xref: /linux/drivers/edac/cpc925_edac.c (revision b9ccfda293ee6fca9a89a1584f0900e0627b975e)
1 /*
2  * cpc925_edac.c, EDAC driver for IBM CPC925 Bridge and Memory Controller.
3  *
4  * Copyright (c) 2008 Wind River Systems, Inc.
5  *
6  * Authors:	Cao Qingtao <qingtao.cao@windriver.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
15  * See the GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/io.h>
25 #include <linux/edac.h>
26 #include <linux/of.h>
27 #include <linux/platform_device.h>
28 #include <linux/gfp.h>
29 
30 #include "edac_core.h"
31 #include "edac_module.h"
32 
33 #define CPC925_EDAC_REVISION	" Ver: 1.0.0"
34 #define CPC925_EDAC_MOD_STR	"cpc925_edac"
35 
36 #define cpc925_printk(level, fmt, arg...) \
37 	edac_printk(level, "CPC925", fmt, ##arg)
38 
39 #define cpc925_mc_printk(mci, level, fmt, arg...) \
40 	edac_mc_chipset_printk(mci, level, "CPC925", fmt, ##arg)
41 
42 /*
43  * CPC925 registers are of 32 bits with bit0 defined at the
44  * most significant bit and bit31 at that of least significant.
45  */
46 #define CPC925_BITS_PER_REG	32
47 #define CPC925_BIT(nr)		(1UL << (CPC925_BITS_PER_REG - 1 - nr))
48 
49 /*
50  * EDAC device names for the error detections of
51  * CPU Interface and Hypertransport Link.
52  */
53 #define CPC925_CPU_ERR_DEV	"cpu"
54 #define CPC925_HT_LINK_DEV	"htlink"
55 
56 /* Suppose DDR Refresh cycle is 15.6 microsecond */
57 #define CPC925_REF_FREQ		0xFA69
58 #define CPC925_SCRUB_BLOCK_SIZE 64	/* bytes */
59 #define CPC925_NR_CSROWS	8
60 
61 /*
62  * All registers and bits definitions are taken from
63  * "CPC925 Bridge and Memory Controller User Manual, SA14-2761-02".
64  */
65 
66 /*
67  * CPU and Memory Controller Registers
68  */
69 /************************************************************
70  *	Processor Interface Exception Mask Register (APIMASK)
71  ************************************************************/
72 #define REG_APIMASK_OFFSET	0x30070
73 enum apimask_bits {
74 	APIMASK_DART	= CPC925_BIT(0), /* DART Exception */
75 	APIMASK_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
76 	APIMASK_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
77 	APIMASK_STAT	= CPC925_BIT(3), /* Status Exception */
78 	APIMASK_DERR	= CPC925_BIT(4), /* Data Error Exception */
79 	APIMASK_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
80 	APIMASK_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
81 					 /* BIT(7) Reserved */
82 	APIMASK_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
83 	APIMASK_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
84 	APIMASK_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
85 	APIMASK_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
86 
87 	CPU_MASK_ENABLE = (APIMASK_DART | APIMASK_ADI0 | APIMASK_ADI1 |
88 			   APIMASK_STAT | APIMASK_DERR | APIMASK_ADRS0 |
89 			   APIMASK_ADRS1),
90 	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
91 			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
92 };
93 #define APIMASK_ADI(n)		CPC925_BIT(((n)+1))
94 
95 /************************************************************
96  *	Processor Interface Exception Register (APIEXCP)
97  ************************************************************/
98 #define REG_APIEXCP_OFFSET	0x30060
99 enum apiexcp_bits {
100 	APIEXCP_DART	= CPC925_BIT(0), /* DART Exception */
101 	APIEXCP_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
102 	APIEXCP_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
103 	APIEXCP_STAT	= CPC925_BIT(3), /* Status Exception */
104 	APIEXCP_DERR	= CPC925_BIT(4), /* Data Error Exception */
105 	APIEXCP_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
106 	APIEXCP_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
107 					 /* BIT(7) Reserved */
108 	APIEXCP_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
109 	APIEXCP_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
110 	APIEXCP_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
111 	APIEXCP_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
112 
113 	CPU_EXCP_DETECTED = (APIEXCP_DART | APIEXCP_ADI0 | APIEXCP_ADI1 |
114 			     APIEXCP_STAT | APIEXCP_DERR | APIEXCP_ADRS0 |
115 			     APIEXCP_ADRS1),
116 	UECC_EXCP_DETECTED = (APIEXCP_ECC_UE_H | APIEXCP_ECC_UE_L),
117 	CECC_EXCP_DETECTED = (APIEXCP_ECC_CE_H | APIEXCP_ECC_CE_L),
118 	ECC_EXCP_DETECTED = (UECC_EXCP_DETECTED | CECC_EXCP_DETECTED),
119 };
120 
121 /************************************************************
122  *	Memory Bus Configuration Register (MBCR)
123 ************************************************************/
124 #define REG_MBCR_OFFSET		0x2190
125 #define MBCR_64BITCFG_SHIFT	23
126 #define MBCR_64BITCFG_MASK	(1UL << MBCR_64BITCFG_SHIFT)
127 #define MBCR_64BITBUS_SHIFT	22
128 #define MBCR_64BITBUS_MASK	(1UL << MBCR_64BITBUS_SHIFT)
129 
130 /************************************************************
131  *	Memory Bank Mode Register (MBMR)
132 ************************************************************/
133 #define REG_MBMR_OFFSET		0x21C0
134 #define MBMR_MODE_MAX_VALUE	0xF
135 #define MBMR_MODE_SHIFT		25
136 #define MBMR_MODE_MASK		(MBMR_MODE_MAX_VALUE << MBMR_MODE_SHIFT)
137 #define MBMR_BBA_SHIFT		24
138 #define MBMR_BBA_MASK		(1UL << MBMR_BBA_SHIFT)
139 
140 /************************************************************
141  *	Memory Bank Boundary Address Register (MBBAR)
142  ************************************************************/
143 #define REG_MBBAR_OFFSET	0x21D0
144 #define MBBAR_BBA_MAX_VALUE	0xFF
145 #define MBBAR_BBA_SHIFT		24
146 #define MBBAR_BBA_MASK		(MBBAR_BBA_MAX_VALUE << MBBAR_BBA_SHIFT)
147 
148 /************************************************************
149  *	Memory Scrub Control Register (MSCR)
150  ************************************************************/
151 #define REG_MSCR_OFFSET		0x2400
152 #define MSCR_SCRUB_MOD_MASK	0xC0000000 /* scrub_mod - bit0:1*/
153 #define MSCR_BACKGR_SCRUB	0x40000000 /* 01 */
154 #define MSCR_SI_SHIFT		16 	/* si - bit8:15*/
155 #define MSCR_SI_MAX_VALUE	0xFF
156 #define MSCR_SI_MASK		(MSCR_SI_MAX_VALUE << MSCR_SI_SHIFT)
157 
158 /************************************************************
159  *	Memory Scrub Range Start Register (MSRSR)
160  ************************************************************/
161 #define REG_MSRSR_OFFSET	0x2410
162 
163 /************************************************************
164  *	Memory Scrub Range End Register (MSRER)
165  ************************************************************/
166 #define REG_MSRER_OFFSET	0x2420
167 
168 /************************************************************
169  *	Memory Scrub Pattern Register (MSPR)
170  ************************************************************/
171 #define REG_MSPR_OFFSET		0x2430
172 
173 /************************************************************
174  *	Memory Check Control Register (MCCR)
175  ************************************************************/
176 #define REG_MCCR_OFFSET		0x2440
177 enum mccr_bits {
178 	MCCR_ECC_EN	= CPC925_BIT(0), /* ECC high and low check */
179 };
180 
181 /************************************************************
182  *	Memory Check Range End Register (MCRER)
183  ************************************************************/
184 #define REG_MCRER_OFFSET	0x2450
185 
186 /************************************************************
187  *	Memory Error Address Register (MEAR)
188  ************************************************************/
189 #define REG_MEAR_OFFSET		0x2460
190 #define MEAR_BCNT_MAX_VALUE	0x3
191 #define MEAR_BCNT_SHIFT		30
192 #define MEAR_BCNT_MASK		(MEAR_BCNT_MAX_VALUE << MEAR_BCNT_SHIFT)
193 #define MEAR_RANK_MAX_VALUE	0x7
194 #define MEAR_RANK_SHIFT		27
195 #define MEAR_RANK_MASK		(MEAR_RANK_MAX_VALUE << MEAR_RANK_SHIFT)
196 #define MEAR_COL_MAX_VALUE	0x7FF
197 #define MEAR_COL_SHIFT		16
198 #define MEAR_COL_MASK		(MEAR_COL_MAX_VALUE << MEAR_COL_SHIFT)
199 #define MEAR_BANK_MAX_VALUE	0x3
200 #define MEAR_BANK_SHIFT		14
201 #define MEAR_BANK_MASK		(MEAR_BANK_MAX_VALUE << MEAR_BANK_SHIFT)
202 #define MEAR_ROW_MASK		0x00003FFF
203 
204 /************************************************************
205  *	Memory Error Syndrome Register (MESR)
206  ************************************************************/
207 #define REG_MESR_OFFSET		0x2470
208 #define MESR_ECC_SYN_H_MASK	0xFF00
209 #define MESR_ECC_SYN_L_MASK	0x00FF
210 
211 /************************************************************
212  *	Memory Mode Control Register (MMCR)
213  ************************************************************/
214 #define REG_MMCR_OFFSET		0x2500
215 enum mmcr_bits {
216 	MMCR_REG_DIMM_MODE = CPC925_BIT(3),
217 };
218 
219 /*
220  * HyperTransport Link Registers
221  */
222 /************************************************************
223  *  Error Handling/Enumeration Scratch Pad Register (ERRCTRL)
224  ************************************************************/
225 #define REG_ERRCTRL_OFFSET	0x70140
226 enum errctrl_bits {			 /* nonfatal interrupts for */
227 	ERRCTRL_SERR_NF	= CPC925_BIT(0), /* system error */
228 	ERRCTRL_CRC_NF	= CPC925_BIT(1), /* CRC error */
229 	ERRCTRL_RSP_NF	= CPC925_BIT(2), /* Response error */
230 	ERRCTRL_EOC_NF	= CPC925_BIT(3), /* End-Of-Chain error */
231 	ERRCTRL_OVF_NF	= CPC925_BIT(4), /* Overflow error */
232 	ERRCTRL_PROT_NF	= CPC925_BIT(5), /* Protocol error */
233 
234 	ERRCTRL_RSP_ERR	= CPC925_BIT(6), /* Response error received */
235 	ERRCTRL_CHN_FAL = CPC925_BIT(7), /* Sync flooding detected */
236 
237 	HT_ERRCTRL_ENABLE = (ERRCTRL_SERR_NF | ERRCTRL_CRC_NF |
238 			     ERRCTRL_RSP_NF | ERRCTRL_EOC_NF |
239 			     ERRCTRL_OVF_NF | ERRCTRL_PROT_NF),
240 	HT_ERRCTRL_DETECTED = (ERRCTRL_RSP_ERR | ERRCTRL_CHN_FAL),
241 };
242 
243 /************************************************************
244  *  Link Configuration and Link Control Register (LINKCTRL)
245  ************************************************************/
246 #define REG_LINKCTRL_OFFSET	0x70110
247 enum linkctrl_bits {
248 	LINKCTRL_CRC_ERR	= (CPC925_BIT(22) | CPC925_BIT(23)),
249 	LINKCTRL_LINK_FAIL	= CPC925_BIT(27),
250 
251 	HT_LINKCTRL_DETECTED	= (LINKCTRL_CRC_ERR | LINKCTRL_LINK_FAIL),
252 };
253 
254 /************************************************************
255  *  Link FreqCap/Error/Freq/Revision ID Register (LINKERR)
256  ************************************************************/
257 #define REG_LINKERR_OFFSET	0x70120
258 enum linkerr_bits {
259 	LINKERR_EOC_ERR		= CPC925_BIT(17), /* End-Of-Chain error */
260 	LINKERR_OVF_ERR		= CPC925_BIT(18), /* Receive Buffer Overflow */
261 	LINKERR_PROT_ERR	= CPC925_BIT(19), /* Protocol error */
262 
263 	HT_LINKERR_DETECTED	= (LINKERR_EOC_ERR | LINKERR_OVF_ERR |
264 				   LINKERR_PROT_ERR),
265 };
266 
267 /************************************************************
268  *	Bridge Control Register (BRGCTRL)
269  ************************************************************/
270 #define REG_BRGCTRL_OFFSET	0x70300
271 enum brgctrl_bits {
272 	BRGCTRL_DETSERR = CPC925_BIT(0), /* SERR on Secondary Bus */
273 	BRGCTRL_SECBUSRESET = CPC925_BIT(9), /* Secondary Bus Reset */
274 };
275 
276 /* Private structure for edac memory controller */
277 struct cpc925_mc_pdata {
278 	void __iomem *vbase;
279 	unsigned long total_mem;
280 	const char *name;
281 	int edac_idx;
282 };
283 
284 /* Private structure for common edac device */
285 struct cpc925_dev_info {
286 	void __iomem *vbase;
287 	struct platform_device *pdev;
288 	char *ctl_name;
289 	int edac_idx;
290 	struct edac_device_ctl_info *edac_dev;
291 	void (*init)(struct cpc925_dev_info *dev_info);
292 	void (*exit)(struct cpc925_dev_info *dev_info);
293 	void (*check)(struct edac_device_ctl_info *edac_dev);
294 };
295 
296 /* Get total memory size from Open Firmware DTB */
297 static void get_total_mem(struct cpc925_mc_pdata *pdata)
298 {
299 	struct device_node *np = NULL;
300 	const unsigned int *reg, *reg_end;
301 	int len, sw, aw;
302 	unsigned long start, size;
303 
304 	np = of_find_node_by_type(NULL, "memory");
305 	if (!np)
306 		return;
307 
308 	aw = of_n_addr_cells(np);
309 	sw = of_n_size_cells(np);
310 	reg = (const unsigned int *)of_get_property(np, "reg", &len);
311 	reg_end = reg + len/4;
312 
313 	pdata->total_mem = 0;
314 	do {
315 		start = of_read_number(reg, aw);
316 		reg += aw;
317 		size = of_read_number(reg, sw);
318 		reg += sw;
319 		debugf1("%s: start 0x%lx, size 0x%lx\n", __func__,
320 			start, size);
321 		pdata->total_mem += size;
322 	} while (reg < reg_end);
323 
324 	of_node_put(np);
325 	debugf0("%s: total_mem 0x%lx\n", __func__, pdata->total_mem);
326 }
327 
328 static void cpc925_init_csrows(struct mem_ctl_info *mci)
329 {
330 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
331 	struct csrow_info *csrow;
332 	struct dimm_info *dimm;
333 	int index, j;
334 	u32 mbmr, mbbar, bba;
335 	unsigned long row_size, nr_pages, last_nr_pages = 0;
336 
337 	get_total_mem(pdata);
338 
339 	for (index = 0; index < mci->nr_csrows; index++) {
340 		mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
341 				   0x20 * index);
342 		mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
343 				   0x20 + index);
344 		bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
345 		       ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);
346 
347 		if (bba == 0)
348 			continue; /* not populated */
349 
350 		csrow = &mci->csrows[index];
351 
352 		row_size = bba * (1UL << 28);	/* 256M */
353 		csrow->first_page = last_nr_pages;
354 		nr_pages = row_size >> PAGE_SHIFT;
355 		csrow->last_page = csrow->first_page + nr_pages - 1;
356 		last_nr_pages = csrow->last_page + 1;
357 
358 		for (j = 0; j < csrow->nr_channels; j++) {
359 			dimm = csrow->channels[j].dimm;
360 
361 			dimm->nr_pages = nr_pages / csrow->nr_channels;
362 			dimm->mtype = MEM_RDDR;
363 			dimm->edac_mode = EDAC_SECDED;
364 
365 			switch (csrow->nr_channels) {
366 			case 1: /* Single channel */
367 				dimm->grain = 32; /* four-beat burst of 32 bytes */
368 				break;
369 			case 2: /* Dual channel */
370 			default:
371 				dimm->grain = 64; /* four-beat burst of 64 bytes */
372 				break;
373 			}
374 
375 			switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
376 			case 6: /* 0110, no way to differentiate X8 VS X16 */
377 			case 5:	/* 0101 */
378 			case 8: /* 1000 */
379 				dimm->dtype = DEV_X16;
380 				break;
381 			case 7: /* 0111 */
382 			case 9: /* 1001 */
383 				dimm->dtype = DEV_X8;
384 				break;
385 			default:
386 				dimm->dtype = DEV_UNKNOWN;
387 				break;
388 			}
389 		}
390 	}
391 }
392 
393 /* Enable memory controller ECC detection */
394 static void cpc925_mc_init(struct mem_ctl_info *mci)
395 {
396 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
397 	u32 apimask;
398 	u32 mccr;
399 
400 	/* Enable various ECC error exceptions */
401 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
402 	if ((apimask & ECC_MASK_ENABLE) == 0) {
403 		apimask |= ECC_MASK_ENABLE;
404 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
405 	}
406 
407 	/* Enable ECC detection */
408 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
409 	if ((mccr & MCCR_ECC_EN) == 0) {
410 		mccr |= MCCR_ECC_EN;
411 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
412 	}
413 }
414 
415 /* Disable memory controller ECC detection */
416 static void cpc925_mc_exit(struct mem_ctl_info *mci)
417 {
418 	/*
419 	 * WARNING:
420 	 * We are supposed to clear the ECC error detection bits,
421 	 * and it will be no problem to do so. However, once they
422 	 * are cleared here if we want to re-install CPC925 EDAC
423 	 * module later, setting them up in cpc925_mc_init() will
424 	 * trigger machine check exception.
425 	 * Also, it's ok to leave ECC error detection bits enabled,
426 	 * since they are reset to 1 by default or by boot loader.
427 	 */
428 
429 	return;
430 }
431 
432 /*
433  * Revert DDR column/row/bank addresses into page frame number and
434  * offset in page.
435  *
436  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
437  * physical address(PA) bits to column address(CA) bits mappings are:
438  * CA	0   1   2   3   4   5   6   7   8   9   10
439  * PA	59  58  57  56  55  54  53  52  51  50  49
440  *
441  * physical address(PA) bits to bank address(BA) bits mappings are:
442  * BA	0   1
443  * PA	43  44
444  *
445  * physical address(PA) bits to row address(RA) bits mappings are:
446  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
447  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
448  */
449 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
450 		unsigned long *pfn, unsigned long *offset, int *csrow)
451 {
452 	u32 bcnt, rank, col, bank, row;
453 	u32 c;
454 	unsigned long pa;
455 	int i;
456 
457 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
458 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
459 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
460 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
461 	row = mear & MEAR_ROW_MASK;
462 
463 	*csrow = rank;
464 
465 #ifdef CONFIG_EDAC_DEBUG
466 	if (mci->csrows[rank].first_page == 0) {
467 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
468 			"non-populated csrow, broken hardware?\n");
469 		return;
470 	}
471 #endif
472 
473 	/* Revert csrow number */
474 	pa = mci->csrows[rank].first_page << PAGE_SHIFT;
475 
476 	/* Revert column address */
477 	col += bcnt;
478 	for (i = 0; i < 11; i++) {
479 		c = col & 0x1;
480 		col >>= 1;
481 		pa |= c << (14 - i);
482 	}
483 
484 	/* Revert bank address */
485 	pa |= bank << 19;
486 
487 	/* Revert row address, in 4 steps */
488 	for (i = 0; i < 3; i++) {
489 		c = row & 0x1;
490 		row >>= 1;
491 		pa |= c << (26 - i);
492 	}
493 
494 	for (i = 0; i < 3; i++) {
495 		c = row & 0x1;
496 		row >>= 1;
497 		pa |= c << (21 + i);
498 	}
499 
500 	for (i = 0; i < 4; i++) {
501 		c = row & 0x1;
502 		row >>= 1;
503 		pa |= c << (18 - i);
504 	}
505 
506 	for (i = 0; i < 3; i++) {
507 		c = row & 0x1;
508 		row >>= 1;
509 		pa |= c << (29 - i);
510 	}
511 
512 	*offset = pa & (PAGE_SIZE - 1);
513 	*pfn = pa >> PAGE_SHIFT;
514 
515 	debugf0("%s: ECC physical address 0x%lx\n", __func__, pa);
516 }
517 
518 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
519 {
520 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
521 		return 0;
522 
523 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
524 		return 1;
525 
526 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
527 			 syndrome);
528 	return 1;
529 }
530 
531 /* Check memory controller registers for ECC errors */
532 static void cpc925_mc_check(struct mem_ctl_info *mci)
533 {
534 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
535 	u32 apiexcp;
536 	u32 mear;
537 	u32 mesr;
538 	u16 syndrome;
539 	unsigned long pfn = 0, offset = 0;
540 	int csrow = 0, channel = 0;
541 
542 	/* APIEXCP is cleared when read */
543 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
544 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
545 		return;
546 
547 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
548 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
549 
550 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
551 
552 	/* Revert column/row addresses into page frame number, etc */
553 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
554 
555 	if (apiexcp & CECC_EXCP_DETECTED) {
556 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
557 		channel = cpc925_mc_find_channel(mci, syndrome);
558 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci,
559 				     pfn, offset, syndrome,
560 				     csrow, channel, -1,
561 				     mci->ctl_name, "", NULL);
562 	}
563 
564 	if (apiexcp & UECC_EXCP_DETECTED) {
565 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
566 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci,
567 				     pfn, offset, 0,
568 				     csrow, -1, -1,
569 				     mci->ctl_name, "", NULL);
570 	}
571 
572 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
573 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
574 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
575 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
576 		apiexcp);
577 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
578 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
579 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
580 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
581 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
582 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
583 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
584 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
585 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
586 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
587 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
588 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
589 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
590 		mesr);
591 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
592 		syndrome);
593 }
594 
595 /******************** CPU err device********************************/
596 static u32 cpc925_cpu_mask_disabled(void)
597 {
598 	struct device_node *cpus;
599 	struct device_node *cpunode = NULL;
600 	static u32 mask = 0;
601 
602 	/* use cached value if available */
603 	if (mask != 0)
604 		return mask;
605 
606 	mask = APIMASK_ADI0 | APIMASK_ADI1;
607 
608 	cpus = of_find_node_by_path("/cpus");
609 	if (cpus == NULL) {
610 		cpc925_printk(KERN_DEBUG, "No /cpus node !\n");
611 		return 0;
612 	}
613 
614 	while ((cpunode = of_get_next_child(cpus, cpunode)) != NULL) {
615 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
616 
617 		if (strcmp(cpunode->type, "cpu")) {
618 			cpc925_printk(KERN_ERR, "Not a cpu node in /cpus: %s\n", cpunode->name);
619 			continue;
620 		}
621 
622 		if (reg == NULL || *reg > 2) {
623 			cpc925_printk(KERN_ERR, "Bad reg value at %s\n", cpunode->full_name);
624 			continue;
625 		}
626 
627 		mask &= ~APIMASK_ADI(*reg);
628 	}
629 
630 	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
631 		/* We assume that each CPU sits on it's own PI and that
632 		 * for present CPUs the reg property equals to the PI
633 		 * interface id */
634 		cpc925_printk(KERN_WARNING,
635 				"Assuming PI id is equal to CPU MPIC id!\n");
636 	}
637 
638 	of_node_put(cpunode);
639 	of_node_put(cpus);
640 
641 	return mask;
642 }
643 
644 /* Enable CPU Errors detection */
645 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
646 {
647 	u32 apimask;
648 	u32 cpumask;
649 
650 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
651 
652 	cpumask = cpc925_cpu_mask_disabled();
653 	if (apimask & cpumask) {
654 		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
655 				"but enabled in APIMASK, disabling\n");
656 		apimask &= ~cpumask;
657 	}
658 
659 	if ((apimask & CPU_MASK_ENABLE) == 0)
660 		apimask |= CPU_MASK_ENABLE;
661 
662 	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
663 }
664 
665 /* Disable CPU Errors detection */
666 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
667 {
668 	/*
669 	 * WARNING:
670 	 * We are supposed to clear the CPU error detection bits,
671 	 * and it will be no problem to do so. However, once they
672 	 * are cleared here if we want to re-install CPC925 EDAC
673 	 * module later, setting them up in cpc925_cpu_init() will
674 	 * trigger machine check exception.
675 	 * Also, it's ok to leave CPU error detection bits enabled,
676 	 * since they are reset to 1 by default.
677 	 */
678 
679 	return;
680 }
681 
682 /* Check for CPU Errors */
683 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
684 {
685 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
686 	u32 apiexcp;
687 	u32 apimask;
688 
689 	/* APIEXCP is cleared when read */
690 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
691 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
692 		return;
693 
694 	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
695 		return;
696 
697 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
698 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
699 				 "Processor Interface register dump:\n");
700 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
701 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
702 
703 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
704 }
705 
706 /******************** HT Link err device****************************/
707 /* Enable HyperTransport Link Error detection */
708 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
709 {
710 	u32 ht_errctrl;
711 
712 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
713 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
714 		ht_errctrl |= HT_ERRCTRL_ENABLE;
715 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
716 	}
717 }
718 
719 /* Disable HyperTransport Link Error detection */
720 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
721 {
722 	u32 ht_errctrl;
723 
724 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
725 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
726 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
727 }
728 
729 /* Check for HyperTransport Link errors */
730 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
731 {
732 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
733 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
734 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
735 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
736 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
737 
738 	if (!((brgctrl & BRGCTRL_DETSERR) ||
739 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
740 	      (errctrl & HT_ERRCTRL_DETECTED) ||
741 	      (linkerr & HT_LINKERR_DETECTED)))
742 		return;
743 
744 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
745 				 "HT register dump:\n");
746 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
747 		      brgctrl);
748 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
749 		      linkctrl);
750 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
751 		      errctrl);
752 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
753 		      linkerr);
754 
755 	/* Clear by write 1 */
756 	if (brgctrl & BRGCTRL_DETSERR)
757 		__raw_writel(BRGCTRL_DETSERR,
758 				dev_info->vbase + REG_BRGCTRL_OFFSET);
759 
760 	if (linkctrl & HT_LINKCTRL_DETECTED)
761 		__raw_writel(HT_LINKCTRL_DETECTED,
762 				dev_info->vbase + REG_LINKCTRL_OFFSET);
763 
764 	/* Initiate Secondary Bus Reset to clear the chain failure */
765 	if (errctrl & ERRCTRL_CHN_FAL)
766 		__raw_writel(BRGCTRL_SECBUSRESET,
767 				dev_info->vbase + REG_BRGCTRL_OFFSET);
768 
769 	if (errctrl & ERRCTRL_RSP_ERR)
770 		__raw_writel(ERRCTRL_RSP_ERR,
771 				dev_info->vbase + REG_ERRCTRL_OFFSET);
772 
773 	if (linkerr & HT_LINKERR_DETECTED)
774 		__raw_writel(HT_LINKERR_DETECTED,
775 				dev_info->vbase + REG_LINKERR_OFFSET);
776 
777 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
778 }
779 
780 static struct cpc925_dev_info cpc925_devs[] = {
781 	{
782 	.ctl_name = CPC925_CPU_ERR_DEV,
783 	.init = cpc925_cpu_init,
784 	.exit = cpc925_cpu_exit,
785 	.check = cpc925_cpu_check,
786 	},
787 	{
788 	.ctl_name = CPC925_HT_LINK_DEV,
789 	.init = cpc925_htlink_init,
790 	.exit = cpc925_htlink_exit,
791 	.check = cpc925_htlink_check,
792 	},
793 	{0}, /* Terminated by NULL */
794 };
795 
796 /*
797  * Add CPU Err detection and HyperTransport Link Err detection
798  * as common "edac_device", they have no corresponding device
799  * nodes in the Open Firmware DTB and we have to add platform
800  * devices for them. Also, they will share the MMIO with that
801  * of memory controller.
802  */
803 static void cpc925_add_edac_devices(void __iomem *vbase)
804 {
805 	struct cpc925_dev_info *dev_info;
806 
807 	if (!vbase) {
808 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
809 		return;
810 	}
811 
812 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
813 		dev_info->vbase = vbase;
814 		dev_info->pdev = platform_device_register_simple(
815 					dev_info->ctl_name, 0, NULL, 0);
816 		if (IS_ERR(dev_info->pdev)) {
817 			cpc925_printk(KERN_ERR,
818 				"Can't register platform device for %s\n",
819 				dev_info->ctl_name);
820 			continue;
821 		}
822 
823 		/*
824 		 * Don't have to allocate private structure but
825 		 * make use of cpc925_devs[] instead.
826 		 */
827 		dev_info->edac_idx = edac_device_alloc_index();
828 		dev_info->edac_dev =
829 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
830 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
831 		if (!dev_info->edac_dev) {
832 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
833 			goto err1;
834 		}
835 
836 		dev_info->edac_dev->pvt_info = dev_info;
837 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
838 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
839 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
840 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
841 
842 		if (edac_op_state == EDAC_OPSTATE_POLL)
843 			dev_info->edac_dev->edac_check = dev_info->check;
844 
845 		if (dev_info->init)
846 			dev_info->init(dev_info);
847 
848 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
849 			cpc925_printk(KERN_ERR,
850 				"Unable to add edac device for %s\n",
851 				dev_info->ctl_name);
852 			goto err2;
853 		}
854 
855 		debugf0("%s: Successfully added edac device for %s\n",
856 			__func__, dev_info->ctl_name);
857 
858 		continue;
859 
860 err2:
861 		if (dev_info->exit)
862 			dev_info->exit(dev_info);
863 		edac_device_free_ctl_info(dev_info->edac_dev);
864 err1:
865 		platform_device_unregister(dev_info->pdev);
866 	}
867 }
868 
869 /*
870  * Delete the common "edac_device" for CPU Err Detection
871  * and HyperTransport Link Err Detection
872  */
873 static void cpc925_del_edac_devices(void)
874 {
875 	struct cpc925_dev_info *dev_info;
876 
877 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
878 		if (dev_info->edac_dev) {
879 			edac_device_del_device(dev_info->edac_dev->dev);
880 			edac_device_free_ctl_info(dev_info->edac_dev);
881 			platform_device_unregister(dev_info->pdev);
882 		}
883 
884 		if (dev_info->exit)
885 			dev_info->exit(dev_info);
886 
887 		debugf0("%s: Successfully deleted edac device for %s\n",
888 			__func__, dev_info->ctl_name);
889 	}
890 }
891 
892 /* Convert current back-ground scrub rate into byte/sec bandwidth */
893 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
894 {
895 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
896 	int bw;
897 	u32 mscr;
898 	u8 si;
899 
900 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
901 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
902 
903 	debugf0("%s, Mem Scrub Ctrl Register 0x%x\n", __func__, mscr);
904 
905 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
906 	    (si == 0)) {
907 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
908 		bw = 0;
909 	} else
910 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
911 
912 	return bw;
913 }
914 
915 /* Return 0 for single channel; 1 for dual channel */
916 static int cpc925_mc_get_channels(void __iomem *vbase)
917 {
918 	int dual = 0;
919 	u32 mbcr;
920 
921 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
922 
923 	/*
924 	 * Dual channel only when 128-bit wide physical bus
925 	 * and 128-bit configuration.
926 	 */
927 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
928 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
929 		dual = 1;
930 
931 	debugf0("%s: %s channel\n", __func__,
932 		(dual > 0) ? "Dual" : "Single");
933 
934 	return dual;
935 }
936 
937 static int __devinit cpc925_probe(struct platform_device *pdev)
938 {
939 	static int edac_mc_idx;
940 	struct mem_ctl_info *mci;
941 	struct edac_mc_layer layers[2];
942 	void __iomem *vbase;
943 	struct cpc925_mc_pdata *pdata;
944 	struct resource *r;
945 	int res = 0, nr_channels;
946 
947 	debugf0("%s: %s platform device found!\n", __func__, pdev->name);
948 
949 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
950 		res = -ENOMEM;
951 		goto out;
952 	}
953 
954 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
955 	if (!r) {
956 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
957 		res = -ENOENT;
958 		goto err1;
959 	}
960 
961 	if (!devm_request_mem_region(&pdev->dev,
962 				     r->start,
963 				     resource_size(r),
964 				     pdev->name)) {
965 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
966 		res = -EBUSY;
967 		goto err1;
968 	}
969 
970 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
971 	if (!vbase) {
972 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
973 		res = -ENOMEM;
974 		goto err2;
975 	}
976 
977 	nr_channels = cpc925_mc_get_channels(vbase) + 1;
978 
979 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
980 	layers[0].size = CPC925_NR_CSROWS;
981 	layers[0].is_virt_csrow = true;
982 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
983 	layers[1].size = nr_channels;
984 	layers[1].is_virt_csrow = false;
985 	mci = edac_mc_alloc(edac_mc_idx, ARRAY_SIZE(layers), layers,
986 			    sizeof(struct cpc925_mc_pdata));
987 	if (!mci) {
988 		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
989 		res = -ENOMEM;
990 		goto err2;
991 	}
992 
993 	pdata = mci->pvt_info;
994 	pdata->vbase = vbase;
995 	pdata->edac_idx = edac_mc_idx++;
996 	pdata->name = pdev->name;
997 
998 	mci->dev = &pdev->dev;
999 	platform_set_drvdata(pdev, mci);
1000 	mci->dev_name = dev_name(&pdev->dev);
1001 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
1002 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
1003 	mci->edac_cap = EDAC_FLAG_SECDED;
1004 	mci->mod_name = CPC925_EDAC_MOD_STR;
1005 	mci->mod_ver = CPC925_EDAC_REVISION;
1006 	mci->ctl_name = pdev->name;
1007 
1008 	if (edac_op_state == EDAC_OPSTATE_POLL)
1009 		mci->edac_check = cpc925_mc_check;
1010 
1011 	mci->ctl_page_to_phys = NULL;
1012 	mci->scrub_mode = SCRUB_SW_SRC;
1013 	mci->set_sdram_scrub_rate = NULL;
1014 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
1015 
1016 	cpc925_init_csrows(mci);
1017 
1018 	/* Setup memory controller registers */
1019 	cpc925_mc_init(mci);
1020 
1021 	if (edac_mc_add_mc(mci) > 0) {
1022 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
1023 		goto err3;
1024 	}
1025 
1026 	cpc925_add_edac_devices(vbase);
1027 
1028 	/* get this far and it's successful */
1029 	debugf0("%s: success\n", __func__);
1030 
1031 	res = 0;
1032 	goto out;
1033 
1034 err3:
1035 	cpc925_mc_exit(mci);
1036 	edac_mc_free(mci);
1037 err2:
1038 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
1039 err1:
1040 	devres_release_group(&pdev->dev, cpc925_probe);
1041 out:
1042 	return res;
1043 }
1044 
1045 static int cpc925_remove(struct platform_device *pdev)
1046 {
1047 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
1048 
1049 	/*
1050 	 * Delete common edac devices before edac mc, because
1051 	 * the former share the MMIO of the latter.
1052 	 */
1053 	cpc925_del_edac_devices();
1054 	cpc925_mc_exit(mci);
1055 
1056 	edac_mc_del_mc(&pdev->dev);
1057 	edac_mc_free(mci);
1058 
1059 	return 0;
1060 }
1061 
1062 static struct platform_driver cpc925_edac_driver = {
1063 	.probe = cpc925_probe,
1064 	.remove = cpc925_remove,
1065 	.driver = {
1066 		   .name = "cpc925_edac",
1067 	}
1068 };
1069 
1070 static int __init cpc925_edac_init(void)
1071 {
1072 	int ret = 0;
1073 
1074 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
1075 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
1076 
1077 	/* Only support POLL mode so far */
1078 	edac_op_state = EDAC_OPSTATE_POLL;
1079 
1080 	ret = platform_driver_register(&cpc925_edac_driver);
1081 	if (ret) {
1082 		printk(KERN_WARNING "Failed to register %s\n",
1083 			CPC925_EDAC_MOD_STR);
1084 	}
1085 
1086 	return ret;
1087 }
1088 
1089 static void __exit cpc925_edac_exit(void)
1090 {
1091 	platform_driver_unregister(&cpc925_edac_driver);
1092 }
1093 
1094 module_init(cpc925_edac_init);
1095 module_exit(cpc925_edac_exit);
1096 
1097 MODULE_LICENSE("GPL");
1098 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1099 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1100