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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 "edac_core.h"
34 #include "edac_module.h"
35 #include <ras/ras_event.h>
36
37 #ifdef CONFIG_EDAC_ATOMIC_SCRUB
38 #include <asm/edac.h>
39 #else
40 #define edac_atomic_scrub(va, size) do { } while (0)
41 #endif
42
43 /* lock to memory controller's control array */
44 static DEFINE_MUTEX(mem_ctls_mutex);
45 static LIST_HEAD(mc_devices);
46
47 /*
48  * Used to lock EDAC MC to just one module, avoiding two drivers e. g.
49  *      apei/ghes and i7core_edac to be used at the same time.
50  */
51 static void const *edac_mc_owner;
52
53 static struct bus_type mc_bus[EDAC_MAX_MCS];
54
55 unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf,
56                                  unsigned len)
57 {
58         struct mem_ctl_info *mci = dimm->mci;
59         int i, n, count = 0;
60         char *p = buf;
61
62         for (i = 0; i < mci->n_layers; i++) {
63                 n = snprintf(p, len, "%s %d ",
64                               edac_layer_name[mci->layers[i].type],
65                               dimm->location[i]);
66                 p += n;
67                 len -= n;
68                 count += n;
69                 if (!len)
70                         break;
71         }
72
73         return count;
74 }
75
76 #ifdef CONFIG_EDAC_DEBUG
77
78 static void edac_mc_dump_channel(struct rank_info *chan)
79 {
80         edac_dbg(4, "  channel->chan_idx = %d\n", chan->chan_idx);
81         edac_dbg(4, "    channel = %p\n", chan);
82         edac_dbg(4, "    channel->csrow = %p\n", chan->csrow);
83         edac_dbg(4, "    channel->dimm = %p\n", chan->dimm);
84 }
85
86 static void edac_mc_dump_dimm(struct dimm_info *dimm, int number)
87 {
88         char location[80];
89
90         edac_dimm_info_location(dimm, location, sizeof(location));
91
92         edac_dbg(4, "%s%i: %smapped as virtual row %d, chan %d\n",
93                  dimm->mci->csbased ? "rank" : "dimm",
94                  number, location, dimm->csrow, dimm->cschannel);
95         edac_dbg(4, "  dimm = %p\n", dimm);
96         edac_dbg(4, "  dimm->label = '%s'\n", dimm->label);
97         edac_dbg(4, "  dimm->nr_pages = 0x%x\n", dimm->nr_pages);
98         edac_dbg(4, "  dimm->grain = %d\n", dimm->grain);
99         edac_dbg(4, "  dimm->nr_pages = 0x%x\n", dimm->nr_pages);
100 }
101
102 static void edac_mc_dump_csrow(struct csrow_info *csrow)
103 {
104         edac_dbg(4, "csrow->csrow_idx = %d\n", csrow->csrow_idx);
105         edac_dbg(4, "  csrow = %p\n", csrow);
106         edac_dbg(4, "  csrow->first_page = 0x%lx\n", csrow->first_page);
107         edac_dbg(4, "  csrow->last_page = 0x%lx\n", csrow->last_page);
108         edac_dbg(4, "  csrow->page_mask = 0x%lx\n", csrow->page_mask);
109         edac_dbg(4, "  csrow->nr_channels = %d\n", csrow->nr_channels);
110         edac_dbg(4, "  csrow->channels = %p\n", csrow->channels);
111         edac_dbg(4, "  csrow->mci = %p\n", csrow->mci);
112 }
113
114 static void edac_mc_dump_mci(struct mem_ctl_info *mci)
115 {
116         edac_dbg(3, "\tmci = %p\n", mci);
117         edac_dbg(3, "\tmci->mtype_cap = %lx\n", mci->mtype_cap);
118         edac_dbg(3, "\tmci->edac_ctl_cap = %lx\n", mci->edac_ctl_cap);
119         edac_dbg(3, "\tmci->edac_cap = %lx\n", mci->edac_cap);
120         edac_dbg(4, "\tmci->edac_check = %p\n", mci->edac_check);
121         edac_dbg(3, "\tmci->nr_csrows = %d, csrows = %p\n",
122                  mci->nr_csrows, mci->csrows);
123         edac_dbg(3, "\tmci->nr_dimms = %d, dimms = %p\n",
124                  mci->tot_dimms, mci->dimms);
125         edac_dbg(3, "\tdev = %p\n", mci->pdev);
126         edac_dbg(3, "\tmod_name:ctl_name = %s:%s\n",
127                  mci->mod_name, mci->ctl_name);
128         edac_dbg(3, "\tpvt_info = %p\n\n", mci->pvt_info);
129 }
130
131 #endif                          /* CONFIG_EDAC_DEBUG */
132
133 const char * const edac_mem_types[] = {
134         [MEM_EMPTY]     = "Empty csrow",
135         [MEM_RESERVED]  = "Reserved csrow type",
136         [MEM_UNKNOWN]   = "Unknown csrow type",
137         [MEM_FPM]       = "Fast page mode RAM",
138         [MEM_EDO]       = "Extended data out RAM",
139         [MEM_BEDO]      = "Burst Extended data out RAM",
140         [MEM_SDR]       = "Single data rate SDRAM",
141         [MEM_RDR]       = "Registered single data rate SDRAM",
142         [MEM_DDR]       = "Double data rate SDRAM",
143         [MEM_RDDR]      = "Registered Double data rate SDRAM",
144         [MEM_RMBS]      = "Rambus DRAM",
145         [MEM_DDR2]      = "Unbuffered DDR2 RAM",
146         [MEM_FB_DDR2]   = "Fully buffered DDR2",
147         [MEM_RDDR2]     = "Registered DDR2 RAM",
148         [MEM_XDR]       = "Rambus XDR",
149         [MEM_DDR3]      = "Unbuffered DDR3 RAM",
150         [MEM_RDDR3]     = "Registered DDR3 RAM",
151         [MEM_LRDDR3]    = "Load-Reduced DDR3 RAM",
152         [MEM_DDR4]      = "Unbuffered DDR4 RAM",
153         [MEM_RDDR4]     = "Registered DDR4 RAM",
154 };
155 EXPORT_SYMBOL_GPL(edac_mem_types);
156
157 /**
158  * edac_align_ptr - Prepares the pointer offsets for a single-shot allocation
159  * @p:          pointer to a pointer with the memory offset to be used. At
160  *              return, this will be incremented to point to the next offset
161  * @size:       Size of the data structure to be reserved
162  * @n_elems:    Number of elements that should be reserved
163  *
164  * If 'size' is a constant, the compiler will optimize this whole function
165  * down to either a no-op or the addition of a constant to the value of '*p'.
166  *
167  * The 'p' pointer is absolutely needed to keep the proper advancing
168  * further in memory to the proper offsets when allocating the struct along
169  * with its embedded structs, as edac_device_alloc_ctl_info() does it
170  * above, for example.
171  *
172  * At return, the pointer 'p' will be incremented to be used on a next call
173  * to this function.
174  */
175 void *edac_align_ptr(void **p, unsigned size, int n_elems)
176 {
177         unsigned align, r;
178         void *ptr = *p;
179
180         *p += size * n_elems;
181
182         /*
183          * 'p' can possibly be an unaligned item X such that sizeof(X) is
184          * 'size'.  Adjust 'p' so that its alignment is at least as
185          * stringent as what the compiler would provide for X and return
186          * the aligned result.
187          * Here we assume that the alignment of a "long long" is the most
188          * stringent alignment that the compiler will ever provide by default.
189          * As far as I know, this is a reasonable assumption.
190          */
191         if (size > sizeof(long))
192                 align = sizeof(long long);
193         else if (size > sizeof(int))
194                 align = sizeof(long);
195         else if (size > sizeof(short))
196                 align = sizeof(int);
197         else if (size > sizeof(char))
198                 align = sizeof(short);
199         else
200                 return (char *)ptr;
201
202         r = (unsigned long)p % align;
203
204         if (r == 0)
205                 return (char *)ptr;
206
207         *p += align - r;
208
209         return (void *)(((unsigned long)ptr) + align - r);
210 }
211
212 static void _edac_mc_free(struct mem_ctl_info *mci)
213 {
214         int i, chn, row;
215         struct csrow_info *csr;
216         const unsigned int tot_dimms = mci->tot_dimms;
217         const unsigned int tot_channels = mci->num_cschannel;
218         const unsigned int tot_csrows = mci->nr_csrows;
219
220         if (mci->dimms) {
221                 for (i = 0; i < tot_dimms; i++)
222                         kfree(mci->dimms[i]);
223                 kfree(mci->dimms);
224         }
225         if (mci->csrows) {
226                 for (row = 0; row < tot_csrows; row++) {
227                         csr = mci->csrows[row];
228                         if (csr) {
229                                 if (csr->channels) {
230                                         for (chn = 0; chn < tot_channels; chn++)
231                                                 kfree(csr->channels[chn]);
232                                         kfree(csr->channels);
233                                 }
234                                 kfree(csr);
235                         }
236                 }
237                 kfree(mci->csrows);
238         }
239         kfree(mci);
240 }
241
242 /**
243  * edac_mc_alloc: Allocate and partially fill a struct mem_ctl_info structure
244  * @mc_num:             Memory controller number
245  * @n_layers:           Number of MC hierarchy layers
246  * layers:              Describes each layer as seen by the Memory Controller
247  * @size_pvt:           size of private storage needed
248  *
249  *
250  * Everything is kmalloc'ed as one big chunk - more efficient.
251  * Only can be used if all structures have the same lifetime - otherwise
252  * you have to allocate and initialize your own structures.
253  *
254  * Use edac_mc_free() to free mc structures allocated by this function.
255  *
256  * NOTE: drivers handle multi-rank memories in different ways: in some
257  * drivers, one multi-rank memory stick is mapped as one entry, while, in
258  * others, a single multi-rank memory stick would be mapped into several
259  * entries. Currently, this function will allocate multiple struct dimm_info
260  * on such scenarios, as grouping the multiple ranks require drivers change.
261  *
262  * Returns:
263  *      On failure: NULL
264  *      On success: struct mem_ctl_info pointer
265  */
266 struct mem_ctl_info *edac_mc_alloc(unsigned mc_num,
267                                    unsigned n_layers,
268                                    struct edac_mc_layer *layers,
269                                    unsigned sz_pvt)
270 {
271         struct mem_ctl_info *mci;
272         struct edac_mc_layer *layer;
273         struct csrow_info *csr;
274         struct rank_info *chan;
275         struct dimm_info *dimm;
276         u32 *ce_per_layer[EDAC_MAX_LAYERS], *ue_per_layer[EDAC_MAX_LAYERS];
277         unsigned pos[EDAC_MAX_LAYERS];
278         unsigned size, tot_dimms = 1, count = 1;
279         unsigned tot_csrows = 1, tot_channels = 1, tot_errcount = 0;
280         void *pvt, *p, *ptr = NULL;
281         int i, j, row, chn, n, len, off;
282         bool per_rank = false;
283
284         BUG_ON(n_layers > EDAC_MAX_LAYERS || n_layers == 0);
285         /*
286          * Calculate the total amount of dimms and csrows/cschannels while
287          * in the old API emulation mode
288          */
289         for (i = 0; i < n_layers; i++) {
290                 tot_dimms *= layers[i].size;
291                 if (layers[i].is_virt_csrow)
292                         tot_csrows *= layers[i].size;
293                 else
294                         tot_channels *= layers[i].size;
295
296                 if (layers[i].type == EDAC_MC_LAYER_CHIP_SELECT)
297                         per_rank = true;
298         }
299
300         /* Figure out the offsets of the various items from the start of an mc
301          * structure.  We want the alignment of each item to be at least as
302          * stringent as what the compiler would provide if we could simply
303          * hardcode everything into a single struct.
304          */
305         mci = edac_align_ptr(&ptr, sizeof(*mci), 1);
306         layer = edac_align_ptr(&ptr, sizeof(*layer), n_layers);
307         for (i = 0; i < n_layers; i++) {
308                 count *= layers[i].size;
309                 edac_dbg(4, "errcount layer %d size %d\n", i, count);
310                 ce_per_layer[i] = edac_align_ptr(&ptr, sizeof(u32), count);
311                 ue_per_layer[i] = edac_align_ptr(&ptr, sizeof(u32), count);
312                 tot_errcount += 2 * count;
313         }
314
315         edac_dbg(4, "allocating %d error counters\n", tot_errcount);
316         pvt = edac_align_ptr(&ptr, sz_pvt, 1);
317         size = ((unsigned long)pvt) + sz_pvt;
318
319         edac_dbg(1, "allocating %u bytes for mci data (%d %s, %d csrows/channels)\n",
320                  size,
321                  tot_dimms,
322                  per_rank ? "ranks" : "dimms",
323                  tot_csrows * tot_channels);
324
325         mci = kzalloc(size, GFP_KERNEL);
326         if (mci == NULL)
327                 return NULL;
328
329         /* Adjust pointers so they point within the memory we just allocated
330          * rather than an imaginary chunk of memory located at address 0.
331          */
332         layer = (struct edac_mc_layer *)(((char *)mci) + ((unsigned long)layer));
333         for (i = 0; i < n_layers; i++) {
334                 mci->ce_per_layer[i] = (u32 *)((char *)mci + ((unsigned long)ce_per_layer[i]));
335                 mci->ue_per_layer[i] = (u32 *)((char *)mci + ((unsigned long)ue_per_layer[i]));
336         }
337         pvt = sz_pvt ? (((char *)mci) + ((unsigned long)pvt)) : NULL;
338
339         /* setup index and various internal pointers */
340         mci->mc_idx = mc_num;
341         mci->tot_dimms = tot_dimms;
342         mci->pvt_info = pvt;
343         mci->n_layers = n_layers;
344         mci->layers = layer;
345         memcpy(mci->layers, layers, sizeof(*layer) * n_layers);
346         mci->nr_csrows = tot_csrows;
347         mci->num_cschannel = tot_channels;
348         mci->csbased = per_rank;
349
350         /*
351          * Alocate and fill the csrow/channels structs
352          */
353         mci->csrows = kcalloc(tot_csrows, sizeof(*mci->csrows), GFP_KERNEL);
354         if (!mci->csrows)
355                 goto error;
356         for (row = 0; row < tot_csrows; row++) {
357                 csr = kzalloc(sizeof(**mci->csrows), GFP_KERNEL);
358                 if (!csr)
359                         goto error;
360                 mci->csrows[row] = csr;
361                 csr->csrow_idx = row;
362                 csr->mci = mci;
363                 csr->nr_channels = tot_channels;
364                 csr->channels = kcalloc(tot_channels, sizeof(*csr->channels),
365                                         GFP_KERNEL);
366                 if (!csr->channels)
367                         goto error;
368
369                 for (chn = 0; chn < tot_channels; chn++) {
370                         chan = kzalloc(sizeof(**csr->channels), GFP_KERNEL);
371                         if (!chan)
372                                 goto error;
373                         csr->channels[chn] = chan;
374                         chan->chan_idx = chn;
375                         chan->csrow = csr;
376                 }
377         }
378
379         /*
380          * Allocate and fill the dimm structs
381          */
382         mci->dimms  = kcalloc(tot_dimms, sizeof(*mci->dimms), GFP_KERNEL);
383         if (!mci->dimms)
384                 goto error;
385
386         memset(&pos, 0, sizeof(pos));
387         row = 0;
388         chn = 0;
389         for (i = 0; i < tot_dimms; i++) {
390                 chan = mci->csrows[row]->channels[chn];
391                 off = EDAC_DIMM_OFF(layer, n_layers, pos[0], pos[1], pos[2]);
392                 if (off < 0 || off >= tot_dimms) {
393                         edac_mc_printk(mci, KERN_ERR, "EDAC core bug: EDAC_DIMM_OFF is trying to do an illegal data access\n");
394                         goto error;
395                 }
396
397                 dimm = kzalloc(sizeof(**mci->dimms), GFP_KERNEL);
398                 if (!dimm)
399                         goto error;
400                 mci->dimms[off] = dimm;
401                 dimm->mci = mci;
402
403                 /*
404                  * Copy DIMM location and initialize it.
405                  */
406                 len = sizeof(dimm->label);
407                 p = dimm->label;
408                 n = snprintf(p, len, "mc#%u", mc_num);
409                 p += n;
410                 len -= n;
411                 for (j = 0; j < n_layers; j++) {
412                         n = snprintf(p, len, "%s#%u",
413                                      edac_layer_name[layers[j].type],
414                                      pos[j]);
415                         p += n;
416                         len -= n;
417                         dimm->location[j] = pos[j];
418
419                         if (len <= 0)
420                                 break;
421                 }
422
423                 /* Link it to the csrows old API data */
424                 chan->dimm = dimm;
425                 dimm->csrow = row;
426                 dimm->cschannel = chn;
427
428                 /* Increment csrow location */
429                 if (layers[0].is_virt_csrow) {
430                         chn++;
431                         if (chn == tot_channels) {
432                                 chn = 0;
433                                 row++;
434                         }
435                 } else {
436                         row++;
437                         if (row == tot_csrows) {
438                                 row = 0;
439                                 chn++;
440                         }
441                 }
442
443                 /* Increment dimm location */
444                 for (j = n_layers - 1; j >= 0; j--) {
445                         pos[j]++;
446                         if (pos[j] < layers[j].size)
447                                 break;
448                         pos[j] = 0;
449                 }
450         }
451
452         mci->op_state = OP_ALLOC;
453
454         return mci;
455
456 error:
457         _edac_mc_free(mci);
458
459         return NULL;
460 }
461 EXPORT_SYMBOL_GPL(edac_mc_alloc);
462
463 /**
464  * edac_mc_free
465  *      'Free' a previously allocated 'mci' structure
466  * @mci: pointer to a struct mem_ctl_info structure
467  */
468 void edac_mc_free(struct mem_ctl_info *mci)
469 {
470         edac_dbg(1, "\n");
471
472         /* If we're not yet registered with sysfs free only what was allocated
473          * in edac_mc_alloc().
474          */
475         if (!device_is_registered(&mci->dev)) {
476                 _edac_mc_free(mci);
477                 return;
478         }
479
480         /* the mci instance is freed here, when the sysfs object is dropped */
481         edac_unregister_sysfs(mci);
482 }
483 EXPORT_SYMBOL_GPL(edac_mc_free);
484
485
486 /**
487  * find_mci_by_dev
488  *
489  *      scan list of controllers looking for the one that manages
490  *      the 'dev' device
491  * @dev: pointer to a struct device related with the MCI
492  */
493 struct mem_ctl_info *find_mci_by_dev(struct device *dev)
494 {
495         struct mem_ctl_info *mci;
496         struct list_head *item;
497
498         edac_dbg(3, "\n");
499
500         list_for_each(item, &mc_devices) {
501                 mci = list_entry(item, struct mem_ctl_info, link);
502
503                 if (mci->pdev == dev)
504                         return mci;
505         }
506
507         return NULL;
508 }
509 EXPORT_SYMBOL_GPL(find_mci_by_dev);
510
511 /*
512  * handler for EDAC to check if NMI type handler has asserted interrupt
513  */
514 static int edac_mc_assert_error_check_and_clear(void)
515 {
516         int old_state;
517
518         if (edac_op_state == EDAC_OPSTATE_POLL)
519                 return 1;
520
521         old_state = edac_err_assert;
522         edac_err_assert = 0;
523
524         return old_state;
525 }
526
527 /*
528  * edac_mc_workq_function
529  *      performs the operation scheduled by a workq request
530  */
531 static void edac_mc_workq_function(struct work_struct *work_req)
532 {
533         struct delayed_work *d_work = to_delayed_work(work_req);
534         struct mem_ctl_info *mci = to_edac_mem_ctl_work(d_work);
535
536         mutex_lock(&mem_ctls_mutex);
537
538         /* if this control struct has movd to offline state, we are done */
539         if (mci->op_state == OP_OFFLINE) {
540                 mutex_unlock(&mem_ctls_mutex);
541                 return;
542         }
543
544         /* Only poll controllers that are running polled and have a check */
545         if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL))
546                 mci->edac_check(mci);
547
548         mutex_unlock(&mem_ctls_mutex);
549
550         /* Reschedule */
551         queue_delayed_work(edac_workqueue, &mci->work,
552                         msecs_to_jiffies(edac_mc_get_poll_msec()));
553 }
554
555 /*
556  * edac_mc_workq_setup
557  *      initialize a workq item for this mci
558  *      passing in the new delay period in msec
559  *
560  *      locking model:
561  *
562  *              called with the mem_ctls_mutex held
563  */
564 static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec,
565                                 bool init)
566 {
567         edac_dbg(0, "\n");
568
569         /* if this instance is not in the POLL state, then simply return */
570         if (mci->op_state != OP_RUNNING_POLL)
571                 return;
572
573         if (init)
574                 INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
575
576         mod_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
577 }
578
579 /*
580  * edac_mc_workq_teardown
581  *      stop the workq processing on this mci
582  *
583  *      locking model:
584  *
585  *              called WITHOUT lock held
586  */
587 static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
588 {
589         int status;
590
591         if (mci->op_state != OP_RUNNING_POLL)
592                 return;
593
594         status = cancel_delayed_work(&mci->work);
595         if (status == 0) {
596                 edac_dbg(0, "not canceled, flush the queue\n");
597
598                 /* workq instance might be running, wait for it */
599                 flush_workqueue(edac_workqueue);
600         }
601 }
602
603 /*
604  * edac_mc_reset_delay_period(unsigned long value)
605  *
606  *      user space has updated our poll period value, need to
607  *      reset our workq delays
608  */
609 void edac_mc_reset_delay_period(unsigned long value)
610 {
611         struct mem_ctl_info *mci;
612         struct list_head *item;
613
614         mutex_lock(&mem_ctls_mutex);
615
616         list_for_each(item, &mc_devices) {
617                 mci = list_entry(item, struct mem_ctl_info, link);
618
619                 edac_mc_workq_setup(mci, value, false);
620         }
621
622         mutex_unlock(&mem_ctls_mutex);
623 }
624
625
626
627 /* Return 0 on success, 1 on failure.
628  * Before calling this function, caller must
629  * assign a unique value to mci->mc_idx.
630  *
631  *      locking model:
632  *
633  *              called with the mem_ctls_mutex lock held
634  */
635 static int add_mc_to_global_list(struct mem_ctl_info *mci)
636 {
637         struct list_head *item, *insert_before;
638         struct mem_ctl_info *p;
639
640         insert_before = &mc_devices;
641
642         p = find_mci_by_dev(mci->pdev);
643         if (unlikely(p != NULL))
644                 goto fail0;
645
646         list_for_each(item, &mc_devices) {
647                 p = list_entry(item, struct mem_ctl_info, link);
648
649                 if (p->mc_idx >= mci->mc_idx) {
650                         if (unlikely(p->mc_idx == mci->mc_idx))
651                                 goto fail1;
652
653                         insert_before = item;
654                         break;
655                 }
656         }
657
658         list_add_tail_rcu(&mci->link, insert_before);
659         atomic_inc(&edac_handlers);
660         return 0;
661
662 fail0:
663         edac_printk(KERN_WARNING, EDAC_MC,
664                 "%s (%s) %s %s already assigned %d\n", dev_name(p->pdev),
665                 edac_dev_name(mci), p->mod_name, p->ctl_name, p->mc_idx);
666         return 1;
667
668 fail1:
669         edac_printk(KERN_WARNING, EDAC_MC,
670                 "bug in low-level driver: attempt to assign\n"
671                 "    duplicate mc_idx %d in %s()\n", p->mc_idx, __func__);
672         return 1;
673 }
674
675 static int del_mc_from_global_list(struct mem_ctl_info *mci)
676 {
677         int handlers = atomic_dec_return(&edac_handlers);
678         list_del_rcu(&mci->link);
679
680         /* these are for safe removal of devices from global list while
681          * NMI handlers may be traversing list
682          */
683         synchronize_rcu();
684         INIT_LIST_HEAD(&mci->link);
685
686         return handlers;
687 }
688
689 /**
690  * edac_mc_find: Search for a mem_ctl_info structure whose index is 'idx'.
691  *
692  * If found, return a pointer to the structure.
693  * Else return NULL.
694  *
695  * Caller must hold mem_ctls_mutex.
696  */
697 struct mem_ctl_info *edac_mc_find(int idx)
698 {
699         struct list_head *item;
700         struct mem_ctl_info *mci;
701
702         list_for_each(item, &mc_devices) {
703                 mci = list_entry(item, struct mem_ctl_info, link);
704
705                 if (mci->mc_idx >= idx) {
706                         if (mci->mc_idx == idx)
707                                 return mci;
708
709                         break;
710                 }
711         }
712
713         return NULL;
714 }
715 EXPORT_SYMBOL(edac_mc_find);
716
717 /**
718  * edac_mc_add_mc_with_groups: Insert the 'mci' structure into the mci
719  *      global list and create sysfs entries associated with mci structure
720  * @mci: pointer to the mci structure to be added to the list
721  * @groups: optional attribute groups for the driver-specific sysfs entries
722  *
723  * Return:
724  *      0       Success
725  *      !0      Failure
726  */
727
728 /* FIXME - should a warning be printed if no error detection? correction? */
729 int edac_mc_add_mc_with_groups(struct mem_ctl_info *mci,
730                                const struct attribute_group **groups)
731 {
732         int ret = -EINVAL;
733         edac_dbg(0, "\n");
734
735         if (mci->mc_idx >= EDAC_MAX_MCS) {
736                 pr_warn_once("Too many memory controllers: %d\n", mci->mc_idx);
737                 return -ENODEV;
738         }
739
740 #ifdef CONFIG_EDAC_DEBUG
741         if (edac_debug_level >= 3)
742                 edac_mc_dump_mci(mci);
743
744         if (edac_debug_level >= 4) {
745                 int i;
746
747                 for (i = 0; i < mci->nr_csrows; i++) {
748                         struct csrow_info *csrow = mci->csrows[i];
749                         u32 nr_pages = 0;
750                         int j;
751
752                         for (j = 0; j < csrow->nr_channels; j++)
753                                 nr_pages += csrow->channels[j]->dimm->nr_pages;
754                         if (!nr_pages)
755                                 continue;
756                         edac_mc_dump_csrow(csrow);
757                         for (j = 0; j < csrow->nr_channels; j++)
758                                 if (csrow->channels[j]->dimm->nr_pages)
759                                         edac_mc_dump_channel(csrow->channels[j]);
760                 }
761                 for (i = 0; i < mci->tot_dimms; i++)
762                         if (mci->dimms[i]->nr_pages)
763                                 edac_mc_dump_dimm(mci->dimms[i], i);
764         }
765 #endif
766         mutex_lock(&mem_ctls_mutex);
767
768         if (edac_mc_owner && edac_mc_owner != mci->mod_name) {
769                 ret = -EPERM;
770                 goto fail0;
771         }
772
773         if (add_mc_to_global_list(mci))
774                 goto fail0;
775
776         /* set load time so that error rate can be tracked */
777         mci->start_time = jiffies;
778
779         mci->bus = &mc_bus[mci->mc_idx];
780
781         if (edac_create_sysfs_mci_device(mci, groups)) {
782                 edac_mc_printk(mci, KERN_WARNING,
783                         "failed to create sysfs device\n");
784                 goto fail1;
785         }
786
787         /* If there IS a check routine, then we are running POLLED */
788         if (mci->edac_check != NULL) {
789                 /* This instance is NOW RUNNING */
790                 mci->op_state = OP_RUNNING_POLL;
791
792                 edac_mc_workq_setup(mci, edac_mc_get_poll_msec(), true);
793         } else {
794                 mci->op_state = OP_RUNNING_INTERRUPT;
795         }
796
797         /* Report action taken */
798         edac_mc_printk(mci, KERN_INFO,
799                 "Giving out device to module %s controller %s: DEV %s (%s)\n",
800                 mci->mod_name, mci->ctl_name, mci->dev_name,
801                 edac_op_state_to_string(mci->op_state));
802
803         edac_mc_owner = mci->mod_name;
804
805         mutex_unlock(&mem_ctls_mutex);
806         return 0;
807
808 fail1:
809         del_mc_from_global_list(mci);
810
811 fail0:
812         mutex_unlock(&mem_ctls_mutex);
813         return ret;
814 }
815 EXPORT_SYMBOL_GPL(edac_mc_add_mc_with_groups);
816
817 /**
818  * edac_mc_del_mc: Remove sysfs entries for specified mci structure and
819  *                 remove mci structure from global list
820  * @pdev: Pointer to 'struct device' representing mci structure to remove.
821  *
822  * Return pointer to removed mci structure, or NULL if device not found.
823  */
824 struct mem_ctl_info *edac_mc_del_mc(struct device *dev)
825 {
826         struct mem_ctl_info *mci;
827
828         edac_dbg(0, "\n");
829
830         mutex_lock(&mem_ctls_mutex);
831
832         /* find the requested mci struct in the global list */
833         mci = find_mci_by_dev(dev);
834         if (mci == NULL) {
835                 mutex_unlock(&mem_ctls_mutex);
836                 return NULL;
837         }
838
839         if (!del_mc_from_global_list(mci))
840                 edac_mc_owner = NULL;
841         mutex_unlock(&mem_ctls_mutex);
842
843         /* flush workq processes */
844         edac_mc_workq_teardown(mci);
845
846         /* marking MCI offline */
847         mci->op_state = OP_OFFLINE;
848
849         /* remove from sysfs */
850         edac_remove_sysfs_mci_device(mci);
851
852         edac_printk(KERN_INFO, EDAC_MC,
853                 "Removed device %d for %s %s: DEV %s\n", mci->mc_idx,
854                 mci->mod_name, mci->ctl_name, edac_dev_name(mci));
855
856         return mci;
857 }
858 EXPORT_SYMBOL_GPL(edac_mc_del_mc);
859
860 static void edac_mc_scrub_block(unsigned long page, unsigned long offset,
861                                 u32 size)
862 {
863         struct page *pg;
864         void *virt_addr;
865         unsigned long flags = 0;
866
867         edac_dbg(3, "\n");
868
869         /* ECC error page was not in our memory. Ignore it. */
870         if (!pfn_valid(page))
871                 return;
872
873         /* Find the actual page structure then map it and fix */
874         pg = pfn_to_page(page);
875
876         if (PageHighMem(pg))
877                 local_irq_save(flags);
878
879         virt_addr = kmap_atomic(pg);
880
881         /* Perform architecture specific atomic scrub operation */
882         edac_atomic_scrub(virt_addr + offset, size);
883
884         /* Unmap and complete */
885         kunmap_atomic(virt_addr);
886
887         if (PageHighMem(pg))
888                 local_irq_restore(flags);
889 }
890
891 /* FIXME - should return -1 */
892 int edac_mc_find_csrow_by_page(struct mem_ctl_info *mci, unsigned long page)
893 {
894         struct csrow_info **csrows = mci->csrows;
895         int row, i, j, n;
896
897         edac_dbg(1, "MC%d: 0x%lx\n", mci->mc_idx, page);
898         row = -1;
899
900         for (i = 0; i < mci->nr_csrows; i++) {
901                 struct csrow_info *csrow = csrows[i];
902                 n = 0;
903                 for (j = 0; j < csrow->nr_channels; j++) {
904                         struct dimm_info *dimm = csrow->channels[j]->dimm;
905                         n += dimm->nr_pages;
906                 }
907                 if (n == 0)
908                         continue;
909
910                 edac_dbg(3, "MC%d: first(0x%lx) page(0x%lx) last(0x%lx) mask(0x%lx)\n",
911                          mci->mc_idx,
912                          csrow->first_page, page, csrow->last_page,
913                          csrow->page_mask);
914
915                 if ((page >= csrow->first_page) &&
916                     (page <= csrow->last_page) &&
917                     ((page & csrow->page_mask) ==
918                      (csrow->first_page & csrow->page_mask))) {
919                         row = i;
920                         break;
921                 }
922         }
923
924         if (row == -1)
925                 edac_mc_printk(mci, KERN_ERR,
926                         "could not look up page error address %lx\n",
927                         (unsigned long)page);
928
929         return row;
930 }
931 EXPORT_SYMBOL_GPL(edac_mc_find_csrow_by_page);
932
933 const char *edac_layer_name[] = {
934         [EDAC_MC_LAYER_BRANCH] = "branch",
935         [EDAC_MC_LAYER_CHANNEL] = "channel",
936         [EDAC_MC_LAYER_SLOT] = "slot",
937         [EDAC_MC_LAYER_CHIP_SELECT] = "csrow",
938         [EDAC_MC_LAYER_ALL_MEM] = "memory",
939 };
940 EXPORT_SYMBOL_GPL(edac_layer_name);
941
942 static void edac_inc_ce_error(struct mem_ctl_info *mci,
943                               bool enable_per_layer_report,
944                               const int pos[EDAC_MAX_LAYERS],
945                               const u16 count)
946 {
947         int i, index = 0;
948
949         mci->ce_mc += count;
950
951         if (!enable_per_layer_report) {
952                 mci->ce_noinfo_count += count;
953                 return;
954         }
955
956         for (i = 0; i < mci->n_layers; i++) {
957                 if (pos[i] < 0)
958                         break;
959                 index += pos[i];
960                 mci->ce_per_layer[i][index] += count;
961
962                 if (i < mci->n_layers - 1)
963                         index *= mci->layers[i + 1].size;
964         }
965 }
966
967 static void edac_inc_ue_error(struct mem_ctl_info *mci,
968                                     bool enable_per_layer_report,
969                                     const int pos[EDAC_MAX_LAYERS],
970                                     const u16 count)
971 {
972         int i, index = 0;
973
974         mci->ue_mc += count;
975
976         if (!enable_per_layer_report) {
977                 mci->ce_noinfo_count += count;
978                 return;
979         }
980
981         for (i = 0; i < mci->n_layers; i++) {
982                 if (pos[i] < 0)
983                         break;
984                 index += pos[i];
985                 mci->ue_per_layer[i][index] += count;
986
987                 if (i < mci->n_layers - 1)
988                         index *= mci->layers[i + 1].size;
989         }
990 }
991
992 static void edac_ce_error(struct mem_ctl_info *mci,
993                           const u16 error_count,
994                           const int pos[EDAC_MAX_LAYERS],
995                           const char *msg,
996                           const char *location,
997                           const char *label,
998                           const char *detail,
999                           const char *other_detail,
1000                           const bool enable_per_layer_report,
1001                           const unsigned long page_frame_number,
1002                           const unsigned long offset_in_page,
1003                           long grain)
1004 {
1005         unsigned long remapped_page;
1006         char *msg_aux = "";
1007
1008         if (*msg)
1009                 msg_aux = " ";
1010
1011         if (edac_mc_get_log_ce()) {
1012                 if (other_detail && *other_detail)
1013                         edac_mc_printk(mci, KERN_WARNING,
1014                                        "%d CE %s%son %s (%s %s - %s)\n",
1015                                        error_count, msg, msg_aux, label,
1016                                        location, detail, other_detail);
1017                 else
1018                         edac_mc_printk(mci, KERN_WARNING,
1019                                        "%d CE %s%son %s (%s %s)\n",
1020                                        error_count, msg, msg_aux, label,
1021                                        location, detail);
1022         }
1023         edac_inc_ce_error(mci, enable_per_layer_report, pos, error_count);
1024
1025         if (mci->scrub_mode == SCRUB_SW_SRC) {
1026                 /*
1027                         * Some memory controllers (called MCs below) can remap
1028                         * memory so that it is still available at a different
1029                         * address when PCI devices map into memory.
1030                         * MC's that can't do this, lose the memory where PCI
1031                         * devices are mapped. This mapping is MC-dependent
1032                         * and so we call back into the MC driver for it to
1033                         * map the MC page to a physical (CPU) page which can
1034                         * then be mapped to a virtual page - which can then
1035                         * be scrubbed.
1036                         */
1037                 remapped_page = mci->ctl_page_to_phys ?
1038                         mci->ctl_page_to_phys(mci, page_frame_number) :
1039                         page_frame_number;
1040
1041                 edac_mc_scrub_block(remapped_page,
1042                                         offset_in_page, grain);
1043         }
1044 }
1045
1046 static void edac_ue_error(struct mem_ctl_info *mci,
1047                           const u16 error_count,
1048                           const int pos[EDAC_MAX_LAYERS],
1049                           const char *msg,
1050                           const char *location,
1051                           const char *label,
1052                           const char *detail,
1053                           const char *other_detail,
1054                           const bool enable_per_layer_report)
1055 {
1056         char *msg_aux = "";
1057
1058         if (*msg)
1059                 msg_aux = " ";
1060
1061         if (edac_mc_get_log_ue()) {
1062                 if (other_detail && *other_detail)
1063                         edac_mc_printk(mci, KERN_WARNING,
1064                                        "%d UE %s%son %s (%s %s - %s)\n",
1065                                        error_count, msg, msg_aux, label,
1066                                        location, detail, other_detail);
1067                 else
1068                         edac_mc_printk(mci, KERN_WARNING,
1069                                        "%d UE %s%son %s (%s %s)\n",
1070                                        error_count, msg, msg_aux, label,
1071                                        location, detail);
1072         }
1073
1074         if (edac_mc_get_panic_on_ue()) {
1075                 if (other_detail && *other_detail)
1076                         panic("UE %s%son %s (%s%s - %s)\n",
1077                               msg, msg_aux, label, location, detail, other_detail);
1078                 else
1079                         panic("UE %s%son %s (%s%s)\n",
1080                               msg, msg_aux, label, location, detail);
1081         }
1082
1083         edac_inc_ue_error(mci, enable_per_layer_report, pos, error_count);
1084 }
1085
1086 /**
1087  * edac_raw_mc_handle_error - reports a memory event to userspace without doing
1088  *                            anything to discover the error location
1089  *
1090  * @type:               severity of the error (CE/UE/Fatal)
1091  * @mci:                a struct mem_ctl_info pointer
1092  * @e:                  error description
1093  *
1094  * This raw function is used internally by edac_mc_handle_error(). It should
1095  * only be called directly when the hardware error come directly from BIOS,
1096  * like in the case of APEI GHES driver.
1097  */
1098 void edac_raw_mc_handle_error(const enum hw_event_mc_err_type type,
1099                               struct mem_ctl_info *mci,
1100                               struct edac_raw_error_desc *e)
1101 {
1102         char detail[80];
1103         int pos[EDAC_MAX_LAYERS] = { e->top_layer, e->mid_layer, e->low_layer };
1104
1105         /* Memory type dependent details about the error */
1106         if (type == HW_EVENT_ERR_CORRECTED) {
1107                 snprintf(detail, sizeof(detail),
1108                         "page:0x%lx offset:0x%lx grain:%ld syndrome:0x%lx",
1109                         e->page_frame_number, e->offset_in_page,
1110                         e->grain, e->syndrome);
1111                 edac_ce_error(mci, e->error_count, pos, e->msg, e->location, e->label,
1112                               detail, e->other_detail, e->enable_per_layer_report,
1113                               e->page_frame_number, e->offset_in_page, e->grain);
1114         } else {
1115                 snprintf(detail, sizeof(detail),
1116                         "page:0x%lx offset:0x%lx grain:%ld",
1117                         e->page_frame_number, e->offset_in_page, e->grain);
1118
1119                 edac_ue_error(mci, e->error_count, pos, e->msg, e->location, e->label,
1120                               detail, e->other_detail, e->enable_per_layer_report);
1121         }
1122
1123
1124 }
1125 EXPORT_SYMBOL_GPL(edac_raw_mc_handle_error);
1126
1127 /**
1128  * edac_mc_handle_error - reports a memory event to userspace
1129  *
1130  * @type:               severity of the error (CE/UE/Fatal)
1131  * @mci:                a struct mem_ctl_info pointer
1132  * @error_count:        Number of errors of the same type
1133  * @page_frame_number:  mem page where the error occurred
1134  * @offset_in_page:     offset of the error inside the page
1135  * @syndrome:           ECC syndrome
1136  * @top_layer:          Memory layer[0] position
1137  * @mid_layer:          Memory layer[1] position
1138  * @low_layer:          Memory layer[2] position
1139  * @msg:                Message meaningful to the end users that
1140  *                      explains the event
1141  * @other_detail:       Technical details about the event that
1142  *                      may help hardware manufacturers and
1143  *                      EDAC developers to analyse the event
1144  */
1145 void edac_mc_handle_error(const enum hw_event_mc_err_type type,
1146                           struct mem_ctl_info *mci,
1147                           const u16 error_count,
1148                           const unsigned long page_frame_number,
1149                           const unsigned long offset_in_page,
1150                           const unsigned long syndrome,
1151                           const int top_layer,
1152                           const int mid_layer,
1153                           const int low_layer,
1154                           const char *msg,
1155                           const char *other_detail)
1156 {
1157         char *p;
1158         int row = -1, chan = -1;
1159         int pos[EDAC_MAX_LAYERS] = { top_layer, mid_layer, low_layer };
1160         int i, n_labels = 0;
1161         u8 grain_bits;
1162         struct edac_raw_error_desc *e = &mci->error_desc;
1163
1164         edac_dbg(3, "MC%d\n", mci->mc_idx);
1165
1166         /* Fills the error report buffer */
1167         memset(e, 0, sizeof (*e));
1168         e->error_count = error_count;
1169         e->top_layer = top_layer;
1170         e->mid_layer = mid_layer;
1171         e->low_layer = low_layer;
1172         e->page_frame_number = page_frame_number;
1173         e->offset_in_page = offset_in_page;
1174         e->syndrome = syndrome;
1175         e->msg = msg;
1176         e->other_detail = other_detail;
1177
1178         /*
1179          * Check if the event report is consistent and if the memory
1180          * location is known. If it is known, enable_per_layer_report will be
1181          * true, the DIMM(s) label info will be filled and the per-layer
1182          * error counters will be incremented.
1183          */
1184         for (i = 0; i < mci->n_layers; i++) {
1185                 if (pos[i] >= (int)mci->layers[i].size) {
1186
1187                         edac_mc_printk(mci, KERN_ERR,
1188                                        "INTERNAL ERROR: %s value is out of range (%d >= %d)\n",
1189                                        edac_layer_name[mci->layers[i].type],
1190                                        pos[i], mci->layers[i].size);
1191                         /*
1192                          * Instead of just returning it, let's use what's
1193                          * known about the error. The increment routines and
1194                          * the DIMM filter logic will do the right thing by
1195                          * pointing the likely damaged DIMMs.
1196                          */
1197                         pos[i] = -1;
1198                 }
1199                 if (pos[i] >= 0)
1200                         e->enable_per_layer_report = true;
1201         }
1202
1203         /*
1204          * Get the dimm label/grain that applies to the match criteria.
1205          * As the error algorithm may not be able to point to just one memory
1206          * stick, the logic here will get all possible labels that could
1207          * pottentially be affected by the error.
1208          * On FB-DIMM memory controllers, for uncorrected errors, it is common
1209          * to have only the MC channel and the MC dimm (also called "branch")
1210          * but the channel is not known, as the memory is arranged in pairs,
1211          * where each memory belongs to a separate channel within the same
1212          * branch.
1213          */
1214         p = e->label;
1215         *p = '\0';
1216
1217         for (i = 0; i < mci->tot_dimms; i++) {
1218                 struct dimm_info *dimm = mci->dimms[i];
1219
1220                 if (top_layer >= 0 && top_layer != dimm->location[0])
1221                         continue;
1222                 if (mid_layer >= 0 && mid_layer != dimm->location[1])
1223                         continue;
1224                 if (low_layer >= 0 && low_layer != dimm->location[2])
1225                         continue;
1226
1227                 /* get the max grain, over the error match range */
1228                 if (dimm->grain > e->grain)
1229                         e->grain = dimm->grain;
1230
1231                 /*
1232                  * If the error is memory-controller wide, there's no need to
1233                  * seek for the affected DIMMs because the whole
1234                  * channel/memory controller/...  may be affected.
1235                  * Also, don't show errors for empty DIMM slots.
1236                  */
1237                 if (e->enable_per_layer_report && dimm->nr_pages) {
1238                         if (n_labels >= EDAC_MAX_LABELS) {
1239                                 e->enable_per_layer_report = false;
1240                                 break;
1241                         }
1242                         n_labels++;
1243                         if (p != e->label) {
1244                                 strcpy(p, OTHER_LABEL);
1245                                 p += strlen(OTHER_LABEL);
1246                         }
1247                         strcpy(p, dimm->label);
1248                         p += strlen(p);
1249                         *p = '\0';
1250
1251                         /*
1252                          * get csrow/channel of the DIMM, in order to allow
1253                          * incrementing the compat API counters
1254                          */
1255                         edac_dbg(4, "%s csrows map: (%d,%d)\n",
1256                                  mci->csbased ? "rank" : "dimm",
1257                                  dimm->csrow, dimm->cschannel);
1258                         if (row == -1)
1259                                 row = dimm->csrow;
1260                         else if (row >= 0 && row != dimm->csrow)
1261                                 row = -2;
1262
1263                         if (chan == -1)
1264                                 chan = dimm->cschannel;
1265                         else if (chan >= 0 && chan != dimm->cschannel)
1266                                 chan = -2;
1267                 }
1268         }
1269
1270         if (!e->enable_per_layer_report) {
1271                 strcpy(e->label, "any memory");
1272         } else {
1273                 edac_dbg(4, "csrow/channel to increment: (%d,%d)\n", row, chan);
1274                 if (p == e->label)
1275                         strcpy(e->label, "unknown memory");
1276                 if (type == HW_EVENT_ERR_CORRECTED) {
1277                         if (row >= 0) {
1278                                 mci->csrows[row]->ce_count += error_count;
1279                                 if (chan >= 0)
1280                                         mci->csrows[row]->channels[chan]->ce_count += error_count;
1281                         }
1282                 } else
1283                         if (row >= 0)
1284                                 mci->csrows[row]->ue_count += error_count;
1285         }
1286
1287         /* Fill the RAM location data */
1288         p = e->location;
1289
1290         for (i = 0; i < mci->n_layers; i++) {
1291                 if (pos[i] < 0)
1292                         continue;
1293
1294                 p += sprintf(p, "%s:%d ",
1295                              edac_layer_name[mci->layers[i].type],
1296                              pos[i]);
1297         }
1298         if (p > e->location)
1299                 *(p - 1) = '\0';
1300
1301         /* Report the error via the trace interface */
1302         grain_bits = fls_long(e->grain) + 1;
1303         trace_mc_event(type, e->msg, e->label, e->error_count,
1304                        mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer,
1305                        (e->page_frame_number << PAGE_SHIFT) | e->offset_in_page,
1306                        grain_bits, e->syndrome, e->other_detail);
1307
1308         edac_raw_mc_handle_error(type, mci, e);
1309 }
1310 EXPORT_SYMBOL_GPL(edac_mc_handle_error);