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_core.h"
33 
34 #define I82443_REVISION	"0.1"
35 
36 #define EDAC_MOD_STR    "i82443bxgx_edac"
37 
38 /* The 82443BX supports SDRAM, or EDO (EDO for mobile only), "Memory
39  * Size: 8 MB to 512 MB (1GB with Registered DIMMs) with eight memory
40  * rows" "The 82443BX supports multiple-bit error detection and
41  * single-bit error correction when ECC mode is enabled and
42  * single/multi-bit error detection when correction is disabled.
43  * During writes to the DRAM, the 82443BX generates ECC for the data
44  * on a QWord basis. Partial QWord writes require a read-modify-write
45  * cycle when ECC is enabled."
46 */
47 
48 /* "Additionally, the 82443BX ensures that the data is corrected in
49  * main memory so that accumulation of errors is prevented. Another
50  * error within the same QWord would result in a double-bit error
51  * which is unrecoverable. This is known as hardware scrubbing since
52  * it requires no software intervention to correct the data in memory."
53  */
54 
55 /* [Also see page 100 (section 4.3), "DRAM Interface"]
56  * [Also see page 112 (section 4.6.1.4), ECC]
57  */
58 
59 #define I82443BXGX_NR_CSROWS 8
60 #define I82443BXGX_NR_CHANS  1
61 #define I82443BXGX_NR_DIMMS  4
62 
63 /* 82443 PCI Device 0 */
64 #define I82443BXGX_NBXCFG 0x50	/* 32bit register starting at this PCI
65 				 * config space offset */
66 #define I82443BXGX_NBXCFG_OFFSET_NON_ECCROW 24	/* Array of bits, zero if
67 						 * row is non-ECC */
68 #define I82443BXGX_NBXCFG_OFFSET_DRAM_FREQ 12	/* 2 bits,00=100MHz,10=66 MHz */
69 
70 #define I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY 7	/* 2 bits:       */
71 #define I82443BXGX_NBXCFG_INTEGRITY_NONE   0x0	/* 00 = Non-ECC */
72 #define I82443BXGX_NBXCFG_INTEGRITY_EC     0x1	/* 01 = EC (only) */
73 #define I82443BXGX_NBXCFG_INTEGRITY_ECC    0x2	/* 10 = ECC */
74 #define I82443BXGX_NBXCFG_INTEGRITY_SCRUB  0x3	/* 11 = ECC + HW Scrub */
75 
76 #define I82443BXGX_NBXCFG_OFFSET_ECC_DIAG_ENABLE  6
77 
78 /* 82443 PCI Device 0 */
79 #define I82443BXGX_EAP   0x80	/* 32bit register starting at this PCI
80 				 * config space offset, Error Address
81 				 * Pointer Register */
82 #define I82443BXGX_EAP_OFFSET_EAP  12	/* High 20 bits of error address */
83 #define I82443BXGX_EAP_OFFSET_MBE  BIT(1)	/* Err at EAP was multi-bit (W1TC) */
84 #define I82443BXGX_EAP_OFFSET_SBE  BIT(0)	/* Err at EAP was single-bit (W1TC) */
85 
86 #define I82443BXGX_ERRCMD  0x90	/* 8bit register starting at this PCI
87 				 * config space offset. */
88 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_MBE BIT(1)	/* 1 = enable */
89 #define I82443BXGX_ERRCMD_OFFSET_SERR_ON_SBE BIT(0)	/* 1 = enable */
90 
91 #define I82443BXGX_ERRSTS  0x91	/* 16bit register starting at this PCI
92 				 * config space offset. */
93 #define I82443BXGX_ERRSTS_OFFSET_MBFRE 5	/* 3 bits - first err row multibit */
94 #define I82443BXGX_ERRSTS_OFFSET_MEF   BIT(4)	/* 1 = MBE occurred */
95 #define I82443BXGX_ERRSTS_OFFSET_SBFRE 1	/* 3 bits - first err row singlebit */
96 #define I82443BXGX_ERRSTS_OFFSET_SEF   BIT(0)	/* 1 = SBE occurred */
97 
98 #define I82443BXGX_DRAMC 0x57	/* 8bit register starting at this PCI
99 				 * config space offset. */
100 #define I82443BXGX_DRAMC_OFFSET_DT 3	/* 2 bits, DRAM Type */
101 #define I82443BXGX_DRAMC_DRAM_IS_EDO 0	/* 00 = EDO */
102 #define I82443BXGX_DRAMC_DRAM_IS_SDRAM 1	/* 01 = SDRAM */
103 #define I82443BXGX_DRAMC_DRAM_IS_RSDRAM 2	/* 10 = Registered SDRAM */
104 
105 #define I82443BXGX_DRB 0x60	/* 8x 8bit registers starting at this PCI
106 				 * config space offset. */
107 
108 /* FIXME - don't poll when ECC disabled? */
109 
110 struct i82443bxgx_edacmc_error_info {
111 	u32 eap;
112 };
113 
114 static struct edac_pci_ctl_info *i82443bxgx_pci;
115 
116 static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
117 					 * already registered driver
118 					 */
119 
120 static int i82443bxgx_registered = 1;
121 
122 static void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
123 				struct i82443bxgx_edacmc_error_info
124 				*info)
125 {
126 	struct pci_dev *pdev;
127 	pdev = to_pci_dev(mci->pdev);
128 	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
129 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
130 		/* Clear error to allow next error to be reported [p.61] */
131 		pci_write_bits32(pdev, I82443BXGX_EAP,
132 				 I82443BXGX_EAP_OFFSET_SBE,
133 				 I82443BXGX_EAP_OFFSET_SBE);
134 
135 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
136 		/* Clear error to allow next error to be reported [p.61] */
137 		pci_write_bits32(pdev, I82443BXGX_EAP,
138 				 I82443BXGX_EAP_OFFSET_MBE,
139 				 I82443BXGX_EAP_OFFSET_MBE);
140 }
141 
142 static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
143 						struct
144 						i82443bxgx_edacmc_error_info
145 						*info, int handle_errors)
146 {
147 	int error_found = 0;
148 	u32 eapaddr, page, pageoffset;
149 
150 	/* bits 30:12 hold the 4kb block in which the error occurred
151 	 * [p.61] */
152 	eapaddr = (info->eap & 0xfffff000);
153 	page = eapaddr >> PAGE_SHIFT;
154 	pageoffset = eapaddr - (page << PAGE_SHIFT);
155 
156 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
157 		error_found = 1;
158 		if (handle_errors)
159 			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
160 					     page, pageoffset, 0,
161 					     edac_mc_find_csrow_by_page(mci, page),
162 					     0, -1, mci->ctl_name, "");
163 	}
164 
165 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
166 		error_found = 1;
167 		if (handle_errors)
168 			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
169 					     page, pageoffset, 0,
170 					     edac_mc_find_csrow_by_page(mci, page),
171 					     0, -1, mci->ctl_name, "");
172 	}
173 
174 	return error_found;
175 }
176 
177 static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
178 {
179 	struct i82443bxgx_edacmc_error_info info;
180 
181 	edac_dbg(1, "MC%d\n", mci->mc_idx);
182 	i82443bxgx_edacmc_get_error_info(mci, &info);
183 	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
184 }
185 
186 static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
187 				struct pci_dev *pdev,
188 				enum edac_type edac_mode,
189 				enum mem_type mtype)
190 {
191 	struct csrow_info *csrow;
192 	struct dimm_info *dimm;
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 		dimm = csrow->channels[0]->dimm;
202 
203 		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
204 		edac_dbg(1, "MC%d: Row=%d DRB = %#0x\n",
205 			 mci->mc_idx, index, drbar);
206 		row_high_limit = ((u32) drbar << 23);
207 		/* find the DRAM Chip Select Base address and mask */
208 		edac_dbg(1, "MC%d: Row=%d, Boundary Address=%#0x, Last = %#0x\n",
209 			 mci->mc_idx, index, row_high_limit,
210 			 row_high_limit_last);
211 
212 		/* 440GX goes to 2GB, represented with a DRB of 0. */
213 		if (row_high_limit_last && !row_high_limit)
214 			row_high_limit = 1UL << 31;
215 
216 		/* This row is empty [p.49] */
217 		if (row_high_limit == row_high_limit_last)
218 			continue;
219 		row_base = row_high_limit_last;
220 		csrow->first_page = row_base >> PAGE_SHIFT;
221 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
222 		dimm->nr_pages = csrow->last_page - csrow->first_page + 1;
223 		/* EAP reports in 4kilobyte granularity [61] */
224 		dimm->grain = 1 << 12;
225 		dimm->mtype = mtype;
226 		/* I don't think 440BX can tell you device type? FIXME? */
227 		dimm->dtype = DEV_UNKNOWN;
228 		/* Mode is global to all rows on 440BX */
229 		dimm->edac_mode = edac_mode;
230 		row_high_limit_last = row_high_limit;
231 	}
232 }
233 
234 static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
235 {
236 	struct mem_ctl_info *mci;
237 	struct edac_mc_layer layers[2];
238 	u8 dramc;
239 	u32 nbxcfg, ecc_mode;
240 	enum mem_type mtype;
241 	enum edac_type edac_mode;
242 
243 	edac_dbg(0, "MC:\n");
244 
245 	/* Something is really hosed if PCI config space reads from
246 	 * the MC aren't working.
247 	 */
248 	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
249 		return -EIO;
250 
251 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
252 	layers[0].size = I82443BXGX_NR_CSROWS;
253 	layers[0].is_virt_csrow = true;
254 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
255 	layers[1].size = I82443BXGX_NR_CHANS;
256 	layers[1].is_virt_csrow = false;
257 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
258 	if (mci == NULL)
259 		return -ENOMEM;
260 
261 	edac_dbg(0, "MC: mci = %p\n", mci);
262 	mci->pdev = &pdev->dev;
263 	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
264 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
265 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
266 	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
267 	case I82443BXGX_DRAMC_DRAM_IS_EDO:
268 		mtype = MEM_EDO;
269 		break;
270 	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
271 		mtype = MEM_SDR;
272 		break;
273 	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
274 		mtype = MEM_RDR;
275 		break;
276 	default:
277 		edac_dbg(0, "Unknown/reserved DRAM type value in DRAMC register!\n");
278 		mtype = -MEM_UNKNOWN;
279 	}
280 
281 	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
282 		mci->edac_cap = mci->edac_ctl_cap;
283 	else
284 		mci->edac_cap = EDAC_FLAG_NONE;
285 
286 	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
287 	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
288 	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
289 		(BIT(0) | BIT(1)));
290 
291 	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
292 		? SCRUB_HW_SRC : SCRUB_NONE;
293 
294 	switch (ecc_mode) {
295 	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
296 		edac_mode = EDAC_NONE;
297 		break;
298 	case I82443BXGX_NBXCFG_INTEGRITY_EC:
299 		edac_mode = EDAC_EC;
300 		break;
301 	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
302 	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
303 		edac_mode = EDAC_SECDED;
304 		break;
305 	default:
306 		edac_dbg(0, "Unknown/reserved ECC state in NBXCFG register!\n");
307 		edac_mode = EDAC_UNKNOWN;
308 		break;
309 	}
310 
311 	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
312 
313 	/* Many BIOSes don't clear error flags on boot, so do this
314 	 * here, or we get "phantom" errors occurring at module-load
315 	 * time. */
316 	pci_write_bits32(pdev, I82443BXGX_EAP,
317 			(I82443BXGX_EAP_OFFSET_SBE |
318 				I82443BXGX_EAP_OFFSET_MBE),
319 			(I82443BXGX_EAP_OFFSET_SBE |
320 				I82443BXGX_EAP_OFFSET_MBE));
321 
322 	mci->mod_name = EDAC_MOD_STR;
323 	mci->mod_ver = I82443_REVISION;
324 	mci->ctl_name = "I82443BXGX";
325 	mci->dev_name = pci_name(pdev);
326 	mci->edac_check = i82443bxgx_edacmc_check;
327 	mci->ctl_page_to_phys = NULL;
328 
329 	if (edac_mc_add_mc(mci)) {
330 		edac_dbg(3, "failed edac_mc_add_mc()\n");
331 		goto fail;
332 	}
333 
334 	/* allocating generic PCI control info */
335 	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
336 	if (!i82443bxgx_pci) {
337 		printk(KERN_WARNING
338 			"%s(): Unable to create PCI control\n",
339 			__func__);
340 		printk(KERN_WARNING
341 			"%s(): PCI error report via EDAC not setup\n",
342 			__func__);
343 	}
344 
345 	edac_dbg(3, "MC: success\n");
346 	return 0;
347 
348 fail:
349 	edac_mc_free(mci);
350 	return -ENODEV;
351 }
352 
353 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);
354 
355 /* returns count (>= 0), or negative on error */
356 static int i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
357 				      const struct pci_device_id *ent)
358 {
359 	int rc;
360 
361 	edac_dbg(0, "MC:\n");
362 
363 	/* don't need to call pci_enable_device() */
364 	rc = i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
365 
366 	if (mci_pdev == NULL)
367 		mci_pdev = pci_dev_get(pdev);
368 
369 	return rc;
370 }
371 
372 static void i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
373 {
374 	struct mem_ctl_info *mci;
375 
376 	edac_dbg(0, "\n");
377 
378 	if (i82443bxgx_pci)
379 		edac_pci_release_generic_ctl(i82443bxgx_pci);
380 
381 	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
382 		return;
383 
384 	edac_mc_free(mci);
385 }
386 
387 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);
388 
389 static DEFINE_PCI_DEVICE_TABLE(i82443bxgx_pci_tbl) = {
390 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
391 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
392 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
393 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
394 	{0,}			/* 0 terminated list. */
395 };
396 
397 MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
398 
399 static struct pci_driver i82443bxgx_edacmc_driver = {
400 	.name = EDAC_MOD_STR,
401 	.probe = i82443bxgx_edacmc_init_one,
402 	.remove = i82443bxgx_edacmc_remove_one,
403 	.id_table = i82443bxgx_pci_tbl,
404 };
405 
406 static int __init i82443bxgx_edacmc_init(void)
407 {
408 	int pci_rc;
409        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
410        opstate_init();
411 
412 	pci_rc = pci_register_driver(&i82443bxgx_edacmc_driver);
413 	if (pci_rc < 0)
414 		goto fail0;
415 
416 	if (mci_pdev == NULL) {
417 		const struct pci_device_id *id = &i82443bxgx_pci_tbl[0];
418 		int i = 0;
419 		i82443bxgx_registered = 0;
420 
421 		while (mci_pdev == NULL && id->vendor != 0) {
422 			mci_pdev = pci_get_device(id->vendor,
423 					id->device, NULL);
424 			i++;
425 			id = &i82443bxgx_pci_tbl[i];
426 		}
427 		if (!mci_pdev) {
428 			edac_dbg(0, "i82443bxgx pci_get_device fail\n");
429 			pci_rc = -ENODEV;
430 			goto fail1;
431 		}
432 
433 		pci_rc = i82443bxgx_edacmc_init_one(mci_pdev, i82443bxgx_pci_tbl);
434 
435 		if (pci_rc < 0) {
436 			edac_dbg(0, "i82443bxgx init fail\n");
437 			pci_rc = -ENODEV;
438 			goto fail1;
439 		}
440 	}
441 
442 	return 0;
443 
444 fail1:
445 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
446 
447 fail0:
448 	if (mci_pdev != NULL)
449 		pci_dev_put(mci_pdev);
450 
451 	return pci_rc;
452 }
453 
454 static void __exit i82443bxgx_edacmc_exit(void)
455 {
456 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
457 
458 	if (!i82443bxgx_registered)
459 		i82443bxgx_edacmc_remove_one(mci_pdev);
460 
461 	if (mci_pdev)
462 		pci_dev_put(mci_pdev);
463 }
464 
465 module_init(i82443bxgx_edacmc_init);
466 module_exit(i82443bxgx_edacmc_exit);
467 
468 MODULE_LICENSE("GPL");
469 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
470 MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
471 
472 module_param(edac_op_state, int, 0444);
473 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
474