IB/ipath: Add ability to set and clear IB local loopback

This is a sticky state.  It is useful for diagnosing problems with
boards versus cable/switch problems.

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

2 files changed, 18 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_common.h b/drivers/infiniband/hw/ipath/ipath_common.h
index 54139d398181..a41367803529 100644
--- a/drivers/infiniband/hw/ipath/ipath_common.h
+++ b/drivers/infiniband/hw/ipath/ipath_common.h
@@ -78,6 +78,8 @@
 #define IPATH_IB_LINKINIT               3
 #define IPATH_IB_LINKDOWN_SLEEP         4
 #define IPATH_IB_LINKDOWN_DISABLE       5
+#define IPATH_IB_LINK_LOOPBACK  6 /* enable local loopback */
+#define IPATH_IB_LINK_EXTERNAL  7 /* normal, disable local loopback */
 
 /*
  * stats maintained by the driver.  For now, at least, this is global
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index ae7f21a0cdc0..c2fe5417ff45 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -1662,6 +1662,22 @@ int ipath_set_linkstate(struct ipath_devdata *dd, u8 newstate)
                 lstate = IPATH_LINKACTIVE;
                 break;
 
+        case IPATH_IB_LINK_LOOPBACK:
+                dev_info(&dd->pcidev->dev, "Enabling IB local loopback\n");
+                dd->ipath_ibcctrl |= INFINIPATH_IBCC_LOOPBACK;
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
+                                 dd->ipath_ibcctrl);
+                ret = 0;
+                goto bail; // no state change to wait for
+
+        case IPATH_IB_LINK_EXTERNAL:
+                dev_info(&dd->pcidev->dev, "Disabling IB local loopback (normal)\n");
+                dd->ipath_ibcctrl &= ~INFINIPATH_IBCC_LOOPBACK;
+                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
+                                 dd->ipath_ibcctrl);
+                ret = 0;
+                goto bail; // no state change to wait for
+
         default:
                 ipath_dbg("Invalid linkstate 0x%x requested\n", newstate);
                 ret = -EINVAL;