aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/edac/i82443bxgx_edac.c
blob: 83bfe37c4bbbbabe3ec051e34aa7a6149257b203 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
/*
 * Intel 82443BX/GX (440BX/GX chipset) Memory Controller EDAC kernel
 * module (C) 2006 Tim Small
 *
 * This file may be distributed under the terms of the GNU General
 * Public License.
 *
 * Written by Tim Small <tim@buttersideup.com>, based on work by Linux
 * Networx, Thayne Harbaugh, Dan Hollis <goemon at anime dot net> and
 * others.
 *
 * 440GX fix by Jason Uhlenkott <juhlenko@akamai.com>.
 *
 * Written with reference to 82443BX Host Bridge Datasheet:
 * http://www.intel.com/design/chipsets/440/documentation.htm
 * references to this document given in [].
 *
 * This module doesn't support the 440LX, but it may be possible to
 * make it do so (the 440LX's register definitions are different, but
 * not completely so - I haven't studied them in enough detail to know
 * how easy this would be).
 */

#include <linux/module.h>
#include <linux/init.h>

#include <linux/pci.h>
#include <linux/pci_ids.h>

#include <linux/slab.h>

#include "edac_core.h"

#define I82443_REVISION	"0.1"

#define EDAC_MOD_STR    "i82443bxgx_edac"

/* The 82443BX supports SDRAM, or EDO (EDO for mobile only), "Memory
 * Size: 8 MB to 512 MB (1GB with Registered DIMMs) with eight memory
 * rows" "The 82443BX supports multiple-bit error detection and
 * single-bit error correction when ECC mode is enabled and
 * single/multi-bit error detection when correction is disabled.
 * During writes to the DRAM, the 82443BX generates ECC for the data
 * on a QWord basis. Partial QWord writes require a read-modify-write
 * cycle when ECC is enabled."
*/

/* "Additionally, the 82443BX ensures that the data is corrected in
 * main memory so that accumulation of errors is prevented. Another
 * error within the same QWord would result in a double-bit error
 * which is unrecoverable. This is known as hardware scrubbing since
 * it requires no software intervention to correct the data in memory."
 */

/* [Also see page 100 (section 4.3), "DRAM Interface"]
 * [Also see page 112 (section 4.6.1.4), ECC]
 */

#define I82443BXGX_NR_CSROWS 8
#define I82443BXGX_NR_CHANS  1
#define I82443BXGX_NR_DIMMS  4

/* 82443 PCI Device 0 */
#define I82443BXGX_NBXCFG 0x50	/* 32bit register starting at this PCI
				 * config space offset */
#define I82443BXGX_NBXCFG_OFFSET_NON_ECCROW 24	/* Array of bits, zero if
						 * row is non-ECC */
#define I82443BXGX_NBXCFG_OFFSET_DRAM_FREQ 12	/* 2 bits,00=100MHz,10=66 MHz */

#define I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY 7	/* 2 bits:       */
#define I82443BXGX_NBXCFG_INTEGRITY_NONE   0x0	/* 00 = Non-ECC */
#define I82443BXGX_NBXCFG_INTEGRITY_EC     0x1	/* 01 = EC (only) */
#define I82443BXGX_NBXCFG_INTEGRITY_ECC    0x2	/* 10 = ECC */
#define I82443BXGX_NBXCFG_INTEGRITY_SCRUB  0x3	/* 11 = ECC + HW Scrub */

#define I82443BXGX_NBXCFG_OFFSET_ECC_DIAG_ENABLE  6

/* 82443 PCI Device 0 */
#define I82443BXGX_EAP   0x80	/* 32bit register starting at this PCI
				 * config space offset, Error Address
				 * Pointer Register */
#define I82443BXGX_EAP_OFFSET_EAP  12	/* High 20 bits of error address */
#define I82443BXGX_EAP_OFFSET_MBE  BIT(1)	/* Err at EAP was multi-bit (W1TC) */
#define I82443BXGX_EAP_OFFSET_SBE  BIT(0)	/* Err at EAP was single-bit (W1TC) */

#define I82443BXGX_ERRCMD  0x90	/* 8bit register starting at this PCI
				 * config space offset. */
#define I82443BXGX_ERRCMD_OFFSET_SERR_ON_MBE BIT(1)	/* 1 = enable */
#define I82443BXGX_ERRCMD_OFFSET_SERR_ON_SBE BIT(0)	/* 1 = enable */

#define I82443BXGX_ERRSTS  0x91	/* 16bit register starting at this PCI
				 * config space offset. */
#define I82443BXGX_ERRSTS_OFFSET_MBFRE 5	/* 3 bits - first err row multibit */
#define I82443BXGX_ERRSTS_OFFSET_MEF   BIT(4)	/* 1 = MBE occurred */
#define I82443BXGX_ERRSTS_OFFSET_SBFRE 1	/* 3 bits - first err row singlebit */
#define I82443BXGX_ERRSTS_OFFSET_SEF   BIT(0)	/* 1 = SBE occurred */

#define I82443BXGX_DRAMC 0x57	/* 8bit register starting at this PCI
				 * config space offset. */
#define I82443BXGX_DRAMC_OFFSET_DT 3	/* 2 bits, DRAM Type */
#define I82443BXGX_DRAMC_DRAM_IS_EDO 0	/* 00 = EDO */
#define I82443BXGX_DRAMC_DRAM_IS_SDRAM 1	/* 01 = SDRAM */
#define I82443BXGX_DRAMC_DRAM_IS_RSDRAM 2	/* 10 = Registered SDRAM */

#define I82443BXGX_DRB 0x60	/* 8x 8bit registers starting at this PCI
				 * config space offset. */

/* FIXME - don't poll when ECC disabled? */

struct i82443bxgx_edacmc_error_info {
	u32 eap;
};

static struct edac_pci_ctl_info *i82443bxgx_pci;

static void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
				struct i82443bxgx_edacmc_error_info
				*info)
{
	struct pci_dev *pdev;
	pdev = to_pci_dev(mci->dev);
	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
		/* Clear error to allow next error to be reported [p.61] */
		pci_write_bits32(pdev, I82443BXGX_EAP,
				 I82443BXGX_EAP_OFFSET_SBE,
				 I82443BXGX_EAP_OFFSET_SBE);

	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
		/* Clear error to allow next error to be reported [p.61] */
		pci_write_bits32(pdev, I82443BXGX_EAP,
				 I82443BXGX_EAP_OFFSET_MBE,
				 I82443BXGX_EAP_OFFSET_MBE);
}

static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
						struct
						i82443bxgx_edacmc_error_info
						*info, int handle_errors)
{
	int error_found = 0;
	u32 eapaddr, page, pageoffset;

	/* bits 30:12 hold the 4kb block in which the error occurred
	 * [p.61] */
	eapaddr = (info->eap & 0xfffff000);
	page = eapaddr >> PAGE_SHIFT;
	pageoffset = eapaddr - (page << PAGE_SHIFT);

	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
		error_found = 1;
		if (handle_errors)
			edac_mc_handle_ce(mci, page, pageoffset,
				/* 440BX/GX don't make syndrome information
				 * available */
				0, edac_mc_find_csrow_by_page(mci, page), 0,
				mci->ctl_name);
	}

	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
		error_found = 1;
		if (handle_errors)
			edac_mc_handle_ue(mci, page, pageoffset,
					edac_mc_find_csrow_by_page(mci, page),
					mci->ctl_name);
	}

	return error_found;
}

static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
{
	struct i82443bxgx_edacmc_error_info info;

	debugf1("MC%d: " __FILE__ ": %s()\n", mci->mc_idx, __func__);
	i82443bxgx_edacmc_get_error_info(mci, &info);
	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
}

static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
				struct pci_dev *pdev,
				enum edac_type edac_mode,
				enum mem_type mtype)
{
	struct csrow_info *csrow;
	int index;
	u8 drbar, dramc;
	u32 row_base, row_high_limit, row_high_limit_last;

	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
	row_high_limit_last = 0;
	for (index = 0; index < mci->nr_csrows; index++) {
		csrow = &mci->csrows[index];
		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
		debugf1("MC%d: " __FILE__ ": %s() Row=%d DRB = %#0x\n",
			mci->mc_idx, __func__, index, drbar);
		row_high_limit = ((u32) drbar << 23);
		/* find the DRAM Chip Select Base address and mask */
		debugf1("MC%d: " __FILE__ ": %s() Row=%d, "
			"Boundry Address=%#0x, Last = %#0x \n",
			mci->mc_idx, __func__, index, row_high_limit,
			row_high_limit_last);

		/* 440GX goes to 2GB, represented with a DRB of 0. */
		if (row_high_limit_last && !row_high_limit)
			row_high_limit = 1UL << 31;

		/* This row is empty [p.49] */
		if (row_high_limit == row_high_limit_last)
			continue;
		row_base = row_high_limit_last;
		csrow->first_page = row_base >> PAGE_SHIFT;
		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
		/* EAP reports in 4kilobyte granularity [61] */
		csrow->grain = 1 << 12;
		csrow->mtype = mtype;
		/* I don't think 440BX can tell you device type? FIXME? */
		csrow->dtype = DEV_UNKNOWN;
		/* Mode is global to all rows on 440BX */
		csrow->edac_mode = edac_mode;
		row_high_limit_last = row_high_limit;
	}
}

static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
{
	struct mem_ctl_info *mci;
	u8 dramc;
	u32 nbxcfg, ecc_mode;
	enum mem_type mtype;
	enum edac_type edac_mode;

	debugf0("MC: " __FILE__ ": %s()\n", __func__);

	/* Something is really hosed if PCI config space reads from
	 * the MC aren't working.
	 */
	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
		return -EIO;

	mci = edac_mc_alloc(0, I82443BXGX_NR_CSROWS, I82443BXGX_NR_CHANS, 0);

	if (mci == NULL)
		return -ENOMEM;

	debugf0("MC: " __FILE__ ": %s(): mci = %p\n", __func__, mci);
	mci->dev = &pdev->dev;
	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
	case I82443BXGX_DRAMC_DRAM_IS_EDO:
		mtype = MEM_EDO;
		break;
	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
		mtype = MEM_SDR;
		break;
	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
		mtype = MEM_RDR;
		break;
	default:
		debugf0("Unknown/reserved DRAM type value "
			"in DRAMC register!\n");
		mtype = -MEM_UNKNOWN;
	}

	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
		mci->edac_cap = mci->edac_ctl_cap;
	else
		mci->edac_cap = EDAC_FLAG_NONE;

	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
		(BIT(0) | BIT(1)));

	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
		? SCRUB_HW_SRC : SCRUB_NONE;

	switch (ecc_mode) {
	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
		edac_mode = EDAC_NONE;
		break;
	case I82443BXGX_NBXCFG_INTEGRITY_EC:
		edac_mode = EDAC_EC;
		break;
	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
		edac_mode = EDAC_SECDED;
		break;
	default:
		debugf0("%s(): Unknown/reserved ECC state "
			"in NBXCFG register!\n", __func__);
		edac_mode = EDAC_UNKNOWN;
		break;
	}

	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);

	/* Many BIOSes don't clear error flags on boot, so do this
	 * here, or we get "phantom" errors occuring at module-load
	 * time. */
	pci_write_bits32(pdev, I82443BXGX_EAP,
			(I82443BXGX_EAP_OFFSET_SBE |
				I82443BXGX_EAP_OFFSET_MBE),
			(I82443BXGX_EAP_OFFSET_SBE |
				I82443BXGX_EAP_OFFSET_MBE));

	mci->mod_name = EDAC_MOD_STR;
	mci->mod_ver = I82443_REVISION;
	mci->ctl_name = "I82443BXGX";
	mci->dev_name = pci_name(pdev);
	mci->edac_check = i82443bxgx_edacmc_check;
	mci->ctl_page_to_phys = NULL;

	if (edac_mc_add_mc(mci)) {
		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
		goto fail;
	}

	/* allocating generic PCI control info */
	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
	if (!i82443bxgx_pci) {
		printk(KERN_WARNING
			"%s(): Unable to create PCI control\n",
			__func__);
		printk(KERN_WARNING
			"%s(): PCI error report via EDAC not setup\n",
			__func__);
	}

	debugf3("MC: " __FILE__ ": %s(): success\n", __func__);
	return 0;

fail:
	edac_mc_free(mci);
	return -ENODEV;
}

EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);

/* returns count (>= 0), or negative on error */
static int __devinit i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
						const struct pci_device_id *ent)
{
	debugf0("MC: " __FILE__ ": %s()\n", __func__);

	/* don't need to call pci_device_enable() */
	return i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
}

static void __devexit i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
{
	struct mem_ctl_info *mci;

	debugf0(__FILE__ ": %s()\n", __func__);

	if (i82443bxgx_pci)
		edac_pci_release_generic_ctl(i82443bxgx_pci);

	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
		return;

	edac_mc_free(mci);
}

EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);

static const struct pci_device_id i82443bxgx_pci_tbl[] __devinitdata = {
	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
	{0,}			/* 0 terminated list. */
};

MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);

static struct pci_driver i82443bxgx_edacmc_driver = {
	.name = EDAC_MOD_STR,
	.probe = i82443bxgx_edacmc_init_one,
	.remove = __devexit_p(i82443bxgx_edacmc_remove_one),
	.id_table = i82443bxgx_pci_tbl,
};

static int __init i82443bxgx_edacmc_init(void)
{
	return pci_register_driver(&i82443bxgx_edacmc_driver);
}

static void __exit i82443bxgx_edacmc_exit(void)
{
	pci_unregister_driver(&i82443bxgx_edacmc_driver);
}

module_init(i82443bxgx_edacmc_init);
module_exit(i82443bxgx_edacmc_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");