IB/srp: Add 64-bit LUN support

The SCSI standard defines 64-bit values for LUNs. Large arrays
employing large or hierarchical LUN numbers become more and more
common. So update the SRP initiator to use 64-bit LUN numbers.
See also Hannes Reinecke, commit 9cb78c16f5 ("scsi: use 64-bit LUNs"),
June 2014.

The largest LUN number that has been tested is 0xd2003fff00000000.

Checked the following structure sizes with gdb:
* sizeof(struct srp_cmd) = 48
* sizeof(struct srp_tsk_mgmt) = 48
* sizeof(struct srp_aer_req) = 36

The ibmvscsi changes have been compile tested only (on a PPC system).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -1832,7 +1832,7 @@ static void srp_process_aer_req(struct srp_rdma_ch *ch,
 	s32 delta = be32_to_cpu(req->req_lim_delta);
 
 	shost_printk(KERN_ERR, target->scsi_host, PFX
-		     "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
+		     "ignoring AER for LUN %llu\n", scsilun_to_int(&req->lun));
 
 	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
 		shost_printk(KERN_ERR, target->scsi_host, PFX
@@ -2024,7 +2024,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 	memset(cmd, 0, sizeof *cmd);
 
 	cmd->opcode = SRP_CMD;
-	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
+	int_to_scsilun(scmnd->device->lun, &cmd->lun);
 	cmd->tag    = tag;
 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
 
@@ -2404,8 +2404,8 @@ srp_change_queue_depth(struct scsi_device *sdev, int qdepth)
 	return scsi_change_queue_depth(sdev, qdepth);
 }
 
-static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag,
-			     unsigned int lun, u8 func)
+static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag, u64 lun,
+			     u8 func)
 {
 	struct srp_target_port *target = ch->target;
 	struct srp_rport *rport = target->rport;
@@ -2439,7 +2439,7 @@ static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag,
 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
 
 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
-	tsk_mgmt->lun		= cpu_to_be64((u64) lun << 48);
+	int_to_scsilun(lun, &tsk_mgmt->lun);
 	tsk_mgmt->tag		= req_tag | SRP_TAG_TSK_MGMT;
 	tsk_mgmt->tsk_mgmt_func = func;
 	tsk_mgmt->task_tag	= req_tag;
@@ -3134,7 +3134,7 @@ static ssize_t srp_create_target(struct device *dev,
 	target_host->transportt  = ib_srp_transport_template;
 	target_host->max_channel = 0;
 	target_host->max_id      = 1;
-	target_host->max_lun     = SRP_MAX_LUN;
+	target_host->max_lun     = -1LL;
 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
 
 	target = host_to_target(target_host);

drivers/infiniband/ulp/srp/ib_srp.h

@@ -54,7 +54,6 @@ enum {
 	SRP_DLID_REDIRECT	= 2,
 	SRP_STALE_CONN		= 3,
 
-	SRP_MAX_LUN		= 512,
 	SRP_DEF_SG_TABLESIZE	= 12,
 
 	SRP_DEFAULT_QUEUE_SIZE	= 1 << 6,