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linux/drivers/scsi/NCR5380.c

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// SPDX-License-Identifier: GPL-2.0
/*
* NCR 5380 generic driver routines. These should make it *trivial*
* to implement 5380 SCSI drivers under Linux with a non-trantor
* architecture.
*
* Note that these routines also work with NR53c400 family chips.
*
* Copyright 1993, Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* drew@colorado.edu
* +1 (303) 666-5836
*
* For more information, please consult
*
* NCR 5380 Family
* SCSI Protocol Controller
* Databook
*
* NCR Microelectronics
* 1635 Aeroplaza Drive
* Colorado Springs, CO 80916
* 1+ (719) 578-3400
* 1+ (800) 334-5454
*/
/*
* With contributions from Ray Van Tassle, Ingmar Baumgart,
* Ronald van Cuijlenborg, Alan Cox and others.
*/
/* Ported to Atari by Roman Hodek and others. */
/* Adapted for the Sun 3 by Sam Creasey. */
/*
* Design
*
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* memory mapped) and drops this file in their 'C' wrapper.
*
* As far as command queueing, two queues are maintained for
* each 5380 in the system - commands that haven't been issued yet,
* and commands that are currently executing. This means that an
* unlimited number of commands may be queued, letting
* more commands propagate from the higher driver levels giving higher
* throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
*
* Issues specific to the NCR5380 :
*
* When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
* piece of hardware that requires you to sit in a loop polling for
* the REQ signal as long as you are connected. Some devices are
* brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
* while doing long seek operations. [...] These
* broken devices are the exception rather than the rule and I'd rather
* spend my time optimizing for the normal case.
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
* which is started from a workqueue for each NCR5380 host in the
* system. It attempts to establish I_T_L or I_T_L_Q nexuses by
* removing the commands from the issue queue and calling
* NCR5380_select() if a nexus is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
* if the target goes into MSG IN and sends a DISCONNECT message,
* the command structure is placed into the per instance disconnected
* queue, and NCR5380_main tries to find more work. If the target is
* idle for too long, the system will try to sleep.
*
* If a command has disconnected, eventually an interrupt will trigger,
* calling NCR5380_intr() which will in turn call NCR5380_reselect
* to reestablish a nexus. This will run main if necessary.
*
* On command termination, the done function will be called as
* appropriate.
*
* SCSI pointers are maintained in the SCp field of SCSI command
* structures, being initialized after the command is connected
* in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
* Note that in violation of the standard, an implicit SAVE POINTERS operation
* is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
*/
/*
* Using this file :
* This file a skeleton Linux SCSI driver for the NCR 5380 series
* of chips. To use it, you write an architecture specific functions
* and macros and include this file in your driver.
*
* These macros MUST be defined :
*
* NCR5380_read(register) - read from the specified register
*
* NCR5380_write(register, value) - write to the specific register
*
* NCR5380_implementation_fields - additional fields needed for this
* specific implementation of the NCR5380
*
* Either real DMA *or* pseudo DMA may be implemented
*
* NCR5380_dma_xfer_len - determine size of DMA/PDMA transfer
* NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
* NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
* NCR5380_dma_residual - residual byte count
*
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID.
*/
#ifndef NCR5380_io_delay
#define NCR5380_io_delay(x)
#endif
#ifndef NCR5380_acquire_dma_irq
#define NCR5380_acquire_dma_irq(x) (1)
#endif
#ifndef NCR5380_release_dma_irq
#define NCR5380_release_dma_irq(x)
#endif
static int do_abort(struct Scsi_Host *);
static void do_reset(struct Scsi_Host *);
/**
* initialize_SCp - init the scsi pointer field
* @cmd: command block to set up
*
* Set up the internal fields in the SCSI command.
*/
static inline void initialize_SCp(struct scsi_cmnd *cmd)
{
/*
* Initialize the Scsi Pointer field so that all of the commands in the
* various queues are valid.
*/
if (scsi_bufflen(cmd)) {
cmd->SCp.buffer = scsi_sglist(cmd);
cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
} else {
cmd->SCp.buffer = NULL;
cmd->SCp.buffers_residual = 0;
cmd->SCp.ptr = NULL;
cmd->SCp.this_residual = 0;
}
cmd->SCp.Status = 0;
cmd->SCp.Message = 0;
}
/**
* NCR5380_poll_politely2 - wait for two chip register values
* @hostdata: host private data
* @reg1: 5380 register to poll
* @bit1: Bitmask to check
* @val1: Expected value
* @reg2: Second 5380 register to poll
* @bit2: Second bitmask to check
* @val2: Second expected value
* @wait: Time-out in jiffies
*
* Polls the chip in a reasonably efficient manner waiting for an
* event to occur. After a short quick poll we begin to yield the CPU
* (if possible). In irq contexts the time-out is arbitrarily limited.
* Callers may hold locks as long as they are held in irq mode.
*
* Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
*/
static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
unsigned int reg1, u8 bit1, u8 val1,
unsigned int reg2, u8 bit2, u8 val2,
unsigned long wait)
{
unsigned long n = hostdata->poll_loops;
unsigned long deadline = jiffies + wait;
do {
if ((NCR5380_read(reg1) & bit1) == val1)
return 0;
if ((NCR5380_read(reg2) & bit2) == val2)
return 0;
cpu_relax();
} while (n--);
if (irqs_disabled() || in_interrupt())
return -ETIMEDOUT;
/* Repeatedly sleep for 1 ms until deadline */
while (time_is_after_jiffies(deadline)) {
schedule_timeout_uninterruptible(1);
if ((NCR5380_read(reg1) & bit1) == val1)
return 0;
if ((NCR5380_read(reg2) & bit2) == val2)
return 0;
}
return -ETIMEDOUT;
}
#if NDEBUG
static struct {
unsigned char mask;
const char *name;
} signals[] = {
{SR_DBP, "PARITY"},
{SR_RST, "RST"},
{SR_BSY, "BSY"},
{SR_REQ, "REQ"},
{SR_MSG, "MSG"},
{SR_CD, "CD"},
{SR_IO, "IO"},
{SR_SEL, "SEL"},
{0, NULL}
},
basrs[] = {
{BASR_END_DMA_TRANSFER, "END OF DMA"},
{BASR_DRQ, "DRQ"},
{BASR_PARITY_ERROR, "PARITY ERROR"},
{BASR_IRQ, "IRQ"},
{BASR_PHASE_MATCH, "PHASE MATCH"},
{BASR_BUSY_ERROR, "BUSY ERROR"},
{BASR_ATN, "ATN"},
{BASR_ACK, "ACK"},
{0, NULL}
},
icrs[] = {
{ICR_ASSERT_RST, "ASSERT RST"},
{ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
{ICR_ARBITRATION_LOST, "LOST ARB."},
{ICR_ASSERT_ACK, "ASSERT ACK"},
{ICR_ASSERT_BSY, "ASSERT BSY"},
{ICR_ASSERT_SEL, "ASSERT SEL"},
{ICR_ASSERT_ATN, "ASSERT ATN"},
{ICR_ASSERT_DATA, "ASSERT DATA"},
{0, NULL}
},
mrs[] = {
{MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
{MR_TARGET, "TARGET"},
{MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
{MR_ENABLE_PAR_INTR, "PARITY INTR"},
{MR_ENABLE_EOP_INTR, "EOP INTR"},
{MR_MONITOR_BSY, "MONITOR BSY"},
{MR_DMA_MODE, "DMA MODE"},
{MR_ARBITRATE, "ARBITRATE"},
{0, NULL}
};
/**
* NCR5380_print - print scsi bus signals
* @instance: adapter state to dump
*
* Print the SCSI bus signals for debugging purposes
*/
static void NCR5380_print(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char status, data, basr, mr, icr, i;
data = NCR5380_read(CURRENT_SCSI_DATA_REG);
status = NCR5380_read(STATUS_REG);
mr = NCR5380_read(MODE_REG);
icr = NCR5380_read(INITIATOR_COMMAND_REG);
basr = NCR5380_read(BUS_AND_STATUS_REG);
printk(KERN_DEBUG "SR = 0x%02x : ", status);
for (i = 0; signals[i].mask; ++i)
if (status & signals[i].mask)
printk(KERN_CONT "%s, ", signals[i].name);
printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
for (i = 0; basrs[i].mask; ++i)
if (basr & basrs[i].mask)
printk(KERN_CONT "%s, ", basrs[i].name);
printk(KERN_CONT "\nICR = 0x%02x : ", icr);
for (i = 0; icrs[i].mask; ++i)
if (icr & icrs[i].mask)
printk(KERN_CONT "%s, ", icrs[i].name);
printk(KERN_CONT "\nMR = 0x%02x : ", mr);
for (i = 0; mrs[i].mask; ++i)
if (mr & mrs[i].mask)
printk(KERN_CONT "%s, ", mrs[i].name);
printk(KERN_CONT "\n");
}
static struct {
unsigned char value;
const char *name;
} phases[] = {
{PHASE_DATAOUT, "DATAOUT"},
{PHASE_DATAIN, "DATAIN"},
{PHASE_CMDOUT, "CMDOUT"},
{PHASE_STATIN, "STATIN"},
{PHASE_MSGOUT, "MSGOUT"},
{PHASE_MSGIN, "MSGIN"},
{PHASE_UNKNOWN, "UNKNOWN"}
};
/**
* NCR5380_print_phase - show SCSI phase
* @instance: adapter to dump
*
* Print the current SCSI phase for debugging purposes
*/
static void NCR5380_print_phase(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char status;
int i;
status = NCR5380_read(STATUS_REG);
if (!(status & SR_REQ))
shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
else {
for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
(phases[i].value != (status & PHASE_MASK)); ++i)
;
shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
}
}
#endif
/**
* NCR5380_info - report driver and host information
* @instance: relevant scsi host instance
*
* For use as the host template info() handler.
*/
static const char *NCR5380_info(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
return hostdata->info;
}
/**
* NCR5380_init - initialise an NCR5380
* @instance: adapter to configure
* @flags: control flags
*
* Initializes *instance and corresponding 5380 chip,
* with flags OR'd into the initial flags value.
*
* Notes : I assume that the host, hostno, and id bits have been
* set correctly. I don't care about the irq and other fields.
*
* Returns 0 for success
*/
static int NCR5380_init(struct Scsi_Host *instance, int flags)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int i;
unsigned long deadline;
unsigned long accesses_per_ms;
instance->max_lun = 7;
hostdata->host = instance;
hostdata->id_mask = 1 << instance->this_id;
hostdata->id_higher_mask = 0;
for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
if (i > hostdata->id_mask)
hostdata->id_higher_mask |= i;
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
hostdata->dma_len = 0;
spin_lock_init(&hostdata->lock);
hostdata->connected = NULL;
hostdata->sensing = NULL;
INIT_LIST_HEAD(&hostdata->autosense);
INIT_LIST_HEAD(&hostdata->unissued);
INIT_LIST_HEAD(&hostdata->disconnected);
hostdata->flags = flags;
INIT_WORK(&hostdata->main_task, NCR5380_main);
hostdata->work_q = alloc_workqueue("ncr5380_%d",
WQ_UNBOUND | WQ_MEM_RECLAIM,
1, instance->host_no);
if (!hostdata->work_q)
return -ENOMEM;
snprintf(hostdata->info, sizeof(hostdata->info),
"%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
instance->hostt->name, instance->irq, hostdata->io_port,
hostdata->base, instance->can_queue, instance->cmd_per_lun,
instance->sg_tablesize, instance->this_id,
hostdata->flags & FLAG_DMA_FIXUP ? "DMA_FIXUP " : "",
hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
/* Calibrate register polling loop */
i = 0;
deadline = jiffies + 1;
do {
cpu_relax();
} while (time_is_after_jiffies(deadline));
deadline += msecs_to_jiffies(256);
do {
NCR5380_read(STATUS_REG);
++i;
cpu_relax();
} while (time_is_after_jiffies(deadline));
accesses_per_ms = i / 256;
hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
return 0;
}
/**
* NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
* @instance: adapter to check
*
* If the system crashed, it may have crashed with a connected target and
* the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
* currently established nexus, which we know nothing about. Failing that
* do a bus reset.
*
* Note that a bus reset will cause the chip to assert IRQ.
*
* Returns 0 if successful, otherwise -ENXIO.
*/
static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int pass;
for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
switch (pass) {
case 1:
case 3:
case 5:
shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
NCR5380_poll_politely(hostdata,
STATUS_REG, SR_BSY, 0, 5 * HZ);
break;
case 2:
shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
do_abort(instance);
break;
case 4:
shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
do_reset(instance);
/* Wait after a reset; the SCSI standard calls for
* 250ms, we wait 500ms to be on the safe side.
* But some Toshiba CD-ROMs need ten times that.
*/
if (hostdata->flags & FLAG_TOSHIBA_DELAY)
msleep(2500);
else
msleep(500);
break;
case 6:
shost_printk(KERN_ERR, instance, "bus locked solid\n");
return -ENXIO;
}
}
return 0;
}
/**
* NCR5380_exit - remove an NCR5380
* @instance: adapter to remove
*
* Assumes that no more work can be queued (e.g. by NCR5380_intr).
*/
static void NCR5380_exit(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
cancel_work_sync(&hostdata->main_task);
destroy_workqueue(hostdata->work_q);
}
/**
* complete_cmd - finish processing a command and return it to the SCSI ML
* @instance: the host instance
* @cmd: command to complete
*/
static void complete_cmd(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
if (hostdata->sensing == cmd) {
/* Autosense processing ends here */
if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
set_host_byte(cmd, DID_ERROR);
} else
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
hostdata->sensing = NULL;
}
hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
cmd->scsi_done(cmd);
}
/**
* NCR5380_queue_command - queue a command
* @instance: the relevant SCSI adapter
* @cmd: SCSI command
*
* cmd is added to the per-instance issue queue, with minor
* twiddling done to the host specific fields of cmd. If the
* main coroutine is not running, it is restarted.
*/
static int NCR5380_queue_command(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
unsigned long flags;
#if (NDEBUG & NDEBUG_NO_WRITE)
switch (cmd->cmnd[0]) {
case WRITE_6:
case WRITE_10:
shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
cmd->result = (DID_ERROR << 16);
cmd->scsi_done(cmd);
return 0;
}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
cmd->result = 0;
if (!NCR5380_acquire_dma_irq(instance))
return SCSI_MLQUEUE_HOST_BUSY;
spin_lock_irqsave(&hostdata->lock, flags);
/*
* Insert the cmd into the issue queue. Note that REQUEST SENSE
* commands are added to the head of the queue since any command will
* clear the contingent allegiance condition that exists and the
* sense data is only guaranteed to be valid while the condition exists.
*/
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",
cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
/* Kick off command processing */
queue_work(hostdata->work_q, &hostdata->main_task);
return 0;
}
static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
/* Caller does the locking needed to set & test these data atomically */
if (list_empty(&hostdata->disconnected) &&
list_empty(&hostdata->unissued) &&
list_empty(&hostdata->autosense) &&
!hostdata->connected &&
!hostdata->selecting) {
NCR5380_release_dma_irq(instance);
}
}
/**
* dequeue_next_cmd - dequeue a command for processing
* @instance: the scsi host instance
*
* Priority is given to commands on the autosense queue. These commands
* need autosense because of a CHECK CONDITION result.
*
* Returns a command pointer if a command is found for a target that is
* not already busy. Otherwise returns NULL.
*/
static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd;
struct scsi_cmnd *cmd;
if (hostdata->sensing || list_empty(&hostdata->autosense)) {
list_for_each_entry(ncmd, &hostdata->unissued, list) {
cmd = NCR5380_to_scmd(ncmd);
dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
list_del(&ncmd->list);
dsprintk(NDEBUG_QUEUES, instance,
"dequeue: removed %p from issue queue\n", cmd);
return cmd;
}
}
} else {
/* Autosense processing begins here */
ncmd = list_first_entry(&hostdata->autosense,
struct NCR5380_cmd, list);
list_del(&ncmd->list);
cmd = NCR5380_to_scmd(ncmd);
dsprintk(NDEBUG_QUEUES, instance,
"dequeue: removed %p from autosense queue\n", cmd);
scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
hostdata->sensing = cmd;
return cmd;
}
return NULL;
}
static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
if (hostdata->sensing == cmd) {
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
list_add(&ncmd->list, &hostdata->autosense);
hostdata->sensing = NULL;
} else
list_add(&ncmd->list, &hostdata->unissued);
}
/**
* NCR5380_main - NCR state machines
*
* NCR5380_main is a coroutine that runs as long as more work can
* be done on the NCR5380 host adapters in a system. Both
* NCR5380_queue_command() and NCR5380_intr() will try to start it
* in case it is not running.
*/
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;
int done;
do {
done = 1;
spin_lock_irq(&hostdata->lock);
while (!hostdata->connected && !hostdata->selecting) {
struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
if (!cmd)
break;
dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
/*
* 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.
*/
/*
* REQUEST SENSE commands are issued without tagged
* queueing, even on SCSI-II devices because the
* contingent allegiance condition exists for the
* entire unit.
*/
if (!NCR5380_select(instance, cmd)) {
dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
maybe_release_dma_irq(instance);
} else {
dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
"main: select failed, returning %p to queue\n", cmd);
requeue_cmd(instance, cmd);
}
}
if (hostdata->connected && !hostdata->dma_len) {
dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
NCR5380_information_transfer(instance);
done = 0;
}
spin_unlock_irq(&hostdata->lock);
if (!done)
cond_resched();
} while (!done);
}
/*
* NCR5380_dma_complete - finish DMA transfer
* @instance: the scsi host instance
*
* Called by the interrupt handler when DMA finishes or a phase
* mismatch occurs (which would end the DMA transfer).
*/
static void NCR5380_dma_complete(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int transferred;
unsigned char **data;
int *count;
int saved_data = 0, overrun = 0;
unsigned char p;
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;
dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
}
}
}
#ifdef CONFIG_SUN3
if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
instance->host_no);
BUG();
}
if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
(BASR_PHASE_MATCH | BASR_ACK)) {
pr_err("scsi%d: BASR %02x\n", instance->host_no,
NCR5380_read(BUS_AND_STATUS_REG));
pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
instance->host_no);
BUG();
}
#endif
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
hostdata->dma_len = 0;
data = (unsigned char **)&hostdata->connected->SCp.ptr;
count = &hostdata->connected->SCp.this_residual;
*data += transferred;
*count -= transferred;
if (hostdata->read_overruns) {
int cnt, toPIO;
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
cnt = toPIO = hostdata->read_overruns;
if (overrun) {
dsprintk(NDEBUG_DMA, instance,
"Got an input overrun, using saved byte\n");
*(*data)++ = saved_data;
(*count)--;
cnt--;
toPIO--;
}
if (toPIO > 0) {
dsprintk(NDEBUG_DMA, instance,
"Doing %d byte PIO to 0x%p\n", cnt, *data);
NCR5380_transfer_pio(instance, &p, &cnt, data);
*count -= toPIO - cnt;
}
}
}
}
/**
* NCR5380_intr - generic NCR5380 irq handler
* @irq: interrupt number
* @dev_id: device info
*
* Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
* from the disconnected queue, and restarting NCR5380_main()
* as required.
*
* The chip can assert IRQ in any of six different conditions. The IRQ flag
* is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
* Three of these six conditions are latched in the Bus and Status Register:
* - End of DMA (cleared by ending DMA Mode)
* - Parity error (cleared by reading RPIR)
* - Loss of BSY (cleared by reading RPIR)
* Two conditions have flag bits that are not latched:
* - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
* - Bus reset (non-maskable)
* The remaining condition has no flag bit at all:
* - Selection/reselection
*
* Hence, establishing the cause(s) of any interrupt is partly guesswork.
* In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
* claimed that "the design of the [DP8490] interrupt logic ensures
* interrupts will not be lost (they can be on the DP5380)."
* The L5380/53C80 datasheet from LOGIC Devices has more details.
*
* Checking for bus reset by reading RST is futile because of interrupt
* latency, but a bus reset will reset chip logic. Checking for parity error
* is unnecessary because that interrupt is never enabled. A Loss of BSY
* condition will clear DMA Mode. We can tell when this occurs because the
* the Busy Monitor interrupt is enabled together with DMA Mode.
*/
static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
{
struct Scsi_Host *instance = dev_id;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int handled = 0;
unsigned char basr;
unsigned long flags;
spin_lock_irqsave(&hostdata->lock, flags);
basr = NCR5380_read(BUS_AND_STATUS_REG);
if (basr & BASR_IRQ) {
unsigned char mr = NCR5380_read(MODE_REG);
unsigned char sr = NCR5380_read(STATUS_REG);
dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
irq, basr, sr, mr);
if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
/* Probably End of DMA, Phase Mismatch or Loss of BSY.
* We ack IRQ after clearing Mode Register. Workarounds
* for End of DMA errata need to happen in DMA Mode.
*/
dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
if (hostdata->connected) {
NCR5380_dma_complete(instance);
queue_work(hostdata->work_q, &hostdata->main_task);
} else {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
} else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
(sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
/* Probably reselected */
NCR5380_write(SELECT_ENABLE_REG, 0);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
if (!hostdata->connected) {
NCR5380_reselect(instance);
queue_work(hostdata->work_q, &hostdata->main_task);
}
if (!hostdata->connected)
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
} else {
/* Probably Bus Reset */
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
}
handled = 1;
} else {
dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
}
spin_unlock_irqrestore(&hostdata->lock, flags);
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 cmd if selection failed but should be retried,
* NULL if selection failed and should not be retried, or
* NULL if selection succeeded (hostdata->connected == cmd).
*
* 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 struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char tmp[3], phase;
unsigned char *data;
int len;
int err;
NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
instance->this_id);
/*
* Arbitration and selection phases are slow and involve dropping the
* lock, so we have to watch out for EH. An exception handler may
* change 'selecting' to NULL. This function will then return NULL
* so that the caller will forget about 'cmd'. (During information
* transfer phases, EH may change 'connected' to NULL.)
*/
hostdata->selecting = cmd;
/*
* Set the phase bits to 0, otherwise the NCR5380 won't drive the
* data bus during SELECTION.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
/*
* Start arbitration.
*/
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(MODE_REG, MR_ARBITRATE);
/* The chip now waits for BUS FREE phase. Then after the 800 ns
* Bus Free Delay, arbitration will begin.
*/
spin_unlock_irq(&hostdata->lock);
err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
ICR_ARBITRATION_PROGRESS, HZ);
spin_lock_irq(&hostdata->lock);
if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
/* Reselection interrupt */
goto out;
}
if (!hostdata->selecting) {
/* Command was aborted */
NCR5380_write(MODE_REG, MR_BASE);
goto out;
}
if (err < 0) {
NCR5380_write(MODE_REG, MR_BASE);
shost_printk(KERN_ERR, instance,
"select: arbitration timeout\n");
goto out;
}
spin_unlock_irq(&hostdata->lock);
/* The SCSI-2 arbitration delay is 2.4 us */
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)) {
NCR5380_write(MODE_REG, MR_BASE);
dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
spin_lock_irq(&hostdata->lock);
goto out;
}
/* 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);
/*
* Again, bus clear + bus settle time is 1.2us, however, this is
* a minimum so we'll udelay ceil(1.2)
*/
if (hostdata->flags & FLAG_TOSHIBA_DELAY)
udelay(15);
else
udelay(2);
spin_lock_irq(&hostdata->lock);
/* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
goto out;
if (!hostdata->selecting) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
goto out;
}
dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
/*
* 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 << scmd_id(cmd)));
/*
* 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);
NCR5380_write(MODE_REG, MR_BASE);
/*
* Reselect interrupts must be turned off prior to the dropping of BSY,
* otherwise we will trigger an interrupt.
*/
NCR5380_write(SELECT_ENABLE_REG, 0);
spin_unlock_irq(&hostdata->lock);
/*
* 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.
*/
udelay(1);
dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
/*
* The SCSI specification calls for a 250 ms timeout for the actual
* selection.
*/
err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
msecs_to_jiffies(250));
if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
spin_lock_irq(&hostdata->lock);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_reselect(instance);
if (!hostdata->connected)
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
goto out;
}
if (err < 0) {
spin_lock_irq(&hostdata->lock);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/* Can't touch cmd if it has been reclaimed by the scsi ML */
if (hostdata->selecting) {
cmd->result = DID_BAD_TARGET << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
cmd = NULL;
}
goto out;
}
/*
* 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
*/
udelay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
/*
* 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.
*/
/* Wait for start of REQ/ACK handshake */
err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
spin_lock_irq(&hostdata->lock);
if (err < 0) {
shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
goto out;
}
if (!hostdata->selecting) {
do_abort(instance);
goto out;
}
dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
scmd_id(cmd));
tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
len = 1;
data = tmp;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (len) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
cmd = NULL;
goto out;
}
dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
hostdata->connected = cmd;
hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
initialize_SCp(cmd);
cmd = NULL;
out:
if (!hostdata->selecting)
return NULL;
hostdata->selecting = NULL;
return cmd;
}
/*
* 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
* is in same phase.
*
* 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)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char p = *phase, tmp;
int c = *count;
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
*/
if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
break;
dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
/* Check for phase mismatch */
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
NCR5380_dprint_phase(NDEBUG_PIO, instance);
break;
}
/* 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);
++d;
/*
* 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);
}
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
break;
dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
/*
* 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);
dsprintk(NDEBUG_PIO, instance, "residual %d\n", 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 applies if
* we're in MSG IN, DATA IN or STATUS and all bytes have been received.
*/
if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
*phase = tmp & PHASE_MASK;
else
*phase = PHASE_UNKNOWN;
if (!c || (*phase == p))
return 0;
else
return -1;
}
/**
* do_reset - issue a reset command
* @instance: adapter to reset
*
* Issue a reset sequence to the NCR5380 and try and get the bus
* back into sane shape.
*
* This clears the reset interrupt flag because there may be no handler for
* it. When the driver is initialized, the NCR5380_intr() handler has not yet
* been installed. And when in EH we may have released the ST DMA interrupt.
*/
static void do_reset(struct Scsi_Host *instance)
{
struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
unsigned long flags;
local_irq_save(flags);
NCR5380_write(TARGET_COMMAND_REG,
PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
udelay(50);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
local_irq_restore(flags);
}
/**
* do_abort - abort the currently established nexus by going to
* MESSAGE OUT phase and sending an ABORT message.
* @instance: relevant scsi host instance
*
* Returns 0 on success, -1 on failure.
*/
static int do_abort(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char *msgptr, phase, tmp;
int len;
int rc;
/* 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.
*/
rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
if (rc < 0)
goto timeout;
tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
if (tmp != PHASE_MSGOUT) {
NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
if (rc < 0)
goto timeout;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
}
tmp = ABORT;
msgptr = &tmp;
len = 1;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &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;
timeout:
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return -1;
}
/*
* 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
* is in same phase.
*
* 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)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int c = *count;
unsigned char p = *phase;
unsigned char *d = *data;
unsigned char tmp;
int result = 0;
if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
*phase = tmp;
return -1;
}
hostdata->connected->SCp.phase = p;
if (p & SR_IO) {
if (hostdata->read_overruns)
c -= hostdata->read_overruns;
else if (hostdata->flags & FLAG_DMA_FIXUP)
--c;
}
dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
(p & SR_IO) ? "receive" : "send", c, d);
#ifdef CONFIG_SUN3
/* send start chain */
sun3scsi_dma_start(c, *data);
#endif
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
MR_ENABLE_EOP_INTR);
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.
*/
if (p & SR_IO)
result = NCR5380_dma_recv_setup(hostdata, d, c);
else
result = NCR5380_dma_send_setup(hostdata, d, c);
}
/*
* On the PAS16 at least I/O recovery delays are not needed here.
* Everyone else seems to want them.
*/
if (p & SR_IO) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_io_delay(1);
NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
} else {
NCR5380_io_delay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_io_delay(1);
NCR5380_write(START_DMA_SEND_REG, 0);
NCR5380_io_delay(1);
}
#ifdef CONFIG_SUN3
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
sun3_dma_active = 1;
#endif
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!
*/
if (p & SR_IO)
result = NCR5380_dma_recv_setup(hostdata, d, c);
else
result = NCR5380_dma_send_setup(hostdata, d, c);
}
/* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
if (result < 0)
return result;
/* For real DMA, result is the byte count. DMA interrupt is expected. */
if (result > 0) {
hostdata->dma_len = result;
return 0;
}
/* The result is zero iff pseudo DMA send/receive was completed. */
hostdata->dma_len = c;
/*
* A note regarding the DMA errata workarounds for early NMOS silicon.
*
* For DMA sends, we want to wait until the last byte has been
* transferred out over the bus before we turn off DMA mode. Alas, there
* seems to be no terribly good way of doing this on a 5380 under all
* conditions. For non-scatter-gather operations, we can wait until REQ
* and ACK both go false, or until a phase mismatch occurs. Gather-sends
* are nastier, since the device will be expecting more data than we
* are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
* could test Last Byte Sent to assure transfer (I imagine this is precisely
* why this signal was added to the newer chips) but on the older 538[01]
* this signal does not exist. The workaround for this lack is a watchdog;
* we bail out of the wait-loop after a modest amount of wait-time if
* the usual exit conditions are not met. Not a terribly clean or
* correct solution :-%
*
* DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
* If the chip is in DMA receive mode, it will respond to a target's
* REQ by latching the SCSI data into the INPUT DATA register and asserting
* ACK, even if it has _already_ been notified by the DMA controller that
* the current DMA transfer has completed! If the NCR5380 is then taken
* out of DMA mode, this already-acknowledged byte is lost. This is
* not a problem for "one DMA transfer per READ command", because
* the situation will never arise... either all of the data is DMA'ed
* properly, or the target switches to MESSAGE IN phase to signal a
* disconnection (either operation bringing the DMA to a clean halt).
* However, in order to handle scatter-receive, we must work around the
* problem. The chosen fix is to DMA fewer bytes, then check for the
* condition before taking the NCR5380 out of DMA mode. One or two extra
* bytes are transferred via PIO as necessary to fill out the original
* request.
*/
if (hostdata->flags & FLAG_DMA_FIXUP) {
if (p & SR_IO) {
/*
* The workaround was to transfer fewer bytes than we
* intended to with the pseudo-DMA read function, wait for
* the chip to latch the last byte, read it, and then disable
* pseudo-DMA mode.
*
* After REQ is asserted, the NCR5380 asserts DRQ and ACK.
* REQ is deasserted when ACK is asserted, and not reasserted
* until ACK goes false. Since the NCR5380 won't lower ACK
* until DACK is asserted, which won't happen unless we twiddle
* the DMA port or we take the NCR5380 out of DMA mode, we
* can guarantee that we won't handshake another extra
* byte.
*/
if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ, BASR_DRQ, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
}
if (NCR5380_poll_politely(hostdata, STATUS_REG,
SR_REQ, 0, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
}
d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
} else {
/*
* Wait for the last byte to be sent. If REQ is being asserted for
* the byte we're interested, we'll ACK it and it will go false.
*/
if (NCR5380_poll_politely2(hostdata,
BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
}
}
}
NCR5380_dma_complete(instance);
return result;
}
/*
* 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)
__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char msgout = NOP;
int sink = 0;
int len;
int transfersize;
unsigned char *data;
unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
struct scsi_cmnd *cmd;
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
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) {
phase = (tmp & PHASE_MASK);
if (phase != old_phase) {
old_phase = phase;
NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
}
#ifdef CONFIG_SUN3
if (phase == PHASE_CMDOUT &&
sun3_dma_setup_done != cmd) {
int count;
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);
}
count = sun3scsi_dma_xfer_len(hostdata, cmd);
if (count > 0) {
if (rq_data_dir(cmd->request))
sun3scsi_dma_send_setup(hostdata,
cmd->SCp.ptr, count);
else
sun3scsi_dma_recv_setup(hostdata,
cmd->SCp.ptr, count);
sun3_dma_setup_done = cmd;
}
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
}
#endif /* CONFIG_SUN3 */
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:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
hostdata->connected = NULL;
return;
#endif
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);
dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
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.
*/
transfersize = 0;
if (!cmd->device->borken)
transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
if (transfersize > 0) {
len = transfersize;
if (NCR5380_transfer_dma(instance, &phase,
&len, (unsigned char **)&cmd->SCp.ptr)) {
/*
* If the watchdog timer fires, all future
* accesses to this device will use the
* polled-IO.
*/
scmd_printk(KERN_INFO, cmd,
"switching to slow handshake\n");
cmd->device->borken = 1;
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
/* XXX - need to source or sink data here, as appropriate */
}
} else {
/* Transfer a small chunk so that the
* irq mode lock is not held too long.
*/
transfersize = min(cmd->SCp.this_residual,
NCR5380_PIO_CHUNK_SIZE);
len = transfersize;
NCR5380_transfer_pio(instance, &phase, &len,
(unsigned char **)&cmd->SCp.ptr);
cmd->SCp.this_residual -= transfersize - len;
}
#ifdef CONFIG_SUN3
if (sun3_dma_setup_done == cmd)
sun3_dma_setup_done = NULL;
#endif
return;
case PHASE_MSGIN:
len = 1;
data = &tmp;
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Message = tmp;
switch (tmp) {
case ABORT:
case COMMAND_COMPLETE:
/* Accept message by clearing ACK */
sink = 1;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dsprintk(NDEBUG_QUEUES, instance,
"COMMAND COMPLETE %p target %d lun %llu\n",
cmd, scmd_id(cmd), cmd->device->lun);
hostdata->connected = NULL;
cmd->result &= ~0xffff;
cmd->result |= cmd->SCp.Status;
cmd->result |= cmd->SCp.Message << 8;
if (cmd->cmnd[0] == REQUEST_SENSE)
complete_cmd(instance, cmd);
else {
if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
cmd);
list_add_tail(&ncmd->list,
&hostdata->autosense);
} else
complete_cmd(instance, cmd);
}
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
maybe_release_dma_irq(instance);
return;
case MESSAGE_REJECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
switch (hostdata->last_message) {
case HEAD_OF_QUEUE_TAG:
case ORDERED_QUEUE_TAG:
case SIMPLE_QUEUE_TAG:
cmd->device->simple_tags = 0;
hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
break;
default:
break;
}
break;
case DISCONNECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
hostdata->connected = NULL;
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);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
return;
/*
* The SCSI data pointer is *IMPLICITLY* saved on a disconnect
* operation, in violation of the SCSI spec so we can safely
* ignore SAVE/RESTORE pointers calls.
*
* Unfortunately, some disks violate the SCSI spec and
* don't issue the required SAVE_POINTERS message before
* disconnecting, and we have to break spec to remain
* compatible.
*/
case SAVE_POINTERS:
case RESTORE_POINTERS:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
break;
case EXTENDED_MESSAGE:
/*
* Start the message buffer with the EXTENDED_MESSAGE
* byte, since spi_print_msg() wants the whole thing.
*/
extended_msg[0] = EXTENDED_MESSAGE;
/* Accept first byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
spin_unlock_irq(&hostdata->lock);
dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
len = 2;
data = extended_msg + 1;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
(int)extended_msg[1],
(int)extended_msg[2]);
if (!len && extended_msg[1] > 0 &&
extended_msg[1] <= sizeof(extended_msg) - 2) {
/* Accept third byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
len = extended_msg[1] - 1;
data = extended_msg + 3;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
len);
switch (extended_msg[2]) {
case EXTENDED_SDTR:
case EXTENDED_WDTR:
tmp = 0;
}
} else if (len) {
shost_printk(KERN_ERR, instance, "error receiving extended message\n");
tmp = 0;
} else {
shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
extended_msg[2], extended_msg[1]);
tmp = 0;
}
spin_lock_irq(&hostdata->lock);
if (!hostdata->connected)
return;
/* Fall through to reject message */
/*
* If we get something weird that we aren't expecting,
* reject it.
*/
default:
if (tmp == EXTENDED_MESSAGE)
scmd_printk(KERN_INFO, cmd,
"rejecting unknown extended message code %02x, length %d\n",
extended_msg[2], extended_msg[1]);
else if (tmp)
scmd_printk(KERN_INFO, cmd,
"rejecting unknown message code %02x\n",
tmp);
msgout = MESSAGE_REJECT;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
break;
} /* switch (tmp) */
break;
case PHASE_MSGOUT:
len = 1;
data = &msgout;
hostdata->last_message = msgout;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (msgout == ABORT) {
hostdata->connected = NULL;
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
maybe_release_dma_irq(instance);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return;
}
msgout = NOP;
break;
case PHASE_CMDOUT:
len = cmd->cmd_len;
data = cmd->cmnd;
/*
* XXX for performance reasons, on machines with a
* PSEUDO-DMA architecture we should probably
* use the dma transfer function.
*/
NCR5380_transfer_pio(instance, &phase, &len, &data);
break;
case PHASE_STATIN:
len = 1;
data = &tmp;
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Status = tmp;
break;
default:
shost_printk(KERN_ERR, instance, "unknown phase\n");
NCR5380_dprint(NDEBUG_ANY, instance);
} /* switch(phase) */
} else {
spin_unlock_irq(&hostdata->lock);
NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
spin_lock_irq(&hostdata->lock);
}
}
}
/*
* Function : void NCR5380_reselect (struct Scsi_Host *instance)
*
* Purpose : does reselection, initializing the instance->connected
* field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
* nexus has been reestablished,
*
* Inputs : instance - this instance of the NCR5380.
*/
static void NCR5380_reselect(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char target_mask;
unsigned char lun;
unsigned char msg[3];
struct NCR5380_cmd *ncmd;
struct scsi_cmnd *tmp;
/*
* Disable arbitration, etc. since the host adapter obviously
* lost, and tell an interrupted NCR5380_select() to restart.
*/
NCR5380_write(MODE_REG, MR_BASE);
target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
/*
* At this point, we have detected that our SCSI ID is on the bus,
* SEL is true and BSY was false for at least one bus settle delay
* (400 ns).
*
* We must assert BSY ourselves, until the target drops the SEL
* signal.
*/
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return;
}
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/*
* Wait for target to go into MSGIN.
*/
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
do_abort(instance);
return;
}
#ifdef CONFIG_SUN3
/* acknowledge toggle to MSGIN */
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
/* peek at the byte without really hitting the bus */
msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
#else
{
int len = 1;
unsigned char *data = msg;
unsigned char phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (len) {
do_abort(instance);
return;
}
}
#endif /* CONFIG_SUN3 */
if (!(msg[0] & 0x80)) {
shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
spi_print_msg(msg);
printk("\n");
do_abort(instance);
return;
}
lun = msg[0] & 0x07;
/*
* We need to add code for SCSI-II to track which devices have
* I_T_L_Q nexuses established, and which have simple I_T_L
* nexuses so we can chose to do additional data transfer.
*/
/*
* Find the command corresponding to the I_T_L or I_T_L_Q nexus we
* just reestablished, and remove it from the disconnected queue.
*/
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;
}
}
if (tmp) {
dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
"reselect: removed %p from disconnected queue\n", tmp);
} else {
shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
target_mask, lun);
/*
* Since we have an established nexus that we can't do anything
* with, we must abort it.
*/
do_abort(instance);
return;
}
#ifdef CONFIG_SUN3
if (sun3_dma_setup_done != tmp) {
int count;
if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
++tmp->SCp.buffer;
--tmp->SCp.buffers_residual;
tmp->SCp.this_residual = tmp->SCp.buffer->length;
tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
}
count = sun3scsi_dma_xfer_len(hostdata, tmp);
if (count > 0) {
if (rq_data_dir(tmp->request))
sun3scsi_dma_send_setup(hostdata,
tmp->SCp.ptr, count);
else
sun3scsi_dma_recv_setup(hostdata,
tmp->SCp.ptr, count);
sun3_dma_setup_done = tmp;
}
}
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
#endif /* CONFIG_SUN3 */
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
hostdata->connected = tmp;
dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
scmd_id(tmp), tmp->device->lun);
}
/**
* list_find_cmd - test for presence of a command in a linked list
* @haystack: list of commands
* @needle: command to search for
*/
static bool list_find_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
struct NCR5380_cmd *ncmd;
list_for_each_entry(ncmd, haystack, list)
if (NCR5380_to_scmd(ncmd) == needle)
return true;
return false;
}
/**
* list_remove_cmd - remove a command from linked list
* @haystack: list of commands
* @needle: command to remove
*/
static bool list_del_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
if (list_find_cmd(haystack, needle)) {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
list_del(&ncmd->list);
return true;
}
return false;
}
/**
* NCR5380_abort - scsi host eh_abort_handler() method
* @cmd: the command to be aborted
*
* Try to abort a given command by removing it from queues and/or sending
* the target an abort message. This may not succeed in causing a target
* to abort the command. Nonetheless, the low-level driver must forget about
* the command because the mid-layer reclaims it and it may be re-issued.
*
* The normal path taken by a command is as follows. For EH we trace this
* same path to locate and abort the command.
*
* unissued -> selecting -> [unissued -> selecting ->]... connected ->
* [disconnected -> connected ->]...
* [autosense -> connected ->] done
*
* If cmd was not found at all then presumably it has already been completed,
* in which case return SUCCESS to try to avoid further EH measures.
*
* If the command has not completed yet, we must not fail to find it.
* We have no option but to forget the aborted command (even if it still
* lacks sense data). The mid-layer may re-issue a command that is in error
* recovery (see scsi_send_eh_cmnd), but the logic and data structures in
* this driver are such that a command can appear on one queue only.
*
* The lock protects driver data structures, but EH handlers also use it
* to serialize their own execution and prevent their own re-entry.
*/
static int NCR5380_abort(struct scsi_cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long flags;
int result = SUCCESS;
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
scmd_printk(KERN_INFO, cmd, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
if (list_del_cmd(&hostdata->unissued, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from issue queue\n", cmd);
cmd->result = DID_ABORT << 16;
cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
goto out;
}
if (hostdata->selecting == cmd) {
dsprintk(NDEBUG_ABORT, instance,
"abort: cmd %p == selecting\n", cmd);
hostdata->selecting = NULL;
cmd->result = DID_ABORT << 16;
complete_cmd(instance, cmd);
goto out;
}
if (list_del_cmd(&hostdata->disconnected, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from disconnected list\n", cmd);
/* Can't call NCR5380_select() and send ABORT because that
* means releasing the lock. Need a bus reset.
*/
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
hostdata->dma_len = 0;
if (do_abort(instance)) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
complete_cmd(instance, cmd);
goto out;
}
if (list_del_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from sense queue\n", cmd);
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
}
out:
if (result == FAILED)
dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
else
dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
queue_work(hostdata->work_q, &hostdata->main_task);
maybe_release_dma_irq(instance);
spin_unlock_irqrestore(&hostdata->lock, flags);
return result;
}
/**
* NCR5380_host_reset - reset the SCSI host
* @cmd: SCSI command undergoing EH
*
* Returns SUCCESS
*/
static int NCR5380_host_reset(struct scsi_cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int i;
unsigned long flags;
struct NCR5380_cmd *ncmd;
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
scmd_printk(KERN_INFO, cmd, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
do_reset(instance);
/* reset NCR registers */
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
/* After the reset, there are no more connected or disconnected commands
* and no busy units; so clear the low-level status here to avoid
* conflicts when the mid-level code tries to wake up the affected
* commands!
*/
if (list_del_cmd(&hostdata->unissued, cmd)) {
cmd->result = DID_RESET << 16;
cmd->scsi_done(cmd);
}
if (hostdata->selecting) {
hostdata->selecting->result = DID_RESET << 16;
complete_cmd(instance, hostdata->selecting);
hostdata->selecting = NULL;
}
list_for_each_entry(ncmd, &hostdata->disconnected, list) {
struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
set_host_byte(cmd, DID_RESET);
complete_cmd(instance, cmd);
}
INIT_LIST_HEAD(&hostdata->disconnected);
list_for_each_entry(ncmd, &hostdata->autosense, list) {
struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
set_host_byte(cmd, DID_RESET);
cmd->scsi_done(cmd);
}
INIT_LIST_HEAD(&hostdata->autosense);
if (hostdata->connected) {
set_host_byte(hostdata->connected, DID_RESET);
complete_cmd(instance, hostdata->connected);
hostdata->connected = NULL;
}
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
hostdata->dma_len = 0;
queue_work(hostdata->work_q, &hostdata->main_task);
maybe_release_dma_irq(instance);
spin_unlock_irqrestore(&hostdata->lock, flags);
return SUCCESS;
}
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