xref: /openbmc/linux/drivers/edac/cpc925_edac.c (revision 20055477)
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 		edac_dbg(1, "start 0x%lx, size 0x%lx\n", start, size);
320 		pdata->total_mem += size;
321 	} while (reg < reg_end);
322 
323 	of_node_put(np);
324 	edac_dbg(0, "total_mem 0x%lx\n", pdata->total_mem);
325 }
326 
327 static void cpc925_init_csrows(struct mem_ctl_info *mci)
328 {
329 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
330 	struct csrow_info *csrow;
331 	struct dimm_info *dimm;
332 	enum dev_type dtype;
333 	int index, j;
334 	u32 mbmr, mbbar, bba, grain;
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 		switch (csrow->nr_channels) {
359 		case 1: /* Single channel */
360 			grain = 32; /* four-beat burst of 32 bytes */
361 			break;
362 		case 2: /* Dual channel */
363 		default:
364 			grain = 64; /* four-beat burst of 64 bytes */
365 			break;
366 		}
367 		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
368 		case 6: /* 0110, no way to differentiate X8 VS X16 */
369 		case 5:	/* 0101 */
370 		case 8: /* 1000 */
371 			dtype = DEV_X16;
372 			break;
373 		case 7: /* 0111 */
374 		case 9: /* 1001 */
375 			dtype = DEV_X8;
376 			break;
377 		default:
378 			dtype = DEV_UNKNOWN;
379 		break;
380 		}
381 		for (j = 0; j < csrow->nr_channels; j++) {
382 			dimm = csrow->channels[j]->dimm;
383 			dimm->nr_pages = nr_pages / csrow->nr_channels;
384 			dimm->mtype = MEM_RDDR;
385 			dimm->edac_mode = EDAC_SECDED;
386 			dimm->grain = grain;
387 			dimm->dtype = dtype;
388 		}
389 	}
390 }
391 
392 /* Enable memory controller ECC detection */
393 static void cpc925_mc_init(struct mem_ctl_info *mci)
394 {
395 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
396 	u32 apimask;
397 	u32 mccr;
398 
399 	/* Enable various ECC error exceptions */
400 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
401 	if ((apimask & ECC_MASK_ENABLE) == 0) {
402 		apimask |= ECC_MASK_ENABLE;
403 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
404 	}
405 
406 	/* Enable ECC detection */
407 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
408 	if ((mccr & MCCR_ECC_EN) == 0) {
409 		mccr |= MCCR_ECC_EN;
410 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
411 	}
412 }
413 
414 /* Disable memory controller ECC detection */
415 static void cpc925_mc_exit(struct mem_ctl_info *mci)
416 {
417 	/*
418 	 * WARNING:
419 	 * We are supposed to clear the ECC error detection bits,
420 	 * and it will be no problem to do so. However, once they
421 	 * are cleared here if we want to re-install CPC925 EDAC
422 	 * module later, setting them up in cpc925_mc_init() will
423 	 * trigger machine check exception.
424 	 * Also, it's ok to leave ECC error detection bits enabled,
425 	 * since they are reset to 1 by default or by boot loader.
426 	 */
427 
428 	return;
429 }
430 
431 /*
432  * Revert DDR column/row/bank addresses into page frame number and
433  * offset in page.
434  *
435  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
436  * physical address(PA) bits to column address(CA) bits mappings are:
437  * CA	0   1   2   3   4   5   6   7   8   9   10
438  * PA	59  58  57  56  55  54  53  52  51  50  49
439  *
440  * physical address(PA) bits to bank address(BA) bits mappings are:
441  * BA	0   1
442  * PA	43  44
443  *
444  * physical address(PA) bits to row address(RA) bits mappings are:
445  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
446  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
447  */
448 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
449 		unsigned long *pfn, unsigned long *offset, int *csrow)
450 {
451 	u32 bcnt, rank, col, bank, row;
452 	u32 c;
453 	unsigned long pa;
454 	int i;
455 
456 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
457 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
458 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
459 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
460 	row = mear & MEAR_ROW_MASK;
461 
462 	*csrow = rank;
463 
464 #ifdef CONFIG_EDAC_DEBUG
465 	if (mci->csrows[rank]->first_page == 0) {
466 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
467 			"non-populated csrow, broken hardware?\n");
468 		return;
469 	}
470 #endif
471 
472 	/* Revert csrow number */
473 	pa = mci->csrows[rank]->first_page << PAGE_SHIFT;
474 
475 	/* Revert column address */
476 	col += bcnt;
477 	for (i = 0; i < 11; i++) {
478 		c = col & 0x1;
479 		col >>= 1;
480 		pa |= c << (14 - i);
481 	}
482 
483 	/* Revert bank address */
484 	pa |= bank << 19;
485 
486 	/* Revert row address, in 4 steps */
487 	for (i = 0; i < 3; i++) {
488 		c = row & 0x1;
489 		row >>= 1;
490 		pa |= c << (26 - i);
491 	}
492 
493 	for (i = 0; i < 3; i++) {
494 		c = row & 0x1;
495 		row >>= 1;
496 		pa |= c << (21 + i);
497 	}
498 
499 	for (i = 0; i < 4; i++) {
500 		c = row & 0x1;
501 		row >>= 1;
502 		pa |= c << (18 - i);
503 	}
504 
505 	for (i = 0; i < 3; i++) {
506 		c = row & 0x1;
507 		row >>= 1;
508 		pa |= c << (29 - i);
509 	}
510 
511 	*offset = pa & (PAGE_SIZE - 1);
512 	*pfn = pa >> PAGE_SHIFT;
513 
514 	edac_dbg(0, "ECC physical address 0x%lx\n", pa);
515 }
516 
517 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
518 {
519 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
520 		return 0;
521 
522 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
523 		return 1;
524 
525 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
526 			 syndrome);
527 	return 1;
528 }
529 
530 /* Check memory controller registers for ECC errors */
531 static void cpc925_mc_check(struct mem_ctl_info *mci)
532 {
533 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
534 	u32 apiexcp;
535 	u32 mear;
536 	u32 mesr;
537 	u16 syndrome;
538 	unsigned long pfn = 0, offset = 0;
539 	int csrow = 0, channel = 0;
540 
541 	/* APIEXCP is cleared when read */
542 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
543 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
544 		return;
545 
546 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
547 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
548 
549 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
550 
551 	/* Revert column/row addresses into page frame number, etc */
552 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
553 
554 	if (apiexcp & CECC_EXCP_DETECTED) {
555 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
556 		channel = cpc925_mc_find_channel(mci, syndrome);
557 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
558 				     pfn, offset, syndrome,
559 				     csrow, channel, -1,
560 				     mci->ctl_name, "");
561 	}
562 
563 	if (apiexcp & UECC_EXCP_DETECTED) {
564 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
565 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
566 				     pfn, offset, 0,
567 				     csrow, -1, -1,
568 				     mci->ctl_name, "");
569 	}
570 
571 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
572 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
573 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
574 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
575 		apiexcp);
576 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
577 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
578 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
579 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
580 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
581 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
582 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
583 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
584 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
585 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
586 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
587 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
588 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
589 		mesr);
590 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
591 		syndrome);
592 }
593 
594 /******************** CPU err device********************************/
595 static u32 cpc925_cpu_mask_disabled(void)
596 {
597 	struct device_node *cpus;
598 	struct device_node *cpunode = NULL;
599 	static u32 mask = 0;
600 
601 	/* use cached value if available */
602 	if (mask != 0)
603 		return mask;
604 
605 	mask = APIMASK_ADI0 | APIMASK_ADI1;
606 
607 	cpus = of_find_node_by_path("/cpus");
608 	if (cpus == NULL) {
609 		cpc925_printk(KERN_DEBUG, "No /cpus node !\n");
610 		return 0;
611 	}
612 
613 	while ((cpunode = of_get_next_child(cpus, cpunode)) != NULL) {
614 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
615 
616 		if (strcmp(cpunode->type, "cpu")) {
617 			cpc925_printk(KERN_ERR, "Not a cpu node in /cpus: %s\n", cpunode->name);
618 			continue;
619 		}
620 
621 		if (reg == NULL || *reg > 2) {
622 			cpc925_printk(KERN_ERR, "Bad reg value at %s\n", cpunode->full_name);
623 			continue;
624 		}
625 
626 		mask &= ~APIMASK_ADI(*reg);
627 	}
628 
629 	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
630 		/* We assume that each CPU sits on it's own PI and that
631 		 * for present CPUs the reg property equals to the PI
632 		 * interface id */
633 		cpc925_printk(KERN_WARNING,
634 				"Assuming PI id is equal to CPU MPIC id!\n");
635 	}
636 
637 	of_node_put(cpunode);
638 	of_node_put(cpus);
639 
640 	return mask;
641 }
642 
643 /* Enable CPU Errors detection */
644 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
645 {
646 	u32 apimask;
647 	u32 cpumask;
648 
649 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
650 
651 	cpumask = cpc925_cpu_mask_disabled();
652 	if (apimask & cpumask) {
653 		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
654 				"but enabled in APIMASK, disabling\n");
655 		apimask &= ~cpumask;
656 	}
657 
658 	if ((apimask & CPU_MASK_ENABLE) == 0)
659 		apimask |= CPU_MASK_ENABLE;
660 
661 	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
662 }
663 
664 /* Disable CPU Errors detection */
665 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
666 {
667 	/*
668 	 * WARNING:
669 	 * We are supposed to clear the CPU error detection bits,
670 	 * and it will be no problem to do so. However, once they
671 	 * are cleared here if we want to re-install CPC925 EDAC
672 	 * module later, setting them up in cpc925_cpu_init() will
673 	 * trigger machine check exception.
674 	 * Also, it's ok to leave CPU error detection bits enabled,
675 	 * since they are reset to 1 by default.
676 	 */
677 
678 	return;
679 }
680 
681 /* Check for CPU Errors */
682 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
683 {
684 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
685 	u32 apiexcp;
686 	u32 apimask;
687 
688 	/* APIEXCP is cleared when read */
689 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
690 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
691 		return;
692 
693 	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
694 		return;
695 
696 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
697 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
698 				 "Processor Interface register dump:\n");
699 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
700 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
701 
702 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
703 }
704 
705 /******************** HT Link err device****************************/
706 /* Enable HyperTransport Link Error detection */
707 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
708 {
709 	u32 ht_errctrl;
710 
711 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
712 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
713 		ht_errctrl |= HT_ERRCTRL_ENABLE;
714 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
715 	}
716 }
717 
718 /* Disable HyperTransport Link Error detection */
719 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
720 {
721 	u32 ht_errctrl;
722 
723 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
724 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
725 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
726 }
727 
728 /* Check for HyperTransport Link errors */
729 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
730 {
731 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
732 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
733 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
734 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
735 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
736 
737 	if (!((brgctrl & BRGCTRL_DETSERR) ||
738 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
739 	      (errctrl & HT_ERRCTRL_DETECTED) ||
740 	      (linkerr & HT_LINKERR_DETECTED)))
741 		return;
742 
743 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
744 				 "HT register dump:\n");
745 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
746 		      brgctrl);
747 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
748 		      linkctrl);
749 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
750 		      errctrl);
751 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
752 		      linkerr);
753 
754 	/* Clear by write 1 */
755 	if (brgctrl & BRGCTRL_DETSERR)
756 		__raw_writel(BRGCTRL_DETSERR,
757 				dev_info->vbase + REG_BRGCTRL_OFFSET);
758 
759 	if (linkctrl & HT_LINKCTRL_DETECTED)
760 		__raw_writel(HT_LINKCTRL_DETECTED,
761 				dev_info->vbase + REG_LINKCTRL_OFFSET);
762 
763 	/* Initiate Secondary Bus Reset to clear the chain failure */
764 	if (errctrl & ERRCTRL_CHN_FAL)
765 		__raw_writel(BRGCTRL_SECBUSRESET,
766 				dev_info->vbase + REG_BRGCTRL_OFFSET);
767 
768 	if (errctrl & ERRCTRL_RSP_ERR)
769 		__raw_writel(ERRCTRL_RSP_ERR,
770 				dev_info->vbase + REG_ERRCTRL_OFFSET);
771 
772 	if (linkerr & HT_LINKERR_DETECTED)
773 		__raw_writel(HT_LINKERR_DETECTED,
774 				dev_info->vbase + REG_LINKERR_OFFSET);
775 
776 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
777 }
778 
779 static struct cpc925_dev_info cpc925_devs[] = {
780 	{
781 	.ctl_name = CPC925_CPU_ERR_DEV,
782 	.init = cpc925_cpu_init,
783 	.exit = cpc925_cpu_exit,
784 	.check = cpc925_cpu_check,
785 	},
786 	{
787 	.ctl_name = CPC925_HT_LINK_DEV,
788 	.init = cpc925_htlink_init,
789 	.exit = cpc925_htlink_exit,
790 	.check = cpc925_htlink_check,
791 	},
792 	{ }
793 };
794 
795 /*
796  * Add CPU Err detection and HyperTransport Link Err detection
797  * as common "edac_device", they have no corresponding device
798  * nodes in the Open Firmware DTB and we have to add platform
799  * devices for them. Also, they will share the MMIO with that
800  * of memory controller.
801  */
802 static void cpc925_add_edac_devices(void __iomem *vbase)
803 {
804 	struct cpc925_dev_info *dev_info;
805 
806 	if (!vbase) {
807 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
808 		return;
809 	}
810 
811 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
812 		dev_info->vbase = vbase;
813 		dev_info->pdev = platform_device_register_simple(
814 					dev_info->ctl_name, 0, NULL, 0);
815 		if (IS_ERR(dev_info->pdev)) {
816 			cpc925_printk(KERN_ERR,
817 				"Can't register platform device for %s\n",
818 				dev_info->ctl_name);
819 			continue;
820 		}
821 
822 		/*
823 		 * Don't have to allocate private structure but
824 		 * make use of cpc925_devs[] instead.
825 		 */
826 		dev_info->edac_idx = edac_device_alloc_index();
827 		dev_info->edac_dev =
828 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
829 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
830 		if (!dev_info->edac_dev) {
831 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
832 			goto err1;
833 		}
834 
835 		dev_info->edac_dev->pvt_info = dev_info;
836 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
837 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
838 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
839 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
840 
841 		if (edac_op_state == EDAC_OPSTATE_POLL)
842 			dev_info->edac_dev->edac_check = dev_info->check;
843 
844 		if (dev_info->init)
845 			dev_info->init(dev_info);
846 
847 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
848 			cpc925_printk(KERN_ERR,
849 				"Unable to add edac device for %s\n",
850 				dev_info->ctl_name);
851 			goto err2;
852 		}
853 
854 		edac_dbg(0, "Successfully added edac device for %s\n",
855 			 dev_info->ctl_name);
856 
857 		continue;
858 
859 err2:
860 		if (dev_info->exit)
861 			dev_info->exit(dev_info);
862 		edac_device_free_ctl_info(dev_info->edac_dev);
863 err1:
864 		platform_device_unregister(dev_info->pdev);
865 	}
866 }
867 
868 /*
869  * Delete the common "edac_device" for CPU Err Detection
870  * and HyperTransport Link Err Detection
871  */
872 static void cpc925_del_edac_devices(void)
873 {
874 	struct cpc925_dev_info *dev_info;
875 
876 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
877 		if (dev_info->edac_dev) {
878 			edac_device_del_device(dev_info->edac_dev->dev);
879 			edac_device_free_ctl_info(dev_info->edac_dev);
880 			platform_device_unregister(dev_info->pdev);
881 		}
882 
883 		if (dev_info->exit)
884 			dev_info->exit(dev_info);
885 
886 		edac_dbg(0, "Successfully deleted edac device for %s\n",
887 			 dev_info->ctl_name);
888 	}
889 }
890 
891 /* Convert current back-ground scrub rate into byte/sec bandwidth */
892 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
893 {
894 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
895 	int bw;
896 	u32 mscr;
897 	u8 si;
898 
899 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
900 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
901 
902 	edac_dbg(0, "Mem Scrub Ctrl Register 0x%x\n", mscr);
903 
904 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
905 	    (si == 0)) {
906 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
907 		bw = 0;
908 	} else
909 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
910 
911 	return bw;
912 }
913 
914 /* Return 0 for single channel; 1 for dual channel */
915 static int cpc925_mc_get_channels(void __iomem *vbase)
916 {
917 	int dual = 0;
918 	u32 mbcr;
919 
920 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
921 
922 	/*
923 	 * Dual channel only when 128-bit wide physical bus
924 	 * and 128-bit configuration.
925 	 */
926 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
927 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
928 		dual = 1;
929 
930 	edac_dbg(0, "%s channel\n", (dual > 0) ? "Dual" : "Single");
931 
932 	return dual;
933 }
934 
935 static int cpc925_probe(struct platform_device *pdev)
936 {
937 	static int edac_mc_idx;
938 	struct mem_ctl_info *mci;
939 	struct edac_mc_layer layers[2];
940 	void __iomem *vbase;
941 	struct cpc925_mc_pdata *pdata;
942 	struct resource *r;
943 	int res = 0, nr_channels;
944 
945 	edac_dbg(0, "%s platform device found!\n", pdev->name);
946 
947 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
948 		res = -ENOMEM;
949 		goto out;
950 	}
951 
952 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
953 	if (!r) {
954 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
955 		res = -ENOENT;
956 		goto err1;
957 	}
958 
959 	if (!devm_request_mem_region(&pdev->dev,
960 				     r->start,
961 				     resource_size(r),
962 				     pdev->name)) {
963 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
964 		res = -EBUSY;
965 		goto err1;
966 	}
967 
968 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
969 	if (!vbase) {
970 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
971 		res = -ENOMEM;
972 		goto err2;
973 	}
974 
975 	nr_channels = cpc925_mc_get_channels(vbase) + 1;
976 
977 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
978 	layers[0].size = CPC925_NR_CSROWS;
979 	layers[0].is_virt_csrow = true;
980 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
981 	layers[1].size = nr_channels;
982 	layers[1].is_virt_csrow = false;
983 	mci = edac_mc_alloc(edac_mc_idx, ARRAY_SIZE(layers), layers,
984 			    sizeof(struct cpc925_mc_pdata));
985 	if (!mci) {
986 		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
987 		res = -ENOMEM;
988 		goto err2;
989 	}
990 
991 	pdata = mci->pvt_info;
992 	pdata->vbase = vbase;
993 	pdata->edac_idx = edac_mc_idx++;
994 	pdata->name = pdev->name;
995 
996 	mci->pdev = &pdev->dev;
997 	platform_set_drvdata(pdev, mci);
998 	mci->dev_name = dev_name(&pdev->dev);
999 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
1000 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
1001 	mci->edac_cap = EDAC_FLAG_SECDED;
1002 	mci->mod_name = CPC925_EDAC_MOD_STR;
1003 	mci->mod_ver = CPC925_EDAC_REVISION;
1004 	mci->ctl_name = pdev->name;
1005 
1006 	if (edac_op_state == EDAC_OPSTATE_POLL)
1007 		mci->edac_check = cpc925_mc_check;
1008 
1009 	mci->ctl_page_to_phys = NULL;
1010 	mci->scrub_mode = SCRUB_SW_SRC;
1011 	mci->set_sdram_scrub_rate = NULL;
1012 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
1013 
1014 	cpc925_init_csrows(mci);
1015 
1016 	/* Setup memory controller registers */
1017 	cpc925_mc_init(mci);
1018 
1019 	if (edac_mc_add_mc(mci) > 0) {
1020 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
1021 		goto err3;
1022 	}
1023 
1024 	cpc925_add_edac_devices(vbase);
1025 
1026 	/* get this far and it's successful */
1027 	edac_dbg(0, "success\n");
1028 
1029 	res = 0;
1030 	goto out;
1031 
1032 err3:
1033 	cpc925_mc_exit(mci);
1034 	edac_mc_free(mci);
1035 err2:
1036 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
1037 err1:
1038 	devres_release_group(&pdev->dev, cpc925_probe);
1039 out:
1040 	return res;
1041 }
1042 
1043 static int cpc925_remove(struct platform_device *pdev)
1044 {
1045 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
1046 
1047 	/*
1048 	 * Delete common edac devices before edac mc, because
1049 	 * the former share the MMIO of the latter.
1050 	 */
1051 	cpc925_del_edac_devices();
1052 	cpc925_mc_exit(mci);
1053 
1054 	edac_mc_del_mc(&pdev->dev);
1055 	edac_mc_free(mci);
1056 
1057 	return 0;
1058 }
1059 
1060 static struct platform_driver cpc925_edac_driver = {
1061 	.probe = cpc925_probe,
1062 	.remove = cpc925_remove,
1063 	.driver = {
1064 		   .name = "cpc925_edac",
1065 	}
1066 };
1067 
1068 static int __init cpc925_edac_init(void)
1069 {
1070 	int ret = 0;
1071 
1072 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
1073 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
1074 
1075 	/* Only support POLL mode so far */
1076 	edac_op_state = EDAC_OPSTATE_POLL;
1077 
1078 	ret = platform_driver_register(&cpc925_edac_driver);
1079 	if (ret) {
1080 		printk(KERN_WARNING "Failed to register %s\n",
1081 			CPC925_EDAC_MOD_STR);
1082 	}
1083 
1084 	return ret;
1085 }
1086 
1087 static void __exit cpc925_edac_exit(void)
1088 {
1089 	platform_driver_unregister(&cpc925_edac_driver);
1090 }
1091 
1092 module_init(cpc925_edac_init);
1093 module_exit(cpc925_edac_exit);
1094 
1095 MODULE_LICENSE("GPL");
1096 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1097 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1098