xref: /openbmc/linux/drivers/edac/cpc925_edac.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * cpc925_edac.c, EDAC driver for IBM CPC925 Bridge and Memory Controller.
4  *
5  * Copyright (c) 2008 Wind River Systems, Inc.
6  *
7  * Authors:	Cao Qingtao <qingtao.cao@windriver.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/edac.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/gfp.h>
17 
18 #include "edac_module.h"
19 
20 #define CPC925_EDAC_REVISION	" Ver: 1.0.0"
21 #define CPC925_EDAC_MOD_STR	"cpc925_edac"
22 
23 #define cpc925_printk(level, fmt, arg...) \
24 	edac_printk(level, "CPC925", fmt, ##arg)
25 
26 #define cpc925_mc_printk(mci, level, fmt, arg...) \
27 	edac_mc_chipset_printk(mci, level, "CPC925", fmt, ##arg)
28 
29 /*
30  * CPC925 registers are of 32 bits with bit0 defined at the
31  * most significant bit and bit31 at that of least significant.
32  */
33 #define CPC925_BITS_PER_REG	32
34 #define CPC925_BIT(nr)		(1UL << (CPC925_BITS_PER_REG - 1 - nr))
35 
36 /*
37  * EDAC device names for the error detections of
38  * CPU Interface and Hypertransport Link.
39  */
40 #define CPC925_CPU_ERR_DEV	"cpu"
41 #define CPC925_HT_LINK_DEV	"htlink"
42 
43 /* Suppose DDR Refresh cycle is 15.6 microsecond */
44 #define CPC925_REF_FREQ		0xFA69
45 #define CPC925_SCRUB_BLOCK_SIZE 64	/* bytes */
46 #define CPC925_NR_CSROWS	8
47 
48 /*
49  * All registers and bits definitions are taken from
50  * "CPC925 Bridge and Memory Controller User Manual, SA14-2761-02".
51  */
52 
53 /*
54  * CPU and Memory Controller Registers
55  */
56 /************************************************************
57  *	Processor Interface Exception Mask Register (APIMASK)
58  ************************************************************/
59 #define REG_APIMASK_OFFSET	0x30070
60 enum apimask_bits {
61 	APIMASK_DART	= CPC925_BIT(0), /* DART Exception */
62 	APIMASK_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
63 	APIMASK_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
64 	APIMASK_STAT	= CPC925_BIT(3), /* Status Exception */
65 	APIMASK_DERR	= CPC925_BIT(4), /* Data Error Exception */
66 	APIMASK_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
67 	APIMASK_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
68 					 /* BIT(7) Reserved */
69 	APIMASK_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
70 	APIMASK_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
71 	APIMASK_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
72 	APIMASK_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
73 
74 	CPU_MASK_ENABLE = (APIMASK_DART | APIMASK_ADI0 | APIMASK_ADI1 |
75 			   APIMASK_STAT | APIMASK_DERR | APIMASK_ADRS0 |
76 			   APIMASK_ADRS1),
77 	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
78 			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
79 };
80 #define APIMASK_ADI(n)		CPC925_BIT(((n)+1))
81 
82 /************************************************************
83  *	Processor Interface Exception Register (APIEXCP)
84  ************************************************************/
85 #define REG_APIEXCP_OFFSET	0x30060
86 enum apiexcp_bits {
87 	APIEXCP_DART	= CPC925_BIT(0), /* DART Exception */
88 	APIEXCP_ADI0	= CPC925_BIT(1), /* Handshake Error on PI0_ADI */
89 	APIEXCP_ADI1	= CPC925_BIT(2), /* Handshake Error on PI1_ADI */
90 	APIEXCP_STAT	= CPC925_BIT(3), /* Status Exception */
91 	APIEXCP_DERR	= CPC925_BIT(4), /* Data Error Exception */
92 	APIEXCP_ADRS0	= CPC925_BIT(5), /* Addressing Exception on PI0 */
93 	APIEXCP_ADRS1	= CPC925_BIT(6), /* Addressing Exception on PI1 */
94 					 /* BIT(7) Reserved */
95 	APIEXCP_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
96 	APIEXCP_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
97 	APIEXCP_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
98 	APIEXCP_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
99 
100 	CPU_EXCP_DETECTED = (APIEXCP_DART | APIEXCP_ADI0 | APIEXCP_ADI1 |
101 			     APIEXCP_STAT | APIEXCP_DERR | APIEXCP_ADRS0 |
102 			     APIEXCP_ADRS1),
103 	UECC_EXCP_DETECTED = (APIEXCP_ECC_UE_H | APIEXCP_ECC_UE_L),
104 	CECC_EXCP_DETECTED = (APIEXCP_ECC_CE_H | APIEXCP_ECC_CE_L),
105 	ECC_EXCP_DETECTED = (UECC_EXCP_DETECTED | CECC_EXCP_DETECTED),
106 };
107 
108 /************************************************************
109  *	Memory Bus Configuration Register (MBCR)
110 ************************************************************/
111 #define REG_MBCR_OFFSET		0x2190
112 #define MBCR_64BITCFG_SHIFT	23
113 #define MBCR_64BITCFG_MASK	(1UL << MBCR_64BITCFG_SHIFT)
114 #define MBCR_64BITBUS_SHIFT	22
115 #define MBCR_64BITBUS_MASK	(1UL << MBCR_64BITBUS_SHIFT)
116 
117 /************************************************************
118  *	Memory Bank Mode Register (MBMR)
119 ************************************************************/
120 #define REG_MBMR_OFFSET		0x21C0
121 #define MBMR_MODE_MAX_VALUE	0xF
122 #define MBMR_MODE_SHIFT		25
123 #define MBMR_MODE_MASK		(MBMR_MODE_MAX_VALUE << MBMR_MODE_SHIFT)
124 #define MBMR_BBA_SHIFT		24
125 #define MBMR_BBA_MASK		(1UL << MBMR_BBA_SHIFT)
126 
127 /************************************************************
128  *	Memory Bank Boundary Address Register (MBBAR)
129  ************************************************************/
130 #define REG_MBBAR_OFFSET	0x21D0
131 #define MBBAR_BBA_MAX_VALUE	0xFF
132 #define MBBAR_BBA_SHIFT		24
133 #define MBBAR_BBA_MASK		(MBBAR_BBA_MAX_VALUE << MBBAR_BBA_SHIFT)
134 
135 /************************************************************
136  *	Memory Scrub Control Register (MSCR)
137  ************************************************************/
138 #define REG_MSCR_OFFSET		0x2400
139 #define MSCR_SCRUB_MOD_MASK	0xC0000000 /* scrub_mod - bit0:1*/
140 #define MSCR_BACKGR_SCRUB	0x40000000 /* 01 */
141 #define MSCR_SI_SHIFT		16 	/* si - bit8:15*/
142 #define MSCR_SI_MAX_VALUE	0xFF
143 #define MSCR_SI_MASK		(MSCR_SI_MAX_VALUE << MSCR_SI_SHIFT)
144 
145 /************************************************************
146  *	Memory Scrub Range Start Register (MSRSR)
147  ************************************************************/
148 #define REG_MSRSR_OFFSET	0x2410
149 
150 /************************************************************
151  *	Memory Scrub Range End Register (MSRER)
152  ************************************************************/
153 #define REG_MSRER_OFFSET	0x2420
154 
155 /************************************************************
156  *	Memory Scrub Pattern Register (MSPR)
157  ************************************************************/
158 #define REG_MSPR_OFFSET		0x2430
159 
160 /************************************************************
161  *	Memory Check Control Register (MCCR)
162  ************************************************************/
163 #define REG_MCCR_OFFSET		0x2440
164 enum mccr_bits {
165 	MCCR_ECC_EN	= CPC925_BIT(0), /* ECC high and low check */
166 };
167 
168 /************************************************************
169  *	Memory Check Range End Register (MCRER)
170  ************************************************************/
171 #define REG_MCRER_OFFSET	0x2450
172 
173 /************************************************************
174  *	Memory Error Address Register (MEAR)
175  ************************************************************/
176 #define REG_MEAR_OFFSET		0x2460
177 #define MEAR_BCNT_MAX_VALUE	0x3
178 #define MEAR_BCNT_SHIFT		30
179 #define MEAR_BCNT_MASK		(MEAR_BCNT_MAX_VALUE << MEAR_BCNT_SHIFT)
180 #define MEAR_RANK_MAX_VALUE	0x7
181 #define MEAR_RANK_SHIFT		27
182 #define MEAR_RANK_MASK		(MEAR_RANK_MAX_VALUE << MEAR_RANK_SHIFT)
183 #define MEAR_COL_MAX_VALUE	0x7FF
184 #define MEAR_COL_SHIFT		16
185 #define MEAR_COL_MASK		(MEAR_COL_MAX_VALUE << MEAR_COL_SHIFT)
186 #define MEAR_BANK_MAX_VALUE	0x3
187 #define MEAR_BANK_SHIFT		14
188 #define MEAR_BANK_MASK		(MEAR_BANK_MAX_VALUE << MEAR_BANK_SHIFT)
189 #define MEAR_ROW_MASK		0x00003FFF
190 
191 /************************************************************
192  *	Memory Error Syndrome Register (MESR)
193  ************************************************************/
194 #define REG_MESR_OFFSET		0x2470
195 #define MESR_ECC_SYN_H_MASK	0xFF00
196 #define MESR_ECC_SYN_L_MASK	0x00FF
197 
198 /************************************************************
199  *	Memory Mode Control Register (MMCR)
200  ************************************************************/
201 #define REG_MMCR_OFFSET		0x2500
202 enum mmcr_bits {
203 	MMCR_REG_DIMM_MODE = CPC925_BIT(3),
204 };
205 
206 /*
207  * HyperTransport Link Registers
208  */
209 /************************************************************
210  *  Error Handling/Enumeration Scratch Pad Register (ERRCTRL)
211  ************************************************************/
212 #define REG_ERRCTRL_OFFSET	0x70140
213 enum errctrl_bits {			 /* nonfatal interrupts for */
214 	ERRCTRL_SERR_NF	= CPC925_BIT(0), /* system error */
215 	ERRCTRL_CRC_NF	= CPC925_BIT(1), /* CRC error */
216 	ERRCTRL_RSP_NF	= CPC925_BIT(2), /* Response error */
217 	ERRCTRL_EOC_NF	= CPC925_BIT(3), /* End-Of-Chain error */
218 	ERRCTRL_OVF_NF	= CPC925_BIT(4), /* Overflow error */
219 	ERRCTRL_PROT_NF	= CPC925_BIT(5), /* Protocol error */
220 
221 	ERRCTRL_RSP_ERR	= CPC925_BIT(6), /* Response error received */
222 	ERRCTRL_CHN_FAL = CPC925_BIT(7), /* Sync flooding detected */
223 
224 	HT_ERRCTRL_ENABLE = (ERRCTRL_SERR_NF | ERRCTRL_CRC_NF |
225 			     ERRCTRL_RSP_NF | ERRCTRL_EOC_NF |
226 			     ERRCTRL_OVF_NF | ERRCTRL_PROT_NF),
227 	HT_ERRCTRL_DETECTED = (ERRCTRL_RSP_ERR | ERRCTRL_CHN_FAL),
228 };
229 
230 /************************************************************
231  *  Link Configuration and Link Control Register (LINKCTRL)
232  ************************************************************/
233 #define REG_LINKCTRL_OFFSET	0x70110
234 enum linkctrl_bits {
235 	LINKCTRL_CRC_ERR	= (CPC925_BIT(22) | CPC925_BIT(23)),
236 	LINKCTRL_LINK_FAIL	= CPC925_BIT(27),
237 
238 	HT_LINKCTRL_DETECTED	= (LINKCTRL_CRC_ERR | LINKCTRL_LINK_FAIL),
239 };
240 
241 /************************************************************
242  *  Link FreqCap/Error/Freq/Revision ID Register (LINKERR)
243  ************************************************************/
244 #define REG_LINKERR_OFFSET	0x70120
245 enum linkerr_bits {
246 	LINKERR_EOC_ERR		= CPC925_BIT(17), /* End-Of-Chain error */
247 	LINKERR_OVF_ERR		= CPC925_BIT(18), /* Receive Buffer Overflow */
248 	LINKERR_PROT_ERR	= CPC925_BIT(19), /* Protocol error */
249 
250 	HT_LINKERR_DETECTED	= (LINKERR_EOC_ERR | LINKERR_OVF_ERR |
251 				   LINKERR_PROT_ERR),
252 };
253 
254 /************************************************************
255  *	Bridge Control Register (BRGCTRL)
256  ************************************************************/
257 #define REG_BRGCTRL_OFFSET	0x70300
258 enum brgctrl_bits {
259 	BRGCTRL_DETSERR = CPC925_BIT(0), /* SERR on Secondary Bus */
260 	BRGCTRL_SECBUSRESET = CPC925_BIT(9), /* Secondary Bus Reset */
261 };
262 
263 /* Private structure for edac memory controller */
264 struct cpc925_mc_pdata {
265 	void __iomem *vbase;
266 	unsigned long total_mem;
267 	const char *name;
268 	int edac_idx;
269 };
270 
271 /* Private structure for common edac device */
272 struct cpc925_dev_info {
273 	void __iomem *vbase;
274 	struct platform_device *pdev;
275 	char *ctl_name;
276 	int edac_idx;
277 	struct edac_device_ctl_info *edac_dev;
278 	void (*init)(struct cpc925_dev_info *dev_info);
279 	void (*exit)(struct cpc925_dev_info *dev_info);
280 	void (*check)(struct edac_device_ctl_info *edac_dev);
281 };
282 
283 /* Get total memory size from Open Firmware DTB */
284 static void get_total_mem(struct cpc925_mc_pdata *pdata)
285 {
286 	struct device_node *np = NULL;
287 	const unsigned int *reg, *reg_end;
288 	int len, sw, aw;
289 	unsigned long start, size;
290 
291 	np = of_find_node_by_type(NULL, "memory");
292 	if (!np)
293 		return;
294 
295 	aw = of_n_addr_cells(np);
296 	sw = of_n_size_cells(np);
297 	reg = (const unsigned int *)of_get_property(np, "reg", &len);
298 	reg_end = reg + len/4;
299 
300 	pdata->total_mem = 0;
301 	do {
302 		start = of_read_number(reg, aw);
303 		reg += aw;
304 		size = of_read_number(reg, sw);
305 		reg += sw;
306 		edac_dbg(1, "start 0x%lx, size 0x%lx\n", start, size);
307 		pdata->total_mem += size;
308 	} while (reg < reg_end);
309 
310 	of_node_put(np);
311 	edac_dbg(0, "total_mem 0x%lx\n", pdata->total_mem);
312 }
313 
314 static void cpc925_init_csrows(struct mem_ctl_info *mci)
315 {
316 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
317 	struct csrow_info *csrow;
318 	struct dimm_info *dimm;
319 	enum dev_type dtype;
320 	int index, j;
321 	u32 mbmr, mbbar, bba, grain;
322 	unsigned long row_size, nr_pages, last_nr_pages = 0;
323 
324 	get_total_mem(pdata);
325 
326 	for (index = 0; index < mci->nr_csrows; index++) {
327 		mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
328 				   0x20 * index);
329 		mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
330 				   0x20 + index);
331 		bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
332 		       ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);
333 
334 		if (bba == 0)
335 			continue; /* not populated */
336 
337 		csrow = mci->csrows[index];
338 
339 		row_size = bba * (1UL << 28);	/* 256M */
340 		csrow->first_page = last_nr_pages;
341 		nr_pages = row_size >> PAGE_SHIFT;
342 		csrow->last_page = csrow->first_page + nr_pages - 1;
343 		last_nr_pages = csrow->last_page + 1;
344 
345 		switch (csrow->nr_channels) {
346 		case 1: /* Single channel */
347 			grain = 32; /* four-beat burst of 32 bytes */
348 			break;
349 		case 2: /* Dual channel */
350 		default:
351 			grain = 64; /* four-beat burst of 64 bytes */
352 			break;
353 		}
354 		switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
355 		case 6: /* 0110, no way to differentiate X8 VS X16 */
356 		case 5:	/* 0101 */
357 		case 8: /* 1000 */
358 			dtype = DEV_X16;
359 			break;
360 		case 7: /* 0111 */
361 		case 9: /* 1001 */
362 			dtype = DEV_X8;
363 			break;
364 		default:
365 			dtype = DEV_UNKNOWN;
366 		break;
367 		}
368 		for (j = 0; j < csrow->nr_channels; j++) {
369 			dimm = csrow->channels[j]->dimm;
370 			dimm->nr_pages = nr_pages / csrow->nr_channels;
371 			dimm->mtype = MEM_RDDR;
372 			dimm->edac_mode = EDAC_SECDED;
373 			dimm->grain = grain;
374 			dimm->dtype = dtype;
375 		}
376 	}
377 }
378 
379 /* Enable memory controller ECC detection */
380 static void cpc925_mc_init(struct mem_ctl_info *mci)
381 {
382 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
383 	u32 apimask;
384 	u32 mccr;
385 
386 	/* Enable various ECC error exceptions */
387 	apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
388 	if ((apimask & ECC_MASK_ENABLE) == 0) {
389 		apimask |= ECC_MASK_ENABLE;
390 		__raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
391 	}
392 
393 	/* Enable ECC detection */
394 	mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
395 	if ((mccr & MCCR_ECC_EN) == 0) {
396 		mccr |= MCCR_ECC_EN;
397 		__raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
398 	}
399 }
400 
401 /* Disable memory controller ECC detection */
402 static void cpc925_mc_exit(struct mem_ctl_info *mci)
403 {
404 	/*
405 	 * WARNING:
406 	 * We are supposed to clear the ECC error detection bits,
407 	 * and it will be no problem to do so. However, once they
408 	 * are cleared here if we want to re-install CPC925 EDAC
409 	 * module later, setting them up in cpc925_mc_init() will
410 	 * trigger machine check exception.
411 	 * Also, it's ok to leave ECC error detection bits enabled,
412 	 * since they are reset to 1 by default or by boot loader.
413 	 */
414 
415 	return;
416 }
417 
418 /*
419  * Revert DDR column/row/bank addresses into page frame number and
420  * offset in page.
421  *
422  * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
423  * physical address(PA) bits to column address(CA) bits mappings are:
424  * CA	0   1   2   3   4   5   6   7   8   9   10
425  * PA	59  58  57  56  55  54  53  52  51  50  49
426  *
427  * physical address(PA) bits to bank address(BA) bits mappings are:
428  * BA	0   1
429  * PA	43  44
430  *
431  * physical address(PA) bits to row address(RA) bits mappings are:
432  * RA	0   1   2   3   4   5   6   7   8   9   10   11   12
433  * PA	36  35  34  48  47  46  45  40  41  42  39   38   37
434  */
435 static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
436 		unsigned long *pfn, unsigned long *offset, int *csrow)
437 {
438 	u32 bcnt, rank, col, bank, row;
439 	u32 c;
440 	unsigned long pa;
441 	int i;
442 
443 	bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
444 	rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
445 	col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
446 	bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
447 	row = mear & MEAR_ROW_MASK;
448 
449 	*csrow = rank;
450 
451 #ifdef CONFIG_EDAC_DEBUG
452 	if (mci->csrows[rank]->first_page == 0) {
453 		cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
454 			"non-populated csrow, broken hardware?\n");
455 		return;
456 	}
457 #endif
458 
459 	/* Revert csrow number */
460 	pa = mci->csrows[rank]->first_page << PAGE_SHIFT;
461 
462 	/* Revert column address */
463 	col += bcnt;
464 	for (i = 0; i < 11; i++) {
465 		c = col & 0x1;
466 		col >>= 1;
467 		pa |= c << (14 - i);
468 	}
469 
470 	/* Revert bank address */
471 	pa |= bank << 19;
472 
473 	/* Revert row address, in 4 steps */
474 	for (i = 0; i < 3; i++) {
475 		c = row & 0x1;
476 		row >>= 1;
477 		pa |= c << (26 - i);
478 	}
479 
480 	for (i = 0; i < 3; i++) {
481 		c = row & 0x1;
482 		row >>= 1;
483 		pa |= c << (21 + i);
484 	}
485 
486 	for (i = 0; i < 4; i++) {
487 		c = row & 0x1;
488 		row >>= 1;
489 		pa |= c << (18 - i);
490 	}
491 
492 	for (i = 0; i < 3; i++) {
493 		c = row & 0x1;
494 		row >>= 1;
495 		pa |= c << (29 - i);
496 	}
497 
498 	*offset = pa & (PAGE_SIZE - 1);
499 	*pfn = pa >> PAGE_SHIFT;
500 
501 	edac_dbg(0, "ECC physical address 0x%lx\n", pa);
502 }
503 
504 static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
505 {
506 	if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
507 		return 0;
508 
509 	if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
510 		return 1;
511 
512 	cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
513 			 syndrome);
514 	return 1;
515 }
516 
517 /* Check memory controller registers for ECC errors */
518 static void cpc925_mc_check(struct mem_ctl_info *mci)
519 {
520 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
521 	u32 apiexcp;
522 	u32 mear;
523 	u32 mesr;
524 	u16 syndrome;
525 	unsigned long pfn = 0, offset = 0;
526 	int csrow = 0, channel = 0;
527 
528 	/* APIEXCP is cleared when read */
529 	apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
530 	if ((apiexcp & ECC_EXCP_DETECTED) == 0)
531 		return;
532 
533 	mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
534 	syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
535 
536 	mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
537 
538 	/* Revert column/row addresses into page frame number, etc */
539 	cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
540 
541 	if (apiexcp & CECC_EXCP_DETECTED) {
542 		cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
543 		channel = cpc925_mc_find_channel(mci, syndrome);
544 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
545 				     pfn, offset, syndrome,
546 				     csrow, channel, -1,
547 				     mci->ctl_name, "");
548 	}
549 
550 	if (apiexcp & UECC_EXCP_DETECTED) {
551 		cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
552 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
553 				     pfn, offset, 0,
554 				     csrow, -1, -1,
555 				     mci->ctl_name, "");
556 	}
557 
558 	cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
559 	cpc925_mc_printk(mci, KERN_INFO, "APIMASK		0x%08x\n",
560 		__raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
561 	cpc925_mc_printk(mci, KERN_INFO, "APIEXCP		0x%08x\n",
562 		apiexcp);
563 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl	0x%08x\n",
564 		__raw_readl(pdata->vbase + REG_MSCR_OFFSET));
565 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start	0x%08x\n",
566 		__raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
567 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End	0x%08x\n",
568 		__raw_readl(pdata->vbase + REG_MSRER_OFFSET));
569 	cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern	0x%08x\n",
570 		__raw_readl(pdata->vbase + REG_MSPR_OFFSET));
571 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl		0x%08x\n",
572 		__raw_readl(pdata->vbase + REG_MCCR_OFFSET));
573 	cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End	0x%08x\n",
574 		__raw_readl(pdata->vbase + REG_MCRER_OFFSET));
575 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address	0x%08x\n",
576 		mesr);
577 	cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome	0x%08x\n",
578 		syndrome);
579 }
580 
581 /******************** CPU err device********************************/
582 static u32 cpc925_cpu_mask_disabled(void)
583 {
584 	struct device_node *cpunode;
585 	static u32 mask = 0;
586 
587 	/* use cached value if available */
588 	if (mask != 0)
589 		return mask;
590 
591 	mask = APIMASK_ADI0 | APIMASK_ADI1;
592 
593 	for_each_of_cpu_node(cpunode) {
594 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
595 		if (reg == NULL || *reg > 2) {
596 			cpc925_printk(KERN_ERR, "Bad reg value at %pOF\n", cpunode);
597 			continue;
598 		}
599 
600 		mask &= ~APIMASK_ADI(*reg);
601 	}
602 
603 	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
604 		/* We assume that each CPU sits on it's own PI and that
605 		 * for present CPUs the reg property equals to the PI
606 		 * interface id */
607 		cpc925_printk(KERN_WARNING,
608 				"Assuming PI id is equal to CPU MPIC id!\n");
609 	}
610 
611 	return mask;
612 }
613 
614 /* Enable CPU Errors detection */
615 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
616 {
617 	u32 apimask;
618 	u32 cpumask;
619 
620 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
621 
622 	cpumask = cpc925_cpu_mask_disabled();
623 	if (apimask & cpumask) {
624 		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
625 				"but enabled in APIMASK, disabling\n");
626 		apimask &= ~cpumask;
627 	}
628 
629 	if ((apimask & CPU_MASK_ENABLE) == 0)
630 		apimask |= CPU_MASK_ENABLE;
631 
632 	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
633 }
634 
635 /* Disable CPU Errors detection */
636 static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
637 {
638 	/*
639 	 * WARNING:
640 	 * We are supposed to clear the CPU error detection bits,
641 	 * and it will be no problem to do so. However, once they
642 	 * are cleared here if we want to re-install CPC925 EDAC
643 	 * module later, setting them up in cpc925_cpu_init() will
644 	 * trigger machine check exception.
645 	 * Also, it's ok to leave CPU error detection bits enabled,
646 	 * since they are reset to 1 by default.
647 	 */
648 
649 	return;
650 }
651 
652 /* Check for CPU Errors */
653 static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
654 {
655 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
656 	u32 apiexcp;
657 	u32 apimask;
658 
659 	/* APIEXCP is cleared when read */
660 	apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
661 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
662 		return;
663 
664 	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
665 		return;
666 
667 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
668 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
669 				 "Processor Interface register dump:\n");
670 	cpc925_printk(KERN_INFO, "APIMASK		0x%08x\n", apimask);
671 	cpc925_printk(KERN_INFO, "APIEXCP		0x%08x\n", apiexcp);
672 
673 	edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
674 }
675 
676 /******************** HT Link err device****************************/
677 /* Enable HyperTransport Link Error detection */
678 static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
679 {
680 	u32 ht_errctrl;
681 
682 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
683 	if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
684 		ht_errctrl |= HT_ERRCTRL_ENABLE;
685 		__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
686 	}
687 }
688 
689 /* Disable HyperTransport Link Error detection */
690 static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
691 {
692 	u32 ht_errctrl;
693 
694 	ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
695 	ht_errctrl &= ~HT_ERRCTRL_ENABLE;
696 	__raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
697 }
698 
699 /* Check for HyperTransport Link errors */
700 static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
701 {
702 	struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
703 	u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
704 	u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
705 	u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
706 	u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
707 
708 	if (!((brgctrl & BRGCTRL_DETSERR) ||
709 	      (linkctrl & HT_LINKCTRL_DETECTED) ||
710 	      (errctrl & HT_ERRCTRL_DETECTED) ||
711 	      (linkerr & HT_LINKERR_DETECTED)))
712 		return;
713 
714 	cpc925_printk(KERN_INFO, "HT Link Fault\n"
715 				 "HT register dump:\n");
716 	cpc925_printk(KERN_INFO, "Bridge Ctrl			0x%08x\n",
717 		      brgctrl);
718 	cpc925_printk(KERN_INFO, "Link Config Ctrl		0x%08x\n",
719 		      linkctrl);
720 	cpc925_printk(KERN_INFO, "Error Enum and Ctrl		0x%08x\n",
721 		      errctrl);
722 	cpc925_printk(KERN_INFO, "Link Error			0x%08x\n",
723 		      linkerr);
724 
725 	/* Clear by write 1 */
726 	if (brgctrl & BRGCTRL_DETSERR)
727 		__raw_writel(BRGCTRL_DETSERR,
728 				dev_info->vbase + REG_BRGCTRL_OFFSET);
729 
730 	if (linkctrl & HT_LINKCTRL_DETECTED)
731 		__raw_writel(HT_LINKCTRL_DETECTED,
732 				dev_info->vbase + REG_LINKCTRL_OFFSET);
733 
734 	/* Initiate Secondary Bus Reset to clear the chain failure */
735 	if (errctrl & ERRCTRL_CHN_FAL)
736 		__raw_writel(BRGCTRL_SECBUSRESET,
737 				dev_info->vbase + REG_BRGCTRL_OFFSET);
738 
739 	if (errctrl & ERRCTRL_RSP_ERR)
740 		__raw_writel(ERRCTRL_RSP_ERR,
741 				dev_info->vbase + REG_ERRCTRL_OFFSET);
742 
743 	if (linkerr & HT_LINKERR_DETECTED)
744 		__raw_writel(HT_LINKERR_DETECTED,
745 				dev_info->vbase + REG_LINKERR_OFFSET);
746 
747 	edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
748 }
749 
750 static struct cpc925_dev_info cpc925_devs[] = {
751 	{
752 	.ctl_name = CPC925_CPU_ERR_DEV,
753 	.init = cpc925_cpu_init,
754 	.exit = cpc925_cpu_exit,
755 	.check = cpc925_cpu_check,
756 	},
757 	{
758 	.ctl_name = CPC925_HT_LINK_DEV,
759 	.init = cpc925_htlink_init,
760 	.exit = cpc925_htlink_exit,
761 	.check = cpc925_htlink_check,
762 	},
763 	{ }
764 };
765 
766 /*
767  * Add CPU Err detection and HyperTransport Link Err detection
768  * as common "edac_device", they have no corresponding device
769  * nodes in the Open Firmware DTB and we have to add platform
770  * devices for them. Also, they will share the MMIO with that
771  * of memory controller.
772  */
773 static void cpc925_add_edac_devices(void __iomem *vbase)
774 {
775 	struct cpc925_dev_info *dev_info;
776 
777 	if (!vbase) {
778 		cpc925_printk(KERN_ERR, "MMIO not established yet\n");
779 		return;
780 	}
781 
782 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
783 		dev_info->vbase = vbase;
784 		dev_info->pdev = platform_device_register_simple(
785 					dev_info->ctl_name, 0, NULL, 0);
786 		if (IS_ERR(dev_info->pdev)) {
787 			cpc925_printk(KERN_ERR,
788 				"Can't register platform device for %s\n",
789 				dev_info->ctl_name);
790 			continue;
791 		}
792 
793 		/*
794 		 * Don't have to allocate private structure but
795 		 * make use of cpc925_devs[] instead.
796 		 */
797 		dev_info->edac_idx = edac_device_alloc_index();
798 		dev_info->edac_dev =
799 			edac_device_alloc_ctl_info(0, dev_info->ctl_name,
800 				1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
801 		if (!dev_info->edac_dev) {
802 			cpc925_printk(KERN_ERR, "No memory for edac device\n");
803 			goto err1;
804 		}
805 
806 		dev_info->edac_dev->pvt_info = dev_info;
807 		dev_info->edac_dev->dev = &dev_info->pdev->dev;
808 		dev_info->edac_dev->ctl_name = dev_info->ctl_name;
809 		dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
810 		dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
811 
812 		if (edac_op_state == EDAC_OPSTATE_POLL)
813 			dev_info->edac_dev->edac_check = dev_info->check;
814 
815 		if (dev_info->init)
816 			dev_info->init(dev_info);
817 
818 		if (edac_device_add_device(dev_info->edac_dev) > 0) {
819 			cpc925_printk(KERN_ERR,
820 				"Unable to add edac device for %s\n",
821 				dev_info->ctl_name);
822 			goto err2;
823 		}
824 
825 		edac_dbg(0, "Successfully added edac device for %s\n",
826 			 dev_info->ctl_name);
827 
828 		continue;
829 
830 err2:
831 		if (dev_info->exit)
832 			dev_info->exit(dev_info);
833 		edac_device_free_ctl_info(dev_info->edac_dev);
834 err1:
835 		platform_device_unregister(dev_info->pdev);
836 	}
837 }
838 
839 /*
840  * Delete the common "edac_device" for CPU Err Detection
841  * and HyperTransport Link Err Detection
842  */
843 static void cpc925_del_edac_devices(void)
844 {
845 	struct cpc925_dev_info *dev_info;
846 
847 	for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
848 		if (dev_info->edac_dev) {
849 			edac_device_del_device(dev_info->edac_dev->dev);
850 			edac_device_free_ctl_info(dev_info->edac_dev);
851 			platform_device_unregister(dev_info->pdev);
852 		}
853 
854 		if (dev_info->exit)
855 			dev_info->exit(dev_info);
856 
857 		edac_dbg(0, "Successfully deleted edac device for %s\n",
858 			 dev_info->ctl_name);
859 	}
860 }
861 
862 /* Convert current back-ground scrub rate into byte/sec bandwidth */
863 static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
864 {
865 	struct cpc925_mc_pdata *pdata = mci->pvt_info;
866 	int bw;
867 	u32 mscr;
868 	u8 si;
869 
870 	mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
871 	si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
872 
873 	edac_dbg(0, "Mem Scrub Ctrl Register 0x%x\n", mscr);
874 
875 	if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
876 	    (si == 0)) {
877 		cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
878 		bw = 0;
879 	} else
880 		bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
881 
882 	return bw;
883 }
884 
885 /* Return 0 for single channel; 1 for dual channel */
886 static int cpc925_mc_get_channels(void __iomem *vbase)
887 {
888 	int dual = 0;
889 	u32 mbcr;
890 
891 	mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
892 
893 	/*
894 	 * Dual channel only when 128-bit wide physical bus
895 	 * and 128-bit configuration.
896 	 */
897 	if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
898 	    ((mbcr & MBCR_64BITBUS_MASK) == 0))
899 		dual = 1;
900 
901 	edac_dbg(0, "%s channel\n", (dual > 0) ? "Dual" : "Single");
902 
903 	return dual;
904 }
905 
906 static int cpc925_probe(struct platform_device *pdev)
907 {
908 	static int edac_mc_idx;
909 	struct mem_ctl_info *mci;
910 	struct edac_mc_layer layers[2];
911 	void __iomem *vbase;
912 	struct cpc925_mc_pdata *pdata;
913 	struct resource *r;
914 	int res = 0, nr_channels;
915 
916 	edac_dbg(0, "%s platform device found!\n", pdev->name);
917 
918 	if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
919 		res = -ENOMEM;
920 		goto out;
921 	}
922 
923 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
924 	if (!r) {
925 		cpc925_printk(KERN_ERR, "Unable to get resource\n");
926 		res = -ENOENT;
927 		goto err1;
928 	}
929 
930 	if (!devm_request_mem_region(&pdev->dev,
931 				     r->start,
932 				     resource_size(r),
933 				     pdev->name)) {
934 		cpc925_printk(KERN_ERR, "Unable to request mem region\n");
935 		res = -EBUSY;
936 		goto err1;
937 	}
938 
939 	vbase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
940 	if (!vbase) {
941 		cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
942 		res = -ENOMEM;
943 		goto err2;
944 	}
945 
946 	nr_channels = cpc925_mc_get_channels(vbase) + 1;
947 
948 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
949 	layers[0].size = CPC925_NR_CSROWS;
950 	layers[0].is_virt_csrow = true;
951 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
952 	layers[1].size = nr_channels;
953 	layers[1].is_virt_csrow = false;
954 	mci = edac_mc_alloc(edac_mc_idx, ARRAY_SIZE(layers), layers,
955 			    sizeof(struct cpc925_mc_pdata));
956 	if (!mci) {
957 		cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
958 		res = -ENOMEM;
959 		goto err2;
960 	}
961 
962 	pdata = mci->pvt_info;
963 	pdata->vbase = vbase;
964 	pdata->edac_idx = edac_mc_idx++;
965 	pdata->name = pdev->name;
966 
967 	mci->pdev = &pdev->dev;
968 	platform_set_drvdata(pdev, mci);
969 	mci->dev_name = dev_name(&pdev->dev);
970 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
971 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
972 	mci->edac_cap = EDAC_FLAG_SECDED;
973 	mci->mod_name = CPC925_EDAC_MOD_STR;
974 	mci->ctl_name = pdev->name;
975 
976 	if (edac_op_state == EDAC_OPSTATE_POLL)
977 		mci->edac_check = cpc925_mc_check;
978 
979 	mci->ctl_page_to_phys = NULL;
980 	mci->scrub_mode = SCRUB_SW_SRC;
981 	mci->set_sdram_scrub_rate = NULL;
982 	mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
983 
984 	cpc925_init_csrows(mci);
985 
986 	/* Setup memory controller registers */
987 	cpc925_mc_init(mci);
988 
989 	if (edac_mc_add_mc(mci) > 0) {
990 		cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
991 		goto err3;
992 	}
993 
994 	cpc925_add_edac_devices(vbase);
995 
996 	/* get this far and it's successful */
997 	edac_dbg(0, "success\n");
998 
999 	res = 0;
1000 	goto out;
1001 
1002 err3:
1003 	cpc925_mc_exit(mci);
1004 	edac_mc_free(mci);
1005 err2:
1006 	devm_release_mem_region(&pdev->dev, r->start, resource_size(r));
1007 err1:
1008 	devres_release_group(&pdev->dev, cpc925_probe);
1009 out:
1010 	return res;
1011 }
1012 
1013 static int cpc925_remove(struct platform_device *pdev)
1014 {
1015 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
1016 
1017 	/*
1018 	 * Delete common edac devices before edac mc, because
1019 	 * the former share the MMIO of the latter.
1020 	 */
1021 	cpc925_del_edac_devices();
1022 	cpc925_mc_exit(mci);
1023 
1024 	edac_mc_del_mc(&pdev->dev);
1025 	edac_mc_free(mci);
1026 
1027 	return 0;
1028 }
1029 
1030 static struct platform_driver cpc925_edac_driver = {
1031 	.probe = cpc925_probe,
1032 	.remove = cpc925_remove,
1033 	.driver = {
1034 		   .name = "cpc925_edac",
1035 	}
1036 };
1037 
1038 static int __init cpc925_edac_init(void)
1039 {
1040 	int ret = 0;
1041 
1042 	printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
1043 	printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
1044 
1045 	/* Only support POLL mode so far */
1046 	edac_op_state = EDAC_OPSTATE_POLL;
1047 
1048 	ret = platform_driver_register(&cpc925_edac_driver);
1049 	if (ret) {
1050 		printk(KERN_WARNING "Failed to register %s\n",
1051 			CPC925_EDAC_MOD_STR);
1052 	}
1053 
1054 	return ret;
1055 }
1056 
1057 static void __exit cpc925_edac_exit(void)
1058 {
1059 	platform_driver_unregister(&cpc925_edac_driver);
1060 }
1061 
1062 module_init(cpc925_edac_init);
1063 module_exit(cpc925_edac_exit);
1064 
1065 MODULE_LICENSE("GPL");
1066 MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
1067 MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");
1068