Linux Audio

Check our new training course

Loading...
Note: File does not exist in v5.9.
  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
 15struct cxl_cxims_data {
 16	int nr_maps;
 17	u64 xormaps[];
 18};
 19
 20/*
 21 * Find a targets entry (n) in the host bridge interleave list.
 22 * CXL Specfication 3.0 Table 9-22
 23 */
 24static 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
 45static 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
 72struct cxl_cxims_context {
 73	struct device *dev;
 74	struct cxl_root_decoder *cxlrd;
 75};
 76
 77static 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	memcpy(cximsd->xormaps, cxims->xormap_list,
116	       nr_maps * sizeof(*cximsd->xormaps));
117	cximsd->nr_maps = nr_maps;
118	cxlrd->platform_data = cximsd;
119
120	return 0;
121}
122
123static 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
141static 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 */
190struct cxl_cfmws_context {
191	struct device *dev;
192	struct cxl_port *root_port;
193	struct resource *cxl_res;
194	int id;
195};
196
197static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
198			   const unsigned long end)
199{
200	int target_map[CXL_DECODER_MAX_INTERLEAVE];
201	struct cxl_cfmws_context *ctx = arg;
202	struct cxl_port *root_port = ctx->root_port;
203	struct resource *cxl_res = ctx->cxl_res;
204	struct cxl_cxims_context cxims_ctx;
205	struct cxl_root_decoder *cxlrd;
206	struct device *dev = ctx->dev;
207	struct acpi_cedt_cfmws *cfmws;
208	cxl_calc_hb_fn cxl_calc_hb;
209	struct cxl_decoder *cxld;
210	unsigned int ways, i, ig;
211	struct resource *res;
212	int rc;
213
214	cfmws = (struct acpi_cedt_cfmws *) header;
215
216	rc = cxl_acpi_cfmws_verify(dev, cfmws);
217	if (rc) {
218		dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
219			cfmws->base_hpa,
220			cfmws->base_hpa + cfmws->window_size - 1);
221		return 0;
222	}
223
224	rc = eiw_to_ways(cfmws->interleave_ways, &ways);
225	if (rc)
226		return rc;
227	rc = eig_to_granularity(cfmws->granularity, &ig);
228	if (rc)
229		return rc;
230	for (i = 0; i < ways; i++)
231		target_map[i] = cfmws->interleave_targets[i];
232
233	res = kzalloc(sizeof(*res), GFP_KERNEL);
234	if (!res)
235		return -ENOMEM;
236
237	res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++);
238	if (!res->name)
239		goto err_name;
240
241	res->start = cfmws->base_hpa;
242	res->end = cfmws->base_hpa + cfmws->window_size - 1;
243	res->flags = IORESOURCE_MEM;
244
245	/* add to the local resource tracking to establish a sort order */
246	rc = insert_resource(cxl_res, res);
247	if (rc)
248		goto err_insert;
249
250	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO)
251		cxl_calc_hb = cxl_hb_modulo;
252	else
253		cxl_calc_hb = cxl_hb_xor;
254
255	cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
256	if (IS_ERR(cxlrd))
257		return 0;
258
259	cxld = &cxlrd->cxlsd.cxld;
260	cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
261	cxld->target_type = CXL_DECODER_EXPANDER;
262	cxld->hpa_range = (struct range) {
263		.start = res->start,
264		.end = res->end,
265	};
266	cxld->interleave_ways = ways;
267	/*
268	 * Minimize the x1 granularity to advertise support for any
269	 * valid region granularity
270	 */
271	if (ways == 1)
272		ig = CXL_DECODER_MIN_GRANULARITY;
273	cxld->interleave_granularity = ig;
274
275	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
276		if (ways != 1 && ways != 3) {
277			cxims_ctx = (struct cxl_cxims_context) {
278				.dev = dev,
279				.cxlrd = cxlrd,
280			};
281			rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS,
282						   cxl_parse_cxims, &cxims_ctx);
283			if (rc < 0)
284				goto err_xormap;
285			if (!cxlrd->platform_data) {
286				dev_err(dev, "No CXIMS for HBIG %u\n", ig);
287				rc = -EINVAL;
288				goto err_xormap;
289			}
290		}
291	}
292	rc = cxl_decoder_add(cxld, target_map);
293err_xormap:
294	if (rc)
295		put_device(&cxld->dev);
296	else
297		rc = cxl_decoder_autoremove(dev, cxld);
298	if (rc) {
299		dev_err(dev, "Failed to add decode range [%#llx - %#llx]\n",
300			cxld->hpa_range.start, cxld->hpa_range.end);
301		return 0;
302	}
303	dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n",
304		dev_name(&cxld->dev),
305		phys_to_target_node(cxld->hpa_range.start),
306		cxld->hpa_range.start, cxld->hpa_range.end);
307
308	return 0;
309
310err_insert:
311	kfree(res->name);
312err_name:
313	kfree(res);
314	return -ENOMEM;
315}
316
317__mock struct acpi_device *to_cxl_host_bridge(struct device *host,
318					      struct device *dev)
319{
320	struct acpi_device *adev = to_acpi_device(dev);
321
322	if (!acpi_pci_find_root(adev->handle))
323		return NULL;
324
325	if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0)
326		return adev;
327	return NULL;
328}
329
330/*
331 * A host bridge is a dport to a CFMWS decode and it is a uport to the
332 * dport (PCIe Root Ports) in the host bridge.
333 */
334static int add_host_bridge_uport(struct device *match, void *arg)
335{
336	struct cxl_port *root_port = arg;
337	struct device *host = root_port->dev.parent;
338	struct acpi_device *hb = to_cxl_host_bridge(host, match);
339	struct acpi_pci_root *pci_root;
340	struct cxl_dport *dport;
341	struct cxl_port *port;
342	struct device *bridge;
343	int rc;
344
345	if (!hb)
346		return 0;
347
348	pci_root = acpi_pci_find_root(hb->handle);
349	bridge = pci_root->bus->bridge;
350	dport = cxl_find_dport_by_dev(root_port, bridge);
351	if (!dport) {
352		dev_dbg(host, "host bridge expected and not found\n");
353		return 0;
354	}
355
356	if (dport->rch) {
357		dev_info(bridge, "host supports CXL (restricted)\n");
358		return 0;
359	}
360
361	rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus);
362	if (rc)
363		return rc;
364
365	port = devm_cxl_add_port(host, bridge, dport->component_reg_phys,
366				 dport);
367	if (IS_ERR(port))
368		return PTR_ERR(port);
369
370	dev_info(bridge, "host supports CXL\n");
371
372	return 0;
373}
374
375struct cxl_chbs_context {
376	struct device *dev;
377	unsigned long long uid;
378	resource_size_t rcrb;
379	resource_size_t chbcr;
380	u32 cxl_version;
381};
382
383static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
384			 const unsigned long end)
385{
386	struct cxl_chbs_context *ctx = arg;
387	struct acpi_cedt_chbs *chbs;
388
389	if (ctx->chbcr)
390		return 0;
391
392	chbs = (struct acpi_cedt_chbs *) header;
393
394	if (ctx->uid != chbs->uid)
395		return 0;
396
397	ctx->cxl_version = chbs->cxl_version;
398	ctx->rcrb = CXL_RESOURCE_NONE;
399	ctx->chbcr = CXL_RESOURCE_NONE;
400
401	if (!chbs->base)
402		return 0;
403
404	if (chbs->cxl_version != ACPI_CEDT_CHBS_VERSION_CXL11) {
405		ctx->chbcr = chbs->base;
406		return 0;
407	}
408
409	if (chbs->length != CXL_RCRB_SIZE)
410		return 0;
411
412	ctx->rcrb = chbs->base;
413	ctx->chbcr = cxl_rcrb_to_component(ctx->dev, chbs->base,
414					   CXL_RCRB_DOWNSTREAM);
415
416	return 0;
417}
418
419static int add_host_bridge_dport(struct device *match, void *arg)
420{
421	acpi_status rc;
422	struct device *bridge;
423	unsigned long long uid;
424	struct cxl_dport *dport;
425	struct cxl_chbs_context ctx;
426	struct acpi_pci_root *pci_root;
427	struct cxl_port *root_port = arg;
428	struct device *host = root_port->dev.parent;
429	struct acpi_device *hb = to_cxl_host_bridge(host, match);
430
431	if (!hb)
432		return 0;
433
434	rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid);
435	if (rc != AE_OK) {
436		dev_err(match, "unable to retrieve _UID\n");
437		return -ENODEV;
438	}
439
440	dev_dbg(match, "UID found: %lld\n", uid);
441
442	ctx = (struct cxl_chbs_context) {
443		.dev = match,
444		.uid = uid,
445	};
446	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx);
447
448	if (!ctx.chbcr) {
449		dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
450			 uid);
451		return 0;
452	}
453
454	if (ctx.rcrb != CXL_RESOURCE_NONE)
455		dev_dbg(match, "RCRB found for UID %lld: %pa\n", uid, &ctx.rcrb);
456
457	if (ctx.chbcr == CXL_RESOURCE_NONE) {
458		dev_warn(match, "CHBCR invalid for Host Bridge (UID %lld)\n",
459			 uid);
460		return 0;
461	}
462
463	dev_dbg(match, "CHBCR found: %pa\n", &ctx.chbcr);
464
465	pci_root = acpi_pci_find_root(hb->handle);
466	bridge = pci_root->bus->bridge;
467	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11)
468		dport = devm_cxl_add_rch_dport(root_port, bridge, uid,
469					       ctx.chbcr, ctx.rcrb);
470	else
471		dport = devm_cxl_add_dport(root_port, bridge, uid,
472					   ctx.chbcr);
473	if (IS_ERR(dport))
474		return PTR_ERR(dport);
475
476	return 0;
477}
478
479static int add_root_nvdimm_bridge(struct device *match, void *data)
480{
481	struct cxl_decoder *cxld;
482	struct cxl_port *root_port = data;
483	struct cxl_nvdimm_bridge *cxl_nvb;
484	struct device *host = root_port->dev.parent;
485
486	if (!is_root_decoder(match))
487		return 0;
488
489	cxld = to_cxl_decoder(match);
490	if (!(cxld->flags & CXL_DECODER_F_PMEM))
491		return 0;
492
493	cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port);
494	if (IS_ERR(cxl_nvb)) {
495		dev_dbg(host, "failed to register pmem\n");
496		return PTR_ERR(cxl_nvb);
497	}
498	dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev),
499		dev_name(&cxl_nvb->dev));
500	return 1;
501}
502
503static struct lock_class_key cxl_root_key;
504
505static void cxl_acpi_lock_reset_class(void *dev)
506{
507	device_lock_reset_class(dev);
508}
509
510static void del_cxl_resource(struct resource *res)
511{
512	kfree(res->name);
513	kfree(res);
514}
515
516static void cxl_set_public_resource(struct resource *priv, struct resource *pub)
517{
518	priv->desc = (unsigned long) pub;
519}
520
521static struct resource *cxl_get_public_resource(struct resource *priv)
522{
523	return (struct resource *) priv->desc;
524}
525
526static void remove_cxl_resources(void *data)
527{
528	struct resource *res, *next, *cxl = data;
529
530	for (res = cxl->child; res; res = next) {
531		struct resource *victim = cxl_get_public_resource(res);
532
533		next = res->sibling;
534		remove_resource(res);
535
536		if (victim) {
537			remove_resource(victim);
538			kfree(victim);
539		}
540
541		del_cxl_resource(res);
542	}
543}
544
545/**
546 * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource
547 * @cxl_res: A standalone resource tree where each CXL window is a sibling
548 *
549 * Walk each CXL window in @cxl_res and add it to iomem_resource potentially
550 * expanding its boundaries to ensure that any conflicting resources become
551 * children. If a window is expanded it may then conflict with a another window
552 * entry and require the window to be truncated or trimmed. Consider this
553 * situation:
554 *
555 * |-- "CXL Window 0" --||----- "CXL Window 1" -----|
556 * |--------------- "System RAM" -------------|
557 *
558 * ...where platform firmware has established as System RAM resource across 2
559 * windows, but has left some portion of window 1 for dynamic CXL region
560 * provisioning. In this case "Window 0" will span the entirety of the "System
561 * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end
562 * of that "System RAM" resource.
563 */
564static int add_cxl_resources(struct resource *cxl_res)
565{
566	struct resource *res, *new, *next;
567
568	for (res = cxl_res->child; res; res = next) {
569		new = kzalloc(sizeof(*new), GFP_KERNEL);
570		if (!new)
571			return -ENOMEM;
572		new->name = res->name;
573		new->start = res->start;
574		new->end = res->end;
575		new->flags = IORESOURCE_MEM;
576		new->desc = IORES_DESC_CXL;
577
578		/*
579		 * Record the public resource in the private cxl_res tree for
580		 * later removal.
581		 */
582		cxl_set_public_resource(res, new);
583
584		insert_resource_expand_to_fit(&iomem_resource, new);
585
586		next = res->sibling;
587		while (next && resource_overlaps(new, next)) {
588			if (resource_contains(new, next)) {
589				struct resource *_next = next->sibling;
590
591				remove_resource(next);
592				del_cxl_resource(next);
593				next = _next;
594			} else
595				next->start = new->end + 1;
596		}
597	}
598	return 0;
599}
600
601static int pair_cxl_resource(struct device *dev, void *data)
602{
603	struct resource *cxl_res = data;
604	struct resource *p;
605
606	if (!is_root_decoder(dev))
607		return 0;
608
609	for (p = cxl_res->child; p; p = p->sibling) {
610		struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
611		struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
612		struct resource res = {
613			.start = cxld->hpa_range.start,
614			.end = cxld->hpa_range.end,
615			.flags = IORESOURCE_MEM,
616		};
617
618		if (resource_contains(p, &res)) {
619			cxlrd->res = cxl_get_public_resource(p);
620			break;
621		}
622	}
623
624	return 0;
625}
626
627static int cxl_acpi_probe(struct platform_device *pdev)
628{
629	int rc;
630	struct resource *cxl_res;
631	struct cxl_port *root_port;
632	struct device *host = &pdev->dev;
633	struct acpi_device *adev = ACPI_COMPANION(host);
634	struct cxl_cfmws_context ctx;
635
636	device_lock_set_class(&pdev->dev, &cxl_root_key);
637	rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class,
638				      &pdev->dev);
639	if (rc)
640		return rc;
641
642	cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL);
643	if (!cxl_res)
644		return -ENOMEM;
645	cxl_res->name = "CXL mem";
646	cxl_res->start = 0;
647	cxl_res->end = -1;
648	cxl_res->flags = IORESOURCE_MEM;
649
650	root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);
651	if (IS_ERR(root_port))
652		return PTR_ERR(root_port);
653
654	rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
655			      add_host_bridge_dport);
656	if (rc < 0)
657		return rc;
658
659	rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res);
660	if (rc)
661		return rc;
662
663	ctx = (struct cxl_cfmws_context) {
664		.dev = host,
665		.root_port = root_port,
666		.cxl_res = cxl_res,
667	};
668	rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx);
669	if (rc < 0)
670		return -ENXIO;
671
672	rc = add_cxl_resources(cxl_res);
673	if (rc)
674		return rc;
675
676	/*
677	 * Populate the root decoders with their related iomem resource,
678	 * if present
679	 */
680	device_for_each_child(&root_port->dev, cxl_res, pair_cxl_resource);
681
682	/*
683	 * Root level scanned with host-bridge as dports, now scan host-bridges
684	 * for their role as CXL uports to their CXL-capable PCIe Root Ports.
685	 */
686	rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
687			      add_host_bridge_uport);
688	if (rc < 0)
689		return rc;
690
691	if (IS_ENABLED(CONFIG_CXL_PMEM))
692		rc = device_for_each_child(&root_port->dev, root_port,
693					   add_root_nvdimm_bridge);
694	if (rc < 0)
695		return rc;
696
697	/* In case PCI is scanned before ACPI re-trigger memdev attach */
698	cxl_bus_rescan();
699	return 0;
700}
701
702static const struct acpi_device_id cxl_acpi_ids[] = {
703	{ "ACPI0017" },
704	{ },
705};
706MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids);
707
708static const struct platform_device_id cxl_test_ids[] = {
709	{ "cxl_acpi" },
710	{ },
711};
712MODULE_DEVICE_TABLE(platform, cxl_test_ids);
713
714static struct platform_driver cxl_acpi_driver = {
715	.probe = cxl_acpi_probe,
716	.driver = {
717		.name = KBUILD_MODNAME,
718		.acpi_match_table = cxl_acpi_ids,
719	},
720	.id_table = cxl_test_ids,
721};
722
723static int __init cxl_acpi_init(void)
724{
725	return platform_driver_register(&cxl_acpi_driver);
726}
727
728static void __exit cxl_acpi_exit(void)
729{
730	platform_driver_unregister(&cxl_acpi_driver);
731	cxl_bus_drain();
732}
733
734module_init(cxl_acpi_init);
735module_exit(cxl_acpi_exit);
736MODULE_LICENSE("GPL v2");
737MODULE_IMPORT_NS(CXL);
738MODULE_IMPORT_NS(ACPI);