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 void i82443bxgx_edacmc_get_error_info(struct mem_ctl_info *mci,
118 				struct i82443bxgx_edacmc_error_info
119 				*info)
120 {
121 	struct pci_dev *pdev;
122 	pdev = to_pci_dev(mci->dev);
123 	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
124 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
125 		/* Clear error to allow next error to be reported [p.61] */
126 		pci_write_bits32(pdev, I82443BXGX_EAP,
127 				 I82443BXGX_EAP_OFFSET_SBE,
128 				 I82443BXGX_EAP_OFFSET_SBE);
129 
130 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
131 		/* Clear error to allow next error to be reported [p.61] */
132 		pci_write_bits32(pdev, I82443BXGX_EAP,
133 				 I82443BXGX_EAP_OFFSET_MBE,
134 				 I82443BXGX_EAP_OFFSET_MBE);
135 }
136 
137 static int i82443bxgx_edacmc_process_error_info(struct mem_ctl_info *mci,
138 						struct
139 						i82443bxgx_edacmc_error_info
140 						*info, int handle_errors)
141 {
142 	int error_found = 0;
143 	u32 eapaddr, page, pageoffset;
144 
145 	/* bits 30:12 hold the 4kb block in which the error occurred
146 	 * [p.61] */
147 	eapaddr = (info->eap & 0xfffff000);
148 	page = eapaddr >> PAGE_SHIFT;
149 	pageoffset = eapaddr - (page << PAGE_SHIFT);
150 
151 	if (info->eap & I82443BXGX_EAP_OFFSET_SBE) {
152 		error_found = 1;
153 		if (handle_errors)
154 			edac_mc_handle_ce(mci, page, pageoffset,
155 				/* 440BX/GX don't make syndrome information
156 				 * available */
157 				0, edac_mc_find_csrow_by_page(mci, page), 0,
158 				mci->ctl_name);
159 	}
160 
161 	if (info->eap & I82443BXGX_EAP_OFFSET_MBE) {
162 		error_found = 1;
163 		if (handle_errors)
164 			edac_mc_handle_ue(mci, page, pageoffset,
165 					edac_mc_find_csrow_by_page(mci, page),
166 					mci->ctl_name);
167 	}
168 
169 	return error_found;
170 }
171 
172 static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
173 {
174 	struct i82443bxgx_edacmc_error_info info;
175 
176 	debugf1("MC%d: " __FILE__ ": %s()\n", mci->mc_idx, __func__);
177 	i82443bxgx_edacmc_get_error_info(mci, &info);
178 	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
179 }
180 
181 static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
182 				struct pci_dev *pdev,
183 				enum edac_type edac_mode,
184 				enum mem_type mtype)
185 {
186 	struct csrow_info *csrow;
187 	int index;
188 	u8 drbar, dramc;
189 	u32 row_base, row_high_limit, row_high_limit_last;
190 
191 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
192 	row_high_limit_last = 0;
193 	for (index = 0; index < mci->nr_csrows; index++) {
194 		csrow = &mci->csrows[index];
195 		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
196 		debugf1("MC%d: " __FILE__ ": %s() Row=%d DRB = %#0x\n",
197 			mci->mc_idx, __func__, index, drbar);
198 		row_high_limit = ((u32) drbar << 23);
199 		/* find the DRAM Chip Select Base address and mask */
200 		debugf1("MC%d: " __FILE__ ": %s() Row=%d, "
201 			"Boundry Address=%#0x, Last = %#0x \n",
202 			mci->mc_idx, __func__, index, row_high_limit,
203 			row_high_limit_last);
204 
205 		/* 440GX goes to 2GB, represented with a DRB of 0. */
206 		if (row_high_limit_last && !row_high_limit)
207 			row_high_limit = 1UL << 31;
208 
209 		/* This row is empty [p.49] */
210 		if (row_high_limit == row_high_limit_last)
211 			continue;
212 		row_base = row_high_limit_last;
213 		csrow->first_page = row_base >> PAGE_SHIFT;
214 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
215 		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
216 		/* EAP reports in 4kilobyte granularity [61] */
217 		csrow->grain = 1 << 12;
218 		csrow->mtype = mtype;
219 		/* I don't think 440BX can tell you device type? FIXME? */
220 		csrow->dtype = DEV_UNKNOWN;
221 		/* Mode is global to all rows on 440BX */
222 		csrow->edac_mode = edac_mode;
223 		row_high_limit_last = row_high_limit;
224 	}
225 }
226 
227 static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
228 {
229 	struct mem_ctl_info *mci;
230 	u8 dramc;
231 	u32 nbxcfg, ecc_mode;
232 	enum mem_type mtype;
233 	enum edac_type edac_mode;
234 
235 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
236 
237 	/* Something is really hosed if PCI config space reads from
238 	 * the MC aren't working.
239 	 */
240 	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
241 		return -EIO;
242 
243 	mci = edac_mc_alloc(0, I82443BXGX_NR_CSROWS, I82443BXGX_NR_CHANS, 0);
244 
245 	if (mci == NULL)
246 		return -ENOMEM;
247 
248 	debugf0("MC: " __FILE__ ": %s(): mci = %p\n", __func__, mci);
249 	mci->dev = &pdev->dev;
250 	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
251 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
252 	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
253 	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
254 	case I82443BXGX_DRAMC_DRAM_IS_EDO:
255 		mtype = MEM_EDO;
256 		break;
257 	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
258 		mtype = MEM_SDR;
259 		break;
260 	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
261 		mtype = MEM_RDR;
262 		break;
263 	default:
264 		debugf0("Unknown/reserved DRAM type value "
265 			"in DRAMC register!\n");
266 		mtype = -MEM_UNKNOWN;
267 	}
268 
269 	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
270 		mci->edac_cap = mci->edac_ctl_cap;
271 	else
272 		mci->edac_cap = EDAC_FLAG_NONE;
273 
274 	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
275 	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
276 	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
277 		(BIT(0) | BIT(1)));
278 
279 	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
280 		? SCRUB_HW_SRC : SCRUB_NONE;
281 
282 	switch (ecc_mode) {
283 	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
284 		edac_mode = EDAC_NONE;
285 		break;
286 	case I82443BXGX_NBXCFG_INTEGRITY_EC:
287 		edac_mode = EDAC_EC;
288 		break;
289 	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
290 	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
291 		edac_mode = EDAC_SECDED;
292 		break;
293 	default:
294 		debugf0("%s(): Unknown/reserved ECC state "
295 			"in NBXCFG register!\n", __func__);
296 		edac_mode = EDAC_UNKNOWN;
297 		break;
298 	}
299 
300 	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
301 
302 	/* Many BIOSes don't clear error flags on boot, so do this
303 	 * here, or we get "phantom" errors occuring at module-load
304 	 * time. */
305 	pci_write_bits32(pdev, I82443BXGX_EAP,
306 			(I82443BXGX_EAP_OFFSET_SBE |
307 				I82443BXGX_EAP_OFFSET_MBE),
308 			(I82443BXGX_EAP_OFFSET_SBE |
309 				I82443BXGX_EAP_OFFSET_MBE));
310 
311 	mci->mod_name = EDAC_MOD_STR;
312 	mci->mod_ver = I82443_REVISION;
313 	mci->ctl_name = "I82443BXGX";
314 	mci->dev_name = pci_name(pdev);
315 	mci->edac_check = i82443bxgx_edacmc_check;
316 	mci->ctl_page_to_phys = NULL;
317 
318 	if (edac_mc_add_mc(mci)) {
319 		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
320 		goto fail;
321 	}
322 
323 	/* allocating generic PCI control info */
324 	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
325 	if (!i82443bxgx_pci) {
326 		printk(KERN_WARNING
327 			"%s(): Unable to create PCI control\n",
328 			__func__);
329 		printk(KERN_WARNING
330 			"%s(): PCI error report via EDAC not setup\n",
331 			__func__);
332 	}
333 
334 	debugf3("MC: " __FILE__ ": %s(): success\n", __func__);
335 	return 0;
336 
337 fail:
338 	edac_mc_free(mci);
339 	return -ENODEV;
340 }
341 
342 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);
343 
344 /* returns count (>= 0), or negative on error */
345 static int __devinit i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
346 						const struct pci_device_id *ent)
347 {
348 	debugf0("MC: " __FILE__ ": %s()\n", __func__);
349 
350 	/* don't need to call pci_device_enable() */
351 	return i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
352 }
353 
354 static void __devexit i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
355 {
356 	struct mem_ctl_info *mci;
357 
358 	debugf0(__FILE__ ": %s()\n", __func__);
359 
360 	if (i82443bxgx_pci)
361 		edac_pci_release_generic_ctl(i82443bxgx_pci);
362 
363 	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
364 		return;
365 
366 	edac_mc_free(mci);
367 }
368 
369 EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);
370 
371 static const struct pci_device_id i82443bxgx_pci_tbl[] __devinitdata = {
372 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
373 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
374 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
375 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
376 	{0,}			/* 0 terminated list. */
377 };
378 
379 MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
380 
381 static struct pci_driver i82443bxgx_edacmc_driver = {
382 	.name = EDAC_MOD_STR,
383 	.probe = i82443bxgx_edacmc_init_one,
384 	.remove = __devexit_p(i82443bxgx_edacmc_remove_one),
385 	.id_table = i82443bxgx_pci_tbl,
386 };
387 
388 static int __init i82443bxgx_edacmc_init(void)
389 {
390        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
391        opstate_init();
392 
393 	return pci_register_driver(&i82443bxgx_edacmc_driver);
394 }
395 
396 static void __exit i82443bxgx_edacmc_exit(void)
397 {
398 	pci_unregister_driver(&i82443bxgx_edacmc_driver);
399 }
400 
401 module_init(i82443bxgx_edacmc_init);
402 module_exit(i82443bxgx_edacmc_exit);
403 
404 MODULE_LICENSE("GPL");
405 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
406 MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
407 
408 module_param(edac_op_state, int, 0444);
409 MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
410