1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * GHES/EDAC Linux driver
4 *
5 * Copyright (c) 2013 by Mauro Carvalho Chehab
6 *
7 * Red Hat Inc. https://www.redhat.com
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <acpi/ghes.h>
13#include <linux/edac.h>
14#include <linux/dmi.h>
15#include "edac_module.h"
16#include <ras/ras_event.h>
17#include <linux/notifier.h>
18
19#define OTHER_DETAIL_LEN	400
20
21struct ghes_pvt {
22	struct mem_ctl_info *mci;
23
24	/* Buffers for the error handling routine */
25	char other_detail[OTHER_DETAIL_LEN];
26	char msg[80];
27};
28
29static refcount_t ghes_refcount = REFCOUNT_INIT(0);
30
31/*
32 * Access to ghes_pvt must be protected by ghes_lock. The spinlock
33 * also provides the necessary (implicit) memory barrier for the SMP
34 * case to make the pointer visible on another CPU.
35 */
36static struct ghes_pvt *ghes_pvt;
37
38/*
39 * This driver's representation of the system hardware, as collected
40 * from DMI.
41 */
42static struct ghes_hw_desc {
43	int num_dimms;
44	struct dimm_info *dimms;
45} ghes_hw;
46
47/* GHES registration mutex */
48static DEFINE_MUTEX(ghes_reg_mutex);
49
50/*
51 * Sync with other, potentially concurrent callers of
52 * ghes_edac_report_mem_error(). We don't know what the
53 * "inventive" firmware would do.
54 */
55static DEFINE_SPINLOCK(ghes_lock);
56
57static bool system_scanned;
58
59static struct list_head *ghes_devs;
60
61/* Memory Device - Type 17 of SMBIOS spec */
62struct memdev_dmi_entry {
63	u8 type;
64	u8 length;
65	u16 handle;
66	u16 phys_mem_array_handle;
67	u16 mem_err_info_handle;
68	u16 total_width;
69	u16 data_width;
70	u16 size;
71	u8 form_factor;
72	u8 device_set;
73	u8 device_locator;
74	u8 bank_locator;
75	u8 memory_type;
76	u16 type_detail;
77	u16 speed;
78	u8 manufacturer;
79	u8 serial_number;
80	u8 asset_tag;
81	u8 part_number;
82	u8 attributes;
83	u32 extended_size;
84	u16 conf_mem_clk_speed;
85} __attribute__((__packed__));
86
87static struct dimm_info *find_dimm_by_handle(struct mem_ctl_info *mci, u16 handle)
88{
89	struct dimm_info *dimm;
90
91	mci_for_each_dimm(mci, dimm) {
92		if (dimm->smbios_handle == handle)
93			return dimm;
94	}
95
96	return NULL;
97}
98
99static void dimm_setup_label(struct dimm_info *dimm, u16 handle)
100{
101	const char *bank = NULL, *device = NULL;
102
103	dmi_memdev_name(handle, &bank, &device);
104
105	/*
106	 * Set to a NULL string when both bank and device are zero. In this case,
107	 * the label assigned by default will be preserved.
108	 */
109	snprintf(dimm->label, sizeof(dimm->label), "%s%s%s",
110		 (bank && *bank) ? bank : "",
111		 (bank && *bank && device && *device) ? " " : "",
112		 (device && *device) ? device : "");
113}
114
115static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)
116{
117	u16 rdr_mask = BIT(7) | BIT(13);
118
119	if (entry->size == 0xffff) {
120		pr_info("Can't get DIMM%i size\n", dimm->idx);
121		dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
122	} else if (entry->size == 0x7fff) {
123		dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
124	} else {
125		if (entry->size & BIT(15))
126			dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
127		else
128			dimm->nr_pages = MiB_TO_PAGES(entry->size);
129	}
130
131	switch (entry->memory_type) {
132	case 0x12:
133		if (entry->type_detail & BIT(13))
134			dimm->mtype = MEM_RDDR;
135		else
136			dimm->mtype = MEM_DDR;
137		break;
138	case 0x13:
139		if (entry->type_detail & BIT(13))
140			dimm->mtype = MEM_RDDR2;
141		else
142			dimm->mtype = MEM_DDR2;
143		break;
144	case 0x14:
145		dimm->mtype = MEM_FB_DDR2;
146		break;
147	case 0x18:
148		if (entry->type_detail & BIT(12))
149			dimm->mtype = MEM_NVDIMM;
150		else if (entry->type_detail & BIT(13))
151			dimm->mtype = MEM_RDDR3;
152		else
153			dimm->mtype = MEM_DDR3;
154		break;
155	case 0x1a:
156		if (entry->type_detail & BIT(12))
157			dimm->mtype = MEM_NVDIMM;
158		else if (entry->type_detail & BIT(13))
159			dimm->mtype = MEM_RDDR4;
160		else
161			dimm->mtype = MEM_DDR4;
162		break;
163	default:
164		if (entry->type_detail & BIT(6))
165			dimm->mtype = MEM_RMBS;
166		else if ((entry->type_detail & rdr_mask) == rdr_mask)
167			dimm->mtype = MEM_RDR;
168		else if (entry->type_detail & BIT(7))
169			dimm->mtype = MEM_SDR;
170		else if (entry->type_detail & BIT(9))
171			dimm->mtype = MEM_EDO;
172		else
173			dimm->mtype = MEM_UNKNOWN;
174	}
175
176	/*
177	 * Actually, we can only detect if the memory has bits for
178	 * checksum or not
179	 */
180	if (entry->total_width == entry->data_width)
181		dimm->edac_mode = EDAC_NONE;
182	else
183		dimm->edac_mode = EDAC_SECDED;
184
185	dimm->dtype = DEV_UNKNOWN;
186	dimm->grain = 128;		/* Likely, worse case */
187
188	dimm_setup_label(dimm, entry->handle);
189
190	if (dimm->nr_pages) {
191		edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
192			dimm->idx, edac_mem_types[dimm->mtype],
193			PAGES_TO_MiB(dimm->nr_pages),
194			(dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
195		edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
196			entry->memory_type, entry->type_detail,
197			entry->total_width, entry->data_width);
198	}
199
200	dimm->smbios_handle = entry->handle;
201}
202
203static void enumerate_dimms(const struct dmi_header *dh, void *arg)
204{
205	struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
206	struct ghes_hw_desc *hw = (struct ghes_hw_desc *)arg;
207	struct dimm_info *d;
208
209	if (dh->type != DMI_ENTRY_MEM_DEVICE)
210		return;
211
212	/* Enlarge the array with additional 16 */
213	if (!hw->num_dimms || !(hw->num_dimms % 16)) {
214		struct dimm_info *new;
215
216		new = krealloc_array(hw->dimms, hw->num_dimms + 16,
217				     sizeof(struct dimm_info), GFP_KERNEL);
218		if (!new) {
219			WARN_ON_ONCE(1);
220			return;
221		}
222
223		hw->dimms = new;
224	}
225
226	d = &hw->dimms[hw->num_dimms];
227	d->idx = hw->num_dimms;
228
229	assign_dmi_dimm_info(d, entry);
230
231	hw->num_dimms++;
232}
233
234static void ghes_scan_system(void)
235{
236	if (system_scanned)
237		return;
238
239	dmi_walk(enumerate_dimms, &ghes_hw);
240
241	system_scanned = true;
242}
243
244static int print_mem_error_other_detail(const struct cper_sec_mem_err *mem, char *msg,
245					const char *location, unsigned int len)
246{
247	u32 n;
248
249	if (!msg)
250		return 0;
251
252	n = 0;
253	len -= 1;
254
255	n += scnprintf(msg + n, len - n, "APEI location: %s ", location);
256
257	if (!(mem->validation_bits & CPER_MEM_VALID_ERROR_STATUS))
258		goto out;
259
260	n += scnprintf(msg + n, len - n, "status(0x%016llx): ", mem->error_status);
261	n += scnprintf(msg + n, len - n, "%s ", cper_mem_err_status_str(mem->error_status));
262
263out:
264	msg[n] = '\0';
265
266	return n;
267}
268
269static int ghes_edac_report_mem_error(struct notifier_block *nb,
270				      unsigned long val, void *data)
271{
272	struct cper_sec_mem_err *mem_err = (struct cper_sec_mem_err *)data;
273	struct cper_mem_err_compact cmem;
274	struct edac_raw_error_desc *e;
275	struct mem_ctl_info *mci;
276	unsigned long sev = val;
277	struct ghes_pvt *pvt;
278	unsigned long flags;
279	char *p;
280
281	/*
282	 * We can do the locking below because GHES defers error processing
283	 * from NMI to IRQ context. Whenever that changes, we'd at least
284	 * know.
285	 */
286	if (WARN_ON_ONCE(in_nmi()))
287		return NOTIFY_OK;
288
289	spin_lock_irqsave(&ghes_lock, flags);
290
291	pvt = ghes_pvt;
292	if (!pvt)
293		goto unlock;
294
295	mci = pvt->mci;
296	e = &mci->error_desc;
297
298	/* Cleans the error report buffer */
299	memset(e, 0, sizeof (*e));
300	e->error_count = 1;
301	e->grain = 1;
302	e->msg = pvt->msg;
303	e->other_detail = pvt->other_detail;
304	e->top_layer = -1;
305	e->mid_layer = -1;
306	e->low_layer = -1;
307	*pvt->other_detail = '\0';
308	*pvt->msg = '\0';
309
310	switch (sev) {
311	case GHES_SEV_CORRECTED:
312		e->type = HW_EVENT_ERR_CORRECTED;
313		break;
314	case GHES_SEV_RECOVERABLE:
315		e->type = HW_EVENT_ERR_UNCORRECTED;
316		break;
317	case GHES_SEV_PANIC:
318		e->type = HW_EVENT_ERR_FATAL;
319		break;
320	default:
321	case GHES_SEV_NO:
322		e->type = HW_EVENT_ERR_INFO;
323	}
324
325	edac_dbg(1, "error validation_bits: 0x%08llx\n",
326		 (long long)mem_err->validation_bits);
327
328	/* Error type, mapped on e->msg */
329	if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
330		u8 etype = mem_err->error_type;
331
332		p = pvt->msg;
333		p += snprintf(p, sizeof(pvt->msg), "%s", cper_mem_err_type_str(etype));
334	} else {
335		strcpy(pvt->msg, "unknown error");
336	}
337
338	/* Error address */
339	if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
340		e->page_frame_number = PHYS_PFN(mem_err->physical_addr);
341		e->offset_in_page = offset_in_page(mem_err->physical_addr);
342	}
343
344	/* Error grain */
345	if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
346		e->grain = ~mem_err->physical_addr_mask + 1;
347
348	/* Memory error location, mapped on e->location */
349	p = e->location;
350	cper_mem_err_pack(mem_err, &cmem);
351	p += cper_mem_err_location(&cmem, p);
352
353	if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
354		struct dimm_info *dimm;
355
356		p += cper_dimm_err_location(&cmem, p);
357		dimm = find_dimm_by_handle(mci, mem_err->mem_dev_handle);
358		if (dimm) {
359			e->top_layer = dimm->idx;
360			strcpy(e->label, dimm->label);
361		}
362	}
363	if (p > e->location)
364		*(p - 1) = '\0';
365
366	if (!*e->label)
367		strcpy(e->label, "unknown memory");
368
369	/* All other fields are mapped on e->other_detail */
370	p = pvt->other_detail;
371	p += print_mem_error_other_detail(mem_err, p, e->location, OTHER_DETAIL_LEN);
372	if (p > pvt->other_detail)
373		*(p - 1) = '\0';
374
375	edac_raw_mc_handle_error(e);
376
377unlock:
378	spin_unlock_irqrestore(&ghes_lock, flags);
379
380	return NOTIFY_OK;
381}
382
383static struct notifier_block ghes_edac_mem_err_nb = {
384	.notifier_call	= ghes_edac_report_mem_error,
385	.priority	= 0,
386};
387
388static int ghes_edac_register(struct device *dev)
389{
390	bool fake = false;
391	struct mem_ctl_info *mci;
392	struct ghes_pvt *pvt;
393	struct edac_mc_layer layers[1];
394	unsigned long flags;
395	int rc = 0;
396
397	/* finish another registration/unregistration instance first */
398	mutex_lock(&ghes_reg_mutex);
399
400	/*
401	 * We have only one logical memory controller to which all DIMMs belong.
402	 */
403	if (refcount_inc_not_zero(&ghes_refcount))
404		goto unlock;
405
406	ghes_scan_system();
407
408	/* Check if we've got a bogus BIOS */
409	if (!ghes_hw.num_dimms) {
410		fake = true;
411		ghes_hw.num_dimms = 1;
412	}
413
414	layers[0].type = EDAC_MC_LAYER_ALL_MEM;
415	layers[0].size = ghes_hw.num_dimms;
416	layers[0].is_virt_csrow = true;
417
418	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_pvt));
419	if (!mci) {
420		pr_info("Can't allocate memory for EDAC data\n");
421		rc = -ENOMEM;
422		goto unlock;
423	}
424
425	pvt		= mci->pvt_info;
426	pvt->mci	= mci;
427
428	mci->pdev = dev;
429	mci->mtype_cap = MEM_FLAG_EMPTY;
430	mci->edac_ctl_cap = EDAC_FLAG_NONE;
431	mci->edac_cap = EDAC_FLAG_NONE;
432	mci->mod_name = "ghes_edac.c";
433	mci->ctl_name = "ghes_edac";
434	mci->dev_name = "ghes";
435
436	if (fake) {
437		pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
438		pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
439		pr_info("work on such system. Use this driver with caution\n");
440	}
441
442	pr_info("This system has %d DIMM sockets.\n", ghes_hw.num_dimms);
443
444	if (!fake) {
445		struct dimm_info *src, *dst;
446		int i = 0;
447
448		mci_for_each_dimm(mci, dst) {
449			src = &ghes_hw.dimms[i];
450
451			dst->idx	   = src->idx;
452			dst->smbios_handle = src->smbios_handle;
453			dst->nr_pages	   = src->nr_pages;
454			dst->mtype	   = src->mtype;
455			dst->edac_mode	   = src->edac_mode;
456			dst->dtype	   = src->dtype;
457			dst->grain	   = src->grain;
458
459			/*
460			 * If no src->label, preserve default label assigned
461			 * from EDAC core.
462			 */
463			if (strlen(src->label))
464				memcpy(dst->label, src->label, sizeof(src->label));
465
466			i++;
467		}
468
469	} else {
470		struct dimm_info *dimm = edac_get_dimm(mci, 0, 0, 0);
471
472		dimm->nr_pages = 1;
473		dimm->grain = 128;
474		dimm->mtype = MEM_UNKNOWN;
475		dimm->dtype = DEV_UNKNOWN;
476		dimm->edac_mode = EDAC_SECDED;
477	}
478
479	rc = edac_mc_add_mc(mci);
480	if (rc < 0) {
481		pr_info("Can't register with the EDAC core\n");
482		edac_mc_free(mci);
483		rc = -ENODEV;
484		goto unlock;
485	}
486
487	spin_lock_irqsave(&ghes_lock, flags);
488	ghes_pvt = pvt;
489	spin_unlock_irqrestore(&ghes_lock, flags);
490
491	ghes_register_report_chain(&ghes_edac_mem_err_nb);
492
493	/* only set on success */
494	refcount_set(&ghes_refcount, 1);
495
496unlock:
497
498	/* Not needed anymore */
499	kfree(ghes_hw.dimms);
500	ghes_hw.dimms = NULL;
501
502	mutex_unlock(&ghes_reg_mutex);
503
504	return rc;
505}
506
507static void ghes_edac_unregister(struct ghes *ghes)
508{
509	struct mem_ctl_info *mci;
510	unsigned long flags;
511
512	mutex_lock(&ghes_reg_mutex);
513
514	system_scanned = false;
515	memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc));
516
517	if (!refcount_dec_and_test(&ghes_refcount))
518		goto unlock;
519
520	/*
521	 * Wait for the irq handler being finished.
522	 */
523	spin_lock_irqsave(&ghes_lock, flags);
524	mci = ghes_pvt ? ghes_pvt->mci : NULL;
525	ghes_pvt = NULL;
526	spin_unlock_irqrestore(&ghes_lock, flags);
527
528	if (!mci)
529		goto unlock;
530
531	mci = edac_mc_del_mc(mci->pdev);
532	if (mci)
533		edac_mc_free(mci);
534
535	ghes_unregister_report_chain(&ghes_edac_mem_err_nb);
536
537unlock:
538	mutex_unlock(&ghes_reg_mutex);
539}
540
541static int __init ghes_edac_init(void)
542{
543	struct ghes *g, *g_tmp;
544
545	ghes_devs = ghes_get_devices();
546	if (!ghes_devs)
547		return -ENODEV;
548
549	if (list_empty(ghes_devs)) {
550		pr_info("GHES probing device list is empty");
551		return -ENODEV;
552	}
553
554	list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
555		ghes_edac_register(g->dev);
556	}
557
558	return 0;
559}
560module_init(ghes_edac_init);
561
562static void __exit ghes_edac_exit(void)
563{
564	struct ghes *g, *g_tmp;
565
566	list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
567		ghes_edac_unregister(g);
568	}
569}
570module_exit(ghes_edac_exit);
571
572MODULE_LICENSE("GPL");
573MODULE_DESCRIPTION("Output ACPI APEI/GHES BIOS detected errors via EDAC");
574