xref: /linux/drivers/edac/x38_edac.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Intel X38 Memory Controller kernel module
3  * Copyright (C) 2008 Cluster Computing, Inc.
4  *
5  * This file may be distributed under the terms of the
6  * GNU General Public License.
7  *
8  * This file is based on i3200_edac.c
9  *
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 
18 #include <asm-generic/io-64-nonatomic-lo-hi.h>
19 #include "edac_core.h"
20 
21 #define X38_REVISION		"1.1"
22 
23 #define EDAC_MOD_STR		"x38_edac"
24 
25 #define PCI_DEVICE_ID_INTEL_X38_HB	0x29e0
26 
27 #define X38_RANKS		8
28 #define X38_RANKS_PER_CHANNEL	4
29 #define X38_CHANNELS		2
30 
31 /* Intel X38 register addresses - device 0 function 0 - DRAM Controller */
32 
33 #define X38_MCHBAR_LOW	0x48	/* MCH Memory Mapped Register BAR */
34 #define X38_MCHBAR_HIGH	0x4c
35 #define X38_MCHBAR_MASK	0xfffffc000ULL	/* bits 35:14 */
36 #define X38_MMR_WINDOW_SIZE	16384
37 
38 #define X38_TOM	0xa0	/* Top of Memory (16b)
39 				 *
40 				 * 15:10 reserved
41 				 *  9:0  total populated physical memory
42 				 */
43 #define X38_TOM_MASK	0x3ff	/* bits 9:0 */
44 #define X38_TOM_SHIFT 26	/* 64MiB grain */
45 
46 #define X38_ERRSTS	0xc8	/* Error Status Register (16b)
47 				 *
48 				 * 15    reserved
49 				 * 14    Isochronous TBWRR Run Behind FIFO Full
50 				 *       (ITCV)
51 				 * 13    Isochronous TBWRR Run Behind FIFO Put
52 				 *       (ITSTV)
53 				 * 12    reserved
54 				 * 11    MCH Thermal Sensor Event
55 				 *       for SMI/SCI/SERR (GTSE)
56 				 * 10    reserved
57 				 *  9    LOCK to non-DRAM Memory Flag (LCKF)
58 				 *  8    reserved
59 				 *  7    DRAM Throttle Flag (DTF)
60 				 *  6:2  reserved
61 				 *  1    Multi-bit DRAM ECC Error Flag (DMERR)
62 				 *  0    Single-bit DRAM ECC Error Flag (DSERR)
63 				 */
64 #define X38_ERRSTS_UE		0x0002
65 #define X38_ERRSTS_CE		0x0001
66 #define X38_ERRSTS_BITS	(X38_ERRSTS_UE | X38_ERRSTS_CE)
67 
68 
69 /* Intel  MMIO register space - device 0 function 0 - MMR space */
70 
71 #define X38_C0DRB	0x200	/* Channel 0 DRAM Rank Boundary (16b x 4)
72 				 *
73 				 * 15:10 reserved
74 				 *  9:0  Channel 0 DRAM Rank Boundary Address
75 				 */
76 #define X38_C1DRB	0x600	/* Channel 1 DRAM Rank Boundary (16b x 4) */
77 #define X38_DRB_MASK	0x3ff	/* bits 9:0 */
78 #define X38_DRB_SHIFT 26	/* 64MiB grain */
79 
80 #define X38_C0ECCERRLOG 0x280	/* Channel 0 ECC Error Log (64b)
81 				 *
82 				 * 63:48 Error Column Address (ERRCOL)
83 				 * 47:32 Error Row Address (ERRROW)
84 				 * 31:29 Error Bank Address (ERRBANK)
85 				 * 28:27 Error Rank Address (ERRRANK)
86 				 * 26:24 reserved
87 				 * 23:16 Error Syndrome (ERRSYND)
88 				 * 15: 2 reserved
89 				 *    1  Multiple Bit Error Status (MERRSTS)
90 				 *    0  Correctable Error Status (CERRSTS)
91 				 */
92 #define X38_C1ECCERRLOG 0x680	/* Channel 1 ECC Error Log (64b) */
93 #define X38_ECCERRLOG_CE	0x1
94 #define X38_ECCERRLOG_UE	0x2
95 #define X38_ECCERRLOG_RANK_BITS	0x18000000
96 #define X38_ECCERRLOG_SYNDROME_BITS	0xff0000
97 
98 #define X38_CAPID0 0xe0	/* see P.94 of spec for details */
99 
100 static int x38_channel_num;
101 
102 static int how_many_channel(struct pci_dev *pdev)
103 {
104 	unsigned char capid0_8b; /* 8th byte of CAPID0 */
105 
106 	pci_read_config_byte(pdev, X38_CAPID0 + 8, &capid0_8b);
107 	if (capid0_8b & 0x20) {	/* check DCD: Dual Channel Disable */
108 		edac_dbg(0, "In single channel mode\n");
109 		x38_channel_num = 1;
110 	} else {
111 		edac_dbg(0, "In dual channel mode\n");
112 		x38_channel_num = 2;
113 	}
114 
115 	return x38_channel_num;
116 }
117 
118 static unsigned long eccerrlog_syndrome(u64 log)
119 {
120 	return (log & X38_ECCERRLOG_SYNDROME_BITS) >> 16;
121 }
122 
123 static int eccerrlog_row(int channel, u64 log)
124 {
125 	return ((log & X38_ECCERRLOG_RANK_BITS) >> 27) |
126 		(channel * X38_RANKS_PER_CHANNEL);
127 }
128 
129 enum x38_chips {
130 	X38 = 0,
131 };
132 
133 struct x38_dev_info {
134 	const char *ctl_name;
135 };
136 
137 struct x38_error_info {
138 	u16 errsts;
139 	u16 errsts2;
140 	u64 eccerrlog[X38_CHANNELS];
141 };
142 
143 static const struct x38_dev_info x38_devs[] = {
144 	[X38] = {
145 		.ctl_name = "x38"},
146 };
147 
148 static struct pci_dev *mci_pdev;
149 static int x38_registered = 1;
150 
151 
152 static void x38_clear_error_info(struct mem_ctl_info *mci)
153 {
154 	struct pci_dev *pdev;
155 
156 	pdev = to_pci_dev(mci->pdev);
157 
158 	/*
159 	 * Clear any error bits.
160 	 * (Yes, we really clear bits by writing 1 to them.)
161 	 */
162 	pci_write_bits16(pdev, X38_ERRSTS, X38_ERRSTS_BITS,
163 			 X38_ERRSTS_BITS);
164 }
165 
166 static void x38_get_and_clear_error_info(struct mem_ctl_info *mci,
167 				 struct x38_error_info *info)
168 {
169 	struct pci_dev *pdev;
170 	void __iomem *window = mci->pvt_info;
171 
172 	pdev = to_pci_dev(mci->pdev);
173 
174 	/*
175 	 * This is a mess because there is no atomic way to read all the
176 	 * registers at once and the registers can transition from CE being
177 	 * overwritten by UE.
178 	 */
179 	pci_read_config_word(pdev, X38_ERRSTS, &info->errsts);
180 	if (!(info->errsts & X38_ERRSTS_BITS))
181 		return;
182 
183 	info->eccerrlog[0] = lo_hi_readq(window + X38_C0ECCERRLOG);
184 	if (x38_channel_num == 2)
185 		info->eccerrlog[1] = lo_hi_readq(window + X38_C1ECCERRLOG);
186 
187 	pci_read_config_word(pdev, X38_ERRSTS, &info->errsts2);
188 
189 	/*
190 	 * If the error is the same for both reads then the first set
191 	 * of reads is valid.  If there is a change then there is a CE
192 	 * with no info and the second set of reads is valid and
193 	 * should be UE info.
194 	 */
195 	if ((info->errsts ^ info->errsts2) & X38_ERRSTS_BITS) {
196 		info->eccerrlog[0] = lo_hi_readq(window + X38_C0ECCERRLOG);
197 		if (x38_channel_num == 2)
198 			info->eccerrlog[1] =
199 				lo_hi_readq(window + X38_C1ECCERRLOG);
200 	}
201 
202 	x38_clear_error_info(mci);
203 }
204 
205 static void x38_process_error_info(struct mem_ctl_info *mci,
206 				struct x38_error_info *info)
207 {
208 	int channel;
209 	u64 log;
210 
211 	if (!(info->errsts & X38_ERRSTS_BITS))
212 		return;
213 
214 	if ((info->errsts ^ info->errsts2) & X38_ERRSTS_BITS) {
215 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, 0, 0, 0,
216 				     -1, -1, -1,
217 				     "UE overwrote CE", "");
218 		info->errsts = info->errsts2;
219 	}
220 
221 	for (channel = 0; channel < x38_channel_num; channel++) {
222 		log = info->eccerrlog[channel];
223 		if (log & X38_ECCERRLOG_UE) {
224 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
225 					     0, 0, 0,
226 					     eccerrlog_row(channel, log),
227 					     -1, -1,
228 					     "x38 UE", "");
229 		} else if (log & X38_ECCERRLOG_CE) {
230 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
231 					     0, 0, eccerrlog_syndrome(log),
232 					     eccerrlog_row(channel, log),
233 					     -1, -1,
234 					     "x38 CE", "");
235 		}
236 	}
237 }
238 
239 static void x38_check(struct mem_ctl_info *mci)
240 {
241 	struct x38_error_info info;
242 
243 	edac_dbg(1, "MC%d\n", mci->mc_idx);
244 	x38_get_and_clear_error_info(mci, &info);
245 	x38_process_error_info(mci, &info);
246 }
247 
248 static void __iomem *x38_map_mchbar(struct pci_dev *pdev)
249 {
250 	union {
251 		u64 mchbar;
252 		struct {
253 			u32 mchbar_low;
254 			u32 mchbar_high;
255 		};
256 	} u;
257 	void __iomem *window;
258 
259 	pci_read_config_dword(pdev, X38_MCHBAR_LOW, &u.mchbar_low);
260 	pci_write_config_dword(pdev, X38_MCHBAR_LOW, u.mchbar_low | 0x1);
261 	pci_read_config_dword(pdev, X38_MCHBAR_HIGH, &u.mchbar_high);
262 	u.mchbar &= X38_MCHBAR_MASK;
263 
264 	if (u.mchbar != (resource_size_t)u.mchbar) {
265 		printk(KERN_ERR
266 			"x38: mmio space beyond accessible range (0x%llx)\n",
267 			(unsigned long long)u.mchbar);
268 		return NULL;
269 	}
270 
271 	window = ioremap_nocache(u.mchbar, X38_MMR_WINDOW_SIZE);
272 	if (!window)
273 		printk(KERN_ERR "x38: cannot map mmio space at 0x%llx\n",
274 			(unsigned long long)u.mchbar);
275 
276 	return window;
277 }
278 
279 
280 static void x38_get_drbs(void __iomem *window,
281 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
282 {
283 	int i;
284 
285 	for (i = 0; i < X38_RANKS_PER_CHANNEL; i++) {
286 		drbs[0][i] = readw(window + X38_C0DRB + 2*i) & X38_DRB_MASK;
287 		drbs[1][i] = readw(window + X38_C1DRB + 2*i) & X38_DRB_MASK;
288 	}
289 }
290 
291 static bool x38_is_stacked(struct pci_dev *pdev,
292 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
293 {
294 	u16 tom;
295 
296 	pci_read_config_word(pdev, X38_TOM, &tom);
297 	tom &= X38_TOM_MASK;
298 
299 	return drbs[X38_CHANNELS - 1][X38_RANKS_PER_CHANNEL - 1] == tom;
300 }
301 
302 static unsigned long drb_to_nr_pages(
303 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL],
304 			bool stacked, int channel, int rank)
305 {
306 	int n;
307 
308 	n = drbs[channel][rank];
309 	if (rank > 0)
310 		n -= drbs[channel][rank - 1];
311 	if (stacked && (channel == 1) && drbs[channel][rank] ==
312 				drbs[channel][X38_RANKS_PER_CHANNEL - 1]) {
313 		n -= drbs[0][X38_RANKS_PER_CHANNEL - 1];
314 	}
315 
316 	n <<= (X38_DRB_SHIFT - PAGE_SHIFT);
317 	return n;
318 }
319 
320 static int x38_probe1(struct pci_dev *pdev, int dev_idx)
321 {
322 	int rc;
323 	int i, j;
324 	struct mem_ctl_info *mci = NULL;
325 	struct edac_mc_layer layers[2];
326 	u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL];
327 	bool stacked;
328 	void __iomem *window;
329 
330 	edac_dbg(0, "MC:\n");
331 
332 	window = x38_map_mchbar(pdev);
333 	if (!window)
334 		return -ENODEV;
335 
336 	x38_get_drbs(window, drbs);
337 
338 	how_many_channel(pdev);
339 
340 	/* FIXME: unconventional pvt_info usage */
341 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
342 	layers[0].size = X38_RANKS;
343 	layers[0].is_virt_csrow = true;
344 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
345 	layers[1].size = x38_channel_num;
346 	layers[1].is_virt_csrow = false;
347 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
348 	if (!mci)
349 		return -ENOMEM;
350 
351 	edac_dbg(3, "MC: init mci\n");
352 
353 	mci->pdev = &pdev->dev;
354 	mci->mtype_cap = MEM_FLAG_DDR2;
355 
356 	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
357 	mci->edac_cap = EDAC_FLAG_SECDED;
358 
359 	mci->mod_name = EDAC_MOD_STR;
360 	mci->mod_ver = X38_REVISION;
361 	mci->ctl_name = x38_devs[dev_idx].ctl_name;
362 	mci->dev_name = pci_name(pdev);
363 	mci->edac_check = x38_check;
364 	mci->ctl_page_to_phys = NULL;
365 	mci->pvt_info = window;
366 
367 	stacked = x38_is_stacked(pdev, drbs);
368 
369 	/*
370 	 * The dram rank boundary (DRB) reg values are boundary addresses
371 	 * for each DRAM rank with a granularity of 64MB.  DRB regs are
372 	 * cumulative; the last one will contain the total memory
373 	 * contained in all ranks.
374 	 */
375 	for (i = 0; i < mci->nr_csrows; i++) {
376 		unsigned long nr_pages;
377 		struct csrow_info *csrow = mci->csrows[i];
378 
379 		nr_pages = drb_to_nr_pages(drbs, stacked,
380 			i / X38_RANKS_PER_CHANNEL,
381 			i % X38_RANKS_PER_CHANNEL);
382 
383 		if (nr_pages == 0)
384 			continue;
385 
386 		for (j = 0; j < x38_channel_num; j++) {
387 			struct dimm_info *dimm = csrow->channels[j]->dimm;
388 
389 			dimm->nr_pages = nr_pages / x38_channel_num;
390 			dimm->grain = nr_pages << PAGE_SHIFT;
391 			dimm->mtype = MEM_DDR2;
392 			dimm->dtype = DEV_UNKNOWN;
393 			dimm->edac_mode = EDAC_UNKNOWN;
394 		}
395 	}
396 
397 	x38_clear_error_info(mci);
398 
399 	rc = -ENODEV;
400 	if (edac_mc_add_mc(mci)) {
401 		edac_dbg(3, "MC: failed edac_mc_add_mc()\n");
402 		goto fail;
403 	}
404 
405 	/* get this far and it's successful */
406 	edac_dbg(3, "MC: success\n");
407 	return 0;
408 
409 fail:
410 	iounmap(window);
411 	if (mci)
412 		edac_mc_free(mci);
413 
414 	return rc;
415 }
416 
417 static int x38_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
418 {
419 	int rc;
420 
421 	edac_dbg(0, "MC:\n");
422 
423 	if (pci_enable_device(pdev) < 0)
424 		return -EIO;
425 
426 	rc = x38_probe1(pdev, ent->driver_data);
427 	if (!mci_pdev)
428 		mci_pdev = pci_dev_get(pdev);
429 
430 	return rc;
431 }
432 
433 static void x38_remove_one(struct pci_dev *pdev)
434 {
435 	struct mem_ctl_info *mci;
436 
437 	edac_dbg(0, "\n");
438 
439 	mci = edac_mc_del_mc(&pdev->dev);
440 	if (!mci)
441 		return;
442 
443 	iounmap(mci->pvt_info);
444 
445 	edac_mc_free(mci);
446 }
447 
448 static const struct pci_device_id x38_pci_tbl[] = {
449 	{
450 	 PCI_VEND_DEV(INTEL, X38_HB), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
451 	 X38},
452 	{
453 	 0,
454 	 }			/* 0 terminated list. */
455 };
456 
457 MODULE_DEVICE_TABLE(pci, x38_pci_tbl);
458 
459 static struct pci_driver x38_driver = {
460 	.name = EDAC_MOD_STR,
461 	.probe = x38_init_one,
462 	.remove = x38_remove_one,
463 	.id_table = x38_pci_tbl,
464 };
465 
466 static int __init x38_init(void)
467 {
468 	int pci_rc;
469 
470 	edac_dbg(3, "MC:\n");
471 
472 	/* Ensure that the OPSTATE is set correctly for POLL or NMI */
473 	opstate_init();
474 
475 	pci_rc = pci_register_driver(&x38_driver);
476 	if (pci_rc < 0)
477 		goto fail0;
478 
479 	if (!mci_pdev) {
480 		x38_registered = 0;
481 		mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
482 					PCI_DEVICE_ID_INTEL_X38_HB, NULL);
483 		if (!mci_pdev) {
484 			edac_dbg(0, "x38 pci_get_device fail\n");
485 			pci_rc = -ENODEV;
486 			goto fail1;
487 		}
488 
489 		pci_rc = x38_init_one(mci_pdev, x38_pci_tbl);
490 		if (pci_rc < 0) {
491 			edac_dbg(0, "x38 init fail\n");
492 			pci_rc = -ENODEV;
493 			goto fail1;
494 		}
495 	}
496 
497 	return 0;
498 
499 fail1:
500 	pci_unregister_driver(&x38_driver);
501 
502 fail0:
503 	pci_dev_put(mci_pdev);
504 
505 	return pci_rc;
506 }
507 
508 static void __exit x38_exit(void)
509 {
510 	edac_dbg(3, "MC:\n");
511 
512 	pci_unregister_driver(&x38_driver);
513 	if (!x38_registered) {
514 		x38_remove_one(mci_pdev);
515 		pci_dev_put(mci_pdev);
516 	}
517 }
518 
519 module_init(x38_init);
520 module_exit(x38_exit);
521 
522 MODULE_LICENSE("GPL");
523 MODULE_AUTHOR("Cluster Computing, Inc. Hitoshi Mitake");
524 MODULE_DESCRIPTION("MC support for Intel X38 memory hub controllers");
525 
526 module_param(edac_op_state, int, 0444);
527 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
528