xref: /openbmc/linux/drivers/cxl/acpi.c (revision cc698db4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2021 Intel Corporation. All rights reserved. */
3 #include <linux/platform_device.h>
4 #include <linux/module.h>
5 #include <linux/device.h>
6 #include <linux/kernel.h>
7 #include <linux/acpi.h>
8 #include <linux/pci.h>
9 #include <asm/div64.h>
10 #include "cxlpci.h"
11 #include "cxl.h"
12 
13 #define CXL_RCRB_SIZE	SZ_8K
14 
15 struct cxl_cxims_data {
16 	int nr_maps;
17 	u64 xormaps[] __counted_by(nr_maps);
18 };
19 
20 /*
21  * Find a targets entry (n) in the host bridge interleave list.
22  * CXL Specification 3.0 Table 9-22
23  */
24 static int cxl_xor_calc_n(u64 hpa, struct cxl_cxims_data *cximsd, int iw,
25 			  int ig)
26 {
27 	int i = 0, n = 0;
28 	u8 eiw;
29 
30 	/* IW: 2,4,6,8,12,16 begin building 'n' using xormaps */
31 	if (iw != 3) {
32 		for (i = 0; i < cximsd->nr_maps; i++)
33 			n |= (hweight64(hpa & cximsd->xormaps[i]) & 1) << i;
34 	}
35 	/* IW: 3,6,12 add a modulo calculation to 'n' */
36 	if (!is_power_of_2(iw)) {
37 		if (ways_to_eiw(iw, &eiw))
38 			return -1;
39 		hpa &= GENMASK_ULL(51, eiw + ig);
40 		n |= do_div(hpa, 3) << i;
41 	}
42 	return n;
43 }
44 
45 static struct cxl_dport *cxl_hb_xor(struct cxl_root_decoder *cxlrd, int pos)
46 {
47 	struct cxl_cxims_data *cximsd = cxlrd->platform_data;
48 	struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd;
49 	struct cxl_decoder *cxld = &cxlsd->cxld;
50 	int ig = cxld->interleave_granularity;
51 	int iw = cxld->interleave_ways;
52 	int n = 0;
53 	u64 hpa;
54 
55 	if (dev_WARN_ONCE(&cxld->dev,
56 			  cxld->interleave_ways != cxlsd->nr_targets,
57 			  "misconfigured root decoder\n"))
58 		return NULL;
59 
60 	hpa = cxlrd->res->start + pos * ig;
61 
62 	/* Entry (n) is 0 for no interleave (iw == 1) */
63 	if (iw != 1)
64 		n = cxl_xor_calc_n(hpa, cximsd, iw, ig);
65 
66 	if (n < 0)
67 		return NULL;
68 
69 	return cxlrd->cxlsd.target[n];
70 }
71 
72 struct cxl_cxims_context {
73 	struct device *dev;
74 	struct cxl_root_decoder *cxlrd;
75 };
76 
77 static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
78 			   const unsigned long end)
79 {
80 	struct acpi_cedt_cxims *cxims = (struct acpi_cedt_cxims *)header;
81 	struct cxl_cxims_context *ctx = arg;
82 	struct cxl_root_decoder *cxlrd = ctx->cxlrd;
83 	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
84 	struct device *dev = ctx->dev;
85 	struct cxl_cxims_data *cximsd;
86 	unsigned int hbig, nr_maps;
87 	int rc;
88 
89 	rc = eig_to_granularity(cxims->hbig, &hbig);
90 	if (rc)
91 		return rc;
92 
93 	/* Does this CXIMS entry apply to the given CXL Window? */
94 	if (hbig != cxld->interleave_granularity)
95 		return 0;
96 
97 	/* IW 1,3 do not use xormaps and skip this parsing entirely */
98 	if (is_power_of_2(cxld->interleave_ways))
99 		/* 2, 4, 8, 16 way */
100 		nr_maps = ilog2(cxld->interleave_ways);
101 	else
102 		/* 6, 12 way */
103 		nr_maps = ilog2(cxld->interleave_ways / 3);
104 
105 	if (cxims->nr_xormaps < nr_maps) {
106 		dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n",
107 			cxims->nr_xormaps, nr_maps);
108 		return -ENXIO;
109 	}
110 
111 	cximsd = devm_kzalloc(dev, struct_size(cximsd, xormaps, nr_maps),
112 			      GFP_KERNEL);
113 	if (!cximsd)
114 		return -ENOMEM;
115 	cximsd->nr_maps = nr_maps;
116 	memcpy(cximsd->xormaps, cxims->xormap_list,
117 	       nr_maps * sizeof(*cximsd->xormaps));
118 	cxlrd->platform_data = cximsd;
119 
120 	return 0;
121 }
122 
123 static unsigned long cfmws_to_decoder_flags(int restrictions)
124 {
125 	unsigned long flags = CXL_DECODER_F_ENABLE;
126 
127 	if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2)
128 		flags |= CXL_DECODER_F_TYPE2;
129 	if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3)
130 		flags |= CXL_DECODER_F_TYPE3;
131 	if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE)
132 		flags |= CXL_DECODER_F_RAM;
133 	if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM)
134 		flags |= CXL_DECODER_F_PMEM;
135 	if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED)
136 		flags |= CXL_DECODER_F_LOCK;
137 
138 	return flags;
139 }
140 
141 static int cxl_acpi_cfmws_verify(struct device *dev,
142 				 struct acpi_cedt_cfmws *cfmws)
143 {
144 	int rc, expected_len;
145 	unsigned int ways;
146 
147 	if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO &&
148 	    cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
149 		dev_err(dev, "CFMWS Unknown Interleave Arithmetic: %d\n",
150 			cfmws->interleave_arithmetic);
151 		return -EINVAL;
152 	}
153 
154 	if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) {
155 		dev_err(dev, "CFMWS Base HPA not 256MB aligned\n");
156 		return -EINVAL;
157 	}
158 
159 	if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) {
160 		dev_err(dev, "CFMWS Window Size not 256MB aligned\n");
161 		return -EINVAL;
162 	}
163 
164 	rc = eiw_to_ways(cfmws->interleave_ways, &ways);
165 	if (rc) {
166 		dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n",
167 			cfmws->interleave_ways);
168 		return -EINVAL;
169 	}
170 
171 	expected_len = struct_size(cfmws, interleave_targets, ways);
172 
173 	if (cfmws->header.length < expected_len) {
174 		dev_err(dev, "CFMWS length %d less than expected %d\n",
175 			cfmws->header.length, expected_len);
176 		return -EINVAL;
177 	}
178 
179 	if (cfmws->header.length > expected_len)
180 		dev_dbg(dev, "CFMWS length %d greater than expected %d\n",
181 			cfmws->header.length, expected_len);
182 
183 	return 0;
184 }
185 
186 /*
187  * Note, @dev must be the first member, see 'struct cxl_chbs_context'
188  * and mock_acpi_table_parse_cedt()
189  */
190 struct cxl_cfmws_context {
191 	struct device *dev;
192 	struct cxl_port *root_port;
193 	struct resource *cxl_res;
194 	int id;
195 };
196 
197 static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
198 			     struct cxl_cfmws_context *ctx)
199 {
200 	int target_map[CXL_DECODER_MAX_INTERLEAVE];
201 	struct cxl_port *root_port = ctx->root_port;
202 	struct resource *cxl_res = ctx->cxl_res;
203 	struct cxl_cxims_context cxims_ctx;
204 	struct cxl_root_decoder *cxlrd;
205 	struct device *dev = ctx->dev;
206 	cxl_calc_hb_fn cxl_calc_hb;
207 	struct cxl_decoder *cxld;
208 	unsigned int ways, i, ig;
209 	struct resource *res;
210 	int rc;
211 
212 	rc = cxl_acpi_cfmws_verify(dev, cfmws);
213 	if (rc) {
214 		dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
215 			cfmws->base_hpa,
216 			cfmws->base_hpa + cfmws->window_size - 1);
217 		return rc;
218 	}
219 
220 	rc = eiw_to_ways(cfmws->interleave_ways, &ways);
221 	if (rc)
222 		return rc;
223 	rc = eig_to_granularity(cfmws->granularity, &ig);
224 	if (rc)
225 		return rc;
226 	for (i = 0; i < ways; i++)
227 		target_map[i] = cfmws->interleave_targets[i];
228 
229 	res = kzalloc(sizeof(*res), GFP_KERNEL);
230 	if (!res)
231 		return -ENOMEM;
232 
233 	res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++);
234 	if (!res->name)
235 		goto err_name;
236 
237 	res->start = cfmws->base_hpa;
238 	res->end = cfmws->base_hpa + cfmws->window_size - 1;
239 	res->flags = IORESOURCE_MEM;
240 
241 	/* add to the local resource tracking to establish a sort order */
242 	rc = insert_resource(cxl_res, res);
243 	if (rc)
244 		goto err_insert;
245 
246 	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO)
247 		cxl_calc_hb = cxl_hb_modulo;
248 	else
249 		cxl_calc_hb = cxl_hb_xor;
250 
251 	cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
252 	if (IS_ERR(cxlrd))
253 		return PTR_ERR(cxlrd);
254 
255 	cxld = &cxlrd->cxlsd.cxld;
256 	cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
257 	cxld->target_type = CXL_DECODER_HOSTONLYMEM;
258 	cxld->hpa_range = (struct range) {
259 		.start = res->start,
260 		.end = res->end,
261 	};
262 	cxld->interleave_ways = ways;
263 	/*
264 	 * Minimize the x1 granularity to advertise support for any
265 	 * valid region granularity
266 	 */
267 	if (ways == 1)
268 		ig = CXL_DECODER_MIN_GRANULARITY;
269 	cxld->interleave_granularity = ig;
270 
271 	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
272 		if (ways != 1 && ways != 3) {
273 			cxims_ctx = (struct cxl_cxims_context) {
274 				.dev = dev,
275 				.cxlrd = cxlrd,
276 			};
277 			rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS,
278 						   cxl_parse_cxims, &cxims_ctx);
279 			if (rc < 0)
280 				goto err_xormap;
281 			if (!cxlrd->platform_data) {
282 				dev_err(dev, "No CXIMS for HBIG %u\n", ig);
283 				rc = -EINVAL;
284 				goto err_xormap;
285 			}
286 		}
287 	}
288 	rc = cxl_decoder_add(cxld, target_map);
289 err_xormap:
290 	if (rc)
291 		put_device(&cxld->dev);
292 	else
293 		rc = cxl_decoder_autoremove(dev, cxld);
294 	return rc;
295 
296 err_insert:
297 	kfree(res->name);
298 err_name:
299 	kfree(res);
300 	return -ENOMEM;
301 }
302 
303 static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
304 			   const unsigned long end)
305 {
306 	struct acpi_cedt_cfmws *cfmws = (struct acpi_cedt_cfmws *)header;
307 	struct cxl_cfmws_context *ctx = arg;
308 	struct device *dev = ctx->dev;
309 	int rc;
310 
311 	rc = __cxl_parse_cfmws(cfmws, ctx);
312 	if (rc)
313 		dev_err(dev,
314 			"Failed to add decode range: [%#llx - %#llx] (%d)\n",
315 			cfmws->base_hpa,
316 			cfmws->base_hpa + cfmws->window_size - 1, rc);
317 	else
318 		dev_dbg(dev, "decode range: node: %d range [%#llx - %#llx]\n",
319 			phys_to_target_node(cfmws->base_hpa), cfmws->base_hpa,
320 			cfmws->base_hpa + cfmws->window_size - 1);
321 
322 	/* never fail cxl_acpi load for a single window failure */
323 	return 0;
324 }
325 
326 __mock struct acpi_device *to_cxl_host_bridge(struct device *host,
327 					      struct device *dev)
328 {
329 	struct acpi_device *adev = to_acpi_device(dev);
330 
331 	if (!acpi_pci_find_root(adev->handle))
332 		return NULL;
333 
334 	if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0)
335 		return adev;
336 	return NULL;
337 }
338 
339 /* Note, @dev is used by mock_acpi_table_parse_cedt() */
340 struct cxl_chbs_context {
341 	struct device *dev;
342 	unsigned long long uid;
343 	resource_size_t base;
344 	u32 cxl_version;
345 };
346 
347 static int cxl_get_chbs_iter(union acpi_subtable_headers *header, void *arg,
348 			     const unsigned long end)
349 {
350 	struct cxl_chbs_context *ctx = arg;
351 	struct acpi_cedt_chbs *chbs;
352 
353 	if (ctx->base != CXL_RESOURCE_NONE)
354 		return 0;
355 
356 	chbs = (struct acpi_cedt_chbs *) header;
357 
358 	if (ctx->uid != chbs->uid)
359 		return 0;
360 
361 	ctx->cxl_version = chbs->cxl_version;
362 	if (!chbs->base)
363 		return 0;
364 
365 	if (chbs->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11 &&
366 	    chbs->length != CXL_RCRB_SIZE)
367 		return 0;
368 
369 	ctx->base = chbs->base;
370 
371 	return 0;
372 }
373 
374 static int cxl_get_chbs(struct device *dev, struct acpi_device *hb,
375 			struct cxl_chbs_context *ctx)
376 {
377 	unsigned long long uid;
378 	int rc;
379 
380 	rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid);
381 	if (rc != AE_OK) {
382 		dev_err(dev, "unable to retrieve _UID\n");
383 		return -ENOENT;
384 	}
385 
386 	dev_dbg(dev, "UID found: %lld\n", uid);
387 	*ctx = (struct cxl_chbs_context) {
388 		.dev = dev,
389 		.uid = uid,
390 		.base = CXL_RESOURCE_NONE,
391 		.cxl_version = UINT_MAX,
392 	};
393 
394 	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbs_iter, ctx);
395 
396 	return 0;
397 }
398 
399 static int add_host_bridge_dport(struct device *match, void *arg)
400 {
401 	acpi_status rc;
402 	struct device *bridge;
403 	struct cxl_dport *dport;
404 	struct cxl_chbs_context ctx;
405 	struct acpi_pci_root *pci_root;
406 	struct cxl_port *root_port = arg;
407 	struct device *host = root_port->dev.parent;
408 	struct acpi_device *hb = to_cxl_host_bridge(host, match);
409 
410 	if (!hb)
411 		return 0;
412 
413 	rc = cxl_get_chbs(match, hb, &ctx);
414 	if (rc)
415 		return rc;
416 
417 	if (ctx.cxl_version == UINT_MAX) {
418 		dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
419 			 ctx.uid);
420 		return 0;
421 	}
422 
423 	if (ctx.base == CXL_RESOURCE_NONE) {
424 		dev_warn(match, "CHBS invalid for Host Bridge (UID %lld)\n",
425 			 ctx.uid);
426 		return 0;
427 	}
428 
429 	pci_root = acpi_pci_find_root(hb->handle);
430 	bridge = pci_root->bus->bridge;
431 
432 	/*
433 	 * In RCH mode, bind the component regs base to the dport. In
434 	 * VH mode it will be bound to the CXL host bridge's port
435 	 * object later in add_host_bridge_uport().
436 	 */
437 	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
438 		dev_dbg(match, "RCRB found for UID %lld: %pa\n", ctx.uid,
439 			&ctx.base);
440 		dport = devm_cxl_add_rch_dport(root_port, bridge, ctx.uid,
441 					       ctx.base);
442 	} else {
443 		dport = devm_cxl_add_dport(root_port, bridge, ctx.uid,
444 					   CXL_RESOURCE_NONE);
445 	}
446 
447 	if (IS_ERR(dport))
448 		return PTR_ERR(dport);
449 
450 	return 0;
451 }
452 
453 /*
454  * A host bridge is a dport to a CFMWS decode and it is a uport to the
455  * dport (PCIe Root Ports) in the host bridge.
456  */
457 static int add_host_bridge_uport(struct device *match, void *arg)
458 {
459 	struct cxl_port *root_port = arg;
460 	struct device *host = root_port->dev.parent;
461 	struct acpi_device *hb = to_cxl_host_bridge(host, match);
462 	struct acpi_pci_root *pci_root;
463 	struct cxl_dport *dport;
464 	struct cxl_port *port;
465 	struct device *bridge;
466 	struct cxl_chbs_context ctx;
467 	resource_size_t component_reg_phys;
468 	int rc;
469 
470 	if (!hb)
471 		return 0;
472 
473 	pci_root = acpi_pci_find_root(hb->handle);
474 	bridge = pci_root->bus->bridge;
475 	dport = cxl_find_dport_by_dev(root_port, bridge);
476 	if (!dport) {
477 		dev_dbg(host, "host bridge expected and not found\n");
478 		return 0;
479 	}
480 
481 	if (dport->rch) {
482 		dev_info(bridge, "host supports CXL (restricted)\n");
483 		return 0;
484 	}
485 
486 	rc = cxl_get_chbs(match, hb, &ctx);
487 	if (rc)
488 		return rc;
489 
490 	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
491 		dev_warn(bridge,
492 			 "CXL CHBS version mismatch, skip port registration\n");
493 		return 0;
494 	}
495 
496 	component_reg_phys = ctx.base;
497 	if (component_reg_phys != CXL_RESOURCE_NONE)
498 		dev_dbg(match, "CHBCR found for UID %lld: %pa\n",
499 			ctx.uid, &component_reg_phys);
500 
501 	rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus);
502 	if (rc)
503 		return rc;
504 
505 	port = devm_cxl_add_port(host, bridge, component_reg_phys, dport);
506 	if (IS_ERR(port))
507 		return PTR_ERR(port);
508 
509 	dev_info(bridge, "host supports CXL\n");
510 
511 	return 0;
512 }
513 
514 static int add_root_nvdimm_bridge(struct device *match, void *data)
515 {
516 	struct cxl_decoder *cxld;
517 	struct cxl_port *root_port = data;
518 	struct cxl_nvdimm_bridge *cxl_nvb;
519 	struct device *host = root_port->dev.parent;
520 
521 	if (!is_root_decoder(match))
522 		return 0;
523 
524 	cxld = to_cxl_decoder(match);
525 	if (!(cxld->flags & CXL_DECODER_F_PMEM))
526 		return 0;
527 
528 	cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port);
529 	if (IS_ERR(cxl_nvb)) {
530 		dev_dbg(host, "failed to register pmem\n");
531 		return PTR_ERR(cxl_nvb);
532 	}
533 	dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev),
534 		dev_name(&cxl_nvb->dev));
535 	return 1;
536 }
537 
538 static struct lock_class_key cxl_root_key;
539 
540 static void cxl_acpi_lock_reset_class(void *dev)
541 {
542 	device_lock_reset_class(dev);
543 }
544 
545 static void del_cxl_resource(struct resource *res)
546 {
547 	kfree(res->name);
548 	kfree(res);
549 }
550 
551 static void cxl_set_public_resource(struct resource *priv, struct resource *pub)
552 {
553 	priv->desc = (unsigned long) pub;
554 }
555 
556 static struct resource *cxl_get_public_resource(struct resource *priv)
557 {
558 	return (struct resource *) priv->desc;
559 }
560 
561 static void remove_cxl_resources(void *data)
562 {
563 	struct resource *res, *next, *cxl = data;
564 
565 	for (res = cxl->child; res; res = next) {
566 		struct resource *victim = cxl_get_public_resource(res);
567 
568 		next = res->sibling;
569 		remove_resource(res);
570 
571 		if (victim) {
572 			remove_resource(victim);
573 			kfree(victim);
574 		}
575 
576 		del_cxl_resource(res);
577 	}
578 }
579 
580 /**
581  * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource
582  * @cxl_res: A standalone resource tree where each CXL window is a sibling
583  *
584  * Walk each CXL window in @cxl_res and add it to iomem_resource potentially
585  * expanding its boundaries to ensure that any conflicting resources become
586  * children. If a window is expanded it may then conflict with a another window
587  * entry and require the window to be truncated or trimmed. Consider this
588  * situation:
589  *
590  * |-- "CXL Window 0" --||----- "CXL Window 1" -----|
591  * |--------------- "System RAM" -------------|
592  *
593  * ...where platform firmware has established as System RAM resource across 2
594  * windows, but has left some portion of window 1 for dynamic CXL region
595  * provisioning. In this case "Window 0" will span the entirety of the "System
596  * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end
597  * of that "System RAM" resource.
598  */
599 static int add_cxl_resources(struct resource *cxl_res)
600 {
601 	struct resource *res, *new, *next;
602 
603 	for (res = cxl_res->child; res; res = next) {
604 		new = kzalloc(sizeof(*new), GFP_KERNEL);
605 		if (!new)
606 			return -ENOMEM;
607 		new->name = res->name;
608 		new->start = res->start;
609 		new->end = res->end;
610 		new->flags = IORESOURCE_MEM;
611 		new->desc = IORES_DESC_CXL;
612 
613 		/*
614 		 * Record the public resource in the private cxl_res tree for
615 		 * later removal.
616 		 */
617 		cxl_set_public_resource(res, new);
618 
619 		insert_resource_expand_to_fit(&iomem_resource, new);
620 
621 		next = res->sibling;
622 		while (next && resource_overlaps(new, next)) {
623 			if (resource_contains(new, next)) {
624 				struct resource *_next = next->sibling;
625 
626 				remove_resource(next);
627 				del_cxl_resource(next);
628 				next = _next;
629 			} else
630 				next->start = new->end + 1;
631 		}
632 	}
633 	return 0;
634 }
635 
636 static int pair_cxl_resource(struct device *dev, void *data)
637 {
638 	struct resource *cxl_res = data;
639 	struct resource *p;
640 
641 	if (!is_root_decoder(dev))
642 		return 0;
643 
644 	for (p = cxl_res->child; p; p = p->sibling) {
645 		struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
646 		struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
647 		struct resource res = {
648 			.start = cxld->hpa_range.start,
649 			.end = cxld->hpa_range.end,
650 			.flags = IORESOURCE_MEM,
651 		};
652 
653 		if (resource_contains(p, &res)) {
654 			cxlrd->res = cxl_get_public_resource(p);
655 			break;
656 		}
657 	}
658 
659 	return 0;
660 }
661 
662 static int cxl_acpi_probe(struct platform_device *pdev)
663 {
664 	int rc;
665 	struct resource *cxl_res;
666 	struct cxl_port *root_port;
667 	struct device *host = &pdev->dev;
668 	struct acpi_device *adev = ACPI_COMPANION(host);
669 	struct cxl_cfmws_context ctx;
670 
671 	device_lock_set_class(&pdev->dev, &cxl_root_key);
672 	rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class,
673 				      &pdev->dev);
674 	if (rc)
675 		return rc;
676 
677 	cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL);
678 	if (!cxl_res)
679 		return -ENOMEM;
680 	cxl_res->name = "CXL mem";
681 	cxl_res->start = 0;
682 	cxl_res->end = -1;
683 	cxl_res->flags = IORESOURCE_MEM;
684 
685 	root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);
686 	if (IS_ERR(root_port))
687 		return PTR_ERR(root_port);
688 
689 	rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
690 			      add_host_bridge_dport);
691 	if (rc < 0)
692 		return rc;
693 
694 	rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res);
695 	if (rc)
696 		return rc;
697 
698 	ctx = (struct cxl_cfmws_context) {
699 		.dev = host,
700 		.root_port = root_port,
701 		.cxl_res = cxl_res,
702 	};
703 	rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx);
704 	if (rc < 0)
705 		return -ENXIO;
706 
707 	rc = add_cxl_resources(cxl_res);
708 	if (rc)
709 		return rc;
710 
711 	/*
712 	 * Populate the root decoders with their related iomem resource,
713 	 * if present
714 	 */
715 	device_for_each_child(&root_port->dev, cxl_res, pair_cxl_resource);
716 
717 	/*
718 	 * Root level scanned with host-bridge as dports, now scan host-bridges
719 	 * for their role as CXL uports to their CXL-capable PCIe Root Ports.
720 	 */
721 	rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
722 			      add_host_bridge_uport);
723 	if (rc < 0)
724 		return rc;
725 
726 	if (IS_ENABLED(CONFIG_CXL_PMEM))
727 		rc = device_for_each_child(&root_port->dev, root_port,
728 					   add_root_nvdimm_bridge);
729 	if (rc < 0)
730 		return rc;
731 
732 	/* In case PCI is scanned before ACPI re-trigger memdev attach */
733 	cxl_bus_rescan();
734 	return 0;
735 }
736 
737 static const struct acpi_device_id cxl_acpi_ids[] = {
738 	{ "ACPI0017" },
739 	{ },
740 };
741 MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids);
742 
743 static const struct platform_device_id cxl_test_ids[] = {
744 	{ "cxl_acpi" },
745 	{ },
746 };
747 MODULE_DEVICE_TABLE(platform, cxl_test_ids);
748 
749 static struct platform_driver cxl_acpi_driver = {
750 	.probe = cxl_acpi_probe,
751 	.driver = {
752 		.name = KBUILD_MODNAME,
753 		.acpi_match_table = cxl_acpi_ids,
754 	},
755 	.id_table = cxl_test_ids,
756 };
757 
758 static int __init cxl_acpi_init(void)
759 {
760 	return platform_driver_register(&cxl_acpi_driver);
761 }
762 
763 static void __exit cxl_acpi_exit(void)
764 {
765 	platform_driver_unregister(&cxl_acpi_driver);
766 	cxl_bus_drain();
767 }
768 
769 /* load before dax_hmem sees 'Soft Reserved' CXL ranges */
770 subsys_initcall(cxl_acpi_init);
771 module_exit(cxl_acpi_exit);
772 MODULE_LICENSE("GPL v2");
773 MODULE_IMPORT_NS(CXL);
774 MODULE_IMPORT_NS(ACPI);
775