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[SCSI] advansys: Remove `waiting' queue
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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>
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Matthew Wilcox authored and James Bottomley committed Oct 12, 2007
1 parent c2dce2f commit b662292
Showing 1 changed file with 9 additions and 177 deletions.
186 changes: 9 additions & 177 deletions drivers/scsi/advansys.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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:
Expand All @@ -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;
}

/*
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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.
Expand All @@ -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.
*
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -5004,39 +4932,6 @@ static void asc_enqueue(asc_queue_t *ascq, REQP reqp, int flag)
return;
}

/*
* 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'.
Expand Down Expand Up @@ -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()
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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();

Expand All @@ -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);

Expand Down

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