]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/infiniband/hw/ipath/ipath_driver.c
IB/ipath: Misc changes to prepare for IB7220 introduction
[linux-2.6-omap-h63xx.git] / drivers / infiniband / hw / ipath / ipath_driver.c
index ca4d0acc6786768177126ca15af89407fbba235a..c94bc4730b2b80b0d0dec2364451d47022b3cdc7 100644 (file)
@@ -41,7 +41,6 @@
 
 #include "ipath_kernel.h"
 #include "ipath_verbs.h"
-#include "ipath_common.h"
 
 static void ipath_update_pio_bufs(struct ipath_devdata *);
 
@@ -73,10 +72,27 @@ module_param_named(debug, ipath_debug, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(debug, "mask for debug prints");
 EXPORT_SYMBOL_GPL(ipath_debug);
 
+unsigned ipath_mtu4096 = 1; /* max 4KB IB mtu by default, if supported */
+module_param_named(mtu4096, ipath_mtu4096, uint, S_IRUGO);
+MODULE_PARM_DESC(mtu4096, "enable MTU of 4096 bytes, if supported");
+
+static unsigned ipath_hol_timeout_ms = 13000;
+module_param_named(hol_timeout_ms, ipath_hol_timeout_ms, uint, S_IRUGO);
+MODULE_PARM_DESC(hol_timeout_ms,
+       "duration of user app suspension after link failure");
+
+unsigned ipath_linkrecovery = 1;
+module_param_named(linkrecovery, ipath_linkrecovery, uint, S_IWUSR | S_IRUGO);
+MODULE_PARM_DESC(linkrecovery, "enable workaround for link recovery issue");
+
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("QLogic <support@pathscale.com>");
+MODULE_AUTHOR("QLogic <support@qlogic.com>");
 MODULE_DESCRIPTION("QLogic InfiniPath driver");
 
+/*
+ * Table to translate the LINKTRAININGSTATE portion of
+ * IBCStatus to a human-readable form.
+ */
 const char *ipath_ibcstatus_str[] = {
        "Disabled",
        "LinkUp",
@@ -91,9 +107,20 @@ const char *ipath_ibcstatus_str[] = {
        "CfgWaitRmt",
        "CfgIdle",
        "RecovRetrain",
-       "LState0xD",            /* unused */
+       "CfgTxRevLane",         /* unused before IBA7220 */
        "RecovWaitRmt",
        "RecovIdle",
+       /* below were added for IBA7220 */
+       "CfgEnhanced",
+       "CfgTest",
+       "CfgWaitRmtTest",
+       "CfgWaitCfgEnhanced",
+       "SendTS_T",
+       "SendTstIdles",
+       "RcvTS_T",
+       "SendTst_TS1s",
+       "LTState18", "LTState19", "LTState1A", "LTState1B",
+       "LTState1C", "LTState1D", "LTState1E", "LTState1F"
 };
 
 static void __devexit ipath_remove_one(struct pci_dev *);
@@ -126,19 +153,6 @@ static struct pci_driver ipath_driver = {
        },
 };
 
-static void ipath_check_status(struct work_struct *work)
-{
-       struct ipath_devdata *dd = container_of(work, struct ipath_devdata,
-                                               status_work.work);
-
-       /*
-        * If we don't have any interrupts, let the user know and
-        * don't bother checking again.
-        */
-       if (dd->ipath_int_counter == 0)
-               dev_err(&dd->pcidev->dev, "No interrupts detected.\n");
-}
-
 static inline void read_bars(struct ipath_devdata *dd, struct pci_dev *dev,
                             u32 *bar0, u32 *bar1)
 {
@@ -206,8 +220,6 @@ static struct ipath_devdata *ipath_alloc_devdata(struct pci_dev *pdev)
        dd->pcidev = pdev;
        pci_set_drvdata(pdev, dd);
 
-       INIT_DELAYED_WORK(&dd->status_work, ipath_check_status);
-
        list_add(&dd->ipath_list, &ipath_dev_list);
 
 bail_unlock:
@@ -234,12 +246,12 @@ struct ipath_devdata *ipath_lookup(int unit)
        return dd;
 }
 
-int ipath_count_units(int *npresentp, int *nupp, u32 *maxportsp)
+int ipath_count_units(int *npresentp, int *nupp, int *maxportsp)
 {
        int nunits, npresent, nup;
        struct ipath_devdata *dd;
        unsigned long flags;
-       u32 maxports;
+       int maxports;
 
        nunits = npresent = nup = maxports = 0;
 
@@ -304,7 +316,7 @@ static void ipath_verify_pioperf(struct ipath_devdata *dd)
        u32 *addr;
        u64 msecs, emsecs;
 
-       piobuf = ipath_getpiobuf(dd, &pbnum);
+       piobuf = ipath_getpiobuf(dd, 0, &pbnum);
        if (!piobuf) {
                dev_info(&dd->pcidev->dev,
                        "No PIObufs for checking perf, skipping\n");
@@ -336,7 +348,14 @@ static void ipath_verify_pioperf(struct ipath_devdata *dd)
 
        ipath_disable_armlaunch(dd);
 
-       writeq(0, piobuf); /* length 0, no dwords actually sent */
+       /*
+        * length 0, no dwords actually sent, and mark as VL15
+        * on chips where that may matter (due to IB flowcontrol)
+        */
+       if ((dd->ipath_flags & IPATH_HAS_PBC_CNT))
+               writeq(1UL << 63, piobuf);
+       else
+               writeq(0, piobuf);
        ipath_flush_wc();
 
        /*
@@ -377,6 +396,7 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
        struct ipath_devdata *dd;
        unsigned long long addr;
        u32 bar0 = 0, bar1 = 0;
+       u8 rev;
 
        dd = ipath_alloc_devdata(pdev);
        if (IS_ERR(dd)) {
@@ -408,7 +428,7 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
        }
        addr = pci_resource_start(pdev, 0);
        len = pci_resource_len(pdev, 0);
-       ipath_cdbg(VERBOSE, "regbase (0) %llx len %d pdev->irq %d, vend %x/%x "
+       ipath_cdbg(VERBOSE, "regbase (0) %llx len %d irq %d, vend %x/%x "
                   "driver_data %lx\n", addr, len, pdev->irq, ent->vendor,
                   ent->device, ent->driver_data);
 
@@ -533,7 +553,13 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
                goto bail_regions;
        }
 
-       dd->ipath_pcirev = pdev->revision;
+       ret = pci_read_config_byte(pdev, PCI_REVISION_ID, &rev);
+       if (ret) {
+               ipath_dev_err(dd, "Failed to read PCI revision ID unit "
+                             "%u: err %d\n", dd->ipath_unit, -ret);
+               goto bail_regions;      /* shouldn't ever happen */
+       }
+       dd->ipath_pcirev = rev;
 
 #if defined(__powerpc__)
        /* There isn't a generic way to specify writethrough mappings */
@@ -556,14 +582,6 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
        ipath_cdbg(VERBOSE, "mapped io addr %llx to kregbase %p\n",
                   addr, dd->ipath_kregbase);
 
-       /*
-        * clear ipath_flags here instead of in ipath_init_chip as it is set
-        * by ipath_setup_htconfig.
-        */
-       dd->ipath_flags = 0;
-       dd->ipath_lli_counter = 0;
-       dd->ipath_lli_errors = 0;
-
        if (dd->ipath_f_bus(dd, pdev))
                ipath_dev_err(dd, "Failed to setup config space; "
                              "continuing anyway\n");
@@ -608,13 +626,11 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
        ipath_diag_add(dd);
        ipath_register_ib_device(dd);
 
-       /* Check that card status in STATUS_TIMEOUT seconds. */
-       schedule_delayed_work(&dd->status_work, HZ * STATUS_TIMEOUT);
-
        goto bail;
 
 bail_irqsetup:
-       if (pdev->irq) free_irq(pdev->irq, dd);
+       if (pdev->irq)
+               free_irq(pdev->irq, dd);
 
 bail_iounmap:
        iounmap((volatile void __iomem *) dd->ipath_kregbase);
@@ -654,6 +670,10 @@ static void __devexit cleanup_device(struct ipath_devdata *dd)
                ipath_disable_wc(dd);
        }
 
+       if (dd->ipath_spectriggerhit)
+               dev_info(&dd->pcidev->dev, "%lu special trigger hits\n",
+                        dd->ipath_spectriggerhit);
+
        if (dd->ipath_pioavailregs_dma) {
                dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
                                  (void *) dd->ipath_pioavailregs_dma,
@@ -706,6 +726,8 @@ static void __devexit cleanup_device(struct ipath_devdata *dd)
                tmpp = dd->ipath_pageshadow;
                dd->ipath_pageshadow = NULL;
                vfree(tmpp);
+
+               dd->ipath_egrtidbase = NULL;
        }
 
        /*
@@ -738,7 +760,6 @@ static void __devexit ipath_remove_one(struct pci_dev *pdev)
         */
        ipath_shutdown_device(dd);
 
-       cancel_delayed_work(&dd->status_work);
        flush_scheduled_work();
 
        if (dd->verbs_dev)
@@ -823,20 +844,8 @@ void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first,
                ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
                spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
        }
-
-       /*
-        * Disable PIOAVAILUPD, then re-enable, reading scratch in
-        * between.  This seems to avoid a chip timing race that causes
-        * pioavail updates to memory to stop.  We xor as we don't
-        * know the state of the bit when we're called.
-        */
-       spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
-       ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-               dd->ipath_sendctrl ^ INFINIPATH_S_PIOBUFAVAILUPD);
-       ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
-       ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-                        dd->ipath_sendctrl);
-       spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+       /* on some older chips, update may not happen after cancel */
+       ipath_force_pio_avail_update(dd);
 }
 
 /**
@@ -873,7 +882,7 @@ int ipath_wait_linkstate(struct ipath_devdata *dd, u32 state, int msecs)
                           (unsigned long long) ipath_read_kreg64(
                                   dd, dd->ipath_kregs->kr_ibcctrl),
                           (unsigned long long) val,
-                          ipath_ibcstatus_str[val & 0xf]);
+                          ipath_ibcstatus_str[val & dd->ibcs_lts_mask]);
        }
        return (dd->ipath_flags & state) ? 0 : -ETIMEDOUT;
 }
@@ -922,6 +931,8 @@ int ipath_decode_err(char *buf, size_t blen, ipath_err_t err)
                strlcat(buf, "rbadversion ", blen);
        if (err & INFINIPATH_E_RHDR)
                strlcat(buf, "rhdr ", blen);
+       if (err & INFINIPATH_E_SENDSPECIALTRIGGER)
+               strlcat(buf, "sendspecialtrigger ", blen);
        if (err & INFINIPATH_E_RLONGPKTLEN)
                strlcat(buf, "rlongpktlen ", blen);
        if (err & INFINIPATH_E_RMAXPKTLEN)
@@ -964,6 +975,8 @@ int ipath_decode_err(char *buf, size_t blen, ipath_err_t err)
                strlcat(buf, "hardware ", blen);
        if (err & INFINIPATH_E_RESET)
                strlcat(buf, "reset ", blen);
+       if (err & INFINIPATH_E_INVALIDEEPCMD)
+               strlcat(buf, "invalideepromcmd ", blen);
 done:
        return iserr;
 }
@@ -1076,18 +1089,17 @@ static void ipath_rcv_hdrerr(struct ipath_devdata *dd,
                             u32 eflags,
                             u32 l,
                             u32 etail,
-                            u64 *rc)
+                            __le32 *rhf_addr,
+                            struct ipath_message_header *hdr)
 {
        char emsg[128];
-       struct ipath_message_header *hdr;
 
        get_rhf_errstring(eflags, emsg, sizeof emsg);
-       hdr = (struct ipath_message_header *)&rc[1];
        ipath_cdbg(PKT, "RHFerrs %x hdrqtail=%x typ=%u "
                   "tlen=%x opcode=%x egridx=%x: %s\n",
                   eflags, l,
-                  ipath_hdrget_rcv_type((__le32 *) rc),
-                  ipath_hdrget_length_in_bytes((__le32 *) rc),
+                  ipath_hdrget_rcv_type(rhf_addr),
+                  ipath_hdrget_length_in_bytes(rhf_addr),
                   be32_to_cpu(hdr->bth[0]) >> 24,
                   etail, emsg);
 
@@ -1112,55 +1124,52 @@ static void ipath_rcv_hdrerr(struct ipath_devdata *dd,
  */
 void ipath_kreceive(struct ipath_portdata *pd)
 {
-       u64 *rc;
        struct ipath_devdata *dd = pd->port_dd;
+       __le32 *rhf_addr;
        void *ebuf;
        const u32 rsize = dd->ipath_rcvhdrentsize;      /* words */
        const u32 maxcnt = dd->ipath_rcvhdrcnt * rsize; /* words */
        u32 etail = -1, l, hdrqtail;
        struct ipath_message_header *hdr;
-       u32 eflags, i, etype, tlen, pkttot = 0, updegr=0, reloop=0;
+       u32 eflags, i, etype, tlen, pkttot = 0, updegr = 0, reloop = 0;
        static u64 totcalls;    /* stats, may eventually remove */
-
-       if (!dd->ipath_hdrqtailptr) {
-               ipath_dev_err(dd,
-                             "hdrqtailptr not set, can't do receives\n");
-               goto bail;
-       }
+       int last;
 
        l = pd->port_head;
-       hdrqtail = ipath_get_rcvhdrtail(pd);
-       if (l == hdrqtail)
-               goto bail;
-
-reloop:
-       for (i = 0; l != hdrqtail; i++) {
-               u32 qp;
-               u8 *bthbytes;
+       rhf_addr = (__le32 *) pd->port_rcvhdrq + l + dd->ipath_rhf_offset;
+       if (dd->ipath_flags & IPATH_NODMA_RTAIL) {
+               u32 seq = ipath_hdrget_seq(rhf_addr);
 
-               rc = (u64 *) (pd->port_rcvhdrq + (l << 2));
-               hdr = (struct ipath_message_header *)&rc[1];
-               /*
-                * could make a network order version of IPATH_KD_QP, and
-                * do the obvious shift before masking to speed this up.
-                */
-               qp = ntohl(hdr->bth[1]) & 0xffffff;
-               bthbytes = (u8 *) hdr->bth;
+               if (seq != pd->port_seq_cnt)
+                       goto bail;
+               hdrqtail = 0;
+       } else {
+               hdrqtail = ipath_get_rcvhdrtail(pd);
+               if (l == hdrqtail)
+                       goto bail;
+               smp_rmb();
+       }
 
-               eflags = ipath_hdrget_err_flags((__le32 *) rc);
-               etype = ipath_hdrget_rcv_type((__le32 *) rc);
+reloop:
+       for (last = 0, i = 1; !last; i++) {
+               hdr = dd->ipath_f_get_msgheader(dd, rhf_addr);
+               eflags = ipath_hdrget_err_flags(rhf_addr);
+               etype = ipath_hdrget_rcv_type(rhf_addr);
                /* total length */
-               tlen = ipath_hdrget_length_in_bytes((__le32 *) rc);
+               tlen = ipath_hdrget_length_in_bytes(rhf_addr);
                ebuf = NULL;
-               if (etype != RCVHQ_RCV_TYPE_EXPECTED) {
+               if ((dd->ipath_flags & IPATH_NODMA_RTAIL) ?
+                   ipath_hdrget_use_egr_buf(rhf_addr) :
+                   (etype != RCVHQ_RCV_TYPE_EXPECTED)) {
                        /*
-                        * it turns out that the chips uses an eager buffer
+                        * It turns out that the chip uses an eager buffer
                         * for all non-expected packets, whether it "needs"
                         * one or not.  So always get the index, but don't
                         * set ebuf (so we try to copy data) unless the
                         * length requires it.
                         */
-                       etail = ipath_hdrget_index((__le32 *) rc);
+                       etail = ipath_hdrget_index(rhf_addr);
+                       updegr = 1;
                        if (tlen > sizeof(*hdr) ||
                            etype == RCVHQ_RCV_TYPE_NON_KD)
                                ebuf = ipath_get_egrbuf(dd, etail);
@@ -1171,75 +1180,91 @@ reloop:
                 * packets; only ipathhdrerr should be set.
                 */
 
-               if (etype != RCVHQ_RCV_TYPE_NON_KD && etype !=
-                   RCVHQ_RCV_TYPE_ERROR && ipath_hdrget_ipath_ver(
-                           hdr->iph.ver_port_tid_offset) !=
-                   IPS_PROTO_VERSION) {
+               if (etype != RCVHQ_RCV_TYPE_NON_KD &&
+                   etype != RCVHQ_RCV_TYPE_ERROR &&
+                   ipath_hdrget_ipath_ver(hdr->iph.ver_port_tid_offset) !=
+                   IPS_PROTO_VERSION)
                        ipath_cdbg(PKT, "Bad InfiniPath protocol version "
                                   "%x\n", etype);
-               }
 
                if (unlikely(eflags))
-                       ipath_rcv_hdrerr(dd, eflags, l, etail, rc);
+                       ipath_rcv_hdrerr(dd, eflags, l, etail, rhf_addr, hdr);
                else if (etype == RCVHQ_RCV_TYPE_NON_KD) {
-                       ipath_ib_rcv(dd->verbs_dev, rc + 1, ebuf, tlen);
+                       ipath_ib_rcv(dd->verbs_dev, (u32 *)hdr, ebuf, tlen);
                        if (dd->ipath_lli_counter)
                                dd->ipath_lli_counter--;
+               } else if (etype == RCVHQ_RCV_TYPE_EAGER) {
+                       u8 opcode = be32_to_cpu(hdr->bth[0]) >> 24;
+                       u32 qp = be32_to_cpu(hdr->bth[1]) & 0xffffff;
                        ipath_cdbg(PKT, "typ %x, opcode %x (eager, "
                                   "qp=%x), len %x; ignored\n",
-                                  etype, bthbytes[0], qp, tlen);
+                                  etype, opcode, qp, tlen);
                }
-               else if (etype == RCVHQ_RCV_TYPE_EAGER)
-                       ipath_cdbg(PKT, "typ %x, opcode %x (eager, "
-                                  "qp=%x), len %x; ignored\n",
-                                  etype, bthbytes[0], qp, tlen);
                else if (etype == RCVHQ_RCV_TYPE_EXPECTED)
                        ipath_dbg("Bug: Expected TID, opcode %x; ignored\n",
-                                 be32_to_cpu(hdr->bth[0]) & 0xff);
+                                 be32_to_cpu(hdr->bth[0]) >> 24);
                else {
                        /*
                         * error packet, type of error unknown.
                         * Probably type 3, but we don't know, so don't
                         * even try to print the opcode, etc.
+                        * Usually caused by a "bad packet", that has no
+                        * BTH, when the LRH says it should.
                         */
-                       ipath_dbg("Error Pkt, but no eflags! egrbuf %x, "
-                                 "len %x\nhdrq@%lx;hdrq+%x rhf: %llx; "
-                                 "hdr %llx %llx %llx %llx %llx\n",
-                                 etail, tlen, (unsigned long) rc, l,
-                                 (unsigned long long) rc[0],
-                                 (unsigned long long) rc[1],
-                                 (unsigned long long) rc[2],
-                                 (unsigned long long) rc[3],
-                                 (unsigned long long) rc[4],
-                                 (unsigned long long) rc[5]);
+                       ipath_cdbg(ERRPKT, "Error Pkt, but no eflags! egrbuf"
+                                 " %x, len %x hdrq+%x rhf: %Lx\n",
+                                 etail, tlen, l,
+                                 le64_to_cpu(*(__le64 *) rhf_addr));
+                       if (ipath_debug & __IPATH_ERRPKTDBG) {
+                               u32 j, *d, dw = rsize-2;
+                               if (rsize > (tlen>>2))
+                                       dw = tlen>>2;
+                               d = (u32 *)hdr;
+                               printk(KERN_DEBUG "EPkt rcvhdr(%x dw):\n",
+                                       dw);
+                               for (j = 0; j < dw; j++)
+                                       printk(KERN_DEBUG "%8x%s", d[j],
+                                               (j%8) == 7 ? "\n" : " ");
+                               printk(KERN_DEBUG ".\n");
+                       }
                }
                l += rsize;
                if (l >= maxcnt)
                        l = 0;
-               if (etype != RCVHQ_RCV_TYPE_EXPECTED)
-                   updegr = 1;
+               rhf_addr = (__le32 *) pd->port_rcvhdrq +
+                       l + dd->ipath_rhf_offset;
+               if (dd->ipath_flags & IPATH_NODMA_RTAIL) {
+                       u32 seq = ipath_hdrget_seq(rhf_addr);
+
+                       if (++pd->port_seq_cnt > 13)
+                               pd->port_seq_cnt = 1;
+                       if (seq != pd->port_seq_cnt)
+                               last = 1;
+               } else if (l == hdrqtail)
+                       last = 1;
                /*
                 * update head regs on last packet, and every 16 packets.
                 * Reduce bus traffic, while still trying to prevent
                 * rcvhdrq overflows, for when the queue is nearly full
                 */
-               if (l == hdrqtail || (i && !(i&0xf))) {
-                       u64 lval;
-                       if (l == hdrqtail)
-                               /* request IBA6120 interrupt only on last */
-                               lval = dd->ipath_rhdrhead_intr_off | l;
-                       else
-                               lval = l;
-                       (void)ipath_write_ureg(dd, ur_rcvhdrhead, lval, 0);
+               if (last || !(i & 0xf)) {
+                       u64 lval = l;
+
+                       /* request IBA6120 and 7220 interrupt only on last */
+                       if (last)
+                               lval |= dd->ipath_rhdrhead_intr_off;
+                       ipath_write_ureg(dd, ur_rcvhdrhead, lval,
+                               pd->port_port);
                        if (updegr) {
-                               (void)ipath_write_ureg(dd, ur_rcvegrindexhead,
-                                                      etail, 0);
+                               ipath_write_ureg(dd, ur_rcvegrindexhead,
+                                                etail, pd->port_port);
                                updegr = 0;
                        }
                }
        }
 
-       if (!dd->ipath_rhdrhead_intr_off && !reloop) {
+       if (!dd->ipath_rhdrhead_intr_off && !reloop &&
+           !(dd->ipath_flags & IPATH_NODMA_RTAIL)) {
                /* IBA6110 workaround; we can have a race clearing chip
                 * interrupt with another interrupt about to be delivered,
                 * and can clear it before it is delivered on the GPIO
@@ -1301,7 +1326,6 @@ static void ipath_update_pio_bufs(struct ipath_devdata *dd)
         * happens when all buffers are in use, so only cpu overhead, not
         * latency or bandwidth is affected.
         */
-#define _IPATH_ALL_CHECKBITS 0x5555555555555555ULL
        if (!dd->ipath_pioavailregs_dma) {
                ipath_dbg("Update shadow pioavail, but regs_dma NULL!\n");
                return;
@@ -1346,7 +1370,7 @@ static void ipath_update_pio_bufs(struct ipath_devdata *dd)
                        piov = le64_to_cpu(dd->ipath_pioavailregs_dma[i ^ 1]);
                else
                        piov = le64_to_cpu(dd->ipath_pioavailregs_dma[i]);
-               pchg = _IPATH_ALL_CHECKBITS &
+               pchg = dd->ipath_pioavailkernel[i] &
                        ~(dd->ipath_pioavailshadow[i] ^ piov);
                pchbusy = pchg << INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT;
                if (pchg && (pchbusy & dd->ipath_pioavailshadow[i])) {
@@ -1397,27 +1421,63 @@ int ipath_setrcvhdrsize(struct ipath_devdata *dd, unsigned rhdrsize)
        return ret;
 }
 
-/**
- * ipath_getpiobuf - find an available pio buffer
- * @dd: the infinipath device
- * @pbufnum: the buffer number is placed here
+/*
+ * debugging code and stats updates if no pio buffers available.
+ */
+static noinline void no_pio_bufs(struct ipath_devdata *dd)
+{
+       unsigned long *shadow = dd->ipath_pioavailshadow;
+       __le64 *dma = (__le64 *)dd->ipath_pioavailregs_dma;
+
+       dd->ipath_upd_pio_shadow = 1;
+
+       /*
+        * not atomic, but if we lose a stat count in a while, that's OK
+        */
+       ipath_stats.sps_nopiobufs++;
+       if (!(++dd->ipath_consec_nopiobuf % 100000)) {
+               ipath_dbg("%u pio sends with no bufavail; dmacopy: "
+                       "%llx %llx %llx %llx; shadow:  %lx %lx %lx %lx\n",
+                       dd->ipath_consec_nopiobuf,
+                       (unsigned long long) le64_to_cpu(dma[0]),
+                       (unsigned long long) le64_to_cpu(dma[1]),
+                       (unsigned long long) le64_to_cpu(dma[2]),
+                       (unsigned long long) le64_to_cpu(dma[3]),
+                       shadow[0], shadow[1], shadow[2], shadow[3]);
+               /*
+                * 4 buffers per byte, 4 registers above, cover rest
+                * below
+                */
+               if ((dd->ipath_piobcnt2k + dd->ipath_piobcnt4k) >
+                   (sizeof(shadow[0]) * 4 * 4))
+                       ipath_dbg("2nd group: dmacopy: %llx %llx "
+                                 "%llx %llx; shadow: %lx %lx %lx %lx\n",
+                                 (unsigned long long)le64_to_cpu(dma[4]),
+                                 (unsigned long long)le64_to_cpu(dma[5]),
+                                 (unsigned long long)le64_to_cpu(dma[6]),
+                                 (unsigned long long)le64_to_cpu(dma[7]),
+                                 shadow[4], shadow[5], shadow[6],
+                                 shadow[7]);
+       }
+}
+
+/*
+ * common code for normal driver pio buffer allocation, and reserved
+ * allocation.
  *
  * do appropriate marking as busy, etc.
  * returns buffer number if one found (>=0), negative number is error.
- * Used by ipath_layer_send
  */
-u32 __iomem *ipath_getpiobuf(struct ipath_devdata *dd, u32 * pbufnum)
+static u32 __iomem *ipath_getpiobuf_range(struct ipath_devdata *dd,
+       u32 *pbufnum, u32 first, u32 last, u32 firsti)
 {
-       int i, j, starti, updated = 0;
-       unsigned piobcnt, iter;
+       int i, j, updated = 0;
+       unsigned piobcnt;
        unsigned long flags;
        unsigned long *shadow = dd->ipath_pioavailshadow;
        u32 __iomem *buf;
 
-       piobcnt = (unsigned)(dd->ipath_piobcnt2k
-                            + dd->ipath_piobcnt4k);
-       starti = dd->ipath_lastport_piobuf;
-       iter = piobcnt - starti;
+       piobcnt = last - first;
        if (dd->ipath_upd_pio_shadow) {
                /*
                 * Minor optimization.  If we had no buffers on last call,
@@ -1425,12 +1485,10 @@ u32 __iomem *ipath_getpiobuf(struct ipath_devdata *dd, u32 * pbufnum)
                 * if no buffers were updated, to be paranoid
                 */
                ipath_update_pio_bufs(dd);
-               /* we scanned here, don't do it at end of scan */
-               updated = 1;
-               i = starti;
+               updated++;
+               i = first;
        } else
-               i = dd->ipath_lastpioindex;
-
+               i = firsti;
 rescan:
        /*
         * while test_and_set_bit() is atomic, we do that and then the
@@ -1438,103 +1496,140 @@ rescan:
         * of the remaining armlaunch errors.
         */
        spin_lock_irqsave(&ipath_pioavail_lock, flags);
-       for (j = 0; j < iter; j++, i++) {
-               if (i >= piobcnt)
-                       i = starti;
-               /*
-                * To avoid bus lock overhead, we first find a candidate
-                * buffer, then do the test and set, and continue if that
-                * fails.
-                */
-               if (test_bit((2 * i) + 1, shadow) ||
-                   test_and_set_bit((2 * i) + 1, shadow))
+       for (j = 0; j < piobcnt; j++, i++) {
+               if (i >= last)
+                       i = first;
+               if (__test_and_set_bit((2 * i) + 1, shadow))
                        continue;
                /* flip generation bit */
-               change_bit(2 * i, shadow);
+               __change_bit(2 * i, shadow);
                break;
        }
        spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
 
-       if (j == iter) {
-               volatile __le64 *dma = dd->ipath_pioavailregs_dma;
-
-               /*
-                * first time through; shadow exhausted, but may be real
-                * buffers available, so go see; if any updated, rescan
-                * (once)
-                */
+       if (j == piobcnt) {
                if (!updated) {
+                       /*
+                        * first time through; shadow exhausted, but may be
+                        * buffers available, try an update and then rescan.
+                        */
                        ipath_update_pio_bufs(dd);
-                       updated = 1;
-                       i = starti;
+                       updated++;
+                       i = first;
                        goto rescan;
-               }
-               dd->ipath_upd_pio_shadow = 1;
-               /*
-                * not atomic, but if we lose one once in a while, that's OK
-                */
-               ipath_stats.sps_nopiobufs++;
-               if (!(++dd->ipath_consec_nopiobuf % 100000)) {
-                       ipath_dbg(
-                               "%u pio sends with no bufavail; dmacopy: "
-                               "%llx %llx %llx %llx; shadow:  "
-                               "%lx %lx %lx %lx\n",
-                               dd->ipath_consec_nopiobuf,
-                               (unsigned long long) le64_to_cpu(dma[0]),
-                               (unsigned long long) le64_to_cpu(dma[1]),
-                               (unsigned long long) le64_to_cpu(dma[2]),
-                               (unsigned long long) le64_to_cpu(dma[3]),
-                               shadow[0], shadow[1], shadow[2],
-                               shadow[3]);
+               } else if (updated == 1 && piobcnt <=
+                       ((dd->ipath_sendctrl
+                       >> INFINIPATH_S_UPDTHRESH_SHIFT) &
+                       INFINIPATH_S_UPDTHRESH_MASK)) {
                        /*
-                        * 4 buffers per byte, 4 registers above, cover rest
-                        * below
+                        * for chips supporting and using the update
+                        * threshold we need to force an update of the
+                        * in-memory copy if the count is less than the
+                        * thershold, then check one more time.
                         */
-                       if ((dd->ipath_piobcnt2k + dd->ipath_piobcnt4k) >
-                           (sizeof(shadow[0]) * 4 * 4))
-                               ipath_dbg("2nd group: dmacopy: %llx %llx "
-                                         "%llx %llx; shadow: %lx %lx "
-                                         "%lx %lx\n",
-                                         (unsigned long long)
-                                         le64_to_cpu(dma[4]),
-                                         (unsigned long long)
-                                         le64_to_cpu(dma[5]),
-                                         (unsigned long long)
-                                         le64_to_cpu(dma[6]),
-                                         (unsigned long long)
-                                         le64_to_cpu(dma[7]),
-                                         shadow[4], shadow[5],
-                                         shadow[6], shadow[7]);
+                       ipath_force_pio_avail_update(dd);
+                       ipath_update_pio_bufs(dd);
+                       updated++;
+                       i = first;
+                       goto rescan;
                }
+
+               no_pio_bufs(dd);
                buf = NULL;
-               goto bail;
+       } else {
+               if (i < dd->ipath_piobcnt2k)
+                       buf = (u32 __iomem *) (dd->ipath_pio2kbase +
+                                              i * dd->ipath_palign);
+               else
+                       buf = (u32 __iomem *)
+                               (dd->ipath_pio4kbase +
+                                (i - dd->ipath_piobcnt2k) * dd->ipath_4kalign);
+               if (pbufnum)
+                       *pbufnum = i;
        }
 
-       /*
-        * set next starting place.  Since it's just an optimization,
-        * it doesn't matter who wins on this, so no locking
-        */
-       dd->ipath_lastpioindex = i + 1;
-       if (dd->ipath_upd_pio_shadow)
-               dd->ipath_upd_pio_shadow = 0;
-       if (dd->ipath_consec_nopiobuf)
-               dd->ipath_consec_nopiobuf = 0;
-       if (i < dd->ipath_piobcnt2k)
-               buf = (u32 __iomem *) (dd->ipath_pio2kbase +
-                                      i * dd->ipath_palign);
-       else
-               buf = (u32 __iomem *)
-                       (dd->ipath_pio4kbase +
-                        (i - dd->ipath_piobcnt2k) * dd->ipath_4kalign);
-       ipath_cdbg(VERBOSE, "Return piobuf%u %uk @ %p\n",
-                  i, (i < dd->ipath_piobcnt2k) ? 2 : 4, buf);
-       if (pbufnum)
-               *pbufnum = i;
+       return buf;
+}
 
-bail:
+/**
+ * ipath_getpiobuf - find an available pio buffer
+ * @dd: the infinipath device
+ * @plen: the size of the PIO buffer needed in 32-bit words
+ * @pbufnum: the buffer number is placed here
+ */
+u32 __iomem *ipath_getpiobuf(struct ipath_devdata *dd, u32 plen, u32 *pbufnum)
+{
+       u32 __iomem *buf;
+       u32 pnum, nbufs;
+       u32 first, lasti;
+
+       if (plen + 1 >= IPATH_SMALLBUF_DWORDS) {
+               first = dd->ipath_piobcnt2k;
+               lasti = dd->ipath_lastpioindexl;
+       } else {
+               first = 0;
+               lasti = dd->ipath_lastpioindex;
+       }
+       nbufs = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
+       buf = ipath_getpiobuf_range(dd, &pnum, first, nbufs, lasti);
+
+       if (buf) {
+               /*
+                * Set next starting place.  It's just an optimization,
+                * it doesn't matter who wins on this, so no locking
+                */
+               if (plen + 1 >= IPATH_SMALLBUF_DWORDS)
+                       dd->ipath_lastpioindexl = pnum + 1;
+               else
+                       dd->ipath_lastpioindex = pnum + 1;
+               if (dd->ipath_upd_pio_shadow)
+                       dd->ipath_upd_pio_shadow = 0;
+               if (dd->ipath_consec_nopiobuf)
+                       dd->ipath_consec_nopiobuf = 0;
+               ipath_cdbg(VERBOSE, "Return piobuf%u %uk @ %p\n",
+                          pnum, (pnum < dd->ipath_piobcnt2k) ? 2 : 4, buf);
+               if (pbufnum)
+                       *pbufnum = pnum;
+
+       }
        return buf;
 }
 
+/**
+ * ipath_chg_pioavailkernel - change which send buffers are available for kernel
+ * @dd: the infinipath device
+ * @start: the starting send buffer number
+ * @len: the number of send buffers
+ * @avail: true if the buffers are available for kernel use, false otherwise
+ */
+void ipath_chg_pioavailkernel(struct ipath_devdata *dd, unsigned start,
+                             unsigned len, int avail)
+{
+       unsigned long flags;
+       unsigned end;
+
+       /* There are two bits per send buffer (busy and generation) */
+       start *= 2;
+       len *= 2;
+       end = start + len;
+
+       /* Set or clear the generation bits. */
+       spin_lock_irqsave(&ipath_pioavail_lock, flags);
+       while (start < end) {
+               if (avail) {
+                       __clear_bit(start + INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT,
+                               dd->ipath_pioavailshadow);
+                       __set_bit(start, dd->ipath_pioavailkernel);
+               } else {
+                       __set_bit(start + INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT,
+                               dd->ipath_pioavailshadow);
+                       __clear_bit(start, dd->ipath_pioavailkernel);
+               }
+               start += 2;
+       }
+       spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
+}
+
 /**
  * ipath_create_rcvhdrq - create a receive header queue
  * @dd: the infinipath device
@@ -1566,19 +1661,27 @@ int ipath_create_rcvhdrq(struct ipath_devdata *dd,
                        ret = -ENOMEM;
                        goto bail;
                }
-               pd->port_rcvhdrtail_kvaddr = dma_alloc_coherent(
-                       &dd->pcidev->dev, PAGE_SIZE, &phys_hdrqtail, GFP_KERNEL);
-               if (!pd->port_rcvhdrtail_kvaddr) {
-                       ipath_dev_err(dd, "attempt to allocate 1 page "
-                                     "for port %u rcvhdrqtailaddr failed\n",
-                                     pd->port_port);
-                       ret = -ENOMEM;
-                       dma_free_coherent(&dd->pcidev->dev, amt,
-                                         pd->port_rcvhdrq, pd->port_rcvhdrq_phys);
-                       pd->port_rcvhdrq = NULL;
-                       goto bail;
+
+               if (!(dd->ipath_flags & IPATH_NODMA_RTAIL)) {
+                       pd->port_rcvhdrtail_kvaddr = dma_alloc_coherent(
+                               &dd->pcidev->dev, PAGE_SIZE, &phys_hdrqtail,
+                               GFP_KERNEL);
+                       if (!pd->port_rcvhdrtail_kvaddr) {
+                               ipath_dev_err(dd, "attempt to allocate 1 page "
+                                       "for port %u rcvhdrqtailaddr "
+                                       "failed\n", pd->port_port);
+                               ret = -ENOMEM;
+                               dma_free_coherent(&dd->pcidev->dev, amt,
+                                       pd->port_rcvhdrq,
+                                       pd->port_rcvhdrq_phys);
+                               pd->port_rcvhdrq = NULL;
+                               goto bail;
+                       }
+                       pd->port_rcvhdrqtailaddr_phys = phys_hdrqtail;
+                       ipath_cdbg(VERBOSE, "port %d hdrtailaddr, %llx "
+                                  "physical\n", pd->port_port,
+                                  (unsigned long long) phys_hdrqtail);
                }
-               pd->port_rcvhdrqtailaddr_phys = phys_hdrqtail;
 
                pd->port_rcvhdrq_size = amt;
 
@@ -1588,10 +1691,6 @@ int ipath_create_rcvhdrq(struct ipath_devdata *dd,
                           (unsigned long) pd->port_rcvhdrq_phys,
                           (unsigned long) pd->port_rcvhdrq_size,
                           pd->port_port);
-
-               ipath_cdbg(VERBOSE, "port %d hdrtailaddr, %llx physical\n",
-                          pd->port_port,
-                          (unsigned long long) phys_hdrqtail);
        }
        else
                ipath_cdbg(VERBOSE, "reuse port %d rcvhdrq @%p %llx phys; "
@@ -1615,7 +1714,6 @@ int ipath_create_rcvhdrq(struct ipath_devdata *dd,
        ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr,
                              pd->port_port, pd->port_rcvhdrq_phys);
 
-       ret = 0;
 bail:
        return ret;
 }
@@ -1632,8 +1730,15 @@ bail:
  */
 void ipath_cancel_sends(struct ipath_devdata *dd, int restore_sendctrl)
 {
+       if (dd->ipath_flags & IPATH_IB_AUTONEG_INPROG) {
+               ipath_cdbg(VERBOSE, "Ignore while in autonegotiation\n");
+               goto bail;
+       }
        ipath_dbg("Cancelling all in-progress send buffers\n");
-       dd->ipath_lastcancel = jiffies+HZ/2; /* skip armlaunch errs a bit */
+
+       /* skip armlaunch errs for a while */
+       dd->ipath_lastcancel = jiffies + HZ / 2;
+
        /*
         * the abort bit is auto-clearing.  We read scratch to be sure
         * that cancels and the abort have taken effect in the chip.
@@ -1649,35 +1754,75 @@ void ipath_cancel_sends(struct ipath_devdata *dd, int restore_sendctrl)
 
        /* and again, be sure all have hit the chip */
        ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+bail:;
 }
 
+/*
+ * Force an update of in-memory copy of the pioavail registers, when
+ * needed for any of a variety of reasons.  We read the scratch register
+ * to make it highly likely that the update will have happened by the
+ * time we return.  If already off (as in cancel_sends above), this
+ * routine is a nop, on the assumption that the caller will "do the
+ * right thing".
+ */
+void ipath_force_pio_avail_update(struct ipath_devdata *dd)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+       if (dd->ipath_sendctrl & INFINIPATH_S_PIOBUFAVAILUPD) {
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+                       dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);
+               ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+               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);
+}
 
-static void ipath_set_ib_lstate(struct ipath_devdata *dd, int which)
+static void ipath_set_ib_lstate(struct ipath_devdata *dd, int linkcmd,
+                               int linitcmd)
 {
+       u64 mod_wd;
        static const char *what[4] = {
                [0] = "NOP",
                [INFINIPATH_IBCC_LINKCMD_DOWN] = "DOWN",
                [INFINIPATH_IBCC_LINKCMD_ARMED] = "ARMED",
                [INFINIPATH_IBCC_LINKCMD_ACTIVE] = "ACTIVE"
        };
-       int linkcmd = (which >> INFINIPATH_IBCC_LINKCMD_SHIFT) &
-                       INFINIPATH_IBCC_LINKCMD_MASK;
-
-       ipath_cdbg(VERBOSE, "Trying to move unit %u to %s, current ltstate "
-                  "is %s\n", dd->ipath_unit,
-                  what[linkcmd],
-                  ipath_ibcstatus_str[
-                          (ipath_read_kreg64
-                           (dd, dd->ipath_kregs->kr_ibcstatus) >>
-                           INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT) &
-                          INFINIPATH_IBCS_LINKTRAININGSTATE_MASK]);
-       /* flush all queued sends when going to DOWN to be sure that
-        * they don't block MAD packets */
-       if (linkcmd == INFINIPATH_IBCC_LINKCMD_DOWN)
-               ipath_cancel_sends(dd, 1);
+
+       if (linitcmd == INFINIPATH_IBCC_LINKINITCMD_DISABLE) {
+               /*
+                * If we are told to disable, note that so link-recovery
+                * code does not attempt to bring us back up.
+                */
+               preempt_disable();
+               dd->ipath_flags |= IPATH_IB_LINK_DISABLED;
+               preempt_enable();
+       } else if (linitcmd) {
+               /*
+                * Any other linkinitcmd will lead to LINKDOWN and then
+                * to INIT (if all is well), so clear flag to let
+                * link-recovery code attempt to bring us back up.
+                */
+               preempt_disable();
+               dd->ipath_flags &= ~IPATH_IB_LINK_DISABLED;
+               preempt_enable();
+       }
+
+       mod_wd = (linkcmd << dd->ibcc_lc_shift) |
+               (linitcmd << INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+       ipath_cdbg(VERBOSE,
+               "Moving unit %u to %s (initcmd=0x%x), current ltstate is %s\n",
+               dd->ipath_unit, what[linkcmd], linitcmd,
+               ipath_ibcstatus_str[ipath_ib_linktrstate(dd,
+                       ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus))]);
 
        ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
-                        dd->ipath_ibcctrl | which);
+                        dd->ipath_ibcctrl | mod_wd);
+       /* read from chip so write is flushed */
+       (void) ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
 }
 
 int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
@@ -1687,30 +1832,28 @@ int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
 
        switch (newstate) {
        case IPATH_IB_LINKDOWN_ONLY:
-               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_DOWN <<
-                                   INFINIPATH_IBCC_LINKCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_DOWN, 0);
                /* don't wait */
                ret = 0;
                goto bail;
 
        case IPATH_IB_LINKDOWN:
-               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKINITCMD_POLL <<
-                                   INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_DOWN,
+                                       INFINIPATH_IBCC_LINKINITCMD_POLL);
                /* don't wait */
                ret = 0;
                goto bail;
 
        case IPATH_IB_LINKDOWN_SLEEP:
-               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKINITCMD_SLEEP <<
-                                   INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_DOWN,
+                                       INFINIPATH_IBCC_LINKINITCMD_SLEEP);
                /* don't wait */
                ret = 0;
                goto bail;
 
        case IPATH_IB_LINKDOWN_DISABLE:
-               ipath_set_ib_lstate(dd,
-                                   INFINIPATH_IBCC_LINKINITCMD_DISABLE <<
-                                   INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_DOWN,
+                                       INFINIPATH_IBCC_LINKINITCMD_DISABLE);
                /* don't wait */
                ret = 0;
                goto bail;
@@ -1725,8 +1868,8 @@ int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
                        ret = -EINVAL;
                        goto bail;
                }
-               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_ARMED <<
-                                   INFINIPATH_IBCC_LINKCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_ARMED, 0);
+
                /*
                 * Since the port can transition to ACTIVE by receiving
                 * a non VL 15 packet, wait for either state.
@@ -1743,8 +1886,7 @@ int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
                        ret = -EINVAL;
                        goto bail;
                }
-               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_ACTIVE <<
-                                   INFINIPATH_IBCC_LINKCMD_SHIFT);
+               ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKCMD_ACTIVE, 0);
                lstate = IPATH_LINKACTIVE;
                break;
 
@@ -1753,16 +1895,41 @@ int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
                dd->ipath_ibcctrl |= INFINIPATH_IBCC_LOOPBACK;
                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
                                 dd->ipath_ibcctrl);
+
+               /* turn heartbeat off, as it causes loopback to fail */
+               dd->ipath_f_set_ib_cfg(dd, IPATH_IB_CFG_HRTBT,
+                                      IPATH_IB_HRTBT_OFF);
+               /* don't wait */
                ret = 0;
-               goto bail; // no state change to wait for
+               goto bail;
 
        case IPATH_IB_LINK_EXTERNAL:
-               dev_info(&dd->pcidev->dev, "Disabling IB local loopback (normal)\n");
+               dev_info(&dd->pcidev->dev,
+                       "Disabling IB local loopback (normal)\n");
+               dd->ipath_f_set_ib_cfg(dd, IPATH_IB_CFG_HRTBT,
+                                      IPATH_IB_HRTBT_ON);
                dd->ipath_ibcctrl &= ~INFINIPATH_IBCC_LOOPBACK;
                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
                                 dd->ipath_ibcctrl);
+               /* don't wait */
                ret = 0;
-               goto bail; // no state change to wait for
+               goto bail;
+
+       /*
+        * Heartbeat can be explicitly enabled by the user via
+        * "hrtbt_enable" "file", and if disabled, trying to enable here
+        * will have no effect.  Implicit changes (heartbeat off when
+        * loopback on, and vice versa) are included to ease testing.
+        */
+       case IPATH_IB_LINK_HRTBT:
+               ret = dd->ipath_f_set_ib_cfg(dd, IPATH_IB_CFG_HRTBT,
+                       IPATH_IB_HRTBT_ON);
+               goto bail;
+
+       case IPATH_IB_LINK_NO_HRTBT:
+               ret = dd->ipath_f_set_ib_cfg(dd, IPATH_IB_CFG_HRTBT,
+                       IPATH_IB_HRTBT_OFF);
+               goto bail;
 
        default:
                ipath_dbg("Invalid linkstate 0x%x requested\n", newstate);
@@ -1800,7 +1967,7 @@ int ipath_set_mtu(struct ipath_devdata *dd, u16 arg)
         * piosize).  We check that it's one of the valid IB sizes.
         */
        if (arg != 256 && arg != 512 && arg != 1024 && arg != 2048 &&
-           arg != 4096) {
+           (arg != 4096 || !ipath_mtu4096)) {
                ipath_dbg("Trying to set invalid mtu %u, failing\n", arg);
                ret = -EINVAL;
                goto bail;
@@ -1816,6 +1983,8 @@ int ipath_set_mtu(struct ipath_devdata *dd, u16 arg)
        if (arg >= (piosize - IPATH_PIO_MAXIBHDR)) {
                /* Only if it's not the initial value (or reset to it) */
                if (piosize != dd->ipath_init_ibmaxlen) {
+                       if (arg > piosize && arg <= dd->ipath_init_ibmaxlen)
+                               piosize = dd->ipath_init_ibmaxlen;
                        dd->ipath_ibmaxlen = piosize;
                        changed = 1;
                }
@@ -1829,24 +1998,17 @@ int ipath_set_mtu(struct ipath_devdata *dd, u16 arg)
        }
 
        if (changed) {
+               u64 ibc = dd->ipath_ibcctrl, ibdw;
                /*
-                * set the IBC maxpktlength to the size of our pio
-                * buffers in words
+                * update our housekeeping variables, and set IBC max
+                * size, same as init code; max IBC is max we allow in
+                * buffer, less the qword pbc, plus 1 for ICRC, in dwords
                 */
-               u64 ibc = dd->ipath_ibcctrl;
+               dd->ipath_ibmaxlen = piosize - 2 * sizeof(u32);
+               ibdw = (dd->ipath_ibmaxlen >> 2) + 1;
                ibc &= ~(INFINIPATH_IBCC_MAXPKTLEN_MASK <<
-                        INFINIPATH_IBCC_MAXPKTLEN_SHIFT);
-
-               piosize = piosize - 2 * sizeof(u32);    /* ignore pbc */
-               dd->ipath_ibmaxlen = piosize;
-               piosize /= sizeof(u32); /* in words */
-               /*
-                * for ICRC, which we only send in diag test pkt mode, and
-                * we don't need to worry about that for mtu
-                */
-               piosize += 1;
-
-               ibc |= piosize << INFINIPATH_IBCC_MAXPKTLEN_SHIFT;
+                        dd->ibcc_mpl_shift);
+               ibc |= ibdw << dd->ibcc_mpl_shift;
                dd->ipath_ibcctrl = ibc;
                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
                                 dd->ipath_ibcctrl);
@@ -1859,11 +2021,16 @@ bail:
        return ret;
 }
 
-int ipath_set_lid(struct ipath_devdata *dd, u32 arg, u8 lmc)
+int ipath_set_lid(struct ipath_devdata *dd, u32 lid, u8 lmc)
 {
-       dd->ipath_lid = arg;
+       dd->ipath_lid = lid;
        dd->ipath_lmc = lmc;
 
+       dd->ipath_f_set_ib_cfg(dd, IPATH_IB_CFG_LIDLMC, lid |
+               (~((1U << lmc) - 1)) << 16);
+
+       dev_info(&dd->pcidev->dev, "We got a lid: 0x%x\n", lid);
+
        return 0;
 }
 
@@ -1926,9 +2093,8 @@ static void ipath_run_led_override(unsigned long opaque)
         */
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
        ltstate = (val >> INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT) &
-                 INFINIPATH_IBCS_LINKTRAININGSTATE_MASK;
-       lstate = (val >> INFINIPATH_IBCS_LINKSTATE_SHIFT) &
-                INFINIPATH_IBCS_LINKSTATE_MASK;
+                 dd->ibcs_lts_mask;
+       lstate = (val >> dd->ibcs_ls_shift) & INFINIPATH_IBCS_LINKSTATE_MASK;
 
        dd->ipath_f_setextled(dd, lstate, ltstate);
        mod_timer(&dd->ipath_led_override_timer, jiffies + timeoff);
@@ -1969,9 +2135,8 @@ void ipath_set_led_override(struct ipath_devdata *dd, unsigned int val)
                dd->ipath_led_override_timer.data = (unsigned long) dd;
                dd->ipath_led_override_timer.expires = jiffies + 1;
                add_timer(&dd->ipath_led_override_timer);
-       } else {
+       } else
                atomic_dec(&dd->ipath_led_override_timer_active);
-       }
 }
 
 /**
@@ -1989,6 +2154,8 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
 
        ipath_dbg("Shutting down the device\n");
 
+       ipath_hol_up(dd); /* make sure user processes aren't suspended */
+
        dd->ipath_flags |= IPATH_LINKUNK;
        dd->ipath_flags &= ~(IPATH_INITTED | IPATH_LINKDOWN |
                             IPATH_LINKINIT | IPATH_LINKARMED |
@@ -2020,8 +2187,7 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
         */
        udelay(5);
 
-       ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKINITCMD_DISABLE <<
-                           INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+       ipath_set_ib_lstate(dd, 0, INFINIPATH_IBCC_LINKINITCMD_DISABLE);
        ipath_cancel_sends(dd, 0);
 
        signal_ib_event(dd, IB_EVENT_PORT_ERR);
@@ -2038,10 +2204,16 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
         */
        dd->ipath_f_quiet_serdes(dd);
 
+       /* stop all the timers that might still be running */
+       del_timer_sync(&dd->ipath_hol_timer);
        if (dd->ipath_stats_timer_active) {
                del_timer_sync(&dd->ipath_stats_timer);
                dd->ipath_stats_timer_active = 0;
        }
+       if (dd->ipath_intrchk_timer.data) {
+               del_timer_sync(&dd->ipath_intrchk_timer);
+               dd->ipath_intrchk_timer.data = 0;
+       }
 
        /*
         * clear all interrupts and errors, so that the next time the driver
@@ -2115,13 +2287,13 @@ void ipath_free_pddata(struct ipath_devdata *dd, struct ipath_portdata *pd)
                ipath_cdbg(VERBOSE, "free closed port %d "
                           "ipath_port0_skbinfo @ %p\n", pd->port_port,
                           skbinfo);
-               for (e = 0; e < dd->ipath_rcvegrcnt; e++)
-               if (skbinfo[e].skb) {
-                       pci_unmap_single(dd->pcidev, skbinfo[e].phys,
-                                        dd->ipath_ibmaxlen,
-                                        PCI_DMA_FROMDEVICE);
-                       dev_kfree_skb(skbinfo[e].skb);
-               }
+               for (e = 0; e < dd->ipath_p0_rcvegrcnt; e++)
+                       if (skbinfo[e].skb) {
+                               pci_unmap_single(dd->pcidev, skbinfo[e].phys,
+                                                dd->ipath_ibmaxlen,
+                                                PCI_DMA_FROMDEVICE);
+                               dev_kfree_skb(skbinfo[e].skb);
+                       }
                vfree(skbinfo);
        }
        kfree(pd->port_tid_pg_list);
@@ -2144,6 +2316,7 @@ static int __init infinipath_init(void)
         */
        idr_init(&unit_table);
        if (!idr_pre_get(&unit_table, GFP_KERNEL)) {
+               printk(KERN_ERR IPATH_DRV_NAME ": idr_pre_get() failed\n");
                ret = -ENOMEM;
                goto bail;
        }
@@ -2253,13 +2426,121 @@ bail:
        return ret;
 }
 
+/*
+ * send a signal to all the processes that have the driver open
+ * through the normal interfaces (i.e., everything other than diags
+ * interface).  Returns number of signalled processes.
+ */
+static int ipath_signal_procs(struct ipath_devdata *dd, int sig)
+{
+       int i, sub, any = 0;
+       pid_t pid;
+
+       if (!dd->ipath_pd)
+               return 0;
+       for (i = 1; i < dd->ipath_cfgports; i++) {
+               if (!dd->ipath_pd[i] || !dd->ipath_pd[i]->port_cnt ||
+                   !dd->ipath_pd[i]->port_pid)
+                       continue;
+               pid = dd->ipath_pd[i]->port_pid;
+               dev_info(&dd->pcidev->dev, "context %d in use "
+                         "(PID %u), sending signal %d\n",
+                         i, pid, sig);
+               kill_proc(pid, sig, 1);
+               any++;
+               for (sub = 0; sub < INFINIPATH_MAX_SUBPORT; sub++) {
+                       pid = dd->ipath_pd[i]->port_subpid[sub];
+                       if (!pid)
+                               continue;
+                       dev_info(&dd->pcidev->dev, "sub-context "
+                               "%d:%d in use (PID %u), sending "
+                               "signal %d\n", i, sub, pid, sig);
+                       kill_proc(pid, sig, 1);
+                       any++;
+               }
+       }
+       return any;
+}
+
+static void ipath_hol_signal_down(struct ipath_devdata *dd)
+{
+       if (ipath_signal_procs(dd, SIGSTOP))
+               ipath_dbg("Stopped some processes\n");
+       ipath_cancel_sends(dd, 1);
+}
+
+
+static void ipath_hol_signal_up(struct ipath_devdata *dd)
+{
+       if (ipath_signal_procs(dd, SIGCONT))
+               ipath_dbg("Continued some processes\n");
+}
+
+/*
+ * link is down, stop any users processes, and flush pending sends
+ * to prevent HoL blocking, then start the HoL timer that
+ * periodically continues, then stop procs, so they can detect
+ * link down if they want, and do something about it.
+ * Timer may already be running, so use __mod_timer, not add_timer.
+ */
+void ipath_hol_down(struct ipath_devdata *dd)
+{
+       dd->ipath_hol_state = IPATH_HOL_DOWN;
+       ipath_hol_signal_down(dd);
+       dd->ipath_hol_next = IPATH_HOL_DOWNCONT;
+       dd->ipath_hol_timer.expires = jiffies +
+               msecs_to_jiffies(ipath_hol_timeout_ms);
+       __mod_timer(&dd->ipath_hol_timer, dd->ipath_hol_timer.expires);
+}
+
+/*
+ * link is up, continue any user processes, and ensure timer
+ * is a nop, if running.  Let timer keep running, if set; it
+ * will nop when it sees the link is up
+ */
+void ipath_hol_up(struct ipath_devdata *dd)
+{
+       ipath_hol_signal_up(dd);
+       dd->ipath_hol_state = IPATH_HOL_UP;
+}
+
+/*
+ * toggle the running/not running state of user proceses
+ * to prevent HoL blocking on chip resources, but still allow
+ * user processes to do link down special case handling.
+ * Should only be called via the timer
+ */
+void ipath_hol_event(unsigned long opaque)
+{
+       struct ipath_devdata *dd = (struct ipath_devdata *)opaque;
+
+       if (dd->ipath_hol_next == IPATH_HOL_DOWNSTOP
+               && dd->ipath_hol_state != IPATH_HOL_UP) {
+               dd->ipath_hol_next = IPATH_HOL_DOWNCONT;
+               ipath_dbg("Stopping processes\n");
+               ipath_hol_signal_down(dd);
+       } else { /* may do "extra" if also in ipath_hol_up() */
+               dd->ipath_hol_next = IPATH_HOL_DOWNSTOP;
+               ipath_dbg("Continuing processes\n");
+               ipath_hol_signal_up(dd);
+       }
+       if (dd->ipath_hol_state == IPATH_HOL_UP)
+               ipath_dbg("link's up, don't resched timer\n");
+       else {
+               dd->ipath_hol_timer.expires = jiffies +
+                       msecs_to_jiffies(ipath_hol_timeout_ms);
+               __mod_timer(&dd->ipath_hol_timer,
+                       dd->ipath_hol_timer.expires);
+       }
+}
+
 int ipath_set_rx_pol_inv(struct ipath_devdata *dd, u8 new_pol_inv)
 {
        u64 val;
-       if ( new_pol_inv > INFINIPATH_XGXS_RX_POL_MASK ) {
+
+       if (new_pol_inv > INFINIPATH_XGXS_RX_POL_MASK)
                return -1;
-       }
-       if ( dd->ipath_rx_pol_inv != new_pol_inv ) {
+       if (dd->ipath_rx_pol_inv != new_pol_inv) {
                dd->ipath_rx_pol_inv = new_pol_inv;
                val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_xgxsconfig);
                val &= ~(INFINIPATH_XGXS_RX_POL_MASK <<