• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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_platform.h>
15 #include <linux/types.h>
16 
17 #include <asm/dcr.h>
18 
19 #include "edac_module.h"
20 #include "ppc4xx_edac.h"
21 
22 /*
23  * This file implements a driver for monitoring and handling events
24  * associated with the IMB DDR2 ECC controller found in the AMCC/IBM
25  * 405EX[r], 440SP, 440SPe, 460EX, 460GT and 460SX.
26  *
27  * As realized in the 405EX[r], this controller features:
28  *
29  *   - Support for registered- and non-registered DDR1 and DDR2 memory.
30  *   - 32-bit or 16-bit memory interface with optional ECC.
31  *
32  *     o ECC support includes:
33  *
34  *       - 4-bit SEC/DED
35  *       - Aligned-nibble error detect
36  *       - Bypass mode
37  *
38  *   - Two (2) memory banks/ranks.
39  *   - Up to 1 GiB per bank/rank in 32-bit mode and up to 512 MiB per
40  *     bank/rank in 16-bit mode.
41  *
42  * As realized in the 440SP and 440SPe, this controller changes/adds:
43  *
44  *   - 64-bit or 32-bit memory interface with optional ECC.
45  *
46  *     o ECC support includes:
47  *
48  *       - 8-bit SEC/DED
49  *       - Aligned-nibble error detect
50  *       - Bypass mode
51  *
52  *   - Up to 4 GiB per bank/rank in 64-bit mode and up to 2 GiB
53  *     per bank/rank in 32-bit mode.
54  *
55  * As realized in the 460EX and 460GT, this controller changes/adds:
56  *
57  *   - 64-bit or 32-bit memory interface with optional ECC.
58  *
59  *     o ECC support includes:
60  *
61  *       - 8-bit SEC/DED
62  *       - Aligned-nibble error detect
63  *       - Bypass mode
64  *
65  *   - Four (4) memory banks/ranks.
66  *   - Up to 16 GiB per bank/rank in 64-bit mode and up to 8 GiB
67  *     per bank/rank in 32-bit mode.
68  *
69  * At present, this driver has ONLY been tested against the controller
70  * realization in the 405EX[r] on the AMCC Kilauea and Haleakala
71  * boards (256 MiB w/o ECC memory soldered onto the board) and a
72  * proprietary board based on those designs (128 MiB ECC memory, also
73  * soldered onto the board).
74  *
75  * Dynamic feature detection and handling needs to be added for the
76  * other realizations of this controller listed above.
77  *
78  * Eventually, this driver will likely be adapted to the above variant
79  * realizations of this controller as well as broken apart to handle
80  * the other known ECC-capable controllers prevalent in other 4xx
81  * processors:
82  *
83  *   - IBM SDRAM (405GP, 405CR and 405EP) "ibm,sdram-4xx"
84  *   - IBM DDR1 (440GP, 440GX, 440EP and 440GR) "ibm,sdram-4xx-ddr"
85  *   - Denali DDR1/DDR2 (440EPX and 440GRX) "denali,sdram-4xx-ddr2"
86  *
87  * For this controller, unfortunately, correctable errors report
88  * nothing more than the beat/cycle and byte/lane the correction
89  * occurred on and the check bit group that covered the error.
90  *
91  * In contrast, uncorrectable errors also report the failing address,
92  * the bus master and the transaction direction (i.e. read or write)
93  *
94  * Regardless of whether the error is a CE or a UE, we report the
95  * following pieces of information in the driver-unique message to the
96  * EDAC subsystem:
97  *
98  *   - Device tree path
99  *   - Bank(s)
100  *   - Check bit error group
101  *   - Beat(s)/lane(s)
102  */
103 
104 /* Preprocessor Definitions */
105 
106 #define EDAC_OPSTATE_INT_STR		"interrupt"
107 #define EDAC_OPSTATE_POLL_STR		"polled"
108 #define EDAC_OPSTATE_UNKNOWN_STR	"unknown"
109 
110 #define PPC4XX_EDAC_MODULE_NAME		"ppc4xx_edac"
111 #define PPC4XX_EDAC_MODULE_REVISION	"v1.0.0"
112 
113 #define PPC4XX_EDAC_MESSAGE_SIZE	256
114 
115 /*
116  * Kernel logging without an EDAC instance
117  */
118 #define ppc4xx_edac_printk(level, fmt, arg...) \
119 	edac_printk(level, "PPC4xx MC", fmt, ##arg)
120 
121 /*
122  * Kernel logging with an EDAC instance
123  */
124 #define ppc4xx_edac_mc_printk(level, mci, fmt, arg...) \
125 	edac_mc_chipset_printk(mci, level, "PPC4xx", fmt, ##arg)
126 
127 /*
128  * Macros to convert bank configuration size enumerations into MiB and
129  * page values.
130  */
131 #define SDRAM_MBCF_SZ_MiB_MIN		4
132 #define SDRAM_MBCF_SZ_TO_MiB(n)		(SDRAM_MBCF_SZ_MiB_MIN \
133 					 << (SDRAM_MBCF_SZ_DECODE(n)))
134 #define SDRAM_MBCF_SZ_TO_PAGES(n)	(SDRAM_MBCF_SZ_MiB_MIN \
135 					 << (20 - PAGE_SHIFT + \
136 					     SDRAM_MBCF_SZ_DECODE(n)))
137 
138 /*
139  * The ibm,sdram-4xx-ddr2 Device Control Registers (DCRs) are
140  * indirectly accessed and have a base and length defined by the
141  * device tree. The base can be anything; however, we expect the
142  * length to be precisely two registers, the first for the address
143  * window and the second for the data window.
144  */
145 #define SDRAM_DCR_RESOURCE_LEN		2
146 #define SDRAM_DCR_ADDR_OFFSET		0
147 #define SDRAM_DCR_DATA_OFFSET		1
148 
149 /*
150  * Device tree interrupt indices
151  */
152 #define INTMAP_ECCDED_INDEX		0	/* Double-bit Error Detect */
153 #define INTMAP_ECCSEC_INDEX		1	/* Single-bit Error Correct */
154 
155 /* Type Definitions */
156 
157 /*
158  * PPC4xx SDRAM memory controller private instance data
159  */
160 struct ppc4xx_edac_pdata {
161 	dcr_host_t dcr_host;	/* Indirect DCR address/data window mapping */
162 	struct {
163 		int sec;	/* Single-bit correctable error IRQ assigned */
164 		int ded;	/* Double-bit detectable error IRQ assigned */
165 	} irqs;
166 };
167 
168 /*
169  * Various status data gathered and manipulated when checking and
170  * reporting ECC status.
171  */
172 struct ppc4xx_ecc_status {
173 	u32 ecces;
174 	u32 besr;
175 	u32 bearh;
176 	u32 bearl;
177 	u32 wmirq;
178 };
179 
180 /* Function Prototypes */
181 
182 static int ppc4xx_edac_probe(struct platform_device *device);
183 static int ppc4xx_edac_remove(struct platform_device *device);
184 
185 /* Global Variables */
186 
187 /*
188  * Device tree node type and compatible tuples this driver can match
189  * on.
190  */
191 static const struct of_device_id ppc4xx_edac_match[] = {
192 	{
193 		.compatible	= "ibm,sdram-4xx-ddr2"
194 	},
195 	{ }
196 };
197 MODULE_DEVICE_TABLE(of, ppc4xx_edac_match);
198 
199 static struct platform_driver ppc4xx_edac_driver = {
200 	.probe			= ppc4xx_edac_probe,
201 	.remove			= ppc4xx_edac_remove,
202 	.driver = {
203 		.name = PPC4XX_EDAC_MODULE_NAME,
204 		.of_match_table = ppc4xx_edac_match,
205 	},
206 };
207 
208 /*
209  * TODO: The row and channel parameters likely need to be dynamically
210  * set based on the aforementioned variant controller realizations.
211  */
212 static const unsigned ppc4xx_edac_nr_csrows = 2;
213 static const unsigned ppc4xx_edac_nr_chans = 1;
214 
215 /*
216  * Strings associated with PLB master IDs capable of being posted in
217  * SDRAM_BESR or SDRAM_WMIRQ on uncorrectable ECC errors.
218  */
219 static const char * const ppc4xx_plb_masters[9] = {
220 	[SDRAM_PLB_M0ID_ICU]	= "ICU",
221 	[SDRAM_PLB_M0ID_PCIE0]	= "PCI-E 0",
222 	[SDRAM_PLB_M0ID_PCIE1]	= "PCI-E 1",
223 	[SDRAM_PLB_M0ID_DMA]	= "DMA",
224 	[SDRAM_PLB_M0ID_DCU]	= "DCU",
225 	[SDRAM_PLB_M0ID_OPB]	= "OPB",
226 	[SDRAM_PLB_M0ID_MAL]	= "MAL",
227 	[SDRAM_PLB_M0ID_SEC]	= "SEC",
228 	[SDRAM_PLB_M0ID_AHB]	= "AHB"
229 };
230 
231 /**
232  * mfsdram - read and return controller register data
233  * @dcr_host: A pointer to the DCR mapping.
234  * @idcr_n: The indirect DCR register to read.
235  *
236  * This routine reads and returns the data associated with the
237  * controller's specified indirect DCR register.
238  *
239  * Returns the read data.
240  */
241 static inline u32
mfsdram(const dcr_host_t * dcr_host,unsigned int idcr_n)242 mfsdram(const dcr_host_t *dcr_host, unsigned int idcr_n)
243 {
244 	return __mfdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
245 			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
246 			idcr_n);
247 }
248 
249 /**
250  * mtsdram - write controller register data
251  * @dcr_host: A pointer to the DCR mapping.
252  * @idcr_n: The indirect DCR register to write.
253  * @value: The data to write.
254  *
255  * This routine writes the provided data to the controller's specified
256  * indirect DCR register.
257  */
258 static inline void
mtsdram(const dcr_host_t * dcr_host,unsigned int idcr_n,u32 value)259 mtsdram(const dcr_host_t *dcr_host, unsigned int idcr_n, u32 value)
260 {
261 	return __mtdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
262 			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
263 			idcr_n,
264 			value);
265 }
266 
267 /**
268  * ppc4xx_edac_check_bank_error - check a bank for an ECC bank error
269  * @status: A pointer to the ECC status structure to check for an
270  *          ECC bank error.
271  * @bank: The bank to check for an ECC error.
272  *
273  * This routine determines whether the specified bank has an ECC
274  * error.
275  *
276  * Returns true if the specified bank has an ECC error; otherwise,
277  * false.
278  */
279 static bool
ppc4xx_edac_check_bank_error(const struct ppc4xx_ecc_status * status,unsigned int bank)280 ppc4xx_edac_check_bank_error(const struct ppc4xx_ecc_status *status,
281 			     unsigned int bank)
282 {
283 	switch (bank) {
284 	case 0:
285 		return status->ecces & SDRAM_ECCES_BK0ER;
286 	case 1:
287 		return status->ecces & SDRAM_ECCES_BK1ER;
288 	default:
289 		return false;
290 	}
291 }
292 
293 /**
294  * ppc4xx_edac_generate_bank_message - generate interpretted bank status message
295  * @mci: A pointer to the EDAC memory controller instance associated
296  *       with the bank message being generated.
297  * @status: A pointer to the ECC status structure to generate the
298  *          message from.
299  * @buffer: A pointer to the buffer in which to generate the
300  *          message.
301  * @size: The size, in bytes, of space available in buffer.
302  *
303  * This routine generates to the provided buffer the portion of the
304  * driver-unique report message associated with the ECCESS[BKNER]
305  * field of the specified ECC status.
306  *
307  * Returns the number of characters generated on success; otherwise, <
308  * 0 on error.
309  */
310 static int
ppc4xx_edac_generate_bank_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)311 ppc4xx_edac_generate_bank_message(const struct mem_ctl_info *mci,
312 				  const struct ppc4xx_ecc_status *status,
313 				  char *buffer,
314 				  size_t size)
315 {
316 	int n, total = 0;
317 	unsigned int row, rows;
318 
319 	n = snprintf(buffer, size, "%s: Banks: ", mci->dev_name);
320 
321 	if (n < 0 || n >= size)
322 		goto fail;
323 
324 	buffer += n;
325 	size -= n;
326 	total += n;
327 
328 	for (rows = 0, row = 0; row < mci->nr_csrows; row++) {
329 		if (ppc4xx_edac_check_bank_error(status, row)) {
330 			n = snprintf(buffer, size, "%s%u",
331 					(rows++ ? ", " : ""), row);
332 
333 			if (n < 0 || n >= size)
334 				goto fail;
335 
336 			buffer += n;
337 			size -= n;
338 			total += n;
339 		}
340 	}
341 
342 	n = snprintf(buffer, size, "%s; ", rows ? "" : "None");
343 
344 	if (n < 0 || n >= size)
345 		goto fail;
346 
347 	buffer += n;
348 	size -= n;
349 	total += n;
350 
351  fail:
352 	return total;
353 }
354 
355 /**
356  * ppc4xx_edac_generate_checkbit_message - generate interpretted checkbit message
357  * @mci: A pointer to the EDAC memory controller instance associated
358  *       with the checkbit message being generated.
359  * @status: A pointer to the ECC status structure to generate the
360  *          message from.
361  * @buffer: A pointer to the buffer in which to generate the
362  *          message.
363  * @size: The size, in bytes, of space available in buffer.
364  *
365  * This routine generates to the provided buffer the portion of the
366  * driver-unique report message associated with the ECCESS[CKBER]
367  * field of the specified ECC status.
368  *
369  * Returns the number of characters generated on success; otherwise, <
370  * 0 on error.
371  */
372 static int
ppc4xx_edac_generate_checkbit_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)373 ppc4xx_edac_generate_checkbit_message(const struct mem_ctl_info *mci,
374 				      const struct ppc4xx_ecc_status *status,
375 				      char *buffer,
376 				      size_t size)
377 {
378 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
379 	const char *ckber = NULL;
380 
381 	switch (status->ecces & SDRAM_ECCES_CKBER_MASK) {
382 	case SDRAM_ECCES_CKBER_NONE:
383 		ckber = "None";
384 		break;
385 	case SDRAM_ECCES_CKBER_32_ECC_0_3:
386 		ckber = "ECC0:3";
387 		break;
388 	case SDRAM_ECCES_CKBER_32_ECC_4_8:
389 		switch (mfsdram(&pdata->dcr_host, SDRAM_MCOPT1) &
390 			SDRAM_MCOPT1_WDTH_MASK) {
391 		case SDRAM_MCOPT1_WDTH_16:
392 			ckber = "ECC0:3";
393 			break;
394 		case SDRAM_MCOPT1_WDTH_32:
395 			ckber = "ECC4:8";
396 			break;
397 		default:
398 			ckber = "Unknown";
399 			break;
400 		}
401 		break;
402 	case SDRAM_ECCES_CKBER_32_ECC_0_8:
403 		ckber = "ECC0:8";
404 		break;
405 	default:
406 		ckber = "Unknown";
407 		break;
408 	}
409 
410 	return snprintf(buffer, size, "Checkbit Error: %s", ckber);
411 }
412 
413 /**
414  * ppc4xx_edac_generate_lane_message - generate interpretted byte lane message
415  * @mci: A pointer to the EDAC memory controller instance associated
416  *       with the byte lane message being generated.
417  * @status: A pointer to the ECC status structure to generate the
418  *          message from.
419  * @buffer: A pointer to the buffer in which to generate the
420  *          message.
421  * @size: The size, in bytes, of space available in buffer.
422  *
423  * This routine generates to the provided buffer the portion of the
424  * driver-unique report message associated with the ECCESS[BNCE]
425  * field of the specified ECC status.
426  *
427  * Returns the number of characters generated on success; otherwise, <
428  * 0 on error.
429  */
430 static int
ppc4xx_edac_generate_lane_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)431 ppc4xx_edac_generate_lane_message(const struct mem_ctl_info *mci,
432 				  const struct ppc4xx_ecc_status *status,
433 				  char *buffer,
434 				  size_t size)
435 {
436 	int n, total = 0;
437 	unsigned int lane, lanes;
438 	const unsigned int first_lane = 0;
439 	const unsigned int lane_count = 16;
440 
441 	n = snprintf(buffer, size, "; Byte Lane Errors: ");
442 
443 	if (n < 0 || n >= size)
444 		goto fail;
445 
446 	buffer += n;
447 	size -= n;
448 	total += n;
449 
450 	for (lanes = 0, lane = first_lane; lane < lane_count; lane++) {
451 		if ((status->ecces & SDRAM_ECCES_BNCE_ENCODE(lane)) != 0) {
452 			n = snprintf(buffer, size,
453 				     "%s%u",
454 				     (lanes++ ? ", " : ""), lane);
455 
456 			if (n < 0 || n >= size)
457 				goto fail;
458 
459 			buffer += n;
460 			size -= n;
461 			total += n;
462 		}
463 	}
464 
465 	n = snprintf(buffer, size, "%s; ", lanes ? "" : "None");
466 
467 	if (n < 0 || n >= size)
468 		goto fail;
469 
470 	buffer += n;
471 	size -= n;
472 	total += n;
473 
474  fail:
475 	return total;
476 }
477 
478 /**
479  * ppc4xx_edac_generate_ecc_message - generate interpretted ECC status message
480  * @mci: A pointer to the EDAC memory controller instance associated
481  *       with the ECCES message being generated.
482  * @status: A pointer to the ECC status structure to generate the
483  *          message from.
484  * @buffer: A pointer to the buffer in which to generate the
485  *          message.
486  * @size: The size, in bytes, of space available in buffer.
487  *
488  * This routine generates to the provided buffer the portion of the
489  * driver-unique report message associated with the ECCESS register of
490  * the specified ECC status.
491  *
492  * Returns the number of characters generated on success; otherwise, <
493  * 0 on error.
494  */
495 static int
ppc4xx_edac_generate_ecc_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)496 ppc4xx_edac_generate_ecc_message(const struct mem_ctl_info *mci,
497 				 const struct ppc4xx_ecc_status *status,
498 				 char *buffer,
499 				 size_t size)
500 {
501 	int n, total = 0;
502 
503 	n = ppc4xx_edac_generate_bank_message(mci, status, buffer, size);
504 
505 	if (n < 0 || n >= size)
506 		goto fail;
507 
508 	buffer += n;
509 	size -= n;
510 	total += n;
511 
512 	n = ppc4xx_edac_generate_checkbit_message(mci, status, buffer, size);
513 
514 	if (n < 0 || n >= size)
515 		goto fail;
516 
517 	buffer += n;
518 	size -= n;
519 	total += n;
520 
521 	n = ppc4xx_edac_generate_lane_message(mci, status, buffer, size);
522 
523 	if (n < 0 || n >= size)
524 		goto fail;
525 
526 	buffer += n;
527 	size -= n;
528 	total += n;
529 
530  fail:
531 	return total;
532 }
533 
534 /**
535  * ppc4xx_edac_generate_plb_message - generate interpretted PLB status message
536  * @mci: A pointer to the EDAC memory controller instance associated
537  *       with the PLB message being generated.
538  * @status: A pointer to the ECC status structure to generate the
539  *          message from.
540  * @buffer: A pointer to the buffer in which to generate the
541  *          message.
542  * @size: The size, in bytes, of space available in buffer.
543  *
544  * This routine generates to the provided buffer the portion of the
545  * driver-unique report message associated with the PLB-related BESR
546  * and/or WMIRQ registers of the specified ECC status.
547  *
548  * Returns the number of characters generated on success; otherwise, <
549  * 0 on error.
550  */
551 static int
ppc4xx_edac_generate_plb_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)552 ppc4xx_edac_generate_plb_message(const struct mem_ctl_info *mci,
553 				 const struct ppc4xx_ecc_status *status,
554 				 char *buffer,
555 				 size_t size)
556 {
557 	unsigned int master;
558 	bool read;
559 
560 	if ((status->besr & SDRAM_BESR_MASK) == 0)
561 		return 0;
562 
563 	if ((status->besr & SDRAM_BESR_M0ET_MASK) == SDRAM_BESR_M0ET_NONE)
564 		return 0;
565 
566 	read = ((status->besr & SDRAM_BESR_M0RW_MASK) == SDRAM_BESR_M0RW_READ);
567 
568 	master = SDRAM_BESR_M0ID_DECODE(status->besr);
569 
570 	return snprintf(buffer, size,
571 			"%s error w/ PLB master %u \"%s\"; ",
572 			(read ? "Read" : "Write"),
573 			master,
574 			(((master >= SDRAM_PLB_M0ID_FIRST) &&
575 			  (master <= SDRAM_PLB_M0ID_LAST)) ?
576 			 ppc4xx_plb_masters[master] : "UNKNOWN"));
577 }
578 
579 /**
580  * ppc4xx_edac_generate_message - generate interpretted status message
581  * @mci: A pointer to the EDAC memory controller instance associated
582  *       with the driver-unique message being generated.
583  * @status: A pointer to the ECC status structure to generate the
584  *          message from.
585  * @buffer: A pointer to the buffer in which to generate the
586  *          message.
587  * @size: The size, in bytes, of space available in buffer.
588  *
589  * This routine generates to the provided buffer the driver-unique
590  * EDAC report message from the specified ECC status.
591  */
592 static void
ppc4xx_edac_generate_message(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status,char * buffer,size_t size)593 ppc4xx_edac_generate_message(const struct mem_ctl_info *mci,
594 			     const struct ppc4xx_ecc_status *status,
595 			     char *buffer,
596 			     size_t size)
597 {
598 	int n;
599 
600 	if (buffer == NULL || size == 0)
601 		return;
602 
603 	n = ppc4xx_edac_generate_ecc_message(mci, status, buffer, size);
604 
605 	if (n < 0 || n >= size)
606 		return;
607 
608 	buffer += n;
609 	size -= n;
610 
611 	ppc4xx_edac_generate_plb_message(mci, status, buffer, size);
612 }
613 
614 #ifdef DEBUG
615 /**
616  * ppc4xx_ecc_dump_status - dump controller ECC status registers
617  * @mci: A pointer to the EDAC memory controller instance
618  *       associated with the status being dumped.
619  * @status: A pointer to the ECC status structure to generate the
620  *          dump from.
621  *
622  * This routine dumps to the kernel log buffer the raw and
623  * interpretted specified ECC status.
624  */
625 static void
ppc4xx_ecc_dump_status(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status)626 ppc4xx_ecc_dump_status(const struct mem_ctl_info *mci,
627 		       const struct ppc4xx_ecc_status *status)
628 {
629 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
630 
631 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
632 
633 	ppc4xx_edac_mc_printk(KERN_INFO, mci,
634 			      "\n"
635 			      "\tECCES: 0x%08x\n"
636 			      "\tWMIRQ: 0x%08x\n"
637 			      "\tBESR:  0x%08x\n"
638 			      "\tBEAR:  0x%08x%08x\n"
639 			      "\t%s\n",
640 			      status->ecces,
641 			      status->wmirq,
642 			      status->besr,
643 			      status->bearh,
644 			      status->bearl,
645 			      message);
646 }
647 #endif /* DEBUG */
648 
649 /**
650  * ppc4xx_ecc_get_status - get controller ECC status
651  * @mci: A pointer to the EDAC memory controller instance
652  *       associated with the status being retrieved.
653  * @status: A pointer to the ECC status structure to populate the
654  *          ECC status with.
655  *
656  * This routine reads and masks, as appropriate, all the relevant
657  * status registers that deal with ibm,sdram-4xx-ddr2 ECC errors.
658  * While we read all of them, for correctable errors, we only expect
659  * to deal with ECCES. For uncorrectable errors, we expect to deal
660  * with all of them.
661  */
662 static void
ppc4xx_ecc_get_status(const struct mem_ctl_info * mci,struct ppc4xx_ecc_status * status)663 ppc4xx_ecc_get_status(const struct mem_ctl_info *mci,
664 		      struct ppc4xx_ecc_status *status)
665 {
666 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
667 	const dcr_host_t *dcr_host = &pdata->dcr_host;
668 
669 	status->ecces = mfsdram(dcr_host, SDRAM_ECCES) & SDRAM_ECCES_MASK;
670 	status->wmirq = mfsdram(dcr_host, SDRAM_WMIRQ) & SDRAM_WMIRQ_MASK;
671 	status->besr  = mfsdram(dcr_host, SDRAM_BESR)  & SDRAM_BESR_MASK;
672 	status->bearl = mfsdram(dcr_host, SDRAM_BEARL);
673 	status->bearh = mfsdram(dcr_host, SDRAM_BEARH);
674 }
675 
676 /**
677  * ppc4xx_ecc_clear_status - clear controller ECC status
678  * @mci: A pointer to the EDAC memory controller instance
679  *       associated with the status being cleared.
680  * @status: A pointer to the ECC status structure containing the
681  *          values to write to clear the ECC status.
682  *
683  * This routine clears--by writing the masked (as appropriate) status
684  * values back to--the status registers that deal with
685  * ibm,sdram-4xx-ddr2 ECC errors.
686  */
687 static void
ppc4xx_ecc_clear_status(const struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status)688 ppc4xx_ecc_clear_status(const struct mem_ctl_info *mci,
689 			const struct ppc4xx_ecc_status *status)
690 {
691 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
692 	const dcr_host_t *dcr_host = &pdata->dcr_host;
693 
694 	mtsdram(dcr_host, SDRAM_ECCES,	status->ecces & SDRAM_ECCES_MASK);
695 	mtsdram(dcr_host, SDRAM_WMIRQ,	status->wmirq & SDRAM_WMIRQ_MASK);
696 	mtsdram(dcr_host, SDRAM_BESR,	status->besr & SDRAM_BESR_MASK);
697 	mtsdram(dcr_host, SDRAM_BEARL,	0);
698 	mtsdram(dcr_host, SDRAM_BEARH,	0);
699 }
700 
701 /**
702  * ppc4xx_edac_handle_ce - handle controller correctable ECC error (CE)
703  * @mci: A pointer to the EDAC memory controller instance
704  *       associated with the correctable error being handled and reported.
705  * @status: A pointer to the ECC status structure associated with
706  *          the correctable error being handled and reported.
707  *
708  * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
709  * correctable error. Per the aforementioned discussion, there's not
710  * enough status available to use the full EDAC correctable error
711  * interface, so we just pass driver-unique message to the "no info"
712  * interface.
713  */
714 static void
ppc4xx_edac_handle_ce(struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status)715 ppc4xx_edac_handle_ce(struct mem_ctl_info *mci,
716 		      const struct ppc4xx_ecc_status *status)
717 {
718 	int row;
719 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
720 
721 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
722 
723 	for (row = 0; row < mci->nr_csrows; row++)
724 		if (ppc4xx_edac_check_bank_error(status, row))
725 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
726 					     0, 0, 0,
727 					     row, 0, -1,
728 					     message, "");
729 }
730 
731 /**
732  * ppc4xx_edac_handle_ue - handle controller uncorrectable ECC error (UE)
733  * @mci: A pointer to the EDAC memory controller instance
734  *       associated with the uncorrectable error being handled and
735  *       reported.
736  * @status: A pointer to the ECC status structure associated with
737  *          the uncorrectable error being handled and reported.
738  *
739  * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
740  * uncorrectable error.
741  */
742 static void
ppc4xx_edac_handle_ue(struct mem_ctl_info * mci,const struct ppc4xx_ecc_status * status)743 ppc4xx_edac_handle_ue(struct mem_ctl_info *mci,
744 		      const struct ppc4xx_ecc_status *status)
745 {
746 	const u64 bear = ((u64)status->bearh << 32 | status->bearl);
747 	const unsigned long page = bear >> PAGE_SHIFT;
748 	const unsigned long offset = bear & ~PAGE_MASK;
749 	int row;
750 	char message[PPC4XX_EDAC_MESSAGE_SIZE];
751 
752 	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));
753 
754 	for (row = 0; row < mci->nr_csrows; row++)
755 		if (ppc4xx_edac_check_bank_error(status, row))
756 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
757 					     page, offset, 0,
758 					     row, 0, -1,
759 					     message, "");
760 }
761 
762 /**
763  * ppc4xx_edac_check - check controller for ECC errors
764  * @mci: A pointer to the EDAC memory controller instance
765  *       associated with the ibm,sdram-4xx-ddr2 controller being
766  *       checked.
767  *
768  * This routine is used to check and post ECC errors and is called by
769  * both the EDAC polling thread and this driver's CE and UE interrupt
770  * handler.
771  */
772 static void
ppc4xx_edac_check(struct mem_ctl_info * mci)773 ppc4xx_edac_check(struct mem_ctl_info *mci)
774 {
775 #ifdef DEBUG
776 	static unsigned int count;
777 #endif
778 	struct ppc4xx_ecc_status status;
779 
780 	ppc4xx_ecc_get_status(mci, &status);
781 
782 #ifdef DEBUG
783 	if (count++ % 30 == 0)
784 		ppc4xx_ecc_dump_status(mci, &status);
785 #endif
786 
787 	if (status.ecces & SDRAM_ECCES_UE)
788 		ppc4xx_edac_handle_ue(mci, &status);
789 
790 	if (status.ecces & SDRAM_ECCES_CE)
791 		ppc4xx_edac_handle_ce(mci, &status);
792 
793 	ppc4xx_ecc_clear_status(mci, &status);
794 }
795 
796 /**
797  * ppc4xx_edac_isr - SEC (CE) and DED (UE) interrupt service routine
798  * @irq:    The virtual interrupt number being serviced.
799  * @dev_id: A pointer to the EDAC memory controller instance
800  *          associated with the interrupt being handled.
801  *
802  * This routine implements the interrupt handler for both correctable
803  * (CE) and uncorrectable (UE) ECC errors for the ibm,sdram-4xx-ddr2
804  * controller. It simply calls through to the same routine used during
805  * polling to check, report and clear the ECC status.
806  *
807  * Unconditionally returns IRQ_HANDLED.
808  */
809 static irqreturn_t
ppc4xx_edac_isr(int irq,void * dev_id)810 ppc4xx_edac_isr(int irq, void *dev_id)
811 {
812 	struct mem_ctl_info *mci = dev_id;
813 
814 	ppc4xx_edac_check(mci);
815 
816 	return IRQ_HANDLED;
817 }
818 
819 /**
820  * ppc4xx_edac_get_dtype - return the controller memory width
821  * @mcopt1: The 32-bit Memory Controller Option 1 register value
822  *          currently set for the controller, from which the width
823  *          is derived.
824  *
825  * This routine returns the EDAC device type width appropriate for the
826  * current controller configuration.
827  *
828  * TODO: This needs to be conditioned dynamically through feature
829  * flags or some such when other controller variants are supported as
830  * the 405EX[r] is 16-/32-bit and the others are 32-/64-bit with the
831  * 16- and 64-bit field definition/value/enumeration (b1) overloaded
832  * among them.
833  *
834  * Returns a device type width enumeration.
835  */
ppc4xx_edac_get_dtype(u32 mcopt1)836 static enum dev_type ppc4xx_edac_get_dtype(u32 mcopt1)
837 {
838 	switch (mcopt1 & SDRAM_MCOPT1_WDTH_MASK) {
839 	case SDRAM_MCOPT1_WDTH_16:
840 		return DEV_X2;
841 	case SDRAM_MCOPT1_WDTH_32:
842 		return DEV_X4;
843 	default:
844 		return DEV_UNKNOWN;
845 	}
846 }
847 
848 /**
849  * ppc4xx_edac_get_mtype - return controller memory type
850  * @mcopt1: The 32-bit Memory Controller Option 1 register value
851  *          currently set for the controller, from which the memory type
852  *          is derived.
853  *
854  * This routine returns the EDAC memory type appropriate for the
855  * current controller configuration.
856  *
857  * Returns a memory type enumeration.
858  */
ppc4xx_edac_get_mtype(u32 mcopt1)859 static enum mem_type ppc4xx_edac_get_mtype(u32 mcopt1)
860 {
861 	bool rden = ((mcopt1 & SDRAM_MCOPT1_RDEN_MASK) == SDRAM_MCOPT1_RDEN);
862 
863 	switch (mcopt1 & SDRAM_MCOPT1_DDR_TYPE_MASK) {
864 	case SDRAM_MCOPT1_DDR2_TYPE:
865 		return rden ? MEM_RDDR2 : MEM_DDR2;
866 	case SDRAM_MCOPT1_DDR1_TYPE:
867 		return rden ? MEM_RDDR : MEM_DDR;
868 	default:
869 		return MEM_UNKNOWN;
870 	}
871 }
872 
873 /**
874  * ppc4xx_edac_init_csrows - initialize driver instance rows
875  * @mci: A pointer to the EDAC memory controller instance
876  *       associated with the ibm,sdram-4xx-ddr2 controller for which
877  *       the csrows (i.e. banks/ranks) are being initialized.
878  * @mcopt1: The 32-bit Memory Controller Option 1 register value
879  *          currently set for the controller, from which bank width
880  *          and memory typ information is derived.
881  *
882  * This routine initializes the virtual "chip select rows" associated
883  * with the EDAC memory controller instance. An ibm,sdram-4xx-ddr2
884  * controller bank/rank is mapped to a row.
885  *
886  * Returns 0 if OK; otherwise, -EINVAL if the memory bank size
887  * configuration cannot be determined.
888  */
ppc4xx_edac_init_csrows(struct mem_ctl_info * mci,u32 mcopt1)889 static int ppc4xx_edac_init_csrows(struct mem_ctl_info *mci, u32 mcopt1)
890 {
891 	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
892 	int status = 0;
893 	enum mem_type mtype;
894 	enum dev_type dtype;
895 	enum edac_type edac_mode;
896 	int row, j;
897 	u32 mbxcf, size, nr_pages;
898 
899 	/* Establish the memory type and width */
900 
901 	mtype = ppc4xx_edac_get_mtype(mcopt1);
902 	dtype = ppc4xx_edac_get_dtype(mcopt1);
903 
904 	/* Establish EDAC mode */
905 
906 	if (mci->edac_cap & EDAC_FLAG_SECDED)
907 		edac_mode = EDAC_SECDED;
908 	else if (mci->edac_cap & EDAC_FLAG_EC)
909 		edac_mode = EDAC_EC;
910 	else
911 		edac_mode = EDAC_NONE;
912 
913 	/*
914 	 * Initialize each chip select row structure which correspond
915 	 * 1:1 with a controller bank/rank.
916 	 */
917 
918 	for (row = 0; row < mci->nr_csrows; row++) {
919 		struct csrow_info *csi = mci->csrows[row];
920 
921 		/*
922 		 * Get the configuration settings for this
923 		 * row/bank/rank and skip disabled banks.
924 		 */
925 
926 		mbxcf = mfsdram(&pdata->dcr_host, SDRAM_MBXCF(row));
927 
928 		if ((mbxcf & SDRAM_MBCF_BE_MASK) != SDRAM_MBCF_BE_ENABLE)
929 			continue;
930 
931 		/* Map the bank configuration size setting to pages. */
932 
933 		size = mbxcf & SDRAM_MBCF_SZ_MASK;
934 
935 		switch (size) {
936 		case SDRAM_MBCF_SZ_4MB:
937 		case SDRAM_MBCF_SZ_8MB:
938 		case SDRAM_MBCF_SZ_16MB:
939 		case SDRAM_MBCF_SZ_32MB:
940 		case SDRAM_MBCF_SZ_64MB:
941 		case SDRAM_MBCF_SZ_128MB:
942 		case SDRAM_MBCF_SZ_256MB:
943 		case SDRAM_MBCF_SZ_512MB:
944 		case SDRAM_MBCF_SZ_1GB:
945 		case SDRAM_MBCF_SZ_2GB:
946 		case SDRAM_MBCF_SZ_4GB:
947 		case SDRAM_MBCF_SZ_8GB:
948 			nr_pages = SDRAM_MBCF_SZ_TO_PAGES(size);
949 			break;
950 		default:
951 			ppc4xx_edac_mc_printk(KERN_ERR, mci,
952 					      "Unrecognized memory bank %d "
953 					      "size 0x%08x\n",
954 					      row, SDRAM_MBCF_SZ_DECODE(size));
955 			status = -EINVAL;
956 			goto done;
957 		}
958 
959 		/*
960 		 * It's unclear exactly what grain should be set to
961 		 * here. The SDRAM_ECCES register allows resolution of
962 		 * an error down to a nibble which would potentially
963 		 * argue for a grain of '1' byte, even though we only
964 		 * know the associated address for uncorrectable
965 		 * errors. This value is not used at present for
966 		 * anything other than error reporting so getting it
967 		 * wrong should be of little consequence. Other
968 		 * possible values would be the PLB width (16), the
969 		 * page size (PAGE_SIZE) or the memory width (2 or 4).
970 		 */
971 		for (j = 0; j < csi->nr_channels; j++) {
972 			struct dimm_info *dimm = csi->channels[j]->dimm;
973 
974 			dimm->nr_pages  = nr_pages / csi->nr_channels;
975 			dimm->grain	= 1;
976 
977 			dimm->mtype	= mtype;
978 			dimm->dtype	= dtype;
979 
980 			dimm->edac_mode	= edac_mode;
981 		}
982 	}
983 
984  done:
985 	return status;
986 }
987 
988 /**
989  * ppc4xx_edac_mc_init - initialize driver instance
990  * @mci: A pointer to the EDAC memory controller instance being
991  *       initialized.
992  * @op: A pointer to the OpenFirmware device tree node associated
993  *      with the controller this EDAC instance is bound to.
994  * @dcr_host: A pointer to the DCR data containing the DCR mapping
995  *            for this controller instance.
996  * @mcopt1: The 32-bit Memory Controller Option 1 register value
997  *          currently set for the controller, from which ECC capabilities
998  *          and scrub mode are derived.
999  *
1000  * This routine performs initialization of the EDAC memory controller
1001  * instance and related driver-private data associated with the
1002  * ibm,sdram-4xx-ddr2 memory controller the instance is bound to.
1003  *
1004  * Returns 0 if OK; otherwise, < 0 on error.
1005  */
ppc4xx_edac_mc_init(struct mem_ctl_info * mci,struct platform_device * op,const dcr_host_t * dcr_host,u32 mcopt1)1006 static int ppc4xx_edac_mc_init(struct mem_ctl_info *mci,
1007 			       struct platform_device *op,
1008 			       const dcr_host_t *dcr_host, u32 mcopt1)
1009 {
1010 	int status = 0;
1011 	const u32 memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);
1012 	struct ppc4xx_edac_pdata *pdata = NULL;
1013 	const struct device_node *np = op->dev.of_node;
1014 
1015 	if (of_match_device(ppc4xx_edac_match, &op->dev) == NULL)
1016 		return -EINVAL;
1017 
1018 	/* Initial driver pointers and private data */
1019 
1020 	mci->pdev		= &op->dev;
1021 
1022 	dev_set_drvdata(mci->pdev, mci);
1023 
1024 	pdata			= mci->pvt_info;
1025 
1026 	pdata->dcr_host		= *dcr_host;
1027 
1028 	/* Initialize controller capabilities and configuration */
1029 
1030 	mci->mtype_cap		= (MEM_FLAG_DDR | MEM_FLAG_RDDR |
1031 				   MEM_FLAG_DDR2 | MEM_FLAG_RDDR2);
1032 
1033 	mci->edac_ctl_cap	= (EDAC_FLAG_NONE |
1034 				   EDAC_FLAG_EC |
1035 				   EDAC_FLAG_SECDED);
1036 
1037 	mci->scrub_cap		= SCRUB_NONE;
1038 	mci->scrub_mode		= SCRUB_NONE;
1039 
1040 	/*
1041 	 * Update the actual capabilites based on the MCOPT1[MCHK]
1042 	 * settings. Scrubbing is only useful if reporting is enabled.
1043 	 */
1044 
1045 	switch (memcheck) {
1046 	case SDRAM_MCOPT1_MCHK_CHK:
1047 		mci->edac_cap	= EDAC_FLAG_EC;
1048 		break;
1049 	case SDRAM_MCOPT1_MCHK_CHK_REP:
1050 		mci->edac_cap	= (EDAC_FLAG_EC | EDAC_FLAG_SECDED);
1051 		mci->scrub_mode	= SCRUB_SW_SRC;
1052 		break;
1053 	default:
1054 		mci->edac_cap	= EDAC_FLAG_NONE;
1055 		break;
1056 	}
1057 
1058 	/* Initialize strings */
1059 
1060 	mci->mod_name		= PPC4XX_EDAC_MODULE_NAME;
1061 	mci->ctl_name		= ppc4xx_edac_match->compatible,
1062 	mci->dev_name		= np->full_name;
1063 
1064 	/* Initialize callbacks */
1065 
1066 	mci->edac_check		= ppc4xx_edac_check;
1067 	mci->ctl_page_to_phys	= NULL;
1068 
1069 	/* Initialize chip select rows */
1070 
1071 	status = ppc4xx_edac_init_csrows(mci, mcopt1);
1072 
1073 	if (status)
1074 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1075 				      "Failed to initialize rows!\n");
1076 
1077 	return status;
1078 }
1079 
1080 /**
1081  * ppc4xx_edac_register_irq - setup and register controller interrupts
1082  * @op: A pointer to the OpenFirmware device tree node associated
1083  *      with the controller this EDAC instance is bound to.
1084  * @mci: A pointer to the EDAC memory controller instance
1085  *       associated with the ibm,sdram-4xx-ddr2 controller for which
1086  *       interrupts are being registered.
1087  *
1088  * This routine parses the correctable (CE) and uncorrectable error (UE)
1089  * interrupts from the device tree node and maps and assigns them to
1090  * the associated EDAC memory controller instance.
1091  *
1092  * Returns 0 if OK; otherwise, -ENODEV if the interrupts could not be
1093  * mapped and assigned.
1094  */
ppc4xx_edac_register_irq(struct platform_device * op,struct mem_ctl_info * mci)1095 static int ppc4xx_edac_register_irq(struct platform_device *op,
1096 				    struct mem_ctl_info *mci)
1097 {
1098 	int status = 0;
1099 	int ded_irq, sec_irq;
1100 	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
1101 	struct device_node *np = op->dev.of_node;
1102 
1103 	ded_irq = irq_of_parse_and_map(np, INTMAP_ECCDED_INDEX);
1104 	sec_irq = irq_of_parse_and_map(np, INTMAP_ECCSEC_INDEX);
1105 
1106 	if (!ded_irq || !sec_irq) {
1107 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1108 				      "Unable to map interrupts.\n");
1109 		status = -ENODEV;
1110 		goto fail;
1111 	}
1112 
1113 	status = request_irq(ded_irq,
1114 			     ppc4xx_edac_isr,
1115 			     0,
1116 			     "[EDAC] MC ECCDED",
1117 			     mci);
1118 
1119 	if (status < 0) {
1120 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1121 				      "Unable to request irq %d for ECC DED",
1122 				      ded_irq);
1123 		status = -ENODEV;
1124 		goto fail1;
1125 	}
1126 
1127 	status = request_irq(sec_irq,
1128 			     ppc4xx_edac_isr,
1129 			     0,
1130 			     "[EDAC] MC ECCSEC",
1131 			     mci);
1132 
1133 	if (status < 0) {
1134 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1135 				      "Unable to request irq %d for ECC SEC",
1136 				      sec_irq);
1137 		status = -ENODEV;
1138 		goto fail2;
1139 	}
1140 
1141 	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCDED irq is %d\n", ded_irq);
1142 	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCSEC irq is %d\n", sec_irq);
1143 
1144 	pdata->irqs.ded = ded_irq;
1145 	pdata->irqs.sec = sec_irq;
1146 
1147 	return 0;
1148 
1149  fail2:
1150 	free_irq(sec_irq, mci);
1151 
1152  fail1:
1153 	free_irq(ded_irq, mci);
1154 
1155  fail:
1156 	return status;
1157 }
1158 
1159 /**
1160  * ppc4xx_edac_map_dcrs - locate and map controller registers
1161  * @np: A pointer to the device tree node containing the DCR
1162  *      resources to map.
1163  * @dcr_host: A pointer to the DCR data to populate with the
1164  *            DCR mapping.
1165  *
1166  * This routine attempts to locate in the device tree and map the DCR
1167  * register resources associated with the controller's indirect DCR
1168  * address and data windows.
1169  *
1170  * Returns 0 if the DCRs were successfully mapped; otherwise, < 0 on
1171  * error.
1172  */
ppc4xx_edac_map_dcrs(const struct device_node * np,dcr_host_t * dcr_host)1173 static int ppc4xx_edac_map_dcrs(const struct device_node *np,
1174 				dcr_host_t *dcr_host)
1175 {
1176 	unsigned int dcr_base, dcr_len;
1177 
1178 	if (np == NULL || dcr_host == NULL)
1179 		return -EINVAL;
1180 
1181 	/* Get the DCR resource extent and sanity check the values. */
1182 
1183 	dcr_base = dcr_resource_start(np, 0);
1184 	dcr_len = dcr_resource_len(np, 0);
1185 
1186 	if (dcr_base == 0 || dcr_len == 0) {
1187 		ppc4xx_edac_printk(KERN_ERR,
1188 				   "Failed to obtain DCR property.\n");
1189 		return -ENODEV;
1190 	}
1191 
1192 	if (dcr_len != SDRAM_DCR_RESOURCE_LEN) {
1193 		ppc4xx_edac_printk(KERN_ERR,
1194 				   "Unexpected DCR length %d, expected %d.\n",
1195 				   dcr_len, SDRAM_DCR_RESOURCE_LEN);
1196 		return -ENODEV;
1197 	}
1198 
1199 	/*  Attempt to map the DCR extent. */
1200 
1201 	*dcr_host = dcr_map(np, dcr_base, dcr_len);
1202 
1203 	if (!DCR_MAP_OK(*dcr_host)) {
1204 		ppc4xx_edac_printk(KERN_INFO, "Failed to map DCRs.\n");
1205 		    return -ENODEV;
1206 	}
1207 
1208 	return 0;
1209 }
1210 
1211 /**
1212  * ppc4xx_edac_probe - check controller and bind driver
1213  * @op: A pointer to the OpenFirmware device tree node associated
1214  *      with the controller being probed for driver binding.
1215  *
1216  * This routine probes a specific ibm,sdram-4xx-ddr2 controller
1217  * instance for binding with the driver.
1218  *
1219  * Returns 0 if the controller instance was successfully bound to the
1220  * driver; otherwise, < 0 on error.
1221  */
ppc4xx_edac_probe(struct platform_device * op)1222 static int ppc4xx_edac_probe(struct platform_device *op)
1223 {
1224 	int status = 0;
1225 	u32 mcopt1, memcheck;
1226 	dcr_host_t dcr_host;
1227 	const struct device_node *np = op->dev.of_node;
1228 	struct mem_ctl_info *mci = NULL;
1229 	struct edac_mc_layer layers[2];
1230 	static int ppc4xx_edac_instance;
1231 
1232 	/*
1233 	 * At this point, we only support the controller realized on
1234 	 * the AMCC PPC 405EX[r]. Reject anything else.
1235 	 */
1236 
1237 	if (!of_device_is_compatible(np, "ibm,sdram-405ex") &&
1238 	    !of_device_is_compatible(np, "ibm,sdram-405exr")) {
1239 		ppc4xx_edac_printk(KERN_NOTICE,
1240 				   "Only the PPC405EX[r] is supported.\n");
1241 		return -ENODEV;
1242 	}
1243 
1244 	/*
1245 	 * Next, get the DCR property and attempt to map it so that we
1246 	 * can probe the controller.
1247 	 */
1248 
1249 	status = ppc4xx_edac_map_dcrs(np, &dcr_host);
1250 
1251 	if (status)
1252 		return status;
1253 
1254 	/*
1255 	 * First determine whether ECC is enabled at all. If not,
1256 	 * there is no useful checking or monitoring that can be done
1257 	 * for this controller.
1258 	 */
1259 
1260 	mcopt1 = mfsdram(&dcr_host, SDRAM_MCOPT1);
1261 	memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);
1262 
1263 	if (memcheck == SDRAM_MCOPT1_MCHK_NON) {
1264 		ppc4xx_edac_printk(KERN_INFO, "%pOF: No ECC memory detected or "
1265 				   "ECC is disabled.\n", np);
1266 		status = -ENODEV;
1267 		goto done;
1268 	}
1269 
1270 	/*
1271 	 * At this point, we know ECC is enabled, allocate an EDAC
1272 	 * controller instance and perform the appropriate
1273 	 * initialization.
1274 	 */
1275 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
1276 	layers[0].size = ppc4xx_edac_nr_csrows;
1277 	layers[0].is_virt_csrow = true;
1278 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
1279 	layers[1].size = ppc4xx_edac_nr_chans;
1280 	layers[1].is_virt_csrow = false;
1281 	mci = edac_mc_alloc(ppc4xx_edac_instance, ARRAY_SIZE(layers), layers,
1282 			    sizeof(struct ppc4xx_edac_pdata));
1283 	if (mci == NULL) {
1284 		ppc4xx_edac_printk(KERN_ERR, "%pOF: "
1285 				   "Failed to allocate EDAC MC instance!\n",
1286 				   np);
1287 		status = -ENOMEM;
1288 		goto done;
1289 	}
1290 
1291 	status = ppc4xx_edac_mc_init(mci, op, &dcr_host, mcopt1);
1292 
1293 	if (status) {
1294 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1295 				      "Failed to initialize instance!\n");
1296 		goto fail;
1297 	}
1298 
1299 	/*
1300 	 * We have a valid, initialized EDAC instance bound to the
1301 	 * controller. Attempt to register it with the EDAC subsystem
1302 	 * and, if necessary, register interrupts.
1303 	 */
1304 
1305 	if (edac_mc_add_mc(mci)) {
1306 		ppc4xx_edac_mc_printk(KERN_ERR, mci,
1307 				      "Failed to add instance!\n");
1308 		status = -ENODEV;
1309 		goto fail;
1310 	}
1311 
1312 	if (edac_op_state == EDAC_OPSTATE_INT) {
1313 		status = ppc4xx_edac_register_irq(op, mci);
1314 
1315 		if (status)
1316 			goto fail1;
1317 	}
1318 
1319 	ppc4xx_edac_instance++;
1320 
1321 	return 0;
1322 
1323  fail1:
1324 	edac_mc_del_mc(mci->pdev);
1325 
1326  fail:
1327 	edac_mc_free(mci);
1328 
1329  done:
1330 	return status;
1331 }
1332 
1333 /**
1334  * ppc4xx_edac_remove - unbind driver from controller
1335  * @op: A pointer to the OpenFirmware device tree node associated
1336  *      with the controller this EDAC instance is to be unbound/removed
1337  *      from.
1338  *
1339  * This routine unbinds the EDAC memory controller instance associated
1340  * with the specified ibm,sdram-4xx-ddr2 controller described by the
1341  * OpenFirmware device tree node passed as a parameter.
1342  *
1343  * Unconditionally returns 0.
1344  */
1345 static int
ppc4xx_edac_remove(struct platform_device * op)1346 ppc4xx_edac_remove(struct platform_device *op)
1347 {
1348 	struct mem_ctl_info *mci = dev_get_drvdata(&op->dev);
1349 	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
1350 
1351 	if (edac_op_state == EDAC_OPSTATE_INT) {
1352 		free_irq(pdata->irqs.sec, mci);
1353 		free_irq(pdata->irqs.ded, mci);
1354 	}
1355 
1356 	dcr_unmap(pdata->dcr_host, SDRAM_DCR_RESOURCE_LEN);
1357 
1358 	edac_mc_del_mc(mci->pdev);
1359 	edac_mc_free(mci);
1360 
1361 	return 0;
1362 }
1363 
1364 /**
1365  * ppc4xx_edac_opstate_init - initialize EDAC reporting method
1366  *
1367  * This routine ensures that the EDAC memory controller reporting
1368  * method is mapped to a sane value as the EDAC core defines the value
1369  * to EDAC_OPSTATE_INVAL by default. We don't call the global
1370  * opstate_init as that defaults to polling and we want interrupt as
1371  * the default.
1372  */
1373 static inline void __init
ppc4xx_edac_opstate_init(void)1374 ppc4xx_edac_opstate_init(void)
1375 {
1376 	switch (edac_op_state) {
1377 	case EDAC_OPSTATE_POLL:
1378 	case EDAC_OPSTATE_INT:
1379 		break;
1380 	default:
1381 		edac_op_state = EDAC_OPSTATE_INT;
1382 		break;
1383 	}
1384 
1385 	ppc4xx_edac_printk(KERN_INFO, "Reporting type: %s\n",
1386 			   ((edac_op_state == EDAC_OPSTATE_POLL) ?
1387 			    EDAC_OPSTATE_POLL_STR :
1388 			    ((edac_op_state == EDAC_OPSTATE_INT) ?
1389 			     EDAC_OPSTATE_INT_STR :
1390 			     EDAC_OPSTATE_UNKNOWN_STR)));
1391 }
1392 
1393 /**
1394  * ppc4xx_edac_init - driver/module insertion entry point
1395  *
1396  * This routine is the driver/module insertion entry point. It
1397  * initializes the EDAC memory controller reporting state and
1398  * registers the driver as an OpenFirmware device tree platform
1399  * driver.
1400  */
1401 static int __init
ppc4xx_edac_init(void)1402 ppc4xx_edac_init(void)
1403 {
1404 	ppc4xx_edac_printk(KERN_INFO, PPC4XX_EDAC_MODULE_REVISION "\n");
1405 
1406 	ppc4xx_edac_opstate_init();
1407 
1408 	return platform_driver_register(&ppc4xx_edac_driver);
1409 }
1410 
1411 /**
1412  * ppc4xx_edac_exit - driver/module removal entry point
1413  *
1414  * This routine is the driver/module removal entry point. It
1415  * unregisters the driver as an OpenFirmware device tree platform
1416  * driver.
1417  */
1418 static void __exit
ppc4xx_edac_exit(void)1419 ppc4xx_edac_exit(void)
1420 {
1421 	platform_driver_unregister(&ppc4xx_edac_driver);
1422 }
1423 
1424 module_init(ppc4xx_edac_init);
1425 module_exit(ppc4xx_edac_exit);
1426 
1427 MODULE_LICENSE("GPL v2");
1428 MODULE_AUTHOR("Grant Erickson <gerickson@nuovations.com>");
1429 MODULE_DESCRIPTION("EDAC MC Driver for the PPC4xx IBM DDR2 Memory Controller");
1430 module_param(edac_op_state, int, 0444);
1431 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting State: "
1432 		 "0=" EDAC_OPSTATE_POLL_STR ", 2=" EDAC_OPSTATE_INT_STR);
1433