RDMA/qedr: iWARP invalid(zero) doorbell address fix

This patch fixes issue introduced by a previous commit where iWARP
doorbell address wasn't initialized, causing call trace when any RDMA
application wants to use this interface:

  Illegal doorbell address: 0000000000000000. Legal range for doorbell addresses is [0000000011431e08..00000000ec3799d3]
  WARNING: CPU: 11 PID: 11990 at drivers/net/ethernet/qlogic/qed/qed_dev.c:93 qed_db_rec_sanity.isra.12+0x48/0x70 [qed]
  ...
   hpsa scsi_transport_sas [last unloaded: crc8]
  CPU: 11 PID: 11990 Comm: rping Tainted: G S                5.10.0-rc1 #29
  Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 01/22/2018
  RIP: 0010:qed_db_rec_sanity.isra.12+0x48/0x70 [qed]
  ...
  RSP: 0018:ffffafc28458fa88 EFLAGS: 00010286
  RAX: 0000000000000000 RBX: ffff8d0d4c620000 RCX: 0000000000000000
  RDX: ffff8d10afde7d50 RSI: ffff8d10afdd8b40 RDI: ffff8d10afdd8b40
  RBP: ffffafc28458fe38 R08: 0000000000000003 R09: 0000000000007fff
  R10: 0000000000000001 R11: ffffafc28458f888 R12: 0000000000000000
  R13: 0000000000000000 R14: ffff8d0d43ccbbd0 R15: ffff8d0d48dae9c0
  FS:  00007fbd5267e740(0000) GS:ffff8d10afdc0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fbd4f258fb8 CR3: 0000000108d96003 CR4: 00000000001706e0
  Call Trace:
   qed_db_recovery_add+0x6d/0x1f0 [qed]
   qedr_create_user_qp+0x57e/0xd30 [qedr]
   qedr_create_qp+0x5f3/0xab0 [qedr]
   ? lookup_get_idr_uobject.part.12+0x45/0x90 [ib_uverbs]
   create_qp+0x45d/0xb30 [ib_uverbs]
   ? ib_uverbs_cq_event_handler+0x30/0x30 [ib_uverbs]
   ib_uverbs_create_qp+0xb9/0xe0 [ib_uverbs]
   ib_uverbs_write+0x3f9/0x570 [ib_uverbs]
   ? security_mmap_file+0x62/0xe0
   vfs_write+0xb7/0x200
   ksys_write+0xaf/0xd0
   ? syscall_trace_enter.isra.25+0x152/0x200
   do_syscall_64+0x2d/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 06e8d1d ("RDMA/qedr: Add support for user mode XRC-SRQ's")
Link: https://lore.kernel.org/r/20201127163251.14533-1-palok@marvell.com
Signed-off-by: Michal Kalderon <mkalderon@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Alok Prasad <palok@marvell.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/qedr/verbs.c

@@ -1936,6 +1936,15 @@ static int qedr_create_user_qp(struct qedr_dev *dev,
 	}
 
 	if (rdma_protocol_iwarp(&dev->ibdev, 1)) {
+		qp->urq.db_rec_db2_addr = ctx->dpi_addr + uresp.rq_db2_offset;
+
+		/* calculate the db_rec_db2 data since it is constant so no
+		 * need to reflect from user
+		 */
+		qp->urq.db_rec_db2_data.data.icid = cpu_to_le16(qp->icid);
+		qp->urq.db_rec_db2_data.data.value =
+			cpu_to_le16(DQ_TCM_IWARP_POST_RQ_CF_CMD);
+
 		rc = qedr_db_recovery_add(dev, qp->urq.db_rec_db2_addr,
 					  &qp->urq.db_rec_db2_data,
 					  DB_REC_WIDTH_32B,