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ncr5380: Use standard list data structure

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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>
This commit is contained in:
Finn Thain
2016-01-03 16:05:58 +11:00
committed by Martin K. Petersen
parent 5299b3caf5
commit 32b26a1042
13 changed files with 106 additions and 421 deletions
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214
drivers/scsi/NCR5380.c
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@@ -622,8 +622,9 @@ static int NCR5380_init(struct Scsi_Host *instance, int flags)
#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 @@ static int NCR5380_queue_command(struct Scsi_Host *instance,
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 @@ static int NCR5380_queue_command(struct Scsi_Host *instance,
}
#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 @@ static int NCR5380_queue_command(struct Scsi_Host *instance,
* 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 @@ static void NCR5380_main(struct work_struct *work)
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 @@ static void NCR5380_main(struct work_struct *work)
* 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 @@ static void NCR5380_main(struct work_struct *work)
/* 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 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) {
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 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) {
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 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) {
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 @@ static void NCR5380_reselect(struct Scsi_Host *instance) {
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 @@ static void NCR5380_reselect(struct Scsi_Host *instance) {
* 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 @@ static int NCR5380_abort(struct scsi_cmnd *cmd)
{
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;
}