1 /*
2  * Copyright (c) 2012 Intel Corporation. All rights reserved.
3  * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved.
4  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #include <linux/delay.h>
36 #include <linux/pci.h>
37 #include <linux/vmalloc.h>
38 
39 #include "qib.h"
40 
41 /*
42  * Functions specific to the serial EEPROM on cards handled by ib_qib.
43  * The actual serail interface code is in qib_twsi.c. This file is a client
44  */
45 
46 /**
47  * qib_eeprom_read - receives bytes from the eeprom via I2C
48  * @dd: the qlogic_ib device
49  * @eeprom_offset: address to read from
50  * @buffer: where to store result
51  * @len: number of bytes to receive
52  */
53 int qib_eeprom_read(struct qib_devdata *dd, u8 eeprom_offset,
54 		    void *buff, int len)
55 {
56 	int ret;
57 
58 	ret = mutex_lock_interruptible(&dd->eep_lock);
59 	if (!ret) {
60 		ret = qib_twsi_reset(dd);
61 		if (ret)
62 			qib_dev_err(dd, "EEPROM Reset for read failed\n");
63 		else
64 			ret = qib_twsi_blk_rd(dd, dd->twsi_eeprom_dev,
65 					      eeprom_offset, buff, len);
66 		mutex_unlock(&dd->eep_lock);
67 	}
68 
69 	return ret;
70 }
71 
72 /*
73  * Actually update the eeprom, first doing write enable if
74  * needed, then restoring write enable state.
75  * Must be called with eep_lock held
76  */
77 static int eeprom_write_with_enable(struct qib_devdata *dd, u8 offset,
78 		     const void *buf, int len)
79 {
80 	int ret, pwen;
81 
82 	pwen = dd->f_eeprom_wen(dd, 1);
83 	ret = qib_twsi_reset(dd);
84 	if (ret)
85 		qib_dev_err(dd, "EEPROM Reset for write failed\n");
86 	else
87 		ret = qib_twsi_blk_wr(dd, dd->twsi_eeprom_dev,
88 				      offset, buf, len);
89 	dd->f_eeprom_wen(dd, pwen);
90 	return ret;
91 }
92 
93 /**
94  * qib_eeprom_write - writes data to the eeprom via I2C
95  * @dd: the qlogic_ib device
96  * @eeprom_offset: where to place data
97  * @buffer: data to write
98  * @len: number of bytes to write
99  */
100 int qib_eeprom_write(struct qib_devdata *dd, u8 eeprom_offset,
101 		     const void *buff, int len)
102 {
103 	int ret;
104 
105 	ret = mutex_lock_interruptible(&dd->eep_lock);
106 	if (!ret) {
107 		ret = eeprom_write_with_enable(dd, eeprom_offset, buff, len);
108 		mutex_unlock(&dd->eep_lock);
109 	}
110 
111 	return ret;
112 }
113 
114 static u8 flash_csum(struct qib_flash *ifp, int adjust)
115 {
116 	u8 *ip = (u8 *) ifp;
117 	u8 csum = 0, len;
118 
119 	/*
120 	 * Limit length checksummed to max length of actual data.
121 	 * Checksum of erased eeprom will still be bad, but we avoid
122 	 * reading past the end of the buffer we were passed.
123 	 */
124 	len = ifp->if_length;
125 	if (len > sizeof(struct qib_flash))
126 		len = sizeof(struct qib_flash);
127 	while (len--)
128 		csum += *ip++;
129 	csum -= ifp->if_csum;
130 	csum = ~csum;
131 	if (adjust)
132 		ifp->if_csum = csum;
133 
134 	return csum;
135 }
136 
137 /**
138  * qib_get_eeprom_info- get the GUID et al. from the TSWI EEPROM device
139  * @dd: the qlogic_ib device
140  *
141  * We have the capability to use the nguid field, and get
142  * the guid from the first chip's flash, to use for all of them.
143  */
144 void qib_get_eeprom_info(struct qib_devdata *dd)
145 {
146 	void *buf;
147 	struct qib_flash *ifp;
148 	__be64 guid;
149 	int len, eep_stat;
150 	u8 csum, *bguid;
151 	int t = dd->unit;
152 	struct qib_devdata *dd0 = qib_lookup(0);
153 
154 	if (t && dd0->nguid > 1 && t <= dd0->nguid) {
155 		u8 oguid;
156 		dd->base_guid = dd0->base_guid;
157 		bguid = (u8 *) &dd->base_guid;
158 
159 		oguid = bguid[7];
160 		bguid[7] += t;
161 		if (oguid > bguid[7]) {
162 			if (bguid[6] == 0xff) {
163 				if (bguid[5] == 0xff) {
164 					qib_dev_err(dd,
165 						"Can't set %s GUID from base, wraps to OUI!\n",
166 						qib_get_unit_name(t));
167 					dd->base_guid = 0;
168 					goto bail;
169 				}
170 				bguid[5]++;
171 			}
172 			bguid[6]++;
173 		}
174 		dd->nguid = 1;
175 		goto bail;
176 	}
177 
178 	/*
179 	 * Read full flash, not just currently used part, since it may have
180 	 * been written with a newer definition.
181 	 * */
182 	len = sizeof(struct qib_flash);
183 	buf = vmalloc(len);
184 	if (!buf) {
185 		qib_dev_err(dd,
186 			"Couldn't allocate memory to read %u bytes from eeprom for GUID\n",
187 			len);
188 		goto bail;
189 	}
190 
191 	/*
192 	 * Use "public" eeprom read function, which does locking and
193 	 * figures out device. This will migrate to chip-specific.
194 	 */
195 	eep_stat = qib_eeprom_read(dd, 0, buf, len);
196 
197 	if (eep_stat) {
198 		qib_dev_err(dd, "Failed reading GUID from eeprom\n");
199 		goto done;
200 	}
201 	ifp = (struct qib_flash *)buf;
202 
203 	csum = flash_csum(ifp, 0);
204 	if (csum != ifp->if_csum) {
205 		qib_devinfo(dd->pcidev,
206 			"Bad I2C flash checksum: 0x%x, not 0x%x\n",
207 			csum, ifp->if_csum);
208 		goto done;
209 	}
210 	if (*(__be64 *) ifp->if_guid == cpu_to_be64(0) ||
211 	    *(__be64 *) ifp->if_guid == ~cpu_to_be64(0)) {
212 		qib_dev_err(dd,
213 			"Invalid GUID %llx from flash; ignoring\n",
214 			*(unsigned long long *) ifp->if_guid);
215 		/* don't allow GUID if all 0 or all 1's */
216 		goto done;
217 	}
218 
219 	/* complain, but allow it */
220 	if (*(u64 *) ifp->if_guid == 0x100007511000000ULL)
221 		qib_devinfo(dd->pcidev,
222 			"Warning, GUID %llx is default, probably not correct!\n",
223 			*(unsigned long long *) ifp->if_guid);
224 
225 	bguid = ifp->if_guid;
226 	if (!bguid[0] && !bguid[1] && !bguid[2]) {
227 		/*
228 		 * Original incorrect GUID format in flash; fix in
229 		 * core copy, by shifting up 2 octets; don't need to
230 		 * change top octet, since both it and shifted are 0.
231 		 */
232 		bguid[1] = bguid[3];
233 		bguid[2] = bguid[4];
234 		bguid[3] = 0;
235 		bguid[4] = 0;
236 		guid = *(__be64 *) ifp->if_guid;
237 	} else
238 		guid = *(__be64 *) ifp->if_guid;
239 	dd->base_guid = guid;
240 	dd->nguid = ifp->if_numguid;
241 	/*
242 	 * Things are slightly complicated by the desire to transparently
243 	 * support both the Pathscale 10-digit serial number and the QLogic
244 	 * 13-character version.
245 	 */
246 	if ((ifp->if_fversion > 1) && ifp->if_sprefix[0] &&
247 	    ((u8 *) ifp->if_sprefix)[0] != 0xFF) {
248 		char *snp = dd->serial;
249 
250 		/*
251 		 * This board has a Serial-prefix, which is stored
252 		 * elsewhere for backward-compatibility.
253 		 */
254 		memcpy(snp, ifp->if_sprefix, sizeof ifp->if_sprefix);
255 		snp[sizeof ifp->if_sprefix] = '\0';
256 		len = strlen(snp);
257 		snp += len;
258 		len = (sizeof dd->serial) - len;
259 		if (len > sizeof ifp->if_serial)
260 			len = sizeof ifp->if_serial;
261 		memcpy(snp, ifp->if_serial, len);
262 	} else
263 		memcpy(dd->serial, ifp->if_serial,
264 		       sizeof ifp->if_serial);
265 	if (!strstr(ifp->if_comment, "Tested successfully"))
266 		qib_dev_err(dd,
267 			"Board SN %s did not pass functional test: %s\n",
268 			dd->serial, ifp->if_comment);
269 
270 	memcpy(&dd->eep_st_errs, &ifp->if_errcntp, QIB_EEP_LOG_CNT);
271 	/*
272 	 * Power-on (actually "active") hours are kept as little-endian value
273 	 * in EEPROM, but as seconds in a (possibly as small as 24-bit)
274 	 * atomic_t while running.
275 	 */
276 	atomic_set(&dd->active_time, 0);
277 	dd->eep_hrs = ifp->if_powerhour[0] | (ifp->if_powerhour[1] << 8);
278 
279 done:
280 	vfree(buf);
281 
282 bail:;
283 }
284 
285 /**
286  * qib_update_eeprom_log - copy active-time and error counters to eeprom
287  * @dd: the qlogic_ib device
288  *
289  * Although the time is kept as seconds in the qib_devdata struct, it is
290  * rounded to hours for re-write, as we have only 16 bits in EEPROM.
291  * First-cut code reads whole (expected) struct qib_flash, modifies,
292  * re-writes. Future direction: read/write only what we need, assuming
293  * that the EEPROM had to have been "good enough" for driver init, and
294  * if not, we aren't making it worse.
295  *
296  */
297 int qib_update_eeprom_log(struct qib_devdata *dd)
298 {
299 	void *buf;
300 	struct qib_flash *ifp;
301 	int len, hi_water;
302 	uint32_t new_time, new_hrs;
303 	u8 csum;
304 	int ret, idx;
305 	unsigned long flags;
306 
307 	/* first, check if we actually need to do anything. */
308 	ret = 0;
309 	for (idx = 0; idx < QIB_EEP_LOG_CNT; ++idx) {
310 		if (dd->eep_st_new_errs[idx]) {
311 			ret = 1;
312 			break;
313 		}
314 	}
315 	new_time = atomic_read(&dd->active_time);
316 
317 	if (ret == 0 && new_time < 3600)
318 		goto bail;
319 
320 	/*
321 	 * The quick-check above determined that there is something worthy
322 	 * of logging, so get current contents and do a more detailed idea.
323 	 * read full flash, not just currently used part, since it may have
324 	 * been written with a newer definition
325 	 */
326 	len = sizeof(struct qib_flash);
327 	buf = vmalloc(len);
328 	ret = 1;
329 	if (!buf) {
330 		qib_dev_err(dd,
331 			"Couldn't allocate memory to read %u bytes from eeprom for logging\n",
332 			len);
333 		goto bail;
334 	}
335 
336 	/* Grab semaphore and read current EEPROM. If we get an
337 	 * error, let go, but if not, keep it until we finish write.
338 	 */
339 	ret = mutex_lock_interruptible(&dd->eep_lock);
340 	if (ret) {
341 		qib_dev_err(dd, "Unable to acquire EEPROM for logging\n");
342 		goto free_bail;
343 	}
344 	ret = qib_twsi_blk_rd(dd, dd->twsi_eeprom_dev, 0, buf, len);
345 	if (ret) {
346 		mutex_unlock(&dd->eep_lock);
347 		qib_dev_err(dd, "Unable read EEPROM for logging\n");
348 		goto free_bail;
349 	}
350 	ifp = (struct qib_flash *)buf;
351 
352 	csum = flash_csum(ifp, 0);
353 	if (csum != ifp->if_csum) {
354 		mutex_unlock(&dd->eep_lock);
355 		qib_dev_err(dd, "EEPROM cks err (0x%02X, S/B 0x%02X)\n",
356 			    csum, ifp->if_csum);
357 		ret = 1;
358 		goto free_bail;
359 	}
360 	hi_water = 0;
361 	spin_lock_irqsave(&dd->eep_st_lock, flags);
362 	for (idx = 0; idx < QIB_EEP_LOG_CNT; ++idx) {
363 		int new_val = dd->eep_st_new_errs[idx];
364 		if (new_val) {
365 			/*
366 			 * If we have seen any errors, add to EEPROM values
367 			 * We need to saturate at 0xFF (255) and we also
368 			 * would need to adjust the checksum if we were
369 			 * trying to minimize EEPROM traffic
370 			 * Note that we add to actual current count in EEPROM,
371 			 * in case it was altered while we were running.
372 			 */
373 			new_val += ifp->if_errcntp[idx];
374 			if (new_val > 0xFF)
375 				new_val = 0xFF;
376 			if (ifp->if_errcntp[idx] != new_val) {
377 				ifp->if_errcntp[idx] = new_val;
378 				hi_water = offsetof(struct qib_flash,
379 						    if_errcntp) + idx;
380 			}
381 			/*
382 			 * update our shadow (used to minimize EEPROM
383 			 * traffic), to match what we are about to write.
384 			 */
385 			dd->eep_st_errs[idx] = new_val;
386 			dd->eep_st_new_errs[idx] = 0;
387 		}
388 	}
389 	/*
390 	 * Now update active-time. We would like to round to the nearest hour
391 	 * but unless atomic_t are sure to be proper signed ints we cannot,
392 	 * because we need to account for what we "transfer" to EEPROM and
393 	 * if we log an hour at 31 minutes, then we would need to set
394 	 * active_time to -29 to accurately count the _next_ hour.
395 	 */
396 	if (new_time >= 3600) {
397 		new_hrs = new_time / 3600;
398 		atomic_sub((new_hrs * 3600), &dd->active_time);
399 		new_hrs += dd->eep_hrs;
400 		if (new_hrs > 0xFFFF)
401 			new_hrs = 0xFFFF;
402 		dd->eep_hrs = new_hrs;
403 		if ((new_hrs & 0xFF) != ifp->if_powerhour[0]) {
404 			ifp->if_powerhour[0] = new_hrs & 0xFF;
405 			hi_water = offsetof(struct qib_flash, if_powerhour);
406 		}
407 		if ((new_hrs >> 8) != ifp->if_powerhour[1]) {
408 			ifp->if_powerhour[1] = new_hrs >> 8;
409 			hi_water = offsetof(struct qib_flash, if_powerhour) + 1;
410 		}
411 	}
412 	/*
413 	 * There is a tiny possibility that we could somehow fail to write
414 	 * the EEPROM after updating our shadows, but problems from holding
415 	 * the spinlock too long are a much bigger issue.
416 	 */
417 	spin_unlock_irqrestore(&dd->eep_st_lock, flags);
418 	if (hi_water) {
419 		/* we made some change to the data, uopdate cksum and write */
420 		csum = flash_csum(ifp, 1);
421 		ret = eeprom_write_with_enable(dd, 0, buf, hi_water + 1);
422 	}
423 	mutex_unlock(&dd->eep_lock);
424 	if (ret)
425 		qib_dev_err(dd, "Failed updating EEPROM\n");
426 
427 free_bail:
428 	vfree(buf);
429 bail:
430 	return ret;
431 }
432 
433 /**
434  * qib_inc_eeprom_err - increment one of the four error counters
435  * that are logged to EEPROM.
436  * @dd: the qlogic_ib device
437  * @eidx: 0..3, the counter to increment
438  * @incr: how much to add
439  *
440  * Each counter is 8-bits, and saturates at 255 (0xFF). They
441  * are copied to the EEPROM (aka flash) whenever qib_update_eeprom_log()
442  * is called, but it can only be called in a context that allows sleep.
443  * This function can be called even at interrupt level.
444  */
445 void qib_inc_eeprom_err(struct qib_devdata *dd, u32 eidx, u32 incr)
446 {
447 	uint new_val;
448 	unsigned long flags;
449 
450 	spin_lock_irqsave(&dd->eep_st_lock, flags);
451 	new_val = dd->eep_st_new_errs[eidx] + incr;
452 	if (new_val > 255)
453 		new_val = 255;
454 	dd->eep_st_new_errs[eidx] = new_val;
455 	spin_unlock_irqrestore(&dd->eep_st_lock, flags);
456 }
457