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;
 };