[SCSI] ibmvfc: Add flush on halt support

The virtual I/O server controlling the NPIV adapter associated with
a virtual fibre channel adapter can send a HALT event to the client.
When this occurs, the client can no longer send commands until a RESUME
is received. By adding support for flush on halt, we will get all of
our outstanding commands flushed back before the Virtual I/O server
enters the halt state, eliminating potential command timeouts for
outstanding commands which might occur if we did not support this feature.

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

2 files changed, 42 insertions, 5 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 6eb3b75eec93..04d97d9e3cea 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -110,7 +110,7 @@ static const struct {
         { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_DEAD, DID_ERROR, 0, 1, "transport dead" },
         { IBMVFC_FABRIC_MAPPED, IBMVFC_CONFIG_ERROR, DID_ERROR, 1, 1, "configuration error" },
         { IBMVFC_FABRIC_MAPPED, IBMVFC_NAME_SERVER_FAIL, DID_ERROR, 1, 1, "name server failure" },
-        { IBMVFC_FABRIC_MAPPED, IBMVFC_LINK_HALTED, DID_REQUEUE, 0, 0, "link halted" },
+        { IBMVFC_FABRIC_MAPPED, IBMVFC_LINK_HALTED, DID_REQUEUE, 1, 0, "link halted" },
         { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_GENERAL, DID_OK, 1, 0, "general transport error" },
 
         { IBMVFC_VIOS_FAILURE, IBMVFC_CRQ_FAILURE, DID_REQUEUE, 1, 1, "CRQ failure" },
@@ -1169,8 +1169,9 @@ static void ibmvfc_set_login_info(struct ibmvfc_host *vhost)
         login_info->partition_num = vhost->partition_number;
         login_info->vfc_frame_version = 1;
         login_info->fcp_version = 3;
+        login_info->flags = IBMVFC_FLUSH_ON_HALT;
         if (vhost->client_migrated)
-                login_info->flags = IBMVFC_CLIENT_MIGRATED;
+                login_info->flags |= IBMVFC_CLIENT_MIGRATED;
 
         login_info->max_cmds = max_requests + IBMVFC_NUM_INTERNAL_REQ;
         login_info->capabilities = IBMVFC_CAN_MIGRATE;
@@ -2185,8 +2186,25 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
                    " node_name: %llx\n", desc, crq->scsi_id, crq->wwpn, crq->node_name);
 
         switch (crq->event) {
-        case IBMVFC_AE_LINK_UP:
         case IBMVFC_AE_RESUME:
+                switch (crq->link_state) {
+                case IBMVFC_AE_LS_LINK_DOWN:
+                        ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
+                        break;
+                case IBMVFC_AE_LS_LINK_DEAD:
+                        ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
+                        break;
+                case IBMVFC_AE_LS_LINK_UP:
+                case IBMVFC_AE_LS_LINK_BOUNCED:
+                default:
+                        vhost->events_to_log |= IBMVFC_AE_LINKUP;
+                        vhost->delay_init = 1;
+                        __ibmvfc_reset_host(vhost);
+                        break;
+                };
+
+                break;
+        case IBMVFC_AE_LINK_UP:
                 vhost->events_to_log |= IBMVFC_AE_LINKUP;
                 vhost->delay_init = 1;
                 __ibmvfc_reset_host(vhost);
@@ -2505,6 +2523,14 @@ static ssize_t ibmvfc_show_host_npiv_version(struct device *dev,
         return snprintf(buf, PAGE_SIZE, "%d\n", vhost->login_buf->resp.version);
 }
 
+static ssize_t ibmvfc_show_host_capabilities(struct device *dev,
+                                             struct device_attribute *attr, char *buf)
+{
+        struct Scsi_Host *shost = class_to_shost(dev);
+        struct ibmvfc_host *vhost = shost_priv(shost);
+        return snprintf(buf, PAGE_SIZE, "%llx\n", vhost->login_buf->resp.capabilities);
+}
+
 /**
  * ibmvfc_show_log_level - Show the adapter's error logging level
  * @dev:        class device struct
@@ -2554,6 +2580,7 @@ static DEVICE_ATTR(device_name, S_IRUGO, ibmvfc_show_host_device_name, NULL);
 static DEVICE_ATTR(port_loc_code, S_IRUGO, ibmvfc_show_host_loc_code, NULL);
 static DEVICE_ATTR(drc_name, S_IRUGO, ibmvfc_show_host_drc_name, NULL);
 static DEVICE_ATTR(npiv_version, S_IRUGO, ibmvfc_show_host_npiv_version, NULL);
+static DEVICE_ATTR(capabilities, S_IRUGO, ibmvfc_show_host_capabilities, NULL);
 static DEVICE_ATTR(log_level, S_IRUGO | S_IWUSR,
                    ibmvfc_show_log_level, ibmvfc_store_log_level);
 
@@ -2609,6 +2636,7 @@ static struct device_attribute *ibmvfc_attrs[] = {
         &dev_attr_port_loc_code,
         &dev_attr_drc_name,
         &dev_attr_npiv_version,
+        &dev_attr_capabilities,
         &dev_attr_log_level,
         NULL
 };
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index 6adaad80565d..cf26380820fb 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -207,7 +207,8 @@ struct ibmvfc_npiv_login_resp {
 #define IBMVFC_NATIVE_FC                0x01
 #define IBMVFC_CAN_FLUSH_ON_HALT        0x08
         u32 reserved;
-        u64 capabilites;
+        u64 capabilities;
+#define IBMVFC_CAN_FLUSH_ON_HALT        0x08
         u32 max_cmds;
         u32 scsi_id_sz;
         u64 max_dma_len;
@@ -547,9 +548,17 @@ struct ibmvfc_crq_queue {
         dma_addr_t msg_token;
 };
 
+enum ibmvfc_ae_link_state {
+        IBMVFC_AE_LS_LINK_UP            = 0x01,
+        IBMVFC_AE_LS_LINK_BOUNCED       = 0x02,
+        IBMVFC_AE_LS_LINK_DOWN          = 0x04,
+        IBMVFC_AE_LS_LINK_DEAD          = 0x08,
+};
+
 struct ibmvfc_async_crq {
         volatile u8 valid;
-        u8 pad[3];
+        u8 link_state;
+        u8 pad[2];
         u32 pad2;
         volatile u64 event;
         volatile u64 scsi_id;