hwmon: (acpi_power_meter) Fix acpi_bus_get_device() return value check
[linux-drm-fsl-dcu.git] / drivers / edac / edac_mc.c
1 /*
2  * edac_mc kernel module
3  * (C) 2005, 2006 Linux Networx (http://lnxi.com)
4  * This file may be distributed under the terms of the
5  * GNU General Public License.
6  *
7  * Written by Thayne Harbaugh
8  * Based on work by Dan Hollis <goemon at anime dot net> and others.
9  *      http://www.anime.net/~goemon/linux-ecc/
10  *
11  * Modified by Dave Peterson and Doug Thompson
12  *
13  */
14
15 #include <linux/module.h>
16 #include <linux/proc_fs.h>
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/sysctl.h>
22 #include <linux/highmem.h>
23 #include <linux/timer.h>
24 #include <linux/slab.h>
25 #include <linux/jiffies.h>
26 #include <linux/spinlock.h>
27 #include <linux/list.h>
28 #include <linux/ctype.h>
29 #include <linux/edac.h>
30 #include <linux/bitops.h>
31 #include <asm/uaccess.h>
32 #include <asm/page.h>
33 #include <asm/edac.h>
34 #include "edac_core.h"
35 #include "edac_module.h"
36
37 #define CREATE_TRACE_POINTS
38 #define TRACE_INCLUDE_PATH ../../include/ras
39 #include <ras/ras_event.h>
40
41 /* lock to memory controller's control array */
42 static DEFINE_MUTEX(mem_ctls_mutex);
43 static LIST_HEAD(mc_devices);
44
45 /*
46  * Used to lock EDAC MC to just one module, avoiding two drivers e. g.
47  *      apei/ghes and i7core_edac to be used at the same time.
48  */
49 static void const *edac_mc_owner;
50
51 static struct bus_type mc_bus[EDAC_MAX_MCS];
52
53 unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf,
54                                  unsigned len)
55 {
56         struct mem_ctl_info *mci = dimm->mci;
57         int i, n, count = 0;
58         char *p = buf;
59
60         for (i = 0; i < mci->n_layers; i++) {
61                 n = snprintf(p, len, "%s %d ",
62                               edac_layer_name[mci->layers[i].type],
63                               dimm->location[i]);
64                 p += n;
65                 len -= n;
66                 count += n;
67                 if (!len)
68                         break;
69         }
70
71         return count;
72 }
73
74 #ifdef CONFIG_EDAC_DEBUG
75
76 static void edac_mc_dump_channel(struct rank_info *chan)
77 {
78         edac_dbg(4, "  channel->chan_idx = %d\n", chan->chan_idx);
79         edac_dbg(4, "    channel = %p\n", chan);
80         edac_dbg(4, "    channel->csrow = %p\n", chan->csrow);
81         edac_dbg(4, "    channel->dimm = %p\n", chan->dimm);
82 }
83
84 static void edac_mc_dump_dimm(struct dimm_info *dimm, int number)
85 {
86         char location[80];
87
88         edac_dimm_info_location(dimm, location, sizeof(location));
89
90         edac_dbg(4, "%s%i: %smapped as virtual row %d, chan %d\n",
91                  dimm->mci->csbased ? "rank" : "dimm",
92                  number, location, dimm->csrow, dimm->cschannel);
93         edac_dbg(4, "  dimm = %p\n", dimm);
94         edac_dbg(4, "  dimm->label = '%s'\n", dimm->label);
95         edac_dbg(4, "  dimm->nr_pages = 0x%x\n", dimm->nr_pages);
96         edac_dbg(4, "  dimm->grain = %d\n", dimm->grain);
97         edac_dbg(4, "  dimm->nr_pages = 0x%x\n", dimm->nr_pages);
98 }
99
100 static void edac_mc_dump_csrow(struct csrow_info *csrow)
101 {
102         edac_dbg(4, "csrow->csrow_idx = %d\n", csrow->csrow_idx);
103         edac_dbg(4, "  csrow = %p\n", csrow);
104         edac_dbg(4, "  csrow->first_page = 0x%lx\n", csrow->first_page);
105         edac_dbg(4, "  csrow->last_page = 0x%lx\n", csrow->last_page);
106         edac_dbg(4, "  csrow->page_mask = 0x%lx\n", csrow->page_mask);
107         edac_dbg(4, "  csrow->nr_channels = %d\n", csrow->nr_channels);
108         edac_dbg(4, "  csrow->channels = %p\n", csrow->channels);
109         edac_dbg(4, "  csrow->mci = %p\n", csrow->mci);
110 }
111
112 static void edac_mc_dump_mci(struct mem_ctl_info *mci)
113 {
114         edac_dbg(3, "\tmci = %p\n", mci);
115         edac_dbg(3, "\tmci->mtype_cap = %lx\n", mci->mtype_cap);
116         edac_dbg(3, "\tmci->edac_ctl_cap = %lx\n", mci->edac_ctl_cap);
117         edac_dbg(3, "\tmci->edac_cap = %lx\n", mci->edac_cap);
118         edac_dbg(4, "\tmci->edac_check = %p\n", mci->edac_check);
119         edac_dbg(3, "\tmci->nr_csrows = %d, csrows = %p\n",
120                  mci->nr_csrows, mci->csrows);
121         edac_dbg(3, "\tmci->nr_dimms = %d, dimms = %p\n",
122                  mci->tot_dimms, mci->dimms);
123         edac_dbg(3, "\tdev = %p\n", mci->pdev);
124         edac_dbg(3, "\tmod_name:ctl_name = %s:%s\n",
125                  mci->mod_name, mci->ctl_name);
126         edac_dbg(3, "\tpvt_info = %p\n\n", mci->pvt_info);
127 }
128
129 #endif                          /* CONFIG_EDAC_DEBUG */
130
131 /*
132  * keep those in sync with the enum mem_type
133  */
134 const char *edac_mem_types[] = {
135         "Empty csrow",
136         "Reserved csrow type",
137         "Unknown csrow type",
138         "Fast page mode RAM",
139         "Extended data out RAM",
140         "Burst Extended data out RAM",
141         "Single data rate SDRAM",
142         "Registered single data rate SDRAM",
143         "Double data rate SDRAM",
144         "Registered Double data rate SDRAM",
145         "Rambus DRAM",
146         "Unbuffered DDR2 RAM",
147         "Fully buffered DDR2",
148         "Registered DDR2 RAM",
149         "Rambus XDR",
150         "Unbuffered DDR3 RAM",
151         "Registered DDR3 RAM",
152 };
153 EXPORT_SYMBOL_GPL(edac_mem_types);
154
155 /**
156  * edac_align_ptr - Prepares the pointer offsets for a single-shot allocation
157  * @p:          pointer to a pointer with the memory offset to be used. At
158  *              return, this will be incremented to point to the next offset
159  * @size:       Size of the data structure to be reserved
160  * @n_elems:    Number of elements that should be reserved
161  *
162  * If 'size' is a constant, the compiler will optimize this whole function
163  * down to either a no-op or the addition of a constant to the value of '*p'.
164  *
165  * The 'p' pointer is absolutely needed to keep the proper advancing
166  * further in memory to the proper offsets when allocating the struct along
167  * with its embedded structs, as edac_device_alloc_ctl_info() does it
168  * above, for example.
169  *
170  * At return, the pointer 'p' will be incremented to be used on a next call
171  * to this function.
172  */
173 void *edac_align_ptr(void **p, unsigned size, int n_elems)
174 {
175         unsigned align, r;
176         void *ptr = *p;
177
178         *p += size * n_elems;
179
180         /*
181          * 'p' can possibly be an unaligned item X such that sizeof(X) is
182          * 'size'.  Adjust 'p' so that its alignment is at least as
183          * stringent as what the compiler would provide for X and return
184          * the aligned result.
185          * Here we assume that the alignment of a "long long" is the most
186          * stringent alignment that the compiler will ever provide by default.
187          * As far as I know, this is a reasonable assumption.
188          */
189         if (size > sizeof(long))
190                 align = sizeof(long long);
191         else if (size > sizeof(int))
192                 align = sizeof(long);
193         else if (size > sizeof(short))
194                 align = sizeof(int);
195         else if (size > sizeof(char))
196                 align = sizeof(short);
197         else
198                 return (char *)ptr;
199
200         r = (unsigned long)p % align;
201
202         if (r == 0)
203                 return (char *)ptr;
204
205         *p += align - r;
206
207         return (void *)(((unsigned long)ptr) + align - r);
208 }
209
210 static void _edac_mc_free(struct mem_ctl_info *mci)
211 {
212         int i, chn, row;
213         struct csrow_info *csr;
214         const unsigned int tot_dimms = mci->tot_dimms;
215         const unsigned int tot_channels = mci->num_cschannel;
216         const unsigned int tot_csrows = mci->nr_csrows;
217
218         if (mci->dimms) {
219                 for (i = 0; i < tot_dimms; i++)
220                         kfree(mci->dimms[i]);
221                 kfree(mci->dimms);
222         }
223         if (mci->csrows) {
224                 for (row = 0; row < tot_csrows; row++) {
225                         csr = mci->csrows[row];
226                         if (csr) {
227                                 if (csr->channels) {
228                                         for (chn = 0; chn < tot_channels; chn++)
229                                                 kfree(csr->channels[chn]);
230                                         kfree(csr->channels);
231                                 }
232                                 kfree(csr);
233                         }
234                 }
235                 kfree(mci->csrows);
236         }
237         kfree(mci);
238 }
239
240 /**
241  * edac_mc_alloc: Allocate and partially fill a struct mem_ctl_info structure
242  * @mc_num:             Memory controller number
243  * @n_layers:           Number of MC hierarchy layers
244  * layers:              Describes each layer as seen by the Memory Controller
245  * @size_pvt:           size of private storage needed
246  *
247  *
248  * Everything is kmalloc'ed as one big chunk - more efficient.
249  * Only can be used if all structures have the same lifetime - otherwise
250  * you have to allocate and initialize your own structures.
251  *
252  * Use edac_mc_free() to free mc structures allocated by this function.
253  *
254  * NOTE: drivers handle multi-rank memories in different ways: in some
255  * drivers, one multi-rank memory stick is mapped as one entry, while, in
256  * others, a single multi-rank memory stick would be mapped into several
257  * entries. Currently, this function will allocate multiple struct dimm_info
258  * on such scenarios, as grouping the multiple ranks require drivers change.
259  *
260  * Returns:
261  *      On failure: NULL
262  *      On success: struct mem_ctl_info pointer
263  */
264 struct mem_ctl_info *edac_mc_alloc(unsigned mc_num,
265                                    unsigned n_layers,
266                                    struct edac_mc_layer *layers,
267                                    unsigned sz_pvt)
268 {
269         struct mem_ctl_info *mci;
270         struct edac_mc_layer *layer;
271         struct csrow_info *csr;
272         struct rank_info *chan;
273         struct dimm_info *dimm;
274         u32 *ce_per_layer[EDAC_MAX_LAYERS], *ue_per_layer[EDAC_MAX_LAYERS];
275         unsigned pos[EDAC_MAX_LAYERS];
276         unsigned size, tot_dimms = 1, count = 1;
277         unsigned tot_csrows = 1, tot_channels = 1, tot_errcount = 0;
278         void *pvt, *p, *ptr = NULL;
279         int i, j, row, chn, n, len, off;
280         bool per_rank = false;
281
282         BUG_ON(n_layers > EDAC_MAX_LAYERS || n_layers == 0);
283         /*
284          * Calculate the total amount of dimms and csrows/cschannels while
285          * in the old API emulation mode
286          */
287         for (i = 0; i < n_layers; i++) {
288                 tot_dimms *= layers[i].size;
289                 if (layers[i].is_virt_csrow)
290                         tot_csrows *= layers[i].size;
291                 else
292                         tot_channels *= layers[i].size;
293
294                 if (layers[i].type == EDAC_MC_LAYER_CHIP_SELECT)
295                         per_rank = true;
296         }
297
298         /* Figure out the offsets of the various items from the start of an mc
299          * structure.  We want the alignment of each item to be at least as
300          * stringent as what the compiler would provide if we could simply
301          * hardcode everything into a single struct.
302          */
303         mci = edac_align_ptr(&ptr, sizeof(*mci), 1);
304         layer = edac_align_ptr(&ptr, sizeof(*layer), n_layers);
305         for (i = 0; i < n_layers; i++) {
306                 count *= layers[i].size;
307                 edac_dbg(4, "errcount layer %d size %d\n", i, count);
308                 ce_per_layer[i] = edac_align_ptr(&ptr, sizeof(u32), count);
309                 ue_per_layer[i] = edac_align_ptr(&ptr, sizeof(u32), count);
310                 tot_errcount += 2 * count;
311         }
312
313         edac_dbg(4, "allocating %d error counters\n", tot_errcount);
314         pvt = edac_align_ptr(&ptr, sz_pvt, 1);
315         size = ((unsigned long)pvt) + sz_pvt;
316
317         edac_dbg(1, "allocating %u bytes for mci data (%d %s, %d csrows/channels)\n",
318                  size,
319                  tot_dimms,
320                  per_rank ? "ranks" : "dimms",
321                  tot_csrows * tot_channels);
322
323         mci = kzalloc(size, GFP_KERNEL);
324         if (mci == NULL)
325                 return NULL;
326
327         /* Adjust pointers so they point within the memory we just allocated
328          * rather than an imaginary chunk of memory located at address 0.
329          */
330         layer = (struct edac_mc_layer *)(((char *)mci) + ((unsigned long)layer));
331         for (i = 0; i < n_layers; i++) {
332                 mci->ce_per_layer[i] = (u32 *)((char *)mci + ((unsigned long)ce_per_layer[i]));
333                 mci->ue_per_layer[i] = (u32 *)((char *)mci + ((unsigned long)ue_per_layer[i]));
334         }
335         pvt = sz_pvt ? (((char *)mci) + ((unsigned long)pvt)) : NULL;
336
337         /* setup index and various internal pointers */
338         mci->mc_idx = mc_num;
339         mci->tot_dimms = tot_dimms;
340         mci->pvt_info = pvt;
341         mci->n_layers = n_layers;
342         mci->layers = layer;
343         memcpy(mci->layers, layers, sizeof(*layer) * n_layers);
344         mci->nr_csrows = tot_csrows;
345         mci->num_cschannel = tot_channels;
346         mci->csbased = per_rank;
347
348         /*
349          * Alocate and fill the csrow/channels structs
350          */
351         mci->csrows = kcalloc(tot_csrows, sizeof(*mci->csrows), GFP_KERNEL);
352         if (!mci->csrows)
353                 goto error;
354         for (row = 0; row < tot_csrows; row++) {
355                 csr = kzalloc(sizeof(**mci->csrows), GFP_KERNEL);
356                 if (!csr)
357                         goto error;
358                 mci->csrows[row] = csr;
359                 csr->csrow_idx = row;
360                 csr->mci = mci;
361                 csr->nr_channels = tot_channels;
362                 csr->channels = kcalloc(tot_channels, sizeof(*csr->channels),
363                                         GFP_KERNEL);
364                 if (!csr->channels)
365                         goto error;
366
367                 for (chn = 0; chn < tot_channels; chn++) {
368                         chan = kzalloc(sizeof(**csr->channels), GFP_KERNEL);
369                         if (!chan)
370                                 goto error;
371                         csr->channels[chn] = chan;
372                         chan->chan_idx = chn;
373                         chan->csrow = csr;
374                 }
375         }
376
377         /*
378          * Allocate and fill the dimm structs
379          */
380         mci->dimms  = kcalloc(tot_dimms, sizeof(*mci->dimms), GFP_KERNEL);
381         if (!mci->dimms)
382                 goto error;
383
384         memset(&pos, 0, sizeof(pos));
385         row = 0;
386         chn = 0;
387         for (i = 0; i < tot_dimms; i++) {
388                 chan = mci->csrows[row]->channels[chn];
389                 off = EDAC_DIMM_OFF(layer, n_layers, pos[0], pos[1], pos[2]);
390                 if (off < 0 || off >= tot_dimms) {
391                         edac_mc_printk(mci, KERN_ERR, "EDAC core bug: EDAC_DIMM_OFF is trying to do an illegal data access\n");
392                         goto error;
393                 }
394
395                 dimm = kzalloc(sizeof(**mci->dimms), GFP_KERNEL);
396                 if (!dimm)
397                         goto error;
398                 mci->dimms[off] = dimm;
399                 dimm->mci = mci;
400
401                 /*
402                  * Copy DIMM location and initialize it.
403                  */
404                 len = sizeof(dimm->label);
405                 p = dimm->label;
406                 n = snprintf(p, len, "mc#%u", mc_num);
407                 p += n;
408                 len -= n;
409                 for (j = 0; j < n_layers; j++) {
410                         n = snprintf(p, len, "%s#%u",
411                                      edac_layer_name[layers[j].type],
412                                      pos[j]);
413                         p += n;
414                         len -= n;
415                         dimm->location[j] = pos[j];
416
417                         if (len <= 0)
418                                 break;
419                 }
420
421                 /* Link it to the csrows old API data */
422                 chan->dimm = dimm;
423                 dimm->csrow = row;
424                 dimm->cschannel = chn;
425
426                 /* Increment csrow location */
427                 if (layers[0].is_virt_csrow) {
428                         chn++;
429                         if (chn == tot_channels) {
430                                 chn = 0;
431                                 row++;
432                         }
433                 } else {
434                         row++;
435                         if (row == tot_csrows) {
436                                 row = 0;
437                                 chn++;
438                         }
439                 }
440
441                 /* Increment dimm location */
442                 for (j = n_layers - 1; j >= 0; j--) {
443                         pos[j]++;
444                         if (pos[j] < layers[j].size)
445                                 break;
446                         pos[j] = 0;
447                 }
448         }
449
450         mci->op_state = OP_ALLOC;
451
452         return mci;
453
454 error:
455         _edac_mc_free(mci);
456
457         return NULL;
458 }
459 EXPORT_SYMBOL_GPL(edac_mc_alloc);
460
461 /**
462  * edac_mc_free
463  *      'Free' a previously allocated 'mci' structure
464  * @mci: pointer to a struct mem_ctl_info structure
465  */
466 void edac_mc_free(struct mem_ctl_info *mci)
467 {
468         edac_dbg(1, "\n");
469
470         /* If we're not yet registered with sysfs free only what was allocated
471          * in edac_mc_alloc().
472          */
473         if (!device_is_registered(&mci->dev)) {
474                 _edac_mc_free(mci);
475                 return;
476         }
477
478         /* the mci instance is freed here, when the sysfs object is dropped */
479         edac_unregister_sysfs(mci);
480 }
481 EXPORT_SYMBOL_GPL(edac_mc_free);
482
483
484 /**
485  * find_mci_by_dev
486  *
487  *      scan list of controllers looking for the one that manages
488  *      the 'dev' device
489  * @dev: pointer to a struct device related with the MCI
490  */
491 struct mem_ctl_info *find_mci_by_dev(struct device *dev)
492 {
493         struct mem_ctl_info *mci;
494         struct list_head *item;
495
496         edac_dbg(3, "\n");
497
498         list_for_each(item, &mc_devices) {
499                 mci = list_entry(item, struct mem_ctl_info, link);
500
501                 if (mci->pdev == dev)
502                         return mci;
503         }
504
505         return NULL;
506 }
507 EXPORT_SYMBOL_GPL(find_mci_by_dev);
508
509 /*
510  * handler for EDAC to check if NMI type handler has asserted interrupt
511  */
512 static int edac_mc_assert_error_check_and_clear(void)
513 {
514         int old_state;
515
516         if (edac_op_state == EDAC_OPSTATE_POLL)
517                 return 1;
518
519         old_state = edac_err_assert;
520         edac_err_assert = 0;
521
522         return old_state;
523 }
524
525 /*
526  * edac_mc_workq_function
527  *      performs the operation scheduled by a workq request
528  */
529 static void edac_mc_workq_function(struct work_struct *work_req)
530 {
531         struct delayed_work *d_work = to_delayed_work(work_req);
532         struct mem_ctl_info *mci = to_edac_mem_ctl_work(d_work);
533
534         mutex_lock(&mem_ctls_mutex);
535
536         /* if this control struct has movd to offline state, we are done */
537         if (mci->op_state == OP_OFFLINE) {
538                 mutex_unlock(&mem_ctls_mutex);
539                 return;
540         }
541
542         /* Only poll controllers that are running polled and have a check */
543         if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL))
544                 mci->edac_check(mci);
545
546         mutex_unlock(&mem_ctls_mutex);
547
548         /* Reschedule */
549         queue_delayed_work(edac_workqueue, &mci->work,
550                         msecs_to_jiffies(edac_mc_get_poll_msec()));
551 }
552
553 /*
554  * edac_mc_workq_setup
555  *      initialize a workq item for this mci
556  *      passing in the new delay period in msec
557  *
558  *      locking model:
559  *
560  *              called with the mem_ctls_mutex held
561  */
562 static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
563 {
564         edac_dbg(0, "\n");
565
566         /* if this instance is not in the POLL state, then simply return */
567         if (mci->op_state != OP_RUNNING_POLL)
568                 return;
569
570         INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
571         mod_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
572 }
573
574 /*
575  * edac_mc_workq_teardown
576  *      stop the workq processing on this mci
577  *
578  *      locking model:
579  *
580  *              called WITHOUT lock held
581  */
582 static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
583 {
584         int status;
585
586         if (mci->op_state != OP_RUNNING_POLL)
587                 return;
588
589         status = cancel_delayed_work(&mci->work);
590         if (status == 0) {
591                 edac_dbg(0, "not canceled, flush the queue\n");
592
593                 /* workq instance might be running, wait for it */
594                 flush_workqueue(edac_workqueue);
595         }
596 }
597
598 /*
599  * edac_mc_reset_delay_period(unsigned long value)
600  *
601  *      user space has updated our poll period value, need to
602  *      reset our workq delays
603  */
604 void edac_mc_reset_delay_period(int value)
605 {
606         struct mem_ctl_info *mci;
607         struct list_head *item;
608
609         mutex_lock(&mem_ctls_mutex);
610
611         list_for_each(item, &mc_devices) {
612                 mci = list_entry(item, struct mem_ctl_info, link);
613
614                 edac_mc_workq_setup(mci, (unsigned long) value);
615         }
616
617         mutex_unlock(&mem_ctls_mutex);
618 }
619
620
621
622 /* Return 0 on success, 1 on failure.
623  * Before calling this function, caller must
624  * assign a unique value to mci->mc_idx.
625  *
626  *      locking model:
627  *
628  *              called with the mem_ctls_mutex lock held
629  */
630 static int add_mc_to_global_list(struct mem_ctl_info *mci)
631 {
632         struct list_head *item, *insert_before;
633         struct mem_ctl_info *p;
634
635         insert_before = &mc_devices;
636
637         p = find_mci_by_dev(mci->pdev);
638         if (unlikely(p != NULL))
639                 goto fail0;
640
641         list_for_each(item, &mc_devices) {
642                 p = list_entry(item, struct mem_ctl_info, link);
643
644                 if (p->mc_idx >= mci->mc_idx) {
645                         if (unlikely(p->mc_idx == mci->mc_idx))
646                                 goto fail1;
647
648                         insert_before = item;
649                         break;
650                 }
651         }
652
653         list_add_tail_rcu(&mci->link, insert_before);
654         atomic_inc(&edac_handlers);
655         return 0;
656
657 fail0:
658         edac_printk(KERN_WARNING, EDAC_MC,
659                 "%s (%s) %s %s already assigned %d\n", dev_name(p->pdev),
660                 edac_dev_name(mci), p->mod_name, p->ctl_name, p->mc_idx);
661         return 1;
662
663 fail1:
664         edac_printk(KERN_WARNING, EDAC_MC,
665                 "bug in low-level driver: attempt to assign\n"
666                 "    duplicate mc_idx %d in %s()\n", p->mc_idx, __func__);
667         return 1;
668 }
669
670 static int del_mc_from_global_list(struct mem_ctl_info *mci)
671 {
672         int handlers = atomic_dec_return(&edac_handlers);
673         list_del_rcu(&mci->link);
674
675         /* these are for safe removal of devices from global list while
676          * NMI handlers may be traversing list
677          */
678         synchronize_rcu();
679         INIT_LIST_HEAD(&mci->link);
680
681         return handlers;
682 }
683
684 /**
685  * edac_mc_find: Search for a mem_ctl_info structure whose index is 'idx'.
686  *
687  * If found, return a pointer to the structure.
688  * Else return NULL.
689  *
690  * Caller must hold mem_ctls_mutex.
691  */
692 struct mem_ctl_info *edac_mc_find(int idx)
693 {
694         struct list_head *item;
695         struct mem_ctl_info *mci;
696
697         list_for_each(item, &mc_devices) {
698                 mci = list_entry(item, struct mem_ctl_info, link);
699
700                 if (mci->mc_idx >= idx) {
701                         if (mci->mc_idx == idx)
702                                 return mci;
703
704                         break;
705                 }
706         }
707
708         return NULL;
709 }
710 EXPORT_SYMBOL(edac_mc_find);
711
712 /**
713  * edac_mc_add_mc: Insert the 'mci' structure into the mci global list and
714  *                 create sysfs entries associated with mci structure
715  * @mci: pointer to the mci structure to be added to the list
716  *
717  * Return:
718  *      0       Success
719  *      !0      Failure
720  */
721
722 /* FIXME - should a warning be printed if no error detection? correction? */
723 int edac_mc_add_mc(struct mem_ctl_info *mci)
724 {
725         int ret = -EINVAL;
726         edac_dbg(0, "\n");
727
728         if (mci->mc_idx >= EDAC_MAX_MCS) {
729                 pr_warn_once("Too many memory controllers: %d\n", mci->mc_idx);
730                 return -ENODEV;
731         }
732
733 #ifdef CONFIG_EDAC_DEBUG
734         if (edac_debug_level >= 3)
735                 edac_mc_dump_mci(mci);
736
737         if (edac_debug_level >= 4) {
738                 int i;
739
740                 for (i = 0; i < mci->nr_csrows; i++) {
741                         struct csrow_info *csrow = mci->csrows[i];
742                         u32 nr_pages = 0;
743                         int j;
744
745                         for (j = 0; j < csrow->nr_channels; j++)
746                                 nr_pages += csrow->channels[j]->dimm->nr_pages;
747                         if (!nr_pages)
748                                 continue;
749                         edac_mc_dump_csrow(csrow);
750                         for (j = 0; j < csrow->nr_channels; j++)
751                                 if (csrow->channels[j]->dimm->nr_pages)
752                                         edac_mc_dump_channel(csrow->channels[j]);
753                 }
754                 for (i = 0; i < mci->tot_dimms; i++)
755                         if (mci->dimms[i]->nr_pages)
756                                 edac_mc_dump_dimm(mci->dimms[i], i);
757         }
758 #endif
759         mutex_lock(&mem_ctls_mutex);
760
761         if (edac_mc_owner && edac_mc_owner != mci->mod_name) {
762                 ret = -EPERM;
763                 goto fail0;
764         }
765
766         if (add_mc_to_global_list(mci))
767                 goto fail0;
768
769         /* set load time so that error rate can be tracked */
770         mci->start_time = jiffies;
771
772         mci->bus = &mc_bus[mci->mc_idx];
773
774         if (edac_create_sysfs_mci_device(mci)) {
775                 edac_mc_printk(mci, KERN_WARNING,
776                         "failed to create sysfs device\n");
777                 goto fail1;
778         }
779
780         /* If there IS a check routine, then we are running POLLED */
781         if (mci->edac_check != NULL) {
782                 /* This instance is NOW RUNNING */
783                 mci->op_state = OP_RUNNING_POLL;
784
785                 edac_mc_workq_setup(mci, edac_mc_get_poll_msec());
786         } else {
787                 mci->op_state = OP_RUNNING_INTERRUPT;
788         }
789
790         /* Report action taken */
791         edac_mc_printk(mci, KERN_INFO, "Giving out device to '%s' '%s':"
792                 " DEV %s\n", mci->mod_name, mci->ctl_name, edac_dev_name(mci));
793
794         edac_mc_owner = mci->mod_name;
795
796         mutex_unlock(&mem_ctls_mutex);
797         return 0;
798
799 fail1:
800         del_mc_from_global_list(mci);
801
802 fail0:
803         mutex_unlock(&mem_ctls_mutex);
804         return ret;
805 }
806 EXPORT_SYMBOL_GPL(edac_mc_add_mc);
807
808 /**
809  * edac_mc_del_mc: Remove sysfs entries for specified mci structure and
810  *                 remove mci structure from global list
811  * @pdev: Pointer to 'struct device' representing mci structure to remove.
812  *
813  * Return pointer to removed mci structure, or NULL if device not found.
814  */
815 struct mem_ctl_info *edac_mc_del_mc(struct device *dev)
816 {
817         struct mem_ctl_info *mci;
818
819         edac_dbg(0, "\n");
820
821         mutex_lock(&mem_ctls_mutex);
822
823         /* find the requested mci struct in the global list */
824         mci = find_mci_by_dev(dev);
825         if (mci == NULL) {
826                 mutex_unlock(&mem_ctls_mutex);
827                 return NULL;
828         }
829
830         if (!del_mc_from_global_list(mci))
831                 edac_mc_owner = NULL;
832         mutex_unlock(&mem_ctls_mutex);
833
834         /* flush workq processes */
835         edac_mc_workq_teardown(mci);
836
837         /* marking MCI offline */
838         mci->op_state = OP_OFFLINE;
839
840         /* remove from sysfs */
841         edac_remove_sysfs_mci_device(mci);
842
843         edac_printk(KERN_INFO, EDAC_MC,
844                 "Removed device %d for %s %s: DEV %s\n", mci->mc_idx,
845                 mci->mod_name, mci->ctl_name, edac_dev_name(mci));
846
847         return mci;
848 }
849 EXPORT_SYMBOL_GPL(edac_mc_del_mc);
850
851 static void edac_mc_scrub_block(unsigned long page, unsigned long offset,
852                                 u32 size)
853 {
854         struct page *pg;
855         void *virt_addr;
856         unsigned long flags = 0;
857
858         edac_dbg(3, "\n");
859
860         /* ECC error page was not in our memory. Ignore it. */
861         if (!pfn_valid(page))
862                 return;
863
864         /* Find the actual page structure then map it and fix */
865         pg = pfn_to_page(page);
866
867         if (PageHighMem(pg))
868                 local_irq_save(flags);
869
870         virt_addr = kmap_atomic(pg);
871
872         /* Perform architecture specific atomic scrub operation */
873         atomic_scrub(virt_addr + offset, size);
874
875         /* Unmap and complete */
876         kunmap_atomic(virt_addr);
877
878         if (PageHighMem(pg))
879                 local_irq_restore(flags);
880 }
881
882 /* FIXME - should return -1 */
883 int edac_mc_find_csrow_by_page(struct mem_ctl_info *mci, unsigned long page)
884 {
885         struct csrow_info **csrows = mci->csrows;
886         int row, i, j, n;
887
888         edac_dbg(1, "MC%d: 0x%lx\n", mci->mc_idx, page);
889         row = -1;
890
891         for (i = 0; i < mci->nr_csrows; i++) {
892                 struct csrow_info *csrow = csrows[i];
893                 n = 0;
894                 for (j = 0; j < csrow->nr_channels; j++) {
895                         struct dimm_info *dimm = csrow->channels[j]->dimm;
896                         n += dimm->nr_pages;
897                 }
898                 if (n == 0)
899                         continue;
900
901                 edac_dbg(3, "MC%d: first(0x%lx) page(0x%lx) last(0x%lx) mask(0x%lx)\n",
902                          mci->mc_idx,
903                          csrow->first_page, page, csrow->last_page,
904                          csrow->page_mask);
905
906                 if ((page >= csrow->first_page) &&
907                     (page <= csrow->last_page) &&
908                     ((page & csrow->page_mask) ==
909                      (csrow->first_page & csrow->page_mask))) {
910                         row = i;
911                         break;
912                 }
913         }
914
915         if (row == -1)
916                 edac_mc_printk(mci, KERN_ERR,
917                         "could not look up page error address %lx\n",
918                         (unsigned long)page);
919
920         return row;
921 }
922 EXPORT_SYMBOL_GPL(edac_mc_find_csrow_by_page);
923
924 const char *edac_layer_name[] = {
925         [EDAC_MC_LAYER_BRANCH] = "branch",
926         [EDAC_MC_LAYER_CHANNEL] = "channel",
927         [EDAC_MC_LAYER_SLOT] = "slot",
928         [EDAC_MC_LAYER_CHIP_SELECT] = "csrow",
929         [EDAC_MC_LAYER_ALL_MEM] = "memory",
930 };
931 EXPORT_SYMBOL_GPL(edac_layer_name);
932
933 static void edac_inc_ce_error(struct mem_ctl_info *mci,
934                               bool enable_per_layer_report,
935                               const int pos[EDAC_MAX_LAYERS],
936                               const u16 count)
937 {
938         int i, index = 0;
939
940         mci->ce_mc += count;
941
942         if (!enable_per_layer_report) {
943                 mci->ce_noinfo_count += count;
944                 return;
945         }
946
947         for (i = 0; i < mci->n_layers; i++) {
948                 if (pos[i] < 0)
949                         break;
950                 index += pos[i];
951                 mci->ce_per_layer[i][index] += count;
952
953                 if (i < mci->n_layers - 1)
954                         index *= mci->layers[i + 1].size;
955         }
956 }
957
958 static void edac_inc_ue_error(struct mem_ctl_info *mci,
959                                     bool enable_per_layer_report,
960                                     const int pos[EDAC_MAX_LAYERS],
961                                     const u16 count)
962 {
963         int i, index = 0;
964
965         mci->ue_mc += count;
966
967         if (!enable_per_layer_report) {
968                 mci->ce_noinfo_count += count;
969                 return;
970         }
971
972         for (i = 0; i < mci->n_layers; i++) {
973                 if (pos[i] < 0)
974                         break;
975                 index += pos[i];
976                 mci->ue_per_layer[i][index] += count;
977
978                 if (i < mci->n_layers - 1)
979                         index *= mci->layers[i + 1].size;
980         }
981 }
982
983 static void edac_ce_error(struct mem_ctl_info *mci,
984                           const u16 error_count,
985                           const int pos[EDAC_MAX_LAYERS],
986                           const char *msg,
987                           const char *location,
988                           const char *label,
989                           const char *detail,
990                           const char *other_detail,
991                           const bool enable_per_layer_report,
992                           const unsigned long page_frame_number,
993                           const unsigned long offset_in_page,
994                           long grain)
995 {
996         unsigned long remapped_page;
997         char *msg_aux = "";
998
999         if (*msg)
1000                 msg_aux = " ";
1001
1002         if (edac_mc_get_log_ce()) {
1003                 if (other_detail && *other_detail)
1004                         edac_mc_printk(mci, KERN_WARNING,
1005                                        "%d CE %s%son %s (%s %s - %s)\n",
1006                                        error_count, msg, msg_aux, label,
1007                                        location, detail, other_detail);
1008                 else
1009                         edac_mc_printk(mci, KERN_WARNING,
1010                                        "%d CE %s%son %s (%s %s)\n",
1011                                        error_count, msg, msg_aux, label,
1012                                        location, detail);
1013         }
1014         edac_inc_ce_error(mci, enable_per_layer_report, pos, error_count);
1015
1016         if (mci->scrub_mode & SCRUB_SW_SRC) {
1017                 /*
1018                         * Some memory controllers (called MCs below) can remap
1019                         * memory so that it is still available at a different
1020                         * address when PCI devices map into memory.
1021                         * MC's that can't do this, lose the memory where PCI
1022                         * devices are mapped. This mapping is MC-dependent
1023                         * and so we call back into the MC driver for it to
1024                         * map the MC page to a physical (CPU) page which can
1025                         * then be mapped to a virtual page - which can then
1026                         * be scrubbed.
1027                         */
1028                 remapped_page = mci->ctl_page_to_phys ?
1029                         mci->ctl_page_to_phys(mci, page_frame_number) :
1030                         page_frame_number;
1031
1032                 edac_mc_scrub_block(remapped_page,
1033                                         offset_in_page, grain);
1034         }
1035 }
1036
1037 static void edac_ue_error(struct mem_ctl_info *mci,
1038                           const u16 error_count,
1039                           const int pos[EDAC_MAX_LAYERS],
1040                           const char *msg,
1041                           const char *location,
1042                           const char *label,
1043                           const char *detail,
1044                           const char *other_detail,
1045                           const bool enable_per_layer_report)
1046 {
1047         char *msg_aux = "";
1048
1049         if (*msg)
1050                 msg_aux = " ";
1051
1052         if (edac_mc_get_log_ue()) {
1053                 if (other_detail && *other_detail)
1054                         edac_mc_printk(mci, KERN_WARNING,
1055                                        "%d UE %s%son %s (%s %s - %s)\n",
1056                                        error_count, msg, msg_aux, label,
1057                                        location, detail, other_detail);
1058                 else
1059                         edac_mc_printk(mci, KERN_WARNING,
1060                                        "%d UE %s%son %s (%s %s)\n",
1061                                        error_count, msg, msg_aux, label,
1062                                        location, detail);
1063         }
1064
1065         if (edac_mc_get_panic_on_ue()) {
1066                 if (other_detail && *other_detail)
1067                         panic("UE %s%son %s (%s%s - %s)\n",
1068                               msg, msg_aux, label, location, detail, other_detail);
1069                 else
1070                         panic("UE %s%son %s (%s%s)\n",
1071                               msg, msg_aux, label, location, detail);
1072         }
1073
1074         edac_inc_ue_error(mci, enable_per_layer_report, pos, error_count);
1075 }
1076
1077 /**
1078  * edac_raw_mc_handle_error - reports a memory event to userspace without doing
1079  *                            anything to discover the error location
1080  *
1081  * @type:               severity of the error (CE/UE/Fatal)
1082  * @mci:                a struct mem_ctl_info pointer
1083  * @e:                  error description
1084  *
1085  * This raw function is used internally by edac_mc_handle_error(). It should
1086  * only be called directly when the hardware error come directly from BIOS,
1087  * like in the case of APEI GHES driver.
1088  */
1089 void edac_raw_mc_handle_error(const enum hw_event_mc_err_type type,
1090                               struct mem_ctl_info *mci,
1091                               struct edac_raw_error_desc *e)
1092 {
1093         char detail[80];
1094         int pos[EDAC_MAX_LAYERS] = { e->top_layer, e->mid_layer, e->low_layer };
1095
1096         /* Memory type dependent details about the error */
1097         if (type == HW_EVENT_ERR_CORRECTED) {
1098                 snprintf(detail, sizeof(detail),
1099                         "page:0x%lx offset:0x%lx grain:%ld syndrome:0x%lx",
1100                         e->page_frame_number, e->offset_in_page,
1101                         e->grain, e->syndrome);
1102                 edac_ce_error(mci, e->error_count, pos, e->msg, e->location, e->label,
1103                               detail, e->other_detail, e->enable_per_layer_report,
1104                               e->page_frame_number, e->offset_in_page, e->grain);
1105         } else {
1106                 snprintf(detail, sizeof(detail),
1107                         "page:0x%lx offset:0x%lx grain:%ld",
1108                         e->page_frame_number, e->offset_in_page, e->grain);
1109
1110                 edac_ue_error(mci, e->error_count, pos, e->msg, e->location, e->label,
1111                               detail, e->other_detail, e->enable_per_layer_report);
1112         }
1113
1114
1115 }
1116 EXPORT_SYMBOL_GPL(edac_raw_mc_handle_error);
1117
1118 /**
1119  * edac_mc_handle_error - reports a memory event to userspace
1120  *
1121  * @type:               severity of the error (CE/UE/Fatal)
1122  * @mci:                a struct mem_ctl_info pointer
1123  * @error_count:        Number of errors of the same type
1124  * @page_frame_number:  mem page where the error occurred
1125  * @offset_in_page:     offset of the error inside the page
1126  * @syndrome:           ECC syndrome
1127  * @top_layer:          Memory layer[0] position
1128  * @mid_layer:          Memory layer[1] position
1129  * @low_layer:          Memory layer[2] position
1130  * @msg:                Message meaningful to the end users that
1131  *                      explains the event
1132  * @other_detail:       Technical details about the event that
1133  *                      may help hardware manufacturers and
1134  *                      EDAC developers to analyse the event
1135  */
1136 void edac_mc_handle_error(const enum hw_event_mc_err_type type,
1137                           struct mem_ctl_info *mci,
1138                           const u16 error_count,
1139                           const unsigned long page_frame_number,
1140                           const unsigned long offset_in_page,
1141                           const unsigned long syndrome,
1142                           const int top_layer,
1143                           const int mid_layer,
1144                           const int low_layer,
1145                           const char *msg,
1146                           const char *other_detail)
1147 {
1148         char *p;
1149         int row = -1, chan = -1;
1150         int pos[EDAC_MAX_LAYERS] = { top_layer, mid_layer, low_layer };
1151         int i, n_labels = 0;
1152         u8 grain_bits;
1153         struct edac_raw_error_desc *e = &mci->error_desc;
1154
1155         edac_dbg(3, "MC%d\n", mci->mc_idx);
1156
1157         /* Fills the error report buffer */
1158         memset(e, 0, sizeof (*e));
1159         e->error_count = error_count;
1160         e->top_layer = top_layer;
1161         e->mid_layer = mid_layer;
1162         e->low_layer = low_layer;
1163         e->page_frame_number = page_frame_number;
1164         e->offset_in_page = offset_in_page;
1165         e->syndrome = syndrome;
1166         e->msg = msg;
1167         e->other_detail = other_detail;
1168
1169         /*
1170          * Check if the event report is consistent and if the memory
1171          * location is known. If it is known, enable_per_layer_report will be
1172          * true, the DIMM(s) label info will be filled and the per-layer
1173          * error counters will be incremented.
1174          */
1175         for (i = 0; i < mci->n_layers; i++) {
1176                 if (pos[i] >= (int)mci->layers[i].size) {
1177
1178                         edac_mc_printk(mci, KERN_ERR,
1179                                        "INTERNAL ERROR: %s value is out of range (%d >= %d)\n",
1180                                        edac_layer_name[mci->layers[i].type],
1181                                        pos[i], mci->layers[i].size);
1182                         /*
1183                          * Instead of just returning it, let's use what's
1184                          * known about the error. The increment routines and
1185                          * the DIMM filter logic will do the right thing by
1186                          * pointing the likely damaged DIMMs.
1187                          */
1188                         pos[i] = -1;
1189                 }
1190                 if (pos[i] >= 0)
1191                         e->enable_per_layer_report = true;
1192         }
1193
1194         /*
1195          * Get the dimm label/grain that applies to the match criteria.
1196          * As the error algorithm may not be able to point to just one memory
1197          * stick, the logic here will get all possible labels that could
1198          * pottentially be affected by the error.
1199          * On FB-DIMM memory controllers, for uncorrected errors, it is common
1200          * to have only the MC channel and the MC dimm (also called "branch")
1201          * but the channel is not known, as the memory is arranged in pairs,
1202          * where each memory belongs to a separate channel within the same
1203          * branch.
1204          */
1205         p = e->label;
1206         *p = '\0';
1207
1208         for (i = 0; i < mci->tot_dimms; i++) {
1209                 struct dimm_info *dimm = mci->dimms[i];
1210
1211                 if (top_layer >= 0 && top_layer != dimm->location[0])
1212                         continue;
1213                 if (mid_layer >= 0 && mid_layer != dimm->location[1])
1214                         continue;
1215                 if (low_layer >= 0 && low_layer != dimm->location[2])
1216                         continue;
1217
1218                 /* get the max grain, over the error match range */
1219                 if (dimm->grain > e->grain)
1220                         e->grain = dimm->grain;
1221
1222                 /*
1223                  * If the error is memory-controller wide, there's no need to
1224                  * seek for the affected DIMMs because the whole
1225                  * channel/memory controller/...  may be affected.
1226                  * Also, don't show errors for empty DIMM slots.
1227                  */
1228                 if (e->enable_per_layer_report && dimm->nr_pages) {
1229                         if (n_labels >= EDAC_MAX_LABELS) {
1230                                 e->enable_per_layer_report = false;
1231                                 break;
1232                         }
1233                         n_labels++;
1234                         if (p != e->label) {
1235                                 strcpy(p, OTHER_LABEL);
1236                                 p += strlen(OTHER_LABEL);
1237                         }
1238                         strcpy(p, dimm->label);
1239                         p += strlen(p);
1240                         *p = '\0';
1241
1242                         /*
1243                          * get csrow/channel of the DIMM, in order to allow
1244                          * incrementing the compat API counters
1245                          */
1246                         edac_dbg(4, "%s csrows map: (%d,%d)\n",
1247                                  mci->csbased ? "rank" : "dimm",
1248                                  dimm->csrow, dimm->cschannel);
1249                         if (row == -1)
1250                                 row = dimm->csrow;
1251                         else if (row >= 0 && row != dimm->csrow)
1252                                 row = -2;
1253
1254                         if (chan == -1)
1255                                 chan = dimm->cschannel;
1256                         else if (chan >= 0 && chan != dimm->cschannel)
1257                                 chan = -2;
1258                 }
1259         }
1260
1261         if (!e->enable_per_layer_report) {
1262                 strcpy(e->label, "any memory");
1263         } else {
1264                 edac_dbg(4, "csrow/channel to increment: (%d,%d)\n", row, chan);
1265                 if (p == e->label)
1266                         strcpy(e->label, "unknown memory");
1267                 if (type == HW_EVENT_ERR_CORRECTED) {
1268                         if (row >= 0) {
1269                                 mci->csrows[row]->ce_count += error_count;
1270                                 if (chan >= 0)
1271                                         mci->csrows[row]->channels[chan]->ce_count += error_count;
1272                         }
1273                 } else
1274                         if (row >= 0)
1275                                 mci->csrows[row]->ue_count += error_count;
1276         }
1277
1278         /* Fill the RAM location data */
1279         p = e->location;
1280
1281         for (i = 0; i < mci->n_layers; i++) {
1282                 if (pos[i] < 0)
1283                         continue;
1284
1285                 p += sprintf(p, "%s:%d ",
1286                              edac_layer_name[mci->layers[i].type],
1287                              pos[i]);
1288         }
1289         if (p > e->location)
1290                 *(p - 1) = '\0';
1291
1292         /* Report the error via the trace interface */
1293         grain_bits = fls_long(e->grain) + 1;
1294         trace_mc_event(type, e->msg, e->label, e->error_count,
1295                        mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer,
1296                        PAGES_TO_MiB(e->page_frame_number) | e->offset_in_page,
1297                        grain_bits, e->syndrome, e->other_detail);
1298
1299         edac_raw_mc_handle_error(type, mci, e);
1300 }
1301 EXPORT_SYMBOL_GPL(edac_mc_handle_error);