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	edac_dbg(1, "MC%d\n", mci->mc_idx);
180	i82443bxgx_edacmc_get_error_info(mci, &info);
181	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
182}
183
184static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
185				struct pci_dev *pdev,
186				enum edac_type edac_mode,
187				enum mem_type mtype)
188{
189	struct csrow_info *csrow;
190	struct dimm_info *dimm;
191	int index;
192	u8 drbar, dramc;
193	u32 row_base, row_high_limit, row_high_limit_last;
194
195	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
196	row_high_limit_last = 0;
197	for (index = 0; index < mci->nr_csrows; index++) {
198		csrow = mci->csrows[index];
199		dimm = csrow->channels[0]->dimm;
200
201		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
202		edac_dbg(1, "MC%d: Row=%d DRB = %#0x\n",
203			 mci->mc_idx, index, drbar);
204		row_high_limit = ((u32) drbar << 23);
205		/* find the DRAM Chip Select Base address and mask */
206		edac_dbg(1, "MC%d: Row=%d, Boundary Address=%#0x, Last = %#0x\n",
207			 mci->mc_idx, index, row_high_limit,
208			 row_high_limit_last);
209
210		/* 440GX goes to 2GB, represented with a DRB of 0. */
211		if (row_high_limit_last && !row_high_limit)
212			row_high_limit = 1UL << 31;
213
214		/* This row is empty [p.49] */
215		if (row_high_limit == row_high_limit_last)
216			continue;
217		row_base = row_high_limit_last;
218		csrow->first_page = row_base >> PAGE_SHIFT;
219		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
220		dimm->nr_pages = csrow->last_page - csrow->first_page + 1;
221		/* EAP reports in 4kilobyte granularity [61] */
222		dimm->grain = 1 << 12;
223		dimm->mtype = mtype;
224		/* I don't think 440BX can tell you device type? FIXME? */
225		dimm->dtype = DEV_UNKNOWN;
226		/* Mode is global to all rows on 440BX */
227		dimm->edac_mode = edac_mode;
228		row_high_limit_last = row_high_limit;
229	}
230}
231
232static int i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
233{
234	struct mem_ctl_info *mci;
235	struct edac_mc_layer layers[2];
236	u8 dramc;
237	u32 nbxcfg, ecc_mode;
238	enum mem_type mtype;
239	enum edac_type edac_mode;
240
241	edac_dbg(0, "MC:\n");
242
243	/* Something is really hosed if PCI config space reads from
244	 * the MC aren't working.
245	 */
246	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
247		return -EIO;
248
249	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
250	layers[0].size = I82443BXGX_NR_CSROWS;
251	layers[0].is_virt_csrow = true;
252	layers[1].type = EDAC_MC_LAYER_CHANNEL;
253	layers[1].size = I82443BXGX_NR_CHANS;
254	layers[1].is_virt_csrow = false;
255	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
256	if (mci == NULL)
257		return -ENOMEM;
258
259	edac_dbg(0, "MC: mci = %p\n", mci);
260	mci->pdev = &pdev->dev;
261	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
262	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
263	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
264	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
265	case I82443BXGX_DRAMC_DRAM_IS_EDO:
266		mtype = MEM_EDO;
267		break;
268	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
269		mtype = MEM_SDR;
270		break;
271	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
272		mtype = MEM_RDR;
273		break;
274	default:
275		edac_dbg(0, "Unknown/reserved DRAM type value in DRAMC register!\n");
276		mtype = -MEM_UNKNOWN;
277	}
278
279	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
280		mci->edac_cap = mci->edac_ctl_cap;
281	else
282		mci->edac_cap = EDAC_FLAG_NONE;
283
284	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
285	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
286	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
287		(BIT(0) | BIT(1)));
288
289	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
290		? SCRUB_HW_SRC : SCRUB_NONE;
291
292	switch (ecc_mode) {
293	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
294		edac_mode = EDAC_NONE;
295		break;
296	case I82443BXGX_NBXCFG_INTEGRITY_EC:
297		edac_mode = EDAC_EC;
298		break;
299	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
300	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
301		edac_mode = EDAC_SECDED;
302		break;
303	default:
304		edac_dbg(0, "Unknown/reserved ECC state in NBXCFG register!\n");
305		edac_mode = EDAC_UNKNOWN;
306		break;
307	}
308
309	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
310
311	/* Many BIOSes don't clear error flags on boot, so do this
312	 * here, or we get "phantom" errors occurring at module-load
313	 * time. */
314	pci_write_bits32(pdev, I82443BXGX_EAP,
315			(I82443BXGX_EAP_OFFSET_SBE |
316				I82443BXGX_EAP_OFFSET_MBE),
317			(I82443BXGX_EAP_OFFSET_SBE |
318				I82443BXGX_EAP_OFFSET_MBE));
319
320	mci->mod_name = EDAC_MOD_STR;
321	mci->ctl_name = "I82443BXGX";
322	mci->dev_name = pci_name(pdev);
323	mci->edac_check = i82443bxgx_edacmc_check;
324	mci->ctl_page_to_phys = NULL;
325
326	if (edac_mc_add_mc(mci)) {
327		edac_dbg(3, "failed edac_mc_add_mc()\n");
328		goto fail;
329	}
330
331	/* allocating generic PCI control info */
332	i82443bxgx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
333	if (!i82443bxgx_pci) {
334		printk(KERN_WARNING
335			"%s(): Unable to create PCI control\n",
336			__func__);
337		printk(KERN_WARNING
338			"%s(): PCI error report via EDAC not setup\n",
339			__func__);
340	}
341
342	edac_dbg(3, "MC: success\n");
343	return 0;
344
345fail:
346	edac_mc_free(mci);
347	return -ENODEV;
348}
349
350/* returns count (>= 0), or negative on error */
351static int i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
352				      const struct pci_device_id *ent)
353{
354	int rc;
355
356	edac_dbg(0, "MC:\n");
357
358	/* don't need to call pci_enable_device() */
359	rc = i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
360
361	if (mci_pdev == NULL)
362		mci_pdev = pci_dev_get(pdev);
363
364	return rc;
365}
366
367static void i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
368{
369	struct mem_ctl_info *mci;
370
371	edac_dbg(0, "\n");
372
373	if (i82443bxgx_pci)
374		edac_pci_release_generic_ctl(i82443bxgx_pci);
375
376	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
377		return;
378
379	edac_mc_free(mci);
380}
381
382static const struct pci_device_id i82443bxgx_pci_tbl[] = {
383	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
384	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
385	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
386	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
387	{0,}			/* 0 terminated list. */
388};
389
390MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
391
392static struct pci_driver i82443bxgx_edacmc_driver = {
393	.name = EDAC_MOD_STR,
394	.probe = i82443bxgx_edacmc_init_one,
395	.remove = i82443bxgx_edacmc_remove_one,
396	.id_table = i82443bxgx_pci_tbl,
397};
398
399static int __init i82443bxgx_edacmc_init(void)
400{
401	int pci_rc;
402       /* Ensure that the OPSTATE is set correctly for POLL or NMI */
403       opstate_init();
404
405	pci_rc = pci_register_driver(&i82443bxgx_edacmc_driver);
406	if (pci_rc < 0)
407		goto fail0;
408
409	if (mci_pdev == NULL) {
410		const struct pci_device_id *id = &i82443bxgx_pci_tbl[0];
411		int i = 0;
412		i82443bxgx_registered = 0;
413
414		while (mci_pdev == NULL && id->vendor != 0) {
415			mci_pdev = pci_get_device(id->vendor,
416					id->device, NULL);
417			i++;
418			id = &i82443bxgx_pci_tbl[i];
419		}
420		if (!mci_pdev) {
421			edac_dbg(0, "i82443bxgx pci_get_device fail\n");
422			pci_rc = -ENODEV;
423			goto fail1;
424		}
425
426		pci_rc = i82443bxgx_edacmc_init_one(mci_pdev, i82443bxgx_pci_tbl);
427
428		if (pci_rc < 0) {
429			edac_dbg(0, "i82443bxgx init fail\n");
430			pci_rc = -ENODEV;
431			goto fail1;
432		}
433	}
434
435	return 0;
436
437fail1:
438	pci_unregister_driver(&i82443bxgx_edacmc_driver);
439
440fail0:
441	pci_dev_put(mci_pdev);
442	return pci_rc;
443}
444
445static void __exit i82443bxgx_edacmc_exit(void)
446{
447	pci_unregister_driver(&i82443bxgx_edacmc_driver);
448
449	if (!i82443bxgx_registered)
450		i82443bxgx_edacmc_remove_one(mci_pdev);
451
452	pci_dev_put(mci_pdev);
453}
454
455module_init(i82443bxgx_edacmc_init);
456module_exit(i82443bxgx_edacmc_exit);
457
458MODULE_LICENSE("GPL");
459MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
460MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");
461
462module_param(edac_op_state, int, 0444);
463MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");
464