IB/ipath: Fix driver crash (in interrupt or during unload) after chip reset

Re-init of the kernel structures after a chip reset was leaving the
portdata structure for port zero in an inconsistent state, and a
pointer to it either stale (in re-init code) or NULL (in devdata)
Fixing the order of operations on this struct, and the condition for
interrupt access, prevents the crashes.

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

2 files changed, 35 insertions, 12 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 72caa9f091f6..7045ba689494 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -216,6 +216,20 @@ static int bringup_link(struct ipath_devdata *dd)
         return ret;
 }
 
+static struct ipath_portdata *create_portdata0(struct ipath_devdata *dd)
+{
+        struct ipath_portdata *pd = NULL;
+
+        pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+        if (pd) {
+                pd->port_dd = dd;
+                pd->port_cnt = 1;
+                /* The port 0 pkey table is used by the layer interface. */
+                pd->port_pkeys[0] = IPATH_DEFAULT_P_KEY;
+        }
+        return pd;
+}
+
 static int init_chip_first(struct ipath_devdata *dd,
                            struct ipath_portdata **pdp)
 {
@@ -271,20 +285,16 @@ static int init_chip_first(struct ipath_devdata *dd,
                 goto done;
         }
 
-        dd->ipath_pd[0] = kzalloc(sizeof(*pd), GFP_KERNEL);
+        pd = create_portdata0(dd);
 
-        if (!dd->ipath_pd[0]) {
+        if (!pd) {
                 ipath_dev_err(dd, "Unable to allocate portdata for port "
                               "0, failing\n");
                 ret = -ENOMEM;
                 goto done;
         }
-        pd = dd->ipath_pd[0];
-        pd->port_dd = dd;
-        pd->port_port = 0;
-        pd->port_cnt = 1;
-        /* The port 0 pkey table is used by the layer interface. */
-        pd->port_pkeys[0] = IPATH_DEFAULT_P_KEY;
+        dd->ipath_pd[0] = pd;
+
         dd->ipath_rcvtidcnt =
                 ipath_read_kreg32(dd, dd->ipath_kregs->kr_rcvtidcnt);
         dd->ipath_rcvtidbase =
@@ -838,11 +848,24 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
          * Set up the port 0 (kernel) rcvhdr q and egr TIDs.  If doing
          * re-init, the simplest way to handle this is to free
          * existing, and re-allocate.
+         * Need to re-create rest of port 0 portdata as well.
          */
         if (reinit) {
-                struct ipath_portdata *pd = dd->ipath_pd[0];
-                dd->ipath_pd[0] = NULL;
-                ipath_free_pddata(dd, pd);
+                /* Alloc and init new ipath_portdata for port0,
+                 * Then free old pd. Could lead to fragmentation, but also
+                 * makes later support for hot-swap easier.
+                 */
+                struct ipath_portdata *npd;
+                npd = create_portdata0(dd);
+                if (npd) {
+                        ipath_free_pddata(dd, pd);
+                        dd->ipath_pd[0] = pd = npd;
+                } else {
+                        ipath_dev_err(dd, "Unable to allocate portdata for"
+                                      "  port 0, failing\n");
+                        ret = -ENOMEM;
+                        goto done;
+                }
         }
         dd->ipath_f_tidtemplate(dd);
         ret = ipath_create_rcvhdrq(dd, pd);
diff --git a/drivers/infiniband/hw/ipath/ipath_stats.c b/drivers/infiniband/hw/ipath/ipath_stats.c
index a627342a969c..9307f7187ca5 100644
--- a/drivers/infiniband/hw/ipath/ipath_stats.c
+++ b/drivers/infiniband/hw/ipath/ipath_stats.c
@@ -207,7 +207,7 @@ void ipath_get_faststats(unsigned long opaque)
          * don't access the chip while running diags, or memory diags can
          * fail
          */
-        if (!dd->ipath_kregbase || !(dd->ipath_flags & IPATH_PRESENT) ||
+        if (!dd->ipath_kregbase || !(dd->ipath_flags & IPATH_INITTED) ||
             ipath_diag_inuse)
                 /* but re-arm the timer, for diags case; won't hurt other */
                 goto done;