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>

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 */

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;
 

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))]);

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;
 };