xref: /openbmc/linux/drivers/edac/cpc925_edac.c (revision 8ac727c1)
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 " __DATE__
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 
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 		debugf1("%s: start 0x%lx, size 0x%lx\n", __func__,
319 			start, size);
320 		pdata->total_mem += size;
321 	} while (reg < reg_end);
322 
323 	of_node_put(np);
324 	debugf0("%s: total_mem 0x%lx\n", __func__, 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 	int index;
332 	u32 mbmr, mbbar, bba;
333 	unsigned long row_size, last_nr_pages = 0;
334 
335 	get_total_mem(pdata);
336 
337 	for (index = 0; index < mci->nr_csrows; index++) {
338 		mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
339 				   0x20 * index);
340 		mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
341 				   0x20 + index);
342 		bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
343 		       ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);
344 
345 		if (bba == 0)
346 			continue; /* not populated */
347 
348 		csrow = &mci->csrows[index];
349 
350 		row_size = bba * (1UL << 28);	/* 256M */
351 		csrow->first_page = last_nr_pages;
352 		csrow->nr_pages = row_size >> PAGE_SHIFT;
353 		csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
354 		last_nr_pages = csrow->last_page + 1;
355 
356 		csrow->mtype = MEM_RDDR;
357 		csrow->edac_mode = EDAC_SECDED;
358 
359 		switch (csrow->nr_channels) {
360 		case 1: /* Single channel */
361 			csrow->grain = 32; /* four-beat burst of 32 bytes */
362 			break;
363 		case 2: /* Dual channel */
364 		default:
365 			csrow->grain = 64; /* four-beat burst of 64 bytes */
366 			break;
367 		}
368 
369 		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
370 		case 6: /* 0110, no way to differentiate X8 VS X16 */
371 		case 5:	/* 0101 */
372 		case 8: /* 1000 */
373 			csrow->dtype = DEV_X16;
374 			break;
375 		case 7: /* 0111 */
376 		case 9: /* 1001 */
377 			csrow->dtype = DEV_X8;
378 			break;
379 		default:
380 			csrow->dtype = DEV_UNKNOWN;
381 			break;
382 		}
383 	}
384 }
385 
386 /* Enable memory controller ECC detection */
387 static void cpc925_mc_init(struct mem_ctl_info *mci)
388 {
389 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
390 	u32 apimask;
391 	u32 mccr;
392 
393 	/* Enable various ECC error exceptions */
394 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
395 	if ((apimask & ECC_MASK_ENABLE) == 0) {
396 		apimask |= ECC_MASK_ENABLE;
397 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
398 	}
399 
400 	/* Enable ECC detection */
401 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
402 	if ((mccr & MCCR_ECC_EN) == 0) {
403 		mccr |= MCCR_ECC_EN;
404 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
405 	}
406 }
407 
408 /* Disable memory controller ECC detection */
409 static void cpc925_mc_exit(struct mem_ctl_info *mci)
410 {
411 	/*
412 	 * WARNING:
413 	 * We are supposed to clear the ECC error detection bits,
414 	 * and it will be no problem to do so. However, once they
415 	 * are cleared here if we want to re-install CPC925 EDAC
416 	 * module later, setting them up in cpc925_mc_init() will
417 	 * trigger machine check exception.
418 	 * Also, it's ok to leave ECC error detection bits enabled,
419 	 * since they are reset to 1 by default or by boot loader.
420 	 */
421 
422 	return;
423 }
424 
425 /*
426  * Revert DDR column/row/bank addresses into page frame number and
427  * offset in page.
428  *
429  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
430  * physical address(PA) bits to column address(CA) bits mappings are:
431  * CA	0   1   2   3   4   5   6   7   8   9   10
432  * PA	59  58  57  56  55  54  53  52  51  50  49
433  *
434  * physical address(PA) bits to bank address(BA) bits mappings are:
435  * BA	0   1
436  * PA	43  44
437  *
438  * physical address(PA) bits to row address(RA) bits mappings are:
439  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
440  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
441  */
442 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
443 		unsigned long *pfn, unsigned long *offset, int *csrow)
444 {
445 	u32 bcnt, rank, col, bank, row;
446 	u32 c;
447 	unsigned long pa;
448 	int i;
449 
450 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
451 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
452 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
453 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
454 	row = mear & MEAR_ROW_MASK;
455 
456 	*csrow = rank;
457 
458 #ifdef CONFIG_EDAC_DEBUG
459 	if (mci->csrows[rank].first_page == 0) {
460 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
461 			"non-populated csrow, broken hardware?\n");
462 		return;
463 	}
464 #endif
465 
466 	/* Revert csrow number */
467 	pa = mci->csrows[rank].first_page << PAGE_SHIFT;
468 
469 	/* Revert column address */
470 	col += bcnt;
471 	for (i = 0; i < 11; i++) {
472 		c = col & 0x1;
473 		col >>= 1;
474 		pa |= c << (14 - i);
475 	}
476 
477 	/* Revert bank address */
478 	pa |= bank << 19;
479 
480 	/* Revert row address, in 4 steps */
481 	for (i = 0; i < 3; i++) {
482 		c = row & 0x1;
483 		row >>= 1;
484 		pa |= c << (26 - i);
485 	}
486 
487 	for (i = 0; i < 3; i++) {
488 		c = row & 0x1;
489 		row >>= 1;
490 		pa |= c << (21 + i);
491 	}
492 
493 	for (i = 0; i < 4; i++) {
494 		c = row & 0x1;
495 		row >>= 1;
496 		pa |= c << (18 - i);
497 	}
498 
499 	for (i = 0; i < 3; i++) {
500 		c = row & 0x1;
501 		row >>= 1;
502 		pa |= c << (29 - i);
503 	}
504 
505 	*offset = pa & (PAGE_SIZE - 1);
506 	*pfn = pa >> PAGE_SHIFT;
507 
508 	debugf0("%s: ECC physical address 0x%lx\n", __func__, pa);
509 }
510 
511 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
512 {
513 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
514 		return 0;
515 
516 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
517 		return 1;
518 
519 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
520 			 syndrome);
521 	return 1;
522 }
523 
524 /* Check memory controller registers for ECC errors */
525 static void cpc925_mc_check(struct mem_ctl_info *mci)
526 {
527 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
528 	u32 apiexcp;
529 	u32 mear;
530 	u32 mesr;
531 	u16 syndrome;
532 	unsigned long pfn = 0, offset = 0;
533 	int csrow = 0, channel = 0;
534 
535 	/* APIEXCP is cleared when read */
536 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
537 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
538 		return;
539 
540 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
541 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
542 
543 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
544 
545 	/* Revert column/row addresses into page frame number, etc */
546 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
547 
548 	if (apiexcp & CECC_EXCP_DETECTED) {
549 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
550 		channel = cpc925_mc_find_channel(mci, syndrome);
551 		edac_mc_handle_ce(mci, pfn, offset, syndrome,
552 				  csrow, channel, mci->ctl_name);
553 	}
554 
555 	if (apiexcp & UECC_EXCP_DETECTED) {
556 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
557 		edac_mc_handle_ue(mci, pfn, offset, csrow, mci->ctl_name);
558 	}
559 
560 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
561 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
562 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
563 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
564 		apiexcp);
565 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
566 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
567 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
568 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
569 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
570 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
571 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
572 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
573 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
574 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
575 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
576 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
577 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
578 		mesr);
579 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
580 		syndrome);
581 }
582 
583 /******************** CPU err device********************************/
584 /* Enable CPU Errors detection */
585 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
586 {
587 	u32 apimask;
588 
589 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
590 	if ((apimask & CPU_MASK_ENABLE) == 0) {
591 		apimask |= CPU_MASK_ENABLE;
592 		__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
593 	}
594 }
595 
596 /* Disable CPU Errors detection */
597 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
598 {
599 	/*
600 	 * WARNING:
601 	 * We are supposed to clear the CPU error detection bits,
602 	 * and it will be no problem to do so. However, once they
603 	 * are cleared here if we want to re-install CPC925 EDAC
604 	 * module later, setting them up in cpc925_cpu_init() will
605 	 * trigger machine check exception.
606 	 * Also, it's ok to leave CPU error detection bits enabled,
607 	 * since they are reset to 1 by default.
608 	 */
609 
610 	return;
611 }
612 
613 /* Check for CPU Errors */
614 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
615 {
616 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
617 	u32 apiexcp;
618 	u32 apimask;
619 
620 	/* APIEXCP is cleared when read */
621 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
622 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
623 		return;
624 
625 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
626 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
627 				 "Processor Interface register dump:\n");
628 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
629 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
630 
631 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
632 }
633 
634 /******************** HT Link err device****************************/
635 /* Enable HyperTransport Link Error detection */
636 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
637 {
638 	u32 ht_errctrl;
639 
640 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
641 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
642 		ht_errctrl |= HT_ERRCTRL_ENABLE;
643 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
644 	}
645 }
646 
647 /* Disable HyperTransport Link Error detection */
648 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
649 {
650 	u32 ht_errctrl;
651 
652 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
653 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
654 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
655 }
656 
657 /* Check for HyperTransport Link errors */
658 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
659 {
660 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
661 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
662 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
663 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
664 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
665 
666 	if (!((brgctrl & BRGCTRL_DETSERR) ||
667 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
668 	      (errctrl & HT_ERRCTRL_DETECTED) ||
669 	      (linkerr & HT_LINKERR_DETECTED)))
670 		return;
671 
672 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
673 				 "HT register dump:\n");
674 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
675 		      brgctrl);
676 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
677 		      linkctrl);
678 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
679 		      errctrl);
680 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
681 		      linkerr);
682 
683 	/* Clear by write 1 */
684 	if (brgctrl & BRGCTRL_DETSERR)
685 		__raw_writel(BRGCTRL_DETSERR,
686 				dev_info->vbase + REG_BRGCTRL_OFFSET);
687 
688 	if (linkctrl & HT_LINKCTRL_DETECTED)
689 		__raw_writel(HT_LINKCTRL_DETECTED,
690 				dev_info->vbase + REG_LINKCTRL_OFFSET);
691 
692 	/* Initiate Secondary Bus Reset to clear the chain failure */
693 	if (errctrl & ERRCTRL_CHN_FAL)
694 		__raw_writel(BRGCTRL_SECBUSRESET,
695 				dev_info->vbase + REG_BRGCTRL_OFFSET);
696 
697 	if (errctrl & ERRCTRL_RSP_ERR)
698 		__raw_writel(ERRCTRL_RSP_ERR,
699 				dev_info->vbase + REG_ERRCTRL_OFFSET);
700 
701 	if (linkerr & HT_LINKERR_DETECTED)
702 		__raw_writel(HT_LINKERR_DETECTED,
703 				dev_info->vbase + REG_LINKERR_OFFSET);
704 
705 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
706 }
707 
708 static struct cpc925_dev_info cpc925_devs[] = {
709 	{
710 	.ctl_name = CPC925_CPU_ERR_DEV,
711 	.init = cpc925_cpu_init,
712 	.exit = cpc925_cpu_exit,
713 	.check = cpc925_cpu_check,
714 	},
715 	{
716 	.ctl_name = CPC925_HT_LINK_DEV,
717 	.init = cpc925_htlink_init,
718 	.exit = cpc925_htlink_exit,
719 	.check = cpc925_htlink_check,
720 	},
721 	{0}, /* Terminated by NULL */
722 };
723 
724 /*
725  * Add CPU Err detection and HyperTransport Link Err detection
726  * as common "edac_device", they have no corresponding device
727  * nodes in the Open Firmware DTB and we have to add platform
728  * devices for them. Also, they will share the MMIO with that
729  * of memory controller.
730  */
731 static void cpc925_add_edac_devices(void __iomem *vbase)
732 {
733 	struct cpc925_dev_info *dev_info;
734 
735 	if (!vbase) {
736 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
737 		return;
738 	}
739 
740 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
741 		dev_info->vbase = vbase;
742 		dev_info->pdev = platform_device_register_simple(
743 					dev_info->ctl_name, 0, NULL, 0);
744 		if (IS_ERR(dev_info->pdev)) {
745 			cpc925_printk(KERN_ERR,
746 				"Can't register platform device for %s\n",
747 				dev_info->ctl_name);
748 			continue;
749 		}
750 
751 		/*
752 		 * Don't have to allocate private structure but
753 		 * make use of cpc925_devs[] instead.
754 		 */
755 		dev_info->edac_idx = edac_device_alloc_index();
756 		dev_info->edac_dev =
757 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
758 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
759 		if (!dev_info->edac_dev) {
760 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
761 			goto err1;
762 		}
763 
764 		dev_info->edac_dev->pvt_info = dev_info;
765 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
766 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
767 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
768 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
769 
770 		if (edac_op_state == EDAC_OPSTATE_POLL)
771 			dev_info->edac_dev->edac_check = dev_info->check;
772 
773 		if (dev_info->init)
774 			dev_info->init(dev_info);
775 
776 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
777 			cpc925_printk(KERN_ERR,
778 				"Unable to add edac device for %s\n",
779 				dev_info->ctl_name);
780 			goto err2;
781 		}
782 
783 		debugf0("%s: Successfully added edac device for %s\n",
784 			__func__, dev_info->ctl_name);
785 
786 		continue;
787 
788 err2:
789 		if (dev_info->exit)
790 			dev_info->exit(dev_info);
791 		edac_device_free_ctl_info(dev_info->edac_dev);
792 err1:
793 		platform_device_unregister(dev_info->pdev);
794 	}
795 }
796 
797 /*
798  * Delete the common "edac_device" for CPU Err Detection
799  * and HyperTransport Link Err Detection
800  */
801 static void cpc925_del_edac_devices(void)
802 {
803 	struct cpc925_dev_info *dev_info;
804 
805 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
806 		if (dev_info->edac_dev) {
807 			edac_device_del_device(dev_info->edac_dev->dev);
808 			edac_device_free_ctl_info(dev_info->edac_dev);
809 			platform_device_unregister(dev_info->pdev);
810 		}
811 
812 		if (dev_info->exit)
813 			dev_info->exit(dev_info);
814 
815 		debugf0("%s: Successfully deleted edac device for %s\n",
816 			__func__, dev_info->ctl_name);
817 	}
818 }
819 
820 /* Convert current back-ground scrub rate into byte/sec bandwith */
821 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
822 {
823 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
824 	int bw;
825 	u32 mscr;
826 	u8 si;
827 
828 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
829 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
830 
831 	debugf0("%s, Mem Scrub Ctrl Register 0x%x\n", __func__, mscr);
832 
833 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
834 	    (si == 0)) {
835 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
836 		bw = 0;
837 	} else
838 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
839 
840 	return bw;
841 }
842 
843 /* Return 0 for single channel; 1 for dual channel */
844 static int cpc925_mc_get_channels(void __iomem *vbase)
845 {
846 	int dual = 0;
847 	u32 mbcr;
848 
849 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
850 
851 	/*
852 	 * Dual channel only when 128-bit wide physical bus
853 	 * and 128-bit configuration.
854 	 */
855 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
856 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
857 		dual = 1;
858 
859 	debugf0("%s: %s channel\n", __func__,
860 		(dual > 0) ? "Dual" : "Single");
861 
862 	return dual;
863 }
864 
865 static int __devinit cpc925_probe(struct platform_device *pdev)
866 {
867 	static int edac_mc_idx;
868 	struct mem_ctl_info *mci;
869 	void __iomem *vbase;
870 	struct cpc925_mc_pdata *pdata;
871 	struct resource *r;
872 	int res = 0, nr_channels;
873 
874 	debugf0("%s: %s platform device found!\n", __func__, pdev->name);
875 
876 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
877 		res = -ENOMEM;
878 		goto out;
879 	}
880 
881 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
882 	if (!r) {
883 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
884 		res = -ENOENT;
885 		goto err1;
886 	}
887 
888 	if (!devm_request_mem_region(&pdev->dev,
889 				     r->start,
890 				     resource_size(r),
891 				     pdev->name)) {
892 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
893 		res = -EBUSY;
894 		goto err1;
895 	}
896 
897 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
898 	if (!vbase) {
899 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
900 		res = -ENOMEM;
901 		goto err2;
902 	}
903 
904 	nr_channels = cpc925_mc_get_channels(vbase);
905 	mci = edac_mc_alloc(sizeof(struct cpc925_mc_pdata),
906 			CPC925_NR_CSROWS, nr_channels + 1, edac_mc_idx);
907 	if (!mci) {
908 		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
909 		res = -ENOMEM;
910 		goto err2;
911 	}
912 
913 	pdata = mci->pvt_info;
914 	pdata->vbase = vbase;
915 	pdata->edac_idx = edac_mc_idx++;
916 	pdata->name = pdev->name;
917 
918 	mci->dev = &pdev->dev;
919 	platform_set_drvdata(pdev, mci);
920 	mci->dev_name = dev_name(&pdev->dev);
921 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
922 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
923 	mci->edac_cap = EDAC_FLAG_SECDED;
924 	mci->mod_name = CPC925_EDAC_MOD_STR;
925 	mci->mod_ver = CPC925_EDAC_REVISION;
926 	mci->ctl_name = pdev->name;
927 
928 	if (edac_op_state == EDAC_OPSTATE_POLL)
929 		mci->edac_check = cpc925_mc_check;
930 
931 	mci->ctl_page_to_phys = NULL;
932 	mci->scrub_mode = SCRUB_SW_SRC;
933 	mci->set_sdram_scrub_rate = NULL;
934 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
935 
936 	cpc925_init_csrows(mci);
937 
938 	/* Setup memory controller registers */
939 	cpc925_mc_init(mci);
940 
941 	if (edac_mc_add_mc(mci) > 0) {
942 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
943 		goto err3;
944 	}
945 
946 	cpc925_add_edac_devices(vbase);
947 
948 	/* get this far and it's successful */
949 	debugf0("%s: success\n", __func__);
950 
951 	res = 0;
952 	goto out;
953 
954 err3:
955 	cpc925_mc_exit(mci);
956 	edac_mc_free(mci);
957 err2:
958 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
959 err1:
960 	devres_release_group(&pdev->dev, cpc925_probe);
961 out:
962 	return res;
963 }
964 
965 static int cpc925_remove(struct platform_device *pdev)
966 {
967 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
968 
969 	/*
970 	 * Delete common edac devices before edac mc, because
971 	 * the former share the MMIO of the latter.
972 	 */
973 	cpc925_del_edac_devices();
974 	cpc925_mc_exit(mci);
975 
976 	edac_mc_del_mc(&pdev->dev);
977 	edac_mc_free(mci);
978 
979 	return 0;
980 }
981 
982 static struct platform_driver cpc925_edac_driver = {
983 	.probe = cpc925_probe,
984 	.remove = cpc925_remove,
985 	.driver = {
986 		   .name = "cpc925_edac",
987 	}
988 };
989 
990 static int __init cpc925_edac_init(void)
991 {
992 	int ret = 0;
993 
994 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
995 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
996 
997 	/* Only support POLL mode so far */
998 	edac_op_state = EDAC_OPSTATE_POLL;
999 
1000 	ret = platform_driver_register(&cpc925_edac_driver);
1001 	if (ret) {
1002 		printk(KERN_WARNING "Failed to register %s\n",
1003 			CPC925_EDAC_MOD_STR);
1004 	}
1005 
1006 	return ret;
1007 }
1008 
1009 static void __exit cpc925_edac_exit(void)
1010 {
1011 	platform_driver_unregister(&cpc925_edac_driver);
1012 }
1013 
1014 module_init(cpc925_edac_init);
1015 module_exit(cpc925_edac_exit);
1016 
1017 MODULE_LICENSE("GPL");
1018 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1019 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1020