[SCSI] ibmvfc: Add support for NPIV Logout

This patch adds support for a new command supported by the Virtual I/O
Server, NPIV Logout. The command will abort all outstanding commands
and log out of the fabric. Currently, the only way to do this is
by breaking the CRQ, which can take a fairly long time when lots of
commands are outstanding. The NPIV Logout commands provides a mechanism
to accomplish virtually the same function, but is much faster.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 94 insertions, 3 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 76ae266b07c4..6eb3b75eec93 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -143,6 +143,7 @@ static void ibmvfc_npiv_login(struct ibmvfc_host *);
 static void ibmvfc_tgt_send_prli(struct ibmvfc_target *);
 static void ibmvfc_tgt_send_plogi(struct ibmvfc_target *);
 static void ibmvfc_tgt_query_target(struct ibmvfc_target *);
+static void ibmvfc_npiv_logout(struct ibmvfc_host *);
 
 static const char *unknown_error = "unknown error";
 
@@ -477,6 +478,10 @@ static void ibmvfc_set_host_action(struct ibmvfc_host *vhost,
                 if (vhost->action == IBMVFC_HOST_ACTION_INIT_WAIT)
                         vhost->action = action;
                 break;
+        case IBMVFC_HOST_ACTION_LOGO_WAIT:
+                if (vhost->action == IBMVFC_HOST_ACTION_LOGO)
+                        vhost->action = action;
+                break;
         case IBMVFC_HOST_ACTION_INIT_WAIT:
                 if (vhost->action == IBMVFC_HOST_ACTION_INIT)
                         vhost->action = action;
@@ -496,6 +501,7 @@ static void ibmvfc_set_host_action(struct ibmvfc_host *vhost,
                 if (vhost->action == IBMVFC_HOST_ACTION_ALLOC_TGTS)
                         vhost->action = action;
                 break;
+        case IBMVFC_HOST_ACTION_LOGO:
         case IBMVFC_HOST_ACTION_INIT:
         case IBMVFC_HOST_ACTION_TGT_DEL:
         case IBMVFC_HOST_ACTION_QUERY_TGTS:
@@ -647,6 +653,7 @@ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost)
         } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
 
         vhost->state = IBMVFC_NO_CRQ;
+        vhost->logged_in = 0;
         dma_unmap_single(vhost->dev, crq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
         free_page((unsigned long)crq->msgs);
 }
@@ -693,6 +700,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
         } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
 
         vhost->state = IBMVFC_NO_CRQ;
+        vhost->logged_in = 0;
         ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);
 
         /* Clean out the queue */
@@ -808,10 +816,10 @@ static void ibmvfc_purge_requests(struct ibmvfc_host *vhost, int error_code)
 }
 
 /**
- * __ibmvfc_reset_host - Reset the connection to the server (no locking)
+ * ibmvfc_hard_reset_host - Reset the connection to the server by breaking the CRQ
  * @vhost:      struct ibmvfc host to reset
  **/
-static void __ibmvfc_reset_host(struct ibmvfc_host *vhost)
+static void ibmvfc_hard_reset_host(struct ibmvfc_host *vhost)
 {
         int rc;
 
@@ -827,9 +835,25 @@ static void __ibmvfc_reset_host(struct ibmvfc_host *vhost)
 }
 
 /**
- * ibmvfc_reset_host - Reset the connection to the server
+ * __ibmvfc_reset_host - Reset the connection to the server (no locking)
  * @vhost:      struct ibmvfc host to reset
  **/
+static void __ibmvfc_reset_host(struct ibmvfc_host *vhost)
+{
+        if (vhost->logged_in && vhost->action != IBMVFC_HOST_ACTION_LOGO_WAIT &&
+            !ibmvfc_set_host_state(vhost, IBMVFC_INITIALIZING)) {
+                scsi_block_requests(vhost->host);
+                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_LOGO);
+                vhost->job_step = ibmvfc_npiv_logout;
+                wake_up(&vhost->work_wait_q);
+        } else
+                ibmvfc_hard_reset_host(vhost);
+}
+
+/**
+ * ibmvfc_reset_host - Reset the connection to the server
+ * @vhost:      ibmvfc host struct
+ **/
 static void ibmvfc_reset_host(struct ibmvfc_host *vhost)
 {
         unsigned long flags;
@@ -2230,6 +2254,7 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
                 return;
         case IBMVFC_CRQ_XPORT_EVENT:
                 vhost->state = IBMVFC_NO_CRQ;
+                vhost->logged_in = 0;
                 ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);
                 if (crq->format == IBMVFC_PARTITION_MIGRATED) {
                         /* We need to re-setup the interpartition connection */
@@ -3554,6 +3579,7 @@ static void ibmvfc_npiv_login_done(struct ibmvfc_event *evt)
                 return;
         }
 
+        vhost->logged_in = 1;
         npiv_max_sectors = min((uint)(rsp->max_dma_len >> 9), IBMVFC_MAX_SECTORS);
         dev_info(vhost->dev, "Host partition: %s, device: %s %s %s max sectors %u\n",
                  rsp->partition_name, rsp->device_name, rsp->port_loc_code,
@@ -3612,6 +3638,65 @@ static void ibmvfc_npiv_login(struct ibmvfc_host *vhost)
 };
 
 /**
+ * ibmvfc_npiv_logout_done - Completion handler for NPIV Logout
+ * @vhost:              ibmvfc host struct
+ *
+ **/
+static void ibmvfc_npiv_logout_done(struct ibmvfc_event *evt)
+{
+        struct ibmvfc_host *vhost = evt->vhost;
+        u32 mad_status = evt->xfer_iu->npiv_logout.common.status;
+
+        ibmvfc_free_event(evt);
+
+        switch (mad_status) {
+        case IBMVFC_MAD_SUCCESS:
+                if (list_empty(&vhost->sent) &&
+                    vhost->action == IBMVFC_HOST_ACTION_LOGO_WAIT) {
+                        ibmvfc_init_host(vhost, 0);
+                        return;
+                }
+                break;
+        case IBMVFC_MAD_FAILED:
+        case IBMVFC_MAD_NOT_SUPPORTED:
+        case IBMVFC_MAD_CRQ_ERROR:
+        case IBMVFC_MAD_DRIVER_FAILED:
+        default:
+                ibmvfc_dbg(vhost, "NPIV Logout failed. 0x%X\n", mad_status);
+                break;
+        }
+
+        ibmvfc_hard_reset_host(vhost);
+}
+
+/**
+ * ibmvfc_npiv_logout - Issue an NPIV Logout
+ * @vhost:              ibmvfc host struct
+ *
+ **/
+static void ibmvfc_npiv_logout(struct ibmvfc_host *vhost)
+{
+        struct ibmvfc_npiv_logout_mad *mad;
+        struct ibmvfc_event *evt;
+
+        evt = ibmvfc_get_event(vhost);
+        ibmvfc_init_event(evt, ibmvfc_npiv_logout_done, IBMVFC_MAD_FORMAT);
+
+        mad = &evt->iu.npiv_logout;
+        memset(mad, 0, sizeof(*mad));
+        mad->common.version = 1;
+        mad->common.opcode = IBMVFC_NPIV_LOGOUT;
+        mad->common.length = sizeof(struct ibmvfc_npiv_logout_mad);
+
+        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_LOGO_WAIT);
+
+        if (!ibmvfc_send_event(evt, vhost, default_timeout))
+                ibmvfc_dbg(vhost, "Sent NPIV logout\n");
+        else
+                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
+}
+
+/**
  * ibmvfc_dev_init_to_do - Is there target initialization work to do?
  * @vhost:              ibmvfc host struct
  *
@@ -3647,6 +3732,7 @@ static int __ibmvfc_work_to_do(struct ibmvfc_host *vhost)
         switch (vhost->action) {
         case IBMVFC_HOST_ACTION_NONE:
         case IBMVFC_HOST_ACTION_INIT_WAIT:
+        case IBMVFC_HOST_ACTION_LOGO_WAIT:
                 return 0;
         case IBMVFC_HOST_ACTION_TGT_INIT:
         case IBMVFC_HOST_ACTION_QUERY_TGTS:
@@ -3659,6 +3745,7 @@ static int __ibmvfc_work_to_do(struct ibmvfc_host *vhost)
                         if (tgt->action == IBMVFC_TGT_ACTION_INIT_WAIT)
                                 return 0;
                 return 1;
+        case IBMVFC_HOST_ACTION_LOGO:
         case IBMVFC_HOST_ACTION_INIT:
         case IBMVFC_HOST_ACTION_ALLOC_TGTS:
         case IBMVFC_HOST_ACTION_TGT_DEL:
@@ -3765,8 +3852,12 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost)
         vhost->events_to_log = 0;
         switch (vhost->action) {
         case IBMVFC_HOST_ACTION_NONE:
+        case IBMVFC_HOST_ACTION_LOGO_WAIT:
         case IBMVFC_HOST_ACTION_INIT_WAIT:
                 break;
+        case IBMVFC_HOST_ACTION_LOGO:
+                vhost->job_step(vhost);
+                break;
         case IBMVFC_HOST_ACTION_INIT:
                 BUG_ON(vhost->state != IBMVFC_INITIALIZING);
                 if (vhost->delay_init) {