]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blob - drivers/infiniband/hw/ipath/ipath_intr.c
92e58c921522c2e1eae807e077b9322e65c74ae3
[linux-2.6-omap-h63xx.git] / drivers / infiniband / hw / ipath / ipath_intr.c
1 /*
2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
3  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33
34 #include <linux/pci.h>
35
36 #include "ipath_kernel.h"
37 #include "ipath_verbs.h"
38 #include "ipath_common.h"
39
40 /*
41  * clear (write) a pio buffer, to clear a parity error.   This routine
42  * should only be called when in freeze mode, and the buffer should be
43  * canceled afterwards.
44  */
45 static void ipath_clrpiobuf(struct ipath_devdata *dd, u32 pnum)
46 {
47         u32 __iomem *pbuf;
48         u32 dwcnt; /* dword count to write */
49         if (pnum < dd->ipath_piobcnt2k) {
50                 pbuf = (u32 __iomem *) (dd->ipath_pio2kbase + pnum *
51                         dd->ipath_palign);
52                 dwcnt = dd->ipath_piosize2k >> 2;
53         }
54         else {
55                 pbuf = (u32 __iomem *) (dd->ipath_pio4kbase +
56                         (pnum - dd->ipath_piobcnt2k) * dd->ipath_4kalign);
57                 dwcnt = dd->ipath_piosize4k >> 2;
58         }
59         dev_info(&dd->pcidev->dev,
60                 "Rewrite PIO buffer %u, to recover from parity error\n",
61                 pnum);
62         *pbuf = dwcnt+1; /* no flush required, since already in freeze */
63         while(--dwcnt)
64                 *pbuf++ = 0;
65 }
66
67 /*
68  * Called when we might have an error that is specific to a particular
69  * PIO buffer, and may need to cancel that buffer, so it can be re-used.
70  * If rewrite is true, and bits are set in the sendbufferror registers,
71  * we'll write to the buffer, for error recovery on parity errors.
72  */
73 static void ipath_disarm_senderrbufs(struct ipath_devdata *dd, int rewrite)
74 {
75         u32 piobcnt;
76         unsigned long sbuf[4];
77         /*
78          * it's possible that sendbuffererror could have bits set; might
79          * have already done this as a result of hardware error handling
80          */
81         piobcnt = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
82         /* read these before writing errorclear */
83         sbuf[0] = ipath_read_kreg64(
84                 dd, dd->ipath_kregs->kr_sendbuffererror);
85         sbuf[1] = ipath_read_kreg64(
86                 dd, dd->ipath_kregs->kr_sendbuffererror + 1);
87         if (piobcnt > 128) {
88                 sbuf[2] = ipath_read_kreg64(
89                         dd, dd->ipath_kregs->kr_sendbuffererror + 2);
90                 sbuf[3] = ipath_read_kreg64(
91                         dd, dd->ipath_kregs->kr_sendbuffererror + 3);
92         }
93
94         if (sbuf[0] || sbuf[1] || (piobcnt > 128 && (sbuf[2] || sbuf[3]))) {
95                 int i;
96                 if (ipath_debug & (__IPATH_PKTDBG|__IPATH_DBG) &&
97                         dd->ipath_lastcancel > jiffies) {
98                         __IPATH_DBG_WHICH(__IPATH_PKTDBG|__IPATH_DBG,
99                                           "SendbufErrs %lx %lx", sbuf[0],
100                                           sbuf[1]);
101                         if (ipath_debug & __IPATH_PKTDBG && piobcnt > 128)
102                                 printk(" %lx %lx ", sbuf[2], sbuf[3]);
103                         printk("\n");
104                 }
105
106                 for (i = 0; i < piobcnt; i++)
107                         if (test_bit(i, sbuf)) {
108                                 if (rewrite)
109                                         ipath_clrpiobuf(dd, i);
110                                 ipath_disarm_piobufs(dd, i, 1);
111                         }
112                 /* ignore armlaunch errs for a bit */
113                 dd->ipath_lastcancel = jiffies+3;
114         }
115 }
116
117
118 /* These are all rcv-related errors which we want to count for stats */
119 #define E_SUM_PKTERRS \
120         (INFINIPATH_E_RHDRLEN | INFINIPATH_E_RBADTID | \
121          INFINIPATH_E_RBADVERSION | INFINIPATH_E_RHDR | \
122          INFINIPATH_E_RLONGPKTLEN | INFINIPATH_E_RSHORTPKTLEN | \
123          INFINIPATH_E_RMAXPKTLEN | INFINIPATH_E_RMINPKTLEN | \
124          INFINIPATH_E_RFORMATERR | INFINIPATH_E_RUNSUPVL | \
125          INFINIPATH_E_RUNEXPCHAR | INFINIPATH_E_REBP)
126
127 /* These are all send-related errors which we want to count for stats */
128 #define E_SUM_ERRS \
129         (INFINIPATH_E_SPIOARMLAUNCH | INFINIPATH_E_SUNEXPERRPKTNUM | \
130          INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
131          INFINIPATH_E_SMAXPKTLEN | INFINIPATH_E_SUNSUPVL | \
132          INFINIPATH_E_SMINPKTLEN | INFINIPATH_E_SPKTLEN | \
133          INFINIPATH_E_INVALIDADDR)
134
135 /*
136  * this is similar to E_SUM_ERRS, but can't ignore armlaunch, don't ignore
137  * errors not related to freeze and cancelling buffers.  Can't ignore
138  * armlaunch because could get more while still cleaning up, and need
139  * to cancel those as they happen.
140  */
141 #define E_SPKT_ERRS_IGNORE \
142          (INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
143          INFINIPATH_E_SMAXPKTLEN | INFINIPATH_E_SMINPKTLEN | \
144          INFINIPATH_E_SPKTLEN)
145
146 /*
147  * these are errors that can occur when the link changes state while
148  * a packet is being sent or received.  This doesn't cover things
149  * like EBP or VCRC that can be the result of a sending having the
150  * link change state, so we receive a "known bad" packet.
151  */
152 #define E_SUM_LINK_PKTERRS \
153         (INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
154          INFINIPATH_E_SMINPKTLEN | INFINIPATH_E_SPKTLEN | \
155          INFINIPATH_E_RSHORTPKTLEN | INFINIPATH_E_RMINPKTLEN | \
156          INFINIPATH_E_RUNEXPCHAR)
157
158 static u64 handle_e_sum_errs(struct ipath_devdata *dd, ipath_err_t errs)
159 {
160         u64 ignore_this_time = 0;
161
162         ipath_disarm_senderrbufs(dd, 0);
163         if ((errs & E_SUM_LINK_PKTERRS) &&
164             !(dd->ipath_flags & IPATH_LINKACTIVE)) {
165                 /*
166                  * This can happen when SMA is trying to bring the link
167                  * up, but the IB link changes state at the "wrong" time.
168                  * The IB logic then complains that the packet isn't
169                  * valid.  We don't want to confuse people, so we just
170                  * don't print them, except at debug
171                  */
172                 ipath_dbg("Ignoring packet errors %llx, because link not "
173                           "ACTIVE\n", (unsigned long long) errs);
174                 ignore_this_time = errs & E_SUM_LINK_PKTERRS;
175         }
176
177         return ignore_this_time;
178 }
179
180 /* generic hw error messages... */
181 #define INFINIPATH_HWE_TXEMEMPARITYERR_MSG(a) \
182         { \
183                 .mask = ( INFINIPATH_HWE_TXEMEMPARITYERR_##a <<    \
184                           INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT ),   \
185                 .msg = "TXE " #a " Memory Parity"            \
186         }
187 #define INFINIPATH_HWE_RXEMEMPARITYERR_MSG(a) \
188         { \
189                 .mask = ( INFINIPATH_HWE_RXEMEMPARITYERR_##a <<    \
190                           INFINIPATH_HWE_RXEMEMPARITYERR_SHIFT ),   \
191                 .msg = "RXE " #a " Memory Parity"            \
192         }
193
194 static const struct ipath_hwerror_msgs ipath_generic_hwerror_msgs[] = {
195         INFINIPATH_HWE_MSG(IBCBUSFRSPCPARITYERR, "IPATH2IB Parity"),
196         INFINIPATH_HWE_MSG(IBCBUSTOSPCPARITYERR, "IB2IPATH Parity"),
197
198         INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOBUF),
199         INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOPBC),
200         INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOLAUNCHFIFO),
201
202         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(RCVBUF),
203         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(LOOKUPQ),
204         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(EAGERTID),
205         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(EXPTID),
206         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(FLAGBUF),
207         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(DATAINFO),
208         INFINIPATH_HWE_RXEMEMPARITYERR_MSG(HDRINFO),
209 };
210
211 /**
212  * ipath_format_hwmsg - format a single hwerror message
213  * @msg message buffer
214  * @msgl length of message buffer
215  * @hwmsg message to add to message buffer
216  */
217 static void ipath_format_hwmsg(char *msg, size_t msgl, const char *hwmsg)
218 {
219         strlcat(msg, "[", msgl);
220         strlcat(msg, hwmsg, msgl);
221         strlcat(msg, "]", msgl);
222 }
223
224 /**
225  * ipath_format_hwerrors - format hardware error messages for display
226  * @hwerrs hardware errors bit vector
227  * @hwerrmsgs hardware error descriptions
228  * @nhwerrmsgs number of hwerrmsgs
229  * @msg message buffer
230  * @msgl message buffer length
231  */
232 void ipath_format_hwerrors(u64 hwerrs,
233                            const struct ipath_hwerror_msgs *hwerrmsgs,
234                            size_t nhwerrmsgs,
235                            char *msg, size_t msgl)
236 {
237         int i;
238         const int glen =
239             sizeof(ipath_generic_hwerror_msgs) /
240             sizeof(ipath_generic_hwerror_msgs[0]);
241
242         for (i=0; i<glen; i++) {
243                 if (hwerrs & ipath_generic_hwerror_msgs[i].mask) {
244                         ipath_format_hwmsg(msg, msgl,
245                                            ipath_generic_hwerror_msgs[i].msg);
246                 }
247         }
248
249         for (i=0; i<nhwerrmsgs; i++) {
250                 if (hwerrs & hwerrmsgs[i].mask) {
251                         ipath_format_hwmsg(msg, msgl, hwerrmsgs[i].msg);
252                 }
253         }
254 }
255
256 /* return the strings for the most common link states */
257 static char *ib_linkstate(u32 linkstate)
258 {
259         char *ret;
260
261         switch (linkstate) {
262         case IPATH_IBSTATE_INIT:
263                 ret = "Init";
264                 break;
265         case IPATH_IBSTATE_ARM:
266                 ret = "Arm";
267                 break;
268         case IPATH_IBSTATE_ACTIVE:
269                 ret = "Active";
270                 break;
271         default:
272                 ret = "Down";
273         }
274
275         return ret;
276 }
277
278 void signal_ib_event(struct ipath_devdata *dd, enum ib_event_type ev)
279 {
280         struct ib_event event;
281
282         event.device = &dd->verbs_dev->ibdev;
283         event.element.port_num = 1;
284         event.event = ev;
285         ib_dispatch_event(&event);
286 }
287
288 static void handle_e_ibstatuschanged(struct ipath_devdata *dd,
289                                      ipath_err_t errs, int noprint)
290 {
291         u64 val;
292         u32 ltstate, lstate;
293
294         /*
295          * even if diags are enabled, we want to notice LINKINIT, etc.
296          * We just don't want to change the LED state, or
297          * dd->ipath_kregs->kr_ibcctrl
298          */
299         val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
300         lstate = val & IPATH_IBSTATE_MASK;
301
302         /*
303          * this is confusing enough when it happens that I want to always put it
304          * on the console and in the logs.  If it was a requested state change,
305          * we'll have already cleared the flags, so we won't print this warning
306          */
307         if ((lstate != IPATH_IBSTATE_ARM && lstate != IPATH_IBSTATE_ACTIVE)
308                 && (dd->ipath_flags & (IPATH_LINKARMED | IPATH_LINKACTIVE))) {
309                 dev_info(&dd->pcidev->dev, "Link state changed from %s to %s\n",
310                                  (dd->ipath_flags & IPATH_LINKARMED) ? "ARM" : "ACTIVE",
311                                  ib_linkstate(lstate));
312                 /*
313                  * Flush all queued sends when link went to DOWN or INIT,
314                  * to be sure that they don't block SMA and other MAD packets
315                  */
316                 ipath_cancel_sends(dd, 1);
317         }
318         else if (lstate == IPATH_IBSTATE_INIT || lstate == IPATH_IBSTATE_ARM ||
319             lstate == IPATH_IBSTATE_ACTIVE) {
320                 /*
321                  * only print at SMA if there is a change, debug if not
322                  * (sometimes we want to know that, usually not).
323                  */
324                 if (lstate == ((unsigned) dd->ipath_lastibcstat
325                                & IPATH_IBSTATE_MASK)) {
326                         ipath_dbg("Status change intr but no change (%s)\n",
327                                   ib_linkstate(lstate));
328                 }
329                 else
330                         ipath_cdbg(VERBOSE, "Unit %u link state %s, last "
331                                    "was %s\n", dd->ipath_unit,
332                                    ib_linkstate(lstate),
333                                    ib_linkstate((unsigned)
334                                                 dd->ipath_lastibcstat
335                                                 & IPATH_IBSTATE_MASK));
336         }
337         else {
338                 lstate = dd->ipath_lastibcstat & IPATH_IBSTATE_MASK;
339                 if (lstate == IPATH_IBSTATE_INIT ||
340                     lstate == IPATH_IBSTATE_ARM ||
341                     lstate == IPATH_IBSTATE_ACTIVE)
342                         ipath_cdbg(VERBOSE, "Unit %u link state down"
343                                    " (state 0x%x), from %s\n",
344                                    dd->ipath_unit,
345                                    (u32)val & IPATH_IBSTATE_MASK,
346                                    ib_linkstate(lstate));
347                 else
348                         ipath_cdbg(VERBOSE, "Unit %u link state changed "
349                                    "to 0x%x from down (%x)\n",
350                                    dd->ipath_unit, (u32) val, lstate);
351         }
352         ltstate = (val >> INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT) &
353                 INFINIPATH_IBCS_LINKTRAININGSTATE_MASK;
354         lstate = (val >> INFINIPATH_IBCS_LINKSTATE_SHIFT) &
355                 INFINIPATH_IBCS_LINKSTATE_MASK;
356
357         if (ltstate == INFINIPATH_IBCS_LT_STATE_POLLACTIVE ||
358             ltstate == INFINIPATH_IBCS_LT_STATE_POLLQUIET) {
359                 u32 last_ltstate;
360
361                 /*
362                  * Ignore cycling back and forth from Polling.Active
363                  * to Polling.Quiet while waiting for the other end of
364                  * the link to come up. We will cycle back and forth
365                  * between them if no cable is plugged in,
366                  * the other device is powered off or disabled, etc.
367                  */
368                 last_ltstate = (dd->ipath_lastibcstat >>
369                                 INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT)
370                         & INFINIPATH_IBCS_LINKTRAININGSTATE_MASK;
371                 if (last_ltstate == INFINIPATH_IBCS_LT_STATE_POLLACTIVE
372                     || last_ltstate ==
373                     INFINIPATH_IBCS_LT_STATE_POLLQUIET) {
374                         if (dd->ipath_ibpollcnt > 40) {
375                                 dd->ipath_flags |= IPATH_NOCABLE;
376                                 *dd->ipath_statusp |=
377                                         IPATH_STATUS_IB_NOCABLE;
378                         } else
379                                 dd->ipath_ibpollcnt++;
380                         goto skip_ibchange;
381                 }
382         }
383         dd->ipath_ibpollcnt = 0;        /* some state other than 2 or 3 */
384         ipath_stats.sps_iblink++;
385         if (ltstate != INFINIPATH_IBCS_LT_STATE_LINKUP) {
386                 if (dd->ipath_flags & IPATH_LINKACTIVE)
387                         signal_ib_event(dd, IB_EVENT_PORT_ERR);
388                 dd->ipath_flags |= IPATH_LINKDOWN;
389                 dd->ipath_flags &= ~(IPATH_LINKUNK | IPATH_LINKINIT
390                                      | IPATH_LINKACTIVE |
391                                      IPATH_LINKARMED);
392                 *dd->ipath_statusp &= ~IPATH_STATUS_IB_READY;
393                 dd->ipath_lli_counter = 0;
394                 if (!noprint) {
395                         if (((dd->ipath_lastibcstat >>
396                               INFINIPATH_IBCS_LINKSTATE_SHIFT) &
397                              INFINIPATH_IBCS_LINKSTATE_MASK)
398                             == INFINIPATH_IBCS_L_STATE_ACTIVE)
399                                 /* if from up to down be more vocal */
400                                 ipath_cdbg(VERBOSE,
401                                            "Unit %u link now down (%s)\n",
402                                            dd->ipath_unit,
403                                            ipath_ibcstatus_str[ltstate]);
404                         else
405                                 ipath_cdbg(VERBOSE, "Unit %u link is "
406                                            "down (%s)\n", dd->ipath_unit,
407                                            ipath_ibcstatus_str[ltstate]);
408                 }
409
410                 dd->ipath_f_setextled(dd, lstate, ltstate);
411         } else if ((val & IPATH_IBSTATE_MASK) == IPATH_IBSTATE_ACTIVE) {
412                 dd->ipath_flags |= IPATH_LINKACTIVE;
413                 dd->ipath_flags &=
414                         ~(IPATH_LINKUNK | IPATH_LINKINIT | IPATH_LINKDOWN |
415                           IPATH_LINKARMED | IPATH_NOCABLE);
416                 *dd->ipath_statusp &= ~IPATH_STATUS_IB_NOCABLE;
417                 *dd->ipath_statusp |=
418                         IPATH_STATUS_IB_READY | IPATH_STATUS_IB_CONF;
419                 dd->ipath_f_setextled(dd, lstate, ltstate);
420                 signal_ib_event(dd, IB_EVENT_PORT_ACTIVE);
421         } else if ((val & IPATH_IBSTATE_MASK) == IPATH_IBSTATE_INIT) {
422                 if (dd->ipath_flags & IPATH_LINKACTIVE)
423                         signal_ib_event(dd, IB_EVENT_PORT_ERR);
424                 /*
425                  * set INIT and DOWN.  Down is checked by most of the other
426                  * code, but INIT is useful to know in a few places.
427                  */
428                 dd->ipath_flags |= IPATH_LINKINIT | IPATH_LINKDOWN;
429                 dd->ipath_flags &=
430                         ~(IPATH_LINKUNK | IPATH_LINKACTIVE | IPATH_LINKARMED
431                           | IPATH_NOCABLE);
432                 *dd->ipath_statusp &= ~(IPATH_STATUS_IB_NOCABLE
433                                         | IPATH_STATUS_IB_READY);
434                 dd->ipath_f_setextled(dd, lstate, ltstate);
435         } else if ((val & IPATH_IBSTATE_MASK) == IPATH_IBSTATE_ARM) {
436                 if (dd->ipath_flags & IPATH_LINKACTIVE)
437                         signal_ib_event(dd, IB_EVENT_PORT_ERR);
438                 dd->ipath_flags |= IPATH_LINKARMED;
439                 dd->ipath_flags &=
440                         ~(IPATH_LINKUNK | IPATH_LINKDOWN | IPATH_LINKINIT |
441                           IPATH_LINKACTIVE | IPATH_NOCABLE);
442                 *dd->ipath_statusp &= ~(IPATH_STATUS_IB_NOCABLE
443                                         | IPATH_STATUS_IB_READY);
444                 dd->ipath_f_setextled(dd, lstate, ltstate);
445         } else {
446                 if (!noprint)
447                         ipath_dbg("IBstatuschange unit %u: %s (%x)\n",
448                                   dd->ipath_unit,
449                                   ipath_ibcstatus_str[ltstate], ltstate);
450         }
451 skip_ibchange:
452         dd->ipath_lastibcstat = val;
453 }
454
455 static void handle_supp_msgs(struct ipath_devdata *dd,
456                              unsigned supp_msgs, char *msg, int msgsz)
457 {
458         /*
459          * Print the message unless it's ibc status change only, which
460          * happens so often we never want to count it.
461          */
462         if (dd->ipath_lasterror & ~INFINIPATH_E_IBSTATUSCHANGED) {
463                 int iserr;
464                 iserr = ipath_decode_err(msg, msgsz,
465                                          dd->ipath_lasterror &
466                                          ~INFINIPATH_E_IBSTATUSCHANGED);
467                 if (dd->ipath_lasterror &
468                         ~(INFINIPATH_E_RRCVEGRFULL |
469                         INFINIPATH_E_RRCVHDRFULL | INFINIPATH_E_PKTERRS))
470                         ipath_dev_err(dd, "Suppressed %u messages for "
471                                       "fast-repeating errors (%s) (%llx)\n",
472                                       supp_msgs, msg,
473                                       (unsigned long long)
474                                       dd->ipath_lasterror);
475                 else {
476                         /*
477                          * rcvegrfull and rcvhdrqfull are "normal", for some
478                          * types of processes (mostly benchmarks) that send
479                          * huge numbers of messages, while not processing
480                          * them. So only complain about these at debug
481                          * level.
482                          */
483                         if (iserr)
484                                 ipath_dbg("Suppressed %u messages for %s\n",
485                                           supp_msgs, msg);
486                         else
487                                 ipath_cdbg(ERRPKT,
488                                         "Suppressed %u messages for %s\n",
489                                           supp_msgs, msg);
490                 }
491         }
492 }
493
494 static unsigned handle_frequent_errors(struct ipath_devdata *dd,
495                                        ipath_err_t errs, char *msg,
496                                        int msgsz, int *noprint)
497 {
498         unsigned long nc;
499         static unsigned long nextmsg_time;
500         static unsigned nmsgs, supp_msgs;
501
502         /*
503          * Throttle back "fast" messages to no more than 10 per 5 seconds.
504          * This isn't perfect, but it's a reasonable heuristic. If we get
505          * more than 10, give a 6x longer delay.
506          */
507         nc = jiffies;
508         if (nmsgs > 10) {
509                 if (time_before(nc, nextmsg_time)) {
510                         *noprint = 1;
511                         if (!supp_msgs++)
512                                 nextmsg_time = nc + HZ * 3;
513                 }
514                 else if (supp_msgs) {
515                         handle_supp_msgs(dd, supp_msgs, msg, msgsz);
516                         supp_msgs = 0;
517                         nmsgs = 0;
518                 }
519         }
520         else if (!nmsgs++ || time_after(nc, nextmsg_time))
521                 nextmsg_time = nc + HZ / 2;
522
523         return supp_msgs;
524 }
525
526 static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
527 {
528         char msg[128];
529         u64 ignore_this_time = 0;
530         int i, iserr = 0;
531         int chkerrpkts = 0, noprint = 0;
532         unsigned supp_msgs;
533         int log_idx;
534
535         supp_msgs = handle_frequent_errors(dd, errs, msg, sizeof msg, &noprint);
536
537         /* don't report errors that are masked */
538         errs &= ~dd->ipath_maskederrs;
539
540         /* do these first, they are most important */
541         if (errs & INFINIPATH_E_HARDWARE) {
542                 /* reuse same msg buf */
543                 dd->ipath_f_handle_hwerrors(dd, msg, sizeof msg);
544         } else {
545                 u64 mask;
546                 for (log_idx = 0; log_idx < IPATH_EEP_LOG_CNT; ++log_idx) {
547                         mask = dd->ipath_eep_st_masks[log_idx].errs_to_log;
548                         if (errs & mask)
549                                 ipath_inc_eeprom_err(dd, log_idx, 1);
550                 }
551         }
552
553         if (!noprint && (errs & ~dd->ipath_e_bitsextant))
554                 ipath_dev_err(dd, "error interrupt with unknown errors "
555                               "%llx set\n", (unsigned long long)
556                               (errs & ~dd->ipath_e_bitsextant));
557
558         if (errs & E_SUM_ERRS)
559                 ignore_this_time = handle_e_sum_errs(dd, errs);
560         else if ((errs & E_SUM_LINK_PKTERRS) &&
561             !(dd->ipath_flags & IPATH_LINKACTIVE)) {
562                 /*
563                  * This can happen when SMA is trying to bring the link
564                  * up, but the IB link changes state at the "wrong" time.
565                  * The IB logic then complains that the packet isn't
566                  * valid.  We don't want to confuse people, so we just
567                  * don't print them, except at debug
568                  */
569                 ipath_dbg("Ignoring packet errors %llx, because link not "
570                           "ACTIVE\n", (unsigned long long) errs);
571                 ignore_this_time = errs & E_SUM_LINK_PKTERRS;
572         }
573
574         if (supp_msgs == 250000) {
575                 int s_iserr;
576                 /*
577                  * It's not entirely reasonable assuming that the errors set
578                  * in the last clear period are all responsible for the
579                  * problem, but the alternative is to assume it's the only
580                  * ones on this particular interrupt, which also isn't great
581                  */
582                 dd->ipath_maskederrs |= dd->ipath_lasterror | errs;
583                 dd->ipath_errormask &= ~dd->ipath_maskederrs;
584                 ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
585                         dd->ipath_errormask);
586                 s_iserr = ipath_decode_err(msg, sizeof msg,
587                         dd->ipath_maskederrs);
588
589                 if (dd->ipath_maskederrs &
590                         ~(INFINIPATH_E_RRCVEGRFULL |
591                         INFINIPATH_E_RRCVHDRFULL | INFINIPATH_E_PKTERRS))
592                         ipath_dev_err(dd, "Temporarily disabling "
593                             "error(s) %llx reporting; too frequent (%s)\n",
594                                 (unsigned long long)dd->ipath_maskederrs,
595                                 msg);
596                 else {
597                         /*
598                          * rcvegrfull and rcvhdrqfull are "normal",
599                          * for some types of processes (mostly benchmarks)
600                          * that send huge numbers of messages, while not
601                          * processing them.  So only complain about
602                          * these at debug level.
603                          */
604                         if (s_iserr)
605                                 ipath_dbg("Temporarily disabling reporting "
606                                     "too frequent queue full errors (%s)\n",
607                                     msg);
608                         else
609                                 ipath_cdbg(ERRPKT,
610                                     "Temporarily disabling reporting too"
611                                     " frequent packet errors (%s)\n",
612                                     msg);
613                 }
614
615                 /*
616                  * Re-enable the masked errors after around 3 minutes.  in
617                  * ipath_get_faststats().  If we have a series of fast
618                  * repeating but different errors, the interval will keep
619                  * stretching out, but that's OK, as that's pretty
620                  * catastrophic.
621                  */
622                 dd->ipath_unmasktime = jiffies + HZ * 180;
623         }
624
625         ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear, errs);
626         if (ignore_this_time)
627                 errs &= ~ignore_this_time;
628         if (errs & ~dd->ipath_lasterror) {
629                 errs &= ~dd->ipath_lasterror;
630                 /* never suppress duplicate hwerrors or ibstatuschange */
631                 dd->ipath_lasterror |= errs &
632                         ~(INFINIPATH_E_HARDWARE |
633                           INFINIPATH_E_IBSTATUSCHANGED);
634         }
635
636         /* likely due to cancel, so suppress */
637         if ((errs & (INFINIPATH_E_SPKTLEN | INFINIPATH_E_SPIOARMLAUNCH)) &&
638                 dd->ipath_lastcancel > jiffies) {
639                 ipath_dbg("Suppressed armlaunch/spktlen after error send cancel\n");
640                 errs &= ~(INFINIPATH_E_SPIOARMLAUNCH | INFINIPATH_E_SPKTLEN);
641         }
642
643         if (!errs)
644                 return 0;
645
646         if (!noprint)
647                 /*
648                  * the ones we mask off are handled specially below or above
649                  */
650                 ipath_decode_err(msg, sizeof msg,
651                                  errs & ~(INFINIPATH_E_IBSTATUSCHANGED |
652                                           INFINIPATH_E_RRCVEGRFULL |
653                                           INFINIPATH_E_RRCVHDRFULL |
654                                           INFINIPATH_E_HARDWARE));
655         else
656                 /* so we don't need if (!noprint) at strlcat's below */
657                 *msg = 0;
658
659         if (errs & E_SUM_PKTERRS) {
660                 ipath_stats.sps_pkterrs++;
661                 chkerrpkts = 1;
662         }
663         if (errs & E_SUM_ERRS)
664                 ipath_stats.sps_errs++;
665
666         if (errs & (INFINIPATH_E_RICRC | INFINIPATH_E_RVCRC)) {
667                 ipath_stats.sps_crcerrs++;
668                 chkerrpkts = 1;
669         }
670         iserr = errs & ~(E_SUM_PKTERRS | INFINIPATH_E_PKTERRS);
671
672
673         /*
674          * We don't want to print these two as they happen, or we can make
675          * the situation even worse, because it takes so long to print
676          * messages to serial consoles.  Kernel ports get printed from
677          * fast_stats, no more than every 5 seconds, user ports get printed
678          * on close
679          */
680         if (errs & INFINIPATH_E_RRCVHDRFULL) {
681                 u32 hd, tl;
682                 ipath_stats.sps_hdrqfull++;
683                 for (i = 0; i < dd->ipath_cfgports; i++) {
684                         struct ipath_portdata *pd = dd->ipath_pd[i];
685                         if (i == 0) {
686                                 hd = pd->port_head;
687                                 tl = (u32) le64_to_cpu(
688                                         *dd->ipath_hdrqtailptr);
689                         } else if (pd && pd->port_cnt &&
690                                    pd->port_rcvhdrtail_kvaddr) {
691                                 /*
692                                  * don't report same point multiple times,
693                                  * except kernel
694                                  */
695                                 tl = *(u64 *) pd->port_rcvhdrtail_kvaddr;
696                                 if (tl == pd->port_lastrcvhdrqtail)
697                                         continue;
698                                 hd = ipath_read_ureg32(dd, ur_rcvhdrhead,
699                                                        i);
700                         } else
701                                 continue;
702                         if (hd == (tl + 1) ||
703                             (!hd && tl == dd->ipath_hdrqlast)) {
704                                 if (i == 0)
705                                         chkerrpkts = 1;
706                                 pd->port_lastrcvhdrqtail = tl;
707                                 pd->port_hdrqfull++;
708                                 /* flush hdrqfull so that poll() sees it */
709                                 wmb();
710                                 wake_up_interruptible(&pd->port_wait);
711                         }
712                 }
713         }
714         if (errs & INFINIPATH_E_RRCVEGRFULL) {
715                 struct ipath_portdata *pd = dd->ipath_pd[0];
716
717                 /*
718                  * since this is of less importance and not likely to
719                  * happen without also getting hdrfull, only count
720                  * occurrences; don't check each port (or even the kernel
721                  * vs user)
722                  */
723                 ipath_stats.sps_etidfull++;
724                 if (pd->port_head !=
725                     (u32) le64_to_cpu(*dd->ipath_hdrqtailptr))
726                         chkerrpkts = 1;
727         }
728
729         /*
730          * do this before IBSTATUSCHANGED, in case both bits set in a single
731          * interrupt; we want the STATUSCHANGE to "win", so we do our
732          * internal copy of state machine correctly
733          */
734         if (errs & INFINIPATH_E_RIBLOSTLINK) {
735                 /*
736                  * force through block below
737                  */
738                 errs |= INFINIPATH_E_IBSTATUSCHANGED;
739                 ipath_stats.sps_iblink++;
740                 dd->ipath_flags |= IPATH_LINKDOWN;
741                 dd->ipath_flags &= ~(IPATH_LINKUNK | IPATH_LINKINIT
742                                      | IPATH_LINKARMED | IPATH_LINKACTIVE);
743                 *dd->ipath_statusp &= ~IPATH_STATUS_IB_READY;
744                 if (!noprint) {
745                         u64 st = ipath_read_kreg64(
746                                 dd, dd->ipath_kregs->kr_ibcstatus);
747
748                         ipath_dbg("Lost link, link now down (%s)\n",
749                                   ipath_ibcstatus_str[st & 0xf]);
750                 }
751         }
752         if (errs & INFINIPATH_E_IBSTATUSCHANGED)
753                 handle_e_ibstatuschanged(dd, errs, noprint);
754
755         if (errs & INFINIPATH_E_RESET) {
756                 if (!noprint)
757                         ipath_dev_err(dd, "Got reset, requires re-init "
758                                       "(unload and reload driver)\n");
759                 dd->ipath_flags &= ~IPATH_INITTED;      /* needs re-init */
760                 /* mark as having had error */
761                 *dd->ipath_statusp |= IPATH_STATUS_HWERROR;
762                 *dd->ipath_statusp &= ~IPATH_STATUS_IB_CONF;
763         }
764
765         if (!noprint && *msg) {
766                 if (iserr)
767                         ipath_dev_err(dd, "%s error\n", msg);
768                 else
769                         dev_info(&dd->pcidev->dev, "%s packet problems\n",
770                                 msg);
771         }
772         if (dd->ipath_state_wanted & dd->ipath_flags) {
773                 ipath_cdbg(VERBOSE, "driver wanted state %x, iflags now %x, "
774                            "waking\n", dd->ipath_state_wanted,
775                            dd->ipath_flags);
776                 wake_up_interruptible(&ipath_state_wait);
777         }
778
779         return chkerrpkts;
780 }
781
782
783 /*
784  * try to cleanup as much as possible for anything that might have gone
785  * wrong while in freeze mode, such as pio buffers being written by user
786  * processes (causing armlaunch), send errors due to going into freeze mode,
787  * etc., and try to avoid causing extra interrupts while doing so.
788  * Forcibly update the in-memory pioavail register copies after cleanup
789  * because the chip won't do it for anything changing while in freeze mode
790  * (we don't want to wait for the next pio buffer state change).
791  * Make sure that we don't lose any important interrupts by using the chip
792  * feature that says that writing 0 to a bit in *clear that is set in
793  * *status will cause an interrupt to be generated again (if allowed by
794  * the *mask value).
795  */
796 void ipath_clear_freeze(struct ipath_devdata *dd)
797 {
798         int i, im;
799         __le64 val;
800         unsigned long flags;
801
802         /* disable error interrupts, to avoid confusion */
803         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
804
805         /* also disable interrupts; errormask is sometimes overwriten */
806         ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);
807
808         /*
809          * clear all sends, because they have may been
810          * completed by usercode while in freeze mode, and
811          * therefore would not be sent, and eventually
812          * might cause the process to run out of bufs
813          */
814         ipath_cancel_sends(dd, 0);
815         ipath_write_kreg(dd, dd->ipath_kregs->kr_control,
816                          dd->ipath_control);
817
818         /* ensure pio avail updates continue */
819         spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
820         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
821                  dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);
822         ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
823         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
824                          dd->ipath_sendctrl);
825         ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
826         spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
827
828         /*
829          * We just enabled pioavailupdate, so dma copy is almost certainly
830          * not yet right, so read the registers directly.  Similar to init
831          */
832         for (i = 0; i < dd->ipath_pioavregs; i++) {
833                 /* deal with 6110 chip bug */
834                 im = i > 3 ? i ^ 1 : i;
835                 val = ipath_read_kreg64(dd, (0x1000 / sizeof(u64)) + im);
836                 dd->ipath_pioavailregs_dma[i] = dd->ipath_pioavailshadow[i]
837                         = le64_to_cpu(val);
838         }
839
840         /*
841          * force new interrupt if any hwerr, error or interrupt bits are
842          * still set, and clear "safe" send packet errors related to freeze
843          * and cancelling sends.  Re-enable error interrupts before possible
844          * force of re-interrupt on pending interrupts.
845          */
846         ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear, 0ULL);
847         ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear,
848                 E_SPKT_ERRS_IGNORE);
849         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
850                 dd->ipath_errormask);
851         ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, -1LL);
852         ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, 0ULL);
853 }
854
855
856 /* this is separate to allow for better optimization of ipath_intr() */
857
858 static noinline void ipath_bad_intr(struct ipath_devdata *dd, u32 *unexpectp)
859 {
860         /*
861          * sometimes happen during driver init and unload, don't want
862          * to process any interrupts at that point
863          */
864
865         /* this is just a bandaid, not a fix, if something goes badly
866          * wrong */
867         if (++*unexpectp > 100) {
868                 if (++*unexpectp > 105) {
869                         /*
870                          * ok, we must be taking somebody else's interrupts,
871                          * due to a messed up mptable and/or PIRQ table, so
872                          * unregister the interrupt.  We've seen this during
873                          * linuxbios development work, and it may happen in
874                          * the future again.
875                          */
876                         if (dd->pcidev && dd->ipath_irq) {
877                                 ipath_dev_err(dd, "Now %u unexpected "
878                                               "interrupts, unregistering "
879                                               "interrupt handler\n",
880                                               *unexpectp);
881                                 ipath_dbg("free_irq of irq %d\n",
882                                           dd->ipath_irq);
883                                 dd->ipath_f_free_irq(dd);
884                         }
885                 }
886                 if (ipath_read_ireg(dd, dd->ipath_kregs->kr_intmask)) {
887                         ipath_dev_err(dd, "%u unexpected interrupts, "
888                                       "disabling interrupts completely\n",
889                                       *unexpectp);
890                         /*
891                          * disable all interrupts, something is very wrong
892                          */
893                         ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask,
894                                          0ULL);
895                 }
896         } else if (*unexpectp > 1)
897                 ipath_dbg("Interrupt when not ready, should not happen, "
898                           "ignoring\n");
899 }
900
901 static noinline void ipath_bad_regread(struct ipath_devdata *dd)
902 {
903         static int allbits;
904
905         /* separate routine, for better optimization of ipath_intr() */
906
907         /*
908          * We print the message and disable interrupts, in hope of
909          * having a better chance of debugging the problem.
910          */
911         ipath_dev_err(dd,
912                       "Read of interrupt status failed (all bits set)\n");
913         if (allbits++) {
914                 /* disable all interrupts, something is very wrong */
915                 ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);
916                 if (allbits == 2) {
917                         ipath_dev_err(dd, "Still bad interrupt status, "
918                                       "unregistering interrupt\n");
919                         dd->ipath_f_free_irq(dd);
920                 } else if (allbits > 2) {
921                         if ((allbits % 10000) == 0)
922                                 printk(".");
923                 } else
924                         ipath_dev_err(dd, "Disabling interrupts, "
925                                       "multiple errors\n");
926         }
927 }
928
929 static void handle_layer_pioavail(struct ipath_devdata *dd)
930 {
931         unsigned long flags;
932         int ret;
933
934         ret = ipath_ib_piobufavail(dd->verbs_dev);
935         if (ret > 0)
936                 goto set;
937
938         return;
939 set:
940         spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
941         dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
942         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
943                          dd->ipath_sendctrl);
944         ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
945         spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
946 }
947
948 /*
949  * Handle receive interrupts for user ports; this means a user
950  * process was waiting for a packet to arrive, and didn't want
951  * to poll
952  */
953 static void handle_urcv(struct ipath_devdata *dd, u32 istat)
954 {
955         u64 portr;
956         int i;
957         int rcvdint = 0;
958
959         /*
960          * test_and_clear_bit(IPATH_PORT_WAITING_RCV) and
961          * test_and_clear_bit(IPATH_PORT_WAITING_URG) below
962          * would both like timely updates of the bits so that
963          * we don't pass them by unnecessarily.  the rmb()
964          * here ensures that we see them promptly -- the
965          * corresponding wmb()'s are in ipath_poll_urgent()
966          * and ipath_poll_next()...
967          */
968         rmb();
969         portr = ((istat >> INFINIPATH_I_RCVAVAIL_SHIFT) &
970                  dd->ipath_i_rcvavail_mask)
971                 | ((istat >> INFINIPATH_I_RCVURG_SHIFT) &
972                    dd->ipath_i_rcvurg_mask);
973         for (i = 1; i < dd->ipath_cfgports; i++) {
974                 struct ipath_portdata *pd = dd->ipath_pd[i];
975                 if (portr & (1 << i) && pd && pd->port_cnt) {
976                         if (test_and_clear_bit(IPATH_PORT_WAITING_RCV,
977                                                &pd->port_flag)) {
978                                 clear_bit(i + dd->ipath_r_intravail_shift,
979                                           &dd->ipath_rcvctrl);
980                                 wake_up_interruptible(&pd->port_wait);
981                                 rcvdint = 1;
982                         } else if (test_and_clear_bit(IPATH_PORT_WAITING_URG,
983                                                       &pd->port_flag)) {
984                                 pd->port_urgent++;
985                                 wake_up_interruptible(&pd->port_wait);
986                         }
987                 }
988         }
989         if (rcvdint) {
990                 /* only want to take one interrupt, so turn off the rcv
991                  * interrupt for all the ports that we did the wakeup on
992                  * (but never for kernel port)
993                  */
994                 ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
995                                  dd->ipath_rcvctrl);
996         }
997 }
998
999 irqreturn_t ipath_intr(int irq, void *data)
1000 {
1001         struct ipath_devdata *dd = data;
1002         u32 istat, chk0rcv = 0;
1003         ipath_err_t estat = 0;
1004         irqreturn_t ret;
1005         static unsigned unexpected = 0;
1006         static const u32 port0rbits = (1U<<INFINIPATH_I_RCVAVAIL_SHIFT) |
1007                  (1U<<INFINIPATH_I_RCVURG_SHIFT);
1008
1009         ipath_stats.sps_ints++;
1010
1011         if (dd->ipath_int_counter != (u32) -1)
1012                 dd->ipath_int_counter++;
1013
1014         if (!(dd->ipath_flags & IPATH_PRESENT)) {
1015                 /*
1016                  * This return value is not great, but we do not want the
1017                  * interrupt core code to remove our interrupt handler
1018                  * because we don't appear to be handling an interrupt
1019                  * during a chip reset.
1020                  */
1021                 return IRQ_HANDLED;
1022         }
1023
1024         /*
1025          * this needs to be flags&initted, not statusp, so we keep
1026          * taking interrupts even after link goes down, etc.
1027          * Also, we *must* clear the interrupt at some point, or we won't
1028          * take it again, which can be real bad for errors, etc...
1029          */
1030
1031         if (!(dd->ipath_flags & IPATH_INITTED)) {
1032                 ipath_bad_intr(dd, &unexpected);
1033                 ret = IRQ_NONE;
1034                 goto bail;
1035         }
1036
1037         istat = ipath_read_ireg(dd, dd->ipath_kregs->kr_intstatus);
1038
1039         if (unlikely(!istat)) {
1040                 ipath_stats.sps_nullintr++;
1041                 ret = IRQ_NONE; /* not our interrupt, or already handled */
1042                 goto bail;
1043         }
1044         if (unlikely(istat == -1)) {
1045                 ipath_bad_regread(dd);
1046                 /* don't know if it was our interrupt or not */
1047                 ret = IRQ_NONE;
1048                 goto bail;
1049         }
1050
1051         if (unexpected)
1052                 unexpected = 0;
1053
1054         if (unlikely(istat & ~dd->ipath_i_bitsextant))
1055                 ipath_dev_err(dd,
1056                               "interrupt with unknown interrupts %x set\n",
1057                               istat & (u32) ~ dd->ipath_i_bitsextant);
1058         else
1059                 ipath_cdbg(VERBOSE, "intr stat=0x%x\n", istat);
1060
1061         if (unlikely(istat & INFINIPATH_I_ERROR)) {
1062                 ipath_stats.sps_errints++;
1063                 estat = ipath_read_kreg64(dd,
1064                                           dd->ipath_kregs->kr_errorstatus);
1065                 if (!estat)
1066                         dev_info(&dd->pcidev->dev, "error interrupt (%x), "
1067                                  "but no error bits set!\n", istat);
1068                 else if (estat == -1LL)
1069                         /*
1070                          * should we try clearing all, or hope next read
1071                          * works?
1072                          */
1073                         ipath_dev_err(dd, "Read of error status failed "
1074                                       "(all bits set); ignoring\n");
1075                 else
1076                         if (handle_errors(dd, estat))
1077                                 /* force calling ipath_kreceive() */
1078                                 chk0rcv = 1;
1079         }
1080
1081         if (istat & INFINIPATH_I_GPIO) {
1082                 /*
1083                  * GPIO interrupts fall in two broad classes:
1084                  * GPIO_2 indicates (on some HT4xx boards) that a packet
1085                  *        has arrived for Port 0. Checking for this
1086                  *        is controlled by flag IPATH_GPIO_INTR.
1087                  * GPIO_3..5 on IBA6120 Rev2 and IBA6110 Rev4 chips indicate
1088                  *        errors that we need to count. Checking for this
1089                  *        is controlled by flag IPATH_GPIO_ERRINTRS.
1090                  */
1091                 u32 gpiostatus;
1092                 u32 to_clear = 0;
1093
1094                 gpiostatus = ipath_read_kreg32(
1095                         dd, dd->ipath_kregs->kr_gpio_status);
1096                 /* First the error-counter case.
1097                  */
1098                 if ((gpiostatus & IPATH_GPIO_ERRINTR_MASK) &&
1099                     (dd->ipath_flags & IPATH_GPIO_ERRINTRS)) {
1100                         /* want to clear the bits we see asserted. */
1101                         to_clear |= (gpiostatus & IPATH_GPIO_ERRINTR_MASK);
1102
1103                         /*
1104                          * Count appropriately, clear bits out of our copy,
1105                          * as they have been "handled".
1106                          */
1107                         if (gpiostatus & (1 << IPATH_GPIO_RXUVL_BIT)) {
1108                                 ipath_dbg("FlowCtl on UnsupVL\n");
1109                                 dd->ipath_rxfc_unsupvl_errs++;
1110                         }
1111                         if (gpiostatus & (1 << IPATH_GPIO_OVRUN_BIT)) {
1112                                 ipath_dbg("Overrun Threshold exceeded\n");
1113                                 dd->ipath_overrun_thresh_errs++;
1114                         }
1115                         if (gpiostatus & (1 << IPATH_GPIO_LLI_BIT)) {
1116                                 ipath_dbg("Local Link Integrity error\n");
1117                                 dd->ipath_lli_errs++;
1118                         }
1119                         gpiostatus &= ~IPATH_GPIO_ERRINTR_MASK;
1120                 }
1121                 /* Now the Port0 Receive case */
1122                 if ((gpiostatus & (1 << IPATH_GPIO_PORT0_BIT)) &&
1123                     (dd->ipath_flags & IPATH_GPIO_INTR)) {
1124                         /*
1125                          * GPIO status bit 2 is set, and we expected it.
1126                          * clear it and indicate in p0bits.
1127                          * This probably only happens if a Port0 pkt
1128                          * arrives at _just_ the wrong time, and we
1129                          * handle that by seting chk0rcv;
1130                          */
1131                         to_clear |= (1 << IPATH_GPIO_PORT0_BIT);
1132                         gpiostatus &= ~(1 << IPATH_GPIO_PORT0_BIT);
1133                         chk0rcv = 1;
1134                 }
1135                 if (gpiostatus) {
1136                         /*
1137                          * Some unexpected bits remain. If they could have
1138                          * caused the interrupt, complain and clear.
1139                          * To avoid repetition of this condition, also clear
1140                          * the mask. It is almost certainly due to error.
1141                          */
1142                         const u32 mask = (u32) dd->ipath_gpio_mask;
1143
1144                         if (mask & gpiostatus) {
1145                                 ipath_dbg("Unexpected GPIO IRQ bits %x\n",
1146                                   gpiostatus & mask);
1147                                 to_clear |= (gpiostatus & mask);
1148                                 dd->ipath_gpio_mask &= ~(gpiostatus & mask);
1149                                 ipath_write_kreg(dd,
1150                                         dd->ipath_kregs->kr_gpio_mask,
1151                                         dd->ipath_gpio_mask);
1152                         }
1153                 }
1154                 if (to_clear) {
1155                         ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_clear,
1156                                         (u64) to_clear);
1157                 }
1158         }
1159         chk0rcv |= istat & port0rbits;
1160
1161         /*
1162          * Clear the interrupt bits we found set, unless they are receive
1163          * related, in which case we already cleared them above, and don't
1164          * want to clear them again, because we might lose an interrupt.
1165          * Clear it early, so we "know" know the chip will have seen this by
1166          * the time we process the queue, and will re-interrupt if necessary.
1167          * The processor itself won't take the interrupt again until we return.
1168          */
1169         ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, istat);
1170
1171         /*
1172          * handle port0 receive  before checking for pio buffers available,
1173          * since receives can overflow; piobuf waiters can afford a few
1174          * extra cycles, since they were waiting anyway, and user's waiting
1175          * for receive are at the bottom.
1176          */
1177         if (chk0rcv) {
1178                 ipath_kreceive(dd->ipath_pd[0]);
1179                 istat &= ~port0rbits;
1180         }
1181
1182         if (istat & ((dd->ipath_i_rcvavail_mask <<
1183                       INFINIPATH_I_RCVAVAIL_SHIFT)
1184                      | (dd->ipath_i_rcvurg_mask <<
1185                         INFINIPATH_I_RCVURG_SHIFT)))
1186                 handle_urcv(dd, istat);
1187
1188         if (istat & INFINIPATH_I_SPIOBUFAVAIL) {
1189                 unsigned long flags;
1190
1191                 spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
1192                 dd->ipath_sendctrl &= ~INFINIPATH_S_PIOINTBUFAVAIL;
1193                 ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
1194                                  dd->ipath_sendctrl);
1195                 ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
1196                 spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
1197
1198                 handle_layer_pioavail(dd);
1199         }
1200
1201         ret = IRQ_HANDLED;
1202
1203 bail:
1204         return ret;
1205 }