xref: /linux/drivers/edac/i82443bxgx_edac.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * Intel 82443BX/GX (440BX/GX chipset) Memory Controller EDAC kernel
3  * module (C) 2006 Tim Small
4  *
5  * This file may be distributed under the terms of the GNU General
6  * Public License.
7  *
8  * Written by Tim Small <tim@buttersideup.com>, based on work by Linux
9  * Networx, Thayne Harbaugh, Dan Hollis <goemon at anime dot net> and
10  * others.
11  *
12  * 440GX fix by Jason Uhlenkott <juhlenko@akamai.com>.
13  *
14  * Written with reference to 82443BX Host Bridge Datasheet:
15  * http://www.intel.com/design/chipsets/440/documentation.htm
16  * references to this document given in [].
17  *
18  * This module doesn't support the 440LX, but it may be possible to
19  * make it do so (the 440LX's register definitions are different, but
20  * not completely so - I haven't studied them in enough detail to know
21  * how easy this would be).
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 
27 #include <linux/pci.h>
28 #include <linux/pci_ids.h>
29 
30 #include <linux/slab.h>
31 
32 #include <linux/edac.h>
33 #include "edac_core.h"
34 
35 #define I82443_REVISION	"0.1"
36 
37 #define EDAC_MOD_STR    "i82443bxgx_edac"
38 
39 /* The 82443BX supports SDRAM, or EDO (EDO for mobile only), "Memory
40  * Size: 8 MB to 512 MB (1GB with Registered DIMMs) with eight memory
41  * rows" "The 82443BX supports multiple-bit error detection and
42  * single-bit error correction when ECC mode is enabled and
43  * single/multi-bit error detection when correction is disabled.
44  * During writes to the DRAM, the 82443BX generates ECC for the data
45  * on a QWord basis. Partial QWord writes require a read-modify-write
46  * cycle when ECC is enabled."
47 */
48 
49 /* "Additionally, the 82443BX ensures that the data is corrected in
50  * main memory so that accumulation of errors is prevented. Another
51  * error within the same QWord would result in a double-bit error
52  * which is unrecoverable. This is known as hardware scrubbing since
53  * it requires no software intervention to correct the data in memory."
54  */
55 
56 /* [Also see page 100 (section 4.3), "DRAM Interface"]
57  * [Also see page 112 (section 4.6.1.4), ECC]
58  */
59 
60 #define I82443BXGX_NR_CSROWS 8
61 #define I82443BXGX_NR_CHANS  1
62 #define I82443BXGX_NR_DIMMS  4
63 
64 /* 82443 PCI Device 0 */
65 #define I82443BXGX_NBXCFG 0x50	/* 32bit register starting at this PCI
66 				 * config space offset */
67 #define I82443BXGX_NBXCFG_OFFSET_NON_ECCROW 24	/* Array of bits, zero if
68 						 * row is non-ECC */
69 #define I82443BXGX_NBXCFG_OFFSET_DRAM_FREQ 12	/* 2 bits,00=100MHz,10=66 MHz */
70 
71 #define I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY 7	/* 2 bits:       */
72 #define I82443BXGX_NBXCFG_INTEGRITY_NONE   0x0	/* 00 = Non-ECC */
73 #define I82443BXGX_NBXCFG_INTEGRITY_EC     0x1	/* 01 = EC (only) */
74 #define I82443BXGX_NBXCFG_INTEGRITY_ECC    0x2	/* 10 = ECC */
75 #define I82443BXGX_NBXCFG_INTEGRITY_SCRUB  0x3	/* 11 = ECC + HW Scrub */
76 
77 #define I82443BXGX_NBXCFG_OFFSET_ECC_DIAG_ENABLE  6
78 
79 /* 82443 PCI Device 0 */
80 #define I82443BXGX_EAP   0x80	/* 32bit register starting at this PCI
81 				 * config space offset, Error Address
82 				 * Pointer Register */
83 #define I82443BXGX_EAP_OFFSET_EAP  12	/* High 20 bits of error address */
84 #define I82443BXGX_EAP_OFFSET_MBE  BIT(1)	/* Err at EAP was multi-bit (W1TC) */
85 #define I82443BXGX_EAP_OFFSET_SBE  BIT(0)	/* Err at EAP was single-bit (W1TC) */
86 
87 #define I82443BXGX_ERRCMD  0x90	/* 8bit register starting at this PCI
88 				 * config space offset. */
89 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_MBE BIT(1)	/* 1 = enable */
90 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_SBE BIT(0)	/* 1 = enable */
91 
92 #define I82443BXGX_ERRSTS  0x91	/* 16bit register starting at this PCI
93 				 * config space offset. */
94 #define I82443BXGX_ERRSTS_OFFSET_MBFRE 5	/* 3 bits - first err row multibit */
95 #define I82443BXGX_ERRSTS_OFFSET_MEF   BIT(4)	/* 1 = MBE occurred */
96 #define I82443BXGX_ERRSTS_OFFSET_SBFRE 1	/* 3 bits - first err row singlebit */
97 #define I82443BXGX_ERRSTS_OFFSET_SEF   BIT(0)	/* 1 = SBE occurred */
98 
99 #define I82443BXGX_DRAMC 0x57	/* 8bit register starting at this PCI
100 				 * config space offset. */
101 #define I82443BXGX_DRAMC_OFFSET_DT 3	/* 2 bits, DRAM Type */
102 #define I82443BXGX_DRAMC_DRAM_IS_EDO 0	/* 00 = EDO */
103 #define I82443BXGX_DRAMC_DRAM_IS_SDRAM 1	/* 01 = SDRAM */
104 #define I82443BXGX_DRAMC_DRAM_IS_RSDRAM 2	/* 10 = Registered SDRAM */
105 
106 #define I82443BXGX_DRB 0x60	/* 8x 8bit registers starting at this PCI
107 				 * config space offset. */
108 
109 /* FIXME - don't poll when ECC disabled? */
110 
111 struct i82443bxgx_edacmc_error_info {
112 	u32 eap;
113 };
114 
115 static struct edac_pci_ctl_info *i82443bxgx_pci;
116 
117 static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
118 					 * already registered driver
119 					 */
120 
121 static int i82443bxgx_registered = 1;
122 
123 static void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
124 				struct i82443bxgx_edacmc_error_info
125 				*info)
126 {
127 	struct pci_dev *pdev;
128 	pdev = to_pci_dev(mci->dev);
129 	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
130 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
131 		/* Clear error to allow next error to be reported [p.61] */
132 		pci_write_bits32(pdev, I82443BXGX_EAP,
133 				 I82443BXGX_EAP_OFFSET_SBE,
134 				 I82443BXGX_EAP_OFFSET_SBE);
135 
136 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
137 		/* Clear error to allow next error to be reported [p.61] */
138 		pci_write_bits32(pdev, I82443BXGX_EAP,
139 				 I82443BXGX_EAP_OFFSET_MBE,
140 				 I82443BXGX_EAP_OFFSET_MBE);
141 }
142 
143 static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
144 						struct
145 						i82443bxgx_edacmc_error_info
146 						*info, int handle_errors)
147 {
148 	int error_found = 0;
149 	u32 eapaddr, page, pageoffset;
150 
151 	/* bits 30:12 hold the 4kb block in which the error occurred
152 	 * [p.61] */
153 	eapaddr = (info->eap & 0xfffff000);
154 	page = eapaddr >> PAGE_SHIFT;
155 	pageoffset = eapaddr - (page << PAGE_SHIFT);
156 
157 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
158 		error_found = 1;
159 		if (handle_errors)
160 			edac_mc_handle_ce(mci, page, pageoffset,
161 				/* 440BX/GX don't make syndrome information
162 				 * available */
163 				0, edac_mc_find_csrow_by_page(mci, page), 0,
164 				mci->ctl_name);
165 	}
166 
167 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
168 		error_found = 1;
169 		if (handle_errors)
170 			edac_mc_handle_ue(mci, page, pageoffset,
171 					edac_mc_find_csrow_by_page(mci, page),
172 					mci->ctl_name);
173 	}
174 
175 	return error_found;
176 }
177 
178 static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
179 {
180 	struct i82443bxgx_edacmc_error_info info;
181 
182 	debugf1("MC%d: " __FILE__ ": %s()\n", mci->mc_idx, __func__);
183 	i82443bxgx_edacmc_get_error_info(mci, &info);
184 	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
185 }
186 
187 static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
188 				struct pci_dev *pdev,
189 				enum edac_type edac_mode,
190 				enum mem_type mtype)
191 {
192 	struct csrow_info *csrow;
193 	int index;
194 	u8 drbar, dramc;
195 	u32 row_base, row_high_limit, row_high_limit_last;
196 
197 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
198 	row_high_limit_last = 0;
199 	for (index = 0; index < mci->nr_csrows; index++) {
200 		csrow = &mci->csrows[index];
201 		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
202 		debugf1("MC%d: " __FILE__ ": %s() Row=%d DRB = %#0x\n",
203 			mci->mc_idx, __func__, index, drbar);
204 		row_high_limit = ((u32) drbar << 23);
205 		/* find the DRAM Chip Select Base address and mask */
206 		debugf1("MC%d: " __FILE__ ": %s() Row=%d, "
207 			"Boundry Address=%#0x, Last = %#0x \n",
208 			mci->mc_idx, __func__, index, row_high_limit,
209 			row_high_limit_last);
210 
211 		/* 440GX goes to 2GB, represented with a DRB of 0. */
212 		if (row_high_limit_last && !row_high_limit)
213 			row_high_limit = 1UL << 31;
214 
215 		/* This row is empty [p.49] */
216 		if (row_high_limit == row_high_limit_last)
217 			continue;
218 		row_base = row_high_limit_last;
219 		csrow->first_page = row_base >> PAGE_SHIFT;
220 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
221 		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
222 		/* EAP reports in 4kilobyte granularity [61] */
223 		csrow->grain = 1 << 12;
224 		csrow->mtype = mtype;
225 		/* I don't think 440BX can tell you device type? FIXME? */
226 		csrow->dtype = DEV_UNKNOWN;
227 		/* Mode is global to all rows on 440BX */
228 		csrow->edac_mode = edac_mode;
229 		row_high_limit_last = row_high_limit;
230 	}
231 }
232 
233 static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
234 {
235 	struct mem_ctl_info *mci;
236 	u8 dramc;
237 	u32 nbxcfg, ecc_mode;
238 	enum mem_type mtype;
239 	enum edac_type edac_mode;
240 
241 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
242 
243 	/* Something is really hosed if PCI config space reads from
244 	 * the MC aren't working.
245 	 */
246 	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
247 		return -EIO;
248 
249 	mci = edac_mc_alloc(0, I82443BXGX_NR_CSROWS, I82443BXGX_NR_CHANS, 0);
250 
251 	if (mci == NULL)
252 		return -ENOMEM;
253 
254 	debugf0("MC: " __FILE__ ": %s(): mci = %p\n", __func__, mci);
255 	mci->dev = &pdev->dev;
256 	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
257 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
258 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
259 	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
260 	case I82443BXGX_DRAMC_DRAM_IS_EDO:
261 		mtype = MEM_EDO;
262 		break;
263 	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
264 		mtype = MEM_SDR;
265 		break;
266 	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
267 		mtype = MEM_RDR;
268 		break;
269 	default:
270 		debugf0("Unknown/reserved DRAM type value "
271 			"in DRAMC register!\n");
272 		mtype = -MEM_UNKNOWN;
273 	}
274 
275 	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
276 		mci->edac_cap = mci->edac_ctl_cap;
277 	else
278 		mci->edac_cap = EDAC_FLAG_NONE;
279 
280 	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
281 	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
282 	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
283 		(BIT(0) | BIT(1)));
284 
285 	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
286 		? SCRUB_HW_SRC : SCRUB_NONE;
287 
288 	switch (ecc_mode) {
289 	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
290 		edac_mode = EDAC_NONE;
291 		break;
292 	case I82443BXGX_NBXCFG_INTEGRITY_EC:
293 		edac_mode = EDAC_EC;
294 		break;
295 	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
296 	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
297 		edac_mode = EDAC_SECDED;
298 		break;
299 	default:
300 		debugf0("%s(): Unknown/reserved ECC state "
301 			"in NBXCFG register!\n", __func__);
302 		edac_mode = EDAC_UNKNOWN;
303 		break;
304 	}
305 
306 	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
307 
308 	/* Many BIOSes don't clear error flags on boot, so do this
309 	 * here, or we get "phantom" errors occuring at module-load
310 	 * time. */
311 	pci_write_bits32(pdev, I82443BXGX_EAP,
312 			(I82443BXGX_EAP_OFFSET_SBE |
313 				I82443BXGX_EAP_OFFSET_MBE),
314 			(I82443BXGX_EAP_OFFSET_SBE |
315 				I82443BXGX_EAP_OFFSET_MBE));
316 
317 	mci->mod_name = EDAC_MOD_STR;
318 	mci->mod_ver = I82443_REVISION;
319 	mci->ctl_name = "I82443BXGX";
320 	mci->dev_name = pci_name(pdev);
321 	mci->edac_check = i82443bxgx_edacmc_check;
322 	mci->ctl_page_to_phys = NULL;
323 
324 	if (edac_mc_add_mc(mci)) {
325 		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
326 		goto fail;
327 	}
328 
329 	/* allocating generic PCI control info */
330 	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
331 	if (!i82443bxgx_pci) {
332 		printk(KERN_WARNING
333 			"%s(): Unable to create PCI control\n",
334 			__func__);
335 		printk(KERN_WARNING
336 			"%s(): PCI error report via EDAC not setup\n",
337 			__func__);
338 	}
339 
340 	debugf3("MC: " __FILE__ ": %s(): success\n", __func__);
341 	return 0;
342 
343 fail:
344 	edac_mc_free(mci);
345 	return -ENODEV;
346 }
347 
348 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);
349 
350 /* returns count (>= 0), or negative on error */
351 static int __devinit i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
352 						const struct pci_device_id *ent)
353 {
354 	int rc;
355 
356 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
357 
358 	/* don't need to call pci_device_enable() */
359 	rc = i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
360 
361 	if (mci_pdev == NULL)
362 		mci_pdev = pci_dev_get(pdev);
363 
364 	return rc;
365 }
366 
367 static void __devexit i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
368 {
369 	struct mem_ctl_info *mci;
370 
371 	debugf0(__FILE__ ": %s()\n", __func__);
372 
373 	if (i82443bxgx_pci)
374 		edac_pci_release_generic_ctl(i82443bxgx_pci);
375 
376 	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
377 		return;
378 
379 	edac_mc_free(mci);
380 }
381 
382 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);
383 
384 static const struct pci_device_id i82443bxgx_pci_tbl[] __devinitdata = {
385 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
386 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
387 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
388 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
389 	{0,}			/* 0 terminated list. */
390 };
391 
392 MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
393 
394 static struct pci_driver i82443bxgx_edacmc_driver = {
395 	.name = EDAC_MOD_STR,
396 	.probe = i82443bxgx_edacmc_init_one,
397 	.remove = __devexit_p(i82443bxgx_edacmc_remove_one),
398 	.id_table = i82443bxgx_pci_tbl,
399 };
400 
401 static int __init i82443bxgx_edacmc_init(void)
402 {
403 	int pci_rc;
404        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
405        opstate_init();
406 
407 	pci_rc = pci_register_driver(&i82443bxgx_edacmc_driver);
408 	if (pci_rc < 0)
409 		goto fail0;
410 
411 	if (mci_pdev == NULL) {
412 		const struct pci_device_id *id = &i82443bxgx_pci_tbl[0];
413 		int i = 0;
414 		i82443bxgx_registered = 0;
415 
416 		while (mci_pdev == NULL && id->vendor != 0) {
417 			mci_pdev = pci_get_device(id->vendor,
418 					id->device, NULL);
419 			i++;
420 			id = &i82443bxgx_pci_tbl[i];
421 		}
422 		if (!mci_pdev) {
423 			debugf0("i82443bxgx pci_get_device fail\n");
424 			pci_rc = -ENODEV;
425 			goto fail1;
426 		}
427 
428 		pci_rc = i82443bxgx_edacmc_init_one(mci_pdev, i82443bxgx_pci_tbl);
429 
430 		if (pci_rc < 0) {
431 			debugf0("i82443bxgx init fail\n");
432 			pci_rc = -ENODEV;
433 			goto fail1;
434 		}
435 	}
436 
437 	return 0;
438 
439 fail1:
440 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
441 
442 fail0:
443 	if (mci_pdev != NULL)
444 		pci_dev_put(mci_pdev);
445 
446 	return pci_rc;
447 }
448 
449 static void __exit i82443bxgx_edacmc_exit(void)
450 {
451 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
452 
453 	if (!i82443bxgx_registered)
454 		i82443bxgx_edacmc_remove_one(mci_pdev);
455 
456 	if (mci_pdev)
457 		pci_dev_put(mci_pdev);
458 }
459 
460 module_init(i82443bxgx_edacmc_init);
461 module_exit(i82443bxgx_edacmc_exit);
462 
463 MODULE_LICENSE("GPL");
464 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
465 MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
466 
467 module_param(edac_op_state, int, 0444);
468 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
469