RDMA/core: Add local DMA L_Key support

- Change the IB_DEVICE_ZERO_STAG flag to the transport-neutral name
  IB_DEVICE_LOCAL_DMA_LKEY, which is used by iWARP RNICs to indicate 0
  STag support and IB HCAs to indicate reserved L_Key support.

- Add a u32 local_dma_lkey member to struct ib_device.  Drivers fill
  this in with the appropriate local DMA L_Key (if they support it).

- Fix up the drivers using this flag.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

4 files changed, 8 insertions, 5 deletions

diff --git a/drivers/infiniband/hw/amso1100/c2_rnic.c b/drivers/infiniband/hw/amso1100/c2_rnic.c
index b1441aeb60c2..dd05c4835642 100644
--- a/drivers/infiniband/hw/amso1100/c2_rnic.c
+++ b/drivers/infiniband/hw/amso1100/c2_rnic.c
@@ -454,7 +454,7 @@ int __devinit c2_rnic_init(struct c2_dev *c2dev)
             (IB_DEVICE_RESIZE_MAX_WR |
              IB_DEVICE_CURR_QP_STATE_MOD |
              IB_DEVICE_SYS_IMAGE_GUID |
-             IB_DEVICE_ZERO_STAG |
+             IB_DEVICE_LOCAL_DMA_LKEY |
              IB_DEVICE_MEM_WINDOW);
 
         /* Allocate the qptr_array */
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.c b/drivers/infiniband/hw/cxgb3/iwch_provider.c
index c9a3893b38e8..7ecfd4d638c5 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c
@@ -1325,8 +1325,10 @@ int iwch_register_device(struct iwch_dev *dev)
         memset(&dev->ibdev.node_guid, 0, sizeof(dev->ibdev.node_guid));
         memcpy(&dev->ibdev.node_guid, dev->rdev.t3cdev_p->lldev->dev_addr, 6);
         dev->ibdev.owner = THIS_MODULE;
-        dev->device_cap_flags = IB_DEVICE_ZERO_STAG |
-                                IB_DEVICE_MEM_WINDOW;
+        dev->device_cap_flags = IB_DEVICE_LOCAL_DMA_LKEY | IB_DEVICE_MEM_WINDOW;
+
+        /* cxgb3 supports STag 0. */
+        dev->ibdev.local_dma_lkey = 0;
         if (fw_supports_fastreg(dev))
                 dev->device_cap_flags |= IB_DEVICE_MEM_MGT_EXTENSIONS;
 
diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 902b1375a5d8..85f26d19a32b 100644
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -398,7 +398,7 @@ struct nes_adapter *nes_init_adapter(struct nes_device *nesdev, u8 hw_rev) {
         nesadapter->base_pd = 1;
 
         nesadapter->device_cap_flags =
-                IB_DEVICE_ZERO_STAG | IB_DEVICE_MEM_WINDOW;
+                IB_DEVICE_LOCAL_DMA_LKEY | IB_DEVICE_MEM_WINDOW;
 
         nesadapter->allocated_qps = (unsigned long *)&(((unsigned char *)nesadapter)
                         [(sizeof(struct nes_adapter)+(sizeof(unsigned long)-1))&(~(sizeof(unsigned long)-1))]);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 07b41e05565a..90b529f7a154 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -91,7 +91,7 @@ enum ib_device_cap_flags {
         IB_DEVICE_RC_RNR_NAK_GEN        = (1<<12),
         IB_DEVICE_SRQ_RESIZE            = (1<<13),
         IB_DEVICE_N_NOTIFY_CQ           = (1<<14),
-        IB_DEVICE_ZERO_STAG             = (1<<15),
+        IB_DEVICE_LOCAL_DMA_LKEY        = (1<<15),
         IB_DEVICE_RESERVED              = (1<<16), /* old SEND_W_INV */
         IB_DEVICE_MEM_WINDOW            = (1<<17),
         /*
@@ -1149,6 +1149,7 @@ struct ib_device {
 
         char                         node_desc[64];
         __be64                       node_guid;
+        u32                          local_dma_lkey;
         u8                           node_type;
         u8                           phys_port_cnt;
 };