[SCSI] zfcp: improve management of request IDs

Improve request handling. Use hash table to manage request IDs.

Signed-off-by: Volker Sameske <sameske@de.ibm.com>
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 65 insertions, 57 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 31db2b06fab..ff2eacf5ec8 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -49,7 +49,6 @@ static int zfcp_fsf_fsfstatus_qual_eval(struct zfcp_fsf_req *);
 static void zfcp_fsf_link_down_info_eval(struct zfcp_adapter *,
         struct fsf_link_down_info *);
 static int zfcp_fsf_req_dispatch(struct zfcp_fsf_req *);
-static void zfcp_fsf_req_dismiss(struct zfcp_fsf_req *);
 
 /* association between FSF command and FSF QTCB type */
 static u32 fsf_qtcb_type[] = {
@@ -146,47 +145,48 @@ zfcp_fsf_req_free(struct zfcp_fsf_req *fsf_req)
                 kfree(fsf_req);
 }
 
-/*
- * function:    
- *
- * purpose:     
- *
- * returns:
- *
- * note: qdio queues shall be down (no ongoing inbound processing)
+/**
+ * zfcp_fsf_req_dismiss - dismiss a single fsf request
  */
-int
-zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
+static void zfcp_fsf_req_dismiss(struct zfcp_adapter *adapter,
+                                 struct zfcp_fsf_req *fsf_req,
+                                 unsigned int counter)
 {
-        struct zfcp_fsf_req *fsf_req, *tmp;
-        unsigned long flags;
-        LIST_HEAD(remove_queue);
+        u64 dbg_tmp[2];
 
-        spin_lock_irqsave(&adapter->fsf_req_list_lock, flags);
-        list_splice_init(&adapter->fsf_req_list_head, &remove_queue);
-        atomic_set(&adapter->fsf_reqs_active, 0);
-        spin_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);
-
-        list_for_each_entry_safe(fsf_req, tmp, &remove_queue, list) {
-                list_del(&fsf_req->list);
-                zfcp_fsf_req_dismiss(fsf_req);
-        }
-
-        return 0;
+        dbg_tmp[0] = (u64) atomic_read(&adapter->reqs_active);
+        dbg_tmp[1] = (u64) counter;
+        debug_event(adapter->erp_dbf, 4, (void *) dbg_tmp, 16);
+        list_del(&fsf_req->list);
+        fsf_req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
+        zfcp_fsf_req_complete(fsf_req);
 }
 
-/*
- * function:    
- *
- * purpose:     
- *
- * returns:
+/**
+ * zfcp_fsf_req_dismiss_all - dismiss all remaining fsf requests
  */
-static void
-zfcp_fsf_req_dismiss(struct zfcp_fsf_req *fsf_req)
+int zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
 {
-        fsf_req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
-        zfcp_fsf_req_complete(fsf_req);
+        struct zfcp_fsf_req *request, *tmp;
+        unsigned long flags;
+        unsigned int i, counter;
+
+        spin_lock_irqsave(&adapter->req_list_lock, flags);
+        atomic_set(&adapter->reqs_active, 0);
+        for (i=0; i<REQUEST_LIST_SIZE; i++) {
+                if (list_empty(&adapter->req_list[i]))
+                        continue;
+
+                counter = 0;
+                list_for_each_entry_safe(request, tmp,
+                                         &adapter->req_list[i], list) {
+                        zfcp_fsf_req_dismiss(adapter, request, counter);
+                        counter++;
+                }
+        }
+        spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+
+        return 0;
 }
 
 /*
@@ -4592,12 +4592,14 @@ static inline void
 zfcp_fsf_req_qtcb_init(struct zfcp_fsf_req *fsf_req)
 {
         if (likely(fsf_req->qtcb != NULL)) {
-                fsf_req->qtcb->prefix.req_seq_no = fsf_req->adapter->fsf_req_seq_no;
-                fsf_req->qtcb->prefix.req_id = (unsigned long)fsf_req;
+                fsf_req->qtcb->prefix.req_seq_no =
+                        fsf_req->adapter->fsf_req_seq_no;
+                fsf_req->qtcb->prefix.req_id = fsf_req->req_id;
                 fsf_req->qtcb->prefix.ulp_info = ZFCP_ULP_INFO_VERSION;
-                fsf_req->qtcb->prefix.qtcb_type = fsf_qtcb_type[fsf_req->fsf_command];
+                fsf_req->qtcb->prefix.qtcb_type =
+                        fsf_qtcb_type[fsf_req->fsf_command];
                 fsf_req->qtcb->prefix.qtcb_version = ZFCP_QTCB_VERSION;
-                fsf_req->qtcb->header.req_handle = (unsigned long)fsf_req;
+                fsf_req->qtcb->header.req_handle = fsf_req->req_id;
                 fsf_req->qtcb->header.fsf_command = fsf_req->fsf_command;
         }
 }
@@ -4654,6 +4656,7 @@ zfcp_fsf_req_create(struct zfcp_adapter *adapter, u32 fsf_cmd, int req_flags,
 {
         volatile struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *fsf_req = NULL;
+        unsigned long flags;
         int ret = 0;
         struct zfcp_qdio_queue *req_queue = &adapter->request_queue;
 
@@ -4668,6 +4671,12 @@ zfcp_fsf_req_create(struct zfcp_adapter *adapter, u32 fsf_cmd, int req_flags,
 
         fsf_req->adapter = adapter;
         fsf_req->fsf_command = fsf_cmd;
+        INIT_LIST_HEAD(&fsf_req->list);
+        
+        /* unique request id */
+        spin_lock_irqsave(&adapter->req_list_lock, flags);
+        fsf_req->req_id = adapter->req_no++;
+        spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 
         zfcp_fsf_req_qtcb_init(fsf_req);
 
@@ -4707,7 +4716,7 @@ zfcp_fsf_req_create(struct zfcp_adapter *adapter, u32 fsf_cmd, int req_flags,
         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 
         /* setup common SBALE fields */
-        sbale[0].addr = fsf_req;
+        sbale[0].addr = (void *) fsf_req->req_id;
         sbale[0].flags |= SBAL_FLAGS0_COMMAND;
         if (likely(fsf_req->qtcb != NULL)) {
                 sbale[1].addr = (void *) fsf_req->qtcb;
@@ -4747,7 +4756,7 @@ zfcp_fsf_req_send(struct zfcp_fsf_req *fsf_req, struct timer_list *timer)
         volatile struct qdio_buffer_element *sbale;
         int inc_seq_no;
         int new_distance_from_int;
-        unsigned long flags;
+        u64 dbg_tmp[2];
         int retval = 0;
 
         adapter = fsf_req->adapter;
@@ -4761,10 +4770,10 @@ zfcp_fsf_req_send(struct zfcp_fsf_req *fsf_req, struct timer_list *timer)
         ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_TRACE, (char *) sbale[1].addr,
                       sbale[1].length);
 
-        /* put allocated FSF request at list tail */
-        spin_lock_irqsave(&adapter->fsf_req_list_lock, flags);
-        list_add_tail(&fsf_req->list, &adapter->fsf_req_list_head);
-        spin_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);
+        /* put allocated FSF request into hash table */
+        spin_lock(&adapter->req_list_lock);
+        zfcp_reqlist_add(adapter, fsf_req);
+        spin_unlock(&adapter->req_list_lock);
 
         inc_seq_no = (fsf_req->qtcb != NULL);
 
@@ -4803,6 +4812,10 @@ zfcp_fsf_req_send(struct zfcp_fsf_req *fsf_req, struct timer_list *timer)
                          QDIO_FLAG_SYNC_OUTPUT,
                          0, fsf_req->sbal_first, fsf_req->sbal_number, NULL);
 
+        dbg_tmp[0] = (unsigned long) sbale[0].addr;
+        dbg_tmp[1] = (u64) retval;
+        debug_event(adapter->erp_dbf, 4, (void *) dbg_tmp, 16);
+
         if (unlikely(retval)) {
                 /* Queues are down..... */
                 retval = -EIO;
@@ -4812,22 +4825,17 @@ zfcp_fsf_req_send(struct zfcp_fsf_req *fsf_req, struct timer_list *timer)
                  */
                 if (timer)
                         del_timer(timer);
-                spin_lock_irqsave(&adapter->fsf_req_list_lock, flags);
-                list_del(&fsf_req->list);
-                spin_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);
-                /*
-                 * adjust the number of free SBALs in request queue as well as
-                 * position of first one
-                 */
+                spin_lock(&adapter->req_list_lock);
+                zfcp_reqlist_remove(adapter, fsf_req->req_id);
+                spin_unlock(&adapter->req_list_lock);
+                /* undo changes in request queue made for this request */
                 zfcp_qdio_zero_sbals(req_queue->buffer,
                                      fsf_req->sbal_first, fsf_req->sbal_number);
                 atomic_add(fsf_req->sbal_number, &req_queue->free_count);
-                req_queue->free_index -= fsf_req->sbal_number;   /* increase */
+                req_queue->free_index -= fsf_req->sbal_number;
                 req_queue->free_index += QDIO_MAX_BUFFERS_PER_Q;
                 req_queue->free_index %= QDIO_MAX_BUFFERS_PER_Q; /* wrap */
-                ZFCP_LOG_DEBUG
-                        ("error: do_QDIO failed. Buffers could not be enqueued "
-                         "to request queue.\n");
+                zfcp_erp_adapter_reopen(adapter, 0);
         } else {
                 req_queue->distance_from_int = new_distance_from_int;
                 /*
@@ -4843,7 +4851,7 @@ zfcp_fsf_req_send(struct zfcp_fsf_req *fsf_req, struct timer_list *timer)
                         adapter->fsf_req_seq_no++;
 
                 /* count FSF requests pending */
-                atomic_inc(&adapter->fsf_reqs_active);
+                atomic_inc(&adapter->reqs_active);
         }
         return retval;
 }