xref: /openbmc/linux/drivers/edac/ppc4xx_edac.c (revision 26b32974)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2008 Nuovation System Designs, LLC
4  *   Grant Erickson <gerickson@nuovations.com>
5  */
6 
7 #include <linux/edac.h>
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/of_device.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_platform.h>
16 #include <linux/types.h>
17 
18 #include <asm/dcr.h>
19 
20 #include "edac_module.h"
21 #include "ppc4xx_edac.h"
22 
23 /*
24  * This file implements a driver for monitoring and handling events
25  * associated with the IMB DDR2 ECC controller found in the AMCC/IBM
26  * 405EX[r], 440SP, 440SPe, 460EX, 460GT and 460SX.
27  *
28  * As realized in the 405EX[r], this controller features:
29  *
30  *   - Support for registered- and non-registered DDR1 and DDR2 memory.
31  *   - 32-bit or 16-bit memory interface with optional ECC.
32  *
33  *     o ECC support includes:
34  *
35  *       - 4-bit SEC/DED
36  *       - Aligned-nibble error detect
37  *       - Bypass mode
38  *
39  *   - Two (2) memory banks/ranks.
40  *   - Up to 1 GiB per bank/rank in 32-bit mode and up to 512 MiB per
41  *     bank/rank in 16-bit mode.
42  *
43  * As realized in the 440SP and 440SPe, this controller changes/adds:
44  *
45  *   - 64-bit or 32-bit memory interface with optional ECC.
46  *
47  *     o ECC support includes:
48  *
49  *       - 8-bit SEC/DED
50  *       - Aligned-nibble error detect
51  *       - Bypass mode
52  *
53  *   - Up to 4 GiB per bank/rank in 64-bit mode and up to 2 GiB
54  *     per bank/rank in 32-bit mode.
55  *
56  * As realized in the 460EX and 460GT, this controller changes/adds:
57  *
58  *   - 64-bit or 32-bit memory interface with optional ECC.
59  *
60  *     o ECC support includes:
61  *
62  *       - 8-bit SEC/DED
63  *       - Aligned-nibble error detect
64  *       - Bypass mode
65  *
66  *   - Four (4) memory banks/ranks.
67  *   - Up to 16 GiB per bank/rank in 64-bit mode and up to 8 GiB
68  *     per bank/rank in 32-bit mode.
69  *
70  * At present, this driver has ONLY been tested against the controller
71  * realization in the 405EX[r] on the AMCC Kilauea and Haleakala
72  * boards (256 MiB w/o ECC memory soldered onto the board) and a
73  * proprietary board based on those designs (128 MiB ECC memory, also
74  * soldered onto the board).
75  *
76  * Dynamic feature detection and handling needs to be added for the
77  * other realizations of this controller listed above.
78  *
79  * Eventually, this driver will likely be adapted to the above variant
80  * realizations of this controller as well as broken apart to handle
81  * the other known ECC-capable controllers prevalent in other 4xx
82  * processors:
83  *
84  *   - IBM SDRAM (405GP, 405CR and 405EP) "ibm,sdram-4xx"
85  *   - IBM DDR1 (440GP, 440GX, 440EP and 440GR) "ibm,sdram-4xx-ddr"
86  *   - Denali DDR1/DDR2 (440EPX and 440GRX) "denali,sdram-4xx-ddr2"
87  *
88  * For this controller, unfortunately, correctable errors report
89  * nothing more than the beat/cycle and byte/lane the correction
90  * occurred on and the check bit group that covered the error.
91  *
92  * In contrast, uncorrectable errors also report the failing address,
93  * the bus master and the transaction direction (i.e. read or write)
94  *
95  * Regardless of whether the error is a CE or a UE, we report the
96  * following pieces of information in the driver-unique message to the
97  * EDAC subsystem:
98  *
99  *   - Device tree path
100  *   - Bank(s)
101  *   - Check bit error group
102  *   - Beat(s)/lane(s)
103  */
104 
105 /* Preprocessor Definitions */
106 
107 #define EDAC_OPSTATE_INT_STR		"interrupt"
108 #define EDAC_OPSTATE_POLL_STR		"polled"
109 #define EDAC_OPSTATE_UNKNOWN_STR	"unknown"
110 
111 #define PPC4XX_EDAC_MODULE_NAME		"ppc4xx_edac"
112 #define PPC4XX_EDAC_MODULE_REVISION	"v1.0.0"
113 
114 #define PPC4XX_EDAC_MESSAGE_SIZE	256
115 
116 /*
117  * Kernel logging without an EDAC instance
118  */
119 #define ppc4xx_edac_printk(level, fmt, arg...) \
120 	edac_printk(level, "PPC4xx MC", fmt, ##arg)
121 
122 /*
123  * Kernel logging with an EDAC instance
124  */
125 #define ppc4xx_edac_mc_printk(level, mci, fmt, arg...) \
126 	edac_mc_chipset_printk(mci, level, "PPC4xx", fmt, ##arg)
127 
128 /*
129  * Macros to convert bank configuration size enumerations into MiB and
130  * page values.
131  */
132 #define SDRAM_MBCF_SZ_MiB_MIN		4
133 #define SDRAM_MBCF_SZ_TO_MiB(n)		(SDRAM_MBCF_SZ_MiB_MIN \
134 					 << (SDRAM_MBCF_SZ_DECODE(n)))
135 #define SDRAM_MBCF_SZ_TO_PAGES(n)	(SDRAM_MBCF_SZ_MiB_MIN \
136 					 << (20 - PAGE_SHIFT + \
137 					     SDRAM_MBCF_SZ_DECODE(n)))
138 
139 /*
140  * The ibm,sdram-4xx-ddr2 Device Control Registers (DCRs) are
141  * indirectly accessed and have a base and length defined by the
142  * device tree. The base can be anything; however, we expect the
143  * length to be precisely two registers, the first for the address
144  * window and the second for the data window.
145  */
146 #define SDRAM_DCR_RESOURCE_LEN		2
147 #define SDRAM_DCR_ADDR_OFFSET		0
148 #define SDRAM_DCR_DATA_OFFSET		1
149 
150 /*
151  * Device tree interrupt indices
152  */
153 #define INTMAP_ECCDED_INDEX		0	/* Double-bit Error Detect */
154 #define INTMAP_ECCSEC_INDEX		1	/* Single-bit Error Correct */
155 
156 /* Type Definitions */
157 
158 /*
159  * PPC4xx SDRAM memory controller private instance data
160  */
161 struct ppc4xx_edac_pdata {
162 	dcr_host_t dcr_host;	/* Indirect DCR address/data window mapping */
163 	struct {
164 		int sec;	/* Single-bit correctable error IRQ assigned */
165 		int ded;	/* Double-bit detectable error IRQ assigned */
166 	} irqs;
167 };
168 
169 /*
170  * Various status data gathered and manipulated when checking and
171  * reporting ECC status.
172  */
173 struct ppc4xx_ecc_status {
174 	u32 ecces;
175 	u32 besr;
176 	u32 bearh;
177 	u32 bearl;
178 	u32 wmirq;
179 };
180 
181 /* Global Variables */
182 
183 /*
184  * Device tree node type and compatible tuples this driver can match
185  * on.
186  */
187 static const struct of_device_id ppc4xx_edac_match[] = {
188 	{
189 		.compatible	= "ibm,sdram-4xx-ddr2"
190 	},
191 	{ }
192 };
193 MODULE_DEVICE_TABLE(of, ppc4xx_edac_match);
194 
195 /*
196  * TODO: The row and channel parameters likely need to be dynamically
197  * set based on the aforementioned variant controller realizations.
198  */
199 static const unsigned ppc4xx_edac_nr_csrows = 2;
200 static const unsigned ppc4xx_edac_nr_chans = 1;
201 
202 /*
203  * Strings associated with PLB master IDs capable of being posted in
204  * SDRAM_BESR or SDRAM_WMIRQ on uncorrectable ECC errors.
205  */
206 static const char * const ppc4xx_plb_masters[9] = {
207 	[SDRAM_PLB_M0ID_ICU]	= "ICU",
208 	[SDRAM_PLB_M0ID_PCIE0]	= "PCI-E 0",
209 	[SDRAM_PLB_M0ID_PCIE1]	= "PCI-E 1",
210 	[SDRAM_PLB_M0ID_DMA]	= "DMA",
211 	[SDRAM_PLB_M0ID_DCU]	= "DCU",
212 	[SDRAM_PLB_M0ID_OPB]	= "OPB",
213 	[SDRAM_PLB_M0ID_MAL]	= "MAL",
214 	[SDRAM_PLB_M0ID_SEC]	= "SEC",
215 	[SDRAM_PLB_M0ID_AHB]	= "AHB"
216 };
217 
218 /**
219  * mfsdram - read and return controller register data
220  * @dcr_host: A pointer to the DCR mapping.
221  * @idcr_n: The indirect DCR register to read.
222  *
223  * This routine reads and returns the data associated with the
224  * controller's specified indirect DCR register.
225  *
226  * Returns the read data.
227  */
228 static inline u32
229 mfsdram(const dcr_host_t *dcr_host, unsigned int idcr_n)
230 {
231 	return __mfdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
232 			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
233 			idcr_n);
234 }
235 
236 /**
237  * mtsdram - write controller register data
238  * @dcr_host: A pointer to the DCR mapping.
239  * @idcr_n: The indirect DCR register to write.
240  * @value: The data to write.
241  *
242  * This routine writes the provided data to the controller's specified
243  * indirect DCR register.
244  */
245 static inline void
246 mtsdram(const dcr_host_t *dcr_host, unsigned int idcr_n, u32 value)
247 {
248 	return __mtdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
249 			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
250 			idcr_n,
251 			value);
252 }
253 
254 /**
255  * ppc4xx_edac_check_bank_error - check a bank for an ECC bank error
256  * @status: A pointer to the ECC status structure to check for an
257  *          ECC bank error.
258  * @bank: The bank to check for an ECC error.
259  *
260  * This routine determines whether the specified bank has an ECC
261  * error.
262  *
263  * Returns true if the specified bank has an ECC error; otherwise,
264  * false.
265  */
266 static bool
267 ppc4xx_edac_check_bank_error(const struct ppc4xx_ecc_status *status,
268 			     unsigned int bank)
269 {
270 	switch (bank) {
271 	case 0:
272 		return status->ecces & SDRAM_ECCES_BK0ER;
273 	case 1:
274 		return status->ecces & SDRAM_ECCES_BK1ER;
275 	default:
276 		return false;
277 	}
278 }
279 
280 /**
281  * ppc4xx_edac_generate_bank_message - generate interpretted bank status message
282  * @mci: A pointer to the EDAC memory controller instance associated
283  *       with the bank message being generated.
284  * @status: A pointer to the ECC status structure to generate the
285  *          message from.
286  * @buffer: A pointer to the buffer in which to generate the
287  *          message.
288  * @size: The size, in bytes, of space available in buffer.
289  *
290  * This routine generates to the provided buffer the portion of the
291  * driver-unique report message associated with the ECCESS[BKNER]
292  * field of the specified ECC status.
293  *
294  * Returns the number of characters generated on success; otherwise, <
295  * 0 on error.
296  */
297 static int
298 ppc4xx_edac_generate_bank_message(const struct mem_ctl_info *mci,
299 				  const struct ppc4xx_ecc_status *status,
300 				  char *buffer,
301 				  size_t size)
302 {
303 	int n, total = 0;
304 	unsigned int row, rows;
305 
306 	n = snprintf(buffer, size, "%s: Banks: ", mci->dev_name);
307 
308 	if (n < 0 || n >= size)
309 		goto fail;
310 
311 	buffer += n;
312 	size -= n;
313 	total += n;
314 
315 	for (rows = 0, row = 0; row < mci->nr_csrows; row++) {
316 		if (ppc4xx_edac_check_bank_error(status, row)) {
317 			n = snprintf(buffer, size, "%s%u",
318 					(rows++ ? ", " : ""), row);
319 
320 			if (n < 0 || n >= size)
321 				goto fail;
322 
323 			buffer += n;
324 			size -= n;
325 			total += n;
326 		}
327 	}
328 
329 	n = snprintf(buffer, size, "%s; ", rows ? "" : "None");
330 
331 	if (n < 0 || n >= size)
332 		goto fail;
333 
334 	buffer += n;
335 	size -= n;
336 	total += n;
337 
338  fail:
339 	return total;
340 }
341 
342 /**
343  * ppc4xx_edac_generate_checkbit_message - generate interpretted checkbit message
344  * @mci: A pointer to the EDAC memory controller instance associated
345  *       with the checkbit message being generated.
346  * @status: A pointer to the ECC status structure to generate the
347  *          message from.
348  * @buffer: A pointer to the buffer in which to generate the
349  *          message.
350  * @size: The size, in bytes, of space available in buffer.
351  *
352  * This routine generates to the provided buffer the portion of the
353  * driver-unique report message associated with the ECCESS[CKBER]
354  * field of the specified ECC status.
355  *
356  * Returns the number of characters generated on success; otherwise, <
357  * 0 on error.
358  */
359 static int
360 ppc4xx_edac_generate_checkbit_message(const struct mem_ctl_info *mci,
361 				      const struct ppc4xx_ecc_status *status,
362 				      char *buffer,
363 				      size_t size)
364 {
365 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
366 	const char *ckber = NULL;
367 
368 	switch (status->ecces & SDRAM_ECCES_CKBER_MASK) {
369 	case SDRAM_ECCES_CKBER_NONE:
370 		ckber = "None";
371 		break;
372 	case SDRAM_ECCES_CKBER_32_ECC_0_3:
373 		ckber = "ECC0:3";
374 		break;
375 	case SDRAM_ECCES_CKBER_32_ECC_4_8:
376 		switch (mfsdram(&pdata->dcr_host, SDRAM_MCOPT1) &
377 			SDRAM_MCOPT1_WDTH_MASK) {
378 		case SDRAM_MCOPT1_WDTH_16:
379 			ckber = "ECC0:3";
380 			break;
381 		case SDRAM_MCOPT1_WDTH_32:
382 			ckber = "ECC4:8";
383 			break;
384 		default:
385 			ckber = "Unknown";
386 			break;
387 		}
388 		break;
389 	case SDRAM_ECCES_CKBER_32_ECC_0_8:
390 		ckber = "ECC0:8";
391 		break;
392 	default:
393 		ckber = "Unknown";
394 		break;
395 	}
396 
397 	return snprintf(buffer, size, "Checkbit Error: %s", ckber);
398 }
399 
400 /**
401  * ppc4xx_edac_generate_lane_message - generate interpretted byte lane message
402  * @mci: A pointer to the EDAC memory controller instance associated
403  *       with the byte lane message being generated.
404  * @status: A pointer to the ECC status structure to generate the
405  *          message from.
406  * @buffer: A pointer to the buffer in which to generate the
407  *          message.
408  * @size: The size, in bytes, of space available in buffer.
409  *
410  * This routine generates to the provided buffer the portion of the
411  * driver-unique report message associated with the ECCESS[BNCE]
412  * field of the specified ECC status.
413  *
414  * Returns the number of characters generated on success; otherwise, <
415  * 0 on error.
416  */
417 static int
418 ppc4xx_edac_generate_lane_message(const struct mem_ctl_info *mci,
419 				  const struct ppc4xx_ecc_status *status,
420 				  char *buffer,
421 				  size_t size)
422 {
423 	int n, total = 0;
424 	unsigned int lane, lanes;
425 	const unsigned int first_lane = 0;
426 	const unsigned int lane_count = 16;
427 
428 	n = snprintf(buffer, size, "; Byte Lane Errors: ");
429 
430 	if (n < 0 || n >= size)
431 		goto fail;
432 
433 	buffer += n;
434 	size -= n;
435 	total += n;
436 
437 	for (lanes = 0, lane = first_lane; lane < lane_count; lane++) {
438 		if ((status->ecces & SDRAM_ECCES_BNCE_ENCODE(lane)) != 0) {
439 			n = snprintf(buffer, size,
440 				     "%s%u",
441 				     (lanes++ ? ", " : ""), lane);
442 
443 			if (n < 0 || n >= size)
444 				goto fail;
445 
446 			buffer += n;
447 			size -= n;
448 			total += n;
449 		}
450 	}
451 
452 	n = snprintf(buffer, size, "%s; ", lanes ? "" : "None");
453 
454 	if (n < 0 || n >= size)
455 		goto fail;
456 
457 	buffer += n;
458 	size -= n;
459 	total += n;
460 
461  fail:
462 	return total;
463 }
464 
465 /**
466  * ppc4xx_edac_generate_ecc_message - generate interpretted ECC status message
467  * @mci: A pointer to the EDAC memory controller instance associated
468  *       with the ECCES message being generated.
469  * @status: A pointer to the ECC status structure to generate the
470  *          message from.
471  * @buffer: A pointer to the buffer in which to generate the
472  *          message.
473  * @size: The size, in bytes, of space available in buffer.
474  *
475  * This routine generates to the provided buffer the portion of the
476  * driver-unique report message associated with the ECCESS register of
477  * the specified ECC status.
478  *
479  * Returns the number of characters generated on success; otherwise, <
480  * 0 on error.
481  */
482 static int
483 ppc4xx_edac_generate_ecc_message(const struct mem_ctl_info *mci,
484 				 const struct ppc4xx_ecc_status *status,
485 				 char *buffer,
486 				 size_t size)
487 {
488 	int n, total = 0;
489 
490 	n = ppc4xx_edac_generate_bank_message(mci, status, buffer, size);
491 
492 	if (n < 0 || n >= size)
493 		goto fail;
494 
495 	buffer += n;
496 	size -= n;
497 	total += n;
498 
499 	n = ppc4xx_edac_generate_checkbit_message(mci, status, buffer, size);
500 
501 	if (n < 0 || n >= size)
502 		goto fail;
503 
504 	buffer += n;
505 	size -= n;
506 	total += n;
507 
508 	n = ppc4xx_edac_generate_lane_message(mci, status, buffer, size);
509 
510 	if (n < 0 || n >= size)
511 		goto fail;
512 
513 	buffer += n;
514 	size -= n;
515 	total += n;
516 
517  fail:
518 	return total;
519 }
520 
521 /**
522  * ppc4xx_edac_generate_plb_message - generate interpretted PLB status message
523  * @mci: A pointer to the EDAC memory controller instance associated
524  *       with the PLB message being generated.
525  * @status: A pointer to the ECC status structure to generate the
526  *          message from.
527  * @buffer: A pointer to the buffer in which to generate the
528  *          message.
529  * @size: The size, in bytes, of space available in buffer.
530  *
531  * This routine generates to the provided buffer the portion of the
532  * driver-unique report message associated with the PLB-related BESR
533  * and/or WMIRQ registers of the specified ECC status.
534  *
535  * Returns the number of characters generated on success; otherwise, <
536  * 0 on error.
537  */
538 static int
539 ppc4xx_edac_generate_plb_message(const struct mem_ctl_info *mci,
540 				 const struct ppc4xx_ecc_status *status,
541 				 char *buffer,
542 				 size_t size)
543 {
544 	unsigned int master;
545 	bool read;
546 
547 	if ((status->besr & SDRAM_BESR_MASK) == 0)
548 		return 0;
549 
550 	if ((status->besr & SDRAM_BESR_M0ET_MASK) == SDRAM_BESR_M0ET_NONE)
551 		return 0;
552 
553 	read = ((status->besr & SDRAM_BESR_M0RW_MASK) == SDRAM_BESR_M0RW_READ);
554 
555 	master = SDRAM_BESR_M0ID_DECODE(status->besr);
556 
557 	return snprintf(buffer, size,
558 			"%s error w/ PLB master %u \"%s\"; ",
559 			(read ? "Read" : "Write"),
560 			master,
561 			(((master >= SDRAM_PLB_M0ID_FIRST) &&
562 			  (master <= SDRAM_PLB_M0ID_LAST)) ?
563 			 ppc4xx_plb_masters[master] : "UNKNOWN"));
564 }
565 
566 /**
567  * ppc4xx_edac_generate_message - generate interpretted status message
568  * @mci: A pointer to the EDAC memory controller instance associated
569  *       with the driver-unique message being generated.
570  * @status: A pointer to the ECC status structure to generate the
571  *          message from.
572  * @buffer: A pointer to the buffer in which to generate the
573  *          message.
574  * @size: The size, in bytes, of space available in buffer.
575  *
576  * This routine generates to the provided buffer the driver-unique
577  * EDAC report message from the specified ECC status.
578  */
579 static void
580 ppc4xx_edac_generate_message(const struct mem_ctl_info *mci,
581 			     const struct ppc4xx_ecc_status *status,
582 			     char *buffer,
583 			     size_t size)
584 {
585 	int n;
586 
587 	if (buffer == NULL || size == 0)
588 		return;
589 
590 	n = ppc4xx_edac_generate_ecc_message(mci, status, buffer, size);
591 
592 	if (n < 0 || n >= size)
593 		return;
594 
595 	buffer += n;
596 	size -= n;
597 
598 	ppc4xx_edac_generate_plb_message(mci, status, buffer, size);
599 }
600 
601 #ifdef DEBUG
602 /**
603  * ppc4xx_ecc_dump_status - dump controller ECC status registers
604  * @mci: A pointer to the EDAC memory controller instance
605  *       associated with the status being dumped.
606  * @status: A pointer to the ECC status structure to generate the
607  *          dump from.
608  *
609  * This routine dumps to the kernel log buffer the raw and
610  * interpretted specified ECC status.
611  */
612 static void
613 ppc4xx_ecc_dump_status(const struct mem_ctl_info *mci,
614 		       const struct ppc4xx_ecc_status *status)
615 {
616 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
617 
618 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
619 
620 	ppc4xx_edac_mc_printk(KERN_INFO, mci,
621 			      "\n"
622 			      "\tECCES: 0x%08x\n"
623 			      "\tWMIRQ: 0x%08x\n"
624 			      "\tBESR:  0x%08x\n"
625 			      "\tBEAR:  0x%08x%08x\n"
626 			      "\t%s\n",
627 			      status->ecces,
628 			      status->wmirq,
629 			      status->besr,
630 			      status->bearh,
631 			      status->bearl,
632 			      message);
633 }
634 #endif /* DEBUG */
635 
636 /**
637  * ppc4xx_ecc_get_status - get controller ECC status
638  * @mci: A pointer to the EDAC memory controller instance
639  *       associated with the status being retrieved.
640  * @status: A pointer to the ECC status structure to populate the
641  *          ECC status with.
642  *
643  * This routine reads and masks, as appropriate, all the relevant
644  * status registers that deal with ibm,sdram-4xx-ddr2 ECC errors.
645  * While we read all of them, for correctable errors, we only expect
646  * to deal with ECCES. For uncorrectable errors, we expect to deal
647  * with all of them.
648  */
649 static void
650 ppc4xx_ecc_get_status(const struct mem_ctl_info *mci,
651 		      struct ppc4xx_ecc_status *status)
652 {
653 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
654 	const dcr_host_t *dcr_host = &pdata->dcr_host;
655 
656 	status->ecces = mfsdram(dcr_host, SDRAM_ECCES) & SDRAM_ECCES_MASK;
657 	status->wmirq = mfsdram(dcr_host, SDRAM_WMIRQ) & SDRAM_WMIRQ_MASK;
658 	status->besr  = mfsdram(dcr_host, SDRAM_BESR)  & SDRAM_BESR_MASK;
659 	status->bearl = mfsdram(dcr_host, SDRAM_BEARL);
660 	status->bearh = mfsdram(dcr_host, SDRAM_BEARH);
661 }
662 
663 /**
664  * ppc4xx_ecc_clear_status - clear controller ECC status
665  * @mci: A pointer to the EDAC memory controller instance
666  *       associated with the status being cleared.
667  * @status: A pointer to the ECC status structure containing the
668  *          values to write to clear the ECC status.
669  *
670  * This routine clears--by writing the masked (as appropriate) status
671  * values back to--the status registers that deal with
672  * ibm,sdram-4xx-ddr2 ECC errors.
673  */
674 static void
675 ppc4xx_ecc_clear_status(const struct mem_ctl_info *mci,
676 			const struct ppc4xx_ecc_status *status)
677 {
678 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
679 	const dcr_host_t *dcr_host = &pdata->dcr_host;
680 
681 	mtsdram(dcr_host, SDRAM_ECCES,	status->ecces & SDRAM_ECCES_MASK);
682 	mtsdram(dcr_host, SDRAM_WMIRQ,	status->wmirq & SDRAM_WMIRQ_MASK);
683 	mtsdram(dcr_host, SDRAM_BESR,	status->besr & SDRAM_BESR_MASK);
684 	mtsdram(dcr_host, SDRAM_BEARL,	0);
685 	mtsdram(dcr_host, SDRAM_BEARH,	0);
686 }
687 
688 /**
689  * ppc4xx_edac_handle_ce - handle controller correctable ECC error (CE)
690  * @mci: A pointer to the EDAC memory controller instance
691  *       associated with the correctable error being handled and reported.
692  * @status: A pointer to the ECC status structure associated with
693  *          the correctable error being handled and reported.
694  *
695  * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
696  * correctable error. Per the aforementioned discussion, there's not
697  * enough status available to use the full EDAC correctable error
698  * interface, so we just pass driver-unique message to the "no info"
699  * interface.
700  */
701 static void
702 ppc4xx_edac_handle_ce(struct mem_ctl_info *mci,
703 		      const struct ppc4xx_ecc_status *status)
704 {
705 	int row;
706 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
707 
708 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
709 
710 	for (row = 0; row < mci->nr_csrows; row++)
711 		if (ppc4xx_edac_check_bank_error(status, row))
712 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
713 					     0, 0, 0,
714 					     row, 0, -1,
715 					     message, "");
716 }
717 
718 /**
719  * ppc4xx_edac_handle_ue - handle controller uncorrectable ECC error (UE)
720  * @mci: A pointer to the EDAC memory controller instance
721  *       associated with the uncorrectable error being handled and
722  *       reported.
723  * @status: A pointer to the ECC status structure associated with
724  *          the uncorrectable error being handled and reported.
725  *
726  * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
727  * uncorrectable error.
728  */
729 static void
730 ppc4xx_edac_handle_ue(struct mem_ctl_info *mci,
731 		      const struct ppc4xx_ecc_status *status)
732 {
733 	const u64 bear = ((u64)status->bearh << 32 | status->bearl);
734 	const unsigned long page = bear >> PAGE_SHIFT;
735 	const unsigned long offset = bear & ~PAGE_MASK;
736 	int row;
737 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
738 
739 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
740 
741 	for (row = 0; row < mci->nr_csrows; row++)
742 		if (ppc4xx_edac_check_bank_error(status, row))
743 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
744 					     page, offset, 0,
745 					     row, 0, -1,
746 					     message, "");
747 }
748 
749 /**
750  * ppc4xx_edac_check - check controller for ECC errors
751  * @mci: A pointer to the EDAC memory controller instance
752  *       associated with the ibm,sdram-4xx-ddr2 controller being
753  *       checked.
754  *
755  * This routine is used to check and post ECC errors and is called by
756  * both the EDAC polling thread and this driver's CE and UE interrupt
757  * handler.
758  */
759 static void
760 ppc4xx_edac_check(struct mem_ctl_info *mci)
761 {
762 #ifdef DEBUG
763 	static unsigned int count;
764 #endif
765 	struct ppc4xx_ecc_status status;
766 
767 	ppc4xx_ecc_get_status(mci, &status);
768 
769 #ifdef DEBUG
770 	if (count++ % 30 == 0)
771 		ppc4xx_ecc_dump_status(mci, &status);
772 #endif
773 
774 	if (status.ecces & SDRAM_ECCES_UE)
775 		ppc4xx_edac_handle_ue(mci, &status);
776 
777 	if (status.ecces & SDRAM_ECCES_CE)
778 		ppc4xx_edac_handle_ce(mci, &status);
779 
780 	ppc4xx_ecc_clear_status(mci, &status);
781 }
782 
783 /**
784  * ppc4xx_edac_isr - SEC (CE) and DED (UE) interrupt service routine
785  * @irq:    The virtual interrupt number being serviced.
786  * @dev_id: A pointer to the EDAC memory controller instance
787  *          associated with the interrupt being handled.
788  *
789  * This routine implements the interrupt handler for both correctable
790  * (CE) and uncorrectable (UE) ECC errors for the ibm,sdram-4xx-ddr2
791  * controller. It simply calls through to the same routine used during
792  * polling to check, report and clear the ECC status.
793  *
794  * Unconditionally returns IRQ_HANDLED.
795  */
796 static irqreturn_t
797 ppc4xx_edac_isr(int irq, void *dev_id)
798 {
799 	struct mem_ctl_info *mci = dev_id;
800 
801 	ppc4xx_edac_check(mci);
802 
803 	return IRQ_HANDLED;
804 }
805 
806 /**
807  * ppc4xx_edac_get_dtype - return the controller memory width
808  * @mcopt1: The 32-bit Memory Controller Option 1 register value
809  *          currently set for the controller, from which the width
810  *          is derived.
811  *
812  * This routine returns the EDAC device type width appropriate for the
813  * current controller configuration.
814  *
815  * TODO: This needs to be conditioned dynamically through feature
816  * flags or some such when other controller variants are supported as
817  * the 405EX[r] is 16-/32-bit and the others are 32-/64-bit with the
818  * 16- and 64-bit field definition/value/enumeration (b1) overloaded
819  * among them.
820  *
821  * Returns a device type width enumeration.
822  */
823 static enum dev_type ppc4xx_edac_get_dtype(u32 mcopt1)
824 {
825 	switch (mcopt1 & SDRAM_MCOPT1_WDTH_MASK) {
826 	case SDRAM_MCOPT1_WDTH_16:
827 		return DEV_X2;
828 	case SDRAM_MCOPT1_WDTH_32:
829 		return DEV_X4;
830 	default:
831 		return DEV_UNKNOWN;
832 	}
833 }
834 
835 /**
836  * ppc4xx_edac_get_mtype - return controller memory type
837  * @mcopt1: The 32-bit Memory Controller Option 1 register value
838  *          currently set for the controller, from which the memory type
839  *          is derived.
840  *
841  * This routine returns the EDAC memory type appropriate for the
842  * current controller configuration.
843  *
844  * Returns a memory type enumeration.
845  */
846 static enum mem_type ppc4xx_edac_get_mtype(u32 mcopt1)
847 {
848 	bool rden = ((mcopt1 & SDRAM_MCOPT1_RDEN_MASK) == SDRAM_MCOPT1_RDEN);
849 
850 	switch (mcopt1 & SDRAM_MCOPT1_DDR_TYPE_MASK) {
851 	case SDRAM_MCOPT1_DDR2_TYPE:
852 		return rden ? MEM_RDDR2 : MEM_DDR2;
853 	case SDRAM_MCOPT1_DDR1_TYPE:
854 		return rden ? MEM_RDDR : MEM_DDR;
855 	default:
856 		return MEM_UNKNOWN;
857 	}
858 }
859 
860 /**
861  * ppc4xx_edac_init_csrows - initialize driver instance rows
862  * @mci: A pointer to the EDAC memory controller instance
863  *       associated with the ibm,sdram-4xx-ddr2 controller for which
864  *       the csrows (i.e. banks/ranks) are being initialized.
865  * @mcopt1: The 32-bit Memory Controller Option 1 register value
866  *          currently set for the controller, from which bank width
867  *          and memory typ information is derived.
868  *
869  * This routine initializes the virtual "chip select rows" associated
870  * with the EDAC memory controller instance. An ibm,sdram-4xx-ddr2
871  * controller bank/rank is mapped to a row.
872  *
873  * Returns 0 if OK; otherwise, -EINVAL if the memory bank size
874  * configuration cannot be determined.
875  */
876 static int ppc4xx_edac_init_csrows(struct mem_ctl_info *mci, u32 mcopt1)
877 {
878 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
879 	int status = 0;
880 	enum mem_type mtype;
881 	enum dev_type dtype;
882 	enum edac_type edac_mode;
883 	int row, j;
884 	u32 mbxcf, size, nr_pages;
885 
886 	/* Establish the memory type and width */
887 
888 	mtype = ppc4xx_edac_get_mtype(mcopt1);
889 	dtype = ppc4xx_edac_get_dtype(mcopt1);
890 
891 	/* Establish EDAC mode */
892 
893 	if (mci->edac_cap & EDAC_FLAG_SECDED)
894 		edac_mode = EDAC_SECDED;
895 	else if (mci->edac_cap & EDAC_FLAG_EC)
896 		edac_mode = EDAC_EC;
897 	else
898 		edac_mode = EDAC_NONE;
899 
900 	/*
901 	 * Initialize each chip select row structure which correspond
902 	 * 1:1 with a controller bank/rank.
903 	 */
904 
905 	for (row = 0; row < mci->nr_csrows; row++) {
906 		struct csrow_info *csi = mci->csrows[row];
907 
908 		/*
909 		 * Get the configuration settings for this
910 		 * row/bank/rank and skip disabled banks.
911 		 */
912 
913 		mbxcf = mfsdram(&pdata->dcr_host, SDRAM_MBXCF(row));
914 
915 		if ((mbxcf & SDRAM_MBCF_BE_MASK) != SDRAM_MBCF_BE_ENABLE)
916 			continue;
917 
918 		/* Map the bank configuration size setting to pages. */
919 
920 		size = mbxcf & SDRAM_MBCF_SZ_MASK;
921 
922 		switch (size) {
923 		case SDRAM_MBCF_SZ_4MB:
924 		case SDRAM_MBCF_SZ_8MB:
925 		case SDRAM_MBCF_SZ_16MB:
926 		case SDRAM_MBCF_SZ_32MB:
927 		case SDRAM_MBCF_SZ_64MB:
928 		case SDRAM_MBCF_SZ_128MB:
929 		case SDRAM_MBCF_SZ_256MB:
930 		case SDRAM_MBCF_SZ_512MB:
931 		case SDRAM_MBCF_SZ_1GB:
932 		case SDRAM_MBCF_SZ_2GB:
933 		case SDRAM_MBCF_SZ_4GB:
934 		case SDRAM_MBCF_SZ_8GB:
935 			nr_pages = SDRAM_MBCF_SZ_TO_PAGES(size);
936 			break;
937 		default:
938 			ppc4xx_edac_mc_printk(KERN_ERR, mci,
939 					      "Unrecognized memory bank %d "
940 					      "size 0x%08x\n",
941 					      row, SDRAM_MBCF_SZ_DECODE(size));
942 			status = -EINVAL;
943 			goto done;
944 		}
945 
946 		/*
947 		 * It's unclear exactly what grain should be set to
948 		 * here. The SDRAM_ECCES register allows resolution of
949 		 * an error down to a nibble which would potentially
950 		 * argue for a grain of '1' byte, even though we only
951 		 * know the associated address for uncorrectable
952 		 * errors. This value is not used at present for
953 		 * anything other than error reporting so getting it
954 		 * wrong should be of little consequence. Other
955 		 * possible values would be the PLB width (16), the
956 		 * page size (PAGE_SIZE) or the memory width (2 or 4).
957 		 */
958 		for (j = 0; j < csi->nr_channels; j++) {
959 			struct dimm_info *dimm = csi->channels[j]->dimm;
960 
961 			dimm->nr_pages  = nr_pages / csi->nr_channels;
962 			dimm->grain	= 1;
963 
964 			dimm->mtype	= mtype;
965 			dimm->dtype	= dtype;
966 
967 			dimm->edac_mode	= edac_mode;
968 		}
969 	}
970 
971  done:
972 	return status;
973 }
974 
975 /**
976  * ppc4xx_edac_mc_init - initialize driver instance
977  * @mci: A pointer to the EDAC memory controller instance being
978  *       initialized.
979  * @op: A pointer to the OpenFirmware device tree node associated
980  *      with the controller this EDAC instance is bound to.
981  * @dcr_host: A pointer to the DCR data containing the DCR mapping
982  *            for this controller instance.
983  * @mcopt1: The 32-bit Memory Controller Option 1 register value
984  *          currently set for the controller, from which ECC capabilities
985  *          and scrub mode are derived.
986  *
987  * This routine performs initialization of the EDAC memory controller
988  * instance and related driver-private data associated with the
989  * ibm,sdram-4xx-ddr2 memory controller the instance is bound to.
990  *
991  * Returns 0 if OK; otherwise, < 0 on error.
992  */
993 static int ppc4xx_edac_mc_init(struct mem_ctl_info *mci,
994 			       struct platform_device *op,
995 			       const dcr_host_t *dcr_host, u32 mcopt1)
996 {
997 	int status = 0;
998 	const u32 memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);
999 	struct ppc4xx_edac_pdata *pdata = NULL;
1000 	const struct device_node *np = op->dev.of_node;
1001 
1002 	if (of_match_device(ppc4xx_edac_match, &op->dev) == NULL)
1003 		return -EINVAL;
1004 
1005 	/* Initial driver pointers and private data */
1006 
1007 	mci->pdev		= &op->dev;
1008 
1009 	dev_set_drvdata(mci->pdev, mci);
1010 
1011 	pdata			= mci->pvt_info;
1012 
1013 	pdata->dcr_host		= *dcr_host;
1014 
1015 	/* Initialize controller capabilities and configuration */
1016 
1017 	mci->mtype_cap		= (MEM_FLAG_DDR | MEM_FLAG_RDDR |
1018 				   MEM_FLAG_DDR2 | MEM_FLAG_RDDR2);
1019 
1020 	mci->edac_ctl_cap	= (EDAC_FLAG_NONE |
1021 				   EDAC_FLAG_EC |
1022 				   EDAC_FLAG_SECDED);
1023 
1024 	mci->scrub_cap		= SCRUB_NONE;
1025 	mci->scrub_mode		= SCRUB_NONE;
1026 
1027 	/*
1028 	 * Update the actual capabilites based on the MCOPT1[MCHK]
1029 	 * settings. Scrubbing is only useful if reporting is enabled.
1030 	 */
1031 
1032 	switch (memcheck) {
1033 	case SDRAM_MCOPT1_MCHK_CHK:
1034 		mci->edac_cap	= EDAC_FLAG_EC;
1035 		break;
1036 	case SDRAM_MCOPT1_MCHK_CHK_REP:
1037 		mci->edac_cap	= (EDAC_FLAG_EC | EDAC_FLAG_SECDED);
1038 		mci->scrub_mode	= SCRUB_SW_SRC;
1039 		break;
1040 	default:
1041 		mci->edac_cap	= EDAC_FLAG_NONE;
1042 		break;
1043 	}
1044 
1045 	/* Initialize strings */
1046 
1047 	mci->mod_name		= PPC4XX_EDAC_MODULE_NAME;
1048 	mci->ctl_name		= ppc4xx_edac_match->compatible;
1049 	mci->dev_name		= np->full_name;
1050 
1051 	/* Initialize callbacks */
1052 
1053 	mci->edac_check		= ppc4xx_edac_check;
1054 	mci->ctl_page_to_phys	= NULL;
1055 
1056 	/* Initialize chip select rows */
1057 
1058 	status = ppc4xx_edac_init_csrows(mci, mcopt1);
1059 
1060 	if (status)
1061 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1062 				      "Failed to initialize rows!\n");
1063 
1064 	return status;
1065 }
1066 
1067 /**
1068  * ppc4xx_edac_register_irq - setup and register controller interrupts
1069  * @op: A pointer to the OpenFirmware device tree node associated
1070  *      with the controller this EDAC instance is bound to.
1071  * @mci: A pointer to the EDAC memory controller instance
1072  *       associated with the ibm,sdram-4xx-ddr2 controller for which
1073  *       interrupts are being registered.
1074  *
1075  * This routine parses the correctable (CE) and uncorrectable error (UE)
1076  * interrupts from the device tree node and maps and assigns them to
1077  * the associated EDAC memory controller instance.
1078  *
1079  * Returns 0 if OK; otherwise, -ENODEV if the interrupts could not be
1080  * mapped and assigned.
1081  */
1082 static int ppc4xx_edac_register_irq(struct platform_device *op,
1083 				    struct mem_ctl_info *mci)
1084 {
1085 	int status = 0;
1086 	int ded_irq, sec_irq;
1087 	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
1088 	struct device_node *np = op->dev.of_node;
1089 
1090 	ded_irq = irq_of_parse_and_map(np, INTMAP_ECCDED_INDEX);
1091 	sec_irq = irq_of_parse_and_map(np, INTMAP_ECCSEC_INDEX);
1092 
1093 	if (!ded_irq || !sec_irq) {
1094 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1095 				      "Unable to map interrupts.\n");
1096 		status = -ENODEV;
1097 		goto fail;
1098 	}
1099 
1100 	status = request_irq(ded_irq,
1101 			     ppc4xx_edac_isr,
1102 			     0,
1103 			     "[EDAC] MC ECCDED",
1104 			     mci);
1105 
1106 	if (status < 0) {
1107 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1108 				      "Unable to request irq %d for ECC DED",
1109 				      ded_irq);
1110 		status = -ENODEV;
1111 		goto fail1;
1112 	}
1113 
1114 	status = request_irq(sec_irq,
1115 			     ppc4xx_edac_isr,
1116 			     0,
1117 			     "[EDAC] MC ECCSEC",
1118 			     mci);
1119 
1120 	if (status < 0) {
1121 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1122 				      "Unable to request irq %d for ECC SEC",
1123 				      sec_irq);
1124 		status = -ENODEV;
1125 		goto fail2;
1126 	}
1127 
1128 	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCDED irq is %d\n", ded_irq);
1129 	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCSEC irq is %d\n", sec_irq);
1130 
1131 	pdata->irqs.ded = ded_irq;
1132 	pdata->irqs.sec = sec_irq;
1133 
1134 	return 0;
1135 
1136  fail2:
1137 	free_irq(sec_irq, mci);
1138 
1139  fail1:
1140 	free_irq(ded_irq, mci);
1141 
1142  fail:
1143 	return status;
1144 }
1145 
1146 /**
1147  * ppc4xx_edac_map_dcrs - locate and map controller registers
1148  * @np: A pointer to the device tree node containing the DCR
1149  *      resources to map.
1150  * @dcr_host: A pointer to the DCR data to populate with the
1151  *            DCR mapping.
1152  *
1153  * This routine attempts to locate in the device tree and map the DCR
1154  * register resources associated with the controller's indirect DCR
1155  * address and data windows.
1156  *
1157  * Returns 0 if the DCRs were successfully mapped; otherwise, < 0 on
1158  * error.
1159  */
1160 static int ppc4xx_edac_map_dcrs(const struct device_node *np,
1161 				dcr_host_t *dcr_host)
1162 {
1163 	unsigned int dcr_base, dcr_len;
1164 
1165 	if (np == NULL || dcr_host == NULL)
1166 		return -EINVAL;
1167 
1168 	/* Get the DCR resource extent and sanity check the values. */
1169 
1170 	dcr_base = dcr_resource_start(np, 0);
1171 	dcr_len = dcr_resource_len(np, 0);
1172 
1173 	if (dcr_base == 0 || dcr_len == 0) {
1174 		ppc4xx_edac_printk(KERN_ERR,
1175 				   "Failed to obtain DCR property.\n");
1176 		return -ENODEV;
1177 	}
1178 
1179 	if (dcr_len != SDRAM_DCR_RESOURCE_LEN) {
1180 		ppc4xx_edac_printk(KERN_ERR,
1181 				   "Unexpected DCR length %d, expected %d.\n",
1182 				   dcr_len, SDRAM_DCR_RESOURCE_LEN);
1183 		return -ENODEV;
1184 	}
1185 
1186 	/*  Attempt to map the DCR extent. */
1187 
1188 	*dcr_host = dcr_map(np, dcr_base, dcr_len);
1189 
1190 	if (!DCR_MAP_OK(*dcr_host)) {
1191 		ppc4xx_edac_printk(KERN_INFO, "Failed to map DCRs.\n");
1192 		    return -ENODEV;
1193 	}
1194 
1195 	return 0;
1196 }
1197 
1198 /**
1199  * ppc4xx_edac_probe - check controller and bind driver
1200  * @op: A pointer to the OpenFirmware device tree node associated
1201  *      with the controller being probed for driver binding.
1202  *
1203  * This routine probes a specific ibm,sdram-4xx-ddr2 controller
1204  * instance for binding with the driver.
1205  *
1206  * Returns 0 if the controller instance was successfully bound to the
1207  * driver; otherwise, < 0 on error.
1208  */
1209 static int ppc4xx_edac_probe(struct platform_device *op)
1210 {
1211 	int status = 0;
1212 	u32 mcopt1, memcheck;
1213 	dcr_host_t dcr_host;
1214 	const struct device_node *np = op->dev.of_node;
1215 	struct mem_ctl_info *mci = NULL;
1216 	struct edac_mc_layer layers[2];
1217 	static int ppc4xx_edac_instance;
1218 
1219 	/*
1220 	 * At this point, we only support the controller realized on
1221 	 * the AMCC PPC 405EX[r]. Reject anything else.
1222 	 */
1223 
1224 	if (!of_device_is_compatible(np, "ibm,sdram-405ex") &&
1225 	    !of_device_is_compatible(np, "ibm,sdram-405exr")) {
1226 		ppc4xx_edac_printk(KERN_NOTICE,
1227 				   "Only the PPC405EX[r] is supported.\n");
1228 		return -ENODEV;
1229 	}
1230 
1231 	/*
1232 	 * Next, get the DCR property and attempt to map it so that we
1233 	 * can probe the controller.
1234 	 */
1235 
1236 	status = ppc4xx_edac_map_dcrs(np, &dcr_host);
1237 
1238 	if (status)
1239 		return status;
1240 
1241 	/*
1242 	 * First determine whether ECC is enabled at all. If not,
1243 	 * there is no useful checking or monitoring that can be done
1244 	 * for this controller.
1245 	 */
1246 
1247 	mcopt1 = mfsdram(&dcr_host, SDRAM_MCOPT1);
1248 	memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);
1249 
1250 	if (memcheck == SDRAM_MCOPT1_MCHK_NON) {
1251 		ppc4xx_edac_printk(KERN_INFO, "%pOF: No ECC memory detected or "
1252 				   "ECC is disabled.\n", np);
1253 		status = -ENODEV;
1254 		goto done;
1255 	}
1256 
1257 	/*
1258 	 * At this point, we know ECC is enabled, allocate an EDAC
1259 	 * controller instance and perform the appropriate
1260 	 * initialization.
1261 	 */
1262 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
1263 	layers[0].size = ppc4xx_edac_nr_csrows;
1264 	layers[0].is_virt_csrow = true;
1265 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
1266 	layers[1].size = ppc4xx_edac_nr_chans;
1267 	layers[1].is_virt_csrow = false;
1268 	mci = edac_mc_alloc(ppc4xx_edac_instance, ARRAY_SIZE(layers), layers,
1269 			    sizeof(struct ppc4xx_edac_pdata));
1270 	if (mci == NULL) {
1271 		ppc4xx_edac_printk(KERN_ERR, "%pOF: "
1272 				   "Failed to allocate EDAC MC instance!\n",
1273 				   np);
1274 		status = -ENOMEM;
1275 		goto done;
1276 	}
1277 
1278 	status = ppc4xx_edac_mc_init(mci, op, &dcr_host, mcopt1);
1279 
1280 	if (status) {
1281 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1282 				      "Failed to initialize instance!\n");
1283 		goto fail;
1284 	}
1285 
1286 	/*
1287 	 * We have a valid, initialized EDAC instance bound to the
1288 	 * controller. Attempt to register it with the EDAC subsystem
1289 	 * and, if necessary, register interrupts.
1290 	 */
1291 
1292 	if (edac_mc_add_mc(mci)) {
1293 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1294 				      "Failed to add instance!\n");
1295 		status = -ENODEV;
1296 		goto fail;
1297 	}
1298 
1299 	if (edac_op_state == EDAC_OPSTATE_INT) {
1300 		status = ppc4xx_edac_register_irq(op, mci);
1301 
1302 		if (status)
1303 			goto fail1;
1304 	}
1305 
1306 	ppc4xx_edac_instance++;
1307 
1308 	return 0;
1309 
1310  fail1:
1311 	edac_mc_del_mc(mci->pdev);
1312 
1313  fail:
1314 	edac_mc_free(mci);
1315 
1316  done:
1317 	return status;
1318 }
1319 
1320 /**
1321  * ppc4xx_edac_remove - unbind driver from controller
1322  * @op: A pointer to the OpenFirmware device tree node associated
1323  *      with the controller this EDAC instance is to be unbound/removed
1324  *      from.
1325  *
1326  * This routine unbinds the EDAC memory controller instance associated
1327  * with the specified ibm,sdram-4xx-ddr2 controller described by the
1328  * OpenFirmware device tree node passed as a parameter.
1329  *
1330  * Unconditionally returns 0.
1331  */
1332 static int
1333 ppc4xx_edac_remove(struct platform_device *op)
1334 {
1335 	struct mem_ctl_info *mci = dev_get_drvdata(&op->dev);
1336 	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
1337 
1338 	if (edac_op_state == EDAC_OPSTATE_INT) {
1339 		free_irq(pdata->irqs.sec, mci);
1340 		free_irq(pdata->irqs.ded, mci);
1341 	}
1342 
1343 	dcr_unmap(pdata->dcr_host, SDRAM_DCR_RESOURCE_LEN);
1344 
1345 	edac_mc_del_mc(mci->pdev);
1346 	edac_mc_free(mci);
1347 
1348 	return 0;
1349 }
1350 
1351 /**
1352  * ppc4xx_edac_opstate_init - initialize EDAC reporting method
1353  *
1354  * This routine ensures that the EDAC memory controller reporting
1355  * method is mapped to a sane value as the EDAC core defines the value
1356  * to EDAC_OPSTATE_INVAL by default. We don't call the global
1357  * opstate_init as that defaults to polling and we want interrupt as
1358  * the default.
1359  */
1360 static inline void __init
1361 ppc4xx_edac_opstate_init(void)
1362 {
1363 	switch (edac_op_state) {
1364 	case EDAC_OPSTATE_POLL:
1365 	case EDAC_OPSTATE_INT:
1366 		break;
1367 	default:
1368 		edac_op_state = EDAC_OPSTATE_INT;
1369 		break;
1370 	}
1371 
1372 	ppc4xx_edac_printk(KERN_INFO, "Reporting type: %s\n",
1373 			   ((edac_op_state == EDAC_OPSTATE_POLL) ?
1374 			    EDAC_OPSTATE_POLL_STR :
1375 			    ((edac_op_state == EDAC_OPSTATE_INT) ?
1376 			     EDAC_OPSTATE_INT_STR :
1377 			     EDAC_OPSTATE_UNKNOWN_STR)));
1378 }
1379 
1380 static struct platform_driver ppc4xx_edac_driver = {
1381 	.probe			= ppc4xx_edac_probe,
1382 	.remove			= ppc4xx_edac_remove,
1383 	.driver = {
1384 		.name = PPC4XX_EDAC_MODULE_NAME,
1385 		.of_match_table = ppc4xx_edac_match,
1386 	},
1387 };
1388 
1389 /**
1390  * ppc4xx_edac_init - driver/module insertion entry point
1391  *
1392  * This routine is the driver/module insertion entry point. It
1393  * initializes the EDAC memory controller reporting state and
1394  * registers the driver as an OpenFirmware device tree platform
1395  * driver.
1396  */
1397 static int __init
1398 ppc4xx_edac_init(void)
1399 {
1400 	ppc4xx_edac_printk(KERN_INFO, PPC4XX_EDAC_MODULE_REVISION "\n");
1401 
1402 	ppc4xx_edac_opstate_init();
1403 
1404 	return platform_driver_register(&ppc4xx_edac_driver);
1405 }
1406 
1407 /**
1408  * ppc4xx_edac_exit - driver/module removal entry point
1409  *
1410  * This routine is the driver/module removal entry point. It
1411  * unregisters the driver as an OpenFirmware device tree platform
1412  * driver.
1413  */
1414 static void __exit
1415 ppc4xx_edac_exit(void)
1416 {
1417 	platform_driver_unregister(&ppc4xx_edac_driver);
1418 }
1419 
1420 module_init(ppc4xx_edac_init);
1421 module_exit(ppc4xx_edac_exit);
1422 
1423 MODULE_LICENSE("GPL v2");
1424 MODULE_AUTHOR("Grant Erickson <gerickson@nuovations.com>");
1425 MODULE_DESCRIPTION("EDAC MC Driver for the PPC4xx IBM DDR2 Memory Controller");
1426 module_param(edac_op_state, int, 0444);
1427 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting State: "
1428 		 "0=" EDAC_OPSTATE_POLL_STR ", 2=" EDAC_OPSTATE_INT_STR);
1429