xref: /linux/drivers/edac/r82600_edac.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * Radisys 82600 Embedded chipset Memory Controller kernel module
3  * (C) 2005 EADS Astrium
4  * This file may be distributed under the terms of the
5  * GNU General Public License.
6  *
7  * Written by Tim Small <tim@buttersideup.com>, based on work by Thayne
8  * Harbaugh, Dan Hollis <goemon at anime dot net> and others.
9  *
10  * $Id: edac_r82600.c,v 1.1.2.6 2005/10/05 00:43:44 dsp_llnl Exp $
11  *
12  * Written with reference to 82600 High Integration Dual PCI System
13  * Controller Data Book:
14  * http://www.radisys.com/files/support_downloads/007-01277-0002.82600DataBook.pdf
15  * references to this document given in []
16  */
17 
18 #include <linux/config.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/pci.h>
22 #include <linux/pci_ids.h>
23 #include <linux/slab.h>
24 #include "edac_mc.h"
25 
26 #define r82600_printk(level, fmt, arg...) \
27 	edac_printk(level, "r82600", fmt, ##arg)
28 
29 #define r82600_mc_printk(mci, level, fmt, arg...) \
30 	edac_mc_chipset_printk(mci, level, "r82600", fmt, ##arg)
31 
32 /* Radisys say "The 82600 integrates a main memory SDRAM controller that
33  * supports up to four banks of memory. The four banks can support a mix of
34  * sizes of 64 bit wide (72 bits with ECC) Synchronous DRAM (SDRAM) DIMMs,
35  * each of which can be any size from 16MB to 512MB. Both registered (control
36  * signals buffered) and unbuffered DIMM types are supported. Mixing of
37  * registered and unbuffered DIMMs as well as mixing of ECC and non-ECC DIMMs
38  * is not allowed. The 82600 SDRAM interface operates at the same frequency as
39  * the CPU bus, 66MHz, 100MHz or 133MHz."
40  */
41 
42 #define R82600_NR_CSROWS 4
43 #define R82600_NR_CHANS  1
44 #define R82600_NR_DIMMS  4
45 
46 #define R82600_BRIDGE_ID  0x8200
47 
48 /* Radisys 82600 register addresses - device 0 function 0 - PCI bridge */
49 #define R82600_DRAMC	0x57	/* Various SDRAM related control bits
50 				 * all bits are R/W
51 				 *
52 				 * 7    SDRAM ISA Hole Enable
53 				 * 6    Flash Page Mode Enable
54 				 * 5    ECC Enable: 1=ECC 0=noECC
55 				 * 4    DRAM DIMM Type: 1=
56 				 * 3    BIOS Alias Disable
57 				 * 2    SDRAM BIOS Flash Write Enable
58 				 * 1:0  SDRAM Refresh Rate: 00=Disabled
59 				 *          01=7.8usec (256Mbit SDRAMs)
60 				 *          10=15.6us 11=125usec
61 				 */
62 
63 #define R82600_SDRAMC	0x76	/* "SDRAM Control Register"
64 				 * More SDRAM related control bits
65 				 * all bits are R/W
66 				 *
67 				 * 15:8 Reserved.
68 				 *
69 				 * 7:5  Special SDRAM Mode Select
70 				 *
71 				 * 4    Force ECC
72 				 *
73 				 *        1=Drive ECC bits to 0 during
74 				 *          write cycles (i.e. ECC test mode)
75 				 *
76 				 *        0=Normal ECC functioning
77 				 *
78 				 * 3    Enhanced Paging Enable
79 				 *
80 				 * 2    CAS# Latency 0=3clks 1=2clks
81 				 *
82 				 * 1    RAS# to CAS# Delay 0=3 1=2
83 				 *
84 				 * 0    RAS# Precharge     0=3 1=2
85 				 */
86 
87 #define R82600_EAP	0x80	/* ECC Error Address Pointer Register
88 				 *
89 				 * 31    Disable Hardware Scrubbing (RW)
90 				 *        0=Scrub on corrected read
91 				 *        1=Don't scrub on corrected read
92 				 *
93 				 * 30:12 Error Address Pointer (RO)
94 				 *        Upper 19 bits of error address
95 				 *
96 				 * 11:4  Syndrome Bits (RO)
97 				 *
98 				 * 3     BSERR# on multibit error (RW)
99 				 *        1=enable 0=disable
100 				 *
101 				 * 2     NMI on Single Bit Eror (RW)
102 				 *        1=NMI triggered by SBE n.b. other
103 				 *          prerequeists
104 				 *        0=NMI not triggered
105 				 *
106 				 * 1     MBE (R/WC)
107 				 *        read 1=MBE at EAP (see above)
108 				 *        read 0=no MBE, or SBE occurred first
109 				 *        write 1=Clear MBE status (must also
110 				 *          clear SBE)
111 				 *        write 0=NOP
112 				 *
113 				 * 1     SBE (R/WC)
114 				 *        read 1=SBE at EAP (see above)
115 				 *        read 0=no SBE, or MBE occurred first
116 				 *        write 1=Clear SBE status (must also
117 				 *          clear MBE)
118 				 *        write 0=NOP
119 				 */
120 
121 #define R82600_DRBA	0x60	/* + 0x60..0x63 SDRAM Row Boundry Address
122 				 *  Registers
123 				 *
124 				 * 7:0  Address lines 30:24 - upper limit of
125 				 * each row [p57]
126 				 */
127 
128 struct r82600_error_info {
129 	u32 eapr;
130 };
131 
132 static unsigned int disable_hardware_scrub = 0;
133 
134 static void r82600_get_error_info (struct mem_ctl_info *mci,
135 		struct r82600_error_info *info)
136 {
137 	pci_read_config_dword(mci->pdev, R82600_EAP, &info->eapr);
138 
139 	if (info->eapr & BIT(0))
140 		/* Clear error to allow next error to be reported [p.62] */
141 		pci_write_bits32(mci->pdev, R82600_EAP,
142 				((u32) BIT(0) & (u32) BIT(1)),
143 				((u32) BIT(0) & (u32) BIT(1)));
144 
145 	if (info->eapr & BIT(1))
146 		/* Clear error to allow next error to be reported [p.62] */
147 		pci_write_bits32(mci->pdev, R82600_EAP,
148 				((u32) BIT(0) & (u32) BIT(1)),
149 				((u32) BIT(0) & (u32) BIT(1)));
150 }
151 
152 static int r82600_process_error_info (struct mem_ctl_info *mci,
153 		struct r82600_error_info *info, int handle_errors)
154 {
155 	int error_found;
156 	u32 eapaddr, page;
157 	u32 syndrome;
158 
159 	error_found = 0;
160 
161 	/* bits 30:12 store the upper 19 bits of the 32 bit error address */
162 	eapaddr = ((info->eapr >> 12) & 0x7FFF) << 13;
163 	/* Syndrome in bits 11:4 [p.62]       */
164 	syndrome = (info->eapr >> 4) & 0xFF;
165 
166 	/* the R82600 reports at less than page *
167 	 * granularity (upper 19 bits only)     */
168 	page = eapaddr >> PAGE_SHIFT;
169 
170 	if (info->eapr & BIT(0)) {  /* CE? */
171 		error_found = 1;
172 
173 		if (handle_errors)
174 			edac_mc_handle_ce(mci, page, 0,  /* not avail */
175 					syndrome,
176 					edac_mc_find_csrow_by_page(mci, page),
177 					0,  /* channel */
178 					mci->ctl_name);
179 	}
180 
181 	if (info->eapr & BIT(1)) {  /* UE? */
182 		error_found = 1;
183 
184 		if (handle_errors)
185 			/* 82600 doesn't give enough info */
186 			edac_mc_handle_ue(mci, page, 0,
187 				edac_mc_find_csrow_by_page(mci, page),
188 				mci->ctl_name);
189 	}
190 
191 	return error_found;
192 }
193 
194 static void r82600_check(struct mem_ctl_info *mci)
195 {
196 	struct r82600_error_info info;
197 
198 	debugf1("MC%d: %s()\n", mci->mc_idx, __func__);
199 	r82600_get_error_info(mci, &info);
200 	r82600_process_error_info(mci, &info, 1);
201 }
202 
203 static int r82600_probe1(struct pci_dev *pdev, int dev_idx)
204 {
205 	int rc = -ENODEV;
206 	int index;
207 	struct mem_ctl_info *mci = NULL;
208 	u8 dramcr;
209 	u32 ecc_on;
210 	u32 reg_sdram;
211 	u32 eapr;
212 	u32 scrub_disabled;
213 	u32 sdram_refresh_rate;
214 	u32 row_high_limit_last = 0;
215 	struct r82600_error_info discard;
216 
217 	debugf0("%s()\n", __func__);
218 	pci_read_config_byte(pdev, R82600_DRAMC, &dramcr);
219 	pci_read_config_dword(pdev, R82600_EAP, &eapr);
220 	ecc_on = dramcr & BIT(5);
221 	reg_sdram = dramcr & BIT(4);
222 	scrub_disabled = eapr & BIT(31);
223 	sdram_refresh_rate = dramcr & (BIT(0) | BIT(1));
224 	debugf2("%s(): sdram refresh rate = %#0x\n", __func__,
225 		sdram_refresh_rate);
226 	debugf2("%s(): DRAMC register = %#0x\n", __func__, dramcr);
227 	mci = edac_mc_alloc(0, R82600_NR_CSROWS, R82600_NR_CHANS);
228 
229 	if (mci == NULL) {
230 		rc = -ENOMEM;
231 		goto fail;
232 	}
233 
234 	debugf0("%s(): mci = %p\n", __func__, mci);
235 	mci->pdev = pdev;
236 	mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
237 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
238 	/* FIXME try to work out if the chip leads have been used for COM2
239 	 * instead on this board? [MA6?] MAYBE:
240 	 */
241 
242 	/* On the R82600, the pins for memory bits 72:65 - i.e. the   *
243 	 * EC bits are shared with the pins for COM2 (!), so if COM2  *
244 	 * is enabled, we assume COM2 is wired up, and thus no EDAC   *
245 	 * is possible.                                               */
246 	mci->edac_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
247 
248 	if (ecc_on) {
249 		if (scrub_disabled)
250 			debugf3("%s(): mci = %p - Scrubbing disabled! EAP: "
251 				"%#0x\n", __func__, mci, eapr);
252 	} else
253 		mci->edac_cap = EDAC_FLAG_NONE;
254 
255 	mci->mod_name = EDAC_MOD_STR;
256 	mci->mod_ver = "$Revision: 1.1.2.6 $";
257 	mci->ctl_name = "R82600";
258 	mci->edac_check = r82600_check;
259 	mci->ctl_page_to_phys = NULL;
260 
261 	for (index = 0; index < mci->nr_csrows; index++) {
262 		struct csrow_info *csrow = &mci->csrows[index];
263 		u8 drbar;	/* sDram Row Boundry Address Register */
264 		u32 row_high_limit;
265 		u32 row_base;
266 
267 		/* find the DRAM Chip Select Base address and mask */
268 		pci_read_config_byte(mci->pdev, R82600_DRBA + index, &drbar);
269 
270 		debugf1("MC%d: %s() Row=%d DRBA = %#0x\n", mci->mc_idx,
271 			__func__, index, drbar);
272 
273 		row_high_limit = ((u32) drbar << 24);
274 /*		row_high_limit = ((u32)drbar << 24) | 0xffffffUL; */
275 
276 		debugf1("MC%d: %s() Row=%d, Boundry Address=%#0x, Last = "
277 			"%#0x \n", mci->mc_idx, __func__, index,
278 			row_high_limit, row_high_limit_last);
279 
280 		/* Empty row [p.57] */
281 		if (row_high_limit == row_high_limit_last)
282 			continue;
283 
284 		row_base = row_high_limit_last;
285 		csrow->first_page = row_base >> PAGE_SHIFT;
286 		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
287 		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
288 		/* Error address is top 19 bits - so granularity is      *
289 		 * 14 bits                                               */
290 		csrow->grain = 1 << 14;
291 		csrow->mtype = reg_sdram ? MEM_RDDR : MEM_DDR;
292 		/* FIXME - check that this is unknowable with this chipset */
293 		csrow->dtype = DEV_UNKNOWN;
294 
295 		/* Mode is global on 82600 */
296 		csrow->edac_mode = ecc_on ? EDAC_SECDED : EDAC_NONE;
297 		row_high_limit_last = row_high_limit;
298 	}
299 
300 	r82600_get_error_info(mci, &discard);  /* clear counters */
301 
302 	if (edac_mc_add_mc(mci)) {
303 		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
304 		goto fail;
305 	}
306 
307 	/* get this far and it's successful */
308 
309 	if (disable_hardware_scrub) {
310 		debugf3("%s(): Disabling Hardware Scrub (scrub on error)\n",
311 			__func__);
312 		pci_write_bits32(mci->pdev, R82600_EAP, BIT(31), BIT(31));
313 	}
314 
315 	debugf3("%s(): success\n", __func__);
316 	return 0;
317 
318 fail:
319 	if (mci)
320 		edac_mc_free(mci);
321 
322 	return rc;
323 }
324 
325 /* returns count (>= 0), or negative on error */
326 static int __devinit r82600_init_one(struct pci_dev *pdev,
327 		const struct pci_device_id *ent)
328 {
329 	debugf0("%s()\n", __func__);
330 
331 	/* don't need to call pci_device_enable() */
332 	return r82600_probe1(pdev, ent->driver_data);
333 }
334 
335 static void __devexit r82600_remove_one(struct pci_dev *pdev)
336 {
337 	struct mem_ctl_info *mci;
338 
339 	debugf0("%s()\n", __func__);
340 
341 	if ((mci = edac_mc_del_mc(pdev)) == NULL)
342 		return;
343 
344 	edac_mc_free(mci);
345 }
346 
347 static const struct pci_device_id r82600_pci_tbl[] __devinitdata = {
348 	{
349 		PCI_DEVICE(PCI_VENDOR_ID_RADISYS, R82600_BRIDGE_ID)
350 	},
351 	{
352 		0,
353 	}	/* 0 terminated list. */
354 };
355 
356 MODULE_DEVICE_TABLE(pci, r82600_pci_tbl);
357 
358 static struct pci_driver r82600_driver = {
359 	.name = EDAC_MOD_STR,
360 	.probe = r82600_init_one,
361 	.remove = __devexit_p(r82600_remove_one),
362 	.id_table = r82600_pci_tbl,
363 };
364 
365 static int __init r82600_init(void)
366 {
367 	return pci_register_driver(&r82600_driver);
368 }
369 
370 static void __exit r82600_exit(void)
371 {
372 	pci_unregister_driver(&r82600_driver);
373 }
374 
375 module_init(r82600_init);
376 module_exit(r82600_exit);
377 
378 MODULE_LICENSE("GPL");
379 MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD Ltd. "
380 	"on behalf of EADS Astrium");
381 MODULE_DESCRIPTION("MC support for Radisys 82600 memory controllers");
382 
383 module_param(disable_hardware_scrub, bool, 0644);
384 MODULE_PARM_DESC(disable_hardware_scrub,
385 		 "If set, disable the chipset's automatic scrub for CEs");
386