aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/edac/cpc925_edac.c
blob: 837ad8f85b48e1197dfd4e3f72a7a4340dd432bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
/*
 * cpc925_edac.c, EDAC driver for IBM CPC925 Bridge and Memory Controller.
 *
 * Copyright (c) 2008 Wind River Systems, Inc.
 *
 * Authors:	Cao Qingtao <qingtao.cao@windriver.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/edac.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/gfp.h>

#include "edac_core.h"
#include "edac_module.h"

#define CPC925_EDAC_REVISION	" Ver: 1.0.0 " __DATE__
#define CPC925_EDAC_MOD_STR	"cpc925_edac"

#define cpc925_printk(level, fmt, arg...) \
	edac_printk(level, "CPC925", fmt, ##arg)

#define cpc925_mc_printk(mci, level, fmt, arg...) \
	edac_mc_chipset_printk(mci, level, "CPC925", fmt, ##arg)

/*
 * CPC925 registers are of 32 bits with bit0 defined at the
 * most significant bit and bit31 at that of least significant.
 */
#define CPC925_BITS_PER_REG	32
#define CPC925_BIT(nr)		(1UL << (CPC925_BITS_PER_REG - 1 - nr))

/*
 * EDAC device names for the error detections of
 * CPU Interface and Hypertransport Link.
 */
#define CPC925_CPU_ERR_DEV	"cpu"
#define CPC925_HT_LINK_DEV	"htlink"

/* Suppose DDR Refresh cycle is 15.6 microsecond */
#define CPC925_REF_FREQ		0xFA69
#define CPC925_SCRUB_BLOCK_SIZE 64	/* bytes */
#define CPC925_NR_CSROWS	8

/*
 * All registers and bits definitions are taken from
 * "CPC925 Bridge and Memory Controller User Manual, SA14-2761-02".
 */

/*
 * CPU and Memory Controller Registers
 */
/************************************************************
 *	Processor Interface Exception Mask Register (APIMASK)
 ************************************************************/
#define REG_APIMASK_OFFSET	0x30070
enum apimask_bits {
	APIMASK_DART	= CPC925_BIT(0), /* DART Exception */
	APIMASK_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
	APIMASK_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
	APIMASK_STAT	= CPC925_BIT(3), /* Status Exception */
	APIMASK_DERR	= CPC925_BIT(4), /* Data Error Exception */
	APIMASK_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
	APIMASK_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
					 /* BIT(7) Reserved */
	APIMASK_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
	APIMASK_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
	APIMASK_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
	APIMASK_ECC_CE_L = CPC925_BIT(11), /* CECC lower */

	CPU_MASK_ENABLE = (APIMASK_DART | APIMASK_ADI0 | APIMASK_ADI1 |
			   APIMASK_STAT | APIMASK_DERR | APIMASK_ADRS0 |
			   APIMASK_ADRS1),
	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
};

/************************************************************
 *	Processor Interface Exception Register (APIEXCP)
 ************************************************************/
#define REG_APIEXCP_OFFSET	0x30060
enum apiexcp_bits {
	APIEXCP_DART	= CPC925_BIT(0), /* DART Exception */
	APIEXCP_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
	APIEXCP_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
	APIEXCP_STAT	= CPC925_BIT(3), /* Status Exception */
	APIEXCP_DERR	= CPC925_BIT(4), /* Data Error Exception */
	APIEXCP_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
	APIEXCP_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
					 /* BIT(7) Reserved */
	APIEXCP_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
	APIEXCP_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
	APIEXCP_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
	APIEXCP_ECC_CE_L = CPC925_BIT(11), /* CECC lower */

	CPU_EXCP_DETECTED = (APIEXCP_DART | APIEXCP_ADI0 | APIEXCP_ADI1 |
			     APIEXCP_STAT | APIEXCP_DERR | APIEXCP_ADRS0 |
			     APIEXCP_ADRS1),
	UECC_EXCP_DETECTED = (APIEXCP_ECC_UE_H | APIEXCP_ECC_UE_L),
	CECC_EXCP_DETECTED = (APIEXCP_ECC_CE_H | APIEXCP_ECC_CE_L),
	ECC_EXCP_DETECTED = (UECC_EXCP_DETECTED | CECC_EXCP_DETECTED),
};

/************************************************************
 *	Memory Bus Configuration Register (MBCR)
************************************************************/
#define REG_MBCR_OFFSET		0x2190
#define MBCR_64BITCFG_SHIFT	23
#define MBCR_64BITCFG_MASK	(1UL << MBCR_64BITCFG_SHIFT)
#define MBCR_64BITBUS_SHIFT	22
#define MBCR_64BITBUS_MASK	(1UL << MBCR_64BITBUS_SHIFT)

/************************************************************
 *	Memory Bank Mode Register (MBMR)
************************************************************/
#define REG_MBMR_OFFSET		0x21C0
#define MBMR_MODE_MAX_VALUE	0xF
#define MBMR_MODE_SHIFT		25
#define MBMR_MODE_MASK		(MBMR_MODE_MAX_VALUE << MBMR_MODE_SHIFT)
#define MBMR_BBA_SHIFT		24
#define MBMR_BBA_MASK		(1UL << MBMR_BBA_SHIFT)

/************************************************************
 *	Memory Bank Boundary Address Register (MBBAR)
 ************************************************************/
#define REG_MBBAR_OFFSET	0x21D0
#define MBBAR_BBA_MAX_VALUE	0xFF
#define MBBAR_BBA_SHIFT		24
#define MBBAR_BBA_MASK		(MBBAR_BBA_MAX_VALUE << MBBAR_BBA_SHIFT)

/************************************************************
 *	Memory Scrub Control Register (MSCR)
 ************************************************************/
#define REG_MSCR_OFFSET		0x2400
#define MSCR_SCRUB_MOD_MASK	0xC0000000 /* scrub_mod - bit0:1*/
#define MSCR_BACKGR_SCRUB	0x40000000 /* 01 */
#define MSCR_SI_SHIFT		16 	/* si - bit8:15*/
#define MSCR_SI_MAX_VALUE	0xFF
#define MSCR_SI_MASK		(MSCR_SI_MAX_VALUE << MSCR_SI_SHIFT)

/************************************************************
 *	Memory Scrub Range Start Register (MSRSR)
 ************************************************************/
#define REG_MSRSR_OFFSET	0x2410

/************************************************************
 *	Memory Scrub Range End Register (MSRER)
 ************************************************************/
#define REG_MSRER_OFFSET	0x2420

/************************************************************
 *	Memory Scrub Pattern Register (MSPR)
 ************************************************************/
#define REG_MSPR_OFFSET		0x2430

/************************************************************
 *	Memory Check Control Register (MCCR)
 ************************************************************/
#define REG_MCCR_OFFSET		0x2440
enum mccr_bits {
	MCCR_ECC_EN	= CPC925_BIT(0), /* ECC high and low check */
};

/************************************************************
 *	Memory Check Range End Register (MCRER)
 ************************************************************/
#define REG_MCRER_OFFSET	0x2450

/************************************************************
 *	Memory Error Address Register (MEAR)
 ************************************************************/
#define REG_MEAR_OFFSET		0x2460
#define MEAR_BCNT_MAX_VALUE	0x3
#define MEAR_BCNT_SHIFT		30
#define MEAR_BCNT_MASK		(MEAR_BCNT_MAX_VALUE << MEAR_BCNT_SHIFT)
#define MEAR_RANK_MAX_VALUE	0x7
#define MEAR_RANK_SHIFT		27
#define MEAR_RANK_MASK		(MEAR_RANK_MAX_VALUE << MEAR_RANK_SHIFT)
#define MEAR_COL_MAX_VALUE	0x7FF
#define MEAR_COL_SHIFT		16
#define MEAR_COL_MASK		(MEAR_COL_MAX_VALUE << MEAR_COL_SHIFT)
#define MEAR_BANK_MAX_VALUE	0x3
#define MEAR_BANK_SHIFT		14
#define MEAR_BANK_MASK		(MEAR_BANK_MAX_VALUE << MEAR_BANK_SHIFT)
#define MEAR_ROW_MASK		0x00003FFF

/************************************************************
 *	Memory Error Syndrome Register (MESR)
 ************************************************************/
#define REG_MESR_OFFSET		0x2470
#define MESR_ECC_SYN_H_MASK	0xFF00
#define MESR_ECC_SYN_L_MASK	0x00FF

/************************************************************
 *	Memory Mode Control Register (MMCR)
 ************************************************************/
#define REG_MMCR_OFFSET		0x2500
enum mmcr_bits {
	MMCR_REG_DIMM_MODE = CPC925_BIT(3),
};

/*
 * HyperTransport Link Registers
 */
/************************************************************
 *  Error Handling/Enumeration Scratch Pad Register (ERRCTRL)
 ************************************************************/
#define REG_ERRCTRL_OFFSET	0x70140
enum errctrl_bits {			 /* nonfatal interrupts for */
	ERRCTRL_SERR_NF	= CPC925_BIT(0), /* system error */
	ERRCTRL_CRC_NF	= CPC925_BIT(1), /* CRC error */
	ERRCTRL_RSP_NF	= CPC925_BIT(2), /* Response error */
	ERRCTRL_EOC_NF	= CPC925_BIT(3), /* End-Of-Chain error */
	ERRCTRL_OVF_NF	= CPC925_BIT(4), /* Overflow error */
	ERRCTRL_PROT_NF	= CPC925_BIT(5), /* Protocol error */

	ERRCTRL_RSP_ERR	= CPC925_BIT(6), /* Response error received */
	ERRCTRL_CHN_FAL = CPC925_BIT(7), /* Sync flooding detected */

	HT_ERRCTRL_ENABLE = (ERRCTRL_SERR_NF | ERRCTRL_CRC_NF |
			     ERRCTRL_RSP_NF | ERRCTRL_EOC_NF |
			     ERRCTRL_OVF_NF | ERRCTRL_PROT_NF),
	HT_ERRCTRL_DETECTED = (ERRCTRL_RSP_ERR | ERRCTRL_CHN_FAL),
};

/************************************************************
 *  Link Configuration and Link Control Register (LINKCTRL)
 ************************************************************/
#define REG_LINKCTRL_OFFSET	0x70110
enum linkctrl_bits {
	LINKCTRL_CRC_ERR	= (CPC925_BIT(22) | CPC925_BIT(23)),
	LINKCTRL_LINK_FAIL	= CPC925_BIT(27),

	HT_LINKCTRL_DETECTED	= (LINKCTRL_CRC_ERR | LINKCTRL_LINK_FAIL),
};

/************************************************************
 *  Link FreqCap/Error/Freq/Revision ID Register (LINKERR)
 ************************************************************/
#define REG_LINKERR_OFFSET	0x70120
enum linkerr_bits {
	LINKERR_EOC_ERR		= CPC925_BIT(17), /* End-Of-Chain error */
	LINKERR_OVF_ERR		= CPC925_BIT(18), /* Receive Buffer Overflow */
	LINKERR_PROT_ERR	= CPC925_BIT(19), /* Protocol error */

	HT_LINKERR_DETECTED	= (LINKERR_EOC_ERR | LINKERR_OVF_ERR |
				   LINKERR_PROT_ERR),
};

/************************************************************
 *	Bridge Control Register (BRGCTRL)
 ************************************************************/
#define REG_BRGCTRL_OFFSET	0x70300
enum brgctrl_bits {
	BRGCTRL_DETSERR = CPC925_BIT(0), /* SERR on Secondary Bus */
	BRGCTRL_SECBUSRESET = CPC925_BIT(9), /* Secondary Bus Reset */
};

/* Private structure for edac memory controller */
struct cpc925_mc_pdata {
	void __iomem *vbase;
	unsigned long total_mem;
	const char *name;
	int edac_idx;
};

/* Private structure for common edac device */
struct cpc925_dev_info {
	void __iomem *vbase;
	struct platform_device *pdev;
	char *ctl_name;
	int edac_idx;
	struct edac_device_ctl_info *edac_dev;
	void (*init)(struct cpc925_dev_info *dev_info);
	void (*exit)(struct cpc925_dev_info *dev_info);
	void (*check)(struct edac_device_ctl_info *edac_dev);
};

/* Get total memory size from Open Firmware DTB */
static void get_total_mem(struct cpc925_mc_pdata *pdata)
{
	struct device_node *np = NULL;
	const unsigned int *reg, *reg_end;
	int len, sw, aw;
	unsigned long start, size;

	np = of_find_node_by_type(NULL, "memory");
	if (!np)
		return;

	aw = of_n_addr_cells(np);
	sw = of_n_size_cells(np);
	reg = (const unsigned int *)of_get_property(np, "reg", &len);
	reg_end = reg + len/4;

	pdata->total_mem = 0;
	do {
		start = of_read_number(reg, aw);
		reg += aw;
		size = of_read_number(reg, sw);
		reg += sw;
		debugf1("%s: start 0x%lx, size 0x%lx\n", __func__,
			start, size);
		pdata->total_mem += size;
	} while (reg < reg_end);

	of_node_put(np);
	debugf0("%s: total_mem 0x%lx\n", __func__, pdata->total_mem);
}

static void cpc925_init_csrows(struct mem_ctl_info *mci)
{
	struct cpc925_mc_pdata *pdata = mci->pvt_info;
	struct csrow_info *csrow;
	int index;
	u32 mbmr, mbbar, bba;
	unsigned long row_size, last_nr_pages = 0;

	get_total_mem(pdata);

	for (index = 0; index < mci->nr_csrows; index++) {
		mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
				   0x20 * index);
		mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
				   0x20 + index);
		bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
		       ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);

		if (bba == 0)
			continue; /* not populated */

		csrow = &mci->csrows[index];

		row_size = bba * (1UL << 28);	/* 256M */
		csrow->first_page = last_nr_pages;
		csrow->nr_pages = row_size >> PAGE_SHIFT;
		csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
		last_nr_pages = csrow->last_page + 1;

		csrow->mtype = MEM_RDDR;
		csrow->edac_mode = EDAC_SECDED;

		switch (csrow->nr_channels) {
		case 1: /* Single channel */
			csrow->grain = 32; /* four-beat burst of 32 bytes */
			break;
		case 2: /* Dual channel */
		default:
			csrow->grain = 64; /* four-beat burst of 64 bytes */
			break;
		}

		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
		case 6: /* 0110, no way to differentiate X8 VS X16 */
		case 5:	/* 0101 */
		case 8: /* 1000 */
			csrow->dtype = DEV_X16;
			break;
		case 7: /* 0111 */
		case 9: /* 1001 */
			csrow->dtype = DEV_X8;
			break;
		default:
			csrow->dtype = DEV_UNKNOWN;
			break;
		}
	}
}

/* Enable memory controller ECC detection */
static void cpc925_mc_init(struct mem_ctl_info *mci)
{
	struct cpc925_mc_pdata *pdata = mci->pvt_info;
	u32 apimask;
	u32 mccr;

	/* Enable various ECC error exceptions */
	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
	if ((apimask & ECC_MASK_ENABLE) == 0) {
		apimask |= ECC_MASK_ENABLE;
		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
	}

	/* Enable ECC detection */
	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
	if ((mccr & MCCR_ECC_EN) == 0) {
		mccr |= MCCR_ECC_EN;
		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
	}
}

/* Disable memory controller ECC detection */
static void cpc925_mc_exit(struct mem_ctl_info *mci)
{
	/*
	 * WARNING:
	 * We are supposed to clear the ECC error detection bits,
	 * and it will be no problem to do so. However, once they
	 * are cleared here if we want to re-install CPC925 EDAC
	 * module later, setting them up in cpc925_mc_init() will
	 * trigger machine check exception.
	 * Also, it's ok to leave ECC error detection bits enabled,
	 * since they are reset to 1 by default or by boot loader.
	 */

	return;
}

/*
 * Revert DDR column/row/bank addresses into page frame number and
 * offset in page.
 *
 * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
 * physical address(PA) bits to column address(CA) bits mappings are:
 * CA	0   1   2   3   4   5   6   7   8   9   10
 * PA	59  58  57  56  55  54  53  52  51  50  49
 *
 * physical address(PA) bits to bank address(BA) bits mappings are:
 * BA	0   1
 * PA	43  44
 *
 * physical address(PA) bits to row address(RA) bits mappings are:
 * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
 * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
 */
static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
		unsigned long *pfn, unsigned long *offset, int *csrow)
{
	u32 bcnt, rank, col, bank, row;
	u32 c;
	unsigned long pa;
	int i;

	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
	row = mear & MEAR_ROW_MASK;

	*csrow = rank;

#ifdef CONFIG_EDAC_DEBUG
	if (mci->csrows[rank].first_page == 0) {
		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
			"non-populated csrow, broken hardware?\n");
		return;
	}
#endif

	/* Revert csrow number */
	pa = mci->csrows[rank].first_page << PAGE_SHIFT;

	/* Revert column address */
	col += bcnt;
	for (i = 0; i < 11; i++) {
		c = col & 0x1;
		col >>= 1;
		pa |= c << (14 - i);
	}

	/* Revert bank address */
	pa |= bank << 19;

	/* Revert row address, in 4 steps */
	for (i = 0; i < 3; i++) {
		c = row & 0x1;
		row >>= 1;
		pa |= c << (26 - i);
	}

	for (i = 0; i < 3; i++) {
		c = row & 0x1;
		row >>= 1;
		pa |= c << (21 + i);
	}

	for (i = 0; i < 4; i++) {
		c = row & 0x1;
		row >>= 1;
		pa |= c << (18 - i);
	}

	for (i = 0; i < 3; i++) {
		c = row & 0x1;
		row >>= 1;
		pa |= c << (29 - i);
	}

	*offset = pa & (PAGE_SIZE - 1);
	*pfn = pa >> PAGE_SHIFT;

	debugf0("%s: ECC physical address 0x%lx\n", __func__, pa);
}

static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
{
	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
		return 0;

	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
		return 1;

	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
			 syndrome);
	return 1;
}

/* Check memory controller registers for ECC errors */
static void cpc925_mc_check(struct mem_ctl_info *mci)
{
	struct cpc925_mc_pdata *pdata = mci->pvt_info;
	u32 apiexcp;
	u32 mear;
	u32 mesr;
	u16 syndrome;
	unsigned long pfn = 0, offset = 0;
	int csrow = 0, channel = 0;

	/* APIEXCP is cleared when read */
	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
		return;

	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);

	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);

	/* Revert column/row addresses into page frame number, etc */
	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);

	if (apiexcp & CECC_EXCP_DETECTED) {
		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
		channel = cpc925_mc_find_channel(mci, syndrome);
		edac_mc_handle_ce(mci, pfn, offset, syndrome,
				  csrow, channel, mci->ctl_name);
	}

	if (apiexcp & UECC_EXCP_DETECTED) {
		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
		edac_mc_handle_ue(mci, pfn, offset, csrow, mci->ctl_name);
	}

	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
		apiexcp);
	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
		mesr);
	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
		syndrome);
}

/******************** CPU err device********************************/
/* Enable CPU Errors detection */
static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
{
	u32 apimask;

	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
	if ((apimask & CPU_MASK_ENABLE) == 0) {
		apimask |= CPU_MASK_ENABLE;
		__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
	}
}

/* Disable CPU Errors detection */
static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
{
	/*
	 * WARNING:
	 * We are supposed to clear the CPU error detection bits,
	 * and it will be no problem to do so. However, once they
	 * are cleared here if we want to re-install CPC925 EDAC
	 * module later, setting them up in cpc925_cpu_init() will
	 * trigger machine check exception.
	 * Also, it's ok to leave CPU error detection bits enabled,
	 * since they are reset to 1 by default.
	 */

	return;
}

/* Check for CPU Errors */
static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
{
	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
	u32 apiexcp;
	u32 apimask;

	/* APIEXCP is cleared when read */
	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
		return;

	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
				 "Processor Interface register dump:\n");
	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);

	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
}

/******************** HT Link err device****************************/
/* Enable HyperTransport Link Error detection */
static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
{
	u32 ht_errctrl;

	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
		ht_errctrl |= HT_ERRCTRL_ENABLE;
		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
	}
}

/* Disable HyperTransport Link Error detection */
static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
{
	u32 ht_errctrl;

	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
}

/* Check for HyperTransport Link errors */
static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
{
	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);

	if (!((brgctrl & BRGCTRL_DETSERR) ||
	      (linkctrl & HT_LINKCTRL_DETECTED) ||
	      (errctrl & HT_ERRCTRL_DETECTED) ||
	      (linkerr & HT_LINKERR_DETECTED)))
		return;

	cpc925_printk(KERN_INFO, "HT Link Fault\n"
				 "HT register dump:\n");
	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
		      brgctrl);
	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
		      linkctrl);
	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
		      errctrl);
	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
		      linkerr);

	/* Clear by write 1 */
	if (brgctrl & BRGCTRL_DETSERR)
		__raw_writel(BRGCTRL_DETSERR,
				dev_info->vbase + REG_BRGCTRL_OFFSET);

	if (linkctrl & HT_LINKCTRL_DETECTED)
		__raw_writel(HT_LINKCTRL_DETECTED,
				dev_info->vbase + REG_LINKCTRL_OFFSET);

	/* Initiate Secondary Bus Reset to clear the chain failure */
	if (errctrl & ERRCTRL_CHN_FAL)
		__raw_writel(BRGCTRL_SECBUSRESET,
				dev_info->vbase + REG_BRGCTRL_OFFSET);

	if (errctrl & ERRCTRL_RSP_ERR)
		__raw_writel(ERRCTRL_RSP_ERR,
				dev_info->vbase + REG_ERRCTRL_OFFSET);

	if (linkerr & HT_LINKERR_DETECTED)
		__raw_writel(HT_LINKERR_DETECTED,
				dev_info->vbase + REG_LINKERR_OFFSET);

	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
}

static struct cpc925_dev_info cpc925_devs[] = {
	{
	.ctl_name = CPC925_CPU_ERR_DEV,
	.init = cpc925_cpu_init,
	.exit = cpc925_cpu_exit,
	.check = cpc925_cpu_check,
	},
	{
	.ctl_name = CPC925_HT_LINK_DEV,
	.init = cpc925_htlink_init,
	.exit = cpc925_htlink_exit,
	.check = cpc925_htlink_check,
	},
	{0}, /* Terminated by NULL */
};

/*
 * Add CPU Err detection and HyperTransport Link Err detection
 * as common "edac_device", they have no corresponding device
 * nodes in the Open Firmware DTB and we have to add platform
 * devices for them. Also, they will share the MMIO with that
 * of memory controller.
 */
static void cpc925_add_edac_devices(void __iomem *vbase)
{
	struct cpc925_dev_info *dev_info;

	if (!vbase) {
		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
		return;
	}

	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
		dev_info->vbase = vbase;
		dev_info->pdev = platform_device_register_simple(
					dev_info->ctl_name, 0, NULL, 0);
		if (IS_ERR(dev_info->pdev)) {
			cpc925_printk(KERN_ERR,
				"Can't register platform device for %s\n",
				dev_info->ctl_name);
			continue;
		}

		/*
		 * Don't have to allocate private structure but
		 * make use of cpc925_devs[] instead.
		 */
		dev_info->edac_idx = edac_device_alloc_index();
		dev_info->edac_dev =
			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
		if (!dev_info->edac_dev) {
			cpc925_printk(KERN_ERR, "No memory for edac device\n");
			goto err1;
		}

		dev_info->edac_dev->pvt_info = dev_info;
		dev_info->edac_dev->dev = &dev_info->pdev->dev;
		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);

		if (edac_op_state == EDAC_OPSTATE_POLL)
			dev_info->edac_dev->edac_check = dev_info->check;

		if (dev_info->init)
			dev_info->init(dev_info);

		if (edac_device_add_device(dev_info->edac_dev) > 0) {
			cpc925_printk(KERN_ERR,
				"Unable to add edac device for %s\n",
				dev_info->ctl_name);
			goto err2;
		}

		debugf0("%s: Successfully added edac device for %s\n",
			__func__, dev_info->ctl_name);

		continue;

err2:
		if (dev_info->exit)
			dev_info->exit(dev_info);
		edac_device_free_ctl_info(dev_info->edac_dev);
err1:
		platform_device_unregister(dev_info->pdev);
	}
}

/*
 * Delete the common "edac_device" for CPU Err Detection
 * and HyperTransport Link Err Detection
 */
static void cpc925_del_edac_devices(void)
{
	struct cpc925_dev_info *dev_info;

	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
		if (dev_info->edac_dev) {
			edac_device_del_device(dev_info->edac_dev->dev);
			edac_device_free_ctl_info(dev_info->edac_dev);
			platform_device_unregister(dev_info->pdev);
		}

		if (dev_info->exit)
			dev_info->exit(dev_info);

		debugf0("%s: Successfully deleted edac device for %s\n",
			__func__, dev_info->ctl_name);
	}
}

/* Convert current back-ground scrub rate into byte/sec bandwidth */
static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
{
	struct cpc925_mc_pdata *pdata = mci->pvt_info;
	int bw;
	u32 mscr;
	u8 si;

	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;

	debugf0("%s, Mem Scrub Ctrl Register 0x%x\n", __func__, mscr);

	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
	    (si == 0)) {
		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
		bw = 0;
	} else
		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;

	return bw;
}

/* Return 0 for single channel; 1 for dual channel */
static int cpc925_mc_get_channels(void __iomem *vbase)
{
	int dual = 0;
	u32 mbcr;

	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);

	/*
	 * Dual channel only when 128-bit wide physical bus
	 * and 128-bit configuration.
	 */
	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
		dual = 1;

	debugf0("%s: %s channel\n", __func__,
		(dual > 0) ? "Dual" : "Single");

	return dual;
}

static int __devinit cpc925_probe(struct platform_device *pdev)
{
	static int edac_mc_idx;
	struct mem_ctl_info *mci;
	void __iomem *vbase;
	struct cpc925_mc_pdata *pdata;
	struct resource *r;
	int res = 0, nr_channels;

	debugf0("%s: %s platform device found!\n", __func__, pdev->name);

	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
		res = -ENOMEM;
		goto out;
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		cpc925_printk(KERN_ERR, "Unable to get resource\n");
		res = -ENOENT;
		goto err1;
	}

	if (!devm_request_mem_region(&pdev->dev,
				     r->start,
				     resource_size(r),
				     pdev->name)) {
		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
		res = -EBUSY;
		goto err1;
	}

	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (!vbase) {
		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
		res = -ENOMEM;
		goto err2;
	}

	nr_channels = cpc925_mc_get_channels(vbase);
	mci = edac_mc_alloc(sizeof(struct cpc925_mc_pdata),
			CPC925_NR_CSROWS, nr_channels + 1, edac_mc_idx);
	if (!mci) {
		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
		res = -ENOMEM;
		goto err2;
	}

	pdata = mci->pvt_info;
	pdata->vbase = vbase;
	pdata->edac_idx = edac_mc_idx++;
	pdata->name = pdev->name;

	mci->dev = &pdev->dev;
	platform_set_drvdata(pdev, mci);
	mci->dev_name = dev_name(&pdev->dev);
	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
	mci->edac_cap = EDAC_FLAG_SECDED;
	mci->mod_name = CPC925_EDAC_MOD_STR;
	mci->mod_ver = CPC925_EDAC_REVISION;
	mci->ctl_name = pdev->name;

	if (edac_op_state == EDAC_OPSTATE_POLL)
		mci->edac_check = cpc925_mc_check;

	mci->ctl_page_to_phys = NULL;
	mci->scrub_mode = SCRUB_SW_SRC;
	mci->set_sdram_scrub_rate = NULL;
	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;

	cpc925_init_csrows(mci);

	/* Setup memory controller registers */
	cpc925_mc_init(mci);

	if (edac_mc_add_mc(mci) > 0) {
		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
		goto err3;
	}

	cpc925_add_edac_devices(vbase);

	/* get this far and it's successful */
	debugf0("%s: success\n", __func__);

	res = 0;
	goto out;

err3:
	cpc925_mc_exit(mci);
	edac_mc_free(mci);
err2:
	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
err1:
	devres_release_group(&pdev->dev, cpc925_probe);
out:
	return res;
}

static int cpc925_remove(struct platform_device *pdev)
{
	struct mem_ctl_info *mci = platform_get_drvdata(pdev);

	/*
	 * Delete common edac devices before edac mc, because
	 * the former share the MMIO of the latter.
	 */
	cpc925_del_edac_devices();
	cpc925_mc_exit(mci);

	edac_mc_del_mc(&pdev->dev);
	edac_mc_free(mci);

	return 0;
}

static struct platform_driver cpc925_edac_driver = {
	.probe = cpc925_probe,
	.remove = cpc925_remove,
	.driver = {
		   .name = "cpc925_edac",
	}
};

static int __init cpc925_edac_init(void)
{
	int ret = 0;

	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");

	/* Only support POLL mode so far */
	edac_op_state = EDAC_OPSTATE_POLL;

	ret = platform_driver_register(&cpc925_edac_driver);
	if (ret) {
		printk(KERN_WARNING "Failed to register %s\n",
			CPC925_EDAC_MOD_STR);
	}

	return ret;
}

static void __exit cpc925_edac_exit(void)
{
	platform_driver_unregister(&cpc925_edac_driver);
}

module_init(cpc925_edac_init);
module_exit(cpc925_edac_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");