xref: /linux/drivers/edac/i82975x_edac.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Intel 82975X Memory Controller kernel module
3  * (C) 2007 aCarLab (India) Pvt. Ltd. (http://acarlab.com)
4  * (C) 2007 jetzbroadband (http://jetzbroadband.com)
5  * This file may be distributed under the terms of the
6  * GNU General Public License.
7  *
8  * Written by Arvind R.
9  *   Copied from i82875p_edac.c source:
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/pci.h>
15 #include <linux/pci_ids.h>
16 #include <linux/edac.h>
17 #include "edac_core.h"
18 
19 #define I82975X_REVISION	" Ver: 1.0.0"
20 #define EDAC_MOD_STR		"i82975x_edac"
21 
22 #define i82975x_printk(level, fmt, arg...) \
23 	edac_printk(level, "i82975x", fmt, ##arg)
24 
25 #define i82975x_mc_printk(mci, level, fmt, arg...) \
26 	edac_mc_chipset_printk(mci, level, "i82975x", fmt, ##arg)
27 
28 #ifndef PCI_DEVICE_ID_INTEL_82975_0
29 #define PCI_DEVICE_ID_INTEL_82975_0	0x277c
30 #endif				/* PCI_DEVICE_ID_INTEL_82975_0 */
31 
32 #define I82975X_NR_DIMMS		8
33 #define I82975X_NR_CSROWS(nr_chans)	(I82975X_NR_DIMMS / (nr_chans))
34 
35 /* Intel 82975X register addresses - device 0 function 0 - DRAM Controller */
36 #define I82975X_EAP		0x58	/* Dram Error Address Pointer (32b)
37 					 *
38 					 * 31:7  128 byte cache-line address
39 					 * 6:1   reserved
40 					 * 0     0: CH0; 1: CH1
41 					 */
42 
43 #define I82975X_DERRSYN		0x5c	/* Dram Error SYNdrome (8b)
44 					 *
45 					 *  7:0  DRAM ECC Syndrome
46 					 */
47 
48 #define I82975X_DES		0x5d	/* Dram ERRor DeSTination (8b)
49 					 * 0h:    Processor Memory Reads
50 					 * 1h:7h  reserved
51 					 * More - See Page 65 of Intel DocSheet.
52 					 */
53 
54 #define I82975X_ERRSTS		0xc8	/* Error Status Register (16b)
55 					 *
56 					 * 15:12 reserved
57 					 * 11    Thermal Sensor Event
58 					 * 10    reserved
59 					 *  9    non-DRAM lock error (ndlock)
60 					 *  8    Refresh Timeout
61 					 *  7:2  reserved
62 					 *  1    ECC UE (multibit DRAM error)
63 					 *  0    ECC CE (singlebit DRAM error)
64 					 */
65 
66 /* Error Reporting is supported by 3 mechanisms:
67   1. DMI SERR generation  ( ERRCMD )
68   2. SMI DMI  generation  ( SMICMD )
69   3. SCI DMI  generation  ( SCICMD )
70 NOTE: Only ONE of the three must be enabled
71 */
72 #define I82975X_ERRCMD		0xca	/* Error Command (16b)
73 					 *
74 					 * 15:12 reserved
75 					 * 11    Thermal Sensor Event
76 					 * 10    reserved
77 					 *  9    non-DRAM lock error (ndlock)
78 					 *  8    Refresh Timeout
79 					 *  7:2  reserved
80 					 *  1    ECC UE (multibit DRAM error)
81 					 *  0    ECC CE (singlebit DRAM error)
82 					 */
83 
84 #define I82975X_SMICMD		0xcc	/* Error Command (16b)
85 					 *
86 					 * 15:2  reserved
87 					 *  1    ECC UE (multibit DRAM error)
88 					 *  0    ECC CE (singlebit DRAM error)
89 					 */
90 
91 #define I82975X_SCICMD		0xce	/* Error Command (16b)
92 					 *
93 					 * 15:2  reserved
94 					 *  1    ECC UE (multibit DRAM error)
95 					 *  0    ECC CE (singlebit DRAM error)
96 					 */
97 
98 #define I82975X_XEAP	0xfc	/* Extended Dram Error Address Pointer (8b)
99 					 *
100 					 * 7:1   reserved
101 					 * 0     Bit32 of the Dram Error Address
102 					 */
103 
104 #define I82975X_MCHBAR		0x44	/*
105 					 *
106 					 * 31:14 Base Addr of 16K memory-mapped
107 					 *	configuration space
108 					 * 13:1  reserverd
109 					 *  0    mem-mapped config space enable
110 					 */
111 
112 /* NOTE: Following addresses have to indexed using MCHBAR offset (44h, 32b) */
113 /* Intel 82975x memory mapped register space */
114 
115 #define I82975X_DRB_SHIFT 25	/* fixed 32MiB grain */
116 
117 #define I82975X_DRB		0x100	/* DRAM Row Boundary (8b x 8)
118 					 *
119 					 * 7   set to 1 in highest DRB of
120 					 *	channel if 4GB in ch.
121 					 * 6:2 upper boundary of rank in
122 					 *	32MB grains
123 					 * 1:0 set to 0
124 					 */
125 #define I82975X_DRB_CH0R0		0x100
126 #define I82975X_DRB_CH0R1		0x101
127 #define I82975X_DRB_CH0R2		0x102
128 #define I82975X_DRB_CH0R3		0x103
129 #define I82975X_DRB_CH1R0		0x180
130 #define I82975X_DRB_CH1R1		0x181
131 #define I82975X_DRB_CH1R2		0x182
132 #define I82975X_DRB_CH1R3		0x183
133 
134 
135 #define I82975X_DRA		0x108	/* DRAM Row Attribute (4b x 8)
136 					 *  defines the PAGE SIZE to be used
137 					 *	for the rank
138 					 *  7    reserved
139 					 *  6:4  row attr of odd rank, i.e. 1
140 					 *  3    reserved
141 					 *  2:0  row attr of even rank, i.e. 0
142 					 *
143 					 * 000 = unpopulated
144 					 * 001 = reserved
145 					 * 010 = 4KiB
146 					 * 011 = 8KiB
147 					 * 100 = 16KiB
148 					 * others = reserved
149 					 */
150 #define I82975X_DRA_CH0R01		0x108
151 #define I82975X_DRA_CH0R23		0x109
152 #define I82975X_DRA_CH1R01		0x188
153 #define I82975X_DRA_CH1R23		0x189
154 
155 
156 #define I82975X_BNKARC	0x10e /* Type of device in each rank - Bank Arch (16b)
157 					 *
158 					 * 15:8  reserved
159 					 * 7:6  Rank 3 architecture
160 					 * 5:4  Rank 2 architecture
161 					 * 3:2  Rank 1 architecture
162 					 * 1:0  Rank 0 architecture
163 					 *
164 					 * 00 => 4 banks
165 					 * 01 => 8 banks
166 					 */
167 #define I82975X_C0BNKARC	0x10e
168 #define I82975X_C1BNKARC	0x18e
169 
170 
171 
172 #define I82975X_DRC		0x120 /* DRAM Controller Mode0 (32b)
173 					 *
174 					 * 31:30 reserved
175 					 * 29    init complete
176 					 * 28:11 reserved, according to Intel
177 					 *    22:21 number of channels
178 					 *		00=1 01=2 in 82875
179 					 *		seems to be ECC mode
180 					 *		bits in 82975 in Asus
181 					 *		P5W
182 					 *	 19:18 Data Integ Mode
183 					 *		00=none 01=ECC in 82875
184 					 * 10:8  refresh mode
185 					 *  7    reserved
186 					 *  6:4  mode select
187 					 *  3:2  reserved
188 					 *  1:0  DRAM type 10=Second Revision
189 					 *		DDR2 SDRAM
190 					 *         00, 01, 11 reserved
191 					 */
192 #define I82975X_DRC_CH0M0		0x120
193 #define I82975X_DRC_CH1M0		0x1A0
194 
195 
196 #define I82975X_DRC_M1	0x124 /* DRAM Controller Mode1 (32b)
197 					 * 31	0=Standard Address Map
198 					 *	1=Enhanced Address Map
199 					 * 30:0	reserved
200 					 */
201 
202 #define I82975X_DRC_CH0M1		0x124
203 #define I82975X_DRC_CH1M1		0x1A4
204 
205 enum i82975x_chips {
206 	I82975X = 0,
207 };
208 
209 struct i82975x_pvt {
210 	void __iomem *mch_window;
211 };
212 
213 struct i82975x_dev_info {
214 	const char *ctl_name;
215 };
216 
217 struct i82975x_error_info {
218 	u16 errsts;
219 	u32 eap;
220 	u8 des;
221 	u8 derrsyn;
222 	u16 errsts2;
223 	u8 chan;		/* the channel is bit 0 of EAP */
224 	u8 xeap;		/* extended eap bit */
225 };
226 
227 static const struct i82975x_dev_info i82975x_devs[] = {
228 	[I82975X] = {
229 		.ctl_name = "i82975x"
230 	},
231 };
232 
233 static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
234 					 * already registered driver
235 					 */
236 
237 static int i82975x_registered = 1;
238 
239 static void i82975x_get_error_info(struct mem_ctl_info *mci,
240 		struct i82975x_error_info *info)
241 {
242 	struct pci_dev *pdev;
243 
244 	pdev = to_pci_dev(mci->pdev);
245 
246 	/*
247 	 * This is a mess because there is no atomic way to read all the
248 	 * registers at once and the registers can transition from CE being
249 	 * overwritten by UE.
250 	 */
251 	pci_read_config_word(pdev, I82975X_ERRSTS, &info->errsts);
252 	pci_read_config_dword(pdev, I82975X_EAP, &info->eap);
253 	pci_read_config_byte(pdev, I82975X_XEAP, &info->xeap);
254 	pci_read_config_byte(pdev, I82975X_DES, &info->des);
255 	pci_read_config_byte(pdev, I82975X_DERRSYN, &info->derrsyn);
256 	pci_read_config_word(pdev, I82975X_ERRSTS, &info->errsts2);
257 
258 	pci_write_bits16(pdev, I82975X_ERRSTS, 0x0003, 0x0003);
259 
260 	/*
261 	 * If the error is the same then we can for both reads then
262 	 * the first set of reads is valid.  If there is a change then
263 	 * there is a CE no info and the second set of reads is valid
264 	 * and should be UE info.
265 	 */
266 	if (!(info->errsts2 & 0x0003))
267 		return;
268 
269 	if ((info->errsts ^ info->errsts2) & 0x0003) {
270 		pci_read_config_dword(pdev, I82975X_EAP, &info->eap);
271 		pci_read_config_byte(pdev, I82975X_XEAP, &info->xeap);
272 		pci_read_config_byte(pdev, I82975X_DES, &info->des);
273 		pci_read_config_byte(pdev, I82975X_DERRSYN,
274 				&info->derrsyn);
275 	}
276 }
277 
278 static int i82975x_process_error_info(struct mem_ctl_info *mci,
279 		struct i82975x_error_info *info, int handle_errors)
280 {
281 	int row, chan;
282 	unsigned long offst, page;
283 
284 	if (!(info->errsts2 & 0x0003))
285 		return 0;
286 
287 	if (!handle_errors)
288 		return 1;
289 
290 	if ((info->errsts ^ info->errsts2) & 0x0003) {
291 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, 0, 0, 0,
292 				     -1, -1, -1, "UE overwrote CE", "");
293 		info->errsts = info->errsts2;
294 	}
295 
296 	page = (unsigned long) info->eap;
297 	page >>= 1;
298 	if (info->xeap & 1)
299 		page |= 0x80000000;
300 	page >>= (PAGE_SHIFT - 1);
301 	row = edac_mc_find_csrow_by_page(mci, page);
302 
303 	if (row == -1)	{
304 		i82975x_mc_printk(mci, KERN_ERR, "error processing EAP:\n"
305 			"\tXEAP=%u\n"
306 			"\t EAP=0x%08x\n"
307 			"\tPAGE=0x%08x\n",
308 			(info->xeap & 1) ? 1 : 0, info->eap, (unsigned int) page);
309 		return 0;
310 	}
311 	chan = (mci->csrows[row]->nr_channels == 1) ? 0 : info->eap & 1;
312 	offst = info->eap
313 			& ((1 << PAGE_SHIFT) -
314 			   (1 << mci->csrows[row]->channels[chan]->dimm->grain));
315 
316 	if (info->errsts & 0x0002)
317 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
318 				     page, offst, 0,
319 				     row, -1, -1,
320 				     "i82975x UE", "");
321 	else
322 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
323 				     page, offst, info->derrsyn,
324 				     row, chan ? chan : 0, -1,
325 				     "i82975x CE", "");
326 
327 	return 1;
328 }
329 
330 static void i82975x_check(struct mem_ctl_info *mci)
331 {
332 	struct i82975x_error_info info;
333 
334 	edac_dbg(1, "MC%d\n", mci->mc_idx);
335 	i82975x_get_error_info(mci, &info);
336 	i82975x_process_error_info(mci, &info, 1);
337 }
338 
339 /* Return 1 if dual channel mode is active.  Else return 0. */
340 static int dual_channel_active(void __iomem *mch_window)
341 {
342 	/*
343 	 * We treat interleaved-symmetric configuration as dual-channel - EAP's
344 	 * bit-0 giving the channel of the error location.
345 	 *
346 	 * All other configurations are treated as single channel - the EAP's
347 	 * bit-0 will resolve ok in symmetric area of mixed
348 	 * (symmetric/asymmetric) configurations
349 	 */
350 	u8	drb[4][2];
351 	int	row;
352 	int    dualch;
353 
354 	for (dualch = 1, row = 0; dualch && (row < 4); row++) {
355 		drb[row][0] = readb(mch_window + I82975X_DRB + row);
356 		drb[row][1] = readb(mch_window + I82975X_DRB + row + 0x80);
357 		dualch = dualch && (drb[row][0] == drb[row][1]);
358 	}
359 	return dualch;
360 }
361 
362 static enum dev_type i82975x_dram_type(void __iomem *mch_window, int rank)
363 {
364 	/*
365 	 * ECC is possible on i92975x ONLY with DEV_X8
366 	 */
367 	return DEV_X8;
368 }
369 
370 static void i82975x_init_csrows(struct mem_ctl_info *mci,
371 		struct pci_dev *pdev, void __iomem *mch_window)
372 {
373 	struct csrow_info *csrow;
374 	unsigned long last_cumul_size;
375 	u8 value;
376 	u32 cumul_size, nr_pages;
377 	int index, chan;
378 	struct dimm_info *dimm;
379 	enum dev_type dtype;
380 
381 	last_cumul_size = 0;
382 
383 	/*
384 	 * 82875 comment:
385 	 * The dram row boundary (DRB) reg values are boundary address
386 	 * for each DRAM row with a granularity of 32 or 64MB (single/dual
387 	 * channel operation).  DRB regs are cumulative; therefore DRB7 will
388 	 * contain the total memory contained in all rows.
389 	 *
390 	 */
391 
392 	for (index = 0; index < mci->nr_csrows; index++) {
393 		csrow = mci->csrows[index];
394 
395 		value = readb(mch_window + I82975X_DRB + index +
396 					((index >= 4) ? 0x80 : 0));
397 		cumul_size = value;
398 		cumul_size <<= (I82975X_DRB_SHIFT - PAGE_SHIFT);
399 		/*
400 		 * Adjust cumul_size w.r.t number of channels
401 		 *
402 		 */
403 		if (csrow->nr_channels > 1)
404 			cumul_size <<= 1;
405 		edac_dbg(3, "(%d) cumul_size 0x%x\n", index, cumul_size);
406 
407 		nr_pages = cumul_size - last_cumul_size;
408 		if (!nr_pages)
409 			continue;
410 
411 		/*
412 		 * Initialise dram labels
413 		 * index values:
414 		 *   [0-7] for single-channel; i.e. csrow->nr_channels = 1
415 		 *   [0-3] for dual-channel; i.e. csrow->nr_channels = 2
416 		 */
417 		dtype = i82975x_dram_type(mch_window, index);
418 		for (chan = 0; chan < csrow->nr_channels; chan++) {
419 			dimm = mci->csrows[index]->channels[chan]->dimm;
420 
421 			dimm->nr_pages = nr_pages / csrow->nr_channels;
422 
423 			snprintf(csrow->channels[chan]->dimm->label, EDAC_MC_LABEL_LEN, "DIMM %c%d",
424 				 (chan == 0) ? 'A' : 'B',
425 				 index);
426 			dimm->grain = 1 << 7;	/* 128Byte cache-line resolution */
427 			dimm->dtype = i82975x_dram_type(mch_window, index);
428 			dimm->mtype = MEM_DDR2; /* I82975x supports only DDR2 */
429 			dimm->edac_mode = EDAC_SECDED; /* only supported */
430 		}
431 
432 		csrow->first_page = last_cumul_size;
433 		csrow->last_page = cumul_size - 1;
434 		last_cumul_size = cumul_size;
435 	}
436 }
437 
438 /* #define  i82975x_DEBUG_IOMEM */
439 
440 #ifdef i82975x_DEBUG_IOMEM
441 static void i82975x_print_dram_timings(void __iomem *mch_window)
442 {
443 	/*
444 	 * The register meanings are from Intel specs;
445 	 * (shows 13-5-5-5 for 800-DDR2)
446 	 * Asus P5W Bios reports 15-5-4-4
447 	 * What's your religion?
448 	 */
449 	static const int caslats[4] = { 5, 4, 3, 6 };
450 	u32	dtreg[2];
451 
452 	dtreg[0] = readl(mch_window + 0x114);
453 	dtreg[1] = readl(mch_window + 0x194);
454 	i82975x_printk(KERN_INFO, "DRAM Timings :     Ch0    Ch1\n"
455 		"                RAS Active Min = %d     %d\n"
456 		"                CAS latency    =  %d      %d\n"
457 		"                RAS to CAS     =  %d      %d\n"
458 		"                RAS precharge  =  %d      %d\n",
459 		(dtreg[0] >> 19 ) & 0x0f,
460 			(dtreg[1] >> 19) & 0x0f,
461 		caslats[(dtreg[0] >> 8) & 0x03],
462 			caslats[(dtreg[1] >> 8) & 0x03],
463 		((dtreg[0] >> 4) & 0x07) + 2,
464 			((dtreg[1] >> 4) & 0x07) + 2,
465 		(dtreg[0] & 0x07) + 2,
466 			(dtreg[1] & 0x07) + 2
467 	);
468 
469 }
470 #endif
471 
472 static int i82975x_probe1(struct pci_dev *pdev, int dev_idx)
473 {
474 	int rc = -ENODEV;
475 	struct mem_ctl_info *mci;
476 	struct edac_mc_layer layers[2];
477 	struct i82975x_pvt *pvt;
478 	void __iomem *mch_window;
479 	u32 mchbar;
480 	u32 drc[2];
481 	struct i82975x_error_info discard;
482 	int	chans;
483 #ifdef i82975x_DEBUG_IOMEM
484 	u8 c0drb[4];
485 	u8 c1drb[4];
486 #endif
487 
488 	edac_dbg(0, "\n");
489 
490 	pci_read_config_dword(pdev, I82975X_MCHBAR, &mchbar);
491 	if (!(mchbar & 1)) {
492 		edac_dbg(3, "failed, MCHBAR disabled!\n");
493 		goto fail0;
494 	}
495 	mchbar &= 0xffffc000;	/* bits 31:14 used for 16K window */
496 	mch_window = ioremap_nocache(mchbar, 0x1000);
497 
498 #ifdef i82975x_DEBUG_IOMEM
499 	i82975x_printk(KERN_INFO, "MCHBAR real = %0x, remapped = %p\n",
500 					mchbar, mch_window);
501 
502 	c0drb[0] = readb(mch_window + I82975X_DRB_CH0R0);
503 	c0drb[1] = readb(mch_window + I82975X_DRB_CH0R1);
504 	c0drb[2] = readb(mch_window + I82975X_DRB_CH0R2);
505 	c0drb[3] = readb(mch_window + I82975X_DRB_CH0R3);
506 	c1drb[0] = readb(mch_window + I82975X_DRB_CH1R0);
507 	c1drb[1] = readb(mch_window + I82975X_DRB_CH1R1);
508 	c1drb[2] = readb(mch_window + I82975X_DRB_CH1R2);
509 	c1drb[3] = readb(mch_window + I82975X_DRB_CH1R3);
510 	i82975x_printk(KERN_INFO, "DRBCH0R0 = 0x%02x\n", c0drb[0]);
511 	i82975x_printk(KERN_INFO, "DRBCH0R1 = 0x%02x\n", c0drb[1]);
512 	i82975x_printk(KERN_INFO, "DRBCH0R2 = 0x%02x\n", c0drb[2]);
513 	i82975x_printk(KERN_INFO, "DRBCH0R3 = 0x%02x\n", c0drb[3]);
514 	i82975x_printk(KERN_INFO, "DRBCH1R0 = 0x%02x\n", c1drb[0]);
515 	i82975x_printk(KERN_INFO, "DRBCH1R1 = 0x%02x\n", c1drb[1]);
516 	i82975x_printk(KERN_INFO, "DRBCH1R2 = 0x%02x\n", c1drb[2]);
517 	i82975x_printk(KERN_INFO, "DRBCH1R3 = 0x%02x\n", c1drb[3]);
518 #endif
519 
520 	drc[0] = readl(mch_window + I82975X_DRC_CH0M0);
521 	drc[1] = readl(mch_window + I82975X_DRC_CH1M0);
522 #ifdef i82975x_DEBUG_IOMEM
523 	i82975x_printk(KERN_INFO, "DRC_CH0 = %0x, %s\n", drc[0],
524 			((drc[0] >> 21) & 3) == 1 ?
525 				"ECC enabled" : "ECC disabled");
526 	i82975x_printk(KERN_INFO, "DRC_CH1 = %0x, %s\n", drc[1],
527 			((drc[1] >> 21) & 3) == 1 ?
528 				"ECC enabled" : "ECC disabled");
529 
530 	i82975x_printk(KERN_INFO, "C0 BNKARC = %0x\n",
531 		readw(mch_window + I82975X_C0BNKARC));
532 	i82975x_printk(KERN_INFO, "C1 BNKARC = %0x\n",
533 		readw(mch_window + I82975X_C1BNKARC));
534 	i82975x_print_dram_timings(mch_window);
535 	goto fail1;
536 #endif
537 	if (!(((drc[0] >> 21) & 3) == 1 || ((drc[1] >> 21) & 3) == 1)) {
538 		i82975x_printk(KERN_INFO, "ECC disabled on both channels.\n");
539 		goto fail1;
540 	}
541 
542 	chans = dual_channel_active(mch_window) + 1;
543 
544 	/* assuming only one controller, index thus is 0 */
545 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
546 	layers[0].size = I82975X_NR_DIMMS;
547 	layers[0].is_virt_csrow = true;
548 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
549 	layers[1].size = I82975X_NR_CSROWS(chans);
550 	layers[1].is_virt_csrow = false;
551 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(*pvt));
552 	if (!mci) {
553 		rc = -ENOMEM;
554 		goto fail1;
555 	}
556 
557 	edac_dbg(3, "init mci\n");
558 	mci->pdev = &pdev->dev;
559 	mci->mtype_cap = MEM_FLAG_DDR2;
560 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
561 	mci->edac_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
562 	mci->mod_name = EDAC_MOD_STR;
563 	mci->mod_ver = I82975X_REVISION;
564 	mci->ctl_name = i82975x_devs[dev_idx].ctl_name;
565 	mci->dev_name = pci_name(pdev);
566 	mci->edac_check = i82975x_check;
567 	mci->ctl_page_to_phys = NULL;
568 	edac_dbg(3, "init pvt\n");
569 	pvt = (struct i82975x_pvt *) mci->pvt_info;
570 	pvt->mch_window = mch_window;
571 	i82975x_init_csrows(mci, pdev, mch_window);
572 	mci->scrub_mode = SCRUB_HW_SRC;
573 	i82975x_get_error_info(mci, &discard);  /* clear counters */
574 
575 	/* finalize this instance of memory controller with edac core */
576 	if (edac_mc_add_mc(mci)) {
577 		edac_dbg(3, "failed edac_mc_add_mc()\n");
578 		goto fail2;
579 	}
580 
581 	/* get this far and it's successful */
582 	edac_dbg(3, "success\n");
583 	return 0;
584 
585 fail2:
586 	edac_mc_free(mci);
587 
588 fail1:
589 	iounmap(mch_window);
590 fail0:
591 	return rc;
592 }
593 
594 /* returns count (>= 0), or negative on error */
595 static int i82975x_init_one(struct pci_dev *pdev,
596 			    const struct pci_device_id *ent)
597 {
598 	int rc;
599 
600 	edac_dbg(0, "\n");
601 
602 	if (pci_enable_device(pdev) < 0)
603 		return -EIO;
604 
605 	rc = i82975x_probe1(pdev, ent->driver_data);
606 
607 	if (mci_pdev == NULL)
608 		mci_pdev = pci_dev_get(pdev);
609 
610 	return rc;
611 }
612 
613 static void i82975x_remove_one(struct pci_dev *pdev)
614 {
615 	struct mem_ctl_info *mci;
616 	struct i82975x_pvt *pvt;
617 
618 	edac_dbg(0, "\n");
619 
620 	mci = edac_mc_del_mc(&pdev->dev);
621 	if (mci  == NULL)
622 		return;
623 
624 	pvt = mci->pvt_info;
625 	if (pvt->mch_window)
626 		iounmap( pvt->mch_window );
627 
628 	edac_mc_free(mci);
629 }
630 
631 static const struct pci_device_id i82975x_pci_tbl[] = {
632 	{
633 		PCI_VEND_DEV(INTEL, 82975_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
634 		I82975X
635 	},
636 	{
637 		0,
638 	}	/* 0 terminated list. */
639 };
640 
641 MODULE_DEVICE_TABLE(pci, i82975x_pci_tbl);
642 
643 static struct pci_driver i82975x_driver = {
644 	.name = EDAC_MOD_STR,
645 	.probe = i82975x_init_one,
646 	.remove = i82975x_remove_one,
647 	.id_table = i82975x_pci_tbl,
648 };
649 
650 static int __init i82975x_init(void)
651 {
652 	int pci_rc;
653 
654 	edac_dbg(3, "\n");
655 
656        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
657        opstate_init();
658 
659 	pci_rc = pci_register_driver(&i82975x_driver);
660 	if (pci_rc < 0)
661 		goto fail0;
662 
663 	if (mci_pdev == NULL) {
664 		mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
665 				PCI_DEVICE_ID_INTEL_82975_0, NULL);
666 
667 		if (!mci_pdev) {
668 			edac_dbg(0, "i82975x pci_get_device fail\n");
669 			pci_rc = -ENODEV;
670 			goto fail1;
671 		}
672 
673 		pci_rc = i82975x_init_one(mci_pdev, i82975x_pci_tbl);
674 
675 		if (pci_rc < 0) {
676 			edac_dbg(0, "i82975x init fail\n");
677 			pci_rc = -ENODEV;
678 			goto fail1;
679 		}
680 	}
681 
682 	return 0;
683 
684 fail1:
685 	pci_unregister_driver(&i82975x_driver);
686 
687 fail0:
688 	pci_dev_put(mci_pdev);
689 	return pci_rc;
690 }
691 
692 static void __exit i82975x_exit(void)
693 {
694 	edac_dbg(3, "\n");
695 
696 	pci_unregister_driver(&i82975x_driver);
697 
698 	if (!i82975x_registered) {
699 		i82975x_remove_one(mci_pdev);
700 		pci_dev_put(mci_pdev);
701 	}
702 }
703 
704 module_init(i82975x_init);
705 module_exit(i82975x_exit);
706 
707 MODULE_LICENSE("GPL");
708 MODULE_AUTHOR("Arvind R. <arvino55@gmail.com>");
709 MODULE_DESCRIPTION("MC support for Intel 82975 memory hub controllers");
710 
711 module_param(edac_op_state, int, 0444);
712 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
713