xref: /linux/drivers/edac/i82443bxgx_edac.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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 "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 void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
117 				struct i82443bxgx_edacmc_error_info
118 				*info)
119 {
120 	struct pci_dev *pdev;
121 	pdev = to_pci_dev(mci->dev);
122 	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
123 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
124 		/* Clear error to allow next error to be reported [p.61] */
125 		pci_write_bits32(pdev, I82443BXGX_EAP,
126 				 I82443BXGX_EAP_OFFSET_SBE,
127 				 I82443BXGX_EAP_OFFSET_SBE);
128 
129 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
130 		/* Clear error to allow next error to be reported [p.61] */
131 		pci_write_bits32(pdev, I82443BXGX_EAP,
132 				 I82443BXGX_EAP_OFFSET_MBE,
133 				 I82443BXGX_EAP_OFFSET_MBE);
134 }
135 
136 static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
137 						struct
138 						i82443bxgx_edacmc_error_info
139 						*info, int handle_errors)
140 {
141 	int error_found = 0;
142 	u32 eapaddr, page, pageoffset;
143 
144 	/* bits 30:12 hold the 4kb block in which the error occurred
145 	 * [p.61] */
146 	eapaddr = (info->eap & 0xfffff000);
147 	page = eapaddr >> PAGE_SHIFT;
148 	pageoffset = eapaddr - (page << PAGE_SHIFT);
149 
150 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
151 		error_found = 1;
152 		if (handle_errors)
153 			edac_mc_handle_ce(mci, page, pageoffset,
154 				/* 440BX/GX don't make syndrome information
155 				 * available */
156 				0, edac_mc_find_csrow_by_page(mci, page), 0,
157 				mci->ctl_name);
158 	}
159 
160 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
161 		error_found = 1;
162 		if (handle_errors)
163 			edac_mc_handle_ue(mci, page, pageoffset,
164 					edac_mc_find_csrow_by_page(mci, page),
165 					mci->ctl_name);
166 	}
167 
168 	return error_found;
169 }
170 
171 static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
172 {
173 	struct i82443bxgx_edacmc_error_info info;
174 
175 	debugf1("MC%d: " __FILE__ ": %s()\n", mci->mc_idx, __func__);
176 	i82443bxgx_edacmc_get_error_info(mci, &info);
177 	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
178 }
179 
180 static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
181 				struct pci_dev *pdev,
182 				enum edac_type edac_mode,
183 				enum mem_type mtype)
184 {
185 	struct csrow_info *csrow;
186 	int index;
187 	u8 drbar, dramc;
188 	u32 row_base, row_high_limit, row_high_limit_last;
189 
190 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
191 	row_high_limit_last = 0;
192 	for (index = 0; index < mci->nr_csrows; index++) {
193 		csrow = &mci->csrows[index];
194 		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
195 		debugf1("MC%d: " __FILE__ ": %s() Row=%d DRB = %#0x\n",
196 			mci->mc_idx, __func__, index, drbar);
197 		row_high_limit = ((u32) drbar << 23);
198 		/* find the DRAM Chip Select Base address and mask */
199 		debugf1("MC%d: " __FILE__ ": %s() Row=%d, "
200 			"Boundry Address=%#0x, Last = %#0x \n",
201 			mci->mc_idx, __func__, index, row_high_limit,
202 			row_high_limit_last);
203 
204 		/* 440GX goes to 2GB, represented with a DRB of 0. */
205 		if (row_high_limit_last && !row_high_limit)
206 			row_high_limit = 1UL << 31;
207 
208 		/* This row is empty [p.49] */
209 		if (row_high_limit == row_high_limit_last)
210 			continue;
211 		row_base = row_high_limit_last;
212 		csrow->first_page = row_base >> PAGE_SHIFT;
213 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
214 		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
215 		/* EAP reports in 4kilobyte granularity [61] */
216 		csrow->grain = 1 << 12;
217 		csrow->mtype = mtype;
218 		/* I don't think 440BX can tell you device type? FIXME? */
219 		csrow->dtype = DEV_UNKNOWN;
220 		/* Mode is global to all rows on 440BX */
221 		csrow->edac_mode = edac_mode;
222 		row_high_limit_last = row_high_limit;
223 	}
224 }
225 
226 static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
227 {
228 	struct mem_ctl_info *mci;
229 	u8 dramc;
230 	u32 nbxcfg, ecc_mode;
231 	enum mem_type mtype;
232 	enum edac_type edac_mode;
233 
234 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
235 
236 	/* Something is really hosed if PCI config space reads from
237 	 * the MC aren't working.
238 	 */
239 	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
240 		return -EIO;
241 
242 	mci = edac_mc_alloc(0, I82443BXGX_NR_CSROWS, I82443BXGX_NR_CHANS, 0);
243 
244 	if (mci == NULL)
245 		return -ENOMEM;
246 
247 	debugf0("MC: " __FILE__ ": %s(): mci = %p\n", __func__, mci);
248 	mci->dev = &pdev->dev;
249 	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
250 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
251 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
252 	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
253 	case I82443BXGX_DRAMC_DRAM_IS_EDO:
254 		mtype = MEM_EDO;
255 		break;
256 	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
257 		mtype = MEM_SDR;
258 		break;
259 	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
260 		mtype = MEM_RDR;
261 		break;
262 	default:
263 		debugf0("Unknown/reserved DRAM type value "
264 			"in DRAMC register!\n");
265 		mtype = -MEM_UNKNOWN;
266 	}
267 
268 	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
269 		mci->edac_cap = mci->edac_ctl_cap;
270 	else
271 		mci->edac_cap = EDAC_FLAG_NONE;
272 
273 	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
274 	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
275 	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
276 		(BIT(0) | BIT(1)));
277 
278 	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
279 		? SCRUB_HW_SRC : SCRUB_NONE;
280 
281 	switch (ecc_mode) {
282 	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
283 		edac_mode = EDAC_NONE;
284 		break;
285 	case I82443BXGX_NBXCFG_INTEGRITY_EC:
286 		edac_mode = EDAC_EC;
287 		break;
288 	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
289 	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
290 		edac_mode = EDAC_SECDED;
291 		break;
292 	default:
293 		debugf0("%s(): Unknown/reserved ECC state "
294 			"in NBXCFG register!\n", __func__);
295 		edac_mode = EDAC_UNKNOWN;
296 		break;
297 	}
298 
299 	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
300 
301 	/* Many BIOSes don't clear error flags on boot, so do this
302 	 * here, or we get "phantom" errors occuring at module-load
303 	 * time. */
304 	pci_write_bits32(pdev, I82443BXGX_EAP,
305 			(I82443BXGX_EAP_OFFSET_SBE |
306 				I82443BXGX_EAP_OFFSET_MBE),
307 			(I82443BXGX_EAP_OFFSET_SBE |
308 				I82443BXGX_EAP_OFFSET_MBE));
309 
310 	mci->mod_name = EDAC_MOD_STR;
311 	mci->mod_ver = I82443_REVISION;
312 	mci->ctl_name = "I82443BXGX";
313 	mci->dev_name = pci_name(pdev);
314 	mci->edac_check = i82443bxgx_edacmc_check;
315 	mci->ctl_page_to_phys = NULL;
316 
317 	if (edac_mc_add_mc(mci)) {
318 		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
319 		goto fail;
320 	}
321 
322 	/* allocating generic PCI control info */
323 	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
324 	if (!i82443bxgx_pci) {
325 		printk(KERN_WARNING
326 			"%s(): Unable to create PCI control\n",
327 			__func__);
328 		printk(KERN_WARNING
329 			"%s(): PCI error report via EDAC not setup\n",
330 			__func__);
331 	}
332 
333 	debugf3("MC: " __FILE__ ": %s(): success\n", __func__);
334 	return 0;
335 
336 fail:
337 	edac_mc_free(mci);
338 	return -ENODEV;
339 }
340 
341 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);
342 
343 /* returns count (>= 0), or negative on error */
344 static int __devinit i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
345 						const struct pci_device_id *ent)
346 {
347 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
348 
349 	/* don't need to call pci_device_enable() */
350 	return i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
351 }
352 
353 static void __devexit i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
354 {
355 	struct mem_ctl_info *mci;
356 
357 	debugf0(__FILE__ ": %s()\n", __func__);
358 
359 	if (i82443bxgx_pci)
360 		edac_pci_release_generic_ctl(i82443bxgx_pci);
361 
362 	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
363 		return;
364 
365 	edac_mc_free(mci);
366 }
367 
368 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);
369 
370 static const struct pci_device_id i82443bxgx_pci_tbl[] __devinitdata = {
371 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
372 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
373 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
374 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
375 	{0,}			/* 0 terminated list. */
376 };
377 
378 MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
379 
380 static struct pci_driver i82443bxgx_edacmc_driver = {
381 	.name = EDAC_MOD_STR,
382 	.probe = i82443bxgx_edacmc_init_one,
383 	.remove = __devexit_p(i82443bxgx_edacmc_remove_one),
384 	.id_table = i82443bxgx_pci_tbl,
385 };
386 
387 static int __init i82443bxgx_edacmc_init(void)
388 {
389 	return pci_register_driver(&i82443bxgx_edacmc_driver);
390 }
391 
392 static void __exit i82443bxgx_edacmc_exit(void)
393 {
394 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
395 }
396 
397 module_init(i82443bxgx_edacmc_init);
398 module_exit(i82443bxgx_edacmc_exit);
399 
400 MODULE_LICENSE("GPL");
401 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
402 MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
403