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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 */
53int 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 */
77static 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 */
100int 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
114static 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 */
144void 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
279done:
280	vfree(buf);
281
282bail:;
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 */
297int 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
427free_bail:
428	vfree(buf);
429bail:
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 */
445void 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