xref: /openbmc/linux/drivers/edac/cpc925_edac.c (revision 7490ca1e)
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 	int index;
333 	u32 mbmr, mbbar, bba;
334 	unsigned long row_size, 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 		csrow->nr_pages = row_size >> PAGE_SHIFT;
354 		csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
355 		last_nr_pages = csrow->last_page + 1;
356 
357 		csrow->mtype = MEM_RDDR;
358 		csrow->edac_mode = EDAC_SECDED;
359 
360 		switch (csrow->nr_channels) {
361 		case 1: /* Single channel */
362 			csrow->grain = 32; /* four-beat burst of 32 bytes */
363 			break;
364 		case 2: /* Dual channel */
365 		default:
366 			csrow->grain = 64; /* four-beat burst of 64 bytes */
367 			break;
368 		}
369 
370 		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
371 		case 6: /* 0110, no way to differentiate X8 VS X16 */
372 		case 5:	/* 0101 */
373 		case 8: /* 1000 */
374 			csrow->dtype = DEV_X16;
375 			break;
376 		case 7: /* 0111 */
377 		case 9: /* 1001 */
378 			csrow->dtype = DEV_X8;
379 			break;
380 		default:
381 			csrow->dtype = DEV_UNKNOWN;
382 			break;
383 		}
384 	}
385 }
386 
387 /* Enable memory controller ECC detection */
388 static void cpc925_mc_init(struct mem_ctl_info *mci)
389 {
390 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
391 	u32 apimask;
392 	u32 mccr;
393 
394 	/* Enable various ECC error exceptions */
395 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
396 	if ((apimask & ECC_MASK_ENABLE) == 0) {
397 		apimask |= ECC_MASK_ENABLE;
398 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
399 	}
400 
401 	/* Enable ECC detection */
402 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
403 	if ((mccr & MCCR_ECC_EN) == 0) {
404 		mccr |= MCCR_ECC_EN;
405 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
406 	}
407 }
408 
409 /* Disable memory controller ECC detection */
410 static void cpc925_mc_exit(struct mem_ctl_info *mci)
411 {
412 	/*
413 	 * WARNING:
414 	 * We are supposed to clear the ECC error detection bits,
415 	 * and it will be no problem to do so. However, once they
416 	 * are cleared here if we want to re-install CPC925 EDAC
417 	 * module later, setting them up in cpc925_mc_init() will
418 	 * trigger machine check exception.
419 	 * Also, it's ok to leave ECC error detection bits enabled,
420 	 * since they are reset to 1 by default or by boot loader.
421 	 */
422 
423 	return;
424 }
425 
426 /*
427  * Revert DDR column/row/bank addresses into page frame number and
428  * offset in page.
429  *
430  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
431  * physical address(PA) bits to column address(CA) bits mappings are:
432  * CA	0   1   2   3   4   5   6   7   8   9   10
433  * PA	59  58  57  56  55  54  53  52  51  50  49
434  *
435  * physical address(PA) bits to bank address(BA) bits mappings are:
436  * BA	0   1
437  * PA	43  44
438  *
439  * physical address(PA) bits to row address(RA) bits mappings are:
440  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
441  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
442  */
443 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
444 		unsigned long *pfn, unsigned long *offset, int *csrow)
445 {
446 	u32 bcnt, rank, col, bank, row;
447 	u32 c;
448 	unsigned long pa;
449 	int i;
450 
451 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
452 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
453 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
454 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
455 	row = mear & MEAR_ROW_MASK;
456 
457 	*csrow = rank;
458 
459 #ifdef CONFIG_EDAC_DEBUG
460 	if (mci->csrows[rank].first_page == 0) {
461 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
462 			"non-populated csrow, broken hardware?\n");
463 		return;
464 	}
465 #endif
466 
467 	/* Revert csrow number */
468 	pa = mci->csrows[rank].first_page << PAGE_SHIFT;
469 
470 	/* Revert column address */
471 	col += bcnt;
472 	for (i = 0; i < 11; i++) {
473 		c = col & 0x1;
474 		col >>= 1;
475 		pa |= c << (14 - i);
476 	}
477 
478 	/* Revert bank address */
479 	pa |= bank << 19;
480 
481 	/* Revert row address, in 4 steps */
482 	for (i = 0; i < 3; i++) {
483 		c = row & 0x1;
484 		row >>= 1;
485 		pa |= c << (26 - i);
486 	}
487 
488 	for (i = 0; i < 3; i++) {
489 		c = row & 0x1;
490 		row >>= 1;
491 		pa |= c << (21 + i);
492 	}
493 
494 	for (i = 0; i < 4; i++) {
495 		c = row & 0x1;
496 		row >>= 1;
497 		pa |= c << (18 - i);
498 	}
499 
500 	for (i = 0; i < 3; i++) {
501 		c = row & 0x1;
502 		row >>= 1;
503 		pa |= c << (29 - i);
504 	}
505 
506 	*offset = pa & (PAGE_SIZE - 1);
507 	*pfn = pa >> PAGE_SHIFT;
508 
509 	debugf0("%s: ECC physical address 0x%lx\n", __func__, pa);
510 }
511 
512 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
513 {
514 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
515 		return 0;
516 
517 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
518 		return 1;
519 
520 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
521 			 syndrome);
522 	return 1;
523 }
524 
525 /* Check memory controller registers for ECC errors */
526 static void cpc925_mc_check(struct mem_ctl_info *mci)
527 {
528 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
529 	u32 apiexcp;
530 	u32 mear;
531 	u32 mesr;
532 	u16 syndrome;
533 	unsigned long pfn = 0, offset = 0;
534 	int csrow = 0, channel = 0;
535 
536 	/* APIEXCP is cleared when read */
537 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
538 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
539 		return;
540 
541 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
542 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
543 
544 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
545 
546 	/* Revert column/row addresses into page frame number, etc */
547 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
548 
549 	if (apiexcp & CECC_EXCP_DETECTED) {
550 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
551 		channel = cpc925_mc_find_channel(mci, syndrome);
552 		edac_mc_handle_ce(mci, pfn, offset, syndrome,
553 				  csrow, channel, mci->ctl_name);
554 	}
555 
556 	if (apiexcp & UECC_EXCP_DETECTED) {
557 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
558 		edac_mc_handle_ue(mci, pfn, offset, csrow, mci->ctl_name);
559 	}
560 
561 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
562 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
563 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
564 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
565 		apiexcp);
566 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
567 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
568 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
569 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
570 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
571 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
572 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
573 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
574 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
575 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
576 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
577 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
578 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
579 		mesr);
580 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
581 		syndrome);
582 }
583 
584 /******************** CPU err device********************************/
585 static u32 cpc925_cpu_mask_disabled(void)
586 {
587 	struct device_node *cpus;
588 	struct device_node *cpunode = NULL;
589 	static u32 mask = 0;
590 
591 	/* use cached value if available */
592 	if (mask != 0)
593 		return mask;
594 
595 	mask = APIMASK_ADI0 | APIMASK_ADI1;
596 
597 	cpus = of_find_node_by_path("/cpus");
598 	if (cpus == NULL) {
599 		cpc925_printk(KERN_DEBUG, "No /cpus node !\n");
600 		return 0;
601 	}
602 
603 	while ((cpunode = of_get_next_child(cpus, cpunode)) != NULL) {
604 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
605 
606 		if (strcmp(cpunode->type, "cpu")) {
607 			cpc925_printk(KERN_ERR, "Not a cpu node in /cpus: %s\n", cpunode->name);
608 			continue;
609 		}
610 
611 		if (reg == NULL || *reg > 2) {
612 			cpc925_printk(KERN_ERR, "Bad reg value at %s\n", cpunode->full_name);
613 			continue;
614 		}
615 
616 		mask &= ~APIMASK_ADI(*reg);
617 	}
618 
619 	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
620 		/* We assume that each CPU sits on it's own PI and that
621 		 * for present CPUs the reg property equals to the PI
622 		 * interface id */
623 		cpc925_printk(KERN_WARNING,
624 				"Assuming PI id is equal to CPU MPIC id!\n");
625 	}
626 
627 	of_node_put(cpunode);
628 	of_node_put(cpus);
629 
630 	return mask;
631 }
632 
633 /* Enable CPU Errors detection */
634 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
635 {
636 	u32 apimask;
637 	u32 cpumask;
638 
639 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
640 
641 	cpumask = cpc925_cpu_mask_disabled();
642 	if (apimask & cpumask) {
643 		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
644 				"but enabled in APIMASK, disabling\n");
645 		apimask &= ~cpumask;
646 	}
647 
648 	if ((apimask & CPU_MASK_ENABLE) == 0)
649 		apimask |= CPU_MASK_ENABLE;
650 
651 	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
652 }
653 
654 /* Disable CPU Errors detection */
655 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
656 {
657 	/*
658 	 * WARNING:
659 	 * We are supposed to clear the CPU error detection bits,
660 	 * and it will be no problem to do so. However, once they
661 	 * are cleared here if we want to re-install CPC925 EDAC
662 	 * module later, setting them up in cpc925_cpu_init() will
663 	 * trigger machine check exception.
664 	 * Also, it's ok to leave CPU error detection bits enabled,
665 	 * since they are reset to 1 by default.
666 	 */
667 
668 	return;
669 }
670 
671 /* Check for CPU Errors */
672 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
673 {
674 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
675 	u32 apiexcp;
676 	u32 apimask;
677 
678 	/* APIEXCP is cleared when read */
679 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
680 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
681 		return;
682 
683 	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
684 		return;
685 
686 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
687 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
688 				 "Processor Interface register dump:\n");
689 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
690 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
691 
692 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
693 }
694 
695 /******************** HT Link err device****************************/
696 /* Enable HyperTransport Link Error detection */
697 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
698 {
699 	u32 ht_errctrl;
700 
701 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
702 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
703 		ht_errctrl |= HT_ERRCTRL_ENABLE;
704 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
705 	}
706 }
707 
708 /* Disable HyperTransport Link Error detection */
709 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
710 {
711 	u32 ht_errctrl;
712 
713 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
714 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
715 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
716 }
717 
718 /* Check for HyperTransport Link errors */
719 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
720 {
721 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
722 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
723 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
724 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
725 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
726 
727 	if (!((brgctrl & BRGCTRL_DETSERR) ||
728 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
729 	      (errctrl & HT_ERRCTRL_DETECTED) ||
730 	      (linkerr & HT_LINKERR_DETECTED)))
731 		return;
732 
733 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
734 				 "HT register dump:\n");
735 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
736 		      brgctrl);
737 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
738 		      linkctrl);
739 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
740 		      errctrl);
741 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
742 		      linkerr);
743 
744 	/* Clear by write 1 */
745 	if (brgctrl & BRGCTRL_DETSERR)
746 		__raw_writel(BRGCTRL_DETSERR,
747 				dev_info->vbase + REG_BRGCTRL_OFFSET);
748 
749 	if (linkctrl & HT_LINKCTRL_DETECTED)
750 		__raw_writel(HT_LINKCTRL_DETECTED,
751 				dev_info->vbase + REG_LINKCTRL_OFFSET);
752 
753 	/* Initiate Secondary Bus Reset to clear the chain failure */
754 	if (errctrl & ERRCTRL_CHN_FAL)
755 		__raw_writel(BRGCTRL_SECBUSRESET,
756 				dev_info->vbase + REG_BRGCTRL_OFFSET);
757 
758 	if (errctrl & ERRCTRL_RSP_ERR)
759 		__raw_writel(ERRCTRL_RSP_ERR,
760 				dev_info->vbase + REG_ERRCTRL_OFFSET);
761 
762 	if (linkerr & HT_LINKERR_DETECTED)
763 		__raw_writel(HT_LINKERR_DETECTED,
764 				dev_info->vbase + REG_LINKERR_OFFSET);
765 
766 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
767 }
768 
769 static struct cpc925_dev_info cpc925_devs[] = {
770 	{
771 	.ctl_name = CPC925_CPU_ERR_DEV,
772 	.init = cpc925_cpu_init,
773 	.exit = cpc925_cpu_exit,
774 	.check = cpc925_cpu_check,
775 	},
776 	{
777 	.ctl_name = CPC925_HT_LINK_DEV,
778 	.init = cpc925_htlink_init,
779 	.exit = cpc925_htlink_exit,
780 	.check = cpc925_htlink_check,
781 	},
782 	{0}, /* Terminated by NULL */
783 };
784 
785 /*
786  * Add CPU Err detection and HyperTransport Link Err detection
787  * as common "edac_device", they have no corresponding device
788  * nodes in the Open Firmware DTB and we have to add platform
789  * devices for them. Also, they will share the MMIO with that
790  * of memory controller.
791  */
792 static void cpc925_add_edac_devices(void __iomem *vbase)
793 {
794 	struct cpc925_dev_info *dev_info;
795 
796 	if (!vbase) {
797 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
798 		return;
799 	}
800 
801 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
802 		dev_info->vbase = vbase;
803 		dev_info->pdev = platform_device_register_simple(
804 					dev_info->ctl_name, 0, NULL, 0);
805 		if (IS_ERR(dev_info->pdev)) {
806 			cpc925_printk(KERN_ERR,
807 				"Can't register platform device for %s\n",
808 				dev_info->ctl_name);
809 			continue;
810 		}
811 
812 		/*
813 		 * Don't have to allocate private structure but
814 		 * make use of cpc925_devs[] instead.
815 		 */
816 		dev_info->edac_idx = edac_device_alloc_index();
817 		dev_info->edac_dev =
818 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
819 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
820 		if (!dev_info->edac_dev) {
821 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
822 			goto err1;
823 		}
824 
825 		dev_info->edac_dev->pvt_info = dev_info;
826 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
827 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
828 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
829 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
830 
831 		if (edac_op_state == EDAC_OPSTATE_POLL)
832 			dev_info->edac_dev->edac_check = dev_info->check;
833 
834 		if (dev_info->init)
835 			dev_info->init(dev_info);
836 
837 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
838 			cpc925_printk(KERN_ERR,
839 				"Unable to add edac device for %s\n",
840 				dev_info->ctl_name);
841 			goto err2;
842 		}
843 
844 		debugf0("%s: Successfully added edac device for %s\n",
845 			__func__, dev_info->ctl_name);
846 
847 		continue;
848 
849 err2:
850 		if (dev_info->exit)
851 			dev_info->exit(dev_info);
852 		edac_device_free_ctl_info(dev_info->edac_dev);
853 err1:
854 		platform_device_unregister(dev_info->pdev);
855 	}
856 }
857 
858 /*
859  * Delete the common "edac_device" for CPU Err Detection
860  * and HyperTransport Link Err Detection
861  */
862 static void cpc925_del_edac_devices(void)
863 {
864 	struct cpc925_dev_info *dev_info;
865 
866 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
867 		if (dev_info->edac_dev) {
868 			edac_device_del_device(dev_info->edac_dev->dev);
869 			edac_device_free_ctl_info(dev_info->edac_dev);
870 			platform_device_unregister(dev_info->pdev);
871 		}
872 
873 		if (dev_info->exit)
874 			dev_info->exit(dev_info);
875 
876 		debugf0("%s: Successfully deleted edac device for %s\n",
877 			__func__, dev_info->ctl_name);
878 	}
879 }
880 
881 /* Convert current back-ground scrub rate into byte/sec bandwidth */
882 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
883 {
884 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
885 	int bw;
886 	u32 mscr;
887 	u8 si;
888 
889 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
890 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
891 
892 	debugf0("%s, Mem Scrub Ctrl Register 0x%x\n", __func__, mscr);
893 
894 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
895 	    (si == 0)) {
896 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
897 		bw = 0;
898 	} else
899 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
900 
901 	return bw;
902 }
903 
904 /* Return 0 for single channel; 1 for dual channel */
905 static int cpc925_mc_get_channels(void __iomem *vbase)
906 {
907 	int dual = 0;
908 	u32 mbcr;
909 
910 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
911 
912 	/*
913 	 * Dual channel only when 128-bit wide physical bus
914 	 * and 128-bit configuration.
915 	 */
916 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
917 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
918 		dual = 1;
919 
920 	debugf0("%s: %s channel\n", __func__,
921 		(dual > 0) ? "Dual" : "Single");
922 
923 	return dual;
924 }
925 
926 static int __devinit cpc925_probe(struct platform_device *pdev)
927 {
928 	static int edac_mc_idx;
929 	struct mem_ctl_info *mci;
930 	void __iomem *vbase;
931 	struct cpc925_mc_pdata *pdata;
932 	struct resource *r;
933 	int res = 0, nr_channels;
934 
935 	debugf0("%s: %s platform device found!\n", __func__, pdev->name);
936 
937 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
938 		res = -ENOMEM;
939 		goto out;
940 	}
941 
942 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
943 	if (!r) {
944 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
945 		res = -ENOENT;
946 		goto err1;
947 	}
948 
949 	if (!devm_request_mem_region(&pdev->dev,
950 				     r->start,
951 				     resource_size(r),
952 				     pdev->name)) {
953 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
954 		res = -EBUSY;
955 		goto err1;
956 	}
957 
958 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
959 	if (!vbase) {
960 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
961 		res = -ENOMEM;
962 		goto err2;
963 	}
964 
965 	nr_channels = cpc925_mc_get_channels(vbase);
966 	mci = edac_mc_alloc(sizeof(struct cpc925_mc_pdata),
967 			CPC925_NR_CSROWS, nr_channels + 1, edac_mc_idx);
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->dev = &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->mod_ver = CPC925_EDAC_REVISION;
987 	mci->ctl_name = pdev->name;
988 
989 	if (edac_op_state == EDAC_OPSTATE_POLL)
990 		mci->edac_check = cpc925_mc_check;
991 
992 	mci->ctl_page_to_phys = NULL;
993 	mci->scrub_mode = SCRUB_SW_SRC;
994 	mci->set_sdram_scrub_rate = NULL;
995 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
996 
997 	cpc925_init_csrows(mci);
998 
999 	/* Setup memory controller registers */
1000 	cpc925_mc_init(mci);
1001 
1002 	if (edac_mc_add_mc(mci) > 0) {
1003 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
1004 		goto err3;
1005 	}
1006 
1007 	cpc925_add_edac_devices(vbase);
1008 
1009 	/* get this far and it's successful */
1010 	debugf0("%s: success\n", __func__);
1011 
1012 	res = 0;
1013 	goto out;
1014 
1015 err3:
1016 	cpc925_mc_exit(mci);
1017 	edac_mc_free(mci);
1018 err2:
1019 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
1020 err1:
1021 	devres_release_group(&pdev->dev, cpc925_probe);
1022 out:
1023 	return res;
1024 }
1025 
1026 static int cpc925_remove(struct platform_device *pdev)
1027 {
1028 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
1029 
1030 	/*
1031 	 * Delete common edac devices before edac mc, because
1032 	 * the former share the MMIO of the latter.
1033 	 */
1034 	cpc925_del_edac_devices();
1035 	cpc925_mc_exit(mci);
1036 
1037 	edac_mc_del_mc(&pdev->dev);
1038 	edac_mc_free(mci);
1039 
1040 	return 0;
1041 }
1042 
1043 static struct platform_driver cpc925_edac_driver = {
1044 	.probe = cpc925_probe,
1045 	.remove = cpc925_remove,
1046 	.driver = {
1047 		   .name = "cpc925_edac",
1048 	}
1049 };
1050 
1051 static int __init cpc925_edac_init(void)
1052 {
1053 	int ret = 0;
1054 
1055 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
1056 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
1057 
1058 	/* Only support POLL mode so far */
1059 	edac_op_state = EDAC_OPSTATE_POLL;
1060 
1061 	ret = platform_driver_register(&cpc925_edac_driver);
1062 	if (ret) {
1063 		printk(KERN_WARNING "Failed to register %s\n",
1064 			CPC925_EDAC_MOD_STR);
1065 	}
1066 
1067 	return ret;
1068 }
1069 
1070 static void __exit cpc925_edac_exit(void)
1071 {
1072 	platform_driver_unregister(&cpc925_edac_driver);
1073 }
1074 
1075 module_init(cpc925_edac_init);
1076 module_exit(cpc925_edac_exit);
1077 
1078 MODULE_LICENSE("GPL");
1079 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1080 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1081