_destroy(&port->dports);540	xa_destroy(&port->regions);541	ida_free(&cxl_port_ida, port->id);542	if (is_cxl_root(port))543		kfree(to_cxl_root(port));544	else545		kfree(port);546}547 548static ssize_t decoders_committed_show(struct device *dev,549				       struct device_attribute *attr, char *buf)550{551	struct cxl_port *port = to_cxl_port(dev);552	int rc;553 554	down_read(&cxl_region_rwsem);555	rc = sysfs_emit(buf, "%d\n", cxl_num_decoders_committed(port));556	up_read(&cxl_region_rwsem);557 558	return rc;559}560 561static DEVICE_ATTR_RO(decoders_committed);562 563static struct attribute *cxl_port_attrs[] = {564	&dev_attr_decoders_committed.attr,565	NULL,566};567 568static struct attribute_group cxl_port_attribute_group = {569	.attrs = cxl_port_attrs,570};571 572static const struct attribute_group *cxl_port_attribute_groups[] = {573	&cxl_base_attribute_group,574	&cxl_port_attribute_group,575	NULL,576};577 578static const struct device_type cxl_port_type = {579	.name = "cxl_port",580	.release = cxl_port_release,581	.groups = cxl_port_attribute_groups,582};583 584bool is_cxl_port(const struct device *dev)585{586	return dev->type == &cxl_port_type;587}588EXPORT_SYMBOL_NS_GPL(is_cxl_port, CXL);589 590struct cxl_port *to_cxl_port(const struct device *dev)591{592	if (dev_WARN_ONCE(dev, dev->type != &cxl_port_type,593			  "not a cxl_port device\n"))594		return NULL;595	return container_of(dev, struct cxl_port, dev);596}597EXPORT_SYMBOL_NS_GPL(to_cxl_port, CXL);598 599static void unregister_port(void *_port)600{601	struct cxl_port *port = _port;602	struct cxl_port *parent;603	struct device *lock_dev;604 605	if (is_cxl_root(port))606		parent = NULL;607	else608		parent = to_cxl_port(port->dev.parent);609 610	/*611	 * CXL root port's and the first level of ports are unregistered612	 * under the platform firmware device lock, all other ports are613	 * unregistered while holding their parent port lock.614	 */615	if (!parent)616		lock_dev = port->uport_dev;617	else if (is_cxl_root(parent))618		lock_dev = parent->uport_dev;619	else620		lock_dev = &parent->dev;621 622	device_lock_assert(lock_dev);623	port->dead = true;624	device_unregister(&port->dev);625}626 627static void cxl_unlink_uport(void *_port)628{629	struct cxl_port *port = _port;630 631	sysfs_remove_link(&port->dev.kobj, "uport");632}633 634static int devm_cxl_link_uport(struct device *host, struct cxl_port *port)635{636	int rc;637 638	rc = sysfs_create_link(&port->dev.kobj, &port->uport_dev->kobj,639			       "uport");640	if (rc)641		return rc;642	return devm_add_action_or_reset(host, cxl_unlink_uport, port);643}644 645static void cxl_unlink_parent_dport(void *_port)646{647	struct cxl_port *port = _port;648 649	sysfs_remove_link(&port->dev.kobj, "parent_dport");650}651 652static int devm_cxl_link_parent_dport(struct device *host,653				      struct cxl_port *port,654				      struct cxl_dport *parent_dport)655{656	int rc;657 658	if (!parent_dport)659		return 0;660 661	rc = sysfs_create_link(&port->dev.kobj, &parent_dport->dport_dev->kobj,662			       "parent_dport");663	if (rc)664		return rc;665	return devm_add_action_or_reset(host, cxl_unlink_parent_dport, port);666}667 668static struct lock_class_key cxl_port_key;669 670static struct cxl_port *cxl_port_alloc(struct device *uport_dev,671				       struct cxl_dport *parent_dport)672{673	struct cxl_root *cxl_root __free(kfree) = NULL;674	struct cxl_port *port, *_port __free(kfree) = NULL;675	struct device *dev;676	int rc;677 678	/* No parent_dport, root cxl_port */679	if (!parent_dport) {680		cxl_root = kzalloc(sizeof(*cxl_root), GFP_KERNEL);681		if (!cxl_root)682			return ERR_PTR(-ENOMEM);683	} else {684		_port = kzalloc(sizeof(*port), GFP_KERNEL);685		if (!_port)686			return ERR_PTR(-ENOMEM);687	}688 689	rc = ida_alloc(&cxl_port_ida, GFP_KERNEL);690	if (rc < 0)691		return ERR_PTR(rc);692 693	if (cxl_root)694		port = &no_free_ptr(cxl_root)->port;695	else696		port = no_free_ptr(_port);697 698	port->id = rc;699	port->uport_dev = uport_dev;700 701	/*702	 * The top-level cxl_port "cxl_root" does not have a cxl_port as703	 * its parent and it does not have any corresponding component704	 * registers as its decode is described by a fixed platform705	 * description.706	 */707	dev = &port->dev;708	if (parent_dport) {709		struct cxl_port *parent_port = parent_dport->port;710		struct cxl_port *iter;711 712		dev->parent = &parent_port->dev;713		port->depth = parent_port->depth + 1;714		port->parent_dport = parent_dport;715 716		/*717		 * walk to the host bridge, or the first ancestor that knows718		 * the host bridge719		 */720		iter = port;721		while (!iter->host_bridge &&722		       !is_cxl_root(to_cxl_port(iter->dev.parent)))723			iter = to_cxl_port(iter->dev.parent);724		if (iter->host_bridge)725			port->host_bridge = iter->host_bridge;726		else if (parent_dport->rch)727			port->host_bridge = parent_dport->dport_dev;728		else729			port->host_bridge = iter->uport_dev;730		dev_dbg(uport_dev, "host-bridge: %s\n",731			dev_name(port->host_bridge));732	} else733		dev->parent = uport_dev;734 735	ida_init(&port->decoder_ida);736	port->hdm_end = -1;737	port->commit_end = -1;738	xa_init(&port->dports);739	xa_init(&port->endpoints);740	xa_init(&port->regions);741 742	device_initialize(dev);743	lockdep_set_class_and_subclass(&dev->mutex, &cxl_port_key, port->depth);744	device_set_pm_not_required(dev);745	dev->bus = &cxl_bus_type;746	dev->type = &cxl_port_type;747 748	return port;749}750 751static int cxl_setup_comp_regs(struct device *host, struct cxl_register_map *map,752			       resource_size_t component_reg_phys)753{754	*map = (struct cxl_register_map) {755		.host = host,756		.reg_type = CXL_REGLOC_RBI_EMPTY,757		.resource = component_reg_phys,758	};759 760	if (component_reg_phys == CXL_RESOURCE_NONE)761		return 0;762 763	map->reg_type = CXL_REGLOC_RBI_COMPONENT;764	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;765 766	return cxl_setup_regs(map);767}768 769static int cxl_port_setup_regs(struct cxl_port *port,770			resource_size_t component_reg_phys)771{772	if (dev_is_platform(port->uport_dev))773		return 0;774	return cxl_setup_comp_regs(&port->dev, &port->reg_map,775				   component_reg_phys);776}777 778static int cxl_dport_setup_regs(struct device *host, struct cxl_dport *dport,779				resource_size_t component_reg_phys)780{781	int rc;782 783	if (dev_is_platform(dport->dport_dev))784		return 0;785 786	/*787	 * use @dport->dport_dev for the context for error messages during788	 * register probing, and fixup @host after the fact, since @host may be789	 * NULL.790	 */791	rc = cxl_setup_comp_regs(dport->dport_dev, &dport->reg_map,792				 component_reg_phys);793	dport->reg_map.host = host;794	return rc;795}796 797DEFINE_SHOW_ATTRIBUTE(einj_cxl_available_error_type);798 799static int cxl_einj_inject(void *data, u64 type)800{801	struct cxl_dport *dport = data;802 803	if (dport->rch)804		return einj_cxl_inject_rch_error(dport->rcrb.base, type);805 806	return einj_cxl_inject_error(to_pci_dev(dport->dport_dev), type);807}808DEFINE_DEBUGFS_ATTRIBUTE(cxl_einj_inject_fops, NULL, cxl_einj_inject,809			 "0x%llx\n");810 811static void cxl_debugfs_create_dport_dir(struct cxl_dport *dport)812{813	struct dentry *dir;814 815	if (!einj_cxl_is_initialized())816		return;817 818	/*819	 * dport_dev needs to be a PCIe port for CXL 2.0+ ports because820	 * EINJ expects a dport SBDF to be specified for 2.0 error injection.821	 */822	if (!dport->rch && !dev_is_pci(dport->dport_dev))823		return;824 825	dir = cxl_debugfs_create_dir(dev_name(dport->dport_dev));826 827	debugfs_create_file("einj_inject", 0200, dir, dport,828			    &cxl_einj_inject_fops);829}830 831static int cxl_port_add(struct cxl_port *port,832			resource_size_t component_reg_phys,833			struct cxl_dport *parent_dport)834{835	struct device *dev __free(put_device) = &port->dev;836	int rc;837 838	if (is_cxl_memdev(port->uport_dev)) {839		struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);840		struct cxl_dev_state *cxlds = cxlmd->cxlds;841 842		rc = dev_set_name(dev, "endpoint%d", port->id);843		if (rc)844			return rc;845 846		/*847		 * The endpoint driver already enumerated the component and RAS848		 * registers. Reuse that enumeration while prepping them to be849		 * mapped by the cxl_port driver.850		 */851		port->reg_map = cxlds->reg_map;852		port->reg_map.host = &port->dev;853		cxlmd->endpoint = port;854	} else if (parent_dport) {855		rc = dev_set_name(dev, "port%d", port->id);856		if (rc)857			return rc;858 859		rc = cxl_port_setup_regs(port, component_reg_phys);860		if (rc)861			return rc;862	} else {863		rc = dev_set_name(dev, "root%d", port->id);864		if (rc)865			return rc;866	}867 868	rc = device_add(dev);869	if (rc)870		return rc;871 872	/* Inhibit the cleanup function invoked */873	dev = NULL;874	return 0;875}876 877static struct cxl_port *__devm_cxl_add_port(struct device *host,878					    struct device *uport_dev,879					    resource_size_t component_reg_phys,880					    struct cxl_dport *parent_dport)881{882	struct cxl_port *port;883	int rc;884 885	port = cxl_port_alloc(uport_dev, parent_dport);886	if (IS_ERR(port))887		return port;888 889	rc = cxl_port_add(port, component_reg_phys, parent_dport);890	if (rc)891		return ERR_PTR(rc);892 893	rc = devm_add_action_or_reset(host, unregister_port, port);894	if (rc)895		return ERR_PTR(rc);896 897	rc = devm_cxl_link_uport(host, port);898	if (rc)899		return ERR_PTR(rc);900 901	rc = devm_cxl_link_parent_dport(host, port, parent_dport);902	if (rc)903		return ERR_PTR(rc);904 905	if (parent_dport && dev_is_pci(uport_dev))906		port->pci_latency = cxl_pci_get_latency(to_pci_dev(uport_dev));907 908	return port;909}910 911/**912 * devm_cxl_add_port - register a cxl_port in CXL memory decode hierarchy913 * @host: host device for devm operations914 * @uport_dev: "physical" device implementing this upstream port915 * @component_reg_phys: (optional) for configurable cxl_port instances916 * @parent_dport: next hop up in the CXL memory decode hierarchy917 */918struct cxl_port *devm_cxl_add_port(struct device *host,919				   struct device *uport_dev,920				   resource_size_t component_reg_phys,921				   struct cxl_dport *parent_dport)922{923	struct cxl_port *port, *parent_port;924 925	port = __devm_cxl_add_port(host, uport_dev, component_reg_phys,926				   parent_dport);927 928	parent_port = parent_dport ? parent_dport->port : NULL;929	if (IS_ERR(port)) {930		dev_dbg(uport_dev, "Failed to add%s%s%s: %ld\n",931			parent_port ? " port to " : "",932			parent_port ? dev_name(&parent_port->dev) : "",933			parent_port ? "" : " root port",934			PTR_ERR(port));935	} else {936		dev_dbg(uport_dev, "%s added%s%s%s\n",937			dev_name(&port->dev),938			parent_port ? " to " : "",939			parent_port ? dev_name(&parent_port->dev) : "",940			parent_port ? "" : " (root port)");941	}942 943	return port;944}945EXPORT_SYMBOL_NS_GPL(devm_cxl_add_port, CXL);946 947struct cxl_root *devm_cxl_add_root(struct device *host,948				   const struct cxl_root_ops *ops)949{950	struct cxl_root *cxl_root;951	struct cxl_port *port;952 953	port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);954	if (IS_ERR(port))955		return ERR_CAST(port);956 957	cxl_root = to_cxl_root(port);958	cxl_root->ops = ops;959	return cxl_root;960}961EXPORT_SYMBOL_NS_GPL(devm_cxl_add_root, CXL);962 963struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port)964{965	/* There is no pci_bus associated with a CXL platform-root port */966	if (is_cxl_root(port))967		return NULL;968 969	if (dev_is_pci(port->uport_dev)) {970		struct pci_dev *pdev = to_pci_dev(port->uport_dev);971 972		return pdev->subordinate;973	}974 975	return xa_load(&cxl_root_buses, (unsigned long)port->uport_dev);976}977EXPORT_SYMBOL_NS_GPL(cxl_port_to_pci_bus, CXL);978 979static void unregister_pci_bus(void *uport_dev)980{981	xa_erase(&cxl_root_buses, (unsigned long)uport_dev);982}983 984int devm_cxl_register_pci_bus(struct device *host, struct device *uport_dev,985			      struct pci_bus *bus)986{987	int rc;988 989	if (dev_is_pci(uport_dev))990		return -EINVAL;991 992	rc = xa_insert(&cxl_root_buses, (unsigned long)uport_dev, bus,993		       GFP_KERNEL);994	if (rc)995		return rc;996	return devm_add_action_or_reset(host, unregister_pci_bus, uport_dev);997}998EXPORT_SYMBOL_NS_GPL(devm_cxl_register_pci_bus, CXL);999 1000static bool dev_is_cxl_root_child(struct device *dev)1001{1002	struct cxl_port *port, *parent;1003 1004	if (!is_cxl_port(dev))1005		return false;1006 1007	port = to_cxl_port(dev);1008	if (is_cxl_root(port))1009		return false;1010 1011	parent = to_cxl_port(port->dev.parent);1012	if (is_cxl_root(parent))1013		return true;1014 1015	return false;1016}1017 1018struct cxl_root *find_cxl_root(struct cxl_port *port)1019{1020	struct cxl_port *iter = port;1021 1022	while (iter && !is_cxl_root(iter))1023		iter = to_cxl_port(iter->dev.parent);1024 1025	if (!iter)1026		return NULL;1027	get_device(&iter->dev);1028	return to_cxl_root(iter);1029}1030EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL);1031 1032void put_cxl_root(struct cxl_root *cxl_root)1033{1034	if (!cxl_root)1035		return;1036 1037	put_device(&cxl_root->port.dev);1038}1039EXPORT_SYMBOL_NS_GPL(put_cxl_root, CXL);1040 1041static struct cxl_dport *find_dport(struct cxl_port *port, int id)1042{1043	struct cxl_dport *dport;1044	unsigned long index;1045 1046	device_lock_assert(&port->dev);1047	xa_for_each(&port->dports, index, dport)1048		if (dport->port_id == id)1049			return dport;1050	return NULL;1051}1052 1053static int add_dport(struct cxl_port *port, struct cxl_dport *dport)1054{1055	struct cxl_dport *dup;1056	int rc;1057 1058	device_lock_assert(&port->dev);1059	dup = find_dport(port, dport->port_id);1060	if (dup) {1061		dev_err(&port->dev,1062			"unable to add dport%d-%s non-unique port id (%s)\n",1063			dport->port_id, dev_name(dport->dport_dev),1064			dev_name(dup->dport_dev));1065		return -EBUSY;1066	}1067 1068	rc = xa_insert(&port->dports, (unsigned long)dport->dport_dev, dport,1069		       GFP_KERNEL);1070	if (rc)1071		return rc;1072 1073	port->nr_dports++;1074	return 0;1075}1076 1077/*1078 * Since root-level CXL dports cannot be enumerated by PCI they are not1079 * enumerated by the common port driver that acquires the port lock over1080 * dport add/remove. Instead, root dports are manually added by a1081 * platform driver and cond_cxl_root_lock() is used to take the missing1082 * port lock in that case.1083 */1084static void cond_cxl_root_lock(struct cxl_port *port)1085{1086	if (is_cxl_root(port))1087		device_lock(&port->dev);1088}1089 1090static void cond_cxl_root_unlock(struct cxl_port *port)1091{1092	if (is_cxl_root(port))1093		device_unlock(&port->dev);1094}1095 1096static void cxl_dport_remove(void *data)1097{1098	struct cxl_dport *dport = data;1099	struct cxl_port *port = dport->port;1100 1101	xa_erase(&port->dports, (unsigned long) dport->dport_dev);1102	put_device(dport->dport_dev);1103}1104 1105static void cxl_dport_unlink(void *data)1106{1107	struct cxl_dport *dport = data;1108	struct cxl_port *port = dport->port;1109	char link_name[CXL_TARGET_STRLEN];1110 1111	sprintf(link_name, "dport%d", dport->port_id);1112	sysfs_remove_link(&port->dev.kobj, link_name);1113}1114 1115static struct cxl_dport *1116__devm_cxl_add_dport(struct cxl_port *port, struct device *dport_dev,1117		     int port_id, resource_size_t component_reg_phys,1118		     resource_size_t rcrb)1119{1120	char link_name[CXL_TARGET_STRLEN];1121	struct cxl_dport *dport;1122	struct device *host;1123	int rc;1124 1125	if (is_cxl_root(port))1126		host = port->uport_dev;1127	else1128		host = &port->dev;1129 1130	if (!host->driver) {1131		dev_WARN_ONCE(&port->dev, 1, "dport:%s bad devm context\n",1132			      dev_name(dport_dev));1133		return ERR_PTR(-ENXIO);1134	}1135 1136	if (snprintf(link_name, CXL_TARGET_STRLEN, "dport%d", port_id) >=1137	    CXL_TARGET_STRLEN)1138		return ERR_PTR(-EINVAL);1139 1140	dport = devm_kzalloc(host, sizeof(*dport), GFP_KERNEL);1141	if (!dport)1142		return ERR_PTR(-ENOMEM);1143 1144	dport->dport_dev = dport_dev;1145	dport->port_id = port_id;1146	dport->port = port;1147 1148	if (rcrb == CXL_RESOURCE_NONE) {1149		rc = cxl_dport_setup_regs(&port->dev, dport,1150					  component_reg_phys);1151		if (rc)1152			return ERR_PTR(rc);1153	} else {1154		dport->rcrb.base = rcrb;1155		component_reg_phys = __rcrb_to_component(dport_dev, &dport->rcrb,1156							 CXL_RCRB_DOWNSTREAM);1157		if (component_reg_phys == CXL_RESOURCE_NONE) {1158			dev_warn(dport_dev, "Invalid Component Registers in RCRB");1159			return ERR_PTR(-ENXIO);1160		}1161 1162		/*1163		 * RCH @dport is not ready to map until associated with its1164		 * memdev1165		 */1166		rc = cxl_dport_setup_regs(NULL, dport, component_reg_phys);1167		if (rc)1168			return ERR_PTR(rc);1169 1170		dport->rch = true;1171	}1172 1173	if (component_reg_phys != CXL_RESOURCE_NONE)1174		dev_dbg(dport_dev, "Component Registers found for dport: %pa\n",1175			&component_reg_phys);1176 1177	cond_cxl_root_lock(port);1178	rc = add_dport(port, dport);1179	cond_cxl_root_unlock(port);1180	if (rc)1181		return ERR_PTR(rc);1182 1183	get_device(dport_dev);1184	rc = devm_add_action_or_reset(host, cxl_dport_remove, dport);1185	if (rc)1186		return ERR_PTR(rc);1187 1188	rc = sysfs_create_link(&port->dev.kobj, &dport_dev->kobj, link_name);1189	if (rc)1190		return ERR_PTR(rc);1191 1192	rc = devm_add_action_or_reset(host, cxl_dport_unlink, dport);1193	if (rc)1194		return ERR_PTR(rc);1195 1196	if (dev_is_pci(dport_dev))1197		dport->link_latency = cxl_pci_get_latency(to_pci_dev(dport_dev));1198 1199	cxl_debugfs_create_dport_dir(dport);1200 1201	return dport;1202}1203 1204/**1205 * devm_cxl_add_dport - append VH downstream port data to a cxl_port1206 * @port: the cxl_port that references this dport1207 * @dport_dev: firmware or PCI device representing the dport1208 * @port_id: identifier for this dport in a decoder's target list1209 * @component_reg_phys: optional location of CXL component registers1210 *1211 * Note that dports are appended to the devm release action's of the1212 * either the port's host (for root ports), or the port itself (for1213 * switch ports)1214 */1215struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,1216				     struct device *dport_dev, int port_id,1217				     resource_size_t component_reg_phys)1218{1219	struct cxl_dport *dport;1220 1221	dport = __devm_cxl_add_dport(port, dport_dev, port_id,1222				     component_reg_phys, CXL_RESOURCE_NONE);1223	if (IS_ERR(dport)) {1224		dev_dbg(dport_dev, "failed to add dport to %s: %ld\n",1225			dev_name(&port->dev), PTR_ERR(dport));1226	} else {1227		dev_dbg(dport_dev, "dport added to %s\n",1228			dev_name(&port->dev));1229	}1230 1231	return dport;1232}1233EXPORT_SYMBOL_NS_GPL(devm_cxl_add_dport, CXL);1234 1235/**1236 * devm_cxl_add_rch_dport - append RCH downstream port data to a cxl_port1237 * @port: the cxl_port that references this dport1238 * @dport_dev: firmware or PCI device representing the dport1239 * @port_id: identifier for this dport in a decoder's target list1240 * @rcrb: mandatory location of a Root Complex Register Block1241 *1242 * See CXL 3.0 9.11.8 CXL Devices Attached to an RCH1243 */1244struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,1245					 struct device *dport_dev, int port_id,1246					 resource_size_t rcrb)1247{1248	struct cxl_dport *dport;1249 1250	if (rcrb == CXL_RESOURCE_NONE) {1251		dev_dbg(&port->dev, "failed to add RCH dport, missing RCRB\n");1252		return ERR_PTR(-EINVAL);1253	}1254 1255	dport = __devm_cxl_add_dport(port, dport_dev, port_id,1256				     CXL_RESOURCE_NONE, rcrb);1257	if (IS_ERR(dport)) {1258		dev_dbg(dport_dev, "failed to add RCH dport to %s: %ld\n",1259			dev_name(&port->dev), PTR_ERR(dport));1260	} else {1261		dev_dbg(dport_dev, "RCH dport added to %s\n",1262			dev_name(&port->dev));1263	}1264 1265	return dport;1266}1267EXPORT_SYMBOL_NS_GPL(devm_cxl_add_rch_dport, CXL);1268 1269static int add_ep(struct cxl_ep *new)1270{1271	struct cxl_port *port = new->dport->port;1272 1273	guard(device)(&port->dev);1274	if (port->dead)1275		return -ENXIO;1276 1277	return xa_insert(&port->endpoints, (unsigned long)new->ep,1278			 new, GFP_KERNEL);1279}1280 1281/**1282 * cxl_add_ep - register an endpoint's interest in a port1283 * @dport: the dport that routes to @ep_dev1284 * @ep_dev: device representing the endpoint1285 *1286 * Intermediate CXL ports are scanned based on the arrival of endpoints.1287 * When those endpoints depart the port can be destroyed once all1288 * endpoints that care about that port have been removed.1289 */1290static int cxl_add_ep(struct cxl_dport *dport, struct device *ep_dev)1291{1292	struct cxl_ep *ep;1293	int rc;1294 1295	ep = kzalloc(sizeof(*ep), GFP_KERNEL);1296	if (!ep)1297		return -ENOMEM;1298 1299	ep->ep = get_device(ep_dev);1300	ep->dport = dport;1301 1302	rc = add_ep(ep);1303	if (rc)1304		cxl_ep_release(ep);1305	return rc;1306}1307 1308struct cxl_find_port_ctx {1309	const struct device *dport_dev;1310	const struct cxl_port *parent_port;1311	struct cxl_dport **dport;1312};1313 1314static int match_port_by_dport(struct device *dev, const void *data)1315{1316	const struct cxl_find_port_ctx *ctx = data;1317	struct cxl_dport *dport;1318	struct cxl_port *port;1319 1320	if (!is_cxl_port(dev))1321		return 0;1322	if (ctx->parent_port && dev->parent != &ctx->parent_port->dev)1323		return 0;1324 1325	port = to_cxl_port(dev);1326	dport = cxl_find_dport_by_dev(port, ctx->dport_dev);1327	if (ctx->dport)1328		*ctx->dport = dport;1329	return dport != NULL;1330}1331 1332static struct cxl_port *__find_cxl_port(struct cxl_find_port_ctx *ctx)1333{1334	struct device *dev;1335 1336	if (!ctx->dport_dev)1337		return NULL;1338 1339	dev = bus_find_device(&cxl_bus_type, NULL, ctx, match_port_by_dport);1340	if (dev)1341		return to_cxl_port(dev);1342	return NULL;1343}1344 1345static struct cxl_port *find_cxl_port(struct device *dport_dev,1346				      struct cxl_dport **dport)1347{1348	struct cxl_find_port_ctx ctx = {1349		.dport_dev = dport_dev,1350		.dport = dport,1351	};1352	struct cxl_port *port;1353 1354	port = __find_cxl_port(&ctx);1355	return port;1356}1357 1358static struct cxl_port *find_cxl_port_at(struct cxl_port *parent_port,1359					 struct device *dport_dev,1360					 struct cxl_dport **dport)1361{1362	struct cxl_find_port_ctx ctx = {1363		.dport_dev = dport_dev,1364		.parent_port = parent_port,1365		.dport = dport,1366	};1367	struct cxl_port *port;1368 1369	port = __find_cxl_port(&ctx);1370	return port;1371}1372 1373/*1374 * All users of grandparent() are using it to walk PCIe-like switch port1375 * hierarchy. A PCIe switch is comprised of a bridge device representing the1376 * upstream switch port and N bridges representing downstream switch ports. When1377 * bridges stack the grand-parent of a downstream switch port is another1378 * downstream switch port in the immediate ancestor switch.1379 */1380static struct device *grandparent(struct device *dev)1381{1382	if (dev && dev->parent)1383		return dev->parent->parent;1384	return NULL;1385}1386 1387static struct device *endpoint_host(struct cxl_port *endpoint)1388{1389	struct cxl_port *port = to_cxl_port(endpoint->dev.parent);1390 1391	if (is_cxl_root(port))1392		return port->uport_dev;1393	return &port->dev;1394}1395 1396static void delete_endpoint(void *data)1397{1398	struct cxl_memdev *cxlmd = data;1399	struct cxl_port *endpoint = cxlmd->endpoint;1400	struct device *host = endpoint_host(endpoint);1401 1402	scoped_guard(device, host) {1403		if (host->driver && !endpoint->dead) {1404			devm_release_action(host, cxl_unlink_parent_dport, endpoint);1405			devm_release_action(host, cxl_unlink_uport, endpoint);1406			devm_release_action(host, unregister_port, endpoint);1407		}1408		cxlmd->endpoint = NULL;1409	}1410	put_device(&endpoint->dev);1411	put_device(host);1412}1413 1414int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint)1415{1416	struct device *host = endpoint_host(endpoint);1417	struct device *dev = &cxlmd->dev;1418 1419	get_device(host);1420	get_device(&endpoint->dev);1421	cxlmd->depth = endpoint->depth;1422	return devm_add_action_or_reset(dev, delete_endpoint, cxlmd);1423}1424EXPORT_SYMBOL_NS_GPL(cxl_endpoint_autoremove, CXL);1425 1426/*1427 * The natural end of life of a non-root 'cxl_port' is when its parent port goes1428 * through a ->remove() event ("top-down" unregistration). The unnatural trigger1429 * for a port to be unregistered is when all memdevs beneath that port have gone1430 * through ->remove(). This "bottom-up" removal selectively removes individual1431 * child ports manually. This depends on devm_cxl_add_port() to not change is1432 * devm action registration order, and for dports to have already been1433 * destroyed by reap_dports().1434 */1435static void delete_switch_port(struct cxl_port *port)1436{1437	devm_release_action(port->dev.parent, cxl_unlink_parent_dport, port);1438	devm_release_action(port->dev.parent, cxl_unlink_uport, port);1439	devm_release_action(port->dev.parent, unregister_port, port);1440}1441 1442static void reap_dports(struct cxl_port *port)1443{1444	struct cxl_dport *dport;1445	unsigned long index;1446 1447	device_lock_assert(&port->dev);1448 1449	xa_for_each(&port->dports, index, dport) {1450		devm_release_action(&port->dev, cxl_dport_unlink, dport);1451		devm_release_action(&port->dev, cxl_dport_remove, dport);1452		devm_kfree(&port->dev, dport);1453	}1454}1455 1456struct detach_ctx {1457	struct cxl_memdev *cxlmd;1458	int depth;1459};1460 1461static int port_has_memdev(struct device *dev, const void *data)1462{1463	const struct detach_ctx *ctx = data;1464	struct cxl_port *port;1465 1466	if (!is_cxl_port(dev))1467		return 0;1468 1469	port = to_cxl_port(dev);1470	if (port->depth != ctx->depth)1471		return 0;1472 1473	return !!cxl_ep_load(port, ctx->cxlmd);1474}1475 1476static void cxl_detach_ep(void *data)1477{1478	struct cxl_memdev *cxlmd = data;1479 1480	for (int i = cxlmd->depth - 1; i >= 1; i--) {1481		struct cxl_port *port, *parent_port;1482		struct detach_ctx ctx = {1483			.cxlmd = cxlmd,1484			.depth = i,1485		};1486		struct cxl_ep *ep;1487		bool died = false;1488 1489		struct device *dev __free(put_device) =1490			bus_find_device(&cxl_bus_type, NULL, &ctx, port_has_memdev);1491		if (!dev)1492			continue;1493		port = to_cxl_port(dev);1494 1495		parent_port = to_cxl_port(port->dev.parent);1496		device_lock(&parent_port->dev);1497		device_lock(&port->dev);1498		ep = cxl_ep_load(port, cxlmd);1499		dev_dbg(&cxlmd->dev, "disconnect %s from %s\n",1500			ep ? dev_name(ep->ep) : "", dev_name(&port->dev));1501		cxl_ep_remove(port, ep);1502		if (ep && !port->dead && xa_empty(&port->endpoints) &&1503		    !is_cxl_root(parent_port) && parent_port->dev.driver) {1504			/*1505			 * This was the last ep attached to a dynamically1506			 * enumerated port. Block new cxl_add_ep() and garbage1507			 * collect the port.1508			 */1509			died = true;1510			port->dead = true;1511			reap_dports(port);1512		}1513		device_unlock(&port->dev);1514 1515		if (died) {1516			dev_dbg(&cxlmd->dev, "delete %s\n",1517				dev_name(&port->dev));1518			delete_switch_port(port);1519		}1520		device_unlock(&parent_port->dev);1521	}1522}1523 1524static resource_size_t find_component_registers(struct device *dev)1525{1526	struct cxl_register_map map;1527	struct pci_dev *pdev;1528 1529	/*1530	 * Theoretically, CXL component registers can be hosted on a1531	 * non-PCI device, in practice, only cxl_test hits this case.1532	 */1533	if (!dev_is_pci(dev))1534		return CXL_RESOURCE_NONE;1535 1536	pdev = to_pci_dev(dev);1537 1538	cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map);1539	return map.resource;1540}1541 1542static int add_port_attach_ep(struct cxl_memdev *cxlmd,1543			      struct device *uport_dev,1544			      struct device *dport_dev)1545{1546	struct device *dparent = grandparent(dport_dev);1547	struct cxl_dport *dport, *parent_dport;1548	resource_size_t component_reg_phys;1549	int rc;1550 1551	if (!dparent) {1552		/*1553		 * The iteration reached the topology root without finding the1554		 * CXL-root 'cxl_port' on a previous iteration, fail for now to1555		 * be re-probed after platform driver attaches.1556		 */1557		dev_dbg(&cxlmd->dev, "%s is a root dport\n",1558			dev_name(dport_dev));1559		return -ENXIO;1560	}1561 1562	struct cxl_port *parent_port __free(put_cxl_port) =1563		find_cxl_port(dparent, &parent_dport);1564	if (!parent_port) {1565		/* iterate to create this parent_port */1566		return -EAGAIN;1567	}1568 1569	/*1570	 * Definition with __free() here to keep the sequence of1571	 * dereferencing the device of the port before the parent_port releasing.1572	 */1573	struct cxl_port *port __free(put_cxl_port) = NULL;1574	scoped_guard(device, &parent_port->dev) {1575		if (!parent_port->dev.driver) {1576			dev_warn(&cxlmd->dev,1577				 "port %s:%s disabled, failed to enumerate CXL.mem\n",1578				 dev_name(&parent_port->dev), dev_name(uport_dev));1579			return -ENXIO;1580		}1581 1582		port = find_cxl_port_at(parent_port, dport_dev, &dport);1583		if (!port) {1584			component_reg_phys = find_component_registers(uport_dev);1585			port = devm_cxl_add_port(&parent_port->dev, uport_dev,1586						 component_reg_phys, parent_dport);1587			if (IS_ERR(port))1588				return PTR_ERR(port);1589 1590			/* retry find to pick up the new dport information */1591			port = find_cxl_port_at(parent_port, dport_dev, &dport);1592			if (!port)1593				return -ENXIO;1594		}1595	}1596 1597	dev_dbg(&cxlmd->dev, "add to new port %s:%s\n",1598		dev_name(&port->dev), dev_name(port->uport_dev));1599	rc = cxl_add_ep(dport, &cxlmd->dev);1600	if (rc == -EBUSY) {1601		/*1602		 * "can't" happen, but this error code means1603		 * something to the caller, so translate it.1604		 */1605		rc = -ENXIO;1606	}1607 1608	return rc;1609}1610 1611int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)1612{1613	struct device *dev = &cxlmd->dev;1614	struct device *iter;1615	int rc;1616 1617	/*1618	 * Skip intermediate port enumeration in the RCH case, there1619	 * are no ports in between a host bridge and an endpoint.1620	 */1621	if (cxlmd->cxlds->rcd)1622		return 0;1623 1624	rc = devm_add_action_or_reset(&cxlmd->dev, cxl_detach_ep, cxlmd);1625	if (rc)1626		return rc;1627 1628	/*1629	 * Scan for and add all cxl_ports in this device's ancestry.1630	 * Repeat until no more ports are added. Abort if a port add1631	 * attempt fails.1632	 */1633retry:1634	for (iter = dev; iter; iter = grandparent(iter)) {1635		struct device *dport_dev = grandparent(iter);1636		struct device *uport_dev;1637		struct cxl_dport *dport;1638 1639		/*1640		 * The terminal "grandparent" in PCI is NULL and @platform_bus1641		 * for platform devices1642		 */1643		if (!dport_dev || dport_dev == &platform_bus)1644			return 0;1645 1646		uport_dev = dport_dev->parent;1647		if (!uport_dev) {1648			dev_warn(dev, "at %s no parent for dport: %s\n",1649				 dev_name(iter), dev_name(dport_dev));1650			return -ENXIO;1651		}1652 1653		dev_dbg(dev, "scan: iter: %s dport_dev: %s parent: %s\n",1654			dev_name(iter), dev_name(dport_dev),1655			dev_name(uport_dev));1656		struct cxl_port *port __free(put_cxl_port) =1657			find_cxl_port(dport_dev, &dport);1658		if (port) {1659			dev_dbg(&cxlmd->dev,1660				"found already registered port %s:%s\n",1661				dev_name(&port->dev),1662				dev_name(port->uport_dev));1663			rc = cxl_add_ep(dport, &cxlmd->dev);1664 1665			/*1666			 * If the endpoint already exists in the port's list,1667			 * that's ok, it was added on a previous pass.1668			 * Otherwise, retry in add_port_attach_ep() after taking1669			 * the parent_port lock as the current port may be being1670			 * reaped.1671			 */1672			if (rc && rc != -EBUSY)1673				return rc;1674 1675			/* Any more ports to add between this one and the root? */1676			if (!dev_is_cxl_root_child(&port->dev))1677				continue;1678 1679			return 0;1680		}1681 1682		rc = add_port_attach_ep(cxlmd, uport_dev, dport_dev);1683		/* port missing, try to add parent */1684		if (rc == -EAGAIN)1685			continue;1686		/* failed to add ep or port */1687		if (rc)1688			return rc;1689		/* port added, new descendants possible, start over */1690		goto retry;1691	}1692 1693	return 0;1694}1695EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_ports, CXL);1696 1697struct cxl_port *cxl_pci_find_port(struct pci_dev *pdev,1698				   struct cxl_dport **dport)1699{1700	return find_cxl_port(pdev->dev.parent, dport);1701}1702EXPORT_SYMBOL_NS_GPL(cxl_pci_find_port, CXL);1703 1704struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,1705				   struct cxl_dport **dport)1706{1707	return find_cxl_port(grandparent(&cxlmd->dev), dport);1708}1709EXPORT_SYMBOL_NS_GPL(cxl_mem_find_port, CXL);1710 1711static int decoder_populate_targets(struct cxl_switch_decoder *cxlsd,1712				    struct cxl_port *port, int *target_map)1713{1714	int i;1715 1716	if (!target_map)1717		return 0;1718 1719	device_lock_assert(&port->dev);1720 1721	if (xa_empty(&port->dports))1722		return -EINVAL;1723 1724	guard(rwsem_write)(&cxl_region_rwsem);1725	for (i = 0; i < cxlsd->cxld.interleave_ways; i++) {1726		struct cxl_dport *dport = find_dport(port, target_map[i]);1727 1728		if (!dport)1729			return -ENXIO;1730		cxlsd->target[i] = dport;1731	}1732 1733	return 0;1734}1735 1736static struct lock_class_key cxl_decoder_key;1737 1738/**1739 * cxl_decoder_init - Common decoder setup / initialization1740 * @port: owning port of this decoder1741 * @cxld: common decoder properties to initialize1742 *1743 * A port may contain one or more decoders. Each of those decoders1744 * enable some address space for CXL.mem utilization. A decoder is1745 * expected to be configured by the caller before registering via1746 * cxl_decoder_add()1747 */1748static int cxl_decoder_init(struct cxl_port *port, struct cxl_decoder *cxld)1749{1750	struct device *dev;1751	int rc;1752 1753	rc = ida_alloc(&port->decoder_ida, GFP_KERNEL);1754	if (rc < 0)1755		return rc;1756 1757	/* need parent to stick around to release the id */1758	get_device(&port->dev);1759	cxld->id = rc;1760 1761	dev = &cxld->dev;1762	device_initialize(dev);1763	lockdep_set_class(&dev->mutex, &cxl_decoder_key);1764	device_set_pm_not_required(dev);1765	dev->parent = &port->dev;1766	dev->bus = &cxl_bus_type;1767 1768	/* Pre initialize an "empty" decoder */1769	cxld->interleave_ways = 1;1770	cxld->interleave_granularity = PAGE_SIZE;1771	cxld->target_type = CXL_DECODER_HOSTONLYMEM;1772	cxld->hpa_range = (struct range) {1773		.start = 0,1774		.end = -1,1775	};1776 1777	return 0;1778}1779 1780static int cxl_switch_decoder_init(struct cxl_port *port,1781				   struct cxl_switch_decoder *cxlsd,1782				   int nr_targets)1783{1784	if (nr_targets > CXL_DECODER_MAX_INTERLEAVE)1785		return -EINVAL;1786 1787	cxlsd->nr_targets = nr_targets;1788	return cxl_decoder_init(port, &cxlsd->cxld);1789}1790 1791/**1792 * cxl_root_decoder_alloc - Allocate a root level decoder1793 * @port: owning CXL root of this decoder1794 * @nr_targets: static number of downstream targets1795 *1796 * Return: A new cxl decoder to be registered by cxl_decoder_add(). A1797 * 'CXL root' decoder is one that decodes from a top-level / static platform1798 * firmware description of CXL resources into a CXL standard decode1799 * topology.1800 */1801struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,1802						unsigned int nr_targets)1803{1804	struct cxl_root_decoder *cxlrd;1805	struct cxl_switch_decoder *cxlsd;1806	struct cxl_decoder *cxld;1807	int rc;1808 1809	if (!is_cxl_root(port))1810		return ERR_PTR(-EINVAL);1811 1812	cxlrd = kzalloc(struct_size(cxlrd, cxlsd.target, nr_targets),1813			GFP_KERNEL);1814	if (!cxlrd)1815		return ERR_PTR(-ENOMEM);1816 1817	cxlsd = &cxlrd->cxlsd;1818	rc = cxl_switch_decoder_init(port, cxlsd, nr_targets);1819	if (rc) {1820		kfree(cxlrd);1821		return ERR_PTR(rc);1822	}1823 1824	mutex_init(&cxlrd->range_lock);1825 1826	cxld = &cxlsd->cxld;1827	cxld->dev.type = &cxl_decoder_root_type;1828	/*1829	 * cxl_root_decoder_release() special cases negative ids to1830	 * detect memregion_alloc() failures.1831	 */1832	atomic_set(&cxlrd->region_id, -1);1833	rc = memregion_alloc(GFP_KERNEL);1834	if (rc < 0) {1835		put_device(&cxld->dev);1836		return ERR_PTR(rc);1837	}1838 1839	atomic_set(&cxlrd->region_id, rc);1840	cxlrd->qos_class = CXL_QOS_CLASS_INVALID;1841	return cxlrd;1842}1843EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, CXL);1844 1845/**1846 * cxl_switch_decoder_alloc - Allocate a switch level decoder1847 * @port: owning CXL switch port of this decoder1848 * @nr_targets: max number of dynamically addressable downstream targets1849 *1850 * Return: A new cxl decoder to be registered by cxl_decoder_add(). A1851 * 'switch' decoder is any decoder that can be enumerated by PCIe1852 * topology and the HDM Decoder Capability. This includes the decoders1853 * that sit between Switch Upstream Ports / Switch Downstream Ports and1854 * Host Bridges / Root Ports.1855 */1856struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,1857						    unsigned int nr_targets)1858{1859	struct cxl_switch_decoder *cxlsd;1860	struct cxl_decoder *cxld;1861	int rc;1862 1863	if (is_cxl_root(port) || is_cxl_endpoint(port))1864		return ERR_PTR(-EINVAL);1865 1866	cxlsd = kzalloc(struct_size(cxlsd, target, nr_targets), GFP_KERNEL);1867	if (!cxlsd)1868		return ERR_PTR(-ENOMEM);1869 1870	rc = cxl_switch_decoder_init(port, cxlsd, nr_targets);1871	if (rc) {1872		kfree(cxlsd);1873		return ERR_PTR(rc);1874	}1875 1876	cxld = &cxlsd->cxld;1877	cxld->dev.type = &cxl_decoder_switch_type;1878	return cxlsd;1879}1880EXPORT_SYMBOL_NS_GPL(cxl_switch_decoder_alloc, CXL);1881 1882/**1883 * cxl_endpoint_decoder_alloc - Allocate an endpoint decoder1884 * @port: owning port of this decoder1885 *1886 * Return: A new cxl decoder to be registered by cxl_decoder_add()1887 */1888struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port)1889{1890	struct cxl_endpoint_decoder *cxled;1891	struct cxl_decoder *cxld;1892	int rc;1893 1894	if (!is_cxl_endpoint(port))1895		return ERR_PTR(-EINVAL);1896 1897	cxled = kzalloc(sizeof(*cxled), GFP_KERNEL);1898	if (!cxled)1899		return ERR_PTR(-ENOMEM);1900 1901	cxled->pos = -1;1902	cxld = &cxled->cxld;1903	rc = cxl_decoder_init(port, cxld);1904	if (rc)	 {1905		kfree(cxled);1906		return ERR_PTR(rc);1907	}1908 1909	cxld->dev.type = &cxl_decoder_endpoint_type;1910	return cxled;1911}1912EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_alloc, CXL);1913 1914/**1915 * cxl_decoder_add_locked - Add a decoder with targets1916 * @cxld: The cxl decoder allocated by cxl_<type>_decoder_alloc()1917 * @target_map: A list of downstream ports that this decoder can direct memory1918 *              traffic to. These numbers should correspond with the port number1919 *              in the PCIe Link Capabilities structure.1920 *1921 * Certain types of decoders may not have any targets. The main example of this1922 * is an endpoint device. A more awkward example is a hostbridge whose root1923 * ports get hot added (technically possible, though unlikely).1924 *1925 * This is the locked variant of cxl_decoder_add().1926 *1927 * Context: Process context. Expects the device lock of the port that owns the1928 *	    @cxld to be held.1929 *1930 * Return: Negative error code if the decoder wasn't properly configured; else1931 *	   returns 0.1932 */1933int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map)1934{1935	struct cxl_port *port;1936	struct device *dev;1937	int rc;1938 1939	if (WARN_ON_ONCE(!cxld))1940		return -EINVAL;1941 1942	if (WARN_ON_ONCE(IS_ERR(cxld)))1943		return PTR_ERR(cxld);1944 1945	if (cxld->interleave_ways < 1)1946		return -EINVAL;1947 1948	dev = &cxld->dev;1949 1950	port = to_cxl_port(cxld->dev.parent);1951	if (!is_endpoint_decoder(dev)) {1952		struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);1953 1954		rc = decoder_populate_targets(cxlsd, port, target_map);1955		if (rc && (cxld->flags & CXL_DECODER_F_ENABLE)) {1956			dev_err(&port->dev,1957				"Failed to populate active decoder targets\n");1958			return rc;1959		}1960	}1961 1962	rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id);1963	if (rc)1964		return rc;1965 1966	return device_add(dev);1967}1968EXPORT_SYMBOL_NS_GPL(cxl_decoder_add_locked, CXL);1969 1970/**1971 * cxl_decoder_add - Add a decoder with targets1972 * @cxld: The cxl decoder allocated by cxl_<type>_decoder_alloc()1973 * @target_map: A list of downstream ports that this decoder can direct memory1974 *              traffic to. These numbers should correspond with the port number1975 *              in the PCIe Link Capabilities structure.1976 *1977 * This is the unlocked variant of cxl_decoder_add_locked().1978 * See cxl_decoder_add_locked().1979 *1980 * Context: Process context. Takes and releases the device lock of the port that1981 *	    owns the @cxld.1982 */1983int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map)1984{1985	struct cxl_port *port;1986 1987	if (WARN_ON_ONCE(!cxld))1988		return -EINVAL;1989 1990	if (WARN_ON_ONCE(IS_ERR(cxld)))1991		return PTR_ERR(cxld);1992 1993	port = to_cxl_port(cxld->dev.parent);1994 1995	guard(device)(&port->dev);1996	return cxl_decoder_add_locked(cxld, target_map);1997}1998EXPORT_SYMBOL_NS_GPL(cxl_decoder_add, CXL);1999 2000static void cxld_unregister(void *dev)2001{2002	struct cxl_endpoint_decoder *cxled;2003 2004	if (is_endpoint_decoder(dev)) {2005		cxled = to_cxl_endpoint_decoder(dev);2006		cxl_decoder_kill_region(cxled);2007	}2008 2009	device_unregister(dev);2010}2011 2012int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld)2013{2014	return devm_add_action_or_reset(host, cxld_unregister, &cxld->dev);2015}2016EXPORT_SYMBOL_NS_GPL(cxl_decoder_autoremove, CXL);2017 2018/**2019 * __cxl_driver_register - register a driver for the cxl bus2020 * @cxl_drv: cxl driver structure to attach2021 * @owner: owning module/driver2022 * @modname: KBUILD_MODNAME for parent driver2023 */2024int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,2025			  const char *modname)2026{2027	if (!cxl_drv->probe) {2028		pr_debug("%s ->probe() must be specified\n", modname);2029		return -EINVAL;2030	}2031 2032	if (!cxl_drv->name) {2033		pr_debug("%s ->name must be specified\n", modname);2034		return -EINVAL;2035	}2036 2037	if (!cxl_drv->id) {2038		pr_debug("%s ->id must be specified\n", modname);2039		return -EINVAL;2040	}2041 2042	cxl_drv->drv.bus = &cxl_bus_type;2043	cxl_drv->drv.owner = owner;2044	cxl_drv->drv.mod_name = modname;2045	cxl_drv->drv.name = cxl_drv->name;2046 2047	return driver_register(&cxl_drv->drv);2048}2049EXPORT_SYMBOL_NS_GPL(__cxl_driver_register, CXL);2050 2051void cxl_driver_unregister(struct cxl_driver *cxl_drv)2052{2053	driver_unregister(&cxl_drv->drv);2054}2055EXPORT_SYMBOL_NS_GPL(cxl_driver_unregister, CXL);2056 2057static int cxl_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)2058{2059	return add_uevent_var(env, "MODALIAS=" CXL_MODALIAS_FMT,2060			      cxl_device_id(dev));2061}2062 2063static int cxl_bus_match(struct device *dev, const struct device_driver *drv)2064{2065	return cxl_device_id(dev) == to_cxl_drv(drv)->id;2066}2067 2068static int cxl_bus_probe(struct device *dev)2069{2070	int rc;2071 2072	rc = to_cxl_drv(dev->driver)->probe(dev);2073	dev_dbg(dev, "probe: %d\n", rc);2074	return rc;2075}2076 2077static void cxl_bus_remove(struct device *dev)2078{2079	struct cxl_driver *cxl_drv = to_cxl_drv(dev->driver);2080 2081	if (cxl_drv->remove)2082		cxl_drv->remove(dev);2083}2084 2085static struct workqueue_struct *cxl_bus_wq;2086 2087static int cxl_rescan_attach(struct device *dev, void *data)2088{2089	int rc = device_attach(dev);2090 2091	dev_vdbg(dev, "rescan: %s\n", rc ? "attach" : "detached");2092 2093	return 0;2094}2095 2096static void cxl_bus_rescan_queue(struct work_struct *w)2097{2098	bus_for_each_dev(&cxl_bus_type, NULL, NULL, cxl_rescan_attach);2099}2100 2101void cxl_bus_rescan(void)2102{2103	static DECLARE_WORK(rescan_work, cxl_bus_rescan_queue);2104 2105	queue_work(cxl_bus_wq, &rescan_work);2106}2107EXPORT_SYMBOL_NS_GPL(cxl_bus_rescan, CXL);2108 2109void cxl_bus_drain(void)2110{2111	drain_workqueue(cxl_bus_wq);2112}2113EXPORT_SYMBOL_NS_GPL(cxl_bus_drain, CXL);2114 2115bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd)2116{2117	return queue_work(cxl_bus_wq, &cxlmd->detach_work);2118}2119EXPORT_SYMBOL_NS_GPL(schedule_cxl_memdev_detach, CXL);2120 2121static void add_latency(struct access_coordinate *c, long latency)2122{2123	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {2124		c[i].write_latency += latency;2125		c[i].read_latency += latency;2126	}2127}2128 2129static bool coordinates_valid(struct access_coordinate *c)2130{2131	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {2132		if (c[i].read_bandwidth && c[i].write_bandwidth &&2133		    c[i].read_latency && c[i].write_latency)2134			continue;2135		return false;2136	}2137 2138	return true;2139}2140 2141static void set_min_bandwidth(struct access_coordinate *c, unsigned int bw)2142{2143	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {2144		c[i].write_bandwidth = min(c[i].write_bandwidth, bw);2145		c[i].read_bandwidth = min(c[i].read_bandwidth, bw);2146	}2147}2148 2149static void set_access_coordinates(struct access_coordinate *out,2150				   struct access_coordinate *in)2151{2152	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++)2153		out[i] = in[i];2154}2155 2156static bool parent_port_is_cxl_root(struct cxl_port *port)2157{2158	return is_cxl_root(to_cxl_port(port->dev.parent));2159}2160 2161/**2162 * cxl_endpoint_get_perf_coordinates - Retrieve performance numbers stored in dports2163 *				   of CXL path2164 * @port: endpoint cxl_port2165 * @coord: output performance data2166 *2167 * Return: errno on failure, 0 on success.2168 */2169int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,2170				      struct access_coordinate *coord)2171{2172	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);2173	struct access_coordinate c[] = {2174		{2175			.read_bandwidth = UINT_MAX,2176			.write_bandwidth = UINT_MAX,2177		},2178		{2179			.read_bandwidth = UINT_MAX,2180			.write_bandwidth = UINT_MAX,2181		},2182	};2183	struct cxl_port *iter = port;2184	struct cxl_dport *dport;2185	struct pci_dev *pdev;2186	struct device *dev;2187	unsigned int bw;2188	bool is_cxl_root;2189 2190	if (!is_cxl_endpoint(port))2191		return -EINVAL;2192 2193	/*2194	 * Skip calculation for RCD. Expectation is HMAT already covers RCD case2195	 * since RCH does not support hotplug.2196	 */2197	if (cxlmd->cxlds->rcd)2198		return 0;2199 2200	/*2201	 * Exit the loop when the parent port of the current iter port is cxl2202	 * root. The iterative loop starts at the endpoint and gathers the2203	 * latency of the CXL link from the current device/port to the connected2204	 * downstream port each iteration.2205	 */2206	do {2207		dport = iter->parent_dport;2208		iter = to_cxl_port(iter->dev.parent);2209		is_cxl_root = parent_port_is_cxl_root(iter);2210 2211		/*2212		 * There's no valid access_coordinate for a root port since RPs do not2213		 * have CDAT and therefore needs to be skipped.2214		 */2215		if (!is_cxl_root) {2216			if (!coordinates_valid(dport->coord))2217				return -EINVAL;2218			cxl_coordinates_combine(c, c, dport->coord);2219		}2220		add_latency(c, dport->link_latency);2221	} while (!is_cxl_root);2222 2223	dport = iter->parent_dport;2224	/* Retrieve HB coords */2225	if (!coordinates_valid(dport->coord))2226		return -EINVAL;2227	cxl_coordinates_combine(c, c, dport->coord);2228 2229	dev = port->uport_dev->parent;2230	if (!dev_is_pci(dev))2231		return -ENODEV;2232 2233	/* Get the calculated PCI paths bandwidth */2234	pdev = to_pci_dev(dev);2235	bw = pcie_bandwidth_available(pdev, NULL, NULL, NULL);2236	if (bw == 0)2237		return -ENXIO;2238	bw /= BITS_PER_BYTE;2239 2240	set_min_bandwidth(c, bw);2241	set_access_coordinates(coord, c);2242 2243	return 0;2244}2245EXPORT_SYMBOL_NS_GPL(cxl_endpoint_get_perf_coordinates, CXL);2246 2247int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,2248					struct access_coordinate *c)2249{2250	struct cxl_dport *dport = port->parent_dport;2251 2252	/* Check this port is connected to a switch DSP and not an RP */2253	if (parent_port_is_cxl_root(to_cxl_port(port->dev.parent)))2254		return -ENODEV;2255 2256	if (!coordinates_valid(dport->coord))2257		return -EINVAL;2258 2259	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {2260		c[i].read_bandwidth = dport->coord[i].read_bandwidth;2261		c[i].write_bandwidth = dport->coord[i].write_bandwidth;2262	}2263 2264	return 0;2265}2266 2267/* for user tooling to ensure port disable work has completed */2268static ssize_t flush_store(const struct bus_type *bus, const char *buf, size_t count)2269{2270	if (sysfs_streq(buf, "1")) {2271		flush_workqueue(cxl_bus_wq);2272		return count;2273	}2274 2275	return -EINVAL;2276}2277 2278static BUS_ATTR_WO(flush);2279 2280static struct attribute *cxl_bus_attributes[] = {2281	&bus_attr_flush.attr,2282	NULL,2283};2284 2285static struct attribute_group cxl_bus_attribute_group = {2286	.attrs = cxl_bus_attributes,2287};2288 2289static const struct attribute_group *cxl_bus_attribute_groups[] = {2290	&cxl_bus_attribute_group,2291	NULL,2292};2293 2294struct bus_type cxl_bus_type = {2295	.name = "cxl",2296	.uevent = cxl_bus_uevent,2297	.match = cxl_bus_match,2298	.probe = cxl_bus_probe,2299	.remove = cxl_bus_remove,2300	.bus_groups = cxl_bus_attribute_groups,2301};2302EXPORT_SYMBOL_NS_GPL(cxl_bus_type, CXL);2303 2304static struct dentry *cxl_debugfs;2305 2306struct dentry *cxl_debugfs_create_dir(const char *dir)2307{2308	return debugfs_create_dir(dir, cxl_debugfs);2309}2310EXPORT_SYMBOL_NS_GPL(cxl_debugfs_create_dir, CXL);2311 2312static __init int cxl_core_init(void)2313{2314	int rc;2315 2316	cxl_debugfs = debugfs_create_dir("cxl", NULL);2317 2318	if (einj_cxl_is_initialized())2319		debugfs_create_file("einj_types", 0400, cxl_debugfs, NULL,2320				    &einj_cxl_available_error_type_fops);2321 2322	cxl_mbox_init();2323 2324	rc = cxl_memdev_init();2325	if (rc)2326		return rc;2327 2328	cxl_bus_wq = alloc_ordered_workqueue("cxl_port", 0);2329	if (!cxl_bus_wq) {2330		rc = -ENOMEM;2331		goto err_wq;2332	}2333 2334	rc = bus_register(&cxl_bus_type);2335	if (rc)2336		goto err_bus;2337 2338	rc = cxl_region_init();2339	if (rc)2340		goto err_region;2341 2342	return 0;2343 2344err_region:2345	bus_unregister(&cxl_bus_type);2346err_bus:2347	destroy_workqueue(cxl_bus_wq);2348err_wq:2349	cxl_memdev_exit();2350	return rc;2351}2352 2353static void cxl_core_exit(void)2354{2355	cxl_region_exit();2356	bus_unregister(&cxl_bus_type);2357	destroy_workqueue(cxl_bus_wq);2358	cxl_memdev_exit();2359	debugfs_remove_recursive(cxl_debugfs);2360}2361 2362subsys_initcall(cxl_core_init);2363module_exit(cxl_core_exit);2364MODULE_DESCRIPTION("CXL: Core Compute Express Link support");2365MODULE_LICENSE("GPL v2");2366MODULE_IMPORT_NS(CXL);2367