1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index ab118558552..4089f862aa2 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -334,6 +334,8 @@ static int gru_try_dropin(struct gru_thread_state *gts,
          * Might be a hardware race OR a stupid user. Ignore FMM because FMM
          * is a transient state.
          */
+        if (tfh->status != TFHSTATUS_EXCEPTION)
+                goto failnoexception;
         if (tfh->state == TFHSTATE_IDLE)
                 goto failidle;
         if (tfh->state == TFHSTATE_MISS_FMM && cb)
@@ -401,8 +403,17 @@ failfmm:
         gru_dbg(grudev, "FAILED fmm tfh: 0x%p, state %d\n", tfh, tfh->state);
         return 0;
 
+failnoexception:
+        /* TFH status did not show exception pending */
+        gru_flush_cache(tfh);
+        if (cb)
+                gru_flush_cache(cb);
+        STAT(tlb_dropin_fail_no_exception);
+        gru_dbg(grudev, "FAILED non-exception tfh: 0x%p, status %d, state %d\n", tfh, tfh->status, tfh->state);
+        return 0;
+
 failidle:
-        /* TFH was idle  - no miss pending */
+        /* TFH state was idle  - no miss pending */
         gru_flush_cache(tfh);
         if (cb)
                 gru_flush_cache(cb);
@@ -472,7 +483,8 @@ irqreturn_t gru_intr(int irq, void *dev_id)
                  * This is running in interrupt context. Trylock the mmap_sem.
                  * If it fails, retry the fault in user context.
                  */
-                if (down_read_trylock(&gts->ts_mm->mmap_sem)) {
+                if (!gts->ts_force_cch_reload &&
+                                        down_read_trylock(&gts->ts_mm->mmap_sem)) {
                         gru_try_dropin(gts, tfh, NULL);
                         up_read(&gts->ts_mm->mmap_sem);
                 } else {
@@ -595,14 +607,19 @@ int gru_get_exception_detail(unsigned long arg)
                 excdet.ecause = cbe->ecause;
                 excdet.exceptdet0 = cbe->idef1upd;
                 excdet.exceptdet1 = cbe->idef3upd;
+                excdet.cbrstate = cbe->cbrstate;
+                excdet.cbrexecstatus = cbe->cbrexecstatus;
                 ret = 0;
         } else {
                 ret = -EAGAIN;
         }
         gru_unlock_gts(gts);
 
-        gru_dbg(grudev, "address 0x%lx, ecause 0x%x\n", excdet.cb,
-                excdet.ecause);
+        gru_dbg(grudev,
+                "cb 0x%lx, op %d, exopc %d, cbrstate %d, cbrexecstatus 0x%x, ecause 0x%x, "
+                "exdet0 0x%lx, exdet1 0x%x\n",
+                excdet.cb, excdet.opc, excdet.exopc, excdet.cbrstate, excdet.cbrexecstatus,
+                excdet.ecause, excdet.exceptdet0, excdet.exceptdet1);
         if (!ret && copy_to_user((void __user *)arg, &excdet, sizeof(excdet)))
                 ret = -EFAULT;
         return ret;