IB/ipath: Fix and recover TXE piobuf and PBC parity errors

We can sometimes trigger parity errors due to processor speculative
reads to our write-combined memory (mostly seen on Woodcrest).   Add a
stats counter for these.

Factored out the sendbuffererror buffer cancellation code so it can be
used in the new handling; suppress likely subsequent error messages if
within two jiffies of the cancellation.

Also restore 2 dropped TXE lines on hwe_bitsextant noticed while
debugging.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

5 files changed, 124 insertions, 52 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_common.h b/drivers/infiniband/hw/ipath/ipath_common.h
index 382956d2ea4b..a9b109a353bc 100644
--- a/drivers/infiniband/hw/ipath/ipath_common.h
+++ b/drivers/infiniband/hw/ipath/ipath_common.h
@@ -141,8 +141,9 @@ struct infinipath_stats {
          * packets if ipath not configured, etc.)
          */
         __u64 sps_krdrops;
+        __u64 sps_txeparity; /* PIO buffer parity error, recovered */
         /* pad for future growth */
-        __u64 __sps_pad[46];
+        __u64 __sps_pad[45];
 };
 
 /*
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6110.c b/drivers/infiniband/hw/ipath/ipath_iba6110.c
index fd49c9c32c68..9e4e8d4c6e20 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6110.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6110.c
@@ -451,7 +451,10 @@ static void ipath_ht_handle_hwerrors(struct ipath_devdata *dd, char *msg,
          * make sure we get this much out, unless told to be quiet,
          * or it's occurred within the last 5 seconds
          */
-        if ((hwerrs & ~dd->ipath_lasthwerror) ||
+        if ((hwerrs & ~(dd->ipath_lasthwerror |
+                        ((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
+                          INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
+                        << INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT))) ||
             (ipath_debug & __IPATH_VERBDBG))
                 dev_info(&dd->pcidev->dev, "Hardware error: hwerr=0x%llx "
                          "(cleared)\n", (unsigned long long) hwerrs);
@@ -464,6 +467,33 @@ static void ipath_ht_handle_hwerrors(struct ipath_devdata *dd, char *msg,
 
         ctrl = ipath_read_kreg32(dd, dd->ipath_kregs->kr_control);
         if (ctrl & INFINIPATH_C_FREEZEMODE) {
+                /*
+                 * 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. They can
+                 * occur if a processor speculative read is done to the PIO
+                 * buffer while we are sending a packet, for example.
+                 */
+                if (hwerrs & ((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
+                               INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
+                              << INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT)) {
+                        ipath_stats.sps_txeparity++;
+                        ipath_dbg("Recovering from TXE parity error (%llu), "
+                                  "hwerrstatus=%llx\n",
+                                  (unsigned long long) ipath_stats.sps_txeparity,
+                                  (unsigned long long) hwerrs);
+                        ipath_disarm_senderrbufs(dd);
+                        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);
+                                return;
+                        }
+                }
                 if (hwerrs) {
                         /*
                          * if any set that we aren't ignoring; only
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6120.c b/drivers/infiniband/hw/ipath/ipath_iba6120.c
index 08a44dd9ed6f..024b6aa320f1 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6120.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6120.c
@@ -370,7 +370,10 @@ static void ipath_pe_handle_hwerrors(struct ipath_devdata *dd, char *msg,
          * make sure we get this much out, unless told to be quiet,
          * or it's occurred within the last 5 seconds
          */
-        if ((hwerrs & ~dd->ipath_lasthwerror) ||
+        if ((hwerrs & ~(dd->ipath_lasthwerror |
+                        ((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
+                          INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
+                         << INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT))) ||
             (ipath_debug & __IPATH_VERBDBG))
                 dev_info(&dd->pcidev->dev, "Hardware error: hwerr=0x%llx "
                          "(cleared)\n", (unsigned long long) hwerrs);
@@ -383,6 +386,33 @@ static void ipath_pe_handle_hwerrors(struct ipath_devdata *dd, char *msg,
 
         ctrl = ipath_read_kreg32(dd, dd->ipath_kregs->kr_control);
         if (ctrl & INFINIPATH_C_FREEZEMODE) {
+                /*
+                 * 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. They can
+                 * occur if a processor speculative read is done to the PIO
+                 * buffer while we are sending a packet, for example.
+                 */
+                if (hwerrs & ((INFINIPATH_HWE_TXEMEMPARITYERR_PIOBUF |
+                               INFINIPATH_HWE_TXEMEMPARITYERR_PIOPBC)
+                              << INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT)) {
+                        ipath_stats.sps_txeparity++;
+                        ipath_dbg("Recovering from TXE parity error (%llu), "
+                                  "hwerrstatus=%llx\n",
+                                  (unsigned long long) ipath_stats.sps_txeparity,
+                                  (unsigned long long) hwerrs);
+                        ipath_disarm_senderrbufs(dd);
+                        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);
+                            return;
+                        }
+                }
                 if (hwerrs) {
                         /*
                          * if any set that we aren't ignoring only make the
@@ -406,9 +436,8 @@ static void ipath_pe_handle_hwerrors(struct ipath_devdata *dd, char *msg,
                 } else {
                         ipath_dbg("Clearing freezemode on ignored hardware "
                                   "error\n");
-                        ctrl &= ~INFINIPATH_C_FREEZEMODE;
                         ipath_write_kreg(dd, dd->ipath_kregs->kr_control,
-                                         ctrl);
+                                         dd->ipath_control);
                 }
         }
 
@@ -880,6 +909,8 @@ static void ipath_init_pe_variables(struct ipath_devdata *dd)
         dd->ipath_hwe_bitsextant =
                 (INFINIPATH_HWE_RXEMEMPARITYERR_MASK <<
                  INFINIPATH_HWE_RXEMEMPARITYERR_SHIFT) |
+                (INFINIPATH_HWE_TXEMEMPARITYERR_MASK <<
+                 INFINIPATH_HWE_TXEMEMPARITYERR_SHIFT) |
                 (INFINIPATH_HWE_PCIEMEMPARITYERR_MASK <<
                  INFINIPATH_HWE_PCIEMEMPARITYERR_SHIFT) |
                 INFINIPATH_HWE_PCIE1PLLFAILED |
diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index f4d8aafc6306..6bee53ce5f33 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -37,6 +37,50 @@
 #include "ipath_verbs.h"
 #include "ipath_common.h"
 
+/*
+ * Called when we might have an error that is specific to a particular
+ * PIO buffer, and may need to cancel that buffer, so it can be re-used.
+ */
+void ipath_disarm_senderrbufs(struct ipath_devdata *dd)
+{
+        u32 piobcnt;
+        unsigned long sbuf[4];
+        /*
+         * it's possible that sendbuffererror could have bits set; might
+         * have already done this as a result of hardware error handling
+         */
+        piobcnt = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
+        /* read these before writing errorclear */
+        sbuf[0] = ipath_read_kreg64(
+                dd, dd->ipath_kregs->kr_sendbuffererror);
+        sbuf[1] = ipath_read_kreg64(
+                dd, dd->ipath_kregs->kr_sendbuffererror + 1);
+        if (piobcnt > 128) {
+                sbuf[2] = ipath_read_kreg64(
+                        dd, dd->ipath_kregs->kr_sendbuffererror + 2);
+                sbuf[3] = ipath_read_kreg64(
+                        dd, dd->ipath_kregs->kr_sendbuffererror + 3);
+        }
+
+        if (sbuf[0] || sbuf[1] || (piobcnt > 128 && (sbuf[2] || sbuf[3]))) {
+                int i;
+                if (ipath_debug & (__IPATH_PKTDBG|__IPATH_DBG)) {
+                        __IPATH_DBG_WHICH(__IPATH_PKTDBG|__IPATH_DBG,
+                                          "SendbufErrs %lx %lx", sbuf[0],
+                                          sbuf[1]);
+                        if (ipath_debug & __IPATH_PKTDBG && piobcnt > 128)
+                                printk(" %lx %lx ", sbuf[2], sbuf[3]);
+                        printk("\n");
+                }
+
+                for (i = 0; i < piobcnt; i++)
+                        if (test_bit(i, sbuf))
+                                ipath_disarm_piobufs(dd, i, 1);
+                dd->ipath_lastcancel = jiffies+3; /* no armlaunch for a bit */
+        }
+}
+
+
 /* These are all rcv-related errors which we want to count for stats */
 #define E_SUM_PKTERRS \
         (INFINIPATH_E_RHDRLEN | INFINIPATH_E_RBADTID | \
@@ -68,53 +112,9 @@
 
 static u64 handle_e_sum_errs(struct ipath_devdata *dd, ipath_err_t errs)
 {
-        unsigned long sbuf[4];
         u64 ignore_this_time = 0;
-        u32 piobcnt;
-
-        /* if possible that sendbuffererror could be valid */
-        piobcnt = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
-        /* read these before writing errorclear */
-        sbuf[0] = ipath_read_kreg64(
-                dd, dd->ipath_kregs->kr_sendbuffererror);
-        sbuf[1] = ipath_read_kreg64(
-                dd, dd->ipath_kregs->kr_sendbuffererror + 1);
-        if (piobcnt > 128) {
-                sbuf[2] = ipath_read_kreg64(
-                        dd, dd->ipath_kregs->kr_sendbuffererror + 2);
-                sbuf[3] = ipath_read_kreg64(
-                        dd, dd->ipath_kregs->kr_sendbuffererror + 3);
-        }
 
-        if (sbuf[0] || sbuf[1] || (piobcnt > 128 && (sbuf[2] || sbuf[3]))) {
-                int i;
-
-                ipath_cdbg(PKT, "SendbufErrs %lx %lx ", sbuf[0], sbuf[1]);
-                if (ipath_debug & __IPATH_PKTDBG && piobcnt > 128)
-                        printk("%lx %lx ", sbuf[2], sbuf[3]);
-                for (i = 0; i < piobcnt; i++) {
-                        if (test_bit(i, sbuf)) {
-                                u32 __iomem *piobuf;
-                                if (i < dd->ipath_piobcnt2k)
-                                        piobuf = (u32 __iomem *)
-                                                (dd->ipath_pio2kbase +
-                                                 i * dd->ipath_palign);
-                                else
-                                        piobuf = (u32 __iomem *)
-                                                (dd->ipath_pio4kbase +
-                                                 (i - dd->ipath_piobcnt2k) *
-                                                 dd->ipath_4kalign);
-
-                                ipath_cdbg(PKT,
-                                           "PIObuf[%u] @%p pbc is %x; ",
-                                           i, piobuf, readl(piobuf));
-
-                                ipath_disarm_piobufs(dd, i, 1);
-                        }
-                }
-                if (ipath_debug & __IPATH_PKTDBG)
-                        printk("\n");
-        }
+        ipath_disarm_senderrbufs(dd);
         if ((errs & E_SUM_LINK_PKTERRS) &&
             !(dd->ipath_flags & IPATH_LINKACTIVE)) {
                 /*
@@ -554,6 +554,14 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
                         ~(INFINIPATH_E_HARDWARE |
                           INFINIPATH_E_IBSTATUSCHANGED);
         }
+
+        /* likely due to cancel, so suppress */
+        if ((errs & (INFINIPATH_E_SPKTLEN | INFINIPATH_E_SPIOARMLAUNCH)) &&
+                dd->ipath_lastcancel > jiffies) {
+                ipath_dbg("Suppressed armlaunch/spktlen after error send cancel\n");
+                errs &= ~(INFINIPATH_E_SPIOARMLAUNCH | INFINIPATH_E_SPKTLEN);
+        }
+
         if (!errs)
                 return 0;
 
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index 02134cb3e944..d7540b71b451 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -427,6 +427,9 @@ struct ipath_devdata {
         unsigned long ipath_rcvctrl;
         /* shadow kr_sendctrl */
         unsigned long ipath_sendctrl;
+        /* ports waiting for PIOavail intr */
+        unsigned long ipath_portpiowait;
+        unsigned long ipath_lastcancel; /* to not count armlaunch after cancel */
 
         /* value we put in kr_rcvhdrcnt */
         u32 ipath_rcvhdrcnt;
@@ -490,8 +493,6 @@ struct ipath_devdata {
         u32 ipath_htwidth;
         /* HT speed (200,400,800,1000) from HT config */
         u32 ipath_htspeed;
-        /* ports waiting for PIOavail intr */
-        unsigned long ipath_portpiowait;
         /*
          * number of sequential ibcstatus change for polling active/quiet
          * (i.e., link not coming up).
@@ -585,6 +586,7 @@ int ipath_enable_wc(struct ipath_devdata *dd);
 void ipath_disable_wc(struct ipath_devdata *dd);
 int ipath_count_units(int *npresentp, int *nupp, u32 *maxportsp);
 void ipath_shutdown_device(struct ipath_devdata *);
+void ipath_disarm_senderrbufs(struct ipath_devdata *);
 
 struct file_operations;
 int ipath_cdev_init(int minor, char *name, struct file_operations *fops,