ncr5380: Use standard list data structure
The NCR5380 drivers have a home-spun linked list implementation for
scsi_cmnd structs that uses cmd->host_scribble as a 'next' pointer. Adopt
the standard list_head data structure and list operations instead. Remove
the eh_abort_handler rather than convert it. Doing the conversion would
only be churn because the existing EH handlers don't work and get replaced
in a subsequent patch.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 9e86363..6b861fd 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -622,8 +622,9 @@
#endif
spin_lock_init(&hostdata->lock);
hostdata->connected = NULL;
- hostdata->issue_queue = NULL;
- hostdata->disconnected_queue = NULL;
+ INIT_LIST_HEAD(&hostdata->unissued);
+ INIT_LIST_HEAD(&hostdata->disconnected);
+
hostdata->flags = flags;
INIT_WORK(&hostdata->main_task, NCR5380_main);
@@ -738,7 +739,7 @@
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
- struct scsi_cmnd *tmp;
+ struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
unsigned long flags;
#if (NDEBUG & NDEBUG_NO_WRITE)
@@ -752,12 +753,6 @@
}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
- /*
- * We use the host_scribble field as a pointer to the next command
- * in a queue
- */
-
- cmd->host_scribble = NULL;
cmd->result = 0;
spin_lock_irqsave(&hostdata->lock, flags);
@@ -769,13 +764,11 @@
* sense data is only guaranteed to be valid while the condition exists.
*/
- if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
- cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
- hostdata->issue_queue = cmd;
- } else {
- for (tmp = (struct scsi_cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (struct scsi_cmnd *) tmp->host_scribble);
- tmp->host_scribble = (unsigned char *) cmd;
- }
+ if (cmd->cmnd[0] == REQUEST_SENSE)
+ list_add(&ncmd->list, &hostdata->unissued);
+ else
+ list_add_tail(&ncmd->list, &hostdata->unissued);
+
spin_unlock_irqrestore(&hostdata->lock, flags);
dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
@@ -803,7 +796,7 @@
struct NCR5380_hostdata *hostdata =
container_of(work, struct NCR5380_hostdata, main_task);
struct Scsi_Host *instance = hostdata->host;
- struct scsi_cmnd *tmp, *prev;
+ struct NCR5380_cmd *ncmd, *n;
int done;
spin_lock_irq(&hostdata->lock);
@@ -816,23 +809,20 @@
* Search through the issue_queue for a command destined
* for a target that's not busy.
*/
- for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (struct scsi_cmnd *) tmp->host_scribble)
- {
+ list_for_each_entry_safe(ncmd, n, &hostdata->unissued,
+ list) {
+ struct scsi_cmnd *tmp = NCR5380_to_scmd(ncmd);
+
dsprintk(NDEBUG_QUEUES, instance, "main: tmp=%p target=%d busy=%d lun=%llu\n",
tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
tmp->device->lun);
/* When we find one, remove it from the issue queue. */
if (!(hostdata->busy[tmp->device->id] &
(1 << (u8)(tmp->device->lun & 0xff)))) {
- if (prev) {
- prev->host_scribble = tmp->host_scribble;
- } else {
- hostdata->issue_queue = (struct scsi_cmnd *) tmp->host_scribble;
- }
- tmp->host_scribble = NULL;
+ list_del(&ncmd->list);
dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES,
- instance, "main: removed %p from issue queue %p\n",
- tmp, prev);
+ instance, "main: removed %p from issue queue\n",
+ tmp);
/*
* Attempt to establish an I_T_L nexus here.
@@ -851,8 +841,7 @@
/* OK or bad target */
} else {
/* Need to retry */
- tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
- hostdata->issue_queue = tmp;
+ list_add(&ncmd->list, &hostdata->unissued);
dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES,
instance, "main: select() failed, %p returned to issue queue\n",
tmp);
@@ -1744,6 +1733,8 @@
struct scsi_cmnd *cmd;
while ((cmd = hostdata->connected)) {
+ struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
+
tmp = NCR5380_read(STATUS_REG);
/* We only have a valid SCSI phase when REQ is asserted */
if (tmp & SR_REQ) {
@@ -1875,9 +1866,7 @@
if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
- cmd->host_scribble = (unsigned char *)
- hostdata->issue_queue;
- hostdata->issue_queue = (struct scsi_cmnd *) cmd;
+ list_add(&ncmd->list, &hostdata->unissued);
dsprintk(NDEBUG_AUTOSENSE | NDEBUG_QUEUES,
instance, "REQUEST SENSE cmd %p added to head of issue queue\n",
cmd);
@@ -1911,10 +1900,8 @@
case DISCONNECT:{
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
- cmd->host_scribble = (unsigned char *)
- hostdata->disconnected_queue;
hostdata->connected = NULL;
- hostdata->disconnected_queue = cmd;
+ list_add(&ncmd->list, &hostdata->disconnected);
dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
cmd, scmd_id(cmd), cmd->device->lun);
@@ -2087,7 +2074,8 @@
int len;
unsigned char msg[3];
unsigned char *data;
- struct scsi_cmnd *tmp = NULL, *prev;
+ struct NCR5380_cmd *ncmd;
+ struct scsi_cmnd *tmp;
/*
* Disable arbitration, etc. since the host adapter obviously
@@ -2156,16 +2144,14 @@
* just reestablished, and remove it from the disconnected queue.
*/
- for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
- tmp; prev = tmp, tmp = (struct scsi_cmnd *) tmp->host_scribble) {
- if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)) {
- if (prev) {
- prev->host_scribble = tmp->host_scribble;
- } else {
- hostdata->disconnected_queue =
- (struct scsi_cmnd *) tmp->host_scribble;
- }
- tmp->host_scribble = NULL;
+ tmp = NULL;
+ list_for_each_entry(ncmd, &hostdata->disconnected, list) {
+ struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
+
+ if (target_mask == (1 << scmd_id(cmd)) &&
+ lun == (u8)cmd->device->lun) {
+ list_del(&ncmd->list);
+ tmp = cmd;
break;
}
}
@@ -2261,146 +2247,18 @@
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
- struct scsi_cmnd *tmp, **prev;
unsigned long flags;
- scmd_printk(KERN_WARNING, cmd, "aborting command\n");
-
spin_lock_irqsave(&hostdata->lock, flags);
+#if (NDEBUG & NDEBUG_ANY)
+ scmd_printk(KERN_INFO, cmd, "aborting command\n");
+#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
- dprintk(NDEBUG_ABORT, "scsi%d : abort called\n", instance->host_no);
- dprintk(NDEBUG_ABORT, " basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG));
-
-#if 0
-/*
- * Case 1 : If the command is the currently executing command,
- * we'll set the aborted flag and return control so that
- * information transfer routine can exit cleanly.
- */
-
- if (hostdata->connected == cmd) {
- dprintk(NDEBUG_ABORT, "scsi%d : aborting connected command\n", instance->host_no);
-/*
- * We should perform BSY checking, and make sure we haven't slipped
- * into BUS FREE.
- */
-
- NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
-/*
- * Since we can't change phases until we've completed the current
- * handshake, we have to source or sink a byte of data if the current
- * phase is not MSGOUT.
- */
-
-/*
- * Return control to the executing NCR drive so we can clear the
- * aborted flag and get back into our main loop.
- */
-
- return SUCCESS;
- }
-#endif
-
-/*
- * Case 2 : If the command hasn't been issued yet, we simply remove it
- * from the issue queue.
- */
-
- dprintk(NDEBUG_ABORT, "scsi%d : abort going into loop.\n", instance->host_no);
- for (prev = (struct scsi_cmnd **) &(hostdata->issue_queue), tmp = (struct scsi_cmnd *) hostdata->issue_queue; tmp; prev = (struct scsi_cmnd **) &(tmp->host_scribble), tmp = (struct scsi_cmnd *) tmp->host_scribble)
- if (cmd == tmp) {
- (*prev) = (struct scsi_cmnd *) tmp->host_scribble;
- tmp->host_scribble = NULL;
- spin_unlock_irqrestore(&hostdata->lock, flags);
- tmp->result = DID_ABORT << 16;
- dprintk(NDEBUG_ABORT, "scsi%d : abort removed command from issue queue.\n", instance->host_no);
- tmp->scsi_done(tmp);
- return SUCCESS;
- }
-#if (NDEBUG & NDEBUG_ABORT)
- /* KLL */
- else if (prev == tmp)
- printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
-#endif
-
-/*
- * Case 3 : If any commands are connected, we're going to fail the abort
- * and let the high level SCSI driver retry at a later time or
- * issue a reset.
- *
- * Timeouts, and therefore aborted commands, will be highly unlikely
- * and handling them cleanly in this situation would make the common
- * case of noresets less efficient, and would pollute our code. So,
- * we fail.
- */
-
- if (hostdata->connected) {
- spin_unlock_irqrestore(&hostdata->lock, flags);
- dprintk(NDEBUG_ABORT, "scsi%d : abort failed, command connected.\n", instance->host_no);
- return FAILED;
- }
-/*
- * Case 4: If the command is currently disconnected from the bus, and
- * there are no connected commands, we reconnect the I_T_L or
- * I_T_L_Q nexus associated with it, go into message out, and send
- * an abort message.
- *
- * This case is especially ugly. In order to reestablish the nexus, we
- * need to call NCR5380_select(). The easiest way to implement this
- * function was to abort if the bus was busy, and let the interrupt
- * handler triggered on the SEL for reselect take care of lost arbitrations
- * where necessary, meaning interrupts need to be enabled.
- *
- * When interrupts are enabled, the queues may change - so we
- * can't remove it from the disconnected queue before selecting it
- * because that could cause a failure in hashing the nexus if that
- * device reselected.
- *
- * Since the queues may change, we can't use the pointers from when we
- * first locate it.
- *
- * So, we must first locate the command, and if NCR5380_select()
- * succeeds, then issue the abort, relocate the command and remove
- * it from the disconnected queue.
- */
-
- for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp; tmp = (struct scsi_cmnd *) tmp->host_scribble)
- if (cmd == tmp) {
- dprintk(NDEBUG_ABORT, "scsi%d : aborting disconnected command.\n", instance->host_no);
-
- if (NCR5380_select(instance, cmd)) {
- spin_unlock_irq(&hostdata->lock);
- return FAILED;
- }
- dprintk(NDEBUG_ABORT, "scsi%d : nexus reestablished.\n", instance->host_no);
-
- do_abort(instance);
-
- for (prev = (struct scsi_cmnd **) &(hostdata->disconnected_queue), tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp; prev = (struct scsi_cmnd **) &(tmp->host_scribble), tmp = (struct scsi_cmnd *) tmp->host_scribble)
- if (cmd == tmp) {
- *prev = (struct scsi_cmnd *) tmp->host_scribble;
- tmp->host_scribble = NULL;
- spin_unlock_irqrestore(&hostdata->lock, flags);
- tmp->result = DID_ABORT << 16;
- tmp->scsi_done(tmp);
- return SUCCESS;
- }
- }
-/*
- * Case 5 : If we reached this point, the command was not found in any of
- * the queues.
- *
- * We probably reached this point because of an unlikely race condition
- * between the command completing successfully and the abortion code,
- * so we won't panic, but we will notify the user in case something really
- * broke.
- */
spin_unlock_irqrestore(&hostdata->lock, flags);
- printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
- " before abortion\n", instance->host_no);
+
return FAILED;
}