xref: /openbmc/linux/drivers/edac/x38_edac.c (revision 95e9fd10)
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 #include "edac_core.h"
18 
19 #define X38_REVISION		"1.1"
20 
21 #define EDAC_MOD_STR		"x38_edac"
22 
23 #define PCI_DEVICE_ID_INTEL_X38_HB	0x29e0
24 
25 #define X38_RANKS		8
26 #define X38_RANKS_PER_CHANNEL	4
27 #define X38_CHANNELS		2
28 
29 /* Intel X38 register addresses - device 0 function 0 - DRAM Controller */
30 
31 #define X38_MCHBAR_LOW	0x48	/* MCH Memory Mapped Register BAR */
32 #define X38_MCHBAR_HIGH	0x4c
33 #define X38_MCHBAR_MASK	0xfffffc000ULL	/* bits 35:14 */
34 #define X38_MMR_WINDOW_SIZE	16384
35 
36 #define X38_TOM	0xa0	/* Top of Memory (16b)
37 				 *
38 				 * 15:10 reserved
39 				 *  9:0  total populated physical memory
40 				 */
41 #define X38_TOM_MASK	0x3ff	/* bits 9:0 */
42 #define X38_TOM_SHIFT 26	/* 64MiB grain */
43 
44 #define X38_ERRSTS	0xc8	/* Error Status Register (16b)
45 				 *
46 				 * 15    reserved
47 				 * 14    Isochronous TBWRR Run Behind FIFO Full
48 				 *       (ITCV)
49 				 * 13    Isochronous TBWRR Run Behind FIFO Put
50 				 *       (ITSTV)
51 				 * 12    reserved
52 				 * 11    MCH Thermal Sensor Event
53 				 *       for SMI/SCI/SERR (GTSE)
54 				 * 10    reserved
55 				 *  9    LOCK to non-DRAM Memory Flag (LCKF)
56 				 *  8    reserved
57 				 *  7    DRAM Throttle Flag (DTF)
58 				 *  6:2  reserved
59 				 *  1    Multi-bit DRAM ECC Error Flag (DMERR)
60 				 *  0    Single-bit DRAM ECC Error Flag (DSERR)
61 				 */
62 #define X38_ERRSTS_UE		0x0002
63 #define X38_ERRSTS_CE		0x0001
64 #define X38_ERRSTS_BITS	(X38_ERRSTS_UE | X38_ERRSTS_CE)
65 
66 
67 /* Intel  MMIO register space - device 0 function 0 - MMR space */
68 
69 #define X38_C0DRB	0x200	/* Channel 0 DRAM Rank Boundary (16b x 4)
70 				 *
71 				 * 15:10 reserved
72 				 *  9:0  Channel 0 DRAM Rank Boundary Address
73 				 */
74 #define X38_C1DRB	0x600	/* Channel 1 DRAM Rank Boundary (16b x 4) */
75 #define X38_DRB_MASK	0x3ff	/* bits 9:0 */
76 #define X38_DRB_SHIFT 26	/* 64MiB grain */
77 
78 #define X38_C0ECCERRLOG 0x280	/* Channel 0 ECC Error Log (64b)
79 				 *
80 				 * 63:48 Error Column Address (ERRCOL)
81 				 * 47:32 Error Row Address (ERRROW)
82 				 * 31:29 Error Bank Address (ERRBANK)
83 				 * 28:27 Error Rank Address (ERRRANK)
84 				 * 26:24 reserved
85 				 * 23:16 Error Syndrome (ERRSYND)
86 				 * 15: 2 reserved
87 				 *    1  Multiple Bit Error Status (MERRSTS)
88 				 *    0  Correctable Error Status (CERRSTS)
89 				 */
90 #define X38_C1ECCERRLOG 0x680	/* Channel 1 ECC Error Log (64b) */
91 #define X38_ECCERRLOG_CE	0x1
92 #define X38_ECCERRLOG_UE	0x2
93 #define X38_ECCERRLOG_RANK_BITS	0x18000000
94 #define X38_ECCERRLOG_SYNDROME_BITS	0xff0000
95 
96 #define X38_CAPID0 0xe0	/* see P.94 of spec for details */
97 
98 static int x38_channel_num;
99 
100 static int how_many_channel(struct pci_dev *pdev)
101 {
102 	unsigned char capid0_8b; /* 8th byte of CAPID0 */
103 
104 	pci_read_config_byte(pdev, X38_CAPID0 + 8, &capid0_8b);
105 	if (capid0_8b & 0x20) {	/* check DCD: Dual Channel Disable */
106 		edac_dbg(0, "In single channel mode\n");
107 		x38_channel_num = 1;
108 	} else {
109 		edac_dbg(0, "In dual channel mode\n");
110 		x38_channel_num = 2;
111 	}
112 
113 	return x38_channel_num;
114 }
115 
116 static unsigned long eccerrlog_syndrome(u64 log)
117 {
118 	return (log & X38_ECCERRLOG_SYNDROME_BITS) >> 16;
119 }
120 
121 static int eccerrlog_row(int channel, u64 log)
122 {
123 	return ((log & X38_ECCERRLOG_RANK_BITS) >> 27) |
124 		(channel * X38_RANKS_PER_CHANNEL);
125 }
126 
127 enum x38_chips {
128 	X38 = 0,
129 };
130 
131 struct x38_dev_info {
132 	const char *ctl_name;
133 };
134 
135 struct x38_error_info {
136 	u16 errsts;
137 	u16 errsts2;
138 	u64 eccerrlog[X38_CHANNELS];
139 };
140 
141 static const struct x38_dev_info x38_devs[] = {
142 	[X38] = {
143 		.ctl_name = "x38"},
144 };
145 
146 static struct pci_dev *mci_pdev;
147 static int x38_registered = 1;
148 
149 
150 static void x38_clear_error_info(struct mem_ctl_info *mci)
151 {
152 	struct pci_dev *pdev;
153 
154 	pdev = to_pci_dev(mci->pdev);
155 
156 	/*
157 	 * Clear any error bits.
158 	 * (Yes, we really clear bits by writing 1 to them.)
159 	 */
160 	pci_write_bits16(pdev, X38_ERRSTS, X38_ERRSTS_BITS,
161 			 X38_ERRSTS_BITS);
162 }
163 
164 static u64 x38_readq(const void __iomem *addr)
165 {
166 	return readl(addr) | (((u64)readl(addr + 4)) << 32);
167 }
168 
169 static void x38_get_and_clear_error_info(struct mem_ctl_info *mci,
170 				 struct x38_error_info *info)
171 {
172 	struct pci_dev *pdev;
173 	void __iomem *window = mci->pvt_info;
174 
175 	pdev = to_pci_dev(mci->pdev);
176 
177 	/*
178 	 * This is a mess because there is no atomic way to read all the
179 	 * registers at once and the registers can transition from CE being
180 	 * overwritten by UE.
181 	 */
182 	pci_read_config_word(pdev, X38_ERRSTS, &info->errsts);
183 	if (!(info->errsts & X38_ERRSTS_BITS))
184 		return;
185 
186 	info->eccerrlog[0] = x38_readq(window + X38_C0ECCERRLOG);
187 	if (x38_channel_num == 2)
188 		info->eccerrlog[1] = x38_readq(window + X38_C1ECCERRLOG);
189 
190 	pci_read_config_word(pdev, X38_ERRSTS, &info->errsts2);
191 
192 	/*
193 	 * If the error is the same for both reads then the first set
194 	 * of reads is valid.  If there is a change then there is a CE
195 	 * with no info and the second set of reads is valid and
196 	 * should be UE info.
197 	 */
198 	if ((info->errsts ^ info->errsts2) & X38_ERRSTS_BITS) {
199 		info->eccerrlog[0] = x38_readq(window + X38_C0ECCERRLOG);
200 		if (x38_channel_num == 2)
201 			info->eccerrlog[1] =
202 				x38_readq(window + X38_C1ECCERRLOG);
203 	}
204 
205 	x38_clear_error_info(mci);
206 }
207 
208 static void x38_process_error_info(struct mem_ctl_info *mci,
209 				struct x38_error_info *info)
210 {
211 	int channel;
212 	u64 log;
213 
214 	if (!(info->errsts & X38_ERRSTS_BITS))
215 		return;
216 
217 	if ((info->errsts ^ info->errsts2) & X38_ERRSTS_BITS) {
218 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, 0, 0, 0,
219 				     -1, -1, -1,
220 				     "UE overwrote CE", "");
221 		info->errsts = info->errsts2;
222 	}
223 
224 	for (channel = 0; channel < x38_channel_num; channel++) {
225 		log = info->eccerrlog[channel];
226 		if (log & X38_ECCERRLOG_UE) {
227 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
228 					     0, 0, 0,
229 					     eccerrlog_row(channel, log),
230 					     -1, -1,
231 					     "x38 UE", "");
232 		} else if (log & X38_ECCERRLOG_CE) {
233 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
234 					     0, 0, eccerrlog_syndrome(log),
235 					     eccerrlog_row(channel, log),
236 					     -1, -1,
237 					     "x38 CE", "");
238 		}
239 	}
240 }
241 
242 static void x38_check(struct mem_ctl_info *mci)
243 {
244 	struct x38_error_info info;
245 
246 	edac_dbg(1, "MC%d\n", mci->mc_idx);
247 	x38_get_and_clear_error_info(mci, &info);
248 	x38_process_error_info(mci, &info);
249 }
250 
251 
252 void __iomem *x38_map_mchbar(struct pci_dev *pdev)
253 {
254 	union {
255 		u64 mchbar;
256 		struct {
257 			u32 mchbar_low;
258 			u32 mchbar_high;
259 		};
260 	} u;
261 	void __iomem *window;
262 
263 	pci_read_config_dword(pdev, X38_MCHBAR_LOW, &u.mchbar_low);
264 	pci_write_config_dword(pdev, X38_MCHBAR_LOW, u.mchbar_low | 0x1);
265 	pci_read_config_dword(pdev, X38_MCHBAR_HIGH, &u.mchbar_high);
266 	u.mchbar &= X38_MCHBAR_MASK;
267 
268 	if (u.mchbar != (resource_size_t)u.mchbar) {
269 		printk(KERN_ERR
270 			"x38: mmio space beyond accessible range (0x%llx)\n",
271 			(unsigned long long)u.mchbar);
272 		return NULL;
273 	}
274 
275 	window = ioremap_nocache(u.mchbar, X38_MMR_WINDOW_SIZE);
276 	if (!window)
277 		printk(KERN_ERR "x38: cannot map mmio space at 0x%llx\n",
278 			(unsigned long long)u.mchbar);
279 
280 	return window;
281 }
282 
283 
284 static void x38_get_drbs(void __iomem *window,
285 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
286 {
287 	int i;
288 
289 	for (i = 0; i < X38_RANKS_PER_CHANNEL; i++) {
290 		drbs[0][i] = readw(window + X38_C0DRB + 2*i) & X38_DRB_MASK;
291 		drbs[1][i] = readw(window + X38_C1DRB + 2*i) & X38_DRB_MASK;
292 	}
293 }
294 
295 static bool x38_is_stacked(struct pci_dev *pdev,
296 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
297 {
298 	u16 tom;
299 
300 	pci_read_config_word(pdev, X38_TOM, &tom);
301 	tom &= X38_TOM_MASK;
302 
303 	return drbs[X38_CHANNELS - 1][X38_RANKS_PER_CHANNEL - 1] == tom;
304 }
305 
306 static unsigned long drb_to_nr_pages(
307 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL],
308 			bool stacked, int channel, int rank)
309 {
310 	int n;
311 
312 	n = drbs[channel][rank];
313 	if (rank > 0)
314 		n -= drbs[channel][rank - 1];
315 	if (stacked && (channel == 1) && drbs[channel][rank] ==
316 				drbs[channel][X38_RANKS_PER_CHANNEL - 1]) {
317 		n -= drbs[0][X38_RANKS_PER_CHANNEL - 1];
318 	}
319 
320 	n <<= (X38_DRB_SHIFT - PAGE_SHIFT);
321 	return n;
322 }
323 
324 static int x38_probe1(struct pci_dev *pdev, int dev_idx)
325 {
326 	int rc;
327 	int i, j;
328 	struct mem_ctl_info *mci = NULL;
329 	struct edac_mc_layer layers[2];
330 	u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL];
331 	bool stacked;
332 	void __iomem *window;
333 
334 	edac_dbg(0, "MC:\n");
335 
336 	window = x38_map_mchbar(pdev);
337 	if (!window)
338 		return -ENODEV;
339 
340 	x38_get_drbs(window, drbs);
341 
342 	how_many_channel(pdev);
343 
344 	/* FIXME: unconventional pvt_info usage */
345 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
346 	layers[0].size = X38_RANKS;
347 	layers[0].is_virt_csrow = true;
348 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
349 	layers[1].size = x38_channel_num;
350 	layers[1].is_virt_csrow = false;
351 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
352 	if (!mci)
353 		return -ENOMEM;
354 
355 	edac_dbg(3, "MC: init mci\n");
356 
357 	mci->pdev = &pdev->dev;
358 	mci->mtype_cap = MEM_FLAG_DDR2;
359 
360 	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
361 	mci->edac_cap = EDAC_FLAG_SECDED;
362 
363 	mci->mod_name = EDAC_MOD_STR;
364 	mci->mod_ver = X38_REVISION;
365 	mci->ctl_name = x38_devs[dev_idx].ctl_name;
366 	mci->dev_name = pci_name(pdev);
367 	mci->edac_check = x38_check;
368 	mci->ctl_page_to_phys = NULL;
369 	mci->pvt_info = window;
370 
371 	stacked = x38_is_stacked(pdev, drbs);
372 
373 	/*
374 	 * The dram rank boundary (DRB) reg values are boundary addresses
375 	 * for each DRAM rank with a granularity of 64MB.  DRB regs are
376 	 * cumulative; the last one will contain the total memory
377 	 * contained in all ranks.
378 	 */
379 	for (i = 0; i < mci->nr_csrows; i++) {
380 		unsigned long nr_pages;
381 		struct csrow_info *csrow = mci->csrows[i];
382 
383 		nr_pages = drb_to_nr_pages(drbs, stacked,
384 			i / X38_RANKS_PER_CHANNEL,
385 			i % X38_RANKS_PER_CHANNEL);
386 
387 		if (nr_pages == 0)
388 			continue;
389 
390 		for (j = 0; j < x38_channel_num; j++) {
391 			struct dimm_info *dimm = csrow->channels[j]->dimm;
392 
393 			dimm->nr_pages = nr_pages / x38_channel_num;
394 			dimm->grain = nr_pages << PAGE_SHIFT;
395 			dimm->mtype = MEM_DDR2;
396 			dimm->dtype = DEV_UNKNOWN;
397 			dimm->edac_mode = EDAC_UNKNOWN;
398 		}
399 	}
400 
401 	x38_clear_error_info(mci);
402 
403 	rc = -ENODEV;
404 	if (edac_mc_add_mc(mci)) {
405 		edac_dbg(3, "MC: failed edac_mc_add_mc()\n");
406 		goto fail;
407 	}
408 
409 	/* get this far and it's successful */
410 	edac_dbg(3, "MC: success\n");
411 	return 0;
412 
413 fail:
414 	iounmap(window);
415 	if (mci)
416 		edac_mc_free(mci);
417 
418 	return rc;
419 }
420 
421 static int __devinit x38_init_one(struct pci_dev *pdev,
422 				const struct pci_device_id *ent)
423 {
424 	int rc;
425 
426 	edac_dbg(0, "MC:\n");
427 
428 	if (pci_enable_device(pdev) < 0)
429 		return -EIO;
430 
431 	rc = x38_probe1(pdev, ent->driver_data);
432 	if (!mci_pdev)
433 		mci_pdev = pci_dev_get(pdev);
434 
435 	return rc;
436 }
437 
438 static void __devexit x38_remove_one(struct pci_dev *pdev)
439 {
440 	struct mem_ctl_info *mci;
441 
442 	edac_dbg(0, "\n");
443 
444 	mci = edac_mc_del_mc(&pdev->dev);
445 	if (!mci)
446 		return;
447 
448 	iounmap(mci->pvt_info);
449 
450 	edac_mc_free(mci);
451 }
452 
453 static DEFINE_PCI_DEVICE_TABLE(x38_pci_tbl) = {
454 	{
455 	 PCI_VEND_DEV(INTEL, X38_HB), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
456 	 X38},
457 	{
458 	 0,
459 	 }			/* 0 terminated list. */
460 };
461 
462 MODULE_DEVICE_TABLE(pci, x38_pci_tbl);
463 
464 static struct pci_driver x38_driver = {
465 	.name = EDAC_MOD_STR,
466 	.probe = x38_init_one,
467 	.remove = __devexit_p(x38_remove_one),
468 	.id_table = x38_pci_tbl,
469 };
470 
471 static int __init x38_init(void)
472 {
473 	int pci_rc;
474 
475 	edac_dbg(3, "MC:\n");
476 
477 	/* Ensure that the OPSTATE is set correctly for POLL or NMI */
478 	opstate_init();
479 
480 	pci_rc = pci_register_driver(&x38_driver);
481 	if (pci_rc < 0)
482 		goto fail0;
483 
484 	if (!mci_pdev) {
485 		x38_registered = 0;
486 		mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
487 					PCI_DEVICE_ID_INTEL_X38_HB, NULL);
488 		if (!mci_pdev) {
489 			edac_dbg(0, "x38 pci_get_device fail\n");
490 			pci_rc = -ENODEV;
491 			goto fail1;
492 		}
493 
494 		pci_rc = x38_init_one(mci_pdev, x38_pci_tbl);
495 		if (pci_rc < 0) {
496 			edac_dbg(0, "x38 init fail\n");
497 			pci_rc = -ENODEV;
498 			goto fail1;
499 		}
500 	}
501 
502 	return 0;
503 
504 fail1:
505 	pci_unregister_driver(&x38_driver);
506 
507 fail0:
508 	if (mci_pdev)
509 		pci_dev_put(mci_pdev);
510 
511 	return pci_rc;
512 }
513 
514 static void __exit x38_exit(void)
515 {
516 	edac_dbg(3, "MC:\n");
517 
518 	pci_unregister_driver(&x38_driver);
519 	if (!x38_registered) {
520 		x38_remove_one(mci_pdev);
521 		pci_dev_put(mci_pdev);
522 	}
523 }
524 
525 module_init(x38_init);
526 module_exit(x38_exit);
527 
528 MODULE_LICENSE("GPL");
529 MODULE_AUTHOR("Cluster Computing, Inc. Hitoshi Mitake");
530 MODULE_DESCRIPTION("MC support for Intel X38 memory hub controllers");
531 
532 module_param(edac_op_state, int, 0444);
533 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
534