xref: /openbmc/linux/drivers/acpi/nfit/core.c (revision 3a0e75ad)
1 /*
2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  */
13 #include <linux/list_sort.h>
14 #include <linux/libnvdimm.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/ndctl.h>
18 #include <linux/sysfs.h>
19 #include <linux/delay.h>
20 #include <linux/list.h>
21 #include <linux/acpi.h>
22 #include <linux/sort.h>
23 #include <linux/pmem.h>
24 #include <linux/io.h>
25 #include <linux/nd.h>
26 #include <asm/cacheflush.h>
27 #include "nfit.h"
28 
29 /*
30  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
31  * irrelevant.
32  */
33 #include <linux/io-64-nonatomic-hi-lo.h>
34 
35 static bool force_enable_dimms;
36 module_param(force_enable_dimms, bool, S_IRUGO|S_IWUSR);
37 MODULE_PARM_DESC(force_enable_dimms, "Ignore _STA (ACPI DIMM device) status");
38 
39 static unsigned int scrub_timeout = NFIT_ARS_TIMEOUT;
40 module_param(scrub_timeout, uint, S_IRUGO|S_IWUSR);
41 MODULE_PARM_DESC(scrub_timeout, "Initial scrub timeout in seconds");
42 
43 /* after three payloads of overflow, it's dead jim */
44 static unsigned int scrub_overflow_abort = 3;
45 module_param(scrub_overflow_abort, uint, S_IRUGO|S_IWUSR);
46 MODULE_PARM_DESC(scrub_overflow_abort,
47 		"Number of times we overflow ARS results before abort");
48 
49 static bool disable_vendor_specific;
50 module_param(disable_vendor_specific, bool, S_IRUGO);
51 MODULE_PARM_DESC(disable_vendor_specific,
52 		"Limit commands to the publicly specified set\n");
53 
54 LIST_HEAD(acpi_descs);
55 DEFINE_MUTEX(acpi_desc_lock);
56 
57 static struct workqueue_struct *nfit_wq;
58 
59 struct nfit_table_prev {
60 	struct list_head spas;
61 	struct list_head memdevs;
62 	struct list_head dcrs;
63 	struct list_head bdws;
64 	struct list_head idts;
65 	struct list_head flushes;
66 };
67 
68 static u8 nfit_uuid[NFIT_UUID_MAX][16];
69 
70 const u8 *to_nfit_uuid(enum nfit_uuids id)
71 {
72 	return nfit_uuid[id];
73 }
74 EXPORT_SYMBOL(to_nfit_uuid);
75 
76 static struct acpi_nfit_desc *to_acpi_nfit_desc(
77 		struct nvdimm_bus_descriptor *nd_desc)
78 {
79 	return container_of(nd_desc, struct acpi_nfit_desc, nd_desc);
80 }
81 
82 static struct acpi_device *to_acpi_dev(struct acpi_nfit_desc *acpi_desc)
83 {
84 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
85 
86 	/*
87 	 * If provider == 'ACPI.NFIT' we can assume 'dev' is a struct
88 	 * acpi_device.
89 	 */
90 	if (!nd_desc->provider_name
91 			|| strcmp(nd_desc->provider_name, "ACPI.NFIT") != 0)
92 		return NULL;
93 
94 	return to_acpi_device(acpi_desc->dev);
95 }
96 
97 static int xlat_bus_status(void *buf, unsigned int cmd, u32 status)
98 {
99 	struct nd_cmd_clear_error *clear_err;
100 	struct nd_cmd_ars_status *ars_status;
101 	u16 flags;
102 
103 	switch (cmd) {
104 	case ND_CMD_ARS_CAP:
105 		if ((status & 0xffff) == NFIT_ARS_CAP_NONE)
106 			return -ENOTTY;
107 
108 		/* Command failed */
109 		if (status & 0xffff)
110 			return -EIO;
111 
112 		/* No supported scan types for this range */
113 		flags = ND_ARS_PERSISTENT | ND_ARS_VOLATILE;
114 		if ((status >> 16 & flags) == 0)
115 			return -ENOTTY;
116 		return 0;
117 	case ND_CMD_ARS_START:
118 		/* ARS is in progress */
119 		if ((status & 0xffff) == NFIT_ARS_START_BUSY)
120 			return -EBUSY;
121 
122 		/* Command failed */
123 		if (status & 0xffff)
124 			return -EIO;
125 		return 0;
126 	case ND_CMD_ARS_STATUS:
127 		ars_status = buf;
128 		/* Command failed */
129 		if (status & 0xffff)
130 			return -EIO;
131 		/* Check extended status (Upper two bytes) */
132 		if (status == NFIT_ARS_STATUS_DONE)
133 			return 0;
134 
135 		/* ARS is in progress */
136 		if (status == NFIT_ARS_STATUS_BUSY)
137 			return -EBUSY;
138 
139 		/* No ARS performed for the current boot */
140 		if (status == NFIT_ARS_STATUS_NONE)
141 			return -EAGAIN;
142 
143 		/*
144 		 * ARS interrupted, either we overflowed or some other
145 		 * agent wants the scan to stop.  If we didn't overflow
146 		 * then just continue with the returned results.
147 		 */
148 		if (status == NFIT_ARS_STATUS_INTR) {
149 			if (ars_status->out_length >= 40 && (ars_status->flags
150 						& NFIT_ARS_F_OVERFLOW))
151 				return -ENOSPC;
152 			return 0;
153 		}
154 
155 		/* Unknown status */
156 		if (status >> 16)
157 			return -EIO;
158 		return 0;
159 	case ND_CMD_CLEAR_ERROR:
160 		clear_err = buf;
161 		if (status & 0xffff)
162 			return -EIO;
163 		if (!clear_err->cleared)
164 			return -EIO;
165 		if (clear_err->length > clear_err->cleared)
166 			return clear_err->cleared;
167 		return 0;
168 	default:
169 		break;
170 	}
171 
172 	/* all other non-zero status results in an error */
173 	if (status)
174 		return -EIO;
175 	return 0;
176 }
177 
178 static int xlat_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd,
179 		u32 status)
180 {
181 	if (!nvdimm)
182 		return xlat_bus_status(buf, cmd, status);
183 	if (status)
184 		return -EIO;
185 	return 0;
186 }
187 
188 int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
189 		unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
190 {
191 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
192 	union acpi_object in_obj, in_buf, *out_obj;
193 	const struct nd_cmd_desc *desc = NULL;
194 	struct device *dev = acpi_desc->dev;
195 	struct nd_cmd_pkg *call_pkg = NULL;
196 	const char *cmd_name, *dimm_name;
197 	unsigned long cmd_mask, dsm_mask;
198 	u32 offset, fw_status = 0;
199 	acpi_handle handle;
200 	unsigned int func;
201 	const u8 *uuid;
202 	int rc, i;
203 
204 	func = cmd;
205 	if (cmd == ND_CMD_CALL) {
206 		call_pkg = buf;
207 		func = call_pkg->nd_command;
208 	}
209 
210 	if (nvdimm) {
211 		struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
212 		struct acpi_device *adev = nfit_mem->adev;
213 
214 		if (!adev)
215 			return -ENOTTY;
216 		if (call_pkg && nfit_mem->family != call_pkg->nd_family)
217 			return -ENOTTY;
218 
219 		dimm_name = nvdimm_name(nvdimm);
220 		cmd_name = nvdimm_cmd_name(cmd);
221 		cmd_mask = nvdimm_cmd_mask(nvdimm);
222 		dsm_mask = nfit_mem->dsm_mask;
223 		desc = nd_cmd_dimm_desc(cmd);
224 		uuid = to_nfit_uuid(nfit_mem->family);
225 		handle = adev->handle;
226 	} else {
227 		struct acpi_device *adev = to_acpi_dev(acpi_desc);
228 
229 		cmd_name = nvdimm_bus_cmd_name(cmd);
230 		cmd_mask = nd_desc->cmd_mask;
231 		dsm_mask = cmd_mask;
232 		desc = nd_cmd_bus_desc(cmd);
233 		uuid = to_nfit_uuid(NFIT_DEV_BUS);
234 		handle = adev->handle;
235 		dimm_name = "bus";
236 	}
237 
238 	if (!desc || (cmd && (desc->out_num + desc->in_num == 0)))
239 		return -ENOTTY;
240 
241 	if (!test_bit(cmd, &cmd_mask) || !test_bit(func, &dsm_mask))
242 		return -ENOTTY;
243 
244 	in_obj.type = ACPI_TYPE_PACKAGE;
245 	in_obj.package.count = 1;
246 	in_obj.package.elements = &in_buf;
247 	in_buf.type = ACPI_TYPE_BUFFER;
248 	in_buf.buffer.pointer = buf;
249 	in_buf.buffer.length = 0;
250 
251 	/* libnvdimm has already validated the input envelope */
252 	for (i = 0; i < desc->in_num; i++)
253 		in_buf.buffer.length += nd_cmd_in_size(nvdimm, cmd, desc,
254 				i, buf);
255 
256 	if (call_pkg) {
257 		/* skip over package wrapper */
258 		in_buf.buffer.pointer = (void *) &call_pkg->nd_payload;
259 		in_buf.buffer.length = call_pkg->nd_size_in;
260 	}
261 
262 	if (IS_ENABLED(CONFIG_ACPI_NFIT_DEBUG)) {
263 		dev_dbg(dev, "%s:%s cmd: %d: func: %d input length: %d\n",
264 				__func__, dimm_name, cmd, func,
265 				in_buf.buffer.length);
266 		print_hex_dump_debug("nvdimm in  ", DUMP_PREFIX_OFFSET, 4, 4,
267 			in_buf.buffer.pointer,
268 			min_t(u32, 256, in_buf.buffer.length), true);
269 	}
270 
271 	out_obj = acpi_evaluate_dsm(handle, uuid, 1, func, &in_obj);
272 	if (!out_obj) {
273 		dev_dbg(dev, "%s:%s _DSM failed cmd: %s\n", __func__, dimm_name,
274 				cmd_name);
275 		return -EINVAL;
276 	}
277 
278 	if (call_pkg) {
279 		call_pkg->nd_fw_size = out_obj->buffer.length;
280 		memcpy(call_pkg->nd_payload + call_pkg->nd_size_in,
281 			out_obj->buffer.pointer,
282 			min(call_pkg->nd_fw_size, call_pkg->nd_size_out));
283 
284 		ACPI_FREE(out_obj);
285 		/*
286 		 * Need to support FW function w/o known size in advance.
287 		 * Caller can determine required size based upon nd_fw_size.
288 		 * If we return an error (like elsewhere) then caller wouldn't
289 		 * be able to rely upon data returned to make calculation.
290 		 */
291 		return 0;
292 	}
293 
294 	if (out_obj->package.type != ACPI_TYPE_BUFFER) {
295 		dev_dbg(dev, "%s:%s unexpected output object type cmd: %s type: %d\n",
296 				__func__, dimm_name, cmd_name, out_obj->type);
297 		rc = -EINVAL;
298 		goto out;
299 	}
300 
301 	if (IS_ENABLED(CONFIG_ACPI_NFIT_DEBUG)) {
302 		dev_dbg(dev, "%s:%s cmd: %s output length: %d\n", __func__,
303 				dimm_name, cmd_name, out_obj->buffer.length);
304 		print_hex_dump_debug(cmd_name, DUMP_PREFIX_OFFSET, 4,
305 				4, out_obj->buffer.pointer, min_t(u32, 128,
306 					out_obj->buffer.length), true);
307 	}
308 
309 	for (i = 0, offset = 0; i < desc->out_num; i++) {
310 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i, buf,
311 				(u32 *) out_obj->buffer.pointer,
312 				out_obj->buffer.length - offset);
313 
314 		if (offset + out_size > out_obj->buffer.length) {
315 			dev_dbg(dev, "%s:%s output object underflow cmd: %s field: %d\n",
316 					__func__, dimm_name, cmd_name, i);
317 			break;
318 		}
319 
320 		if (in_buf.buffer.length + offset + out_size > buf_len) {
321 			dev_dbg(dev, "%s:%s output overrun cmd: %s field: %d\n",
322 					__func__, dimm_name, cmd_name, i);
323 			rc = -ENXIO;
324 			goto out;
325 		}
326 		memcpy(buf + in_buf.buffer.length + offset,
327 				out_obj->buffer.pointer + offset, out_size);
328 		offset += out_size;
329 	}
330 
331 	/*
332 	 * Set fw_status for all the commands with a known format to be
333 	 * later interpreted by xlat_status().
334 	 */
335 	if (i >= 1 && ((cmd >= ND_CMD_ARS_CAP && cmd <= ND_CMD_CLEAR_ERROR)
336 			|| (cmd >= ND_CMD_SMART && cmd <= ND_CMD_VENDOR)))
337 		fw_status = *(u32 *) out_obj->buffer.pointer;
338 
339 	if (offset + in_buf.buffer.length < buf_len) {
340 		if (i >= 1) {
341 			/*
342 			 * status valid, return the number of bytes left
343 			 * unfilled in the output buffer
344 			 */
345 			rc = buf_len - offset - in_buf.buffer.length;
346 			if (cmd_rc)
347 				*cmd_rc = xlat_status(nvdimm, buf, cmd,
348 						fw_status);
349 		} else {
350 			dev_err(dev, "%s:%s underrun cmd: %s buf_len: %d out_len: %d\n",
351 					__func__, dimm_name, cmd_name, buf_len,
352 					offset);
353 			rc = -ENXIO;
354 		}
355 	} else {
356 		rc = 0;
357 		if (cmd_rc)
358 			*cmd_rc = xlat_status(nvdimm, buf, cmd, fw_status);
359 	}
360 
361  out:
362 	ACPI_FREE(out_obj);
363 
364 	return rc;
365 }
366 EXPORT_SYMBOL_GPL(acpi_nfit_ctl);
367 
368 static const char *spa_type_name(u16 type)
369 {
370 	static const char *to_name[] = {
371 		[NFIT_SPA_VOLATILE] = "volatile",
372 		[NFIT_SPA_PM] = "pmem",
373 		[NFIT_SPA_DCR] = "dimm-control-region",
374 		[NFIT_SPA_BDW] = "block-data-window",
375 		[NFIT_SPA_VDISK] = "volatile-disk",
376 		[NFIT_SPA_VCD] = "volatile-cd",
377 		[NFIT_SPA_PDISK] = "persistent-disk",
378 		[NFIT_SPA_PCD] = "persistent-cd",
379 
380 	};
381 
382 	if (type > NFIT_SPA_PCD)
383 		return "unknown";
384 
385 	return to_name[type];
386 }
387 
388 int nfit_spa_type(struct acpi_nfit_system_address *spa)
389 {
390 	int i;
391 
392 	for (i = 0; i < NFIT_UUID_MAX; i++)
393 		if (memcmp(to_nfit_uuid(i), spa->range_guid, 16) == 0)
394 			return i;
395 	return -1;
396 }
397 
398 static bool add_spa(struct acpi_nfit_desc *acpi_desc,
399 		struct nfit_table_prev *prev,
400 		struct acpi_nfit_system_address *spa)
401 {
402 	struct device *dev = acpi_desc->dev;
403 	struct nfit_spa *nfit_spa;
404 
405 	if (spa->header.length != sizeof(*spa))
406 		return false;
407 
408 	list_for_each_entry(nfit_spa, &prev->spas, list) {
409 		if (memcmp(nfit_spa->spa, spa, sizeof(*spa)) == 0) {
410 			list_move_tail(&nfit_spa->list, &acpi_desc->spas);
411 			return true;
412 		}
413 	}
414 
415 	nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa) + sizeof(*spa),
416 			GFP_KERNEL);
417 	if (!nfit_spa)
418 		return false;
419 	INIT_LIST_HEAD(&nfit_spa->list);
420 	memcpy(nfit_spa->spa, spa, sizeof(*spa));
421 	list_add_tail(&nfit_spa->list, &acpi_desc->spas);
422 	dev_dbg(dev, "%s: spa index: %d type: %s\n", __func__,
423 			spa->range_index,
424 			spa_type_name(nfit_spa_type(spa)));
425 	return true;
426 }
427 
428 static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
429 		struct nfit_table_prev *prev,
430 		struct acpi_nfit_memory_map *memdev)
431 {
432 	struct device *dev = acpi_desc->dev;
433 	struct nfit_memdev *nfit_memdev;
434 
435 	if (memdev->header.length != sizeof(*memdev))
436 		return false;
437 
438 	list_for_each_entry(nfit_memdev, &prev->memdevs, list)
439 		if (memcmp(nfit_memdev->memdev, memdev, sizeof(*memdev)) == 0) {
440 			list_move_tail(&nfit_memdev->list, &acpi_desc->memdevs);
441 			return true;
442 		}
443 
444 	nfit_memdev = devm_kzalloc(dev, sizeof(*nfit_memdev) + sizeof(*memdev),
445 			GFP_KERNEL);
446 	if (!nfit_memdev)
447 		return false;
448 	INIT_LIST_HEAD(&nfit_memdev->list);
449 	memcpy(nfit_memdev->memdev, memdev, sizeof(*memdev));
450 	list_add_tail(&nfit_memdev->list, &acpi_desc->memdevs);
451 	dev_dbg(dev, "%s: memdev handle: %#x spa: %d dcr: %d\n",
452 			__func__, memdev->device_handle, memdev->range_index,
453 			memdev->region_index);
454 	return true;
455 }
456 
457 /*
458  * An implementation may provide a truncated control region if no block windows
459  * are defined.
460  */
461 static size_t sizeof_dcr(struct acpi_nfit_control_region *dcr)
462 {
463 	if (dcr->header.length < offsetof(struct acpi_nfit_control_region,
464 				window_size))
465 		return 0;
466 	if (dcr->windows)
467 		return sizeof(*dcr);
468 	return offsetof(struct acpi_nfit_control_region, window_size);
469 }
470 
471 static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
472 		struct nfit_table_prev *prev,
473 		struct acpi_nfit_control_region *dcr)
474 {
475 	struct device *dev = acpi_desc->dev;
476 	struct nfit_dcr *nfit_dcr;
477 
478 	if (!sizeof_dcr(dcr))
479 		return false;
480 
481 	list_for_each_entry(nfit_dcr, &prev->dcrs, list)
482 		if (memcmp(nfit_dcr->dcr, dcr, sizeof_dcr(dcr)) == 0) {
483 			list_move_tail(&nfit_dcr->list, &acpi_desc->dcrs);
484 			return true;
485 		}
486 
487 	nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr) + sizeof(*dcr),
488 			GFP_KERNEL);
489 	if (!nfit_dcr)
490 		return false;
491 	INIT_LIST_HEAD(&nfit_dcr->list);
492 	memcpy(nfit_dcr->dcr, dcr, sizeof_dcr(dcr));
493 	list_add_tail(&nfit_dcr->list, &acpi_desc->dcrs);
494 	dev_dbg(dev, "%s: dcr index: %d windows: %d\n", __func__,
495 			dcr->region_index, dcr->windows);
496 	return true;
497 }
498 
499 static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
500 		struct nfit_table_prev *prev,
501 		struct acpi_nfit_data_region *bdw)
502 {
503 	struct device *dev = acpi_desc->dev;
504 	struct nfit_bdw *nfit_bdw;
505 
506 	if (bdw->header.length != sizeof(*bdw))
507 		return false;
508 	list_for_each_entry(nfit_bdw, &prev->bdws, list)
509 		if (memcmp(nfit_bdw->bdw, bdw, sizeof(*bdw)) == 0) {
510 			list_move_tail(&nfit_bdw->list, &acpi_desc->bdws);
511 			return true;
512 		}
513 
514 	nfit_bdw = devm_kzalloc(dev, sizeof(*nfit_bdw) + sizeof(*bdw),
515 			GFP_KERNEL);
516 	if (!nfit_bdw)
517 		return false;
518 	INIT_LIST_HEAD(&nfit_bdw->list);
519 	memcpy(nfit_bdw->bdw, bdw, sizeof(*bdw));
520 	list_add_tail(&nfit_bdw->list, &acpi_desc->bdws);
521 	dev_dbg(dev, "%s: bdw dcr: %d windows: %d\n", __func__,
522 			bdw->region_index, bdw->windows);
523 	return true;
524 }
525 
526 static size_t sizeof_idt(struct acpi_nfit_interleave *idt)
527 {
528 	if (idt->header.length < sizeof(*idt))
529 		return 0;
530 	return sizeof(*idt) + sizeof(u32) * (idt->line_count - 1);
531 }
532 
533 static bool add_idt(struct acpi_nfit_desc *acpi_desc,
534 		struct nfit_table_prev *prev,
535 		struct acpi_nfit_interleave *idt)
536 {
537 	struct device *dev = acpi_desc->dev;
538 	struct nfit_idt *nfit_idt;
539 
540 	if (!sizeof_idt(idt))
541 		return false;
542 
543 	list_for_each_entry(nfit_idt, &prev->idts, list) {
544 		if (sizeof_idt(nfit_idt->idt) != sizeof_idt(idt))
545 			continue;
546 
547 		if (memcmp(nfit_idt->idt, idt, sizeof_idt(idt)) == 0) {
548 			list_move_tail(&nfit_idt->list, &acpi_desc->idts);
549 			return true;
550 		}
551 	}
552 
553 	nfit_idt = devm_kzalloc(dev, sizeof(*nfit_idt) + sizeof_idt(idt),
554 			GFP_KERNEL);
555 	if (!nfit_idt)
556 		return false;
557 	INIT_LIST_HEAD(&nfit_idt->list);
558 	memcpy(nfit_idt->idt, idt, sizeof_idt(idt));
559 	list_add_tail(&nfit_idt->list, &acpi_desc->idts);
560 	dev_dbg(dev, "%s: idt index: %d num_lines: %d\n", __func__,
561 			idt->interleave_index, idt->line_count);
562 	return true;
563 }
564 
565 static size_t sizeof_flush(struct acpi_nfit_flush_address *flush)
566 {
567 	if (flush->header.length < sizeof(*flush))
568 		return 0;
569 	return sizeof(*flush) + sizeof(u64) * (flush->hint_count - 1);
570 }
571 
572 static bool add_flush(struct acpi_nfit_desc *acpi_desc,
573 		struct nfit_table_prev *prev,
574 		struct acpi_nfit_flush_address *flush)
575 {
576 	struct device *dev = acpi_desc->dev;
577 	struct nfit_flush *nfit_flush;
578 
579 	if (!sizeof_flush(flush))
580 		return false;
581 
582 	list_for_each_entry(nfit_flush, &prev->flushes, list) {
583 		if (sizeof_flush(nfit_flush->flush) != sizeof_flush(flush))
584 			continue;
585 
586 		if (memcmp(nfit_flush->flush, flush,
587 					sizeof_flush(flush)) == 0) {
588 			list_move_tail(&nfit_flush->list, &acpi_desc->flushes);
589 			return true;
590 		}
591 	}
592 
593 	nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush)
594 			+ sizeof_flush(flush), GFP_KERNEL);
595 	if (!nfit_flush)
596 		return false;
597 	INIT_LIST_HEAD(&nfit_flush->list);
598 	memcpy(nfit_flush->flush, flush, sizeof_flush(flush));
599 	list_add_tail(&nfit_flush->list, &acpi_desc->flushes);
600 	dev_dbg(dev, "%s: nfit_flush handle: %d hint_count: %d\n", __func__,
601 			flush->device_handle, flush->hint_count);
602 	return true;
603 }
604 
605 static void *add_table(struct acpi_nfit_desc *acpi_desc,
606 		struct nfit_table_prev *prev, void *table, const void *end)
607 {
608 	struct device *dev = acpi_desc->dev;
609 	struct acpi_nfit_header *hdr;
610 	void *err = ERR_PTR(-ENOMEM);
611 
612 	if (table >= end)
613 		return NULL;
614 
615 	hdr = table;
616 	if (!hdr->length) {
617 		dev_warn(dev, "found a zero length table '%d' parsing nfit\n",
618 			hdr->type);
619 		return NULL;
620 	}
621 
622 	switch (hdr->type) {
623 	case ACPI_NFIT_TYPE_SYSTEM_ADDRESS:
624 		if (!add_spa(acpi_desc, prev, table))
625 			return err;
626 		break;
627 	case ACPI_NFIT_TYPE_MEMORY_MAP:
628 		if (!add_memdev(acpi_desc, prev, table))
629 			return err;
630 		break;
631 	case ACPI_NFIT_TYPE_CONTROL_REGION:
632 		if (!add_dcr(acpi_desc, prev, table))
633 			return err;
634 		break;
635 	case ACPI_NFIT_TYPE_DATA_REGION:
636 		if (!add_bdw(acpi_desc, prev, table))
637 			return err;
638 		break;
639 	case ACPI_NFIT_TYPE_INTERLEAVE:
640 		if (!add_idt(acpi_desc, prev, table))
641 			return err;
642 		break;
643 	case ACPI_NFIT_TYPE_FLUSH_ADDRESS:
644 		if (!add_flush(acpi_desc, prev, table))
645 			return err;
646 		break;
647 	case ACPI_NFIT_TYPE_SMBIOS:
648 		dev_dbg(dev, "%s: smbios\n", __func__);
649 		break;
650 	default:
651 		dev_err(dev, "unknown table '%d' parsing nfit\n", hdr->type);
652 		break;
653 	}
654 
655 	return table + hdr->length;
656 }
657 
658 static void nfit_mem_find_spa_bdw(struct acpi_nfit_desc *acpi_desc,
659 		struct nfit_mem *nfit_mem)
660 {
661 	u32 device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
662 	u16 dcr = nfit_mem->dcr->region_index;
663 	struct nfit_spa *nfit_spa;
664 
665 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
666 		u16 range_index = nfit_spa->spa->range_index;
667 		int type = nfit_spa_type(nfit_spa->spa);
668 		struct nfit_memdev *nfit_memdev;
669 
670 		if (type != NFIT_SPA_BDW)
671 			continue;
672 
673 		list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
674 			if (nfit_memdev->memdev->range_index != range_index)
675 				continue;
676 			if (nfit_memdev->memdev->device_handle != device_handle)
677 				continue;
678 			if (nfit_memdev->memdev->region_index != dcr)
679 				continue;
680 
681 			nfit_mem->spa_bdw = nfit_spa->spa;
682 			return;
683 		}
684 	}
685 
686 	dev_dbg(acpi_desc->dev, "SPA-BDW not found for SPA-DCR %d\n",
687 			nfit_mem->spa_dcr->range_index);
688 	nfit_mem->bdw = NULL;
689 }
690 
691 static void nfit_mem_init_bdw(struct acpi_nfit_desc *acpi_desc,
692 		struct nfit_mem *nfit_mem, struct acpi_nfit_system_address *spa)
693 {
694 	u16 dcr = __to_nfit_memdev(nfit_mem)->region_index;
695 	struct nfit_memdev *nfit_memdev;
696 	struct nfit_bdw *nfit_bdw;
697 	struct nfit_idt *nfit_idt;
698 	u16 idt_idx, range_index;
699 
700 	list_for_each_entry(nfit_bdw, &acpi_desc->bdws, list) {
701 		if (nfit_bdw->bdw->region_index != dcr)
702 			continue;
703 		nfit_mem->bdw = nfit_bdw->bdw;
704 		break;
705 	}
706 
707 	if (!nfit_mem->bdw)
708 		return;
709 
710 	nfit_mem_find_spa_bdw(acpi_desc, nfit_mem);
711 
712 	if (!nfit_mem->spa_bdw)
713 		return;
714 
715 	range_index = nfit_mem->spa_bdw->range_index;
716 	list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
717 		if (nfit_memdev->memdev->range_index != range_index ||
718 				nfit_memdev->memdev->region_index != dcr)
719 			continue;
720 		nfit_mem->memdev_bdw = nfit_memdev->memdev;
721 		idt_idx = nfit_memdev->memdev->interleave_index;
722 		list_for_each_entry(nfit_idt, &acpi_desc->idts, list) {
723 			if (nfit_idt->idt->interleave_index != idt_idx)
724 				continue;
725 			nfit_mem->idt_bdw = nfit_idt->idt;
726 			break;
727 		}
728 		break;
729 	}
730 }
731 
732 static int nfit_mem_dcr_init(struct acpi_nfit_desc *acpi_desc,
733 		struct acpi_nfit_system_address *spa)
734 {
735 	struct nfit_mem *nfit_mem, *found;
736 	struct nfit_memdev *nfit_memdev;
737 	int type = nfit_spa_type(spa);
738 
739 	switch (type) {
740 	case NFIT_SPA_DCR:
741 	case NFIT_SPA_PM:
742 		break;
743 	default:
744 		return 0;
745 	}
746 
747 	list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
748 		struct nfit_flush *nfit_flush;
749 		struct nfit_dcr *nfit_dcr;
750 		u32 device_handle;
751 		u16 dcr;
752 
753 		if (nfit_memdev->memdev->range_index != spa->range_index)
754 			continue;
755 		found = NULL;
756 		dcr = nfit_memdev->memdev->region_index;
757 		device_handle = nfit_memdev->memdev->device_handle;
758 		list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
759 			if (__to_nfit_memdev(nfit_mem)->device_handle
760 					== device_handle) {
761 				found = nfit_mem;
762 				break;
763 			}
764 
765 		if (found)
766 			nfit_mem = found;
767 		else {
768 			nfit_mem = devm_kzalloc(acpi_desc->dev,
769 					sizeof(*nfit_mem), GFP_KERNEL);
770 			if (!nfit_mem)
771 				return -ENOMEM;
772 			INIT_LIST_HEAD(&nfit_mem->list);
773 			nfit_mem->acpi_desc = acpi_desc;
774 			list_add(&nfit_mem->list, &acpi_desc->dimms);
775 		}
776 
777 		list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
778 			if (nfit_dcr->dcr->region_index != dcr)
779 				continue;
780 			/*
781 			 * Record the control region for the dimm.  For
782 			 * the ACPI 6.1 case, where there are separate
783 			 * control regions for the pmem vs blk
784 			 * interfaces, be sure to record the extended
785 			 * blk details.
786 			 */
787 			if (!nfit_mem->dcr)
788 				nfit_mem->dcr = nfit_dcr->dcr;
789 			else if (nfit_mem->dcr->windows == 0
790 					&& nfit_dcr->dcr->windows)
791 				nfit_mem->dcr = nfit_dcr->dcr;
792 			break;
793 		}
794 
795 		list_for_each_entry(nfit_flush, &acpi_desc->flushes, list) {
796 			struct acpi_nfit_flush_address *flush;
797 			u16 i;
798 
799 			if (nfit_flush->flush->device_handle != device_handle)
800 				continue;
801 			nfit_mem->nfit_flush = nfit_flush;
802 			flush = nfit_flush->flush;
803 			nfit_mem->flush_wpq = devm_kzalloc(acpi_desc->dev,
804 					flush->hint_count
805 					* sizeof(struct resource), GFP_KERNEL);
806 			if (!nfit_mem->flush_wpq)
807 				return -ENOMEM;
808 			for (i = 0; i < flush->hint_count; i++) {
809 				struct resource *res = &nfit_mem->flush_wpq[i];
810 
811 				res->start = flush->hint_address[i];
812 				res->end = res->start + 8 - 1;
813 			}
814 			break;
815 		}
816 
817 		if (dcr && !nfit_mem->dcr) {
818 			dev_err(acpi_desc->dev, "SPA %d missing DCR %d\n",
819 					spa->range_index, dcr);
820 			return -ENODEV;
821 		}
822 
823 		if (type == NFIT_SPA_DCR) {
824 			struct nfit_idt *nfit_idt;
825 			u16 idt_idx;
826 
827 			/* multiple dimms may share a SPA when interleaved */
828 			nfit_mem->spa_dcr = spa;
829 			nfit_mem->memdev_dcr = nfit_memdev->memdev;
830 			idt_idx = nfit_memdev->memdev->interleave_index;
831 			list_for_each_entry(nfit_idt, &acpi_desc->idts, list) {
832 				if (nfit_idt->idt->interleave_index != idt_idx)
833 					continue;
834 				nfit_mem->idt_dcr = nfit_idt->idt;
835 				break;
836 			}
837 			nfit_mem_init_bdw(acpi_desc, nfit_mem, spa);
838 		} else {
839 			/*
840 			 * A single dimm may belong to multiple SPA-PM
841 			 * ranges, record at least one in addition to
842 			 * any SPA-DCR range.
843 			 */
844 			nfit_mem->memdev_pmem = nfit_memdev->memdev;
845 		}
846 	}
847 
848 	return 0;
849 }
850 
851 static int nfit_mem_cmp(void *priv, struct list_head *_a, struct list_head *_b)
852 {
853 	struct nfit_mem *a = container_of(_a, typeof(*a), list);
854 	struct nfit_mem *b = container_of(_b, typeof(*b), list);
855 	u32 handleA, handleB;
856 
857 	handleA = __to_nfit_memdev(a)->device_handle;
858 	handleB = __to_nfit_memdev(b)->device_handle;
859 	if (handleA < handleB)
860 		return -1;
861 	else if (handleA > handleB)
862 		return 1;
863 	return 0;
864 }
865 
866 static int nfit_mem_init(struct acpi_nfit_desc *acpi_desc)
867 {
868 	struct nfit_spa *nfit_spa;
869 
870 	/*
871 	 * For each SPA-DCR or SPA-PMEM address range find its
872 	 * corresponding MEMDEV(s).  From each MEMDEV find the
873 	 * corresponding DCR.  Then, if we're operating on a SPA-DCR,
874 	 * try to find a SPA-BDW and a corresponding BDW that references
875 	 * the DCR.  Throw it all into an nfit_mem object.  Note, that
876 	 * BDWs are optional.
877 	 */
878 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
879 		int rc;
880 
881 		rc = nfit_mem_dcr_init(acpi_desc, nfit_spa->spa);
882 		if (rc)
883 			return rc;
884 	}
885 
886 	list_sort(NULL, &acpi_desc->dimms, nfit_mem_cmp);
887 
888 	return 0;
889 }
890 
891 static ssize_t revision_show(struct device *dev,
892 		struct device_attribute *attr, char *buf)
893 {
894 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
895 	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
896 	struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
897 
898 	return sprintf(buf, "%d\n", acpi_desc->acpi_header.revision);
899 }
900 static DEVICE_ATTR_RO(revision);
901 
902 static ssize_t hw_error_scrub_show(struct device *dev,
903 		struct device_attribute *attr, char *buf)
904 {
905 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
906 	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
907 	struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
908 
909 	return sprintf(buf, "%d\n", acpi_desc->scrub_mode);
910 }
911 
912 /*
913  * The 'hw_error_scrub' attribute can have the following values written to it:
914  * '0': Switch to the default mode where an exception will only insert
915  *      the address of the memory error into the poison and badblocks lists.
916  * '1': Enable a full scrub to happen if an exception for a memory error is
917  *      received.
918  */
919 static ssize_t hw_error_scrub_store(struct device *dev,
920 		struct device_attribute *attr, const char *buf, size_t size)
921 {
922 	struct nvdimm_bus_descriptor *nd_desc;
923 	ssize_t rc;
924 	long val;
925 
926 	rc = kstrtol(buf, 0, &val);
927 	if (rc)
928 		return rc;
929 
930 	device_lock(dev);
931 	nd_desc = dev_get_drvdata(dev);
932 	if (nd_desc) {
933 		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
934 
935 		switch (val) {
936 		case HW_ERROR_SCRUB_ON:
937 			acpi_desc->scrub_mode = HW_ERROR_SCRUB_ON;
938 			break;
939 		case HW_ERROR_SCRUB_OFF:
940 			acpi_desc->scrub_mode = HW_ERROR_SCRUB_OFF;
941 			break;
942 		default:
943 			rc = -EINVAL;
944 			break;
945 		}
946 	}
947 	device_unlock(dev);
948 	if (rc)
949 		return rc;
950 	return size;
951 }
952 static DEVICE_ATTR_RW(hw_error_scrub);
953 
954 /*
955  * This shows the number of full Address Range Scrubs that have been
956  * completed since driver load time. Userspace can wait on this using
957  * select/poll etc. A '+' at the end indicates an ARS is in progress
958  */
959 static ssize_t scrub_show(struct device *dev,
960 		struct device_attribute *attr, char *buf)
961 {
962 	struct nvdimm_bus_descriptor *nd_desc;
963 	ssize_t rc = -ENXIO;
964 
965 	device_lock(dev);
966 	nd_desc = dev_get_drvdata(dev);
967 	if (nd_desc) {
968 		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
969 
970 		rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,
971 				(work_busy(&acpi_desc->work)) ? "+\n" : "\n");
972 	}
973 	device_unlock(dev);
974 	return rc;
975 }
976 
977 static ssize_t scrub_store(struct device *dev,
978 		struct device_attribute *attr, const char *buf, size_t size)
979 {
980 	struct nvdimm_bus_descriptor *nd_desc;
981 	ssize_t rc;
982 	long val;
983 
984 	rc = kstrtol(buf, 0, &val);
985 	if (rc)
986 		return rc;
987 	if (val != 1)
988 		return -EINVAL;
989 
990 	device_lock(dev);
991 	nd_desc = dev_get_drvdata(dev);
992 	if (nd_desc) {
993 		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
994 
995 		rc = acpi_nfit_ars_rescan(acpi_desc);
996 	}
997 	device_unlock(dev);
998 	if (rc)
999 		return rc;
1000 	return size;
1001 }
1002 static DEVICE_ATTR_RW(scrub);
1003 
1004 static bool ars_supported(struct nvdimm_bus *nvdimm_bus)
1005 {
1006 	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
1007 	const unsigned long mask = 1 << ND_CMD_ARS_CAP | 1 << ND_CMD_ARS_START
1008 		| 1 << ND_CMD_ARS_STATUS;
1009 
1010 	return (nd_desc->cmd_mask & mask) == mask;
1011 }
1012 
1013 static umode_t nfit_visible(struct kobject *kobj, struct attribute *a, int n)
1014 {
1015 	struct device *dev = container_of(kobj, struct device, kobj);
1016 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
1017 
1018 	if (a == &dev_attr_scrub.attr && !ars_supported(nvdimm_bus))
1019 		return 0;
1020 	return a->mode;
1021 }
1022 
1023 static struct attribute *acpi_nfit_attributes[] = {
1024 	&dev_attr_revision.attr,
1025 	&dev_attr_scrub.attr,
1026 	&dev_attr_hw_error_scrub.attr,
1027 	NULL,
1028 };
1029 
1030 static struct attribute_group acpi_nfit_attribute_group = {
1031 	.name = "nfit",
1032 	.attrs = acpi_nfit_attributes,
1033 	.is_visible = nfit_visible,
1034 };
1035 
1036 static const struct attribute_group *acpi_nfit_attribute_groups[] = {
1037 	&nvdimm_bus_attribute_group,
1038 	&acpi_nfit_attribute_group,
1039 	NULL,
1040 };
1041 
1042 static struct acpi_nfit_memory_map *to_nfit_memdev(struct device *dev)
1043 {
1044 	struct nvdimm *nvdimm = to_nvdimm(dev);
1045 	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1046 
1047 	return __to_nfit_memdev(nfit_mem);
1048 }
1049 
1050 static struct acpi_nfit_control_region *to_nfit_dcr(struct device *dev)
1051 {
1052 	struct nvdimm *nvdimm = to_nvdimm(dev);
1053 	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1054 
1055 	return nfit_mem->dcr;
1056 }
1057 
1058 static ssize_t handle_show(struct device *dev,
1059 		struct device_attribute *attr, char *buf)
1060 {
1061 	struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);
1062 
1063 	return sprintf(buf, "%#x\n", memdev->device_handle);
1064 }
1065 static DEVICE_ATTR_RO(handle);
1066 
1067 static ssize_t phys_id_show(struct device *dev,
1068 		struct device_attribute *attr, char *buf)
1069 {
1070 	struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);
1071 
1072 	return sprintf(buf, "%#x\n", memdev->physical_id);
1073 }
1074 static DEVICE_ATTR_RO(phys_id);
1075 
1076 static ssize_t vendor_show(struct device *dev,
1077 		struct device_attribute *attr, char *buf)
1078 {
1079 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1080 
1081 	return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->vendor_id));
1082 }
1083 static DEVICE_ATTR_RO(vendor);
1084 
1085 static ssize_t rev_id_show(struct device *dev,
1086 		struct device_attribute *attr, char *buf)
1087 {
1088 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1089 
1090 	return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->revision_id));
1091 }
1092 static DEVICE_ATTR_RO(rev_id);
1093 
1094 static ssize_t device_show(struct device *dev,
1095 		struct device_attribute *attr, char *buf)
1096 {
1097 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1098 
1099 	return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->device_id));
1100 }
1101 static DEVICE_ATTR_RO(device);
1102 
1103 static ssize_t subsystem_vendor_show(struct device *dev,
1104 		struct device_attribute *attr, char *buf)
1105 {
1106 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1107 
1108 	return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->subsystem_vendor_id));
1109 }
1110 static DEVICE_ATTR_RO(subsystem_vendor);
1111 
1112 static ssize_t subsystem_rev_id_show(struct device *dev,
1113 		struct device_attribute *attr, char *buf)
1114 {
1115 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1116 
1117 	return sprintf(buf, "0x%04x\n",
1118 			be16_to_cpu(dcr->subsystem_revision_id));
1119 }
1120 static DEVICE_ATTR_RO(subsystem_rev_id);
1121 
1122 static ssize_t subsystem_device_show(struct device *dev,
1123 		struct device_attribute *attr, char *buf)
1124 {
1125 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1126 
1127 	return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->subsystem_device_id));
1128 }
1129 static DEVICE_ATTR_RO(subsystem_device);
1130 
1131 static int num_nvdimm_formats(struct nvdimm *nvdimm)
1132 {
1133 	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1134 	int formats = 0;
1135 
1136 	if (nfit_mem->memdev_pmem)
1137 		formats++;
1138 	if (nfit_mem->memdev_bdw)
1139 		formats++;
1140 	return formats;
1141 }
1142 
1143 static ssize_t format_show(struct device *dev,
1144 		struct device_attribute *attr, char *buf)
1145 {
1146 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1147 
1148 	return sprintf(buf, "0x%04x\n", le16_to_cpu(dcr->code));
1149 }
1150 static DEVICE_ATTR_RO(format);
1151 
1152 static ssize_t format1_show(struct device *dev,
1153 		struct device_attribute *attr, char *buf)
1154 {
1155 	u32 handle;
1156 	ssize_t rc = -ENXIO;
1157 	struct nfit_mem *nfit_mem;
1158 	struct nfit_memdev *nfit_memdev;
1159 	struct acpi_nfit_desc *acpi_desc;
1160 	struct nvdimm *nvdimm = to_nvdimm(dev);
1161 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1162 
1163 	nfit_mem = nvdimm_provider_data(nvdimm);
1164 	acpi_desc = nfit_mem->acpi_desc;
1165 	handle = to_nfit_memdev(dev)->device_handle;
1166 
1167 	/* assumes DIMMs have at most 2 published interface codes */
1168 	mutex_lock(&acpi_desc->init_mutex);
1169 	list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
1170 		struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev;
1171 		struct nfit_dcr *nfit_dcr;
1172 
1173 		if (memdev->device_handle != handle)
1174 			continue;
1175 
1176 		list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
1177 			if (nfit_dcr->dcr->region_index != memdev->region_index)
1178 				continue;
1179 			if (nfit_dcr->dcr->code == dcr->code)
1180 				continue;
1181 			rc = sprintf(buf, "0x%04x\n",
1182 					le16_to_cpu(nfit_dcr->dcr->code));
1183 			break;
1184 		}
1185 		if (rc != ENXIO)
1186 			break;
1187 	}
1188 	mutex_unlock(&acpi_desc->init_mutex);
1189 	return rc;
1190 }
1191 static DEVICE_ATTR_RO(format1);
1192 
1193 static ssize_t formats_show(struct device *dev,
1194 		struct device_attribute *attr, char *buf)
1195 {
1196 	struct nvdimm *nvdimm = to_nvdimm(dev);
1197 
1198 	return sprintf(buf, "%d\n", num_nvdimm_formats(nvdimm));
1199 }
1200 static DEVICE_ATTR_RO(formats);
1201 
1202 static ssize_t serial_show(struct device *dev,
1203 		struct device_attribute *attr, char *buf)
1204 {
1205 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1206 
1207 	return sprintf(buf, "0x%08x\n", be32_to_cpu(dcr->serial_number));
1208 }
1209 static DEVICE_ATTR_RO(serial);
1210 
1211 static ssize_t family_show(struct device *dev,
1212 		struct device_attribute *attr, char *buf)
1213 {
1214 	struct nvdimm *nvdimm = to_nvdimm(dev);
1215 	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1216 
1217 	if (nfit_mem->family < 0)
1218 		return -ENXIO;
1219 	return sprintf(buf, "%d\n", nfit_mem->family);
1220 }
1221 static DEVICE_ATTR_RO(family);
1222 
1223 static ssize_t dsm_mask_show(struct device *dev,
1224 		struct device_attribute *attr, char *buf)
1225 {
1226 	struct nvdimm *nvdimm = to_nvdimm(dev);
1227 	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1228 
1229 	if (nfit_mem->family < 0)
1230 		return -ENXIO;
1231 	return sprintf(buf, "%#lx\n", nfit_mem->dsm_mask);
1232 }
1233 static DEVICE_ATTR_RO(dsm_mask);
1234 
1235 static ssize_t flags_show(struct device *dev,
1236 		struct device_attribute *attr, char *buf)
1237 {
1238 	u16 flags = to_nfit_memdev(dev)->flags;
1239 
1240 	return sprintf(buf, "%s%s%s%s%s\n",
1241 		flags & ACPI_NFIT_MEM_SAVE_FAILED ? "save_fail " : "",
1242 		flags & ACPI_NFIT_MEM_RESTORE_FAILED ? "restore_fail " : "",
1243 		flags & ACPI_NFIT_MEM_FLUSH_FAILED ? "flush_fail " : "",
1244 		flags & ACPI_NFIT_MEM_NOT_ARMED ? "not_armed " : "",
1245 		flags & ACPI_NFIT_MEM_HEALTH_OBSERVED ? "smart_event " : "");
1246 }
1247 static DEVICE_ATTR_RO(flags);
1248 
1249 static ssize_t id_show(struct device *dev,
1250 		struct device_attribute *attr, char *buf)
1251 {
1252 	struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
1253 
1254 	if (dcr->valid_fields & ACPI_NFIT_CONTROL_MFG_INFO_VALID)
1255 		return sprintf(buf, "%04x-%02x-%04x-%08x\n",
1256 				be16_to_cpu(dcr->vendor_id),
1257 				dcr->manufacturing_location,
1258 				be16_to_cpu(dcr->manufacturing_date),
1259 				be32_to_cpu(dcr->serial_number));
1260 	else
1261 		return sprintf(buf, "%04x-%08x\n",
1262 				be16_to_cpu(dcr->vendor_id),
1263 				be32_to_cpu(dcr->serial_number));
1264 }
1265 static DEVICE_ATTR_RO(id);
1266 
1267 static struct attribute *acpi_nfit_dimm_attributes[] = {
1268 	&dev_attr_handle.attr,
1269 	&dev_attr_phys_id.attr,
1270 	&dev_attr_vendor.attr,
1271 	&dev_attr_device.attr,
1272 	&dev_attr_rev_id.attr,
1273 	&dev_attr_subsystem_vendor.attr,
1274 	&dev_attr_subsystem_device.attr,
1275 	&dev_attr_subsystem_rev_id.attr,
1276 	&dev_attr_format.attr,
1277 	&dev_attr_formats.attr,
1278 	&dev_attr_format1.attr,
1279 	&dev_attr_serial.attr,
1280 	&dev_attr_flags.attr,
1281 	&dev_attr_id.attr,
1282 	&dev_attr_family.attr,
1283 	&dev_attr_dsm_mask.attr,
1284 	NULL,
1285 };
1286 
1287 static umode_t acpi_nfit_dimm_attr_visible(struct kobject *kobj,
1288 		struct attribute *a, int n)
1289 {
1290 	struct device *dev = container_of(kobj, struct device, kobj);
1291 	struct nvdimm *nvdimm = to_nvdimm(dev);
1292 
1293 	if (!to_nfit_dcr(dev))
1294 		return 0;
1295 	if (a == &dev_attr_format1.attr && num_nvdimm_formats(nvdimm) <= 1)
1296 		return 0;
1297 	return a->mode;
1298 }
1299 
1300 static struct attribute_group acpi_nfit_dimm_attribute_group = {
1301 	.name = "nfit",
1302 	.attrs = acpi_nfit_dimm_attributes,
1303 	.is_visible = acpi_nfit_dimm_attr_visible,
1304 };
1305 
1306 static const struct attribute_group *acpi_nfit_dimm_attribute_groups[] = {
1307 	&nvdimm_attribute_group,
1308 	&nd_device_attribute_group,
1309 	&acpi_nfit_dimm_attribute_group,
1310 	NULL,
1311 };
1312 
1313 static struct nvdimm *acpi_nfit_dimm_by_handle(struct acpi_nfit_desc *acpi_desc,
1314 		u32 device_handle)
1315 {
1316 	struct nfit_mem *nfit_mem;
1317 
1318 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
1319 		if (__to_nfit_memdev(nfit_mem)->device_handle == device_handle)
1320 			return nfit_mem->nvdimm;
1321 
1322 	return NULL;
1323 }
1324 
1325 void __acpi_nvdimm_notify(struct device *dev, u32 event)
1326 {
1327 	struct nfit_mem *nfit_mem;
1328 	struct acpi_nfit_desc *acpi_desc;
1329 
1330 	dev_dbg(dev->parent, "%s: %s: event: %d\n", dev_name(dev), __func__,
1331 			event);
1332 
1333 	if (event != NFIT_NOTIFY_DIMM_HEALTH) {
1334 		dev_dbg(dev->parent, "%s: unknown event: %d\n", dev_name(dev),
1335 				event);
1336 		return;
1337 	}
1338 
1339 	acpi_desc = dev_get_drvdata(dev->parent);
1340 	if (!acpi_desc)
1341 		return;
1342 
1343 	/*
1344 	 * If we successfully retrieved acpi_desc, then we know nfit_mem data
1345 	 * is still valid.
1346 	 */
1347 	nfit_mem = dev_get_drvdata(dev);
1348 	if (nfit_mem && nfit_mem->flags_attr)
1349 		sysfs_notify_dirent(nfit_mem->flags_attr);
1350 }
1351 EXPORT_SYMBOL_GPL(__acpi_nvdimm_notify);
1352 
1353 static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
1354 {
1355 	struct acpi_device *adev = data;
1356 	struct device *dev = &adev->dev;
1357 
1358 	device_lock(dev->parent);
1359 	__acpi_nvdimm_notify(dev, event);
1360 	device_unlock(dev->parent);
1361 }
1362 
1363 static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
1364 		struct nfit_mem *nfit_mem, u32 device_handle)
1365 {
1366 	struct acpi_device *adev, *adev_dimm;
1367 	struct device *dev = acpi_desc->dev;
1368 	unsigned long dsm_mask;
1369 	const u8 *uuid;
1370 	int i;
1371 
1372 	/* nfit test assumes 1:1 relationship between commands and dsms */
1373 	nfit_mem->dsm_mask = acpi_desc->dimm_cmd_force_en;
1374 	nfit_mem->family = NVDIMM_FAMILY_INTEL;
1375 	adev = to_acpi_dev(acpi_desc);
1376 	if (!adev)
1377 		return 0;
1378 
1379 	adev_dimm = acpi_find_child_device(adev, device_handle, false);
1380 	nfit_mem->adev = adev_dimm;
1381 	if (!adev_dimm) {
1382 		dev_err(dev, "no ACPI.NFIT device with _ADR %#x, disabling...\n",
1383 				device_handle);
1384 		return force_enable_dimms ? 0 : -ENODEV;
1385 	}
1386 
1387 	if (ACPI_FAILURE(acpi_install_notify_handler(adev_dimm->handle,
1388 		ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify, adev_dimm))) {
1389 		dev_err(dev, "%s: notification registration failed\n",
1390 				dev_name(&adev_dimm->dev));
1391 		return -ENXIO;
1392 	}
1393 
1394 	/*
1395 	 * Until standardization materializes we need to consider 4
1396 	 * different command sets.  Note, that checking for function0 (bit0)
1397 	 * tells us if any commands are reachable through this uuid.
1398 	 */
1399 	for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_MSFT; i++)
1400 		if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
1401 			break;
1402 
1403 	/* limit the supported commands to those that are publicly documented */
1404 	nfit_mem->family = i;
1405 	if (nfit_mem->family == NVDIMM_FAMILY_INTEL) {
1406 		dsm_mask = 0x3fe;
1407 		if (disable_vendor_specific)
1408 			dsm_mask &= ~(1 << ND_CMD_VENDOR);
1409 	} else if (nfit_mem->family == NVDIMM_FAMILY_HPE1) {
1410 		dsm_mask = 0x1c3c76;
1411 	} else if (nfit_mem->family == NVDIMM_FAMILY_HPE2) {
1412 		dsm_mask = 0x1fe;
1413 		if (disable_vendor_specific)
1414 			dsm_mask &= ~(1 << 8);
1415 	} else if (nfit_mem->family == NVDIMM_FAMILY_MSFT) {
1416 		dsm_mask = 0xffffffff;
1417 	} else {
1418 		dev_dbg(dev, "unknown dimm command family\n");
1419 		nfit_mem->family = -1;
1420 		/* DSMs are optional, continue loading the driver... */
1421 		return 0;
1422 	}
1423 
1424 	uuid = to_nfit_uuid(nfit_mem->family);
1425 	for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
1426 		if (acpi_check_dsm(adev_dimm->handle, uuid, 1, 1ULL << i))
1427 			set_bit(i, &nfit_mem->dsm_mask);
1428 
1429 	return 0;
1430 }
1431 
1432 static void shutdown_dimm_notify(void *data)
1433 {
1434 	struct acpi_nfit_desc *acpi_desc = data;
1435 	struct nfit_mem *nfit_mem;
1436 
1437 	mutex_lock(&acpi_desc->init_mutex);
1438 	/*
1439 	 * Clear out the nfit_mem->flags_attr and shut down dimm event
1440 	 * notifications.
1441 	 */
1442 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
1443 		struct acpi_device *adev_dimm = nfit_mem->adev;
1444 
1445 		if (nfit_mem->flags_attr) {
1446 			sysfs_put(nfit_mem->flags_attr);
1447 			nfit_mem->flags_attr = NULL;
1448 		}
1449 		if (adev_dimm)
1450 			acpi_remove_notify_handler(adev_dimm->handle,
1451 					ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify);
1452 	}
1453 	mutex_unlock(&acpi_desc->init_mutex);
1454 }
1455 
1456 static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
1457 {
1458 	struct nfit_mem *nfit_mem;
1459 	int dimm_count = 0, rc;
1460 	struct nvdimm *nvdimm;
1461 
1462 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
1463 		struct acpi_nfit_flush_address *flush;
1464 		unsigned long flags = 0, cmd_mask;
1465 		u32 device_handle;
1466 		u16 mem_flags;
1467 
1468 		device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
1469 		nvdimm = acpi_nfit_dimm_by_handle(acpi_desc, device_handle);
1470 		if (nvdimm) {
1471 			dimm_count++;
1472 			continue;
1473 		}
1474 
1475 		if (nfit_mem->bdw && nfit_mem->memdev_pmem)
1476 			flags |= NDD_ALIASING;
1477 
1478 		mem_flags = __to_nfit_memdev(nfit_mem)->flags;
1479 		if (mem_flags & ACPI_NFIT_MEM_NOT_ARMED)
1480 			flags |= NDD_UNARMED;
1481 
1482 		rc = acpi_nfit_add_dimm(acpi_desc, nfit_mem, device_handle);
1483 		if (rc)
1484 			continue;
1485 
1486 		/*
1487 		 * TODO: provide translation for non-NVDIMM_FAMILY_INTEL
1488 		 * devices (i.e. from nd_cmd to acpi_dsm) to standardize the
1489 		 * userspace interface.
1490 		 */
1491 		cmd_mask = 1UL << ND_CMD_CALL;
1492 		if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
1493 			cmd_mask |= nfit_mem->dsm_mask;
1494 
1495 		flush = nfit_mem->nfit_flush ? nfit_mem->nfit_flush->flush
1496 			: NULL;
1497 		nvdimm = nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
1498 				acpi_nfit_dimm_attribute_groups,
1499 				flags, cmd_mask, flush ? flush->hint_count : 0,
1500 				nfit_mem->flush_wpq);
1501 		if (!nvdimm)
1502 			return -ENOMEM;
1503 
1504 		nfit_mem->nvdimm = nvdimm;
1505 		dimm_count++;
1506 
1507 		if ((mem_flags & ACPI_NFIT_MEM_FAILED_MASK) == 0)
1508 			continue;
1509 
1510 		dev_info(acpi_desc->dev, "%s flags:%s%s%s%s\n",
1511 				nvdimm_name(nvdimm),
1512 		  mem_flags & ACPI_NFIT_MEM_SAVE_FAILED ? " save_fail" : "",
1513 		  mem_flags & ACPI_NFIT_MEM_RESTORE_FAILED ? " restore_fail":"",
1514 		  mem_flags & ACPI_NFIT_MEM_FLUSH_FAILED ? " flush_fail" : "",
1515 		  mem_flags & ACPI_NFIT_MEM_NOT_ARMED ? " not_armed" : "");
1516 
1517 	}
1518 
1519 	rc = nvdimm_bus_check_dimm_count(acpi_desc->nvdimm_bus, dimm_count);
1520 	if (rc)
1521 		return rc;
1522 
1523 	/*
1524 	 * Now that dimms are successfully registered, and async registration
1525 	 * is flushed, attempt to enable event notification.
1526 	 */
1527 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
1528 		struct kernfs_node *nfit_kernfs;
1529 
1530 		nvdimm = nfit_mem->nvdimm;
1531 		nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
1532 		if (nfit_kernfs)
1533 			nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,
1534 					"flags");
1535 		sysfs_put(nfit_kernfs);
1536 		if (!nfit_mem->flags_attr)
1537 			dev_warn(acpi_desc->dev, "%s: notifications disabled\n",
1538 					nvdimm_name(nvdimm));
1539 	}
1540 
1541 	return devm_add_action_or_reset(acpi_desc->dev, shutdown_dimm_notify,
1542 			acpi_desc);
1543 }
1544 
1545 static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
1546 {
1547 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
1548 	const u8 *uuid = to_nfit_uuid(NFIT_DEV_BUS);
1549 	struct acpi_device *adev;
1550 	int i;
1551 
1552 	nd_desc->cmd_mask = acpi_desc->bus_cmd_force_en;
1553 	adev = to_acpi_dev(acpi_desc);
1554 	if (!adev)
1555 		return;
1556 
1557 	for (i = ND_CMD_ARS_CAP; i <= ND_CMD_CLEAR_ERROR; i++)
1558 		if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
1559 			set_bit(i, &nd_desc->cmd_mask);
1560 }
1561 
1562 static ssize_t range_index_show(struct device *dev,
1563 		struct device_attribute *attr, char *buf)
1564 {
1565 	struct nd_region *nd_region = to_nd_region(dev);
1566 	struct nfit_spa *nfit_spa = nd_region_provider_data(nd_region);
1567 
1568 	return sprintf(buf, "%d\n", nfit_spa->spa->range_index);
1569 }
1570 static DEVICE_ATTR_RO(range_index);
1571 
1572 static struct attribute *acpi_nfit_region_attributes[] = {
1573 	&dev_attr_range_index.attr,
1574 	NULL,
1575 };
1576 
1577 static struct attribute_group acpi_nfit_region_attribute_group = {
1578 	.name = "nfit",
1579 	.attrs = acpi_nfit_region_attributes,
1580 };
1581 
1582 static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
1583 	&nd_region_attribute_group,
1584 	&nd_mapping_attribute_group,
1585 	&nd_device_attribute_group,
1586 	&nd_numa_attribute_group,
1587 	&acpi_nfit_region_attribute_group,
1588 	NULL,
1589 };
1590 
1591 /* enough info to uniquely specify an interleave set */
1592 struct nfit_set_info {
1593 	struct nfit_set_info_map {
1594 		u64 region_offset;
1595 		u32 serial_number;
1596 		u32 pad;
1597 	} mapping[0];
1598 };
1599 
1600 static size_t sizeof_nfit_set_info(int num_mappings)
1601 {
1602 	return sizeof(struct nfit_set_info)
1603 		+ num_mappings * sizeof(struct nfit_set_info_map);
1604 }
1605 
1606 static int cmp_map_compat(const void *m0, const void *m1)
1607 {
1608 	const struct nfit_set_info_map *map0 = m0;
1609 	const struct nfit_set_info_map *map1 = m1;
1610 
1611 	return memcmp(&map0->region_offset, &map1->region_offset,
1612 			sizeof(u64));
1613 }
1614 
1615 static int cmp_map(const void *m0, const void *m1)
1616 {
1617 	const struct nfit_set_info_map *map0 = m0;
1618 	const struct nfit_set_info_map *map1 = m1;
1619 
1620 	return map0->region_offset - map1->region_offset;
1621 }
1622 
1623 /* Retrieve the nth entry referencing this spa */
1624 static struct acpi_nfit_memory_map *memdev_from_spa(
1625 		struct acpi_nfit_desc *acpi_desc, u16 range_index, int n)
1626 {
1627 	struct nfit_memdev *nfit_memdev;
1628 
1629 	list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list)
1630 		if (nfit_memdev->memdev->range_index == range_index)
1631 			if (n-- == 0)
1632 				return nfit_memdev->memdev;
1633 	return NULL;
1634 }
1635 
1636 static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
1637 		struct nd_region_desc *ndr_desc,
1638 		struct acpi_nfit_system_address *spa)
1639 {
1640 	int i, spa_type = nfit_spa_type(spa);
1641 	struct device *dev = acpi_desc->dev;
1642 	struct nd_interleave_set *nd_set;
1643 	u16 nr = ndr_desc->num_mappings;
1644 	struct nfit_set_info *info;
1645 
1646 	if (spa_type == NFIT_SPA_PM || spa_type == NFIT_SPA_VOLATILE)
1647 		/* pass */;
1648 	else
1649 		return 0;
1650 
1651 	nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
1652 	if (!nd_set)
1653 		return -ENOMEM;
1654 
1655 	info = devm_kzalloc(dev, sizeof_nfit_set_info(nr), GFP_KERNEL);
1656 	if (!info)
1657 		return -ENOMEM;
1658 	for (i = 0; i < nr; i++) {
1659 		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1660 		struct nfit_set_info_map *map = &info->mapping[i];
1661 		struct nvdimm *nvdimm = mapping->nvdimm;
1662 		struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
1663 		struct acpi_nfit_memory_map *memdev = memdev_from_spa(acpi_desc,
1664 				spa->range_index, i);
1665 
1666 		if (!memdev || !nfit_mem->dcr) {
1667 			dev_err(dev, "%s: failed to find DCR\n", __func__);
1668 			return -ENODEV;
1669 		}
1670 
1671 		map->region_offset = memdev->region_offset;
1672 		map->serial_number = nfit_mem->dcr->serial_number;
1673 	}
1674 
1675 	sort(&info->mapping[0], nr, sizeof(struct nfit_set_info_map),
1676 			cmp_map, NULL);
1677 	nd_set->cookie = nd_fletcher64(info, sizeof_nfit_set_info(nr), 0);
1678 
1679 	/* support namespaces created with the wrong sort order */
1680 	sort(&info->mapping[0], nr, sizeof(struct nfit_set_info_map),
1681 			cmp_map_compat, NULL);
1682 	nd_set->altcookie = nd_fletcher64(info, sizeof_nfit_set_info(nr), 0);
1683 
1684 	ndr_desc->nd_set = nd_set;
1685 	devm_kfree(dev, info);
1686 
1687 	return 0;
1688 }
1689 
1690 static u64 to_interleave_offset(u64 offset, struct nfit_blk_mmio *mmio)
1691 {
1692 	struct acpi_nfit_interleave *idt = mmio->idt;
1693 	u32 sub_line_offset, line_index, line_offset;
1694 	u64 line_no, table_skip_count, table_offset;
1695 
1696 	line_no = div_u64_rem(offset, mmio->line_size, &sub_line_offset);
1697 	table_skip_count = div_u64_rem(line_no, mmio->num_lines, &line_index);
1698 	line_offset = idt->line_offset[line_index]
1699 		* mmio->line_size;
1700 	table_offset = table_skip_count * mmio->table_size;
1701 
1702 	return mmio->base_offset + line_offset + table_offset + sub_line_offset;
1703 }
1704 
1705 static u32 read_blk_stat(struct nfit_blk *nfit_blk, unsigned int bw)
1706 {
1707 	struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR];
1708 	u64 offset = nfit_blk->stat_offset + mmio->size * bw;
1709 	const u32 STATUS_MASK = 0x80000037;
1710 
1711 	if (mmio->num_lines)
1712 		offset = to_interleave_offset(offset, mmio);
1713 
1714 	return readl(mmio->addr.base + offset) & STATUS_MASK;
1715 }
1716 
1717 static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
1718 		resource_size_t dpa, unsigned int len, unsigned int write)
1719 {
1720 	u64 cmd, offset;
1721 	struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR];
1722 
1723 	enum {
1724 		BCW_OFFSET_MASK = (1ULL << 48)-1,
1725 		BCW_LEN_SHIFT = 48,
1726 		BCW_LEN_MASK = (1ULL << 8) - 1,
1727 		BCW_CMD_SHIFT = 56,
1728 	};
1729 
1730 	cmd = (dpa >> L1_CACHE_SHIFT) & BCW_OFFSET_MASK;
1731 	len = len >> L1_CACHE_SHIFT;
1732 	cmd |= ((u64) len & BCW_LEN_MASK) << BCW_LEN_SHIFT;
1733 	cmd |= ((u64) write) << BCW_CMD_SHIFT;
1734 
1735 	offset = nfit_blk->cmd_offset + mmio->size * bw;
1736 	if (mmio->num_lines)
1737 		offset = to_interleave_offset(offset, mmio);
1738 
1739 	writeq(cmd, mmio->addr.base + offset);
1740 	nvdimm_flush(nfit_blk->nd_region);
1741 
1742 	if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
1743 		readq(mmio->addr.base + offset);
1744 }
1745 
1746 static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
1747 		resource_size_t dpa, void *iobuf, size_t len, int rw,
1748 		unsigned int lane)
1749 {
1750 	struct nfit_blk_mmio *mmio = &nfit_blk->mmio[BDW];
1751 	unsigned int copied = 0;
1752 	u64 base_offset;
1753 	int rc;
1754 
1755 	base_offset = nfit_blk->bdw_offset + dpa % L1_CACHE_BYTES
1756 		+ lane * mmio->size;
1757 	write_blk_ctl(nfit_blk, lane, dpa, len, rw);
1758 	while (len) {
1759 		unsigned int c;
1760 		u64 offset;
1761 
1762 		if (mmio->num_lines) {
1763 			u32 line_offset;
1764 
1765 			offset = to_interleave_offset(base_offset + copied,
1766 					mmio);
1767 			div_u64_rem(offset, mmio->line_size, &line_offset);
1768 			c = min_t(size_t, len, mmio->line_size - line_offset);
1769 		} else {
1770 			offset = base_offset + nfit_blk->bdw_offset;
1771 			c = len;
1772 		}
1773 
1774 		if (rw)
1775 			memcpy_to_pmem(mmio->addr.aperture + offset,
1776 					iobuf + copied, c);
1777 		else {
1778 			if (nfit_blk->dimm_flags & NFIT_BLK_READ_FLUSH)
1779 				mmio_flush_range((void __force *)
1780 					mmio->addr.aperture + offset, c);
1781 
1782 			memcpy_from_pmem(iobuf + copied,
1783 					mmio->addr.aperture + offset, c);
1784 		}
1785 
1786 		copied += c;
1787 		len -= c;
1788 	}
1789 
1790 	if (rw)
1791 		nvdimm_flush(nfit_blk->nd_region);
1792 
1793 	rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0;
1794 	return rc;
1795 }
1796 
1797 static int acpi_nfit_blk_region_do_io(struct nd_blk_region *ndbr,
1798 		resource_size_t dpa, void *iobuf, u64 len, int rw)
1799 {
1800 	struct nfit_blk *nfit_blk = nd_blk_region_provider_data(ndbr);
1801 	struct nfit_blk_mmio *mmio = &nfit_blk->mmio[BDW];
1802 	struct nd_region *nd_region = nfit_blk->nd_region;
1803 	unsigned int lane, copied = 0;
1804 	int rc = 0;
1805 
1806 	lane = nd_region_acquire_lane(nd_region);
1807 	while (len) {
1808 		u64 c = min(len, mmio->size);
1809 
1810 		rc = acpi_nfit_blk_single_io(nfit_blk, dpa + copied,
1811 				iobuf + copied, c, rw, lane);
1812 		if (rc)
1813 			break;
1814 
1815 		copied += c;
1816 		len -= c;
1817 	}
1818 	nd_region_release_lane(nd_region, lane);
1819 
1820 	return rc;
1821 }
1822 
1823 static int nfit_blk_init_interleave(struct nfit_blk_mmio *mmio,
1824 		struct acpi_nfit_interleave *idt, u16 interleave_ways)
1825 {
1826 	if (idt) {
1827 		mmio->num_lines = idt->line_count;
1828 		mmio->line_size = idt->line_size;
1829 		if (interleave_ways == 0)
1830 			return -ENXIO;
1831 		mmio->table_size = mmio->num_lines * interleave_ways
1832 			* mmio->line_size;
1833 	}
1834 
1835 	return 0;
1836 }
1837 
1838 static int acpi_nfit_blk_get_flags(struct nvdimm_bus_descriptor *nd_desc,
1839 		struct nvdimm *nvdimm, struct nfit_blk *nfit_blk)
1840 {
1841 	struct nd_cmd_dimm_flags flags;
1842 	int rc;
1843 
1844 	memset(&flags, 0, sizeof(flags));
1845 	rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_DIMM_FLAGS, &flags,
1846 			sizeof(flags), NULL);
1847 
1848 	if (rc >= 0 && flags.status == 0)
1849 		nfit_blk->dimm_flags = flags.flags;
1850 	else if (rc == -ENOTTY) {
1851 		/* fall back to a conservative default */
1852 		nfit_blk->dimm_flags = NFIT_BLK_DCR_LATCH | NFIT_BLK_READ_FLUSH;
1853 		rc = 0;
1854 	} else
1855 		rc = -ENXIO;
1856 
1857 	return rc;
1858 }
1859 
1860 static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
1861 		struct device *dev)
1862 {
1863 	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
1864 	struct nd_blk_region *ndbr = to_nd_blk_region(dev);
1865 	struct nfit_blk_mmio *mmio;
1866 	struct nfit_blk *nfit_blk;
1867 	struct nfit_mem *nfit_mem;
1868 	struct nvdimm *nvdimm;
1869 	int rc;
1870 
1871 	nvdimm = nd_blk_region_to_dimm(ndbr);
1872 	nfit_mem = nvdimm_provider_data(nvdimm);
1873 	if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) {
1874 		dev_dbg(dev, "%s: missing%s%s%s\n", __func__,
1875 				nfit_mem ? "" : " nfit_mem",
1876 				(nfit_mem && nfit_mem->dcr) ? "" : " dcr",
1877 				(nfit_mem && nfit_mem->bdw) ? "" : " bdw");
1878 		return -ENXIO;
1879 	}
1880 
1881 	nfit_blk = devm_kzalloc(dev, sizeof(*nfit_blk), GFP_KERNEL);
1882 	if (!nfit_blk)
1883 		return -ENOMEM;
1884 	nd_blk_region_set_provider_data(ndbr, nfit_blk);
1885 	nfit_blk->nd_region = to_nd_region(dev);
1886 
1887 	/* map block aperture memory */
1888 	nfit_blk->bdw_offset = nfit_mem->bdw->offset;
1889 	mmio = &nfit_blk->mmio[BDW];
1890 	mmio->addr.base = devm_nvdimm_memremap(dev, nfit_mem->spa_bdw->address,
1891                         nfit_mem->spa_bdw->length, ARCH_MEMREMAP_PMEM);
1892 	if (!mmio->addr.base) {
1893 		dev_dbg(dev, "%s: %s failed to map bdw\n", __func__,
1894 				nvdimm_name(nvdimm));
1895 		return -ENOMEM;
1896 	}
1897 	mmio->size = nfit_mem->bdw->size;
1898 	mmio->base_offset = nfit_mem->memdev_bdw->region_offset;
1899 	mmio->idt = nfit_mem->idt_bdw;
1900 	mmio->spa = nfit_mem->spa_bdw;
1901 	rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_bdw,
1902 			nfit_mem->memdev_bdw->interleave_ways);
1903 	if (rc) {
1904 		dev_dbg(dev, "%s: %s failed to init bdw interleave\n",
1905 				__func__, nvdimm_name(nvdimm));
1906 		return rc;
1907 	}
1908 
1909 	/* map block control memory */
1910 	nfit_blk->cmd_offset = nfit_mem->dcr->command_offset;
1911 	nfit_blk->stat_offset = nfit_mem->dcr->status_offset;
1912 	mmio = &nfit_blk->mmio[DCR];
1913 	mmio->addr.base = devm_nvdimm_ioremap(dev, nfit_mem->spa_dcr->address,
1914 			nfit_mem->spa_dcr->length);
1915 	if (!mmio->addr.base) {
1916 		dev_dbg(dev, "%s: %s failed to map dcr\n", __func__,
1917 				nvdimm_name(nvdimm));
1918 		return -ENOMEM;
1919 	}
1920 	mmio->size = nfit_mem->dcr->window_size;
1921 	mmio->base_offset = nfit_mem->memdev_dcr->region_offset;
1922 	mmio->idt = nfit_mem->idt_dcr;
1923 	mmio->spa = nfit_mem->spa_dcr;
1924 	rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_dcr,
1925 			nfit_mem->memdev_dcr->interleave_ways);
1926 	if (rc) {
1927 		dev_dbg(dev, "%s: %s failed to init dcr interleave\n",
1928 				__func__, nvdimm_name(nvdimm));
1929 		return rc;
1930 	}
1931 
1932 	rc = acpi_nfit_blk_get_flags(nd_desc, nvdimm, nfit_blk);
1933 	if (rc < 0) {
1934 		dev_dbg(dev, "%s: %s failed get DIMM flags\n",
1935 				__func__, nvdimm_name(nvdimm));
1936 		return rc;
1937 	}
1938 
1939 	if (nvdimm_has_flush(nfit_blk->nd_region) < 0)
1940 		dev_warn(dev, "unable to guarantee persistence of writes\n");
1941 
1942 	if (mmio->line_size == 0)
1943 		return 0;
1944 
1945 	if ((u32) nfit_blk->cmd_offset % mmio->line_size
1946 			+ 8 > mmio->line_size) {
1947 		dev_dbg(dev, "cmd_offset crosses interleave boundary\n");
1948 		return -ENXIO;
1949 	} else if ((u32) nfit_blk->stat_offset % mmio->line_size
1950 			+ 8 > mmio->line_size) {
1951 		dev_dbg(dev, "stat_offset crosses interleave boundary\n");
1952 		return -ENXIO;
1953 	}
1954 
1955 	return 0;
1956 }
1957 
1958 static int ars_get_cap(struct acpi_nfit_desc *acpi_desc,
1959 		struct nd_cmd_ars_cap *cmd, struct nfit_spa *nfit_spa)
1960 {
1961 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
1962 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
1963 	int cmd_rc, rc;
1964 
1965 	cmd->address = spa->address;
1966 	cmd->length = spa->length;
1967 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, cmd,
1968 			sizeof(*cmd), &cmd_rc);
1969 	if (rc < 0)
1970 		return rc;
1971 	return cmd_rc;
1972 }
1973 
1974 static int ars_start(struct acpi_nfit_desc *acpi_desc, struct nfit_spa *nfit_spa)
1975 {
1976 	int rc;
1977 	int cmd_rc;
1978 	struct nd_cmd_ars_start ars_start;
1979 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
1980 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
1981 
1982 	memset(&ars_start, 0, sizeof(ars_start));
1983 	ars_start.address = spa->address;
1984 	ars_start.length = spa->length;
1985 	if (nfit_spa_type(spa) == NFIT_SPA_PM)
1986 		ars_start.type = ND_ARS_PERSISTENT;
1987 	else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE)
1988 		ars_start.type = ND_ARS_VOLATILE;
1989 	else
1990 		return -ENOTTY;
1991 
1992 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
1993 			sizeof(ars_start), &cmd_rc);
1994 
1995 	if (rc < 0)
1996 		return rc;
1997 	return cmd_rc;
1998 }
1999 
2000 static int ars_continue(struct acpi_nfit_desc *acpi_desc)
2001 {
2002 	int rc, cmd_rc;
2003 	struct nd_cmd_ars_start ars_start;
2004 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
2005 	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
2006 
2007 	memset(&ars_start, 0, sizeof(ars_start));
2008 	ars_start.address = ars_status->restart_address;
2009 	ars_start.length = ars_status->restart_length;
2010 	ars_start.type = ars_status->type;
2011 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
2012 			sizeof(ars_start), &cmd_rc);
2013 	if (rc < 0)
2014 		return rc;
2015 	return cmd_rc;
2016 }
2017 
2018 static int ars_get_status(struct acpi_nfit_desc *acpi_desc)
2019 {
2020 	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
2021 	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
2022 	int rc, cmd_rc;
2023 
2024 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, ars_status,
2025 			acpi_desc->ars_status_size, &cmd_rc);
2026 	if (rc < 0)
2027 		return rc;
2028 	return cmd_rc;
2029 }
2030 
2031 static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc,
2032 		struct nd_cmd_ars_status *ars_status)
2033 {
2034 	struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
2035 	int rc;
2036 	u32 i;
2037 
2038 	/*
2039 	 * First record starts at 44 byte offset from the start of the
2040 	 * payload.
2041 	 */
2042 	if (ars_status->out_length < 44)
2043 		return 0;
2044 	for (i = 0; i < ars_status->num_records; i++) {
2045 		/* only process full records */
2046 		if (ars_status->out_length
2047 				< 44 + sizeof(struct nd_ars_record) * (i + 1))
2048 			break;
2049 		rc = nvdimm_bus_add_poison(nvdimm_bus,
2050 				ars_status->records[i].err_address,
2051 				ars_status->records[i].length);
2052 		if (rc)
2053 			return rc;
2054 	}
2055 	if (i < ars_status->num_records)
2056 		dev_warn(acpi_desc->dev, "detected truncated ars results\n");
2057 
2058 	return 0;
2059 }
2060 
2061 static void acpi_nfit_remove_resource(void *data)
2062 {
2063 	struct resource *res = data;
2064 
2065 	remove_resource(res);
2066 }
2067 
2068 static int acpi_nfit_insert_resource(struct acpi_nfit_desc *acpi_desc,
2069 		struct nd_region_desc *ndr_desc)
2070 {
2071 	struct resource *res, *nd_res = ndr_desc->res;
2072 	int is_pmem, ret;
2073 
2074 	/* No operation if the region is already registered as PMEM */
2075 	is_pmem = region_intersects(nd_res->start, resource_size(nd_res),
2076 				IORESOURCE_MEM, IORES_DESC_PERSISTENT_MEMORY);
2077 	if (is_pmem == REGION_INTERSECTS)
2078 		return 0;
2079 
2080 	res = devm_kzalloc(acpi_desc->dev, sizeof(*res), GFP_KERNEL);
2081 	if (!res)
2082 		return -ENOMEM;
2083 
2084 	res->name = "Persistent Memory";
2085 	res->start = nd_res->start;
2086 	res->end = nd_res->end;
2087 	res->flags = IORESOURCE_MEM;
2088 	res->desc = IORES_DESC_PERSISTENT_MEMORY;
2089 
2090 	ret = insert_resource(&iomem_resource, res);
2091 	if (ret)
2092 		return ret;
2093 
2094 	ret = devm_add_action_or_reset(acpi_desc->dev,
2095 					acpi_nfit_remove_resource,
2096 					res);
2097 	if (ret)
2098 		return ret;
2099 
2100 	return 0;
2101 }
2102 
2103 static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
2104 		struct nd_mapping_desc *mapping, struct nd_region_desc *ndr_desc,
2105 		struct acpi_nfit_memory_map *memdev,
2106 		struct nfit_spa *nfit_spa)
2107 {
2108 	struct nvdimm *nvdimm = acpi_nfit_dimm_by_handle(acpi_desc,
2109 			memdev->device_handle);
2110 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
2111 	struct nd_blk_region_desc *ndbr_desc;
2112 	struct nfit_mem *nfit_mem;
2113 	int blk_valid = 0;
2114 
2115 	if (!nvdimm) {
2116 		dev_err(acpi_desc->dev, "spa%d dimm: %#x not found\n",
2117 				spa->range_index, memdev->device_handle);
2118 		return -ENODEV;
2119 	}
2120 
2121 	mapping->nvdimm = nvdimm;
2122 	switch (nfit_spa_type(spa)) {
2123 	case NFIT_SPA_PM:
2124 	case NFIT_SPA_VOLATILE:
2125 		mapping->start = memdev->address;
2126 		mapping->size = memdev->region_size;
2127 		break;
2128 	case NFIT_SPA_DCR:
2129 		nfit_mem = nvdimm_provider_data(nvdimm);
2130 		if (!nfit_mem || !nfit_mem->bdw) {
2131 			dev_dbg(acpi_desc->dev, "spa%d %s missing bdw\n",
2132 					spa->range_index, nvdimm_name(nvdimm));
2133 		} else {
2134 			mapping->size = nfit_mem->bdw->capacity;
2135 			mapping->start = nfit_mem->bdw->start_address;
2136 			ndr_desc->num_lanes = nfit_mem->bdw->windows;
2137 			blk_valid = 1;
2138 		}
2139 
2140 		ndr_desc->mapping = mapping;
2141 		ndr_desc->num_mappings = blk_valid;
2142 		ndbr_desc = to_blk_region_desc(ndr_desc);
2143 		ndbr_desc->enable = acpi_nfit_blk_region_enable;
2144 		ndbr_desc->do_io = acpi_desc->blk_do_io;
2145 		nfit_spa->nd_region = nvdimm_blk_region_create(acpi_desc->nvdimm_bus,
2146 				ndr_desc);
2147 		if (!nfit_spa->nd_region)
2148 			return -ENOMEM;
2149 		break;
2150 	}
2151 
2152 	return 0;
2153 }
2154 
2155 static bool nfit_spa_is_virtual(struct acpi_nfit_system_address *spa)
2156 {
2157 	return (nfit_spa_type(spa) == NFIT_SPA_VDISK ||
2158 		nfit_spa_type(spa) == NFIT_SPA_VCD   ||
2159 		nfit_spa_type(spa) == NFIT_SPA_PDISK ||
2160 		nfit_spa_type(spa) == NFIT_SPA_PCD);
2161 }
2162 
2163 static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
2164 		struct nfit_spa *nfit_spa)
2165 {
2166 	static struct nd_mapping_desc mappings[ND_MAX_MAPPINGS];
2167 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
2168 	struct nd_blk_region_desc ndbr_desc;
2169 	struct nd_region_desc *ndr_desc;
2170 	struct nfit_memdev *nfit_memdev;
2171 	struct nvdimm_bus *nvdimm_bus;
2172 	struct resource res;
2173 	int count = 0, rc;
2174 
2175 	if (nfit_spa->nd_region)
2176 		return 0;
2177 
2178 	if (spa->range_index == 0 && !nfit_spa_is_virtual(spa)) {
2179 		dev_dbg(acpi_desc->dev, "%s: detected invalid spa index\n",
2180 				__func__);
2181 		return 0;
2182 	}
2183 
2184 	memset(&res, 0, sizeof(res));
2185 	memset(&mappings, 0, sizeof(mappings));
2186 	memset(&ndbr_desc, 0, sizeof(ndbr_desc));
2187 	res.start = spa->address;
2188 	res.end = res.start + spa->length - 1;
2189 	ndr_desc = &ndbr_desc.ndr_desc;
2190 	ndr_desc->res = &res;
2191 	ndr_desc->provider_data = nfit_spa;
2192 	ndr_desc->attr_groups = acpi_nfit_region_attribute_groups;
2193 	if (spa->flags & ACPI_NFIT_PROXIMITY_VALID)
2194 		ndr_desc->numa_node = acpi_map_pxm_to_online_node(
2195 						spa->proximity_domain);
2196 	else
2197 		ndr_desc->numa_node = NUMA_NO_NODE;
2198 
2199 	list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
2200 		struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev;
2201 		struct nd_mapping_desc *mapping;
2202 
2203 		if (memdev->range_index != spa->range_index)
2204 			continue;
2205 		if (count >= ND_MAX_MAPPINGS) {
2206 			dev_err(acpi_desc->dev, "spa%d exceeds max mappings %d\n",
2207 					spa->range_index, ND_MAX_MAPPINGS);
2208 			return -ENXIO;
2209 		}
2210 		mapping = &mappings[count++];
2211 		rc = acpi_nfit_init_mapping(acpi_desc, mapping, ndr_desc,
2212 				memdev, nfit_spa);
2213 		if (rc)
2214 			goto out;
2215 	}
2216 
2217 	ndr_desc->mapping = mappings;
2218 	ndr_desc->num_mappings = count;
2219 	rc = acpi_nfit_init_interleave_set(acpi_desc, ndr_desc, spa);
2220 	if (rc)
2221 		goto out;
2222 
2223 	nvdimm_bus = acpi_desc->nvdimm_bus;
2224 	if (nfit_spa_type(spa) == NFIT_SPA_PM) {
2225 		rc = acpi_nfit_insert_resource(acpi_desc, ndr_desc);
2226 		if (rc) {
2227 			dev_warn(acpi_desc->dev,
2228 				"failed to insert pmem resource to iomem: %d\n",
2229 				rc);
2230 			goto out;
2231 		}
2232 
2233 		nfit_spa->nd_region = nvdimm_pmem_region_create(nvdimm_bus,
2234 				ndr_desc);
2235 		if (!nfit_spa->nd_region)
2236 			rc = -ENOMEM;
2237 	} else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE) {
2238 		nfit_spa->nd_region = nvdimm_volatile_region_create(nvdimm_bus,
2239 				ndr_desc);
2240 		if (!nfit_spa->nd_region)
2241 			rc = -ENOMEM;
2242 	} else if (nfit_spa_is_virtual(spa)) {
2243 		nfit_spa->nd_region = nvdimm_pmem_region_create(nvdimm_bus,
2244 				ndr_desc);
2245 		if (!nfit_spa->nd_region)
2246 			rc = -ENOMEM;
2247 	}
2248 
2249  out:
2250 	if (rc)
2251 		dev_err(acpi_desc->dev, "failed to register spa range %d\n",
2252 				nfit_spa->spa->range_index);
2253 	return rc;
2254 }
2255 
2256 static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc,
2257 		u32 max_ars)
2258 {
2259 	struct device *dev = acpi_desc->dev;
2260 	struct nd_cmd_ars_status *ars_status;
2261 
2262 	if (acpi_desc->ars_status && acpi_desc->ars_status_size >= max_ars) {
2263 		memset(acpi_desc->ars_status, 0, acpi_desc->ars_status_size);
2264 		return 0;
2265 	}
2266 
2267 	if (acpi_desc->ars_status)
2268 		devm_kfree(dev, acpi_desc->ars_status);
2269 	acpi_desc->ars_status = NULL;
2270 	ars_status = devm_kzalloc(dev, max_ars, GFP_KERNEL);
2271 	if (!ars_status)
2272 		return -ENOMEM;
2273 	acpi_desc->ars_status = ars_status;
2274 	acpi_desc->ars_status_size = max_ars;
2275 	return 0;
2276 }
2277 
2278 static int acpi_nfit_query_poison(struct acpi_nfit_desc *acpi_desc,
2279 		struct nfit_spa *nfit_spa)
2280 {
2281 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
2282 	int rc;
2283 
2284 	if (!nfit_spa->max_ars) {
2285 		struct nd_cmd_ars_cap ars_cap;
2286 
2287 		memset(&ars_cap, 0, sizeof(ars_cap));
2288 		rc = ars_get_cap(acpi_desc, &ars_cap, nfit_spa);
2289 		if (rc < 0)
2290 			return rc;
2291 		nfit_spa->max_ars = ars_cap.max_ars_out;
2292 		nfit_spa->clear_err_unit = ars_cap.clear_err_unit;
2293 		/* check that the supported scrub types match the spa type */
2294 		if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE &&
2295 				((ars_cap.status >> 16) & ND_ARS_VOLATILE) == 0)
2296 			return -ENOTTY;
2297 		else if (nfit_spa_type(spa) == NFIT_SPA_PM &&
2298 				((ars_cap.status >> 16) & ND_ARS_PERSISTENT) == 0)
2299 			return -ENOTTY;
2300 	}
2301 
2302 	if (ars_status_alloc(acpi_desc, nfit_spa->max_ars))
2303 		return -ENOMEM;
2304 
2305 	rc = ars_get_status(acpi_desc);
2306 	if (rc < 0 && rc != -ENOSPC)
2307 		return rc;
2308 
2309 	if (ars_status_process_records(acpi_desc, acpi_desc->ars_status))
2310 		return -ENOMEM;
2311 
2312 	return 0;
2313 }
2314 
2315 static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc,
2316 		struct nfit_spa *nfit_spa)
2317 {
2318 	struct acpi_nfit_system_address *spa = nfit_spa->spa;
2319 	unsigned int overflow_retry = scrub_overflow_abort;
2320 	u64 init_ars_start = 0, init_ars_len = 0;
2321 	struct device *dev = acpi_desc->dev;
2322 	unsigned int tmo = scrub_timeout;
2323 	int rc;
2324 
2325 	if (!nfit_spa->ars_required || !nfit_spa->nd_region)
2326 		return;
2327 
2328 	rc = ars_start(acpi_desc, nfit_spa);
2329 	/*
2330 	 * If we timed out the initial scan we'll still be busy here,
2331 	 * and will wait another timeout before giving up permanently.
2332 	 */
2333 	if (rc < 0 && rc != -EBUSY)
2334 		return;
2335 
2336 	do {
2337 		u64 ars_start, ars_len;
2338 
2339 		if (acpi_desc->cancel)
2340 			break;
2341 		rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
2342 		if (rc == -ENOTTY)
2343 			break;
2344 		if (rc == -EBUSY && !tmo) {
2345 			dev_warn(dev, "range %d ars timeout, aborting\n",
2346 					spa->range_index);
2347 			break;
2348 		}
2349 
2350 		if (rc == -EBUSY) {
2351 			/*
2352 			 * Note, entries may be appended to the list
2353 			 * while the lock is dropped, but the workqueue
2354 			 * being active prevents entries being deleted /
2355 			 * freed.
2356 			 */
2357 			mutex_unlock(&acpi_desc->init_mutex);
2358 			ssleep(1);
2359 			tmo--;
2360 			mutex_lock(&acpi_desc->init_mutex);
2361 			continue;
2362 		}
2363 
2364 		/* we got some results, but there are more pending... */
2365 		if (rc == -ENOSPC && overflow_retry--) {
2366 			if (!init_ars_len) {
2367 				init_ars_len = acpi_desc->ars_status->length;
2368 				init_ars_start = acpi_desc->ars_status->address;
2369 			}
2370 			rc = ars_continue(acpi_desc);
2371 		}
2372 
2373 		if (rc < 0) {
2374 			dev_warn(dev, "range %d ars continuation failed\n",
2375 					spa->range_index);
2376 			break;
2377 		}
2378 
2379 		if (init_ars_len) {
2380 			ars_start = init_ars_start;
2381 			ars_len = init_ars_len;
2382 		} else {
2383 			ars_start = acpi_desc->ars_status->address;
2384 			ars_len = acpi_desc->ars_status->length;
2385 		}
2386 		dev_dbg(dev, "spa range: %d ars from %#llx + %#llx complete\n",
2387 				spa->range_index, ars_start, ars_len);
2388 		/* notify the region about new poison entries */
2389 		nvdimm_region_notify(nfit_spa->nd_region,
2390 				NVDIMM_REVALIDATE_POISON);
2391 		break;
2392 	} while (1);
2393 }
2394 
2395 static void acpi_nfit_scrub(struct work_struct *work)
2396 {
2397 	struct device *dev;
2398 	u64 init_scrub_length = 0;
2399 	struct nfit_spa *nfit_spa;
2400 	u64 init_scrub_address = 0;
2401 	bool init_ars_done = false;
2402 	struct acpi_nfit_desc *acpi_desc;
2403 	unsigned int tmo = scrub_timeout;
2404 	unsigned int overflow_retry = scrub_overflow_abort;
2405 
2406 	acpi_desc = container_of(work, typeof(*acpi_desc), work);
2407 	dev = acpi_desc->dev;
2408 
2409 	/*
2410 	 * We scrub in 2 phases.  The first phase waits for any platform
2411 	 * firmware initiated scrubs to complete and then we go search for the
2412 	 * affected spa regions to mark them scanned.  In the second phase we
2413 	 * initiate a directed scrub for every range that was not scrubbed in
2414 	 * phase 1. If we're called for a 'rescan', we harmlessly pass through
2415 	 * the first phase, but really only care about running phase 2, where
2416 	 * regions can be notified of new poison.
2417 	 */
2418 
2419 	/* process platform firmware initiated scrubs */
2420  retry:
2421 	mutex_lock(&acpi_desc->init_mutex);
2422 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
2423 		struct nd_cmd_ars_status *ars_status;
2424 		struct acpi_nfit_system_address *spa;
2425 		u64 ars_start, ars_len;
2426 		int rc;
2427 
2428 		if (acpi_desc->cancel)
2429 			break;
2430 
2431 		if (nfit_spa->nd_region)
2432 			continue;
2433 
2434 		if (init_ars_done) {
2435 			/*
2436 			 * No need to re-query, we're now just
2437 			 * reconciling all the ranges covered by the
2438 			 * initial scrub
2439 			 */
2440 			rc = 0;
2441 		} else
2442 			rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
2443 
2444 		if (rc == -ENOTTY) {
2445 			/* no ars capability, just register spa and move on */
2446 			acpi_nfit_register_region(acpi_desc, nfit_spa);
2447 			continue;
2448 		}
2449 
2450 		if (rc == -EBUSY && !tmo) {
2451 			/* fallthrough to directed scrub in phase 2 */
2452 			dev_warn(dev, "timeout awaiting ars results, continuing...\n");
2453 			break;
2454 		} else if (rc == -EBUSY) {
2455 			mutex_unlock(&acpi_desc->init_mutex);
2456 			ssleep(1);
2457 			tmo--;
2458 			goto retry;
2459 		}
2460 
2461 		/* we got some results, but there are more pending... */
2462 		if (rc == -ENOSPC && overflow_retry--) {
2463 			ars_status = acpi_desc->ars_status;
2464 			/*
2465 			 * Record the original scrub range, so that we
2466 			 * can recall all the ranges impacted by the
2467 			 * initial scrub.
2468 			 */
2469 			if (!init_scrub_length) {
2470 				init_scrub_length = ars_status->length;
2471 				init_scrub_address = ars_status->address;
2472 			}
2473 			rc = ars_continue(acpi_desc);
2474 			if (rc == 0) {
2475 				mutex_unlock(&acpi_desc->init_mutex);
2476 				goto retry;
2477 			}
2478 		}
2479 
2480 		if (rc < 0) {
2481 			/*
2482 			 * Initial scrub failed, we'll give it one more
2483 			 * try below...
2484 			 */
2485 			break;
2486 		}
2487 
2488 		/* We got some final results, record completed ranges */
2489 		ars_status = acpi_desc->ars_status;
2490 		if (init_scrub_length) {
2491 			ars_start = init_scrub_address;
2492 			ars_len = ars_start + init_scrub_length;
2493 		} else {
2494 			ars_start = ars_status->address;
2495 			ars_len = ars_status->length;
2496 		}
2497 		spa = nfit_spa->spa;
2498 
2499 		if (!init_ars_done) {
2500 			init_ars_done = true;
2501 			dev_dbg(dev, "init scrub %#llx + %#llx complete\n",
2502 					ars_start, ars_len);
2503 		}
2504 		if (ars_start <= spa->address && ars_start + ars_len
2505 				>= spa->address + spa->length)
2506 			acpi_nfit_register_region(acpi_desc, nfit_spa);
2507 	}
2508 
2509 	/*
2510 	 * For all the ranges not covered by an initial scrub we still
2511 	 * want to see if there are errors, but it's ok to discover them
2512 	 * asynchronously.
2513 	 */
2514 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
2515 		/*
2516 		 * Flag all the ranges that still need scrubbing, but
2517 		 * register them now to make data available.
2518 		 */
2519 		if (!nfit_spa->nd_region) {
2520 			nfit_spa->ars_required = 1;
2521 			acpi_nfit_register_region(acpi_desc, nfit_spa);
2522 		}
2523 	}
2524 
2525 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
2526 		acpi_nfit_async_scrub(acpi_desc, nfit_spa);
2527 	acpi_desc->scrub_count++;
2528 	if (acpi_desc->scrub_count_state)
2529 		sysfs_notify_dirent(acpi_desc->scrub_count_state);
2530 	mutex_unlock(&acpi_desc->init_mutex);
2531 }
2532 
2533 static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
2534 {
2535 	struct nfit_spa *nfit_spa;
2536 	int rc;
2537 
2538 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
2539 		if (nfit_spa_type(nfit_spa->spa) == NFIT_SPA_DCR) {
2540 			/* BLK regions don't need to wait for ars results */
2541 			rc = acpi_nfit_register_region(acpi_desc, nfit_spa);
2542 			if (rc)
2543 				return rc;
2544 		}
2545 
2546 	queue_work(nfit_wq, &acpi_desc->work);
2547 	return 0;
2548 }
2549 
2550 static int acpi_nfit_check_deletions(struct acpi_nfit_desc *acpi_desc,
2551 		struct nfit_table_prev *prev)
2552 {
2553 	struct device *dev = acpi_desc->dev;
2554 
2555 	if (!list_empty(&prev->spas) ||
2556 			!list_empty(&prev->memdevs) ||
2557 			!list_empty(&prev->dcrs) ||
2558 			!list_empty(&prev->bdws) ||
2559 			!list_empty(&prev->idts) ||
2560 			!list_empty(&prev->flushes)) {
2561 		dev_err(dev, "new nfit deletes entries (unsupported)\n");
2562 		return -ENXIO;
2563 	}
2564 	return 0;
2565 }
2566 
2567 static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc)
2568 {
2569 	struct device *dev = acpi_desc->dev;
2570 	struct kernfs_node *nfit;
2571 	struct device *bus_dev;
2572 
2573 	if (!ars_supported(acpi_desc->nvdimm_bus))
2574 		return 0;
2575 
2576 	bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
2577 	nfit = sysfs_get_dirent(bus_dev->kobj.sd, "nfit");
2578 	if (!nfit) {
2579 		dev_err(dev, "sysfs_get_dirent 'nfit' failed\n");
2580 		return -ENODEV;
2581 	}
2582 	acpi_desc->scrub_count_state = sysfs_get_dirent(nfit, "scrub");
2583 	sysfs_put(nfit);
2584 	if (!acpi_desc->scrub_count_state) {
2585 		dev_err(dev, "sysfs_get_dirent 'scrub' failed\n");
2586 		return -ENODEV;
2587 	}
2588 
2589 	return 0;
2590 }
2591 
2592 static void acpi_nfit_destruct(void *data)
2593 {
2594 	struct acpi_nfit_desc *acpi_desc = data;
2595 	struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
2596 
2597 	/*
2598 	 * Destruct under acpi_desc_lock so that nfit_handle_mce does not
2599 	 * race teardown
2600 	 */
2601 	mutex_lock(&acpi_desc_lock);
2602 	acpi_desc->cancel = 1;
2603 	/*
2604 	 * Bounce the nvdimm bus lock to make sure any in-flight
2605 	 * acpi_nfit_ars_rescan() submissions have had a chance to
2606 	 * either submit or see ->cancel set.
2607 	 */
2608 	device_lock(bus_dev);
2609 	device_unlock(bus_dev);
2610 
2611 	flush_workqueue(nfit_wq);
2612 	if (acpi_desc->scrub_count_state)
2613 		sysfs_put(acpi_desc->scrub_count_state);
2614 	nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
2615 	acpi_desc->nvdimm_bus = NULL;
2616 	list_del(&acpi_desc->list);
2617 	mutex_unlock(&acpi_desc_lock);
2618 }
2619 
2620 int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz)
2621 {
2622 	struct device *dev = acpi_desc->dev;
2623 	struct nfit_table_prev prev;
2624 	const void *end;
2625 	int rc;
2626 
2627 	if (!acpi_desc->nvdimm_bus) {
2628 		acpi_nfit_init_dsms(acpi_desc);
2629 
2630 		acpi_desc->nvdimm_bus = nvdimm_bus_register(dev,
2631 				&acpi_desc->nd_desc);
2632 		if (!acpi_desc->nvdimm_bus)
2633 			return -ENOMEM;
2634 
2635 		rc = devm_add_action_or_reset(dev, acpi_nfit_destruct,
2636 				acpi_desc);
2637 		if (rc)
2638 			return rc;
2639 
2640 		rc = acpi_nfit_desc_init_scrub_attr(acpi_desc);
2641 		if (rc)
2642 			return rc;
2643 
2644 		/* register this acpi_desc for mce notifications */
2645 		mutex_lock(&acpi_desc_lock);
2646 		list_add_tail(&acpi_desc->list, &acpi_descs);
2647 		mutex_unlock(&acpi_desc_lock);
2648 	}
2649 
2650 	mutex_lock(&acpi_desc->init_mutex);
2651 
2652 	INIT_LIST_HEAD(&prev.spas);
2653 	INIT_LIST_HEAD(&prev.memdevs);
2654 	INIT_LIST_HEAD(&prev.dcrs);
2655 	INIT_LIST_HEAD(&prev.bdws);
2656 	INIT_LIST_HEAD(&prev.idts);
2657 	INIT_LIST_HEAD(&prev.flushes);
2658 
2659 	list_cut_position(&prev.spas, &acpi_desc->spas,
2660 				acpi_desc->spas.prev);
2661 	list_cut_position(&prev.memdevs, &acpi_desc->memdevs,
2662 				acpi_desc->memdevs.prev);
2663 	list_cut_position(&prev.dcrs, &acpi_desc->dcrs,
2664 				acpi_desc->dcrs.prev);
2665 	list_cut_position(&prev.bdws, &acpi_desc->bdws,
2666 				acpi_desc->bdws.prev);
2667 	list_cut_position(&prev.idts, &acpi_desc->idts,
2668 				acpi_desc->idts.prev);
2669 	list_cut_position(&prev.flushes, &acpi_desc->flushes,
2670 				acpi_desc->flushes.prev);
2671 
2672 	end = data + sz;
2673 	while (!IS_ERR_OR_NULL(data))
2674 		data = add_table(acpi_desc, &prev, data, end);
2675 
2676 	if (IS_ERR(data)) {
2677 		dev_dbg(dev, "%s: nfit table parsing error: %ld\n", __func__,
2678 				PTR_ERR(data));
2679 		rc = PTR_ERR(data);
2680 		goto out_unlock;
2681 	}
2682 
2683 	rc = acpi_nfit_check_deletions(acpi_desc, &prev);
2684 	if (rc)
2685 		goto out_unlock;
2686 
2687 	rc = nfit_mem_init(acpi_desc);
2688 	if (rc)
2689 		goto out_unlock;
2690 
2691 	rc = acpi_nfit_register_dimms(acpi_desc);
2692 	if (rc)
2693 		goto out_unlock;
2694 
2695 	rc = acpi_nfit_register_regions(acpi_desc);
2696 
2697  out_unlock:
2698 	mutex_unlock(&acpi_desc->init_mutex);
2699 	return rc;
2700 }
2701 EXPORT_SYMBOL_GPL(acpi_nfit_init);
2702 
2703 struct acpi_nfit_flush_work {
2704 	struct work_struct work;
2705 	struct completion cmp;
2706 };
2707 
2708 static void flush_probe(struct work_struct *work)
2709 {
2710 	struct acpi_nfit_flush_work *flush;
2711 
2712 	flush = container_of(work, typeof(*flush), work);
2713 	complete(&flush->cmp);
2714 }
2715 
2716 static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc)
2717 {
2718 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
2719 	struct device *dev = acpi_desc->dev;
2720 	struct acpi_nfit_flush_work flush;
2721 	int rc;
2722 
2723 	/* bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */
2724 	device_lock(dev);
2725 	device_unlock(dev);
2726 
2727 	/*
2728 	 * Scrub work could take 10s of seconds, userspace may give up so we
2729 	 * need to be interruptible while waiting.
2730 	 */
2731 	INIT_WORK_ONSTACK(&flush.work, flush_probe);
2732 	COMPLETION_INITIALIZER_ONSTACK(flush.cmp);
2733 	queue_work(nfit_wq, &flush.work);
2734 
2735 	rc = wait_for_completion_interruptible(&flush.cmp);
2736 	cancel_work_sync(&flush.work);
2737 	return rc;
2738 }
2739 
2740 static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
2741 		struct nvdimm *nvdimm, unsigned int cmd)
2742 {
2743 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
2744 
2745 	if (nvdimm)
2746 		return 0;
2747 	if (cmd != ND_CMD_ARS_START)
2748 		return 0;
2749 
2750 	/*
2751 	 * The kernel and userspace may race to initiate a scrub, but
2752 	 * the scrub thread is prepared to lose that initial race.  It
2753 	 * just needs guarantees that any ars it initiates are not
2754 	 * interrupted by any intervening start reqeusts from userspace.
2755 	 */
2756 	if (work_busy(&acpi_desc->work))
2757 		return -EBUSY;
2758 
2759 	return 0;
2760 }
2761 
2762 int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc)
2763 {
2764 	struct device *dev = acpi_desc->dev;
2765 	struct nfit_spa *nfit_spa;
2766 
2767 	if (work_busy(&acpi_desc->work))
2768 		return -EBUSY;
2769 
2770 	if (acpi_desc->cancel)
2771 		return 0;
2772 
2773 	mutex_lock(&acpi_desc->init_mutex);
2774 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
2775 		struct acpi_nfit_system_address *spa = nfit_spa->spa;
2776 
2777 		if (nfit_spa_type(spa) != NFIT_SPA_PM)
2778 			continue;
2779 
2780 		nfit_spa->ars_required = 1;
2781 	}
2782 	queue_work(nfit_wq, &acpi_desc->work);
2783 	dev_dbg(dev, "%s: ars_scan triggered\n", __func__);
2784 	mutex_unlock(&acpi_desc->init_mutex);
2785 
2786 	return 0;
2787 }
2788 
2789 void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
2790 {
2791 	struct nvdimm_bus_descriptor *nd_desc;
2792 
2793 	dev_set_drvdata(dev, acpi_desc);
2794 	acpi_desc->dev = dev;
2795 	acpi_desc->blk_do_io = acpi_nfit_blk_region_do_io;
2796 	nd_desc = &acpi_desc->nd_desc;
2797 	nd_desc->provider_name = "ACPI.NFIT";
2798 	nd_desc->module = THIS_MODULE;
2799 	nd_desc->ndctl = acpi_nfit_ctl;
2800 	nd_desc->flush_probe = acpi_nfit_flush_probe;
2801 	nd_desc->clear_to_send = acpi_nfit_clear_to_send;
2802 	nd_desc->attr_groups = acpi_nfit_attribute_groups;
2803 
2804 	INIT_LIST_HEAD(&acpi_desc->spas);
2805 	INIT_LIST_HEAD(&acpi_desc->dcrs);
2806 	INIT_LIST_HEAD(&acpi_desc->bdws);
2807 	INIT_LIST_HEAD(&acpi_desc->idts);
2808 	INIT_LIST_HEAD(&acpi_desc->flushes);
2809 	INIT_LIST_HEAD(&acpi_desc->memdevs);
2810 	INIT_LIST_HEAD(&acpi_desc->dimms);
2811 	INIT_LIST_HEAD(&acpi_desc->list);
2812 	mutex_init(&acpi_desc->init_mutex);
2813 	INIT_WORK(&acpi_desc->work, acpi_nfit_scrub);
2814 }
2815 EXPORT_SYMBOL_GPL(acpi_nfit_desc_init);
2816 
2817 static int acpi_nfit_add(struct acpi_device *adev)
2818 {
2819 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
2820 	struct acpi_nfit_desc *acpi_desc;
2821 	struct device *dev = &adev->dev;
2822 	struct acpi_table_header *tbl;
2823 	acpi_status status = AE_OK;
2824 	acpi_size sz;
2825 	int rc = 0;
2826 
2827 	status = acpi_get_table(ACPI_SIG_NFIT, 0, &tbl);
2828 	if (ACPI_FAILURE(status)) {
2829 		/* This is ok, we could have an nvdimm hotplugged later */
2830 		dev_dbg(dev, "failed to find NFIT at startup\n");
2831 		return 0;
2832 	}
2833 	sz = tbl->length;
2834 
2835 	acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
2836 	if (!acpi_desc)
2837 		return -ENOMEM;
2838 	acpi_nfit_desc_init(acpi_desc, &adev->dev);
2839 
2840 	/* Save the acpi header for exporting the revision via sysfs */
2841 	acpi_desc->acpi_header = *tbl;
2842 
2843 	/* Evaluate _FIT and override with that if present */
2844 	status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
2845 	if (ACPI_SUCCESS(status) && buf.length > 0) {
2846 		union acpi_object *obj = buf.pointer;
2847 
2848 		if (obj->type == ACPI_TYPE_BUFFER)
2849 			rc = acpi_nfit_init(acpi_desc, obj->buffer.pointer,
2850 					obj->buffer.length);
2851 		else
2852 			dev_dbg(dev, "%s invalid type %d, ignoring _FIT\n",
2853 				 __func__, (int) obj->type);
2854 		kfree(buf.pointer);
2855 	} else
2856 		/* skip over the lead-in header table */
2857 		rc = acpi_nfit_init(acpi_desc, (void *) tbl
2858 				+ sizeof(struct acpi_table_nfit),
2859 				sz - sizeof(struct acpi_table_nfit));
2860 	return rc;
2861 }
2862 
2863 static int acpi_nfit_remove(struct acpi_device *adev)
2864 {
2865 	/* see acpi_nfit_destruct */
2866 	return 0;
2867 }
2868 
2869 void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event)
2870 {
2871 	struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(dev);
2872 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
2873 	union acpi_object *obj;
2874 	acpi_status status;
2875 	int ret;
2876 
2877 	dev_dbg(dev, "%s: event: %d\n", __func__, event);
2878 
2879 	if (event != NFIT_NOTIFY_UPDATE)
2880 		return;
2881 
2882 	if (!dev->driver) {
2883 		/* dev->driver may be null if we're being removed */
2884 		dev_dbg(dev, "%s: no driver found for dev\n", __func__);
2885 		return;
2886 	}
2887 
2888 	if (!acpi_desc) {
2889 		acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
2890 		if (!acpi_desc)
2891 			return;
2892 		acpi_nfit_desc_init(acpi_desc, dev);
2893 	} else {
2894 		/*
2895 		 * Finish previous registration before considering new
2896 		 * regions.
2897 		 */
2898 		flush_workqueue(nfit_wq);
2899 	}
2900 
2901 	/* Evaluate _FIT */
2902 	status = acpi_evaluate_object(handle, "_FIT", NULL, &buf);
2903 	if (ACPI_FAILURE(status)) {
2904 		dev_err(dev, "failed to evaluate _FIT\n");
2905 		return;
2906 	}
2907 
2908 	obj = buf.pointer;
2909 	if (obj->type == ACPI_TYPE_BUFFER) {
2910 		ret = acpi_nfit_init(acpi_desc, obj->buffer.pointer,
2911 				obj->buffer.length);
2912 		if (ret)
2913 			dev_err(dev, "failed to merge updated NFIT\n");
2914 	} else
2915 		dev_err(dev, "Invalid _FIT\n");
2916 	kfree(buf.pointer);
2917 }
2918 EXPORT_SYMBOL_GPL(__acpi_nfit_notify);
2919 
2920 static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
2921 {
2922 	device_lock(&adev->dev);
2923 	__acpi_nfit_notify(&adev->dev, adev->handle, event);
2924 	device_unlock(&adev->dev);
2925 }
2926 
2927 static const struct acpi_device_id acpi_nfit_ids[] = {
2928 	{ "ACPI0012", 0 },
2929 	{ "", 0 },
2930 };
2931 MODULE_DEVICE_TABLE(acpi, acpi_nfit_ids);
2932 
2933 static struct acpi_driver acpi_nfit_driver = {
2934 	.name = KBUILD_MODNAME,
2935 	.ids = acpi_nfit_ids,
2936 	.ops = {
2937 		.add = acpi_nfit_add,
2938 		.remove = acpi_nfit_remove,
2939 		.notify = acpi_nfit_notify,
2940 	},
2941 };
2942 
2943 static __init int nfit_init(void)
2944 {
2945 	BUILD_BUG_ON(sizeof(struct acpi_table_nfit) != 40);
2946 	BUILD_BUG_ON(sizeof(struct acpi_nfit_system_address) != 56);
2947 	BUILD_BUG_ON(sizeof(struct acpi_nfit_memory_map) != 48);
2948 	BUILD_BUG_ON(sizeof(struct acpi_nfit_interleave) != 20);
2949 	BUILD_BUG_ON(sizeof(struct acpi_nfit_smbios) != 9);
2950 	BUILD_BUG_ON(sizeof(struct acpi_nfit_control_region) != 80);
2951 	BUILD_BUG_ON(sizeof(struct acpi_nfit_data_region) != 40);
2952 
2953 	acpi_str_to_uuid(UUID_VOLATILE_MEMORY, nfit_uuid[NFIT_SPA_VOLATILE]);
2954 	acpi_str_to_uuid(UUID_PERSISTENT_MEMORY, nfit_uuid[NFIT_SPA_PM]);
2955 	acpi_str_to_uuid(UUID_CONTROL_REGION, nfit_uuid[NFIT_SPA_DCR]);
2956 	acpi_str_to_uuid(UUID_DATA_REGION, nfit_uuid[NFIT_SPA_BDW]);
2957 	acpi_str_to_uuid(UUID_VOLATILE_VIRTUAL_DISK, nfit_uuid[NFIT_SPA_VDISK]);
2958 	acpi_str_to_uuid(UUID_VOLATILE_VIRTUAL_CD, nfit_uuid[NFIT_SPA_VCD]);
2959 	acpi_str_to_uuid(UUID_PERSISTENT_VIRTUAL_DISK, nfit_uuid[NFIT_SPA_PDISK]);
2960 	acpi_str_to_uuid(UUID_PERSISTENT_VIRTUAL_CD, nfit_uuid[NFIT_SPA_PCD]);
2961 	acpi_str_to_uuid(UUID_NFIT_BUS, nfit_uuid[NFIT_DEV_BUS]);
2962 	acpi_str_to_uuid(UUID_NFIT_DIMM, nfit_uuid[NFIT_DEV_DIMM]);
2963 	acpi_str_to_uuid(UUID_NFIT_DIMM_N_HPE1, nfit_uuid[NFIT_DEV_DIMM_N_HPE1]);
2964 	acpi_str_to_uuid(UUID_NFIT_DIMM_N_HPE2, nfit_uuid[NFIT_DEV_DIMM_N_HPE2]);
2965 	acpi_str_to_uuid(UUID_NFIT_DIMM_N_MSFT, nfit_uuid[NFIT_DEV_DIMM_N_MSFT]);
2966 
2967 	nfit_wq = create_singlethread_workqueue("nfit");
2968 	if (!nfit_wq)
2969 		return -ENOMEM;
2970 
2971 	nfit_mce_register();
2972 
2973 	return acpi_bus_register_driver(&acpi_nfit_driver);
2974 }
2975 
2976 static __exit void nfit_exit(void)
2977 {
2978 	nfit_mce_unregister();
2979 	acpi_bus_unregister_driver(&acpi_nfit_driver);
2980 	destroy_workqueue(nfit_wq);
2981 	WARN_ON(!list_empty(&acpi_descs));
2982 }
2983 
2984 module_init(nfit_init);
2985 module_exit(nfit_exit);
2986 MODULE_LICENSE("GPL v2");
2987 MODULE_AUTHOR("Intel Corporation");
2988