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
108struct i82443bxgx_edacmc_error_info {
109	u32 eap;
110};
111
112static struct edac_pci_ctl_info *i82443bxgx_pci;
113
114static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
115					 * already registered driver
116					 */
117
118static int i82443bxgx_registered = 1;
119
120static 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
140static 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
175static 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
183static 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
231static 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
344fail:
345	edac_mc_free(mci);
346	return -ENODEV;
347}
348
349/* returns count (>= 0), or negative on error */
350static 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
366static 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
381static 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
389MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
390
391static 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
398static 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
436fail1:
437	pci_unregister_driver(&i82443bxgx_edacmc_driver);
438
439fail0:
440	pci_dev_put(mci_pdev);
441	return pci_rc;
442}
443
444static 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
454module_init(i82443bxgx_edacmc_init);
455module_exit(i82443bxgx_edacmc_exit);
456
457MODULE_LICENSE("GPL");
458MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
459MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
460
461module_param(edac_op_state, int, 0444);
462MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
463