Newer
Older
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
* instructions, after we've decided that we need to run through
* the loop again.
*
* this should prevent any race conditions.
*
* ++roman: Just disabling the NCR interrupt isn't sufficient here,
* because also a timer int can trigger an abort or reset, which can
* alter queues and touch the Falcon lock.
*/
/* Tell int handlers main() is now already executing. Note that
no races are possible here. If an int comes in before
'main_running' is set here, and queues/executes main via the
task queue, it doesn't do any harm, just this instance of main
won't find any work left to do. */
if (main_running)
return;
main_running = 1;
local_save_flags(flags);
do {
local_irq_disable(); /* Freeze request queues */
done = 1;
if (!hostdata->connected) {
dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
/*
* 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 && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
;
/*printk("%p ", tmp);*/
if ((tmp == prev) && tmp)
printk(" LOOP\n");
/* else printk("\n"); */
for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
printk("MAIN tmp=%p target=%d busy=%d lun=%llu\n",
tmp, tmp->device->id, hostdata->busy[tmp->device->id],
/* When we find one, remove it from the issue queue. */
/* ++guenther: possible race with Falcon locking */
if (
!is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
!(hostdata->busy[tmp->device->id] & (1 << lun))
) {
/* ++guenther: just to be sure, this must be atomic */
local_irq_disable();
if (prev) {
REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
} else {
REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
hostdata->issue_queue = NEXT(tmp);
}
/* reenable interrupts after finding one */
local_irq_restore(flags);
/*
* Attempt to establish an I_T_L nexus here.
* On success, instance->hostdata->connected is set.
* On failure, we must add the command back to the
* issue queue so we can keep trying.
*/
dprintk(NDEBUG_MAIN, "scsi%d: main(): command for target %d "
"lun %d removed from issue_queue\n",
/*
* REQUEST SENSE commands are issued without tagged
* queueing, even on SCSI-II devices because the
* contingent allegiance condition exists for the
* entire unit.
*/
/* ++roman: ...and the standard also requires that
* REQUEST SENSE command are untagged.
*/
cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
if (!NCR5380_select(instance, tmp)) {
/* release if target did not response! */
maybe_release_dma_irq(instance);
local_irq_restore(flags);
break;
} else {
local_irq_disable();
LIST(tmp, hostdata->issue_queue);
SET_NEXT(tmp, hostdata->issue_queue);
dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
"returned to issue_queue\n", HOSTNO);
if (hostdata->connected)
break;
}
} /* if target/lun/target queue is not busy */
} /* for issue_queue */
} /* if (!hostdata->connected) */
if (hostdata->connected
dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
HOSTNO);
NCR5380_information_transfer(instance);
dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
done = 0;
}
} while (!done);
/* Better allow ints _after_ 'main_running' has been cleared, else
an interrupt could believe we'll pick up the work it left for
us, but we won't see it anymore here... */
main_running = 0;
local_irq_restore(flags);
}
#ifdef REAL_DMA
/*
* Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
*
* Purpose : Called by interrupt handler when DMA finishes or a phase
* mismatch occurs (which would finish the DMA transfer).
*
* Inputs : instance - this instance of the NCR5380.
*
*/
static void NCR5380_dma_complete(struct Scsi_Host *instance)
SETUP_HOSTDATA(instance);
int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
unsigned char **data, p;
volatile int *count;
if (!hostdata->connected) {
printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
"no connected cmd\n", HOSTNO);
return;
if (hostdata->read_overruns) {
p = hostdata->connected->SCp.phase;
if (p & SR_IO) {
udelay(10);
if ((NCR5380_read(BUS_AND_STATUS_REG) &
(BASR_PHASE_MATCH|BASR_ACK)) ==
(BASR_PHASE_MATCH|BASR_ACK)) {
saved_data = NCR5380_read(INPUT_DATA_REG);
overrun = 1;
dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
dprintk(NDEBUG_DMA, "scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
hostdata->dma_len = 0;
data = (unsigned char **)&hostdata->connected->SCp.ptr;
count = &hostdata->connected->SCp.this_residual;
*data += transfered;
*count -= transfered;
if (hostdata->read_overruns) {
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
cnt = toPIO = hostdata->read_overruns;
dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
*(*data)++ = saved_data;
(*count)--;
cnt--;
toPIO--;
}
dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
NCR5380_transfer_pio(instance, &p, &cnt, data);
*count -= toPIO - cnt;
}
}
}
#endif /* REAL_DMA */
/*
* Function : void NCR5380_intr (int irq)
* Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
* from the disconnected queue, and restarting NCR5380_main()
* as required.
*
* Inputs : int irq, irq that caused this interrupt.
*
*/
static irqreturn_t NCR5380_intr(int irq, void *dev_id)
struct Scsi_Host *instance = first_instance;
int done = 1, handled = 0;
unsigned char basr;
dprintk(NDEBUG_INTR, "scsi%d: NCR5380 irq triggered\n", HOSTNO);
/* Look for pending interrupts */
basr = NCR5380_read(BUS_AND_STATUS_REG);
dprintk(NDEBUG_INTR, "scsi%d: BASR=%02x\n", HOSTNO, basr);
/* dispatch to appropriate routine if found and done=0 */
if (basr & BASR_IRQ) {
NCR5380_dprint(NDEBUG_INTR, instance);
if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
done = 0;
dprintk(NDEBUG_INTR, "scsi%d: SEL interrupt\n", HOSTNO);
NCR5380_reselect(instance);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else if (basr & BASR_PARITY_ERROR) {
dprintk(NDEBUG_INTR, "scsi%d: PARITY interrupt\n", HOSTNO);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
dprintk(NDEBUG_INTR, "scsi%d: RESET interrupt\n", HOSTNO);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else {
/*
* The rest of the interrupt conditions can occur only during a
* DMA transfer
*/
/*
* We should only get PHASE MISMATCH and EOP interrupts if we have
* DMA enabled, so do a sanity check based on the current setting
* of the MODE register.
*/
if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
((basr & BASR_END_DMA_TRANSFER) ||
!(basr & BASR_PHASE_MATCH))) {
dprintk(NDEBUG_INTR, "scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
NCR5380_dma_complete( instance );
done = 0;
} else
/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
if (basr & BASR_PHASE_MATCH)
printk(KERN_NOTICE "scsi%d: unknown interrupt, "
"BASR 0x%x, MR 0x%x, SR 0x%x\n",
HOSTNO, basr, NCR5380_read(MODE_REG),
NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
} /* if !(SELECTION || PARITY) */
handled = 1;
} /* BASR & IRQ */ else {
printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
"BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
if (!done) {
dprintk(NDEBUG_INTR, "scsi%d: in int routine, calling main\n", HOSTNO);
/* Put a call to NCR5380_main() on the queue... */
queue_main();
}
return IRQ_RETVAL(handled);
* Function : int NCR5380_select(struct Scsi_Host *instance,
* struct scsi_cmnd *cmd)
*
* Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
* including ARBITRATION, SELECTION, and initial message out for
* IDENTIFY and queue messages.
* Inputs : instance - instantiation of the 5380 driver on which this
* target lives, cmd - SCSI command to execute.
* Returns : -1 if selection could not execute for some reason,
* 0 if selection succeeded or failed because the target
* did not respond.
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit
* with registers as they should have been on entry - ie
* SELECT_ENABLE will be set appropriately, the NCR5380
* will cease to drive any SCSI bus signals.
*
* If successful : I_T_L or I_T_L_Q nexus will be established,
* instance->connected will be set to cmd.
* SELECT interrupt will be disabled.
* If failed (no target) : cmd->scsi_done() will be called, and the
* cmd->result host byte set to DID_BAD_TARGET.
*/
static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
SETUP_HOSTDATA(instance);
unsigned char tmp[3], phase;
unsigned char *data;
int len;
unsigned long timeout;
unsigned long flags;
hostdata->restart_select = 0;
NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
instance->this_id);
/*
* Set the phase bits to 0, otherwise the NCR5380 won't drive the
* data bus during SELECTION.
*/
local_irq_save(flags);
if (hostdata->connected) {
local_irq_restore(flags);
return -1;
}
NCR5380_write(TARGET_COMMAND_REG, 0);
/*
* Start arbitration.
*/
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(MODE_REG, MR_ARBITRATE);
/* Wait for arbitration logic to complete */
{
unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
time_before(jiffies, timeout) && !hostdata->connected)
;
if (time_after_eq(jiffies, timeout)) {
printk("scsi : arbitration timeout at %d\n", __LINE__);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
}
while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
!hostdata->connected)
;
dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
if (hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
return -1;
}
/*
* The arbitration delay is 2.2us, but this is a minimum and there is
* no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
* the integral nature of udelay().
*
*/
udelay(3);
/* Check for lost arbitration */
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
(NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
/* after/during arbitration, BSY should be asserted.
IBM DPES-31080 Version S31Q works now */
/* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
HOSTNO);
return -1;
}
/*
* Again, bus clear + bus settle time is 1.2us, however, this is
* a minimum so we'll udelay ceil(1.2)
*/
/* ++roman: But some targets (see above :-) seem to need a bit more... */
udelay(15);
if (hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return -1;
}
dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
/*
* Now that we have won arbitration, start Selection process, asserting
* the host and target ID's on the SCSI bus.
*/
NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
/*
* Raise ATN while SEL is true before BSY goes false from arbitration,
* since this is the only way to guarantee that we'll get a MESSAGE OUT
* phase immediately after selection.
*/
NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
/*
* Reselect interrupts must be turned off prior to the dropping of BSY,
* otherwise we will trigger an interrupt.
*/
if (hostdata->connected) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return -1;
}
NCR5380_write(SELECT_ENABLE_REG, 0);
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
/*
* The initiator shall then wait at least two deskew delays and release
* the BSY signal.
*/
udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
/* Reset BSY */
NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
ICR_ASSERT_ATN | ICR_ASSERT_SEL));
/*
* Something weird happens when we cease to drive BSY - looks
* like the board/chip is letting us do another read before the
* appropriate propagation delay has expired, and we're confusing
* a BSY signal from ourselves as the target's response to SELECTION.
*
* A small delay (the 'C++' frontend breaks the pipeline with an
* unnecessary jump, making it work on my 386-33/Trantor T128, the
* tighter 'C' code breaks and requires this) solves the problem -
* the 1 us delay is arbitrary, and only used because this delay will
* be the same on other platforms and since it works here, it should
* work there.
*
* wingel suggests that this could be due to failing to wait
* one deskew delay.
*/
dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
/*
* The SCSI specification calls for a 250 ms timeout for the actual
* selection.
*/
/*
* XXX very interesting - we're seeing a bounce where the BSY we
* asserted is being reflected / still asserted (propagation delay?)
* and it's detecting as true. Sigh.
*/
/* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
* IO while SEL is true. But again, there are some disks out the in the
* world that do that nevertheless. (Somebody claimed that this announces
* reselection capability of the target.) So we better skip that test and
* only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
*/
while (time_before(jiffies, timeout) &&
!(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
;
if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_reselect(instance);
printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
HOSTNO);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
;
/*
* No less than two deskew delays after the initiator detects the
* BSY signal is true, it shall release the SEL signal and may
* change the DATA BUS. -wingel
*/
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
if (hostdata->targets_present & (1 << cmd->device->id)) {
printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
if (hostdata->restart_select)
printk(KERN_NOTICE "\trestart select\n");
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
cmd->result = DID_BAD_TARGET << 16;
cmd->scsi_done(cmd);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return 0;
}
hostdata->targets_present |= (1 << cmd->device->id);
/*
* Since we followed the SCSI spec, and raised ATN while SEL
* was true but before BSY was false during selection, the information
* transfer phase should be a MESSAGE OUT phase so that we can send the
* IDENTIFY message.
*
* If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
* message (2 bytes) with a tag ID that we increment with every command
* until it wraps back to 0.
*
* XXX - it turns out that there are some broken SCSI-II devices,
* which claim to support tagged queuing but fail when more than
* some number of commands are issued at once.
*/
/* Wait for start of REQ/ACK handshake */
while (!(NCR5380_read(STATUS_REG) & SR_REQ))
;
dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
HOSTNO, cmd->device->id);
tmp[0] = IDENTIFY(1, cmd->device->lun);
if (cmd->tag != TAG_NONE) {
tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
tmp[2] = cmd->tag;
len = 3;
} else
len = 1;
/* Send message(s) */
data = tmp;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
/* XXX need to handle errors here */
hostdata->connected = cmd;
hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif
/*
* Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using polled I/O
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes are transferred or exit
* Also, *phase, *count, *data are modified in place.
*
* XXX Note : handling for bus free may be useful.
*/
/*
* Note : this code is not as quick as it could be, however it
* IS 100% reliable, and for the actual data transfer where speed
* counts, we will always do a pseudo DMA or DMA transfer.
*/
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
register unsigned char p = *phase, tmp;
register int c = *count;
register unsigned char *d = *data;
/*
* The NCR5380 chip will only drive the SCSI bus when the
* phase specified in the appropriate bits of the TARGET COMMAND
* REGISTER match the STATUS REGISTER
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
do {
/*
* Wait for assertion of REQ, after which the phase bits will be
* valid
*/
while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
;
dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
/* Check for phase mismatch */
if ((tmp & PHASE_MASK) != p) {
dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
NCR5380_dprint_phase(NDEBUG_PIO, instance);
/* Do actual transfer from SCSI bus to / from memory */
if (!(p & SR_IO))
NCR5380_write(OUTPUT_DATA_REG, *d);
else
*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
/*
* The SCSI standard suggests that in MSGOUT phase, the initiator
* should drop ATN on the last byte of the message phase
* after REQ has been asserted for the handshake but before
* the initiator raises ACK.
*/
if (!(p & SR_IO)) {
if (!((p & SR_MSG) && c > 1)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ACK);
} else {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
}
} else {
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
}
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
/*
* We have several special cases to consider during REQ/ACK handshaking :
* 1. We were in MSGOUT phase, and we are on the last byte of the
* message. ATN must be dropped as ACK is dropped.
*
* 2. We are in a MSGIN phase, and we are on the last byte of the
* message. We must exit with ACK asserted, so that the calling
* code may raise ATN before dropping ACK to reject the message.
*
* 3. ACK and ATN are clear and the target may proceed as normal.
*/
if (!(p == PHASE_MSGIN && c == 1)) {
if (p == PHASE_MSGOUT && c > 1)
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
else
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
}
} while (--c);
dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
*count = c;
*data = d;
tmp = NCR5380_read(STATUS_REG);
/* The phase read from the bus is valid if either REQ is (already)
* asserted or if ACK hasn't been released yet. The latter is the case if
* we're in MSGIN and all wanted bytes have been received.
*/
if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
*phase = tmp & PHASE_MASK;
else
*phase = PHASE_UNKNOWN;
if (!c || (*phase == p))
return 0;
else
return -1;
}
/*
* Function : do_abort (Scsi_Host *host)
*
* Purpose : abort the currently established nexus. Should only be
* called from a routine which can drop into a
*
* Returns : 0 on success, -1 on failure.
*/
static int do_abort(struct Scsi_Host *host)
unsigned char tmp, *msgptr, phase;
int len;
/* Request message out phase */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
/*
* Wait for the target to indicate a valid phase by asserting
* REQ. Once this happens, we'll have either a MSGOUT phase
* and can immediately send the ABORT message, or we'll have some
* other phase and will have to source/sink data.
*
* We really don't care what value was on the bus or what value
* the target sees, so we just handshake.
*/
while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
;
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
ICR_ASSERT_ACK);
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
}
tmp = ABORT;
msgptr = &tmp;
len = 1;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(host, &phase, &len, &msgptr);
/*
* If we got here, and the command completed successfully,
* we're about to go into bus free state.
*/
return len ? -1 : 0;
/*
* Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using either real
* or pseudo DMA.
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes or transferred or exit
* Also, *phase, *count, *data are modified in place.
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
SETUP_HOSTDATA(instance);
register int c = *count;
register unsigned char p = *phase;
register unsigned char *d = *data;
unsigned char tmp;
unsigned long flags;
if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
*phase = tmp;
return -1;
}
if (hostdata->read_overruns && (p & SR_IO))
c -= hostdata->read_overruns;
dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
HOSTNO, (p & SR_IO) ? "reading" : "writing",
c, (p & SR_IO) ? "to" : "from", d);
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
/* On the Medusa, it is a must to initialize the DMA before
* starting the NCR. This is also the cleaner way for the TT.
*/
local_irq_save(flags);
hostdata->dma_len = (p & SR_IO) ?
NCR5380_dma_read_setup(instance, d, c) :
NCR5380_dma_write_setup(instance, d, c);
local_irq_restore(flags);
}
if (p & SR_IO)
NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
else {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_write(START_DMA_SEND_REG, 0);
}
if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
/* On the Falcon, the DMA setup must be done after the last */
/* NCR access, else the DMA setup gets trashed!
*/
local_irq_save(flags);
hostdata->dma_len = (p & SR_IO) ?
NCR5380_dma_read_setup(instance, d, c) :
NCR5380_dma_write_setup(instance, d, c);
local_irq_restore(flags);
}
return 0;
}
#endif /* defined(REAL_DMA) */
/*
* Function : NCR5380_information_transfer (struct Scsi_Host *instance)
*
* Purpose : run through the various SCSI phases and do as the target
* directs us to. Operates on the currently connected command,
* instance->connected.
*
* Inputs : instance, instance for which we are doing commands
*
* Side effects : SCSI things happen, the disconnected queue will be
* modified if a command disconnects, *instance->connected will
* change.
*
* XXX Note : we need to watch for bus free or a reset condition here
* to recover from an unexpected bus free condition.
static void NCR5380_information_transfer(struct Scsi_Host *instance)
SETUP_HOSTDATA(instance);
unsigned long flags;
unsigned char msgout = NOP;
int sink = 0;
int len;
unsigned char *data;
unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;
while (1) {
tmp = NCR5380_read(STATUS_REG);
/* We only have a valid SCSI phase when REQ is asserted */
if (tmp & SR_REQ) {
phase = (tmp & PHASE_MASK);
if (phase != old_phase) {
old_phase = phase;
NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
if (sink && (phase != PHASE_MSGOUT)) {
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
ICR_ASSERT_ACK);
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_ATN);
sink = 0;
continue;
}
switch (phase) {
case PHASE_DATAOUT:
printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
"aborted\n", HOSTNO);
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
case PHASE_DATAIN:
/*
* If there is no room left in the current buffer in the
* scatter-gather list, move onto the next one.
*/
if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
++cmd->SCp.buffer;
--cmd->SCp.buffers_residual;
cmd->SCp.this_residual = cmd->SCp.buffer->length;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
/* ++roman: Try to merge some scatter-buffers if
* they are at contiguous physical addresses.
*/
merge_contiguous_buffers(cmd);
dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
HOSTNO, cmd->SCp.this_residual,
cmd->SCp.buffers_residual);
}
/*
* The preferred transfer method is going to be
* PSEUDO-DMA for systems that are strictly PIO,
* since we can let the hardware do the handshaking.
*
* For this to work, we need to know the transfersize
* ahead of time, since the pseudo-DMA code will sit
* in an unconditional loop.
*/
/* ++roman: I suggest, this should be
* #if def(REAL_DMA)
* instead of leaving REAL_DMA out.
*/