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 
how_many_channel(struct pci_dev * pdev)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 		debugf0("In single channel mode.\n");
107 		x38_channel_num = 1;
108 	} else {
109 		debugf0("In dual channel mode.\n");
110 		x38_channel_num = 2;
111 	}
112 
113 	return x38_channel_num;
114 }
115 
eccerrlog_syndrome(u64 log)116 static unsigned long eccerrlog_syndrome(u64 log)
117 {
118 	return (log & X38_ECCERRLOG_SYNDROME_BITS) >> 16;
119 }
120 
eccerrlog_row(int channel,u64 log)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 
x38_clear_error_info(struct mem_ctl_info * mci)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->dev);
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 
x38_readq(const void __iomem * addr)164 static u64 x38_readq(const void __iomem *addr)
165 {
166 	return readl(addr) | (((u64)readl(addr + 4)) << 32);
167 }
168 
x38_get_and_clear_error_info(struct mem_ctl_info * mci,struct x38_error_info * info)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->dev);
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 
x38_process_error_info(struct mem_ctl_info * mci,struct x38_error_info * info)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_ce_no_info(mci, "UE overwrote CE");
219 		info->errsts = info->errsts2;
220 	}
221 
222 	for (channel = 0; channel < x38_channel_num; channel++) {
223 		log = info->eccerrlog[channel];
224 		if (log & X38_ECCERRLOG_UE) {
225 			edac_mc_handle_ue(mci, 0, 0,
226 				eccerrlog_row(channel, log), "x38 UE");
227 		} else if (log & X38_ECCERRLOG_CE) {
228 			edac_mc_handle_ce(mci, 0, 0,
229 				eccerrlog_syndrome(log),
230 				eccerrlog_row(channel, log), 0, "x38 CE");
231 		}
232 	}
233 }
234 
x38_check(struct mem_ctl_info * mci)235 static void x38_check(struct mem_ctl_info *mci)
236 {
237 	struct x38_error_info info;
238 
239 	debugf1("MC%d: %s()\n", mci->mc_idx, __func__);
240 	x38_get_and_clear_error_info(mci, &info);
241 	x38_process_error_info(mci, &info);
242 }
243 
244 
x38_map_mchbar(struct pci_dev * pdev)245 void __iomem *x38_map_mchbar(struct pci_dev *pdev)
246 {
247 	union {
248 		u64 mchbar;
249 		struct {
250 			u32 mchbar_low;
251 			u32 mchbar_high;
252 		};
253 	} u;
254 	void __iomem *window;
255 
256 	pci_read_config_dword(pdev, X38_MCHBAR_LOW, &u.mchbar_low);
257 	pci_write_config_dword(pdev, X38_MCHBAR_LOW, u.mchbar_low | 0x1);
258 	pci_read_config_dword(pdev, X38_MCHBAR_HIGH, &u.mchbar_high);
259 	u.mchbar &= X38_MCHBAR_MASK;
260 
261 	if (u.mchbar != (resource_size_t)u.mchbar) {
262 		printk(KERN_ERR
263 			"x38: mmio space beyond accessible range (0x%llx)\n",
264 			(unsigned long long)u.mchbar);
265 		return NULL;
266 	}
267 
268 	window = ioremap_nocache(u.mchbar, X38_MMR_WINDOW_SIZE);
269 	if (!window)
270 		printk(KERN_ERR "x38: cannot map mmio space at 0x%llx\n",
271 			(unsigned long long)u.mchbar);
272 
273 	return window;
274 }
275 
276 
x38_get_drbs(void __iomem * window,u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])277 static void x38_get_drbs(void __iomem *window,
278 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
279 {
280 	int i;
281 
282 	for (i = 0; i < X38_RANKS_PER_CHANNEL; i++) {
283 		drbs[0][i] = readw(window + X38_C0DRB + 2*i) & X38_DRB_MASK;
284 		drbs[1][i] = readw(window + X38_C1DRB + 2*i) & X38_DRB_MASK;
285 	}
286 }
287 
x38_is_stacked(struct pci_dev * pdev,u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])288 static bool x38_is_stacked(struct pci_dev *pdev,
289 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
290 {
291 	u16 tom;
292 
293 	pci_read_config_word(pdev, X38_TOM, &tom);
294 	tom &= X38_TOM_MASK;
295 
296 	return drbs[X38_CHANNELS - 1][X38_RANKS_PER_CHANNEL - 1] == tom;
297 }
298 
drb_to_nr_pages(u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL],bool stacked,int channel,int rank)299 static unsigned long drb_to_nr_pages(
300 			u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL],
301 			bool stacked, int channel, int rank)
302 {
303 	int n;
304 
305 	n = drbs[channel][rank];
306 	if (rank > 0)
307 		n -= drbs[channel][rank - 1];
308 	if (stacked && (channel == 1) && drbs[channel][rank] ==
309 				drbs[channel][X38_RANKS_PER_CHANNEL - 1]) {
310 		n -= drbs[0][X38_RANKS_PER_CHANNEL - 1];
311 	}
312 
313 	n <<= (X38_DRB_SHIFT - PAGE_SHIFT);
314 	return n;
315 }
316 
x38_probe1(struct pci_dev * pdev,int dev_idx)317 static int x38_probe1(struct pci_dev *pdev, int dev_idx)
318 {
319 	int rc;
320 	int i;
321 	struct mem_ctl_info *mci = NULL;
322 	unsigned long last_page;
323 	u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL];
324 	bool stacked;
325 	void __iomem *window;
326 
327 	debugf0("MC: %s()\n", __func__);
328 
329 	window = x38_map_mchbar(pdev);
330 	if (!window)
331 		return -ENODEV;
332 
333 	x38_get_drbs(window, drbs);
334 
335 	how_many_channel(pdev);
336 
337 	/* FIXME: unconventional pvt_info usage */
338 	mci = edac_mc_alloc(0, X38_RANKS, x38_channel_num, 0);
339 	if (!mci)
340 		return -ENOMEM;
341 
342 	debugf3("MC: %s(): init mci\n", __func__);
343 
344 	mci->dev = &pdev->dev;
345 	mci->mtype_cap = MEM_FLAG_DDR2;
346 
347 	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
348 	mci->edac_cap = EDAC_FLAG_SECDED;
349 
350 	mci->mod_name = EDAC_MOD_STR;
351 	mci->mod_ver = X38_REVISION;
352 	mci->ctl_name = x38_devs[dev_idx].ctl_name;
353 	mci->dev_name = pci_name(pdev);
354 	mci->edac_check = x38_check;
355 	mci->ctl_page_to_phys = NULL;
356 	mci->pvt_info = window;
357 
358 	stacked = x38_is_stacked(pdev, drbs);
359 
360 	/*
361 	 * The dram rank boundary (DRB) reg values are boundary addresses
362 	 * for each DRAM rank with a granularity of 64MB.  DRB regs are
363 	 * cumulative; the last one will contain the total memory
364 	 * contained in all ranks.
365 	 */
366 	last_page = -1UL;
367 	for (i = 0; i < mci->nr_csrows; i++) {
368 		unsigned long nr_pages;
369 		struct csrow_info *csrow = &mci->csrows[i];
370 
371 		nr_pages = drb_to_nr_pages(drbs, stacked,
372 			i / X38_RANKS_PER_CHANNEL,
373 			i % X38_RANKS_PER_CHANNEL);
374 
375 		if (nr_pages == 0) {
376 			csrow->mtype = MEM_EMPTY;
377 			continue;
378 		}
379 
380 		csrow->first_page = last_page + 1;
381 		last_page += nr_pages;
382 		csrow->last_page = last_page;
383 		csrow->nr_pages = nr_pages;
384 
385 		csrow->grain = nr_pages << PAGE_SHIFT;
386 		csrow->mtype = MEM_DDR2;
387 		csrow->dtype = DEV_UNKNOWN;
388 		csrow->edac_mode = EDAC_UNKNOWN;
389 	}
390 
391 	x38_clear_error_info(mci);
392 
393 	rc = -ENODEV;
394 	if (edac_mc_add_mc(mci)) {
395 		debugf3("MC: %s(): failed edac_mc_add_mc()\n", __func__);
396 		goto fail;
397 	}
398 
399 	/* get this far and it's successful */
400 	debugf3("MC: %s(): success\n", __func__);
401 	return 0;
402 
403 fail:
404 	iounmap(window);
405 	if (mci)
406 		edac_mc_free(mci);
407 
408 	return rc;
409 }
410 
x38_init_one(struct pci_dev * pdev,const struct pci_device_id * ent)411 static int __devinit x38_init_one(struct pci_dev *pdev,
412 				const struct pci_device_id *ent)
413 {
414 	int rc;
415 
416 	debugf0("MC: %s()\n", __func__);
417 
418 	if (pci_enable_device(pdev) < 0)
419 		return -EIO;
420 
421 	rc = x38_probe1(pdev, ent->driver_data);
422 	if (!mci_pdev)
423 		mci_pdev = pci_dev_get(pdev);
424 
425 	return rc;
426 }
427 
x38_remove_one(struct pci_dev * pdev)428 static void __devexit x38_remove_one(struct pci_dev *pdev)
429 {
430 	struct mem_ctl_info *mci;
431 
432 	debugf0("%s()\n", __func__);
433 
434 	mci = edac_mc_del_mc(&pdev->dev);
435 	if (!mci)
436 		return;
437 
438 	iounmap(mci->pvt_info);
439 
440 	edac_mc_free(mci);
441 }
442 
443 static DEFINE_PCI_DEVICE_TABLE(x38_pci_tbl) = {
444 	{
445 	 PCI_VEND_DEV(INTEL, X38_HB), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
446 	 X38},
447 	{
448 	 0,
449 	 }			/* 0 terminated list. */
450 };
451 
452 MODULE_DEVICE_TABLE(pci, x38_pci_tbl);
453 
454 static struct pci_driver x38_driver = {
455 	.name = EDAC_MOD_STR,
456 	.probe = x38_init_one,
457 	.remove = __devexit_p(x38_remove_one),
458 	.id_table = x38_pci_tbl,
459 };
460 
x38_init(void)461 static int __init x38_init(void)
462 {
463 	int pci_rc;
464 
465 	debugf3("MC: %s()\n", __func__);
466 
467 	/* Ensure that the OPSTATE is set correctly for POLL or NMI */
468 	opstate_init();
469 
470 	pci_rc = pci_register_driver(&x38_driver);
471 	if (pci_rc < 0)
472 		goto fail0;
473 
474 	if (!mci_pdev) {
475 		x38_registered = 0;
476 		mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
477 					PCI_DEVICE_ID_INTEL_X38_HB, NULL);
478 		if (!mci_pdev) {
479 			debugf0("x38 pci_get_device fail\n");
480 			pci_rc = -ENODEV;
481 			goto fail1;
482 		}
483 
484 		pci_rc = x38_init_one(mci_pdev, x38_pci_tbl);
485 		if (pci_rc < 0) {
486 			debugf0("x38 init fail\n");
487 			pci_rc = -ENODEV;
488 			goto fail1;
489 		}
490 	}
491 
492 	return 0;
493 
494 fail1:
495 	pci_unregister_driver(&x38_driver);
496 
497 fail0:
498 	if (mci_pdev)
499 		pci_dev_put(mci_pdev);
500 
501 	return pci_rc;
502 }
503 
x38_exit(void)504 static void __exit x38_exit(void)
505 {
506 	debugf3("MC: %s()\n", __func__);
507 
508 	pci_unregister_driver(&x38_driver);
509 	if (!x38_registered) {
510 		x38_remove_one(mci_pdev);
511 		pci_dev_put(mci_pdev);
512 	}
513 }
514 
515 module_init(x38_init);
516 module_exit(x38_exit);
517 
518 MODULE_LICENSE("GPL");
519 MODULE_AUTHOR("Cluster Computing, Inc. Hitoshi Mitake");
520 MODULE_DESCRIPTION("MC support for Intel X38 memory hub controllers");
521 
522 module_param(edac_op_state, int, 0444);
523 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
524