IB/ipath: Workaround problem of errormask register being overwritten

On some system hardware, we are seeing moderately common cases of the
chip errormask register being overwritten due to a chip bug in iba6120
that is triggered by a vendor-specific PCIe broadcast message.  This
patch merely checks periodically, and corrects it if needed (the
overwrite can cause us to not get error and hardware error
interrupts).  Also, make dd->ipath_errormask the one, true canonical
source for kr_errormask, and remove references to ipath_ignorederrs as
it is currently unused.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: John Gregor <john.gregor@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

4 files changed, 66 insertions, 29 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 71e6c9d4a714..9dd0bacf8461 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -851,13 +851,14 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
         ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrmask,
                          dd->ipath_hwerrmask);
 
-        dd->ipath_maskederrs = dd->ipath_ignorederrs;
         /* clear all */
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear, -1LL);
         /* enable errors that are masked, at least this first time. */
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
                          ~dd->ipath_maskederrs);
-        /* clear any interrups up to this point (ints still not enabled) */
+        dd->ipath_errormask = ipath_read_kreg64(dd,
+                dd->ipath_kregs->kr_errormask);
+        /* clear any interrupts up to this point (ints still not enabled) */
         ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, -1LL);
 
         /*
diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index 0c075cf8316b..b29fe7e9b11a 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -517,10 +517,7 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
 
         supp_msgs = handle_frequent_errors(dd, errs, msg, &noprint);
 
-        /*
-         * don't report errors that are masked (includes those always
-         * ignored)
-         */
+        /* don't report errors that are masked */
         errs &= ~dd->ipath_maskederrs;
 
         /* do these first, they are most important */
@@ -566,19 +563,19 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
                  * ones on this particular interrupt, which also isn't great
                  */
                 dd->ipath_maskederrs |= dd->ipath_lasterror | errs;
+                dd->ipath_errormask &= ~dd->ipath_maskederrs;
                 ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
-                                 ~dd->ipath_maskederrs);
+                        dd->ipath_errormask);
                 s_iserr = ipath_decode_err(msg, sizeof msg,
-                                 (dd->ipath_maskederrs & ~dd->
-                                  ipath_ignorederrs));
+                        dd->ipath_maskederrs);
 
-                if ((dd->ipath_maskederrs & ~dd->ipath_ignorederrs) &
+                if (dd->ipath_maskederrs &
                         ~(INFINIPATH_E_RRCVEGRFULL |
                         INFINIPATH_E_RRCVHDRFULL | INFINIPATH_E_PKTERRS))
                         ipath_dev_err(dd, "Temporarily disabling "
                             "error(s) %llx reporting; too frequent (%s)\n",
-                                (unsigned long long) (dd->ipath_maskederrs &
-                                ~dd->ipath_ignorederrs), msg);
+                                (unsigned long long)dd->ipath_maskederrs,
+                                msg);
                 else {
                         /*
                          * rcvegrfull and rcvhdrqfull are "normal",
@@ -793,6 +790,9 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
         /* disable error interrupts, to avoid confusion */
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
 
+        /* also disable interrupts; errormask is sometimes overwriten */
+        ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);
+
         /*
          * clear all sends, because they have may been
          * completed by usercode while in freeze mode, and
@@ -817,7 +817,7 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
         for (i = 0; i < dd->ipath_pioavregs; i++) {
                 /* deal with 6110 chip bug */
                 im = i > 3 ? ((i&1) ? i-1 : i+1) : i;
-                val = ipath_read_kreg64(dd, 0x1000+(im*sizeof(u64)));
+                val = ipath_read_kreg64(dd, (0x1000/sizeof(u64))+im);
                 dd->ipath_pioavailregs_dma[i] = dd->ipath_pioavailshadow[i]
                         = le64_to_cpu(val);
         }
@@ -832,7 +832,8 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear,
                 E_SPKT_ERRS_IGNORE);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
-                ~dd->ipath_maskederrs);
+                dd->ipath_errormask);
+        ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, -1LL);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, 0ULL);
 }
 
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index ef773298b805..7a7966f7e4ff 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -261,18 +261,10 @@ struct ipath_devdata {
          * limiting of hwerror reporting
          */
         ipath_err_t ipath_lasthwerror;
-        /*
-         * errors masked because they occur too fast, also includes errors
-         * that are always ignored (ipath_ignorederrs)
-         */
+        /* errors masked because they occur too fast */
         ipath_err_t ipath_maskederrs;
         /* time in jiffies at which to re-enable maskederrs */
         unsigned long ipath_unmasktime;
-        /*
-         * errors always ignored (masked), at least for a given
-         * chip/device, because they are wrong or not useful
-         */
-        ipath_err_t ipath_ignorederrs;
         /* count of egrfull errors, combined for all ports */
         u64 ipath_last_tidfull;
         /* for ipath_qcheck() */
@@ -436,6 +428,7 @@ struct ipath_devdata {
         u64 ipath_lastibcstat;
         /* hwerrmask shadow */
         ipath_err_t ipath_hwerrmask;
+        ipath_err_t ipath_errormask; /* errormask shadow */
         /* interrupt config reg shadow */
         u64 ipath_intconfig;
         /* kr_sendpiobufbase value */
diff --git a/drivers/infiniband/hw/ipath/ipath_stats.c b/drivers/infiniband/hw/ipath/ipath_stats.c
index 73ed17d03188..bae4f56f7271 100644
--- a/drivers/infiniband/hw/ipath/ipath_stats.c
+++ b/drivers/infiniband/hw/ipath/ipath_stats.c
@@ -196,6 +196,45 @@ static void ipath_qcheck(struct ipath_devdata *dd)
         }
 }
 
+static void ipath_chk_errormask(struct ipath_devdata *dd)
+{
+        static u32 fixed;
+        u32 ctrl;
+        unsigned long errormask;
+        unsigned long hwerrs;
+
+        if (!dd->ipath_errormask || !(dd->ipath_flags & IPATH_INITTED))
+                return;
+
+        errormask = ipath_read_kreg64(dd, dd->ipath_kregs->kr_errormask);
+
+        if (errormask == dd->ipath_errormask)
+                return;
+        fixed++;
+
+        hwerrs = ipath_read_kreg64(dd, dd->ipath_kregs->kr_hwerrstatus);
+        ctrl = ipath_read_kreg32(dd, dd->ipath_kregs->kr_control);
+
+        ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
+                dd->ipath_errormask);
+
+        if ((hwerrs & dd->ipath_hwerrmask) ||
+                (ctrl & INFINIPATH_C_FREEZEMODE)) {
+                /* force re-interrupt of pending events, just in case */
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear, 0ULL);
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear, 0ULL);
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, 0ULL);
+                dev_info(&dd->pcidev->dev,
+                        "errormask fixed(%u) %lx -> %lx, ctrl %x hwerr %lx\n",
+                        fixed, errormask, (unsigned long)dd->ipath_errormask,
+                        ctrl, hwerrs);
+        } else
+                ipath_dbg("errormask fixed(%u) %lx -> %lx, no freeze\n",
+                        fixed, errormask,
+                        (unsigned long)dd->ipath_errormask);
+}
+
+
 /**
  * ipath_get_faststats - get word counters from chip before they overflow
  * @opaque - contains a pointer to the infinipath device ipath_devdata
@@ -251,14 +290,13 @@ void ipath_get_faststats(unsigned long opaque)
                 dd->ipath_lasterror = 0;
         if (dd->ipath_lasthwerror)
                 dd->ipath_lasthwerror = 0;
-        if ((dd->ipath_maskederrs & ~dd->ipath_ignorederrs)
+        if (dd->ipath_maskederrs
             && time_after(jiffies, dd->ipath_unmasktime)) {
                 char ebuf[256];
                 int iserr;
                 iserr = ipath_decode_err(ebuf, sizeof ebuf,
-                                 (dd->ipath_maskederrs & ~dd->
-                                  ipath_ignorederrs));
-                if ((dd->ipath_maskederrs & ~dd->ipath_ignorederrs) &
+                        dd->ipath_maskederrs);
+                if (dd->ipath_maskederrs &
                                 ~(INFINIPATH_E_RRCVEGRFULL | INFINIPATH_E_RRCVHDRFULL |
                                 INFINIPATH_E_PKTERRS ))
                         ipath_dev_err(dd, "Re-enabling masked errors "
@@ -278,9 +316,12 @@ void ipath_get_faststats(unsigned long opaque)
                                 ipath_cdbg(ERRPKT, "Re-enabling packet"
                                                 " problem interrupt (%s)\n", ebuf);
                 }
-                dd->ipath_maskederrs = dd->ipath_ignorederrs;
+
+                /* re-enable masked errors */
+                dd->ipath_errormask |= dd->ipath_maskederrs;
                 ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
-                                 ~dd->ipath_maskederrs);
+                        dd->ipath_errormask);
+                dd->ipath_maskederrs = 0;
         }
 
         /* limit qfull messages to ~one per minute per port */
@@ -294,6 +335,7 @@ void ipath_get_faststats(unsigned long opaque)
                 }
         }
 
+        ipath_chk_errormask(dd);
 done:
         mod_timer(&dd->ipath_stats_timer, jiffies + HZ * 5);
 }