Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / hw / ipath / ipath_intr.c
diff --git a/kernel/drivers/infiniband/hw/ipath/ipath_intr.c b/kernel/drivers/infiniband/hw/ipath/ipath_intr.c
new file mode 100644 (file)
index 0000000..01ba792
--- /dev/null
@@ -0,0 +1,1273 @@
+/*
+ * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
+ * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+
+#include "ipath_kernel.h"
+#include "ipath_verbs.h"
+#include "ipath_common.h"
+
+
+/*
+ * Called when we might have an error that is specific to a particular
+ * PIO buffer, and may need to cancel that buffer, so it can be re-used.
+ */
+void ipath_disarm_senderrbufs(struct ipath_devdata *dd)
+{
+       u32 piobcnt;
+       unsigned long sbuf[4];
+       /*
+        * it's possible that sendbuffererror could have bits set; might
+        * have already done this as a result of hardware error handling
+        */
+       piobcnt = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
+       /* read these before writing errorclear */
+       sbuf[0] = ipath_read_kreg64(
+               dd, dd->ipath_kregs->kr_sendbuffererror);
+       sbuf[1] = ipath_read_kreg64(
+               dd, dd->ipath_kregs->kr_sendbuffererror + 1);
+       if (piobcnt > 128)
+               sbuf[2] = ipath_read_kreg64(
+                       dd, dd->ipath_kregs->kr_sendbuffererror + 2);
+       if (piobcnt > 192)
+               sbuf[3] = ipath_read_kreg64(
+                       dd, dd->ipath_kregs->kr_sendbuffererror + 3);
+       else
+               sbuf[3] = 0;
+
+       if (sbuf[0] || sbuf[1] || (piobcnt > 128 && (sbuf[2] || sbuf[3]))) {
+               int i;
+               if (ipath_debug & (__IPATH_PKTDBG|__IPATH_DBG) &&
+                       time_after(dd->ipath_lastcancel, jiffies)) {
+                       __IPATH_DBG_WHICH(__IPATH_PKTDBG|__IPATH_DBG,
+                                         "SendbufErrs %lx %lx", sbuf[0],
+                                         sbuf[1]);
+                       if (ipath_debug & __IPATH_PKTDBG && piobcnt > 128)
+                               printk(" %lx %lx ", sbuf[2], sbuf[3]);
+                       printk("\n");
+               }
+
+               for (i = 0; i < piobcnt; i++)
+                       if (test_bit(i, sbuf))
+                               ipath_disarm_piobufs(dd, i, 1);
+               /* ignore armlaunch errs for a bit */
+               dd->ipath_lastcancel = jiffies+3;
+       }
+}
+
+
+/* These are all rcv-related errors which we want to count for stats */
+#define E_SUM_PKTERRS \
+       (INFINIPATH_E_RHDRLEN | INFINIPATH_E_RBADTID | \
+        INFINIPATH_E_RBADVERSION | INFINIPATH_E_RHDR | \
+        INFINIPATH_E_RLONGPKTLEN | INFINIPATH_E_RSHORTPKTLEN | \
+        INFINIPATH_E_RMAXPKTLEN | INFINIPATH_E_RMINPKTLEN | \
+        INFINIPATH_E_RFORMATERR | INFINIPATH_E_RUNSUPVL | \
+        INFINIPATH_E_RUNEXPCHAR | INFINIPATH_E_REBP)
+
+/* These are all send-related errors which we want to count for stats */
+#define E_SUM_ERRS \
+       (INFINIPATH_E_SPIOARMLAUNCH | INFINIPATH_E_SUNEXPERRPKTNUM | \
+        INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
+        INFINIPATH_E_SMAXPKTLEN | INFINIPATH_E_SUNSUPVL | \
+        INFINIPATH_E_SMINPKTLEN | INFINIPATH_E_SPKTLEN | \
+        INFINIPATH_E_INVALIDADDR)
+
+/*
+ * this is similar to E_SUM_ERRS, but can't ignore armlaunch, don't ignore
+ * errors not related to freeze and cancelling buffers.  Can't ignore
+ * armlaunch because could get more while still cleaning up, and need
+ * to cancel those as they happen.
+ */
+#define E_SPKT_ERRS_IGNORE \
+        (INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
+        INFINIPATH_E_SMAXPKTLEN | INFINIPATH_E_SMINPKTLEN | \
+        INFINIPATH_E_SPKTLEN)
+
+/*
+ * these are errors that can occur when the link changes state while
+ * a packet is being sent or received.  This doesn't cover things
+ * like EBP or VCRC that can be the result of a sending having the
+ * link change state, so we receive a "known bad" packet.
+ */
+#define E_SUM_LINK_PKTERRS \
+       (INFINIPATH_E_SDROPPEDDATAPKT | INFINIPATH_E_SDROPPEDSMPPKT | \
+        INFINIPATH_E_SMINPKTLEN | INFINIPATH_E_SPKTLEN | \
+        INFINIPATH_E_RSHORTPKTLEN | INFINIPATH_E_RMINPKTLEN | \
+        INFINIPATH_E_RUNEXPCHAR)
+
+static u64 handle_e_sum_errs(struct ipath_devdata *dd, ipath_err_t errs)
+{
+       u64 ignore_this_time = 0;
+
+       ipath_disarm_senderrbufs(dd);
+       if ((errs & E_SUM_LINK_PKTERRS) &&
+           !(dd->ipath_flags & IPATH_LINKACTIVE)) {
+               /*
+                * This can happen when SMA is trying to bring the link
+                * up, but the IB link changes state at the "wrong" time.
+                * The IB logic then complains that the packet isn't
+                * valid.  We don't want to confuse people, so we just
+                * don't print them, except at debug
+                */
+               ipath_dbg("Ignoring packet errors %llx, because link not "
+                         "ACTIVE\n", (unsigned long long) errs);
+               ignore_this_time = errs & E_SUM_LINK_PKTERRS;
+       }
+
+       return ignore_this_time;
+}
+
+/* generic hw error messages... */
+#define INFINIPATH_HWE_TXEMEMPARITYERR_MSG(a) \
+       { \
+               .mask = ( INFINIPATH_HWE_TXEMEMPARITYERR_##a <<    \
+                         INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT ),   \
+               .msg = "TXE " #a " Memory Parity"            \
+       }
+#define INFINIPATH_HWE_RXEMEMPARITYERR_MSG(a) \
+       { \
+               .mask = ( INFINIPATH_HWE_RXEMEMPARITYERR_##a <<    \
+                         INFINIPATH_HWE_RXEMEMPARITYERR_SHIFT ),   \
+               .msg = "RXE " #a " Memory Parity"            \
+       }
+
+static const struct ipath_hwerror_msgs ipath_generic_hwerror_msgs[] = {
+       INFINIPATH_HWE_MSG(IBCBUSFRSPCPARITYERR, "IPATH2IB Parity"),
+       INFINIPATH_HWE_MSG(IBCBUSTOSPCPARITYERR, "IB2IPATH Parity"),
+
+       INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOBUF),
+       INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOPBC),
+       INFINIPATH_HWE_TXEMEMPARITYERR_MSG(PIOLAUNCHFIFO),
+
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(RCVBUF),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(LOOKUPQ),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(EAGERTID),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(EXPTID),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(FLAGBUF),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(DATAINFO),
+       INFINIPATH_HWE_RXEMEMPARITYERR_MSG(HDRINFO),
+};
+
+/**
+ * ipath_format_hwmsg - format a single hwerror message
+ * @msg message buffer
+ * @msgl length of message buffer
+ * @hwmsg message to add to message buffer
+ */
+static void ipath_format_hwmsg(char *msg, size_t msgl, const char *hwmsg)
+{
+       strlcat(msg, "[", msgl);
+       strlcat(msg, hwmsg, msgl);
+       strlcat(msg, "]", msgl);
+}
+
+/**
+ * ipath_format_hwerrors - format hardware error messages for display
+ * @hwerrs hardware errors bit vector
+ * @hwerrmsgs hardware error descriptions
+ * @nhwerrmsgs number of hwerrmsgs
+ * @msg message buffer
+ * @msgl message buffer length
+ */
+void ipath_format_hwerrors(u64 hwerrs,
+                          const struct ipath_hwerror_msgs *hwerrmsgs,
+                          size_t nhwerrmsgs,
+                          char *msg, size_t msgl)
+{
+       int i;
+       const int glen =
+           ARRAY_SIZE(ipath_generic_hwerror_msgs);
+
+       for (i=0; i<glen; i++) {
+               if (hwerrs & ipath_generic_hwerror_msgs[i].mask) {
+                       ipath_format_hwmsg(msg, msgl,
+                                          ipath_generic_hwerror_msgs[i].msg);
+               }
+       }
+
+       for (i=0; i<nhwerrmsgs; i++) {
+               if (hwerrs & hwerrmsgs[i].mask) {
+                       ipath_format_hwmsg(msg, msgl, hwerrmsgs[i].msg);
+               }
+       }
+}
+
+/* return the strings for the most common link states */
+static char *ib_linkstate(struct ipath_devdata *dd, u64 ibcs)
+{
+       char *ret;
+       u32 state;
+
+       state = ipath_ib_state(dd, ibcs);
+       if (state == dd->ib_init)
+               ret = "Init";
+       else if (state == dd->ib_arm)
+               ret = "Arm";
+       else if (state == dd->ib_active)
+               ret = "Active";
+       else
+               ret = "Down";
+       return ret;
+}
+
+void signal_ib_event(struct ipath_devdata *dd, enum ib_event_type ev)
+{
+       struct ib_event event;
+
+       event.device = &dd->verbs_dev->ibdev;
+       event.element.port_num = 1;
+       event.event = ev;
+       ib_dispatch_event(&event);
+}
+
+static void handle_e_ibstatuschanged(struct ipath_devdata *dd,
+                                    ipath_err_t errs)
+{
+       u32 ltstate, lstate, ibstate, lastlstate;
+       u32 init = dd->ib_init;
+       u32 arm = dd->ib_arm;
+       u32 active = dd->ib_active;
+       const u64 ibcs = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
+
+       lstate = ipath_ib_linkstate(dd, ibcs); /* linkstate */
+       ibstate = ipath_ib_state(dd, ibcs);
+       /* linkstate at last interrupt */
+       lastlstate = ipath_ib_linkstate(dd, dd->ipath_lastibcstat);
+       ltstate = ipath_ib_linktrstate(dd, ibcs); /* linktrainingtate */
+
+       /*
+        * Since going into a recovery state causes the link state to go
+        * down and since recovery is transitory, it is better if we "miss"
+        * ever seeing the link training state go into recovery (i.e.,
+        * ignore this transition for link state special handling purposes)
+        * without even updating ipath_lastibcstat.
+        */
+       if ((ltstate == INFINIPATH_IBCS_LT_STATE_RECOVERRETRAIN) ||
+           (ltstate == INFINIPATH_IBCS_LT_STATE_RECOVERWAITRMT) ||
+           (ltstate == INFINIPATH_IBCS_LT_STATE_RECOVERIDLE))
+               goto done;
+
+       /*
+        * if linkstate transitions into INIT from any of the various down
+        * states, or if it transitions from any of the up (INIT or better)
+        * states into any of the down states (except link recovery), then
+        * call the chip-specific code to take appropriate actions.
+        */
+       if (lstate >= INFINIPATH_IBCS_L_STATE_INIT &&
+               lastlstate == INFINIPATH_IBCS_L_STATE_DOWN) {
+               /* transitioned to UP */
+               if (dd->ipath_f_ib_updown(dd, 1, ibcs)) {
+                       /* link came up, so we must no longer be disabled */
+                       dd->ipath_flags &= ~IPATH_IB_LINK_DISABLED;
+                       ipath_cdbg(LINKVERB, "LinkUp handled, skipped\n");
+                       goto skip_ibchange; /* chip-code handled */
+               }
+       } else if ((lastlstate >= INFINIPATH_IBCS_L_STATE_INIT ||
+               (dd->ipath_flags & IPATH_IB_FORCE_NOTIFY)) &&
+               ltstate <= INFINIPATH_IBCS_LT_STATE_CFGWAITRMT &&
+               ltstate != INFINIPATH_IBCS_LT_STATE_LINKUP) {
+               int handled;
+               handled = dd->ipath_f_ib_updown(dd, 0, ibcs);
+               dd->ipath_flags &= ~IPATH_IB_FORCE_NOTIFY;
+               if (handled) {
+                       ipath_cdbg(LINKVERB, "LinkDown handled, skipped\n");
+                       goto skip_ibchange; /* chip-code handled */
+               }
+       }
+
+       /*
+        * Significant enough to always print and get into logs, if it was
+        * unexpected.  If it was a requested state change, we'll have
+        * already cleared the flags, so we won't print this warning
+        */
+       if ((ibstate != arm && ibstate != active) &&
+           (dd->ipath_flags & (IPATH_LINKARMED | IPATH_LINKACTIVE))) {
+               dev_info(&dd->pcidev->dev, "Link state changed from %s "
+                        "to %s\n", (dd->ipath_flags & IPATH_LINKARMED) ?
+                        "ARM" : "ACTIVE", ib_linkstate(dd, ibcs));
+       }
+
+       if (ltstate == INFINIPATH_IBCS_LT_STATE_POLLACTIVE ||
+           ltstate == INFINIPATH_IBCS_LT_STATE_POLLQUIET) {
+               u32 lastlts;
+               lastlts = ipath_ib_linktrstate(dd, dd->ipath_lastibcstat);
+               /*
+                * Ignore cycling back and forth from Polling.Active to
+                * Polling.Quiet while waiting for the other end of the link
+                * to come up, except to try and decide if we are connected
+                * to a live IB device or not.  We will cycle back and
+                * forth between them if no cable is plugged in, the other
+                * device is powered off or disabled, etc.
+                */
+               if (lastlts == INFINIPATH_IBCS_LT_STATE_POLLACTIVE ||
+                   lastlts == INFINIPATH_IBCS_LT_STATE_POLLQUIET) {
+                       if (!(dd->ipath_flags & IPATH_IB_AUTONEG_INPROG) &&
+                            (++dd->ipath_ibpollcnt == 40)) {
+                               dd->ipath_flags |= IPATH_NOCABLE;
+                               *dd->ipath_statusp |=
+                                       IPATH_STATUS_IB_NOCABLE;
+                               ipath_cdbg(LINKVERB, "Set NOCABLE\n");
+                       }
+                       ipath_cdbg(LINKVERB, "POLL change to %s (%x)\n",
+                               ipath_ibcstatus_str[ltstate], ibstate);
+                       goto skip_ibchange;
+               }
+       }
+
+       dd->ipath_ibpollcnt = 0; /* not poll*, now */
+       ipath_stats.sps_iblink++;
+
+       if (ibstate != init && dd->ipath_lastlinkrecov && ipath_linkrecovery) {
+               u64 linkrecov;
+               linkrecov = ipath_snap_cntr(dd,
+                       dd->ipath_cregs->cr_iblinkerrrecovcnt);
+               if (linkrecov != dd->ipath_lastlinkrecov) {
+                       ipath_dbg("IB linkrecov up %Lx (%s %s) recov %Lu\n",
+                               (unsigned long long) ibcs,
+                               ib_linkstate(dd, ibcs),
+                               ipath_ibcstatus_str[ltstate],
+                               (unsigned long long) linkrecov);
+                       /* and no more until active again */
+                       dd->ipath_lastlinkrecov = 0;
+                       ipath_set_linkstate(dd, IPATH_IB_LINKDOWN);
+                       goto skip_ibchange;
+               }
+       }
+
+       if (ibstate == init || ibstate == arm || ibstate == active) {
+               *dd->ipath_statusp &= ~IPATH_STATUS_IB_NOCABLE;
+               if (ibstate == init || ibstate == arm) {
+                       *dd->ipath_statusp &= ~IPATH_STATUS_IB_READY;
+                       if (dd->ipath_flags & IPATH_LINKACTIVE)
+                               signal_ib_event(dd, IB_EVENT_PORT_ERR);
+               }
+               if (ibstate == arm) {
+                       dd->ipath_flags |= IPATH_LINKARMED;
+                       dd->ipath_flags &= ~(IPATH_LINKUNK |
+                               IPATH_LINKINIT | IPATH_LINKDOWN |
+                               IPATH_LINKACTIVE | IPATH_NOCABLE);
+                       ipath_hol_down(dd);
+               } else  if (ibstate == init) {
+                       /*
+                        * set INIT and DOWN.  Down is checked by
+                        * most of the other code, but INIT is
+                        * useful to know in a few places.
+                        */
+                       dd->ipath_flags |= IPATH_LINKINIT |
+                               IPATH_LINKDOWN;
+                       dd->ipath_flags &= ~(IPATH_LINKUNK |
+                               IPATH_LINKARMED | IPATH_LINKACTIVE |
+                               IPATH_NOCABLE);
+                       ipath_hol_down(dd);
+               } else {  /* active */
+                       dd->ipath_lastlinkrecov = ipath_snap_cntr(dd,
+                               dd->ipath_cregs->cr_iblinkerrrecovcnt);
+                       *dd->ipath_statusp |=
+                               IPATH_STATUS_IB_READY | IPATH_STATUS_IB_CONF;
+                       dd->ipath_flags |= IPATH_LINKACTIVE;
+                       dd->ipath_flags &= ~(IPATH_LINKUNK | IPATH_LINKINIT
+                               | IPATH_LINKDOWN | IPATH_LINKARMED |
+                               IPATH_NOCABLE);
+                       if (dd->ipath_flags & IPATH_HAS_SEND_DMA)
+                               ipath_restart_sdma(dd);
+                       signal_ib_event(dd, IB_EVENT_PORT_ACTIVE);
+                       /* LED active not handled in chip _f_updown */
+                       dd->ipath_f_setextled(dd, lstate, ltstate);
+                       ipath_hol_up(dd);
+               }
+
+               /*
+                * print after we've already done the work, so as not to
+                * delay the state changes and notifications, for debugging
+                */
+               if (lstate == lastlstate)
+                       ipath_cdbg(LINKVERB, "Unchanged from last: %s "
+                               "(%x)\n", ib_linkstate(dd, ibcs), ibstate);
+               else
+                       ipath_cdbg(VERBOSE, "Unit %u: link up to %s %s (%x)\n",
+                                 dd->ipath_unit, ib_linkstate(dd, ibcs),
+                                 ipath_ibcstatus_str[ltstate],  ibstate);
+       } else { /* down */
+               if (dd->ipath_flags & IPATH_LINKACTIVE)
+                       signal_ib_event(dd, IB_EVENT_PORT_ERR);
+               dd->ipath_flags |= IPATH_LINKDOWN;
+               dd->ipath_flags &= ~(IPATH_LINKUNK | IPATH_LINKINIT
+                                    | IPATH_LINKACTIVE |
+                                    IPATH_LINKARMED);
+               *dd->ipath_statusp &= ~IPATH_STATUS_IB_READY;
+               dd->ipath_lli_counter = 0;
+
+               if (lastlstate != INFINIPATH_IBCS_L_STATE_DOWN)
+                       ipath_cdbg(VERBOSE, "Unit %u link state down "
+                                  "(state 0x%x), from %s\n",
+                                  dd->ipath_unit, lstate,
+                                  ib_linkstate(dd, dd->ipath_lastibcstat));
+               else
+                       ipath_cdbg(LINKVERB, "Unit %u link state changed "
+                                  "to %s (0x%x) from down (%x)\n",
+                                  dd->ipath_unit,
+                                  ipath_ibcstatus_str[ltstate],
+                                  ibstate, lastlstate);
+       }
+
+skip_ibchange:
+       dd->ipath_lastibcstat = ibcs;
+done:
+       return;
+}
+
+static void handle_supp_msgs(struct ipath_devdata *dd,
+                            unsigned supp_msgs, char *msg, u32 msgsz)
+{
+       /*
+        * Print the message unless it's ibc status change only, which
+        * happens so often we never want to count it.
+        */
+       if (dd->ipath_lasterror & ~INFINIPATH_E_IBSTATUSCHANGED) {
+               int iserr;
+               ipath_err_t mask;
+               iserr = ipath_decode_err(dd, msg, msgsz,
+                                        dd->ipath_lasterror &
+                                        ~INFINIPATH_E_IBSTATUSCHANGED);
+
+               mask = INFINIPATH_E_RRCVEGRFULL | INFINIPATH_E_RRCVHDRFULL |
+                       INFINIPATH_E_PKTERRS | INFINIPATH_E_SDMADISABLED;
+
+               /* if we're in debug, then don't mask SDMADISABLED msgs */
+               if (ipath_debug & __IPATH_DBG)
+                       mask &= ~INFINIPATH_E_SDMADISABLED;
+
+               if (dd->ipath_lasterror & ~mask)
+                       ipath_dev_err(dd, "Suppressed %u messages for "
+                                     "fast-repeating errors (%s) (%llx)\n",
+                                     supp_msgs, msg,
+                                     (unsigned long long)
+                                     dd->ipath_lasterror);
+               else {
+                       /*
+                        * rcvegrfull and rcvhdrqfull are "normal", for some
+                        * types of processes (mostly benchmarks) that send
+                        * huge numbers of messages, while not processing
+                        * them. So only complain about these at debug
+                        * level.
+                        */
+                       if (iserr)
+                               ipath_dbg("Suppressed %u messages for %s\n",
+                                         supp_msgs, msg);
+                       else
+                               ipath_cdbg(ERRPKT,
+                                       "Suppressed %u messages for %s\n",
+                                         supp_msgs, msg);
+               }
+       }
+}
+
+static unsigned handle_frequent_errors(struct ipath_devdata *dd,
+                                      ipath_err_t errs, char *msg,
+                                      u32 msgsz, int *noprint)
+{
+       unsigned long nc;
+       static unsigned long nextmsg_time;
+       static unsigned nmsgs, supp_msgs;
+
+       /*
+        * Throttle back "fast" messages to no more than 10 per 5 seconds.
+        * This isn't perfect, but it's a reasonable heuristic. If we get
+        * more than 10, give a 6x longer delay.
+        */
+       nc = jiffies;
+       if (nmsgs > 10) {
+               if (time_before(nc, nextmsg_time)) {
+                       *noprint = 1;
+                       if (!supp_msgs++)
+                               nextmsg_time = nc + HZ * 3;
+               }
+               else if (supp_msgs) {
+                       handle_supp_msgs(dd, supp_msgs, msg, msgsz);
+                       supp_msgs = 0;
+                       nmsgs = 0;
+               }
+       }
+       else if (!nmsgs++ || time_after(nc, nextmsg_time))
+               nextmsg_time = nc + HZ / 2;
+
+       return supp_msgs;
+}
+
+static void handle_sdma_errors(struct ipath_devdata *dd, ipath_err_t errs)
+{
+       unsigned long flags;
+       int expected;
+
+       if (ipath_debug & __IPATH_DBG) {
+               char msg[128];
+               ipath_decode_err(dd, msg, sizeof msg, errs &
+                       INFINIPATH_E_SDMAERRS);
+               ipath_dbg("errors %lx (%s)\n", (unsigned long)errs, msg);
+       }
+       if (ipath_debug & __IPATH_VERBDBG) {
+               unsigned long tl, hd, status, lengen;
+               tl = ipath_read_kreg64(dd, dd->ipath_kregs->kr_senddmatail);
+               hd = ipath_read_kreg64(dd, dd->ipath_kregs->kr_senddmahead);
+               status = ipath_read_kreg64(dd
+                       , dd->ipath_kregs->kr_senddmastatus);
+               lengen = ipath_read_kreg64(dd,
+                       dd->ipath_kregs->kr_senddmalengen);
+               ipath_cdbg(VERBOSE, "sdma tl 0x%lx hd 0x%lx status 0x%lx "
+                       "lengen 0x%lx\n", tl, hd, status, lengen);
+       }
+
+       spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
+       __set_bit(IPATH_SDMA_DISABLED, &dd->ipath_sdma_status);
+       expected = test_bit(IPATH_SDMA_ABORTING, &dd->ipath_sdma_status);
+       spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
+       if (!expected)
+               ipath_cancel_sends(dd, 1);
+}
+
+static void handle_sdma_intr(struct ipath_devdata *dd, u64 istat)
+{
+       unsigned long flags;
+       int expected;
+
+       if ((istat & INFINIPATH_I_SDMAINT) &&
+           !test_bit(IPATH_SDMA_SHUTDOWN, &dd->ipath_sdma_status))
+               ipath_sdma_intr(dd);
+
+       if (istat & INFINIPATH_I_SDMADISABLED) {
+               expected = test_bit(IPATH_SDMA_ABORTING,
+                       &dd->ipath_sdma_status);
+               ipath_dbg("%s SDmaDisabled intr\n",
+                       expected ? "expected" : "unexpected");
+               spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
+               __set_bit(IPATH_SDMA_DISABLED, &dd->ipath_sdma_status);
+               spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
+               if (!expected)
+                       ipath_cancel_sends(dd, 1);
+               if (!test_bit(IPATH_SDMA_SHUTDOWN, &dd->ipath_sdma_status))
+                       tasklet_hi_schedule(&dd->ipath_sdma_abort_task);
+       }
+}
+
+static int handle_hdrq_full(struct ipath_devdata *dd)
+{
+       int chkerrpkts = 0;
+       u32 hd, tl;
+       u32 i;
+
+       ipath_stats.sps_hdrqfull++;
+       for (i = 0; i < dd->ipath_cfgports; i++) {
+               struct ipath_portdata *pd = dd->ipath_pd[i];
+
+               if (i == 0) {
+                       /*
+                        * For kernel receive queues, we just want to know
+                        * if there are packets in the queue that we can
+                        * process.
+                        */
+                       if (pd->port_head != ipath_get_hdrqtail(pd))
+                               chkerrpkts |= 1 << i;
+                       continue;
+               }
+
+               /* Skip if user context is not open */
+               if (!pd || !pd->port_cnt)
+                       continue;
+
+               /* Don't report the same point multiple times. */
+               if (dd->ipath_flags & IPATH_NODMA_RTAIL)
+                       tl = ipath_read_ureg32(dd, ur_rcvhdrtail, i);
+               else
+                       tl = ipath_get_rcvhdrtail(pd);
+               if (tl == pd->port_lastrcvhdrqtail)
+                       continue;
+
+               hd = ipath_read_ureg32(dd, ur_rcvhdrhead, i);
+               if (hd == (tl + 1) || (!hd && tl == dd->ipath_hdrqlast)) {
+                       pd->port_lastrcvhdrqtail = tl;
+                       pd->port_hdrqfull++;
+                       /* flush hdrqfull so that poll() sees it */
+                       wmb();
+                       wake_up_interruptible(&pd->port_wait);
+               }
+       }
+
+       return chkerrpkts;
+}
+
+static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
+{
+       char msg[128];
+       u64 ignore_this_time = 0;
+       u64 iserr = 0;
+       int chkerrpkts = 0, noprint = 0;
+       unsigned supp_msgs;
+       int log_idx;
+
+       /*
+        * don't report errors that are masked, either at init
+        * (not set in ipath_errormask), or temporarily (set in
+        * ipath_maskederrs)
+        */
+       errs &= dd->ipath_errormask & ~dd->ipath_maskederrs;
+
+       supp_msgs = handle_frequent_errors(dd, errs, msg, (u32)sizeof msg,
+               &noprint);
+
+       /* do these first, they are most important */
+       if (errs & INFINIPATH_E_HARDWARE) {
+               /* reuse same msg buf */
+               dd->ipath_f_handle_hwerrors(dd, msg, sizeof msg);
+       } else {
+               u64 mask;
+               for (log_idx = 0; log_idx < IPATH_EEP_LOG_CNT; ++log_idx) {
+                       mask = dd->ipath_eep_st_masks[log_idx].errs_to_log;
+                       if (errs & mask)
+                               ipath_inc_eeprom_err(dd, log_idx, 1);
+               }
+       }
+
+       if (errs & INFINIPATH_E_SDMAERRS)
+               handle_sdma_errors(dd, errs);
+
+       if (!noprint && (errs & ~dd->ipath_e_bitsextant))
+               ipath_dev_err(dd, "error interrupt with unknown errors "
+                             "%llx set\n", (unsigned long long)
+                             (errs & ~dd->ipath_e_bitsextant));
+
+       if (errs & E_SUM_ERRS)
+               ignore_this_time = handle_e_sum_errs(dd, errs);
+       else if ((errs & E_SUM_LINK_PKTERRS) &&
+           !(dd->ipath_flags & IPATH_LINKACTIVE)) {
+               /*
+                * This can happen when SMA is trying to bring the link
+                * up, but the IB link changes state at the "wrong" time.
+                * The IB logic then complains that the packet isn't
+                * valid.  We don't want to confuse people, so we just
+                * don't print them, except at debug
+                */
+               ipath_dbg("Ignoring packet errors %llx, because link not "
+                         "ACTIVE\n", (unsigned long long) errs);
+               ignore_this_time = errs & E_SUM_LINK_PKTERRS;
+       }
+
+       if (supp_msgs == 250000) {
+               int s_iserr;
+               /*
+                * It's not entirely reasonable assuming that the errors set
+                * in the last clear period are all responsible for the
+                * problem, but the alternative is to assume it's the only
+                * ones on this particular interrupt, which also isn't great
+                */
+               dd->ipath_maskederrs |= dd->ipath_lasterror | errs;
+
+               dd->ipath_errormask &= ~dd->ipath_maskederrs;
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
+                                dd->ipath_errormask);
+               s_iserr = ipath_decode_err(dd, msg, sizeof msg,
+                                          dd->ipath_maskederrs);
+
+               if (dd->ipath_maskederrs &
+                   ~(INFINIPATH_E_RRCVEGRFULL |
+                     INFINIPATH_E_RRCVHDRFULL | INFINIPATH_E_PKTERRS))
+                       ipath_dev_err(dd, "Temporarily disabling "
+                           "error(s) %llx reporting; too frequent (%s)\n",
+                               (unsigned long long) dd->ipath_maskederrs,
+                               msg);
+               else {
+                       /*
+                        * rcvegrfull and rcvhdrqfull are "normal",
+                        * for some types of processes (mostly benchmarks)
+                        * that send huge numbers of messages, while not
+                        * processing them.  So only complain about
+                        * these at debug level.
+                        */
+                       if (s_iserr)
+                               ipath_dbg("Temporarily disabling reporting "
+                                   "too frequent queue full errors (%s)\n",
+                                   msg);
+                       else
+                               ipath_cdbg(ERRPKT,
+                                   "Temporarily disabling reporting too"
+                                   " frequent packet errors (%s)\n",
+                                   msg);
+               }
+
+               /*
+                * Re-enable the masked errors after around 3 minutes.  in
+                * ipath_get_faststats().  If we have a series of fast
+                * repeating but different errors, the interval will keep
+                * stretching out, but that's OK, as that's pretty
+                * catastrophic.
+                */
+               dd->ipath_unmasktime = jiffies + HZ * 180;
+       }
+
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear, errs);
+       if (ignore_this_time)
+               errs &= ~ignore_this_time;
+       if (errs & ~dd->ipath_lasterror) {
+               errs &= ~dd->ipath_lasterror;
+               /* never suppress duplicate hwerrors or ibstatuschange */
+               dd->ipath_lasterror |= errs &
+                       ~(INFINIPATH_E_HARDWARE |
+                         INFINIPATH_E_IBSTATUSCHANGED);
+       }
+
+       if (errs & INFINIPATH_E_SENDSPECIALTRIGGER) {
+               dd->ipath_spectriggerhit++;
+               ipath_dbg("%lu special trigger hits\n",
+                       dd->ipath_spectriggerhit);
+       }
+
+       /* likely due to cancel; so suppress message unless verbose */
+       if ((errs & (INFINIPATH_E_SPKTLEN | INFINIPATH_E_SPIOARMLAUNCH)) &&
+               time_after(dd->ipath_lastcancel, jiffies)) {
+               /* armlaunch takes precedence; it often causes both. */
+               ipath_cdbg(VERBOSE,
+                       "Suppressed %s error (%llx) after sendbuf cancel\n",
+                       (errs &  INFINIPATH_E_SPIOARMLAUNCH) ?
+                       "armlaunch" : "sendpktlen", (unsigned long long)errs);
+               errs &= ~(INFINIPATH_E_SPIOARMLAUNCH | INFINIPATH_E_SPKTLEN);
+       }
+
+       if (!errs)
+               return 0;
+
+       if (!noprint) {
+               ipath_err_t mask;
+               /*
+                * The ones we mask off are handled specially below
+                * or above.  Also mask SDMADISABLED by default as it
+                * is too chatty.
+                */
+               mask = INFINIPATH_E_IBSTATUSCHANGED |
+                       INFINIPATH_E_RRCVEGRFULL | INFINIPATH_E_RRCVHDRFULL |
+                       INFINIPATH_E_HARDWARE | INFINIPATH_E_SDMADISABLED;
+
+               /* if we're in debug, then don't mask SDMADISABLED msgs */
+               if (ipath_debug & __IPATH_DBG)
+                       mask &= ~INFINIPATH_E_SDMADISABLED;
+
+               ipath_decode_err(dd, msg, sizeof msg, errs & ~mask);
+       } else
+               /* so we don't need if (!noprint) at strlcat's below */
+               *msg = 0;
+
+       if (errs & E_SUM_PKTERRS) {
+               ipath_stats.sps_pkterrs++;
+               chkerrpkts = 1;
+       }
+       if (errs & E_SUM_ERRS)
+               ipath_stats.sps_errs++;
+
+       if (errs & (INFINIPATH_E_RICRC | INFINIPATH_E_RVCRC)) {
+               ipath_stats.sps_crcerrs++;
+               chkerrpkts = 1;
+       }
+       iserr = errs & ~(E_SUM_PKTERRS | INFINIPATH_E_PKTERRS);
+
+
+       /*
+        * We don't want to print these two as they happen, or we can make
+        * the situation even worse, because it takes so long to print
+        * messages to serial consoles.  Kernel ports get printed from
+        * fast_stats, no more than every 5 seconds, user ports get printed
+        * on close
+        */
+       if (errs & INFINIPATH_E_RRCVHDRFULL)
+               chkerrpkts |= handle_hdrq_full(dd);
+       if (errs & INFINIPATH_E_RRCVEGRFULL) {
+               struct ipath_portdata *pd = dd->ipath_pd[0];
+
+               /*
+                * since this is of less importance and not likely to
+                * happen without also getting hdrfull, only count
+                * occurrences; don't check each port (or even the kernel
+                * vs user)
+                */
+               ipath_stats.sps_etidfull++;
+               if (pd->port_head != ipath_get_hdrqtail(pd))
+                       chkerrpkts |= 1;
+       }
+
+       /*
+        * do this before IBSTATUSCHANGED, in case both bits set in a single
+        * interrupt; we want the STATUSCHANGE to "win", so we do our
+        * internal copy of state machine correctly
+        */
+       if (errs & INFINIPATH_E_RIBLOSTLINK) {
+               /*
+                * force through block below
+                */
+               errs |= INFINIPATH_E_IBSTATUSCHANGED;
+               ipath_stats.sps_iblink++;
+               dd->ipath_flags |= IPATH_LINKDOWN;
+               dd->ipath_flags &= ~(IPATH_LINKUNK | IPATH_LINKINIT
+                                    | IPATH_LINKARMED | IPATH_LINKACTIVE);
+               *dd->ipath_statusp &= ~IPATH_STATUS_IB_READY;
+
+               ipath_dbg("Lost link, link now down (%s)\n",
+                       ipath_ibcstatus_str[ipath_read_kreg64(dd,
+                       dd->ipath_kregs->kr_ibcstatus) & 0xf]);
+       }
+       if (errs & INFINIPATH_E_IBSTATUSCHANGED)
+               handle_e_ibstatuschanged(dd, errs);
+
+       if (errs & INFINIPATH_E_RESET) {
+               if (!noprint)
+                       ipath_dev_err(dd, "Got reset, requires re-init "
+                                     "(unload and reload driver)\n");
+               dd->ipath_flags &= ~IPATH_INITTED;      /* needs re-init */
+               /* mark as having had error */
+               *dd->ipath_statusp |= IPATH_STATUS_HWERROR;
+               *dd->ipath_statusp &= ~IPATH_STATUS_IB_CONF;
+       }
+
+       if (!noprint && *msg) {
+               if (iserr)
+                       ipath_dev_err(dd, "%s error\n", msg);
+       }
+       if (dd->ipath_state_wanted & dd->ipath_flags) {
+               ipath_cdbg(VERBOSE, "driver wanted state %x, iflags now %x, "
+                          "waking\n", dd->ipath_state_wanted,
+                          dd->ipath_flags);
+               wake_up_interruptible(&ipath_state_wait);
+       }
+
+       return chkerrpkts;
+}
+
+/*
+ * try to cleanup as much as possible for anything that might have gone
+ * wrong while in freeze mode, such as pio buffers being written by user
+ * processes (causing armlaunch), send errors due to going into freeze mode,
+ * etc., and try to avoid causing extra interrupts while doing so.
+ * Forcibly update the in-memory pioavail register copies after cleanup
+ * because the chip won't do it while in freeze mode (the register values
+ * themselves are kept correct).
+ * Make sure that we don't lose any important interrupts by using the chip
+ * feature that says that writing 0 to a bit in *clear that is set in
+ * *status will cause an interrupt to be generated again (if allowed by
+ * the *mask value).
+ */
+void ipath_clear_freeze(struct ipath_devdata *dd)
+{
+       /* disable error interrupts, to avoid confusion */
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
+
+       /* also disable interrupts; errormask is sometimes overwriten */
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);
+
+       ipath_cancel_sends(dd, 1);
+
+       /* clear the freeze, and be sure chip saw it */
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_control,
+                        dd->ipath_control);
+       ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+
+       /* force in-memory update now we are out of freeze */
+       ipath_force_pio_avail_update(dd);
+
+       /*
+        * force new interrupt if any hwerr, error or interrupt bits are
+        * still set, and clear "safe" send packet errors related to freeze
+        * and cancelling sends.  Re-enable error interrupts before possible
+        * force of re-interrupt on pending interrupts.
+        */
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear, 0ULL);
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear,
+               E_SPKT_ERRS_IGNORE);
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
+               dd->ipath_errormask);
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, -1LL);
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, 0ULL);
+}
+
+
+/* this is separate to allow for better optimization of ipath_intr() */
+
+static noinline void ipath_bad_intr(struct ipath_devdata *dd, u32 *unexpectp)
+{
+       /*
+        * sometimes happen during driver init and unload, don't want
+        * to process any interrupts at that point
+        */
+
+       /* this is just a bandaid, not a fix, if something goes badly
+        * wrong */
+       if (++*unexpectp > 100) {
+               if (++*unexpectp > 105) {
+                       /*
+                        * ok, we must be taking somebody else's interrupts,
+                        * due to a messed up mptable and/or PIRQ table, so
+                        * unregister the interrupt.  We've seen this during
+                        * linuxbios development work, and it may happen in
+                        * the future again.
+                        */
+                       if (dd->pcidev && dd->ipath_irq) {
+                               ipath_dev_err(dd, "Now %u unexpected "
+                                             "interrupts, unregistering "
+                                             "interrupt handler\n",
+                                             *unexpectp);
+                               ipath_dbg("free_irq of irq %d\n",
+                                         dd->ipath_irq);
+                               dd->ipath_f_free_irq(dd);
+                       }
+               }
+               if (ipath_read_ireg(dd, dd->ipath_kregs->kr_intmask)) {
+                       ipath_dev_err(dd, "%u unexpected interrupts, "
+                                     "disabling interrupts completely\n",
+                                     *unexpectp);
+                       /*
+                        * disable all interrupts, something is very wrong
+                        */
+                       ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask,
+                                        0ULL);
+               }
+       } else if (*unexpectp > 1)
+               ipath_dbg("Interrupt when not ready, should not happen, "
+                         "ignoring\n");
+}
+
+static noinline void ipath_bad_regread(struct ipath_devdata *dd)
+{
+       static int allbits;
+
+       /* separate routine, for better optimization of ipath_intr() */
+
+       /*
+        * We print the message and disable interrupts, in hope of
+        * having a better chance of debugging the problem.
+        */
+       ipath_dev_err(dd,
+                     "Read of interrupt status failed (all bits set)\n");
+       if (allbits++) {
+               /* disable all interrupts, something is very wrong */
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);
+               if (allbits == 2) {
+                       ipath_dev_err(dd, "Still bad interrupt status, "
+                                     "unregistering interrupt\n");
+                       dd->ipath_f_free_irq(dd);
+               } else if (allbits > 2) {
+                       if ((allbits % 10000) == 0)
+                               printk(".");
+               } else
+                       ipath_dev_err(dd, "Disabling interrupts, "
+                                     "multiple errors\n");
+       }
+}
+
+static void handle_layer_pioavail(struct ipath_devdata *dd)
+{
+       unsigned long flags;
+       int ret;
+
+       ret = ipath_ib_piobufavail(dd->verbs_dev);
+       if (ret > 0)
+               goto set;
+
+       return;
+set:
+       spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+       dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+                        dd->ipath_sendctrl);
+       ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+       spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+}
+
+/*
+ * Handle receive interrupts for user ports; this means a user
+ * process was waiting for a packet to arrive, and didn't want
+ * to poll
+ */
+static void handle_urcv(struct ipath_devdata *dd, u64 istat)
+{
+       u64 portr;
+       int i;
+       int rcvdint = 0;
+
+       /*
+        * test_and_clear_bit(IPATH_PORT_WAITING_RCV) and
+        * test_and_clear_bit(IPATH_PORT_WAITING_URG) below
+        * would both like timely updates of the bits so that
+        * we don't pass them by unnecessarily.  the rmb()
+        * here ensures that we see them promptly -- the
+        * corresponding wmb()'s are in ipath_poll_urgent()
+        * and ipath_poll_next()...
+        */
+       rmb();
+       portr = ((istat >> dd->ipath_i_rcvavail_shift) &
+                dd->ipath_i_rcvavail_mask) |
+               ((istat >> dd->ipath_i_rcvurg_shift) &
+                dd->ipath_i_rcvurg_mask);
+       for (i = 1; i < dd->ipath_cfgports; i++) {
+               struct ipath_portdata *pd = dd->ipath_pd[i];
+
+               if (portr & (1 << i) && pd && pd->port_cnt) {
+                       if (test_and_clear_bit(IPATH_PORT_WAITING_RCV,
+                                              &pd->port_flag)) {
+                               clear_bit(i + dd->ipath_r_intravail_shift,
+                                         &dd->ipath_rcvctrl);
+                               wake_up_interruptible(&pd->port_wait);
+                               rcvdint = 1;
+                       } else if (test_and_clear_bit(IPATH_PORT_WAITING_URG,
+                                                     &pd->port_flag)) {
+                               pd->port_urgent++;
+                               wake_up_interruptible(&pd->port_wait);
+                       }
+               }
+       }
+       if (rcvdint) {
+               /* only want to take one interrupt, so turn off the rcv
+                * interrupt for all the ports that we set the rcv_waiting
+                * (but never for kernel port)
+                */
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+                                dd->ipath_rcvctrl);
+       }
+}
+
+irqreturn_t ipath_intr(int irq, void *data)
+{
+       struct ipath_devdata *dd = data;
+       u64 istat, chk0rcv = 0;
+       ipath_err_t estat = 0;
+       irqreturn_t ret;
+       static unsigned unexpected = 0;
+       u64 kportrbits;
+
+       ipath_stats.sps_ints++;
+
+       if (dd->ipath_int_counter != (u32) -1)
+               dd->ipath_int_counter++;
+
+       if (!(dd->ipath_flags & IPATH_PRESENT)) {
+               /*
+                * This return value is not great, but we do not want the
+                * interrupt core code to remove our interrupt handler
+                * because we don't appear to be handling an interrupt
+                * during a chip reset.
+                */
+               return IRQ_HANDLED;
+       }
+
+       /*
+        * this needs to be flags&initted, not statusp, so we keep
+        * taking interrupts even after link goes down, etc.
+        * Also, we *must* clear the interrupt at some point, or we won't
+        * take it again, which can be real bad for errors, etc...
+        */
+
+       if (!(dd->ipath_flags & IPATH_INITTED)) {
+               ipath_bad_intr(dd, &unexpected);
+               ret = IRQ_NONE;
+               goto bail;
+       }
+
+       istat = ipath_read_ireg(dd, dd->ipath_kregs->kr_intstatus);
+
+       if (unlikely(!istat)) {
+               ipath_stats.sps_nullintr++;
+               ret = IRQ_NONE; /* not our interrupt, or already handled */
+               goto bail;
+       }
+       if (unlikely(istat == -1)) {
+               ipath_bad_regread(dd);
+               /* don't know if it was our interrupt or not */
+               ret = IRQ_NONE;
+               goto bail;
+       }
+
+       if (unexpected)
+               unexpected = 0;
+
+       if (unlikely(istat & ~dd->ipath_i_bitsextant))
+               ipath_dev_err(dd,
+                             "interrupt with unknown interrupts %Lx set\n",
+                             (unsigned long long)
+                             istat & ~dd->ipath_i_bitsextant);
+       else if (istat & ~INFINIPATH_I_ERROR) /* errors do own printing */
+               ipath_cdbg(VERBOSE, "intr stat=0x%Lx\n",
+                       (unsigned long long) istat);
+
+       if (istat & INFINIPATH_I_ERROR) {
+               ipath_stats.sps_errints++;
+               estat = ipath_read_kreg64(dd,
+                                         dd->ipath_kregs->kr_errorstatus);
+               if (!estat)
+                       dev_info(&dd->pcidev->dev, "error interrupt (%Lx), "
+                                "but no error bits set!\n",
+                                (unsigned long long) istat);
+               else if (estat == -1LL)
+                       /*
+                        * should we try clearing all, or hope next read
+                        * works?
+                        */
+                       ipath_dev_err(dd, "Read of error status failed "
+                                     "(all bits set); ignoring\n");
+               else
+                       chk0rcv |= handle_errors(dd, estat);
+       }
+
+       if (istat & INFINIPATH_I_GPIO) {
+               /*
+                * GPIO interrupts fall in two broad classes:
+                * GPIO_2 indicates (on some HT4xx boards) that a packet
+                *        has arrived for Port 0. Checking for this
+                *        is controlled by flag IPATH_GPIO_INTR.
+                * GPIO_3..5 on IBA6120 Rev2 and IBA6110 Rev4 chips indicate
+                *        errors that we need to count. Checking for this
+                *        is controlled by flag IPATH_GPIO_ERRINTRS.
+                */
+               u32 gpiostatus;
+               u32 to_clear = 0;
+
+               gpiostatus = ipath_read_kreg32(
+                       dd, dd->ipath_kregs->kr_gpio_status);
+               /* First the error-counter case. */
+               if ((gpiostatus & IPATH_GPIO_ERRINTR_MASK) &&
+                   (dd->ipath_flags & IPATH_GPIO_ERRINTRS)) {
+                       /* want to clear the bits we see asserted. */
+                       to_clear |= (gpiostatus & IPATH_GPIO_ERRINTR_MASK);
+
+                       /*
+                        * Count appropriately, clear bits out of our copy,
+                        * as they have been "handled".
+                        */
+                       if (gpiostatus & (1 << IPATH_GPIO_RXUVL_BIT)) {
+                               ipath_dbg("FlowCtl on UnsupVL\n");
+                               dd->ipath_rxfc_unsupvl_errs++;
+                       }
+                       if (gpiostatus & (1 << IPATH_GPIO_OVRUN_BIT)) {
+                               ipath_dbg("Overrun Threshold exceeded\n");
+                               dd->ipath_overrun_thresh_errs++;
+                       }
+                       if (gpiostatus & (1 << IPATH_GPIO_LLI_BIT)) {
+                               ipath_dbg("Local Link Integrity error\n");
+                               dd->ipath_lli_errs++;
+                       }
+                       gpiostatus &= ~IPATH_GPIO_ERRINTR_MASK;
+               }
+               /* Now the Port0 Receive case */
+               if ((gpiostatus & (1 << IPATH_GPIO_PORT0_BIT)) &&
+                   (dd->ipath_flags & IPATH_GPIO_INTR)) {
+                       /*
+                        * GPIO status bit 2 is set, and we expected it.
+                        * clear it and indicate in p0bits.
+                        * This probably only happens if a Port0 pkt
+                        * arrives at _just_ the wrong time, and we
+                        * handle that by seting chk0rcv;
+                        */
+                       to_clear |= (1 << IPATH_GPIO_PORT0_BIT);
+                       gpiostatus &= ~(1 << IPATH_GPIO_PORT0_BIT);
+                       chk0rcv = 1;
+               }
+               if (gpiostatus) {
+                       /*
+                        * Some unexpected bits remain. If they could have
+                        * caused the interrupt, complain and clear.
+                        * To avoid repetition of this condition, also clear
+                        * the mask. It is almost certainly due to error.
+                        */
+                       const u32 mask = (u32) dd->ipath_gpio_mask;
+
+                       if (mask & gpiostatus) {
+                               ipath_dbg("Unexpected GPIO IRQ bits %x\n",
+                                 gpiostatus & mask);
+                               to_clear |= (gpiostatus & mask);
+                               dd->ipath_gpio_mask &= ~(gpiostatus & mask);
+                               ipath_write_kreg(dd,
+                                       dd->ipath_kregs->kr_gpio_mask,
+                                       dd->ipath_gpio_mask);
+                       }
+               }
+               if (to_clear) {
+                       ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_clear,
+                                       (u64) to_clear);
+               }
+       }
+
+       /*
+        * Clear the interrupt bits we found set, unless they are receive
+        * related, in which case we already cleared them above, and don't
+        * want to clear them again, because we might lose an interrupt.
+        * Clear it early, so we "know" know the chip will have seen this by
+        * the time we process the queue, and will re-interrupt if necessary.
+        * The processor itself won't take the interrupt again until we return.
+        */
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, istat);
+
+       /*
+        * Handle kernel receive queues before checking for pio buffers
+        * available since receives can overflow; piobuf waiters can afford
+        * a few extra cycles, since they were waiting anyway, and user's
+        * waiting for receive are at the bottom.
+        */
+       kportrbits = (1ULL << dd->ipath_i_rcvavail_shift) |
+               (1ULL << dd->ipath_i_rcvurg_shift);
+       if (chk0rcv || (istat & kportrbits)) {
+               istat &= ~kportrbits;
+               ipath_kreceive(dd->ipath_pd[0]);
+       }
+
+       if (istat & ((dd->ipath_i_rcvavail_mask << dd->ipath_i_rcvavail_shift) |
+                    (dd->ipath_i_rcvurg_mask << dd->ipath_i_rcvurg_shift)))
+               handle_urcv(dd, istat);
+
+       if (istat & (INFINIPATH_I_SDMAINT | INFINIPATH_I_SDMADISABLED))
+               handle_sdma_intr(dd, istat);
+
+       if (istat & INFINIPATH_I_SPIOBUFAVAIL) {
+               unsigned long flags;
+
+               spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+               dd->ipath_sendctrl &= ~INFINIPATH_S_PIOINTBUFAVAIL;
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+                                dd->ipath_sendctrl);
+               ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+               spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+
+               /* always process; sdma verbs uses PIO for acks and VL15  */
+               handle_layer_pioavail(dd);
+       }
+
+       ret = IRQ_HANDLED;
+
+bail:
+       return ret;
+}