IB/ipath: Fix sendctrl locking

Code review pointed out that the locking around uses of ipath_sendctrl 
and kr_sendctrl were, in several places, incorrect and/or inconsistent.

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

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index ad41cccd2e9f..eac2e9c55281 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -795,6 +795,7 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
 {
         int i, im;
         __le64 val;
+        unsigned long flags;
 
         /* disable error interrupts, to avoid confusion */
         ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
@@ -813,11 +814,14 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
                          dd->ipath_control);
 
         /* ensure pio avail updates continue */
+        spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
                  dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);
         ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-                 dd->ipath_sendctrl);
+                         dd->ipath_sendctrl);
+        ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+        spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
 
         /*
          * We just enabled pioavailupdate, so dma copy is almost certainly
@@ -922,6 +926,7 @@ static noinline void ipath_bad_regread(struct ipath_devdata *dd)
 
 static void handle_layer_pioavail(struct ipath_devdata *dd)
 {
+        unsigned long flags;
         int ret;
 
         ret = ipath_ib_piobufavail(dd->verbs_dev);
@@ -930,9 +935,12 @@ static void handle_layer_pioavail(struct ipath_devdata *dd)
 
         return;
 set:
-        set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
+        spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+        dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
         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);
 }
 
 /*
@@ -1168,9 +1176,14 @@ irqreturn_t ipath_intr(int irq, void *data)
                 handle_urcv(dd, istat);
 
         if (istat & INFINIPATH_I_SPIOBUFAVAIL) {
-                clear_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
+                unsigned long flags;
+
+                spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+                dd->ipath_sendctrl &= ~INFINIPATH_S_PIOINTBUFAVAIL;
                 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);
 
                 handle_layer_pioavail(dd);
         }