xref: /linux/drivers/edac/i82443bxgx_edac.c (revision ab52c59103002b49f2455371e4b9c56ba3ef1781)
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://download.intel.com/design/chipsets/datashts/29063301.pdf
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 
31 #include <linux/edac.h>
32 #include "edac_module.h"
33 
34 #define EDAC_MOD_STR    "i82443bxgx_edac"
35 
36 /* The 82443BX supports SDRAM, or EDO (EDO for mobile only), "Memory
37  * Size: 8 MB to 512 MB (1GB with Registered DIMMs) with eight memory
38  * rows" "The 82443BX supports multiple-bit error detection and
39  * single-bit error correction when ECC mode is enabled and
40  * single/multi-bit error detection when correction is disabled.
41  * During writes to the DRAM, the 82443BX generates ECC for the data
42  * on a QWord basis. Partial QWord writes require a read-modify-write
43  * cycle when ECC is enabled."
44 */
45 
46 /* "Additionally, the 82443BX ensures that the data is corrected in
47  * main memory so that accumulation of errors is prevented. Another
48  * error within the same QWord would result in a double-bit error
49  * which is unrecoverable. This is known as hardware scrubbing since
50  * it requires no software intervention to correct the data in memory."
51  */
52 
53 /* [Also see page 100 (section 4.3), "DRAM Interface"]
54  * [Also see page 112 (section 4.6.1.4), ECC]
55  */
56 
57 #define I82443BXGX_NR_CSROWS 8
58 #define I82443BXGX_NR_CHANS  1
59 #define I82443BXGX_NR_DIMMS  4
60 
61 /* 82443 PCI Device 0 */
62 #define I82443BXGX_NBXCFG 0x50	/* 32bit register starting at this PCI
63 				 * config space offset */
64 #define I82443BXGX_NBXCFG_OFFSET_NON_ECCROW 24	/* Array of bits, zero if
65 						 * row is non-ECC */
66 #define I82443BXGX_NBXCFG_OFFSET_DRAM_FREQ 12	/* 2 bits,00=100MHz,10=66 MHz */
67 
68 #define I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY 7	/* 2 bits:       */
69 #define I82443BXGX_NBXCFG_INTEGRITY_NONE   0x0	/* 00 = Non-ECC */
70 #define I82443BXGX_NBXCFG_INTEGRITY_EC     0x1	/* 01 = EC (only) */
71 #define I82443BXGX_NBXCFG_INTEGRITY_ECC    0x2	/* 10 = ECC */
72 #define I82443BXGX_NBXCFG_INTEGRITY_SCRUB  0x3	/* 11 = ECC + HW Scrub */
73 
74 #define I82443BXGX_NBXCFG_OFFSET_ECC_DIAG_ENABLE  6
75 
76 /* 82443 PCI Device 0 */
77 #define I82443BXGX_EAP   0x80	/* 32bit register starting at this PCI
78 				 * config space offset, Error Address
79 				 * Pointer Register */
80 #define I82443BXGX_EAP_OFFSET_EAP  12	/* High 20 bits of error address */
81 #define I82443BXGX_EAP_OFFSET_MBE  BIT(1)	/* Err at EAP was multi-bit (W1TC) */
82 #define I82443BXGX_EAP_OFFSET_SBE  BIT(0)	/* Err at EAP was single-bit (W1TC) */
83 
84 #define I82443BXGX_ERRCMD  0x90	/* 8bit register starting at this PCI
85 				 * config space offset. */
86 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_MBE BIT(1)	/* 1 = enable */
87 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_SBE BIT(0)	/* 1 = enable */
88 
89 #define I82443BXGX_ERRSTS  0x91	/* 16bit register starting at this PCI
90 				 * config space offset. */
91 #define I82443BXGX_ERRSTS_OFFSET_MBFRE 5	/* 3 bits - first err row multibit */
92 #define I82443BXGX_ERRSTS_OFFSET_MEF   BIT(4)	/* 1 = MBE occurred */
93 #define I82443BXGX_ERRSTS_OFFSET_SBFRE 1	/* 3 bits - first err row singlebit */
94 #define I82443BXGX_ERRSTS_OFFSET_SEF   BIT(0)	/* 1 = SBE occurred */
95 
96 #define I82443BXGX_DRAMC 0x57	/* 8bit register starting at this PCI
97 				 * config space offset. */
98 #define I82443BXGX_DRAMC_OFFSET_DT 3	/* 2 bits, DRAM Type */
99 #define I82443BXGX_DRAMC_DRAM_IS_EDO 0	/* 00 = EDO */
100 #define I82443BXGX_DRAMC_DRAM_IS_SDRAM 1	/* 01 = SDRAM */
101 #define I82443BXGX_DRAMC_DRAM_IS_RSDRAM 2	/* 10 = Registered SDRAM */
102 
103 #define I82443BXGX_DRB 0x60	/* 8x 8bit registers starting at this PCI
104 				 * config space offset. */
105 
106 /* FIXME - don't poll when ECC disabled? */
107 
108 struct i82443bxgx_edacmc_error_info {
109 	u32 eap;
110 };
111 
112 static struct edac_pci_ctl_info *i82443bxgx_pci;
113 
114 static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
115 					 * already registered driver
116 					 */
117 
118 static int i82443bxgx_registered = 1;
119 
120 static void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
121 				struct i82443bxgx_edacmc_error_info
122 				*info)
123 {
124 	struct pci_dev *pdev;
125 	pdev = to_pci_dev(mci->pdev);
126 	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
127 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
128 		/* Clear error to allow next error to be reported [p.61] */
129 		pci_write_bits32(pdev, I82443BXGX_EAP,
130 				 I82443BXGX_EAP_OFFSET_SBE,
131 				 I82443BXGX_EAP_OFFSET_SBE);
132 
133 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
134 		/* Clear error to allow next error to be reported [p.61] */
135 		pci_write_bits32(pdev, I82443BXGX_EAP,
136 				 I82443BXGX_EAP_OFFSET_MBE,
137 				 I82443BXGX_EAP_OFFSET_MBE);
138 }
139 
140 static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
141 						struct
142 						i82443bxgx_edacmc_error_info
143 						*info, int handle_errors)
144 {
145 	int error_found = 0;
146 	u32 eapaddr, page, pageoffset;
147 
148 	/* bits 30:12 hold the 4kb block in which the error occurred
149 	 * [p.61] */
150 	eapaddr = (info->eap & 0xfffff000);
151 	page = eapaddr >> PAGE_SHIFT;
152 	pageoffset = eapaddr - (page << PAGE_SHIFT);
153 
154 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
155 		error_found = 1;
156 		if (handle_errors)
157 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
158 					     page, pageoffset, 0,
159 					     edac_mc_find_csrow_by_page(mci, page),
160 					     0, -1, mci->ctl_name, "");
161 	}
162 
163 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
164 		error_found = 1;
165 		if (handle_errors)
166 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
167 					     page, pageoffset, 0,
168 					     edac_mc_find_csrow_by_page(mci, page),
169 					     0, -1, mci->ctl_name, "");
170 	}
171 
172 	return error_found;
173 }
174 
175 static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
176 {
177 	struct i82443bxgx_edacmc_error_info info;
178 
179 	i82443bxgx_edacmc_get_error_info(mci, &info);
180 	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
181 }
182 
183 static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
184 				struct pci_dev *pdev,
185 				enum edac_type edac_mode,
186 				enum mem_type mtype)
187 {
188 	struct csrow_info *csrow;
189 	struct dimm_info *dimm;
190 	int index;
191 	u8 drbar, dramc;
192 	u32 row_base, row_high_limit, row_high_limit_last;
193 
194 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
195 	row_high_limit_last = 0;
196 	for (index = 0; index < mci->nr_csrows; index++) {
197 		csrow = mci->csrows[index];
198 		dimm = csrow->channels[0]->dimm;
199 
200 		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
201 		edac_dbg(1, "MC%d: Row=%d DRB = %#0x\n",
202 			 mci->mc_idx, index, drbar);
203 		row_high_limit = ((u32) drbar << 23);
204 		/* find the DRAM Chip Select Base address and mask */
205 		edac_dbg(1, "MC%d: Row=%d, Boundary Address=%#0x, Last = %#0x\n",
206 			 mci->mc_idx, index, row_high_limit,
207 			 row_high_limit_last);
208 
209 		/* 440GX goes to 2GB, represented with a DRB of 0. */
210 		if (row_high_limit_last && !row_high_limit)
211 			row_high_limit = 1UL << 31;
212 
213 		/* This row is empty [p.49] */
214 		if (row_high_limit == row_high_limit_last)
215 			continue;
216 		row_base = row_high_limit_last;
217 		csrow->first_page = row_base >> PAGE_SHIFT;
218 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
219 		dimm->nr_pages = csrow->last_page - csrow->first_page + 1;
220 		/* EAP reports in 4kilobyte granularity [61] */
221 		dimm->grain = 1 << 12;
222 		dimm->mtype = mtype;
223 		/* I don't think 440BX can tell you device type? FIXME? */
224 		dimm->dtype = DEV_UNKNOWN;
225 		/* Mode is global to all rows on 440BX */
226 		dimm->edac_mode = edac_mode;
227 		row_high_limit_last = row_high_limit;
228 	}
229 }
230 
231 static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
232 {
233 	struct mem_ctl_info *mci;
234 	struct edac_mc_layer layers[2];
235 	u8 dramc;
236 	u32 nbxcfg, ecc_mode;
237 	enum mem_type mtype;
238 	enum edac_type edac_mode;
239 
240 	edac_dbg(0, "MC:\n");
241 
242 	/* Something is really hosed if PCI config space reads from
243 	 * the MC aren't working.
244 	 */
245 	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
246 		return -EIO;
247 
248 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
249 	layers[0].size = I82443BXGX_NR_CSROWS;
250 	layers[0].is_virt_csrow = true;
251 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
252 	layers[1].size = I82443BXGX_NR_CHANS;
253 	layers[1].is_virt_csrow = false;
254 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
255 	if (mci == NULL)
256 		return -ENOMEM;
257 
258 	edac_dbg(0, "MC: mci = %p\n", mci);
259 	mci->pdev = &pdev->dev;
260 	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
261 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
262 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
263 	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
264 	case I82443BXGX_DRAMC_DRAM_IS_EDO:
265 		mtype = MEM_EDO;
266 		break;
267 	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
268 		mtype = MEM_SDR;
269 		break;
270 	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
271 		mtype = MEM_RDR;
272 		break;
273 	default:
274 		edac_dbg(0, "Unknown/reserved DRAM type value in DRAMC register!\n");
275 		mtype = -MEM_UNKNOWN;
276 	}
277 
278 	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
279 		mci->edac_cap = mci->edac_ctl_cap;
280 	else
281 		mci->edac_cap = EDAC_FLAG_NONE;
282 
283 	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
284 	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
285 	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
286 		(BIT(0) | BIT(1)));
287 
288 	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
289 		? SCRUB_HW_SRC : SCRUB_NONE;
290 
291 	switch (ecc_mode) {
292 	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
293 		edac_mode = EDAC_NONE;
294 		break;
295 	case I82443BXGX_NBXCFG_INTEGRITY_EC:
296 		edac_mode = EDAC_EC;
297 		break;
298 	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
299 	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
300 		edac_mode = EDAC_SECDED;
301 		break;
302 	default:
303 		edac_dbg(0, "Unknown/reserved ECC state in NBXCFG register!\n");
304 		edac_mode = EDAC_UNKNOWN;
305 		break;
306 	}
307 
308 	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
309 
310 	/* Many BIOSes don't clear error flags on boot, so do this
311 	 * here, or we get "phantom" errors occurring at module-load
312 	 * time. */
313 	pci_write_bits32(pdev, I82443BXGX_EAP,
314 			(I82443BXGX_EAP_OFFSET_SBE |
315 				I82443BXGX_EAP_OFFSET_MBE),
316 			(I82443BXGX_EAP_OFFSET_SBE |
317 				I82443BXGX_EAP_OFFSET_MBE));
318 
319 	mci->mod_name = EDAC_MOD_STR;
320 	mci->ctl_name = "I82443BXGX";
321 	mci->dev_name = pci_name(pdev);
322 	mci->edac_check = i82443bxgx_edacmc_check;
323 	mci->ctl_page_to_phys = NULL;
324 
325 	if (edac_mc_add_mc(mci)) {
326 		edac_dbg(3, "failed edac_mc_add_mc()\n");
327 		goto fail;
328 	}
329 
330 	/* allocating generic PCI control info */
331 	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
332 	if (!i82443bxgx_pci) {
333 		printk(KERN_WARNING
334 			"%s(): Unable to create PCI control\n",
335 			__func__);
336 		printk(KERN_WARNING
337 			"%s(): PCI error report via EDAC not setup\n",
338 			__func__);
339 	}
340 
341 	edac_dbg(3, "MC: success\n");
342 	return 0;
343 
344 fail:
345 	edac_mc_free(mci);
346 	return -ENODEV;
347 }
348 
349 /* returns count (>= 0), or negative on error */
350 static int i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
351 				      const struct pci_device_id *ent)
352 {
353 	int rc;
354 
355 	edac_dbg(0, "MC:\n");
356 
357 	/* don't need to call pci_enable_device() */
358 	rc = i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
359 
360 	if (mci_pdev == NULL)
361 		mci_pdev = pci_dev_get(pdev);
362 
363 	return rc;
364 }
365 
366 static void i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
367 {
368 	struct mem_ctl_info *mci;
369 
370 	edac_dbg(0, "\n");
371 
372 	if (i82443bxgx_pci)
373 		edac_pci_release_generic_ctl(i82443bxgx_pci);
374 
375 	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
376 		return;
377 
378 	edac_mc_free(mci);
379 }
380 
381 static const struct pci_device_id i82443bxgx_pci_tbl[] = {
382 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
383 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
384 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
385 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
386 	{0,}			/* 0 terminated list. */
387 };
388 
389 MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
390 
391 static struct pci_driver i82443bxgx_edacmc_driver = {
392 	.name = EDAC_MOD_STR,
393 	.probe = i82443bxgx_edacmc_init_one,
394 	.remove = i82443bxgx_edacmc_remove_one,
395 	.id_table = i82443bxgx_pci_tbl,
396 };
397 
398 static int __init i82443bxgx_edacmc_init(void)
399 {
400 	int pci_rc;
401        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
402        opstate_init();
403 
404 	pci_rc = pci_register_driver(&i82443bxgx_edacmc_driver);
405 	if (pci_rc < 0)
406 		goto fail0;
407 
408 	if (mci_pdev == NULL) {
409 		const struct pci_device_id *id = &i82443bxgx_pci_tbl[0];
410 		int i = 0;
411 		i82443bxgx_registered = 0;
412 
413 		while (mci_pdev == NULL && id->vendor != 0) {
414 			mci_pdev = pci_get_device(id->vendor,
415 					id->device, NULL);
416 			i++;
417 			id = &i82443bxgx_pci_tbl[i];
418 		}
419 		if (!mci_pdev) {
420 			edac_dbg(0, "i82443bxgx pci_get_device fail\n");
421 			pci_rc = -ENODEV;
422 			goto fail1;
423 		}
424 
425 		pci_rc = i82443bxgx_edacmc_init_one(mci_pdev, i82443bxgx_pci_tbl);
426 
427 		if (pci_rc < 0) {
428 			edac_dbg(0, "i82443bxgx init fail\n");
429 			pci_rc = -ENODEV;
430 			goto fail1;
431 		}
432 	}
433 
434 	return 0;
435 
436 fail1:
437 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
438 
439 fail0:
440 	pci_dev_put(mci_pdev);
441 	return pci_rc;
442 }
443 
444 static void __exit i82443bxgx_edacmc_exit(void)
445 {
446 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
447 
448 	if (!i82443bxgx_registered)
449 		i82443bxgx_edacmc_remove_one(mci_pdev);
450 
451 	pci_dev_put(mci_pdev);
452 }
453 
454 module_init(i82443bxgx_edacmc_init);
455 module_exit(i82443bxgx_edacmc_exit);
456 
457 MODULE_LICENSE("GPL");
458 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
459 MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
460 
461 module_param(edac_op_state, int, 0444);
462 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
463