1// SPDX-License-Identifier: GPL-2.0-only
   2/* 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 core
  21 *
  22 * The CXL core provides a set of interfaces that can be consumed by CXL aware
  23 * drivers. The interfaces allow for creation, modification, and destruction of
  24 * regions, memory devices, ports, and decoders. CXL aware drivers must register
  25 * with the CXL core via these interfaces in order to be able to participate in
  26 * cross-device interleave coordination. The CXL core also establishes and
  27 * maintains the bridge to the nvdimm subsystem.
  28 *
  29 * CXL core introduces sysfs hierarchy to control the devices that are
  30 * instantiated by the core.
  31 */
  32
  33/*
  34 * All changes to the interleave configuration occur with this lock held
  35 * 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	else
 213		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	else
 545		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	else
 608		parent = to_cxl_port(port->dev.parent);
 609
 610	/*
 611	 * CXL root port's and the first level of ports are unregistered
 612	 * under the platform firmware device lock, all other ports are
 613	 * 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	else
 620		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	else
 696		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 as
 703	 * its parent and it does not have any corresponding component
 704	 * registers as its decode is described by a fixed platform
 705	 * 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 knows
 718		 * the host bridge
 719		 */
 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		else
 729			port->host_bridge = iter->uport_dev;
 730		dev_dbg(uport_dev, "host-bridge: %s\n",
 731			dev_name(port->host_bridge));
 732	} else
 733		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 during
 788	 * register probing, and fixup @host after the fact, since @host may be
 789	 * 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 because
 820	 * 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 RAS
 848		 * registers. Reuse that enumeration while prepping them to be
 849		 * 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 hierarchy
 913 * @host: host device for devm operations
 914 * @uport_dev: "physical" device implementing this upstream port
 915 * @component_reg_phys: (optional) for configurable cxl_port instances
 916 * @parent_dport: next hop up in the CXL memory decode hierarchy
 917 */
 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 not
1079 * enumerated by the common port driver that acquires the port lock over
1080 * dport add/remove. Instead, root dports are manually added by a
1081 * platform driver and cond_cxl_root_lock() is used to take the missing
1082 * 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	else
1128		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 its
1164		 * memdev
1165		 */
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_port
1206 * @port: the cxl_port that references this dport
1207 * @dport_dev: firmware or PCI device representing the dport
1208 * @port_id: identifier for this dport in a decoder's target list
1209 * @component_reg_phys: optional location of CXL component registers
1210 *
1211 * Note that dports are appended to the devm release action's of the
1212 * either the port's host (for root ports), or the port itself (for
1213 * 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_port
1237 * @port: the cxl_port that references this dport
1238 * @dport_dev: firmware or PCI device representing the dport
1239 * @port_id: identifier for this dport in a decoder's target list
1240 * @rcrb: mandatory location of a Root Complex Register Block
1241 *
1242 * See CXL 3.0 9.11.8 CXL Devices Attached to an RCH
1243 */
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 port
1283 * @dport: the dport that routes to @ep_dev
1284 * @ep_dev: device representing the endpoint
1285 *
1286 * Intermediate CXL ports are scanned based on the arrival of endpoints.
1287 * When those endpoints depart the port can be destroyed once all
1288 * 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 port
1375 * hierarchy. A PCIe switch is comprised of a bridge device representing the
1376 * upstream switch port and N bridges representing downstream switch ports. When
1377 * bridges stack the grand-parent of a downstream switch port is another
1378 * 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 goes
1428 * through a ->remove() event ("top-down" unregistration). The unnatural trigger
1429 * for a port to be unregistered is when all memdevs beneath that port have gone
1430 * through ->remove(). This "bottom-up" removal selectively removes individual
1431 * child ports manually. This depends on devm_cxl_add_port() to not change is
1432 * devm action registration order, and for dports to have already been
1433 * 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 dynamically
1506			 * enumerated port. Block new cxl_add_ep() and garbage
1507			 * 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 a
1531	 * 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 the
1554		 * CXL-root 'cxl_port' on a previous iteration, fail for now to
1555		 * 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 of
1571	 * 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 means
1603		 * 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, there
1619	 * 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 add
1631	 * 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_bus
1641		 * for platform devices
1642		 */
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 taking
1669			 * the parent_port lock as the current port may be being
1670			 * 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 / initialization
1740 * @port: owning port of this decoder
1741 * @cxld: common decoder properties to initialize
1742 *
1743 * A port may contain one or more decoders. Each of those decoders
1744 * enable some address space for CXL.mem utilization. A decoder is
1745 * expected to be configured by the caller before registering via
1746 * 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 decoder
1793 * @port: owning CXL root of this decoder
1794 * @nr_targets: static number of downstream targets
 
1795 *
1796 * Return: A new cxl decoder to be registered by cxl_decoder_add(). A
1797 * 'CXL root' decoder is one that decodes from a top-level / static platform
1798 * firmware description of CXL resources into a CXL standard decode
1799 * 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 to
1830	 * 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 decoder
1847 * @port: owning CXL switch port of this decoder
1848 * @nr_targets: max number of dynamically addressable downstream targets
1849 *
1850 * Return: A new cxl decoder to be registered by cxl_decoder_add(). A
1851 * 'switch' decoder is any decoder that can be enumerated by PCIe
1852 * topology and the HDM Decoder Capability. This includes the decoders
1853 * that sit between Switch Upstream Ports / Switch Downstream Ports and
1854 * 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 decoder
1884 * @port: owning port of this decoder
1885 *
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 targets
1916 * @cxld: The cxl decoder allocated by cxl_<type>_decoder_alloc()
1917 * @target_map: A list of downstream ports that this decoder can direct memory
1918 *              traffic to. These numbers should correspond with the port number
1919 *              in the PCIe Link Capabilities structure.
1920 *
1921 * Certain types of decoders may not have any targets. The main example of this
1922 * is an endpoint device. A more awkward example is a hostbridge whose root
1923 * 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 the
1928 *	    @cxld to be held.
1929 *
1930 * Return: Negative error code if the decoder wasn't properly configured; else
1931 *	   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 targets
1972 * @cxld: The cxl decoder allocated by cxl_<type>_decoder_alloc()
1973 * @target_map: A list of downstream ports that this decoder can direct memory
1974 *              traffic to. These numbers should correspond with the port number
1975 *              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 that
1981 *	    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 bus
2020 * @cxl_drv: cxl driver structure to attach
2021 * @owner: owning module/driver
2022 * @modname: KBUILD_MODNAME for parent driver
2023 */
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 dports
2163 *				   of CXL path
2164 * @port: endpoint cxl_port
2165 * @coord: output performance data
2166 *
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 case
2195	 * 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 cxl
2202	 * root. The iterative loop starts at the endpoint and gathers the
2203	 * latency of the CXL link from the current device/port to the connected
2204	 * 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 not
2213		 * 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");