xref: /openbmc/linux/drivers/edac/cpc925_edac.c (revision be709d48)
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_module.h"
31 
32 #define CPC925_EDAC_REVISION	" Ver: 1.0.0"
33 #define CPC925_EDAC_MOD_STR	"cpc925_edac"
34 
35 #define cpc925_printk(level, fmt, arg...) \
36 	edac_printk(level, "CPC925", fmt, ##arg)
37 
38 #define cpc925_mc_printk(mci, level, fmt, arg...) \
39 	edac_mc_chipset_printk(mci, level, "CPC925", fmt, ##arg)
40 
41 /*
42  * CPC925 registers are of 32 bits with bit0 defined at the
43  * most significant bit and bit31 at that of least significant.
44  */
45 #define CPC925_BITS_PER_REG	32
46 #define CPC925_BIT(nr)		(1UL << (CPC925_BITS_PER_REG - 1 - nr))
47 
48 /*
49  * EDAC device names for the error detections of
50  * CPU Interface and Hypertransport Link.
51  */
52 #define CPC925_CPU_ERR_DEV	"cpu"
53 #define CPC925_HT_LINK_DEV	"htlink"
54 
55 /* Suppose DDR Refresh cycle is 15.6 microsecond */
56 #define CPC925_REF_FREQ		0xFA69
57 #define CPC925_SCRUB_BLOCK_SIZE 64	/* bytes */
58 #define CPC925_NR_CSROWS	8
59 
60 /*
61  * All registers and bits definitions are taken from
62  * "CPC925 Bridge and Memory Controller User Manual, SA14-2761-02".
63  */
64 
65 /*
66  * CPU and Memory Controller Registers
67  */
68 /************************************************************
69  *	Processor Interface Exception Mask Register (APIMASK)
70  ************************************************************/
71 #define REG_APIMASK_OFFSET	0x30070
72 enum apimask_bits {
73 	APIMASK_DART	= CPC925_BIT(0), /* DART Exception */
74 	APIMASK_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
75 	APIMASK_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
76 	APIMASK_STAT	= CPC925_BIT(3), /* Status Exception */
77 	APIMASK_DERR	= CPC925_BIT(4), /* Data Error Exception */
78 	APIMASK_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
79 	APIMASK_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
80 					 /* BIT(7) Reserved */
81 	APIMASK_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
82 	APIMASK_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
83 	APIMASK_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
84 	APIMASK_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
85 
86 	CPU_MASK_ENABLE = (APIMASK_DART | APIMASK_ADI0 | APIMASK_ADI1 |
87 			   APIMASK_STAT | APIMASK_DERR | APIMASK_ADRS0 |
88 			   APIMASK_ADRS1),
89 	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
90 			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
91 };
92 #define APIMASK_ADI(n)		CPC925_BIT(((n)+1))
93 
94 /************************************************************
95  *	Processor Interface Exception Register (APIEXCP)
96  ************************************************************/
97 #define REG_APIEXCP_OFFSET	0x30060
98 enum apiexcp_bits {
99 	APIEXCP_DART	= CPC925_BIT(0), /* DART Exception */
100 	APIEXCP_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
101 	APIEXCP_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
102 	APIEXCP_STAT	= CPC925_BIT(3), /* Status Exception */
103 	APIEXCP_DERR	= CPC925_BIT(4), /* Data Error Exception */
104 	APIEXCP_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
105 	APIEXCP_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
106 					 /* BIT(7) Reserved */
107 	APIEXCP_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
108 	APIEXCP_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
109 	APIEXCP_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
110 	APIEXCP_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
111 
112 	CPU_EXCP_DETECTED = (APIEXCP_DART | APIEXCP_ADI0 | APIEXCP_ADI1 |
113 			     APIEXCP_STAT | APIEXCP_DERR | APIEXCP_ADRS0 |
114 			     APIEXCP_ADRS1),
115 	UECC_EXCP_DETECTED = (APIEXCP_ECC_UE_H | APIEXCP_ECC_UE_L),
116 	CECC_EXCP_DETECTED = (APIEXCP_ECC_CE_H | APIEXCP_ECC_CE_L),
117 	ECC_EXCP_DETECTED = (UECC_EXCP_DETECTED | CECC_EXCP_DETECTED),
118 };
119 
120 /************************************************************
121  *	Memory Bus Configuration Register (MBCR)
122 ************************************************************/
123 #define REG_MBCR_OFFSET		0x2190
124 #define MBCR_64BITCFG_SHIFT	23
125 #define MBCR_64BITCFG_MASK	(1UL << MBCR_64BITCFG_SHIFT)
126 #define MBCR_64BITBUS_SHIFT	22
127 #define MBCR_64BITBUS_MASK	(1UL << MBCR_64BITBUS_SHIFT)
128 
129 /************************************************************
130  *	Memory Bank Mode Register (MBMR)
131 ************************************************************/
132 #define REG_MBMR_OFFSET		0x21C0
133 #define MBMR_MODE_MAX_VALUE	0xF
134 #define MBMR_MODE_SHIFT		25
135 #define MBMR_MODE_MASK		(MBMR_MODE_MAX_VALUE << MBMR_MODE_SHIFT)
136 #define MBMR_BBA_SHIFT		24
137 #define MBMR_BBA_MASK		(1UL << MBMR_BBA_SHIFT)
138 
139 /************************************************************
140  *	Memory Bank Boundary Address Register (MBBAR)
141  ************************************************************/
142 #define REG_MBBAR_OFFSET	0x21D0
143 #define MBBAR_BBA_MAX_VALUE	0xFF
144 #define MBBAR_BBA_SHIFT		24
145 #define MBBAR_BBA_MASK		(MBBAR_BBA_MAX_VALUE << MBBAR_BBA_SHIFT)
146 
147 /************************************************************
148  *	Memory Scrub Control Register (MSCR)
149  ************************************************************/
150 #define REG_MSCR_OFFSET		0x2400
151 #define MSCR_SCRUB_MOD_MASK	0xC0000000 /* scrub_mod - bit0:1*/
152 #define MSCR_BACKGR_SCRUB	0x40000000 /* 01 */
153 #define MSCR_SI_SHIFT		16 	/* si - bit8:15*/
154 #define MSCR_SI_MAX_VALUE	0xFF
155 #define MSCR_SI_MASK		(MSCR_SI_MAX_VALUE << MSCR_SI_SHIFT)
156 
157 /************************************************************
158  *	Memory Scrub Range Start Register (MSRSR)
159  ************************************************************/
160 #define REG_MSRSR_OFFSET	0x2410
161 
162 /************************************************************
163  *	Memory Scrub Range End Register (MSRER)
164  ************************************************************/
165 #define REG_MSRER_OFFSET	0x2420
166 
167 /************************************************************
168  *	Memory Scrub Pattern Register (MSPR)
169  ************************************************************/
170 #define REG_MSPR_OFFSET		0x2430
171 
172 /************************************************************
173  *	Memory Check Control Register (MCCR)
174  ************************************************************/
175 #define REG_MCCR_OFFSET		0x2440
176 enum mccr_bits {
177 	MCCR_ECC_EN	= CPC925_BIT(0), /* ECC high and low check */
178 };
179 
180 /************************************************************
181  *	Memory Check Range End Register (MCRER)
182  ************************************************************/
183 #define REG_MCRER_OFFSET	0x2450
184 
185 /************************************************************
186  *	Memory Error Address Register (MEAR)
187  ************************************************************/
188 #define REG_MEAR_OFFSET		0x2460
189 #define MEAR_BCNT_MAX_VALUE	0x3
190 #define MEAR_BCNT_SHIFT		30
191 #define MEAR_BCNT_MASK		(MEAR_BCNT_MAX_VALUE << MEAR_BCNT_SHIFT)
192 #define MEAR_RANK_MAX_VALUE	0x7
193 #define MEAR_RANK_SHIFT		27
194 #define MEAR_RANK_MASK		(MEAR_RANK_MAX_VALUE << MEAR_RANK_SHIFT)
195 #define MEAR_COL_MAX_VALUE	0x7FF
196 #define MEAR_COL_SHIFT		16
197 #define MEAR_COL_MASK		(MEAR_COL_MAX_VALUE << MEAR_COL_SHIFT)
198 #define MEAR_BANK_MAX_VALUE	0x3
199 #define MEAR_BANK_SHIFT		14
200 #define MEAR_BANK_MASK		(MEAR_BANK_MAX_VALUE << MEAR_BANK_SHIFT)
201 #define MEAR_ROW_MASK		0x00003FFF
202 
203 /************************************************************
204  *	Memory Error Syndrome Register (MESR)
205  ************************************************************/
206 #define REG_MESR_OFFSET		0x2470
207 #define MESR_ECC_SYN_H_MASK	0xFF00
208 #define MESR_ECC_SYN_L_MASK	0x00FF
209 
210 /************************************************************
211  *	Memory Mode Control Register (MMCR)
212  ************************************************************/
213 #define REG_MMCR_OFFSET		0x2500
214 enum mmcr_bits {
215 	MMCR_REG_DIMM_MODE = CPC925_BIT(3),
216 };
217 
218 /*
219  * HyperTransport Link Registers
220  */
221 /************************************************************
222  *  Error Handling/Enumeration Scratch Pad Register (ERRCTRL)
223  ************************************************************/
224 #define REG_ERRCTRL_OFFSET	0x70140
225 enum errctrl_bits {			 /* nonfatal interrupts for */
226 	ERRCTRL_SERR_NF	= CPC925_BIT(0), /* system error */
227 	ERRCTRL_CRC_NF	= CPC925_BIT(1), /* CRC error */
228 	ERRCTRL_RSP_NF	= CPC925_BIT(2), /* Response error */
229 	ERRCTRL_EOC_NF	= CPC925_BIT(3), /* End-Of-Chain error */
230 	ERRCTRL_OVF_NF	= CPC925_BIT(4), /* Overflow error */
231 	ERRCTRL_PROT_NF	= CPC925_BIT(5), /* Protocol error */
232 
233 	ERRCTRL_RSP_ERR	= CPC925_BIT(6), /* Response error received */
234 	ERRCTRL_CHN_FAL = CPC925_BIT(7), /* Sync flooding detected */
235 
236 	HT_ERRCTRL_ENABLE = (ERRCTRL_SERR_NF | ERRCTRL_CRC_NF |
237 			     ERRCTRL_RSP_NF | ERRCTRL_EOC_NF |
238 			     ERRCTRL_OVF_NF | ERRCTRL_PROT_NF),
239 	HT_ERRCTRL_DETECTED = (ERRCTRL_RSP_ERR | ERRCTRL_CHN_FAL),
240 };
241 
242 /************************************************************
243  *  Link Configuration and Link Control Register (LINKCTRL)
244  ************************************************************/
245 #define REG_LINKCTRL_OFFSET	0x70110
246 enum linkctrl_bits {
247 	LINKCTRL_CRC_ERR	= (CPC925_BIT(22) | CPC925_BIT(23)),
248 	LINKCTRL_LINK_FAIL	= CPC925_BIT(27),
249 
250 	HT_LINKCTRL_DETECTED	= (LINKCTRL_CRC_ERR | LINKCTRL_LINK_FAIL),
251 };
252 
253 /************************************************************
254  *  Link FreqCap/Error/Freq/Revision ID Register (LINKERR)
255  ************************************************************/
256 #define REG_LINKERR_OFFSET	0x70120
257 enum linkerr_bits {
258 	LINKERR_EOC_ERR		= CPC925_BIT(17), /* End-Of-Chain error */
259 	LINKERR_OVF_ERR		= CPC925_BIT(18), /* Receive Buffer Overflow */
260 	LINKERR_PROT_ERR	= CPC925_BIT(19), /* Protocol error */
261 
262 	HT_LINKERR_DETECTED	= (LINKERR_EOC_ERR | LINKERR_OVF_ERR |
263 				   LINKERR_PROT_ERR),
264 };
265 
266 /************************************************************
267  *	Bridge Control Register (BRGCTRL)
268  ************************************************************/
269 #define REG_BRGCTRL_OFFSET	0x70300
270 enum brgctrl_bits {
271 	BRGCTRL_DETSERR = CPC925_BIT(0), /* SERR on Secondary Bus */
272 	BRGCTRL_SECBUSRESET = CPC925_BIT(9), /* Secondary Bus Reset */
273 };
274 
275 /* Private structure for edac memory controller */
276 struct cpc925_mc_pdata {
277 	void __iomem *vbase;
278 	unsigned long total_mem;
279 	const char *name;
280 	int edac_idx;
281 };
282 
283 /* Private structure for common edac device */
284 struct cpc925_dev_info {
285 	void __iomem *vbase;
286 	struct platform_device *pdev;
287 	char *ctl_name;
288 	int edac_idx;
289 	struct edac_device_ctl_info *edac_dev;
290 	void (*init)(struct cpc925_dev_info *dev_info);
291 	void (*exit)(struct cpc925_dev_info *dev_info);
292 	void (*check)(struct edac_device_ctl_info *edac_dev);
293 };
294 
295 /* Get total memory size from Open Firmware DTB */
296 static void get_total_mem(struct cpc925_mc_pdata *pdata)
297 {
298 	struct device_node *np = NULL;
299 	const unsigned int *reg, *reg_end;
300 	int len, sw, aw;
301 	unsigned long start, size;
302 
303 	np = of_find_node_by_type(NULL, "memory");
304 	if (!np)
305 		return;
306 
307 	aw = of_n_addr_cells(np);
308 	sw = of_n_size_cells(np);
309 	reg = (const unsigned int *)of_get_property(np, "reg", &len);
310 	reg_end = reg + len/4;
311 
312 	pdata->total_mem = 0;
313 	do {
314 		start = of_read_number(reg, aw);
315 		reg += aw;
316 		size = of_read_number(reg, sw);
317 		reg += sw;
318 		edac_dbg(1, "start 0x%lx, size 0x%lx\n", start, size);
319 		pdata->total_mem += size;
320 	} while (reg < reg_end);
321 
322 	of_node_put(np);
323 	edac_dbg(0, "total_mem 0x%lx\n", pdata->total_mem);
324 }
325 
326 static void cpc925_init_csrows(struct mem_ctl_info *mci)
327 {
328 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
329 	struct csrow_info *csrow;
330 	struct dimm_info *dimm;
331 	enum dev_type dtype;
332 	int index, j;
333 	u32 mbmr, mbbar, bba, grain;
334 	unsigned long row_size, nr_pages, last_nr_pages = 0;
335 
336 	get_total_mem(pdata);
337 
338 	for (index = 0; index < mci->nr_csrows; index++) {
339 		mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
340 				   0x20 * index);
341 		mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
342 				   0x20 + index);
343 		bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
344 		       ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);
345 
346 		if (bba == 0)
347 			continue; /* not populated */
348 
349 		csrow = mci->csrows[index];
350 
351 		row_size = bba * (1UL << 28);	/* 256M */
352 		csrow->first_page = last_nr_pages;
353 		nr_pages = row_size >> PAGE_SHIFT;
354 		csrow->last_page = csrow->first_page + nr_pages - 1;
355 		last_nr_pages = csrow->last_page + 1;
356 
357 		switch (csrow->nr_channels) {
358 		case 1: /* Single channel */
359 			grain = 32; /* four-beat burst of 32 bytes */
360 			break;
361 		case 2: /* Dual channel */
362 		default:
363 			grain = 64; /* four-beat burst of 64 bytes */
364 			break;
365 		}
366 		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
367 		case 6: /* 0110, no way to differentiate X8 VS X16 */
368 		case 5:	/* 0101 */
369 		case 8: /* 1000 */
370 			dtype = DEV_X16;
371 			break;
372 		case 7: /* 0111 */
373 		case 9: /* 1001 */
374 			dtype = DEV_X8;
375 			break;
376 		default:
377 			dtype = DEV_UNKNOWN;
378 		break;
379 		}
380 		for (j = 0; j < csrow->nr_channels; j++) {
381 			dimm = csrow->channels[j]->dimm;
382 			dimm->nr_pages = nr_pages / csrow->nr_channels;
383 			dimm->mtype = MEM_RDDR;
384 			dimm->edac_mode = EDAC_SECDED;
385 			dimm->grain = grain;
386 			dimm->dtype = dtype;
387 		}
388 	}
389 }
390 
391 /* Enable memory controller ECC detection */
392 static void cpc925_mc_init(struct mem_ctl_info *mci)
393 {
394 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
395 	u32 apimask;
396 	u32 mccr;
397 
398 	/* Enable various ECC error exceptions */
399 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
400 	if ((apimask & ECC_MASK_ENABLE) == 0) {
401 		apimask |= ECC_MASK_ENABLE;
402 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
403 	}
404 
405 	/* Enable ECC detection */
406 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
407 	if ((mccr & MCCR_ECC_EN) == 0) {
408 		mccr |= MCCR_ECC_EN;
409 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
410 	}
411 }
412 
413 /* Disable memory controller ECC detection */
414 static void cpc925_mc_exit(struct mem_ctl_info *mci)
415 {
416 	/*
417 	 * WARNING:
418 	 * We are supposed to clear the ECC error detection bits,
419 	 * and it will be no problem to do so. However, once they
420 	 * are cleared here if we want to re-install CPC925 EDAC
421 	 * module later, setting them up in cpc925_mc_init() will
422 	 * trigger machine check exception.
423 	 * Also, it's ok to leave ECC error detection bits enabled,
424 	 * since they are reset to 1 by default or by boot loader.
425 	 */
426 
427 	return;
428 }
429 
430 /*
431  * Revert DDR column/row/bank addresses into page frame number and
432  * offset in page.
433  *
434  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
435  * physical address(PA) bits to column address(CA) bits mappings are:
436  * CA	0   1   2   3   4   5   6   7   8   9   10
437  * PA	59  58  57  56  55  54  53  52  51  50  49
438  *
439  * physical address(PA) bits to bank address(BA) bits mappings are:
440  * BA	0   1
441  * PA	43  44
442  *
443  * physical address(PA) bits to row address(RA) bits mappings are:
444  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
445  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
446  */
447 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
448 		unsigned long *pfn, unsigned long *offset, int *csrow)
449 {
450 	u32 bcnt, rank, col, bank, row;
451 	u32 c;
452 	unsigned long pa;
453 	int i;
454 
455 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
456 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
457 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
458 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
459 	row = mear & MEAR_ROW_MASK;
460 
461 	*csrow = rank;
462 
463 #ifdef CONFIG_EDAC_DEBUG
464 	if (mci->csrows[rank]->first_page == 0) {
465 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
466 			"non-populated csrow, broken hardware?\n");
467 		return;
468 	}
469 #endif
470 
471 	/* Revert csrow number */
472 	pa = mci->csrows[rank]->first_page << PAGE_SHIFT;
473 
474 	/* Revert column address */
475 	col += bcnt;
476 	for (i = 0; i < 11; i++) {
477 		c = col & 0x1;
478 		col >>= 1;
479 		pa |= c << (14 - i);
480 	}
481 
482 	/* Revert bank address */
483 	pa |= bank << 19;
484 
485 	/* Revert row address, in 4 steps */
486 	for (i = 0; i < 3; i++) {
487 		c = row & 0x1;
488 		row >>= 1;
489 		pa |= c << (26 - i);
490 	}
491 
492 	for (i = 0; i < 3; i++) {
493 		c = row & 0x1;
494 		row >>= 1;
495 		pa |= c << (21 + i);
496 	}
497 
498 	for (i = 0; i < 4; i++) {
499 		c = row & 0x1;
500 		row >>= 1;
501 		pa |= c << (18 - i);
502 	}
503 
504 	for (i = 0; i < 3; i++) {
505 		c = row & 0x1;
506 		row >>= 1;
507 		pa |= c << (29 - i);
508 	}
509 
510 	*offset = pa & (PAGE_SIZE - 1);
511 	*pfn = pa >> PAGE_SHIFT;
512 
513 	edac_dbg(0, "ECC physical address 0x%lx\n", pa);
514 }
515 
516 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
517 {
518 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
519 		return 0;
520 
521 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
522 		return 1;
523 
524 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
525 			 syndrome);
526 	return 1;
527 }
528 
529 /* Check memory controller registers for ECC errors */
530 static void cpc925_mc_check(struct mem_ctl_info *mci)
531 {
532 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
533 	u32 apiexcp;
534 	u32 mear;
535 	u32 mesr;
536 	u16 syndrome;
537 	unsigned long pfn = 0, offset = 0;
538 	int csrow = 0, channel = 0;
539 
540 	/* APIEXCP is cleared when read */
541 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
542 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
543 		return;
544 
545 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
546 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
547 
548 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
549 
550 	/* Revert column/row addresses into page frame number, etc */
551 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
552 
553 	if (apiexcp & CECC_EXCP_DETECTED) {
554 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
555 		channel = cpc925_mc_find_channel(mci, syndrome);
556 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
557 				     pfn, offset, syndrome,
558 				     csrow, channel, -1,
559 				     mci->ctl_name, "");
560 	}
561 
562 	if (apiexcp & UECC_EXCP_DETECTED) {
563 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
564 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
565 				     pfn, offset, 0,
566 				     csrow, -1, -1,
567 				     mci->ctl_name, "");
568 	}
569 
570 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
571 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
572 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
573 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
574 		apiexcp);
575 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
576 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
577 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
578 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
579 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
580 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
581 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
582 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
583 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
584 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
585 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
586 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
587 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
588 		mesr);
589 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
590 		syndrome);
591 }
592 
593 /******************** CPU err device********************************/
594 static u32 cpc925_cpu_mask_disabled(void)
595 {
596 	struct device_node *cpunode;
597 	static u32 mask = 0;
598 
599 	/* use cached value if available */
600 	if (mask != 0)
601 		return mask;
602 
603 	mask = APIMASK_ADI0 | APIMASK_ADI1;
604 
605 	for_each_of_cpu_node(cpunode) {
606 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
607 		if (reg == NULL || *reg > 2) {
608 			cpc925_printk(KERN_ERR, "Bad reg value at %pOF\n", cpunode);
609 			continue;
610 		}
611 
612 		mask &= ~APIMASK_ADI(*reg);
613 	}
614 
615 	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
616 		/* We assume that each CPU sits on it's own PI and that
617 		 * for present CPUs the reg property equals to the PI
618 		 * interface id */
619 		cpc925_printk(KERN_WARNING,
620 				"Assuming PI id is equal to CPU MPIC id!\n");
621 	}
622 
623 	return mask;
624 }
625 
626 /* Enable CPU Errors detection */
627 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
628 {
629 	u32 apimask;
630 	u32 cpumask;
631 
632 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
633 
634 	cpumask = cpc925_cpu_mask_disabled();
635 	if (apimask & cpumask) {
636 		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
637 				"but enabled in APIMASK, disabling\n");
638 		apimask &= ~cpumask;
639 	}
640 
641 	if ((apimask & CPU_MASK_ENABLE) == 0)
642 		apimask |= CPU_MASK_ENABLE;
643 
644 	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
645 }
646 
647 /* Disable CPU Errors detection */
648 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
649 {
650 	/*
651 	 * WARNING:
652 	 * We are supposed to clear the CPU error detection bits,
653 	 * and it will be no problem to do so. However, once they
654 	 * are cleared here if we want to re-install CPC925 EDAC
655 	 * module later, setting them up in cpc925_cpu_init() will
656 	 * trigger machine check exception.
657 	 * Also, it's ok to leave CPU error detection bits enabled,
658 	 * since they are reset to 1 by default.
659 	 */
660 
661 	return;
662 }
663 
664 /* Check for CPU Errors */
665 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
666 {
667 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
668 	u32 apiexcp;
669 	u32 apimask;
670 
671 	/* APIEXCP is cleared when read */
672 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
673 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
674 		return;
675 
676 	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
677 		return;
678 
679 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
680 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
681 				 "Processor Interface register dump:\n");
682 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
683 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
684 
685 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
686 }
687 
688 /******************** HT Link err device****************************/
689 /* Enable HyperTransport Link Error detection */
690 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
691 {
692 	u32 ht_errctrl;
693 
694 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
695 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
696 		ht_errctrl |= HT_ERRCTRL_ENABLE;
697 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
698 	}
699 }
700 
701 /* Disable HyperTransport Link Error detection */
702 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
703 {
704 	u32 ht_errctrl;
705 
706 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
707 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
708 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
709 }
710 
711 /* Check for HyperTransport Link errors */
712 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
713 {
714 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
715 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
716 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
717 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
718 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
719 
720 	if (!((brgctrl & BRGCTRL_DETSERR) ||
721 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
722 	      (errctrl & HT_ERRCTRL_DETECTED) ||
723 	      (linkerr & HT_LINKERR_DETECTED)))
724 		return;
725 
726 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
727 				 "HT register dump:\n");
728 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
729 		      brgctrl);
730 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
731 		      linkctrl);
732 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
733 		      errctrl);
734 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
735 		      linkerr);
736 
737 	/* Clear by write 1 */
738 	if (brgctrl & BRGCTRL_DETSERR)
739 		__raw_writel(BRGCTRL_DETSERR,
740 				dev_info->vbase + REG_BRGCTRL_OFFSET);
741 
742 	if (linkctrl & HT_LINKCTRL_DETECTED)
743 		__raw_writel(HT_LINKCTRL_DETECTED,
744 				dev_info->vbase + REG_LINKCTRL_OFFSET);
745 
746 	/* Initiate Secondary Bus Reset to clear the chain failure */
747 	if (errctrl & ERRCTRL_CHN_FAL)
748 		__raw_writel(BRGCTRL_SECBUSRESET,
749 				dev_info->vbase + REG_BRGCTRL_OFFSET);
750 
751 	if (errctrl & ERRCTRL_RSP_ERR)
752 		__raw_writel(ERRCTRL_RSP_ERR,
753 				dev_info->vbase + REG_ERRCTRL_OFFSET);
754 
755 	if (linkerr & HT_LINKERR_DETECTED)
756 		__raw_writel(HT_LINKERR_DETECTED,
757 				dev_info->vbase + REG_LINKERR_OFFSET);
758 
759 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
760 }
761 
762 static struct cpc925_dev_info cpc925_devs[] = {
763 	{
764 	.ctl_name = CPC925_CPU_ERR_DEV,
765 	.init = cpc925_cpu_init,
766 	.exit = cpc925_cpu_exit,
767 	.check = cpc925_cpu_check,
768 	},
769 	{
770 	.ctl_name = CPC925_HT_LINK_DEV,
771 	.init = cpc925_htlink_init,
772 	.exit = cpc925_htlink_exit,
773 	.check = cpc925_htlink_check,
774 	},
775 	{ }
776 };
777 
778 /*
779  * Add CPU Err detection and HyperTransport Link Err detection
780  * as common "edac_device", they have no corresponding device
781  * nodes in the Open Firmware DTB and we have to add platform
782  * devices for them. Also, they will share the MMIO with that
783  * of memory controller.
784  */
785 static void cpc925_add_edac_devices(void __iomem *vbase)
786 {
787 	struct cpc925_dev_info *dev_info;
788 
789 	if (!vbase) {
790 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
791 		return;
792 	}
793 
794 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
795 		dev_info->vbase = vbase;
796 		dev_info->pdev = platform_device_register_simple(
797 					dev_info->ctl_name, 0, NULL, 0);
798 		if (IS_ERR(dev_info->pdev)) {
799 			cpc925_printk(KERN_ERR,
800 				"Can't register platform device for %s\n",
801 				dev_info->ctl_name);
802 			continue;
803 		}
804 
805 		/*
806 		 * Don't have to allocate private structure but
807 		 * make use of cpc925_devs[] instead.
808 		 */
809 		dev_info->edac_idx = edac_device_alloc_index();
810 		dev_info->edac_dev =
811 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
812 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
813 		if (!dev_info->edac_dev) {
814 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
815 			goto err1;
816 		}
817 
818 		dev_info->edac_dev->pvt_info = dev_info;
819 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
820 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
821 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
822 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
823 
824 		if (edac_op_state == EDAC_OPSTATE_POLL)
825 			dev_info->edac_dev->edac_check = dev_info->check;
826 
827 		if (dev_info->init)
828 			dev_info->init(dev_info);
829 
830 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
831 			cpc925_printk(KERN_ERR,
832 				"Unable to add edac device for %s\n",
833 				dev_info->ctl_name);
834 			goto err2;
835 		}
836 
837 		edac_dbg(0, "Successfully added edac device for %s\n",
838 			 dev_info->ctl_name);
839 
840 		continue;
841 
842 err2:
843 		if (dev_info->exit)
844 			dev_info->exit(dev_info);
845 		edac_device_free_ctl_info(dev_info->edac_dev);
846 err1:
847 		platform_device_unregister(dev_info->pdev);
848 	}
849 }
850 
851 /*
852  * Delete the common "edac_device" for CPU Err Detection
853  * and HyperTransport Link Err Detection
854  */
855 static void cpc925_del_edac_devices(void)
856 {
857 	struct cpc925_dev_info *dev_info;
858 
859 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
860 		if (dev_info->edac_dev) {
861 			edac_device_del_device(dev_info->edac_dev->dev);
862 			edac_device_free_ctl_info(dev_info->edac_dev);
863 			platform_device_unregister(dev_info->pdev);
864 		}
865 
866 		if (dev_info->exit)
867 			dev_info->exit(dev_info);
868 
869 		edac_dbg(0, "Successfully deleted edac device for %s\n",
870 			 dev_info->ctl_name);
871 	}
872 }
873 
874 /* Convert current back-ground scrub rate into byte/sec bandwidth */
875 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
876 {
877 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
878 	int bw;
879 	u32 mscr;
880 	u8 si;
881 
882 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
883 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
884 
885 	edac_dbg(0, "Mem Scrub Ctrl Register 0x%x\n", mscr);
886 
887 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
888 	    (si == 0)) {
889 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
890 		bw = 0;
891 	} else
892 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
893 
894 	return bw;
895 }
896 
897 /* Return 0 for single channel; 1 for dual channel */
898 static int cpc925_mc_get_channels(void __iomem *vbase)
899 {
900 	int dual = 0;
901 	u32 mbcr;
902 
903 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
904 
905 	/*
906 	 * Dual channel only when 128-bit wide physical bus
907 	 * and 128-bit configuration.
908 	 */
909 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
910 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
911 		dual = 1;
912 
913 	edac_dbg(0, "%s channel\n", (dual > 0) ? "Dual" : "Single");
914 
915 	return dual;
916 }
917 
918 static int cpc925_probe(struct platform_device *pdev)
919 {
920 	static int edac_mc_idx;
921 	struct mem_ctl_info *mci;
922 	struct edac_mc_layer layers[2];
923 	void __iomem *vbase;
924 	struct cpc925_mc_pdata *pdata;
925 	struct resource *r;
926 	int res = 0, nr_channels;
927 
928 	edac_dbg(0, "%s platform device found!\n", pdev->name);
929 
930 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
931 		res = -ENOMEM;
932 		goto out;
933 	}
934 
935 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
936 	if (!r) {
937 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
938 		res = -ENOENT;
939 		goto err1;
940 	}
941 
942 	if (!devm_request_mem_region(&pdev->dev,
943 				     r->start,
944 				     resource_size(r),
945 				     pdev->name)) {
946 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
947 		res = -EBUSY;
948 		goto err1;
949 	}
950 
951 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
952 	if (!vbase) {
953 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
954 		res = -ENOMEM;
955 		goto err2;
956 	}
957 
958 	nr_channels = cpc925_mc_get_channels(vbase) + 1;
959 
960 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
961 	layers[0].size = CPC925_NR_CSROWS;
962 	layers[0].is_virt_csrow = true;
963 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
964 	layers[1].size = nr_channels;
965 	layers[1].is_virt_csrow = false;
966 	mci = edac_mc_alloc(edac_mc_idx, ARRAY_SIZE(layers), layers,
967 			    sizeof(struct cpc925_mc_pdata));
968 	if (!mci) {
969 		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
970 		res = -ENOMEM;
971 		goto err2;
972 	}
973 
974 	pdata = mci->pvt_info;
975 	pdata->vbase = vbase;
976 	pdata->edac_idx = edac_mc_idx++;
977 	pdata->name = pdev->name;
978 
979 	mci->pdev = &pdev->dev;
980 	platform_set_drvdata(pdev, mci);
981 	mci->dev_name = dev_name(&pdev->dev);
982 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
983 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
984 	mci->edac_cap = EDAC_FLAG_SECDED;
985 	mci->mod_name = CPC925_EDAC_MOD_STR;
986 	mci->ctl_name = pdev->name;
987 
988 	if (edac_op_state == EDAC_OPSTATE_POLL)
989 		mci->edac_check = cpc925_mc_check;
990 
991 	mci->ctl_page_to_phys = NULL;
992 	mci->scrub_mode = SCRUB_SW_SRC;
993 	mci->set_sdram_scrub_rate = NULL;
994 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
995 
996 	cpc925_init_csrows(mci);
997 
998 	/* Setup memory controller registers */
999 	cpc925_mc_init(mci);
1000 
1001 	if (edac_mc_add_mc(mci) > 0) {
1002 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
1003 		goto err3;
1004 	}
1005 
1006 	cpc925_add_edac_devices(vbase);
1007 
1008 	/* get this far and it's successful */
1009 	edac_dbg(0, "success\n");
1010 
1011 	res = 0;
1012 	goto out;
1013 
1014 err3:
1015 	cpc925_mc_exit(mci);
1016 	edac_mc_free(mci);
1017 err2:
1018 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
1019 err1:
1020 	devres_release_group(&pdev->dev, cpc925_probe);
1021 out:
1022 	return res;
1023 }
1024 
1025 static int cpc925_remove(struct platform_device *pdev)
1026 {
1027 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
1028 
1029 	/*
1030 	 * Delete common edac devices before edac mc, because
1031 	 * the former share the MMIO of the latter.
1032 	 */
1033 	cpc925_del_edac_devices();
1034 	cpc925_mc_exit(mci);
1035 
1036 	edac_mc_del_mc(&pdev->dev);
1037 	edac_mc_free(mci);
1038 
1039 	return 0;
1040 }
1041 
1042 static struct platform_driver cpc925_edac_driver = {
1043 	.probe = cpc925_probe,
1044 	.remove = cpc925_remove,
1045 	.driver = {
1046 		   .name = "cpc925_edac",
1047 	}
1048 };
1049 
1050 static int __init cpc925_edac_init(void)
1051 {
1052 	int ret = 0;
1053 
1054 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
1055 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
1056 
1057 	/* Only support POLL mode so far */
1058 	edac_op_state = EDAC_OPSTATE_POLL;
1059 
1060 	ret = platform_driver_register(&cpc925_edac_driver);
1061 	if (ret) {
1062 		printk(KERN_WARNING "Failed to register %s\n",
1063 			CPC925_EDAC_MOD_STR);
1064 	}
1065 
1066 	return ret;
1067 }
1068 
1069 static void __exit cpc925_edac_exit(void)
1070 {
1071 	platform_driver_unregister(&cpc925_edac_driver);
1072 }
1073 
1074 module_init(cpc925_edac_init);
1075 module_exit(cpc925_edac_exit);
1076 
1077 MODULE_LICENSE("GPL");
1078 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1079 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1080