1 // SPDX-License-Identifier: GPL-2.0
2 
3 #define pr_fmt(fmt)	"papr-scm: " fmt
4 
5 #include <linux/of.h>
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/ioport.h>
9 #include <linux/slab.h>
10 #include <linux/ndctl.h>
11 #include <linux/sched.h>
12 #include <linux/libnvdimm.h>
13 #include <linux/platform_device.h>
14 #include <linux/delay.h>
15 #include <linux/seq_buf.h>
16 #include <linux/nd.h>
17 
18 #include <asm/plpar_wrappers.h>
19 #include <asm/papr_pdsm.h>
20 #include <asm/mce.h>
21 
22 #define BIND_ANY_ADDR (~0ul)
23 
24 #define PAPR_SCM_DIMM_CMD_MASK \
25 	((1ul << ND_CMD_GET_CONFIG_SIZE) | \
26 	 (1ul << ND_CMD_GET_CONFIG_DATA) | \
27 	 (1ul << ND_CMD_SET_CONFIG_DATA) | \
28 	 (1ul << ND_CMD_CALL))
29 
30 /* DIMM health bitmap bitmap indicators */
31 /* SCM device is unable to persist memory contents */
32 #define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
33 /* SCM device failed to persist memory contents */
34 #define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
35 /* SCM device contents are persisted from previous IPL */
36 #define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
37 /* SCM device contents are not persisted from previous IPL */
38 #define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
39 /* SCM device memory life remaining is critically low */
40 #define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
41 /* SCM device will be garded off next IPL due to failure */
42 #define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
43 /* SCM contents cannot persist due to current platform health status */
44 #define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
45 /* SCM device is unable to persist memory contents in certain conditions */
46 #define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
47 /* SCM device is encrypted */
48 #define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
49 /* SCM device has been scrubbed and locked */
50 #define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))
51 
52 /* Bits status indicators for health bitmap indicating unarmed dimm */
53 #define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |		\
54 				PAPR_PMEM_HEALTH_UNHEALTHY)
55 
56 /* Bits status indicators for health bitmap indicating unflushed dimm */
57 #define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
58 
59 /* Bits status indicators for health bitmap indicating unrestored dimm */
60 #define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)
61 
62 /* Bit status indicators for smart event notification */
63 #define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
64 				    PAPR_PMEM_HEALTH_FATAL |	\
65 				    PAPR_PMEM_HEALTH_UNHEALTHY)
66 
67 /* private struct associated with each region */
68 struct papr_scm_priv {
69 	struct platform_device *pdev;
70 	struct device_node *dn;
71 	uint32_t drc_index;
72 	uint64_t blocks;
73 	uint64_t block_size;
74 	int metadata_size;
75 	bool is_volatile;
76 
77 	uint64_t bound_addr;
78 
79 	struct nvdimm_bus_descriptor bus_desc;
80 	struct nvdimm_bus *bus;
81 	struct nvdimm *nvdimm;
82 	struct resource res;
83 	struct nd_region *region;
84 	struct nd_interleave_set nd_set;
85 	struct list_head region_list;
86 
87 	/* Protect dimm health data from concurrent read/writes */
88 	struct mutex health_mutex;
89 
90 	/* Last time the health information of the dimm was updated */
91 	unsigned long lasthealth_jiffies;
92 
93 	/* Health information for the dimm */
94 	u64 health_bitmap;
95 };
96 
97 LIST_HEAD(papr_nd_regions);
98 DEFINE_MUTEX(papr_ndr_lock);
99 
100 static int drc_pmem_bind(struct papr_scm_priv *p)
101 {
102 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
103 	uint64_t saved = 0;
104 	uint64_t token;
105 	int64_t rc;
106 
107 	/*
108 	 * When the hypervisor cannot map all the requested memory in a single
109 	 * hcall it returns H_BUSY and we call again with the token until
110 	 * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
111 	 * leave the system in an undefined state, so we wait.
112 	 */
113 	token = 0;
114 
115 	do {
116 		rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
117 				p->blocks, BIND_ANY_ADDR, token);
118 		token = ret[0];
119 		if (!saved)
120 			saved = ret[1];
121 		cond_resched();
122 	} while (rc == H_BUSY);
123 
124 	if (rc)
125 		return rc;
126 
127 	p->bound_addr = saved;
128 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
129 		p->drc_index, (unsigned long)saved);
130 	return rc;
131 }
132 
133 static void drc_pmem_unbind(struct papr_scm_priv *p)
134 {
135 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
136 	uint64_t token = 0;
137 	int64_t rc;
138 
139 	dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
140 
141 	/* NB: unbind has the same retry requirements as drc_pmem_bind() */
142 	do {
143 
144 		/* Unbind of all SCM resources associated with drcIndex */
145 		rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
146 				 p->drc_index, token);
147 		token = ret[0];
148 
149 		/* Check if we are stalled for some time */
150 		if (H_IS_LONG_BUSY(rc)) {
151 			msleep(get_longbusy_msecs(rc));
152 			rc = H_BUSY;
153 		} else if (rc == H_BUSY) {
154 			cond_resched();
155 		}
156 
157 	} while (rc == H_BUSY);
158 
159 	if (rc)
160 		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
161 	else
162 		dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
163 			p->drc_index);
164 
165 	return;
166 }
167 
168 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
169 {
170 	unsigned long start_addr;
171 	unsigned long end_addr;
172 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
173 	int64_t rc;
174 
175 
176 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
177 			 p->drc_index, 0);
178 	if (rc)
179 		goto err_out;
180 	start_addr = ret[0];
181 
182 	/* Make sure the full region is bound. */
183 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
184 			 p->drc_index, p->blocks - 1);
185 	if (rc)
186 		goto err_out;
187 	end_addr = ret[0];
188 
189 	if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
190 		goto err_out;
191 
192 	p->bound_addr = start_addr;
193 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
194 	return rc;
195 
196 err_out:
197 	dev_info(&p->pdev->dev,
198 		 "Failed to query, trying an unbind followed by bind");
199 	drc_pmem_unbind(p);
200 	return drc_pmem_bind(p);
201 }
202 
203 /*
204  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
205  * health information.
206  */
207 static int __drc_pmem_query_health(struct papr_scm_priv *p)
208 {
209 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
210 	long rc;
211 
212 	/* issue the hcall */
213 	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
214 	if (rc != H_SUCCESS) {
215 		dev_err(&p->pdev->dev,
216 			"Failed to query health information, Err:%ld\n", rc);
217 		return -ENXIO;
218 	}
219 
220 	p->lasthealth_jiffies = jiffies;
221 	p->health_bitmap = ret[0] & ret[1];
222 
223 	dev_dbg(&p->pdev->dev,
224 		"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
225 		ret[0], ret[1]);
226 
227 	return 0;
228 }
229 
230 /* Min interval in seconds for assuming stable dimm health */
231 #define MIN_HEALTH_QUERY_INTERVAL 60
232 
233 /* Query cached health info and if needed call drc_pmem_query_health */
234 static int drc_pmem_query_health(struct papr_scm_priv *p)
235 {
236 	unsigned long cache_timeout;
237 	int rc;
238 
239 	/* Protect concurrent modifications to papr_scm_priv */
240 	rc = mutex_lock_interruptible(&p->health_mutex);
241 	if (rc)
242 		return rc;
243 
244 	/* Jiffies offset for which the health data is assumed to be same */
245 	cache_timeout = p->lasthealth_jiffies +
246 		msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
247 
248 	/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
249 	if (time_after(jiffies, cache_timeout))
250 		rc = __drc_pmem_query_health(p);
251 	else
252 		/* Assume cached health data is valid */
253 		rc = 0;
254 
255 	mutex_unlock(&p->health_mutex);
256 	return rc;
257 }
258 
259 static int papr_scm_meta_get(struct papr_scm_priv *p,
260 			     struct nd_cmd_get_config_data_hdr *hdr)
261 {
262 	unsigned long data[PLPAR_HCALL_BUFSIZE];
263 	unsigned long offset, data_offset;
264 	int len, read;
265 	int64_t ret;
266 
267 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
268 		return -EINVAL;
269 
270 	for (len = hdr->in_length; len; len -= read) {
271 
272 		data_offset = hdr->in_length - len;
273 		offset = hdr->in_offset + data_offset;
274 
275 		if (len >= 8)
276 			read = 8;
277 		else if (len >= 4)
278 			read = 4;
279 		else if (len >= 2)
280 			read = 2;
281 		else
282 			read = 1;
283 
284 		ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
285 				  offset, read);
286 
287 		if (ret == H_PARAMETER) /* bad DRC index */
288 			return -ENODEV;
289 		if (ret)
290 			return -EINVAL; /* other invalid parameter */
291 
292 		switch (read) {
293 		case 8:
294 			*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
295 			break;
296 		case 4:
297 			*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
298 			break;
299 
300 		case 2:
301 			*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
302 			break;
303 
304 		case 1:
305 			*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
306 			break;
307 		}
308 	}
309 	return 0;
310 }
311 
312 static int papr_scm_meta_set(struct papr_scm_priv *p,
313 			     struct nd_cmd_set_config_hdr *hdr)
314 {
315 	unsigned long offset, data_offset;
316 	int len, wrote;
317 	unsigned long data;
318 	__be64 data_be;
319 	int64_t ret;
320 
321 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
322 		return -EINVAL;
323 
324 	for (len = hdr->in_length; len; len -= wrote) {
325 
326 		data_offset = hdr->in_length - len;
327 		offset = hdr->in_offset + data_offset;
328 
329 		if (len >= 8) {
330 			data = *(uint64_t *)(hdr->in_buf + data_offset);
331 			data_be = cpu_to_be64(data);
332 			wrote = 8;
333 		} else if (len >= 4) {
334 			data = *(uint32_t *)(hdr->in_buf + data_offset);
335 			data &= 0xffffffff;
336 			data_be = cpu_to_be32(data);
337 			wrote = 4;
338 		} else if (len >= 2) {
339 			data = *(uint16_t *)(hdr->in_buf + data_offset);
340 			data &= 0xffff;
341 			data_be = cpu_to_be16(data);
342 			wrote = 2;
343 		} else {
344 			data_be = *(uint8_t *)(hdr->in_buf + data_offset);
345 			data_be &= 0xff;
346 			wrote = 1;
347 		}
348 
349 		ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
350 					 offset, data_be, wrote);
351 		if (ret == H_PARAMETER) /* bad DRC index */
352 			return -ENODEV;
353 		if (ret)
354 			return -EINVAL; /* other invalid parameter */
355 	}
356 
357 	return 0;
358 }
359 
360 /*
361  * Do a sanity checks on the inputs args to dimm-control function and return
362  * '0' if valid. Validation of PDSM payloads happens later in
363  * papr_scm_service_pdsm.
364  */
365 static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
366 			unsigned int buf_len)
367 {
368 	unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
369 	struct nd_cmd_pkg *nd_cmd;
370 	struct papr_scm_priv *p;
371 	enum papr_pdsm pdsm;
372 
373 	/* Only dimm-specific calls are supported atm */
374 	if (!nvdimm)
375 		return -EINVAL;
376 
377 	/* get the provider data from struct nvdimm */
378 	p = nvdimm_provider_data(nvdimm);
379 
380 	if (!test_bit(cmd, &cmd_mask)) {
381 		dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
382 		return -EINVAL;
383 	}
384 
385 	/* For CMD_CALL verify pdsm request */
386 	if (cmd == ND_CMD_CALL) {
387 		/* Verify the envelope and envelop size */
388 		if (!buf ||
389 		    buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
390 			dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
391 				buf_len);
392 			return -EINVAL;
393 		}
394 
395 		/* Verify that the nd_cmd_pkg.nd_family is correct */
396 		nd_cmd = (struct nd_cmd_pkg *)buf;
397 
398 		if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
399 			dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
400 				nd_cmd->nd_family);
401 			return -EINVAL;
402 		}
403 
404 		pdsm = (enum papr_pdsm)nd_cmd->nd_command;
405 
406 		/* Verify if the pdsm command is valid */
407 		if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
408 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
409 				pdsm);
410 			return -EINVAL;
411 		}
412 
413 		/* Have enough space to hold returned 'nd_pkg_pdsm' header */
414 		if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
415 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
416 				pdsm);
417 			return -EINVAL;
418 		}
419 	}
420 
421 	/* Let the command be further processed */
422 	return 0;
423 }
424 
425 /* Fetch the DIMM health info and populate it in provided package. */
426 static int papr_pdsm_health(struct papr_scm_priv *p,
427 			    union nd_pdsm_payload *payload)
428 {
429 	int rc;
430 
431 	/* Ensure dimm health mutex is taken preventing concurrent access */
432 	rc = mutex_lock_interruptible(&p->health_mutex);
433 	if (rc)
434 		goto out;
435 
436 	/* Always fetch upto date dimm health data ignoring cached values */
437 	rc = __drc_pmem_query_health(p);
438 	if (rc) {
439 		mutex_unlock(&p->health_mutex);
440 		goto out;
441 	}
442 
443 	/* update health struct with various flags derived from health bitmap */
444 	payload->health = (struct nd_papr_pdsm_health) {
445 		.extension_flags = 0,
446 		.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
447 		.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
448 		.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
449 		.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
450 		.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
451 		.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
452 		.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
453 	};
454 
455 	/* Update field dimm_health based on health_bitmap flags */
456 	if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
457 		payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
458 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
459 		payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
460 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
461 		payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;
462 
463 	/* struct populated hence can release the mutex now */
464 	mutex_unlock(&p->health_mutex);
465 	rc = sizeof(struct nd_papr_pdsm_health);
466 
467 out:
468 	return rc;
469 }
470 
471 /*
472  * 'struct pdsm_cmd_desc'
473  * Identifies supported PDSMs' expected length of in/out payloads
474  * and pdsm service function.
475  *
476  * size_in	: Size of input payload if any in the PDSM request.
477  * size_out	: Size of output payload if any in the PDSM request.
478  * service	: Service function for the PDSM request. Return semantics:
479  *		  rc < 0 : Error servicing PDSM and rc indicates the error.
480  *		  rc >=0 : Serviced successfully and 'rc' indicate number of
481  *			bytes written to payload.
482  */
483 struct pdsm_cmd_desc {
484 	u32 size_in;
485 	u32 size_out;
486 	int (*service)(struct papr_scm_priv *dimm,
487 		       union nd_pdsm_payload *payload);
488 };
489 
490 /* Holds all supported PDSMs' command descriptors */
491 static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
492 	[PAPR_PDSM_MIN] = {
493 		.size_in = 0,
494 		.size_out = 0,
495 		.service = NULL,
496 	},
497 	/* New PDSM command descriptors to be added below */
498 
499 	[PAPR_PDSM_HEALTH] = {
500 		.size_in = 0,
501 		.size_out = sizeof(struct nd_papr_pdsm_health),
502 		.service = papr_pdsm_health,
503 	},
504 	/* Empty */
505 	[PAPR_PDSM_MAX] = {
506 		.size_in = 0,
507 		.size_out = 0,
508 		.service = NULL,
509 	},
510 };
511 
512 /* Given a valid pdsm cmd return its command descriptor else return NULL */
513 static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
514 {
515 	if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
516 		return &__pdsm_cmd_descriptors[cmd];
517 
518 	return NULL;
519 }
520 
521 /*
522  * For a given pdsm request call an appropriate service function.
523  * Returns errors if any while handling the pdsm command package.
524  */
525 static int papr_scm_service_pdsm(struct papr_scm_priv *p,
526 				 struct nd_cmd_pkg *pkg)
527 {
528 	/* Get the PDSM header and PDSM command */
529 	struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
530 	enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
531 	const struct pdsm_cmd_desc *pdsc;
532 	int rc;
533 
534 	/* Fetch corresponding pdsm descriptor for validation and servicing */
535 	pdsc = pdsm_cmd_desc(pdsm);
536 
537 	/* Validate pdsm descriptor */
538 	/* Ensure that reserved fields are 0 */
539 	if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
540 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
541 			pdsm);
542 		return -EINVAL;
543 	}
544 
545 	/* If pdsm expects some input, then ensure that the size_in matches */
546 	if (pdsc->size_in &&
547 	    pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
548 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
549 			pdsm, pkg->nd_size_in);
550 		return -EINVAL;
551 	}
552 
553 	/* If pdsm wants to return data, then ensure that  size_out matches */
554 	if (pdsc->size_out &&
555 	    pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
556 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
557 			pdsm, pkg->nd_size_out);
558 		return -EINVAL;
559 	}
560 
561 	/* Service the pdsm */
562 	if (pdsc->service) {
563 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
564 
565 		rc = pdsc->service(p, &pdsm_pkg->payload);
566 
567 		if (rc < 0) {
568 			/* error encountered while servicing pdsm */
569 			pdsm_pkg->cmd_status = rc;
570 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
571 		} else {
572 			/* pdsm serviced and 'rc' bytes written to payload */
573 			pdsm_pkg->cmd_status = 0;
574 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
575 		}
576 	} else {
577 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
578 			pdsm);
579 		pdsm_pkg->cmd_status = -ENOENT;
580 		pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
581 	}
582 
583 	return pdsm_pkg->cmd_status;
584 }
585 
586 static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
587 			  struct nvdimm *nvdimm, unsigned int cmd, void *buf,
588 			  unsigned int buf_len, int *cmd_rc)
589 {
590 	struct nd_cmd_get_config_size *get_size_hdr;
591 	struct nd_cmd_pkg *call_pkg = NULL;
592 	struct papr_scm_priv *p;
593 	int rc;
594 
595 	rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
596 	if (rc) {
597 		pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
598 		return rc;
599 	}
600 
601 	/* Use a local variable in case cmd_rc pointer is NULL */
602 	if (!cmd_rc)
603 		cmd_rc = &rc;
604 
605 	p = nvdimm_provider_data(nvdimm);
606 
607 	switch (cmd) {
608 	case ND_CMD_GET_CONFIG_SIZE:
609 		get_size_hdr = buf;
610 
611 		get_size_hdr->status = 0;
612 		get_size_hdr->max_xfer = 8;
613 		get_size_hdr->config_size = p->metadata_size;
614 		*cmd_rc = 0;
615 		break;
616 
617 	case ND_CMD_GET_CONFIG_DATA:
618 		*cmd_rc = papr_scm_meta_get(p, buf);
619 		break;
620 
621 	case ND_CMD_SET_CONFIG_DATA:
622 		*cmd_rc = papr_scm_meta_set(p, buf);
623 		break;
624 
625 	case ND_CMD_CALL:
626 		call_pkg = (struct nd_cmd_pkg *)buf;
627 		*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
628 		break;
629 
630 	default:
631 		dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
632 		return -EINVAL;
633 	}
634 
635 	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
636 
637 	return 0;
638 }
639 
640 static ssize_t flags_show(struct device *dev,
641 			  struct device_attribute *attr, char *buf)
642 {
643 	struct nvdimm *dimm = to_nvdimm(dev);
644 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
645 	struct seq_buf s;
646 	u64 health;
647 	int rc;
648 
649 	rc = drc_pmem_query_health(p);
650 	if (rc)
651 		return rc;
652 
653 	/* Copy health_bitmap locally, check masks & update out buffer */
654 	health = READ_ONCE(p->health_bitmap);
655 
656 	seq_buf_init(&s, buf, PAGE_SIZE);
657 	if (health & PAPR_PMEM_UNARMED_MASK)
658 		seq_buf_printf(&s, "not_armed ");
659 
660 	if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
661 		seq_buf_printf(&s, "flush_fail ");
662 
663 	if (health & PAPR_PMEM_BAD_RESTORE_MASK)
664 		seq_buf_printf(&s, "restore_fail ");
665 
666 	if (health & PAPR_PMEM_ENCRYPTED)
667 		seq_buf_printf(&s, "encrypted ");
668 
669 	if (health & PAPR_PMEM_SMART_EVENT_MASK)
670 		seq_buf_printf(&s, "smart_notify ");
671 
672 	if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
673 		seq_buf_printf(&s, "scrubbed locked ");
674 
675 	if (seq_buf_used(&s))
676 		seq_buf_printf(&s, "\n");
677 
678 	return seq_buf_used(&s);
679 }
680 DEVICE_ATTR_RO(flags);
681 
682 /* papr_scm specific dimm attributes */
683 static struct attribute *papr_nd_attributes[] = {
684 	&dev_attr_flags.attr,
685 	NULL,
686 };
687 
688 static struct attribute_group papr_nd_attribute_group = {
689 	.name = "papr",
690 	.attrs = papr_nd_attributes,
691 };
692 
693 static const struct attribute_group *papr_nd_attr_groups[] = {
694 	&papr_nd_attribute_group,
695 	NULL,
696 };
697 
698 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
699 {
700 	struct device *dev = &p->pdev->dev;
701 	struct nd_mapping_desc mapping;
702 	struct nd_region_desc ndr_desc;
703 	unsigned long dimm_flags;
704 	int target_nid, online_nid;
705 
706 	p->bus_desc.ndctl = papr_scm_ndctl;
707 	p->bus_desc.module = THIS_MODULE;
708 	p->bus_desc.of_node = p->pdev->dev.of_node;
709 	p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
710 
711 	if (!p->bus_desc.provider_name)
712 		return -ENOMEM;
713 
714 	p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
715 	if (!p->bus) {
716 		dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
717 		kfree(p->bus_desc.provider_name);
718 		return -ENXIO;
719 	}
720 
721 	dimm_flags = 0;
722 	set_bit(NDD_LABELING, &dimm_flags);
723 
724 	p->nvdimm = nvdimm_create(p->bus, p, papr_nd_attr_groups,
725 				  dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
726 	if (!p->nvdimm) {
727 		dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
728 		goto err;
729 	}
730 
731 	if (nvdimm_bus_check_dimm_count(p->bus, 1))
732 		goto err;
733 
734 	/* now add the region */
735 
736 	memset(&mapping, 0, sizeof(mapping));
737 	mapping.nvdimm = p->nvdimm;
738 	mapping.start = 0;
739 	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
740 
741 	memset(&ndr_desc, 0, sizeof(ndr_desc));
742 	target_nid = dev_to_node(&p->pdev->dev);
743 	online_nid = numa_map_to_online_node(target_nid);
744 	ndr_desc.numa_node = online_nid;
745 	ndr_desc.target_node = target_nid;
746 	ndr_desc.res = &p->res;
747 	ndr_desc.of_node = p->dn;
748 	ndr_desc.provider_data = p;
749 	ndr_desc.mapping = &mapping;
750 	ndr_desc.num_mappings = 1;
751 	ndr_desc.nd_set = &p->nd_set;
752 
753 	if (p->is_volatile)
754 		p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
755 	else {
756 		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
757 		p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
758 	}
759 	if (!p->region) {
760 		dev_err(dev, "Error registering region %pR from %pOF\n",
761 				ndr_desc.res, p->dn);
762 		goto err;
763 	}
764 	if (target_nid != online_nid)
765 		dev_info(dev, "Region registered with target node %d and online node %d",
766 			 target_nid, online_nid);
767 
768 	mutex_lock(&papr_ndr_lock);
769 	list_add_tail(&p->region_list, &papr_nd_regions);
770 	mutex_unlock(&papr_ndr_lock);
771 
772 	return 0;
773 
774 err:	nvdimm_bus_unregister(p->bus);
775 	kfree(p->bus_desc.provider_name);
776 	return -ENXIO;
777 }
778 
779 static void papr_scm_add_badblock(struct nd_region *region,
780 				  struct nvdimm_bus *bus, u64 phys_addr)
781 {
782 	u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
783 
784 	if (nvdimm_bus_add_badrange(bus, aligned_addr, L1_CACHE_BYTES)) {
785 		pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
786 		return;
787 	}
788 
789 	pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
790 		 aligned_addr, aligned_addr + L1_CACHE_BYTES);
791 
792 	nvdimm_region_notify(region, NVDIMM_REVALIDATE_POISON);
793 }
794 
795 static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
796 			 void *data)
797 {
798 	struct machine_check_event *evt = data;
799 	struct papr_scm_priv *p;
800 	u64 phys_addr;
801 	bool found = false;
802 
803 	if (evt->error_type != MCE_ERROR_TYPE_UE)
804 		return NOTIFY_DONE;
805 
806 	if (list_empty(&papr_nd_regions))
807 		return NOTIFY_DONE;
808 
809 	/*
810 	 * The physical address obtained here is PAGE_SIZE aligned, so get the
811 	 * exact address from the effective address
812 	 */
813 	phys_addr = evt->u.ue_error.physical_address +
814 			(evt->u.ue_error.effective_address & ~PAGE_MASK);
815 
816 	if (!evt->u.ue_error.physical_address_provided ||
817 	    !is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
818 		return NOTIFY_DONE;
819 
820 	/* mce notifier is called from a process context, so mutex is safe */
821 	mutex_lock(&papr_ndr_lock);
822 	list_for_each_entry(p, &papr_nd_regions, region_list) {
823 		if (phys_addr >= p->res.start && phys_addr <= p->res.end) {
824 			found = true;
825 			break;
826 		}
827 	}
828 
829 	if (found)
830 		papr_scm_add_badblock(p->region, p->bus, phys_addr);
831 
832 	mutex_unlock(&papr_ndr_lock);
833 
834 	return found ? NOTIFY_OK : NOTIFY_DONE;
835 }
836 
837 static struct notifier_block mce_ue_nb = {
838 	.notifier_call = handle_mce_ue
839 };
840 
841 static int papr_scm_probe(struct platform_device *pdev)
842 {
843 	struct device_node *dn = pdev->dev.of_node;
844 	u32 drc_index, metadata_size;
845 	u64 blocks, block_size;
846 	struct papr_scm_priv *p;
847 	const char *uuid_str;
848 	u64 uuid[2];
849 	int rc;
850 
851 	/* check we have all the required DT properties */
852 	if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
853 		dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
854 		return -ENODEV;
855 	}
856 
857 	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
858 		dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
859 		return -ENODEV;
860 	}
861 
862 	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
863 		dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
864 		return -ENODEV;
865 	}
866 
867 	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
868 		dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
869 		return -ENODEV;
870 	}
871 
872 
873 	p = kzalloc(sizeof(*p), GFP_KERNEL);
874 	if (!p)
875 		return -ENOMEM;
876 
877 	/* Initialize the dimm mutex */
878 	mutex_init(&p->health_mutex);
879 
880 	/* optional DT properties */
881 	of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
882 
883 	p->dn = dn;
884 	p->drc_index = drc_index;
885 	p->block_size = block_size;
886 	p->blocks = blocks;
887 	p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
888 
889 	/* We just need to ensure that set cookies are unique across */
890 	uuid_parse(uuid_str, (uuid_t *) uuid);
891 	/*
892 	 * cookie1 and cookie2 are not really little endian
893 	 * we store a little endian representation of the
894 	 * uuid str so that we can compare this with the label
895 	 * area cookie irrespective of the endian config with which
896 	 * the kernel is built.
897 	 */
898 	p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
899 	p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
900 
901 	/* might be zero */
902 	p->metadata_size = metadata_size;
903 	p->pdev = pdev;
904 
905 	/* request the hypervisor to bind this region to somewhere in memory */
906 	rc = drc_pmem_bind(p);
907 
908 	/* If phyp says drc memory still bound then force unbound and retry */
909 	if (rc == H_OVERLAP)
910 		rc = drc_pmem_query_n_bind(p);
911 
912 	if (rc != H_SUCCESS) {
913 		dev_err(&p->pdev->dev, "bind err: %d\n", rc);
914 		rc = -ENXIO;
915 		goto err;
916 	}
917 
918 	/* setup the resource for the newly bound range */
919 	p->res.start = p->bound_addr;
920 	p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
921 	p->res.name  = pdev->name;
922 	p->res.flags = IORESOURCE_MEM;
923 
924 	rc = papr_scm_nvdimm_init(p);
925 	if (rc)
926 		goto err2;
927 
928 	platform_set_drvdata(pdev, p);
929 
930 	return 0;
931 
932 err2:	drc_pmem_unbind(p);
933 err:	kfree(p);
934 	return rc;
935 }
936 
937 static int papr_scm_remove(struct platform_device *pdev)
938 {
939 	struct papr_scm_priv *p = platform_get_drvdata(pdev);
940 
941 	mutex_lock(&papr_ndr_lock);
942 	list_del(&p->region_list);
943 	mutex_unlock(&papr_ndr_lock);
944 
945 	nvdimm_bus_unregister(p->bus);
946 	drc_pmem_unbind(p);
947 	kfree(p->bus_desc.provider_name);
948 	kfree(p);
949 
950 	return 0;
951 }
952 
953 static const struct of_device_id papr_scm_match[] = {
954 	{ .compatible = "ibm,pmemory" },
955 	{ .compatible = "ibm,pmemory-v2" },
956 	{ },
957 };
958 
959 static struct platform_driver papr_scm_driver = {
960 	.probe = papr_scm_probe,
961 	.remove = papr_scm_remove,
962 	.driver = {
963 		.name = "papr_scm",
964 		.of_match_table = papr_scm_match,
965 	},
966 };
967 
968 static int __init papr_scm_init(void)
969 {
970 	int ret;
971 
972 	ret = platform_driver_register(&papr_scm_driver);
973 	if (!ret)
974 		mce_register_notifier(&mce_ue_nb);
975 
976 	return ret;
977 }
978 module_init(papr_scm_init);
979 
980 static void __exit papr_scm_exit(void)
981 {
982 	mce_unregister_notifier(&mce_ue_nb);
983 	platform_driver_unregister(&papr_scm_driver);
984 }
985 module_exit(papr_scm_exit);
986 
987 MODULE_DEVICE_TABLE(of, papr_scm_match);
988 MODULE_LICENSE("GPL");
989 MODULE_AUTHOR("IBM Corporation");
990