8 files changed, 224 insertions, 202 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index f81dd4acdc60..2036d38fac47 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -1428,6 +1428,40 @@ static void ipath_update_pio_bufs(struct ipath_devdata *dd)
         spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
 }
 
+/*
+ * used to force update of pioavailshadow if we can't get a pio buffer.
+ * Needed primarily due to exitting freeze mode after recovering
+ * from errors.  Done lazily, because it's safer (known to not
+ * be writing pio buffers).
+ */
+static void ipath_reset_availshadow(struct ipath_devdata *dd)
+{
+        int i, im;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ipath_pioavail_lock, flags);
+        for (i = 0; i < dd->ipath_pioavregs; i++) {
+                u64 val, oldval;
+                /* deal with 6110 chip bug on high register #s */
+                im = (i > 3 && (dd->ipath_flags & IPATH_SWAP_PIOBUFS)) ?
+                        i ^ 1 : i;
+                val = le64_to_cpu(dd->ipath_pioavailregs_dma[im]);
+                /*
+                 * busy out the buffers not in the kernel avail list,
+                 * without changing the generation bits.
+                 */
+                oldval = dd->ipath_pioavailshadow[i];
+                dd->ipath_pioavailshadow[i] = val |
+                        ((~dd->ipath_pioavailkernel[i] <<
+                        INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT) &
+                        0xaaaaaaaaaaaaaaaaULL); /* All BUSY bits in qword */
+                if (oldval != dd->ipath_pioavailshadow[i])
+                        ipath_dbg("shadow[%d] was %Lx, now %lx\n",
+                                i, oldval, dd->ipath_pioavailshadow[i]);
+        }
+        spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
+}
+
 /**
  * ipath_setrcvhdrsize - set the receive header size
  * @dd: the infinipath device
@@ -1482,9 +1516,12 @@ static noinline void no_pio_bufs(struct ipath_devdata *dd)
          */
         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",
+                ipath_force_pio_avail_update(dd); /* at start */
+                ipath_dbg("%u tries no piobufavail ts%lx; dmacopy: "
+                        "%llx %llx %llx %llx\n"
+                        "ipath  shadow:  %lx %lx %lx %lx\n",
                         dd->ipath_consec_nopiobuf,
+                        (unsigned long)get_cycles(),
                         (unsigned long long) le64_to_cpu(dma[0]),
                         (unsigned long long) le64_to_cpu(dma[1]),
                         (unsigned long long) le64_to_cpu(dma[2]),
@@ -1496,14 +1533,17 @@ static noinline void no_pio_bufs(struct ipath_devdata *dd)
                  */
                 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",
+                        ipath_dbg("2nd group: dmacopy: "
+                                  "%llx %llx %llx %llx\n"
+                                  "ipath  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]);
+                                  shadow[4], shadow[5], shadow[6], shadow[7]);
+
+                /* at end, so update likely happened */
+                ipath_reset_availshadow(dd);
         }
 }
 
@@ -1652,19 +1692,46 @@ void ipath_chg_pioavailkernel(struct ipath_devdata *dd, unsigned start,
                               unsigned len, int avail)
 {
         unsigned long flags;
-        unsigned end;
+        unsigned end, cnt = 0, next;
 
         /* There are two bits per send buffer (busy and generation) */
         start *= 2;
-        len *= 2;
-        end = start + len;
+        end = start + len * 2;
 
-        /* Set or clear the generation bits. */
         spin_lock_irqsave(&ipath_pioavail_lock, flags);
+        /* Set or clear the busy bit in the shadow. */
         while (start < end) {
                 if (avail) {
-                        __clear_bit(start + INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT,
-                                dd->ipath_pioavailshadow);
+                        unsigned long dma;
+                        int i, im;
+                        /*
+                         * the BUSY bit will never be set, because we disarm
+                         * the user buffers before we hand them back to the
+                         * kernel.  We do have to make sure the generation
+                         * bit is set correctly in shadow, since it could
+                         * have changed many times while allocated to user.
+                         * We can't use the bitmap functions on the full
+                         * dma array because it is always little-endian, so
+                         * we have to flip to host-order first.
+                         * BITS_PER_LONG is slightly wrong, since it's
+                         * always 64 bits per register in chip...
+                         * We only work on 64 bit kernels, so that's OK.
+                         */
+                        /* deal with 6110 chip bug on high register #s */
+                        i = start / BITS_PER_LONG;
+                        im = (i > 3 && (dd->ipath_flags & IPATH_SWAP_PIOBUFS)) ?
+                                i ^ 1 : i;
+                        __clear_bit(INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT
+                                + start, dd->ipath_pioavailshadow);
+                        dma = (unsigned long) le64_to_cpu(
+                                dd->ipath_pioavailregs_dma[im]);
+                        if (test_bit((INFINIPATH_SENDPIOAVAIL_CHECK_SHIFT
+                                + start) % BITS_PER_LONG, &dma))
+                                __set_bit(INFINIPATH_SENDPIOAVAIL_CHECK_SHIFT
+                                        + start, dd->ipath_pioavailshadow);
+                        else
+                                __clear_bit(INFINIPATH_SENDPIOAVAIL_CHECK_SHIFT
+                                        + start, dd->ipath_pioavailshadow);
                         __set_bit(start, dd->ipath_pioavailkernel);
                 } else {
                         __set_bit(start + INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT,
@@ -1673,7 +1740,44 @@ void ipath_chg_pioavailkernel(struct ipath_devdata *dd, unsigned start,
                 }
                 start += 2;
         }
+
+        if (dd->ipath_pioupd_thresh) {
+                end = 2 * (dd->ipath_piobcnt2k + dd->ipath_piobcnt4k);
+                next = find_first_bit(dd->ipath_pioavailkernel, end);
+                while (next < end) {
+                        cnt++;
+                        next = find_next_bit(dd->ipath_pioavailkernel, end,
+                                        next + 1);
+                }
+        }
         spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
+
+        /*
+         * When moving buffers from kernel to user, if number assigned to
+         * the user is less than the pio update threshold, and threshold
+         * is supported (cnt was computed > 0), drop the update threshold
+         * so we update at least once per allocated number of buffers.
+         * In any case, if the kernel buffers are less than the threshold,
+         * drop the threshold.  We don't bother increasing it, having once
+         * decreased it, since it would typically just cycle back and forth.
+         * If we don't decrease below buffers in use, we can wait a long
+         * time for an update, until some other context uses PIO buffers.
+         */
+        if (!avail && len < cnt)
+                cnt = len;
+        if (cnt < dd->ipath_pioupd_thresh) {
+                dd->ipath_pioupd_thresh = cnt;
+                ipath_dbg("Decreased pio update threshold to %u\n",
+                        dd->ipath_pioupd_thresh);
+                spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+                dd->ipath_sendctrl &= ~(INFINIPATH_S_UPDTHRESH_MASK
+                        << INFINIPATH_S_UPDTHRESH_SHIFT);
+                dd->ipath_sendctrl |= dd->ipath_pioupd_thresh
+                        << INFINIPATH_S_UPDTHRESH_SHIFT;
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+                        dd->ipath_sendctrl);
+                spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+        }
 }
 
 /**
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 8b1752202e78..3295177c937e 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -173,47 +173,25 @@ static int ipath_get_base_info(struct file *fp,
                 (void *) dd->ipath_statusp -
                 (void *) dd->ipath_pioavailregs_dma;
         if (!shared) {
-                kinfo->spi_piocnt = dd->ipath_pbufsport;
+                kinfo->spi_piocnt = pd->port_piocnt;
                 kinfo->spi_piobufbase = (u64) pd->port_piobufs;
                 kinfo->__spi_uregbase = (u64) dd->ipath_uregbase +
                         dd->ipath_ureg_align * pd->port_port;
         } else if (master) {
-                kinfo->spi_piocnt = (dd->ipath_pbufsport / subport_cnt) +
-                                    (dd->ipath_pbufsport % subport_cnt);
+                kinfo->spi_piocnt = (pd->port_piocnt / subport_cnt) +
+                                    (pd->port_piocnt % subport_cnt);
                 /* Master's PIO buffers are after all the slave's */
                 kinfo->spi_piobufbase = (u64) pd->port_piobufs +
                         dd->ipath_palign *
-                        (dd->ipath_pbufsport - kinfo->spi_piocnt);
+                        (pd->port_piocnt - kinfo->spi_piocnt);
         } else {
                 unsigned slave = subport_fp(fp) - 1;
 
-                kinfo->spi_piocnt = dd->ipath_pbufsport / subport_cnt;
+                kinfo->spi_piocnt = pd->port_piocnt / subport_cnt;
                 kinfo->spi_piobufbase = (u64) pd->port_piobufs +
                         dd->ipath_palign * kinfo->spi_piocnt * slave;
         }
 
-        /*
-         * Set the PIO avail update threshold to no larger
-         * than the number of buffers per process. Note that
-         * we decrease it here, but won't ever increase it.
-         */
-        if (dd->ipath_pioupd_thresh &&
-            kinfo->spi_piocnt < dd->ipath_pioupd_thresh) {
-                unsigned long flags;
-
-                dd->ipath_pioupd_thresh = kinfo->spi_piocnt;
-                ipath_dbg("Decreased pio update threshold to %u\n",
-                        dd->ipath_pioupd_thresh);
-                spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
-                dd->ipath_sendctrl &= ~(INFINIPATH_S_UPDTHRESH_MASK
-                        << INFINIPATH_S_UPDTHRESH_SHIFT);
-                dd->ipath_sendctrl |= dd->ipath_pioupd_thresh
-                        << INFINIPATH_S_UPDTHRESH_SHIFT;
-                ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-                        dd->ipath_sendctrl);
-                spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
-        }
-
         if (shared) {
                 kinfo->spi_port_uregbase = (u64) dd->ipath_uregbase +
                         dd->ipath_ureg_align * pd->port_port;
@@ -1309,19 +1287,19 @@ static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
         ureg = dd->ipath_uregbase + dd->ipath_ureg_align * pd->port_port;
         if (!pd->port_subport_cnt) {
                 /* port is not shared */
-                piocnt = dd->ipath_pbufsport;
+                piocnt = pd->port_piocnt;
                 piobufs = pd->port_piobufs;
         } else if (!subport_fp(fp)) {
                 /* caller is the master */
-                piocnt = (dd->ipath_pbufsport / pd->port_subport_cnt) +
-                         (dd->ipath_pbufsport % pd->port_subport_cnt);
+                piocnt = (pd->port_piocnt / pd->port_subport_cnt) +
+                         (pd->port_piocnt % pd->port_subport_cnt);
                 piobufs = pd->port_piobufs +
-                        dd->ipath_palign * (dd->ipath_pbufsport - piocnt);
+                        dd->ipath_palign * (pd->port_piocnt - piocnt);
         } else {
                 unsigned slave = subport_fp(fp) - 1;
 
                 /* caller is a slave */
-                piocnt = dd->ipath_pbufsport / pd->port_subport_cnt;
+                piocnt = pd->port_piocnt / pd->port_subport_cnt;
                 piobufs = pd->port_piobufs + dd->ipath_palign * piocnt * slave;
         }
 
@@ -1633,9 +1611,6 @@ static int try_alloc_port(struct ipath_devdata *dd, int port,
                 port_fp(fp) = pd;
                 pd->port_pid = current->pid;
                 strncpy(pd->port_comm, current->comm, sizeof(pd->port_comm));
-                ipath_chg_pioavailkernel(dd,
-                        dd->ipath_pbufsport * (pd->port_port - 1),
-                        dd->ipath_pbufsport, 0);
                 ipath_stats.sps_ports++;
                 ret = 0;
         } else
@@ -1938,11 +1913,25 @@ static int ipath_do_user_init(struct file *fp,
 
         /* for now we do nothing with rcvhdrcnt: uinfo->spu_rcvhdrcnt */
 
+        /* some ports may get extra buffers, calculate that here */
+        if (pd->port_port <= dd->ipath_ports_extrabuf)
+                pd->port_piocnt = dd->ipath_pbufsport + 1;
+        else
+                pd->port_piocnt = dd->ipath_pbufsport;
+
         /* for right now, kernel piobufs are at end, so port 1 is at 0 */
+        if (pd->port_port <= dd->ipath_ports_extrabuf)
+                pd->port_pio_base = (dd->ipath_pbufsport + 1)
+                        * (pd->port_port - 1);
+        else
+                pd->port_pio_base = dd->ipath_ports_extrabuf +
+                        dd->ipath_pbufsport * (pd->port_port - 1);
         pd->port_piobufs = dd->ipath_piobufbase +
-                dd->ipath_pbufsport * (pd->port_port - 1) * dd->ipath_palign;
-        ipath_cdbg(VERBOSE, "Set base of piobufs for port %u to 0x%x\n",
-                   pd->port_port, pd->port_piobufs);
+                pd->port_pio_base * dd->ipath_palign;
+        ipath_cdbg(VERBOSE, "piobuf base for port %u is 0x%x, piocnt %u,"
+                " first pio %u\n", pd->port_port, pd->port_piobufs,
+                pd->port_piocnt, pd->port_pio_base);
+        ipath_chg_pioavailkernel(dd, pd->port_pio_base, pd->port_piocnt, 0);
 
         /*
          * Now allocate the rcvhdr Q and eager TIDs; skip the TID
@@ -2107,7 +2096,6 @@ static int ipath_close(struct inode *in, struct file *fp)
         }
 
         if (dd->ipath_kregbase) {
-                int i;
                 /* atomically clear receive enable port and intr avail. */
                 clear_bit(dd->ipath_r_portenable_shift + port,
                           &dd->ipath_rcvctrl);
@@ -2136,9 +2124,9 @@ static int ipath_close(struct inode *in, struct file *fp)
                 ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr,
                         pd->port_port, dd->ipath_dummy_hdrq_phys);
 
-                i = dd->ipath_pbufsport * (port - 1);
-                ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport);
-                ipath_chg_pioavailkernel(dd, i, dd->ipath_pbufsport, 1);
+                ipath_disarm_piobufs(dd, pd->port_pio_base, pd->port_piocnt);
+                ipath_chg_pioavailkernel(dd, pd->port_pio_base,
+                        pd->port_piocnt, 1);
 
                 dd->ipath_f_clear_tids(dd, pd->port_port);
 
diff --git a/drivers/infiniband/hw/ipath/ipath_iba7220.c b/drivers/infiniband/hw/ipath/ipath_iba7220.c
index 5f693de66542..8eee7830f042 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba7220.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba7220.c
@@ -595,7 +595,7 @@ static void ipath_7220_txe_recover(struct ipath_devdata *dd)
 
         dev_info(&dd->pcidev->dev,
                 "Recovering from TXE PIO parity error\n");
-        ipath_disarm_senderrbufs(dd, 1);
+        ipath_disarm_senderrbufs(dd);
 }
 
 
@@ -675,10 +675,8 @@ static void ipath_7220_handle_hwerrors(struct ipath_devdata *dd, char *msg,
         ctrl = ipath_read_kreg32(dd, dd->ipath_kregs->kr_control);
         if ((ctrl & INFINIPATH_C_FREEZEMODE) && !ipath_diag_inuse) {
                 /*
-                 * Parity errors in send memory are recoverable,
-                 * just cancel the send (if indicated in * sendbuffererror),
-                 * count the occurrence, unfreeze (if no other handled
-                 * hardware error bits are set), and continue.
+                 * Parity errors in send memory are recoverable by h/w
+                 * just do housekeeping, exit freeze mode and continue.
                  */
                 if (hwerrs & ((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
                                INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
@@ -687,13 +685,6 @@ static void ipath_7220_handle_hwerrors(struct ipath_devdata *dd, char *msg,
                         hwerrs &= ~((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
                                      INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
                                     << INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT);
-                        if (!hwerrs) {
-                                /* else leave in freeze mode */
-                                ipath_write_kreg(dd,
-                                                 dd->ipath_kregs->kr_control,
-                                                 dd->ipath_control);
-                                goto bail;
-                        }
                 }
                 if (hwerrs) {
                         /*
@@ -723,8 +714,8 @@ static void ipath_7220_handle_hwerrors(struct ipath_devdata *dd, char *msg,
                         *dd->ipath_statusp |= IPATH_STATUS_HWERROR;
                         dd->ipath_flags &= ~IPATH_INITTED;
                 } else {
-                        ipath_dbg("Clearing freezemode on ignored hardware "
-                                  "error\n");
+                        ipath_dbg("Clearing freezemode on ignored or "
+                                "recovered hardware error\n");
                         ipath_clear_freeze(dd);
                 }
         }
@@ -1967,7 +1958,7 @@ static void ipath_7220_config_ports(struct ipath_devdata *dd, ushort cfgports)
                          dd->ipath_rcvctrl);
         dd->ipath_p0_rcvegrcnt = 2048; /* always */
         if (dd->ipath_flags & IPATH_HAS_SEND_DMA)
-                dd->ipath_pioreserved = 1; /* reserve a buffer */
+                dd->ipath_pioreserved = 3; /* kpiobufs used for PIO */
 }
 
 
diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 27dd89476660..3e5baa43fc82 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -41,7 +41,7 @@
 /*
  * min buffers we want to have per port, after driver
  */
-#define IPATH_MIN_USER_PORT_BUFCNT 8
+#define IPATH_MIN_USER_PORT_BUFCNT 7
 
 /*
  * Number of ports we are configured to use (to allow for more pio
@@ -54,13 +54,9 @@ MODULE_PARM_DESC(cfgports, "Set max number of ports to use");
 
 /*
  * Number of buffers reserved for driver (verbs and layered drivers.)
- * Reserved at end of buffer list.   Initialized based on
- * number of PIO buffers if not set via module interface.
+ * Initialized based on number of PIO buffers if not set via module interface.
  * The problem with this is that it's global, but we'll use different
- * numbers for different chip types.  So the default value is not
- * very useful.  I've redefined it for the 1.3 release so that it's
- * zero unless set by the user to something else, in which case we
- * try to respect it.
+ * numbers for different chip types.
  */
 static ushort ipath_kpiobufs;
 
@@ -546,9 +542,12 @@ static void enable_chip(struct ipath_devdata *dd, int reinit)
                         pioavail = dd->ipath_pioavailregs_dma[i ^ 1];
                 else
                         pioavail = dd->ipath_pioavailregs_dma[i];
-                dd->ipath_pioavailshadow[i] = le64_to_cpu(pioavail) |
-                        (~dd->ipath_pioavailkernel[i] <<
-                        INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT);
+                /*
+                 * don't need to worry about ipath_pioavailkernel here
+                 * because we will call ipath_chg_pioavailkernel() later
+                 * in initialization, to busy out buffers as needed
+                 */
+                dd->ipath_pioavailshadow[i] = le64_to_cpu(pioavail);
         }
         /* can get counters, stats, etc. */
         dd->ipath_flags |= IPATH_PRESENT;
@@ -708,12 +707,11 @@ static void verify_interrupt(unsigned long opaque)
 int ipath_init_chip(struct ipath_devdata *dd, int reinit)
 {
         int ret = 0;
-        u32 val32, kpiobufs;
+        u32 kpiobufs, defkbufs;
         u32 piobufs, uports;
         u64 val;
         struct ipath_portdata *pd;
         gfp_t gfp_flags = GFP_USER | __GFP_COMP;
-        unsigned long flags;
 
         ret = init_housekeeping(dd, reinit);
         if (ret)
@@ -753,56 +751,46 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
         dd->ipath_pioavregs = ALIGN(piobufs, sizeof(u64) * BITS_PER_BYTE / 2)
                 / (sizeof(u64) * BITS_PER_BYTE / 2);
         uports = dd->ipath_cfgports ? dd->ipath_cfgports - 1 : 0;
-        if (ipath_kpiobufs == 0) {
-                /* not set by user (this is default) */
-                if (piobufs > 144)
-                        kpiobufs = 32;
-                else
-                        kpiobufs = 16;
-        }
+        if (piobufs > 144)
+                defkbufs = 32 + dd->ipath_pioreserved;
         else
-                kpiobufs = ipath_kpiobufs;
+                defkbufs = 16 + dd->ipath_pioreserved;
 
-        if (kpiobufs + (uports * IPATH_MIN_USER_PORT_BUFCNT) > piobufs) {
+        if (ipath_kpiobufs && (ipath_kpiobufs +
+                (uports * IPATH_MIN_USER_PORT_BUFCNT)) > piobufs) {
                 int i = (int) piobufs -
                         (int) (uports * IPATH_MIN_USER_PORT_BUFCNT);
                 if (i < 1)
                         i = 1;
                 dev_info(&dd->pcidev->dev, "Allocating %d PIO bufs of "
                          "%d for kernel leaves too few for %d user ports "
-                         "(%d each); using %u\n", kpiobufs,
+                         "(%d each); using %u\n", ipath_kpiobufs,
                          piobufs, uports, IPATH_MIN_USER_PORT_BUFCNT, i);
                 /*
                  * shouldn't change ipath_kpiobufs, because could be
                  * different for different devices...
                  */
                 kpiobufs = i;
-        }
+        } else if (ipath_kpiobufs)
+                kpiobufs = ipath_kpiobufs;
+        else
+                kpiobufs = defkbufs;
         dd->ipath_lastport_piobuf = piobufs - kpiobufs;
         dd->ipath_pbufsport =
                 uports ? dd->ipath_lastport_piobuf / uports : 0;
-        val32 = dd->ipath_lastport_piobuf - (dd->ipath_pbufsport * uports);
-        if (val32 > 0) {
-                ipath_dbg("allocating %u pbufs/port leaves %u unused, "
-                          "add to kernel\n", dd->ipath_pbufsport, val32);
-                dd->ipath_lastport_piobuf -= val32;
-                kpiobufs += val32;
-                ipath_dbg("%u pbufs/port leaves %u unused, add to kernel\n",
-                          dd->ipath_pbufsport, val32);
-        }
+        /* if not an even divisor, some user ports get extra buffers */
+        dd->ipath_ports_extrabuf = dd->ipath_lastport_piobuf -
+                (dd->ipath_pbufsport * uports);
+        if (dd->ipath_ports_extrabuf)
+                ipath_dbg("%u pbufs/port leaves some unused, add 1 buffer to "
+                        "ports <= %u\n", dd->ipath_pbufsport,
+                        dd->ipath_ports_extrabuf);
         dd->ipath_lastpioindex = 0;
         dd->ipath_lastpioindexl = dd->ipath_piobcnt2k;
-        ipath_chg_pioavailkernel(dd, 0, piobufs, 1);
+        /* ipath_pioavailshadow initialized earlier */
         ipath_cdbg(VERBOSE, "%d PIO bufs for kernel out of %d total %u "
                    "each for %u user ports\n", kpiobufs,
                    piobufs, dd->ipath_pbufsport, uports);
-        if (dd->ipath_pioupd_thresh) {
-                if (dd->ipath_pbufsport < dd->ipath_pioupd_thresh)
-                        dd->ipath_pioupd_thresh = dd->ipath_pbufsport;
-                if (kpiobufs < dd->ipath_pioupd_thresh)
-                        dd->ipath_pioupd_thresh = kpiobufs;
-        }
-
         ret = dd->ipath_f_early_init(dd);
         if (ret) {
                 ipath_dev_err(dd, "Early initialization failure\n");
@@ -810,13 +798,6 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
         }
 
         /*
-         * Cancel any possible active sends from early driver load.
-         * Follows early_init because some chips have to initialize
-         * PIO buffers in early_init to avoid false parity errors.
-         */
-        ipath_cancel_sends(dd, 0);
-
-        /*
          * Early_init sets rcvhdrentsize and rcvhdrsize, so this must be
          * done after early_init.
          */
@@ -836,6 +817,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
 
         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendpioavailaddr,
                          dd->ipath_pioavailregs_phys);
+
         /*
          * this is to detect s/w errors, which the h/w works around by
          * ignoring the low 6 bits of address, if it wasn't aligned.
@@ -862,12 +844,6 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
                          ~0ULL&~INFINIPATH_HWE_MEMBISTFAILED);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0ULL);
 
-        spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
-        dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE;
-        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);
-
         /*
          * before error clears, since we expect serdes pll errors during
          * this, the first time after reset
@@ -940,6 +916,19 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
         else
                 enable_chip(dd, reinit);
 
+        /* after enable_chip, so pioavailshadow setup */
+        ipath_chg_pioavailkernel(dd, 0, piobufs, 1);
+
+        /*
+         * Cancel any possible active sends from early driver load.
+         * Follows early_init because some chips have to initialize
+         * PIO buffers in early_init to avoid false parity errors.
+         * After enable and ipath_chg_pioavailkernel so we can safely
+         * enable pioavail updates and PIOENABLE; packets are now
+         * ready to go out.
+         */
+        ipath_cancel_sends(dd, 1);
+
         if (!reinit) {
                 /*
                  * Used when we close a port, for DMA already in flight
diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index 45c4c068ab1e..26900b3b7a4e 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -38,42 +38,12 @@
 #include "ipath_verbs.h"
 #include "ipath_common.h"
 
-/*
- * clear (write) a pio buffer, to clear a parity error.   This routine
- * should only be called when in freeze mode, and the buffer should be
- * canceled afterwards.
- */
-static void ipath_clrpiobuf(struct ipath_devdata *dd, u32 pnum)
-{
-        u32 __iomem *pbuf;
-        u32 dwcnt; /* dword count to write */
-        if (pnum < dd->ipath_piobcnt2k) {
-                pbuf = (u32 __iomem *) (dd->ipath_pio2kbase + pnum *
-                        dd->ipath_palign);
-                dwcnt = dd->ipath_piosize2k >> 2;
-        }
-        else {
-                pbuf = (u32 __iomem *) (dd->ipath_pio4kbase +
-                        (pnum - dd->ipath_piobcnt2k) * dd->ipath_4kalign);
-                dwcnt = dd->ipath_piosize4k >> 2;
-        }
-        dev_info(&dd->pcidev->dev,
-                "Rewrite PIO buffer %u, to recover from parity error\n",
-                pnum);
-
-        /* no flush required, since already in freeze */
-        writel(dwcnt + 1, pbuf);
-        while (--dwcnt)
-                writel(0, pbuf++);
-}
 
 /*
  * 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.
- * If rewrite is true, and bits are set in the sendbufferror registers,
- * we'll write to the buffer, for error recovery on parity errors.
  */
-void ipath_disarm_senderrbufs(struct ipath_devdata *dd, int rewrite)
+void ipath_disarm_senderrbufs(struct ipath_devdata *dd)
 {
         u32 piobcnt;
         unsigned long sbuf[4];
@@ -109,11 +79,8 @@ void ipath_disarm_senderrbufs(struct ipath_devdata *dd, int rewrite)
                 }
 
                 for (i = 0; i < piobcnt; i++)
-                        if (test_bit(i, sbuf)) {
-                                if (rewrite)
-                                        ipath_clrpiobuf(dd, i);
+                        if (test_bit(i, sbuf))
                                 ipath_disarm_piobufs(dd, i, 1);
-                        }
                 /* ignore armlaunch errs for a bit */
                 dd->ipath_lastcancel = jiffies+3;
         }
@@ -164,7 +131,7 @@ static u64 handle_e_sum_errs(struct ipath_devdata *dd, ipath_err_t errs)
 {
         u64 ignore_this_time = 0;
 
-        ipath_disarm_senderrbufs(dd, 0);
+        ipath_disarm_senderrbufs(dd);
         if ((errs & E_SUM_LINK_PKTERRS) &&
             !(dd->ipath_flags & IPATH_LINKACTIVE)) {
                 /*
@@ -909,8 +876,8 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
  * 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 for anything changing while in freeze mode
- * (we don't want to wait for the next pio buffer state change).
+ * 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
@@ -918,48 +885,23 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
  */
 void ipath_clear_freeze(struct ipath_devdata *dd)
 {
-        int i, im;
-        u64 val;
-
         /* 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);
 
-        /*
-         * clear all sends, because they have may been
-         * completed by usercode while in freeze mode, and
-         * therefore would not be sent, and eventually
-         * might cause the process to run out of bufs
-         */
         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);
 
-        /*
-         * ensure pio avail updates continue (because the update
-         * won't have happened from cancel_sends because we were
-         * still in freeze
-         */
+        /* force in-memory update now we are out of freeze */
         ipath_force_pio_avail_update(dd);
 
         /*
-         * We just enabled pioavailupdate, so dma copy is almost certainly
-         * not yet right, so read the registers directly.  Similar to init
-         */
-        for (i = 0; i < dd->ipath_pioavregs; i++) {
-                /* deal with 6110 chip bug */
-                im = (i > 3 && (dd->ipath_flags & IPATH_SWAP_PIOBUFS)) ?
-                        i ^ 1 : i;
-                val = ipath_read_kreg64(dd, (0x1000 / sizeof(u64)) + im);
-                dd->ipath_pioavailregs_dma[i] = cpu_to_le64(val);
-                dd->ipath_pioavailshadow[i] = val |
-                        (~dd->ipath_pioavailkernel[i] <<
-                        INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT);
-        }
-
-        /*
          * 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
@@ -1316,10 +1258,8 @@ irqreturn_t ipath_intr(int irq, void *data)
                 ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
                 spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
 
-                if (!(dd->ipath_flags & IPATH_HAS_SEND_DMA))
-                        handle_layer_pioavail(dd);
-                else
-                        ipath_dbg("unexpected BUFAVAIL intr\n");
+                /* always process; sdma verbs uses PIO for acks and VL15  */
+                handle_layer_pioavail(dd);
         }
 
         ret = IRQ_HANDLED;
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index 202337ae90dc..02b24a340599 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -117,6 +117,10 @@ struct ipath_portdata {
         u16 port_subport_cnt;
         /* non-zero if port is being shared. */
         u16 port_subport_id;
+        /* number of pio bufs for this port (all procs, if shared) */
+        u32 port_piocnt;
+        /* first pio buffer for this port */
+        u32 port_pio_base;
         /* chip offset of PIO buffers for this port */
         u32 port_piobufs;
         /* how many alloc_pages() chunks in port_rcvegrbuf_pages */
@@ -384,6 +388,8 @@ struct ipath_devdata {
         u32 ipath_lastrpkts;
         /* pio bufs allocated per port */
         u32 ipath_pbufsport;
+        /* if remainder on bufs/port, ports < extrabuf get 1 extra */
+        u32 ipath_ports_extrabuf;
         u32 ipath_pioupd_thresh; /* update threshold, some chips */
         /*
          * number of ports configured as max; zero is set to number chip
@@ -1011,7 +1017,7 @@ void ipath_get_eeprom_info(struct ipath_devdata *);
 int ipath_update_eeprom_log(struct ipath_devdata *dd);
 void ipath_inc_eeprom_err(struct ipath_devdata *dd, u32 eidx, u32 incr);
 u64 ipath_snap_cntr(struct ipath_devdata *, ipath_creg);
-void ipath_disarm_senderrbufs(struct ipath_devdata *, int);
+void ipath_disarm_senderrbufs(struct ipath_devdata *);
 void ipath_force_pio_avail_update(struct ipath_devdata *);
 void signal_ib_event(struct ipath_devdata *dd, enum ib_event_type ev);
 
diff --git a/drivers/infiniband/hw/ipath/ipath_ruc.c b/drivers/infiniband/hw/ipath/ipath_ruc.c
index 8ac5c1d82ccd..9e3fe61cbd08 100644
--- a/drivers/infiniband/hw/ipath/ipath_ruc.c
+++ b/drivers/infiniband/hw/ipath/ipath_ruc.c
@@ -481,9 +481,10 @@ done:
                 wake_up(&qp->wait);
 }
 
-static void want_buffer(struct ipath_devdata *dd)
+static void want_buffer(struct ipath_devdata *dd, struct ipath_qp *qp)
 {
-        if (!(dd->ipath_flags & IPATH_HAS_SEND_DMA)) {
+        if (!(dd->ipath_flags & IPATH_HAS_SEND_DMA) ||
+                qp->ibqp.qp_type == IB_QPT_SMI) {
                 unsigned long flags;
 
                 spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
@@ -519,7 +520,7 @@ static void ipath_no_bufs_available(struct ipath_qp *qp,
         spin_lock_irqsave(&dev->pending_lock, flags);
         list_add_tail(&qp->piowait, &dev->piowait);
         spin_unlock_irqrestore(&dev->pending_lock, flags);
-        want_buffer(dev->dd);
+        want_buffer(dev->dd, qp);
         dev->n_piowait++;
 }
 
diff --git a/drivers/infiniband/hw/ipath/ipath_sdma.c b/drivers/infiniband/hw/ipath/ipath_sdma.c
index 1974df7a9f78..0d07682c7310 100644
--- a/drivers/infiniband/hw/ipath/ipath_sdma.c
+++ b/drivers/infiniband/hw/ipath/ipath_sdma.c
@@ -449,16 +449,19 @@ int setup_sdma(struct ipath_devdata *dd)
         ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmaheadaddr,
                          dd->ipath_sdma_head_phys);
 
-        /* Reserve all the former "kernel" piobufs */
-        n = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k - dd->ipath_pioreserved;
-        for (i = dd->ipath_lastport_piobuf; i < n; ++i) {
+        /*
+         * Reserve all the former "kernel" piobufs, using high number range
+         * so we get as many 4K buffers as possible
+         */
+        n = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
+        i = dd->ipath_lastport_piobuf + dd->ipath_pioreserved;
+        ipath_chg_pioavailkernel(dd, i, n - i , 0);
+        for (; i < n; ++i) {
                 unsigned word = i / 64;
                 unsigned bit = i & 63;
                 BUG_ON(word >= 3);
                 senddmabufmask[word] |= 1ULL << bit;
         }
-        ipath_chg_pioavailkernel(dd, dd->ipath_lastport_piobuf,
-                n - dd->ipath_lastport_piobuf, 0);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmabufmask0,
                          senddmabufmask[0]);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmabufmask1,