[SCSI] advansys: Remove `waiting' queue

If the adapter is busy, return the request to the midlayer rather than
queueing it in the driver.  asc_execute_queue() and asc_dequeue() become
unused, and we don't need to print out stats on the waiting queue any more.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 9 insertions, 177 deletions

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index fe289b1d7ddb..526239a21332 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -2852,7 +2852,6 @@ typedef struct asc_board {
         } dvc_cfg;
         ushort asc_n_io_port;   /* Number I/O ports. */
         asc_queue_t active;     /* Active command queue */
-        asc_queue_t waiting;    /* Waiting command queue */
         asc_queue_t done;       /* Done command queue */
         ADV_SCSI_BIT_ID_TYPE init_tidmask;      /* Target init./valid mask */
         struct scsi_device *device[ADV_MAX_TID + 1];    /* Mid-Level Scsi Device */
@@ -2922,10 +2921,8 @@ static int asc_build_req(asc_board_t *, struct scsi_cmnd *);
 static int adv_build_req(asc_board_t *, struct scsi_cmnd *, ADV_SCSI_REQ_Q **);
 static int adv_get_sglist(asc_board_t *, adv_req_t *, struct scsi_cmnd *, int);
 static void asc_enqueue(asc_queue_t *, REQP, int);
-static REQP asc_dequeue(asc_queue_t *, int);
 static REQP asc_dequeue_list(asc_queue_t *, REQP *, int);
 static int asc_rmqueue(asc_queue_t *, REQP);
-static void asc_execute_queue(asc_queue_t *);
 #ifdef CONFIG_PROC_FS
 static int asc_proc_copy(off_t, off_t, char *, int, char *, int);
 static int asc_prt_board_devices(struct Scsi_Host *, char *, int);
@@ -3274,6 +3271,7 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
         asc_board_t *boardp;
         ulong flags;
         struct scsi_cmnd *done_scp;
+        int asc_res, result = 0;
 
         shost = scp->device->host;
         boardp = ASC_BOARDP(shost);
@@ -3302,37 +3300,13 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
                 return 0;
         }
 
-        /*
-         * Attempt to execute any waiting commands for the board.
-         */
-        if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
-                ASC_DBG(1,
-                        "advansys_queuecommand: before asc_execute_queue() waiting\n");
-                asc_execute_queue(&boardp->waiting);
-        }
-
-        /*
-         * Save the function pointer to Linux mid-level 'done' function
-         * and attempt to execute the command.
-         *
-         * If ASC_NOERROR is returned the request has been added to the
-         * board's 'active' queue and will be completed by the interrupt
-         * handler.
-         *
-         * If ASC_BUSY is returned add the request to the board's per
-         * target waiting list. This is the first time the request has
-         * been tried. Add it to the back of the waiting list. It will be
-         * retried later.
-         *
-         * If an error occurred, the request will have been placed on the
-         * board's 'done' queue and must be completed before returning.
-         */
         scp->scsi_done = done;
-        switch (asc_execute_scsi_cmnd(scp)) {
+        asc_res = asc_execute_scsi_cmnd(scp);
+        switch (asc_res) {
         case ASC_NOERROR:
                 break;
         case ASC_BUSY:
-                asc_enqueue(&boardp->waiting, scp, ASC_BACK);
+                result = SCSI_MLQUEUE_HOST_BUSY;
                 break;
         case ASC_ERROR:
         default:
@@ -3343,7 +3317,7 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
         }
         spin_unlock_irqrestore(&boardp->lock, flags);
 
-        return 0;
+        return result;
 }
 
 /*
@@ -3488,33 +3462,6 @@ static int advansys_reset(struct scsi_cmnd *scp)
                 }
         }
 
-        /*
-         * Dequeue all 'waiting' requests and set the request status
-         * to DID_RESET.
-         */
-        if (done_scp == NULL) {
-                done_scp = asc_dequeue_list(&boardp->waiting, &last_scp,
-                                            ASC_TID_ALL);
-                for (tscp = done_scp; tscp; tscp = REQPNEXT(tscp)) {
-                        tscp->result = HOST_BYTE(DID_RESET);
-                }
-        } else {
-                /* Append to 'done_scp' at the end with 'last_scp'. */
-                ASC_ASSERT(last_scp != NULL);
-                last_scp->host_scribble =
-                    (unsigned char *)asc_dequeue_list(&boardp->waiting,
-                                                      &new_last_scp,
-                                                      ASC_TID_ALL);
-                if (new_last_scp != NULL) {
-                        ASC_ASSERT(REQPNEXT(last_scp) != NULL);
-                        for (tscp = REQPNEXT(last_scp); tscp;
-                             tscp = REQPNEXT(tscp)) {
-                                tscp->result = HOST_BYTE(DID_RESET);
-                        }
-                        last_scp = new_last_scp;
-                }
-        }
-
         /* Save the time of the most recently completed reset. */
         boardp->last_reset = jiffies;
 
@@ -3650,7 +3597,7 @@ static irqreturn_t advansys_interrupt(int irq, void *dev_id)
         }
 
         /*
-         * Start waiting requests and create a list of completed requests.
+         * Create a list of completed requests.
          *
          * If a reset request is being performed for the board, the reset
          * handler will complete pending requests after it has completed.
@@ -3659,13 +3606,6 @@ static irqreturn_t advansys_interrupt(int irq, void *dev_id)
                 ASC_DBG2(1, "advansys_interrupt: done_scp 0x%p, "
                          "last_scp 0x%p\n", done_scp, last_scp);
 
-                /* Start any waiting commands for the board. */
-                if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
-                        ASC_DBG(1, "advansys_interrupt: before "
-                                "asc_execute_queue()\n");
-                        asc_execute_queue(&boardp->waiting);
-                }
-
                 /*
                  * Add to the list of requests that must be completed.
                  *
@@ -3986,8 +3926,8 @@ static void asc_scsi_done_list(struct scsi_cmnd *scp)
  * If this function returns ASC_NOERROR the request has been enqueued
  * on the board's 'done' queue and must be completed by the caller.
  *
- * If ASC_BUSY is returned the request will be enqueued by the
- * caller on the target's waiting queue and re-tried later.
+ * If ASC_BUSY is returned the request will be returned to the midlayer
+ * and re-tried later.
  */
 static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
 {
@@ -4043,10 +3983,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                                 "ASC_NOERROR\n");
                         break;
                 case ASC_BUSY:
-                        /*
-                         * Caller will enqueue request on the target's waiting
-                         * queue and retry later.
-                         */
                         ASC_STATS(scp->device->host, exe_busy);
                         break;
                 case ASC_ERROR:
@@ -4087,10 +4023,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                         ASC_DBG(1, "asc_execute_scsi_cmnd: adv_build_req "
                                 "ASC_BUSY\n");
                         /*
-                         * If busy is returned the request has not been
-                         * enqueued.  It will be enqueued by the caller on the
-                         * target's waiting queue and retried later.
-                         *
                          * The asc_stats fields 'adv_build_noreq' and
                          * 'adv_build_nosg' count wide board busy conditions.
                          * They are updated in adv_build_req and
@@ -4127,10 +4059,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                                 "ASC_NOERROR\n");
                         break;
                 case ASC_BUSY:
-                        /*
-                         * Caller will enqueue request on the target's waiting
-                         * queue and retry later.
-                         */
                         ASC_STATS(scp->device->host, exe_busy);
                         break;
                 case ASC_ERROR:
@@ -5005,39 +4933,6 @@ static void asc_enqueue(asc_queue_t *ascq, REQP reqp, int flag)
 }
 
 /*
- * Return first queued 'REQP' on the specified queue for
- * the specified target device. Clear the 'tidmask' bit for
- * the device if no more commands are left queued for it.
- *
- * 'REQPNEXT(reqp)' returns reqp's next pointer.
- */
-static REQP asc_dequeue(asc_queue_t *ascq, int tid)
-{
-        REQP reqp;
-
-        ASC_DBG2(3, "asc_dequeue: ascq 0x%lx, tid %d\n", (ulong)ascq, tid);
-        ASC_ASSERT(tid >= 0 && tid <= ADV_MAX_TID);
-        if ((reqp = ascq->q_first[tid]) != NULL) {
-                ASC_ASSERT(ascq->q_tidmask & ADV_TID_TO_TIDMASK(tid));
-                ascq->q_first[tid] = REQPNEXT(reqp);
-                /* If the queue is empty, clear its bit and the last pointer. */
-                if (ascq->q_first[tid] == NULL) {
-                        ascq->q_tidmask &= ~ADV_TID_TO_TIDMASK(tid);
-                        ASC_ASSERT(ascq->q_last[tid] == reqp);
-                        ascq->q_last[tid] = NULL;
-                }
-#ifdef ADVANSYS_STATS
-                /* Maintain request queue statistics. */
-                ascq->q_cur_cnt[tid]--;
-                ASC_ASSERT(ascq->q_cur_cnt[tid] >= 0);
-                REQTIMESTAT("asc_dequeue", ascq, reqp, tid);
-#endif /* ADVANSYS_STATS */
-        }
-        ASC_DBG1(3, "asc_dequeue: reqp 0x%lx\n", (ulong)reqp);
-        return reqp;
-}
-
-/*
  * Return a pointer to a singly linked list of all the requests queued
  * for 'tid' on the 'asc_queue_t' pointed to by 'ascq'.
  *
@@ -5202,45 +5097,6 @@ static int asc_rmqueue(asc_queue_t *ascq, REQP reqp)
         return ret;
 }
 
-/*
- * Execute as many queued requests as possible for the specified queue.
- *
- * Calls asc_execute_scsi_cmnd() to execute a REQP/struct scsi_cmnd.
- */
-static void asc_execute_queue(asc_queue_t *ascq)
-{
-        ADV_SCSI_BIT_ID_TYPE scan_tidmask;
-        REQP reqp;
-        int i;
-
-        ASC_DBG1(1, "asc_execute_queue: ascq 0x%lx\n", (ulong)ascq);
-        /*
-         * Execute queued commands for devices attached to
-         * the current board in round-robin fashion.
-         */
-        scan_tidmask = ascq->q_tidmask;
-        do {
-                for (i = 0; i <= ADV_MAX_TID; i++) {
-                        if (scan_tidmask & ADV_TID_TO_TIDMASK(i)) {
-                                if ((reqp = asc_dequeue(ascq, i)) == NULL) {
-                                        scan_tidmask &= ~ADV_TID_TO_TIDMASK(i);
-                                } else
-                                    if (asc_execute_scsi_cmnd
-                                        ((struct scsi_cmnd *)reqp)
-                                        == ASC_BUSY) {
-                                        scan_tidmask &= ~ADV_TID_TO_TIDMASK(i);
-                                        /*
-                                         * The request returned ASC_BUSY. Enqueue at the front of
-                                         * target's waiting list to maintain correct ordering.
-                                         */
-                                        asc_enqueue(ascq, reqp, ASC_FRONT);
-                                }
-                        }
-                }
-        } while (scan_tidmask);
-        return;
-}
-
 #ifdef CONFIG_PROC_FS
 /*
  * asc_prt_board_devices()
@@ -6723,7 +6579,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
         ushort chip_scsi_id;
         asc_board_t *boardp;
         asc_queue_t *active;
-        asc_queue_t *waiting;
 
         leftlen = cplen;
         totlen = len = 0;
@@ -6732,7 +6587,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
         s = &boardp->asc_stats;
 
         active = &ASC_BOARDP(shost)->active;
-        waiting = &ASC_BOARDP(shost)->waiting;
 
         if (ASC_NARROW_BOARD(boardp)) {
                 chip_scsi_id = boardp->dvc_cfg.asc_dvc_cfg.chip_scsi_id;
@@ -6746,8 +6600,7 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
         }
 
         do {
-                if (active->q_tot_cnt[tgt_id] > 0
-                    || waiting->q_tot_cnt[tgt_id] > 0) {
+                if (active->q_tot_cnt[tgt_id] > 0) {
                         len = asc_prt_line(cp, leftlen, " target %d\n", tgt_id);
                         ASC_PRT_NEXT();
 
@@ -6771,27 +6624,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
                                                                 q_tot_cnt
                                                                 [tgt_id]));
                         ASC_PRT_NEXT();
-
-                        len = asc_prt_line(cp, leftlen,
-                                           "   waiting: cnt [cur %d, max %d, tot %u], time [min %u, max %u, avg %lu.%01lu]\n",
-                                           waiting->q_cur_cnt[tgt_id],
-                                           waiting->q_max_cnt[tgt_id],
-                                           waiting->q_tot_cnt[tgt_id],
-                                           waiting->q_min_tim[tgt_id],
-                                           waiting->q_max_tim[tgt_id],
-                                           (waiting->q_tot_cnt[tgt_id] ==
-                                            0) ? 0 : (waiting->
-                                                      q_tot_tim[tgt_id] /
-                                                      waiting->
-                                                      q_tot_cnt[tgt_id]),
-                                           (waiting->q_tot_cnt[tgt_id] ==
-                                            0) ? 0 : ASC_TENTHS(waiting->
-                                                                q_tot_tim
-                                                                [tgt_id],
-                                                                waiting->
-                                                                q_tot_cnt
-                                                                [tgt_id]));
-                        ASC_PRT_NEXT();
                 }
         } while (0);