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linux-next/drivers/scsi/NCR5380.c
Finn Thain 8d5dbec3bc ncr5380: Call scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() as and when appropriate 
This bug causes the wrong command to have its sense pointer overwritten,
which sometimes leads to a NULL pointer deref. Fix this by checking which
command is being requeued before restoring the scsi_eh_save data.

It turns out that some targets will disconnect a REQUEST SENSE command.
The autosense algorithm doesn't anticipate this. Hence multiple commands
can end up undergoing autosense simultaneously, and they will all try to
use the same scsi_eh_save struct, which won't work. Defer autosense when
the scsi_eh_save storage is in use by another command.

Fixes: f27db8eb98 ("ncr5380: Fix autosense bugs")
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01 09:38:58 -05:00

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/*
* 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.
*/
/*
* Further development / testing that should be done :
* 1. Cleanup the NCR5380_transfer_dma function and DMA operation complete
* code so that everything does the same thing that's done at the
* end of a pseudo-DMA read operation.
*
* 2. Fix REAL_DMA (interrupt driven, polled works fine) -
* basically, transfer size needs to be reduced by one
* and the last byte read as is done with PSEUDO_DMA.
*
* 4. Test SCSI-II tagged queueing (I have no devices which support
* tagged queueing)
*/
#ifndef notyet
#undef REAL_DMA
#endif
#ifdef BOARD_REQUIRES_NO_DELAY
#define io_recovery_delay(x)
#else
#define io_recovery_delay(x) udelay(x)
#endif
/*
* 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 control options :
* AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
* defined.
*
* AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
* for commands that return with a CHECK CONDITION status.
*
* DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
* transceivers.
*
* DONT_USE_INTR - if defined, never use interrupts, even if we probe or
* override-configure an IRQ.
*
* PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
*
* REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
*
* REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
* rely on phase mismatch and EOP interrupts to determine end
* of phase.
*
* 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
* REAL functions :
* NCR5380_REAL_DMA should be defined if real DMA is to be used.
* Note that the DMA setup functions should return the number of bytes
* that they were able to program the controller for.
*
* Also note that generic i386/PC versions of these macros are
* available as NCR5380_i386_dma_write_setup,
* NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
*
* NCR5380_dma_write_setup(instance, src, count) - initialize
* NCR5380_dma_read_setup(instance, dst, count) - initialize
* NCR5380_dma_residual(instance); - residual count
*
* PSEUDO functions :
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID. If the
* driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
* possible) function may be used.
*/
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
* @instance: controller to poll
* @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 Scsi_Host *instance,
int reg1, int bit1, int val1,
int reg2, int bit2, int val2, int wait)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long deadline = jiffies + wait;
unsigned long n;
/* Busy-wait for up to 10 ms */
n = min(10000U, jiffies_to_usecs(wait));
n *= hostdata->accesses_per_ms;
n /= 2000;
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;
}
static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
int reg, int bit, int val, int wait)
{
return NCR5380_poll_politely2(instance, reg, bit, val,
reg, bit, val, wait);
}
#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_ATN, "ATN"},
{BASR_ACK, "ACK"},
{0, NULL}
},
icrs[] = {
{ICR_ASSERT_RST, "ASSERT RST"},
{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, "MODE BLOCK DMA"},
{MR_TARGET, "MODE TARGET"},
{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
{MR_ENABLE_EOP_INTR, "MODE EOP INTR"},
{MR_MONITOR_BSY, "MODE MONITOR BSY"},
{MR_DMA_MODE, "MODE DMA"},
{MR_ARBITRATE, "MODE ARBITRATION"},
{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)
{
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("STATUS_REG: %02x ", status);
for (i = 0; signals[i].mask; ++i)
if (status & signals[i].mask)
printk(",%s", signals[i].name);
printk("\nBASR: %02x ", basr);
for (i = 0; basrs[i].mask; ++i)
if (basr & basrs[i].mask)
printk(",%s", basrs[i].name);
printk("\nICR: %02x ", icr);
for (i = 0; icrs[i].mask; ++i)
if (icr & icrs[i].mask)
printk(",%s", icrs[i].name);
printk("\nMODE: %02x ", mr);
for (i = 0; mrs[i].mask; ++i)
if (mr & mrs[i].mask)
printk(",%s", mrs[i].name);
printk("\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)
{
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
static int probe_irq __initdata;
/**
* probe_intr - helper for IRQ autoprobe
* @irq: interrupt number
* @dev_id: unused
* @regs: unused
*
* Set a flag to indicate the IRQ in question was received. This is
* used by the IRQ probe code.
*/
static irqreturn_t __init probe_intr(int irq, void *dev_id)
{
probe_irq = irq;
return IRQ_HANDLED;
}
/**
* NCR5380_probe_irq - find the IRQ of an NCR5380
* @instance: NCR5380 controller
* @possible: bitmask of ISA IRQ lines
*
* Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
* and then looking to see what interrupt actually turned up.
*/
static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
int possible)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long timeout;
int trying_irqs, i, mask;
for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1)
if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
trying_irqs |= mask;
timeout = jiffies + msecs_to_jiffies(250);
probe_irq = NO_IRQ;
/*
* A interrupt is triggered whenever BSY = false, SEL = true
* and a bit set in the SELECT_ENABLE_REG is asserted on the
* SCSI bus.
*
* Note that the bus is only driven when the phase control signals
* (I/O, C/D, and MSG) match those in the TCR, so we must reset that
* to zero.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
while (probe_irq == NO_IRQ && time_before(jiffies, timeout))
schedule_timeout_uninterruptible(1);
NCR5380_write(SELECT_ENABLE_REG, 0);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
for (i = 1, mask = 2; i < 16; ++i, mask <<= 1)
if (trying_irqs & mask)
free_irq(i, NULL);
return probe_irq;
}
/**
* NCR58380_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;
}
static void prepare_info(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
snprintf(hostdata->info, sizeof(hostdata->info),
"%s, io_port 0x%lx, n_io_port %d, "
"base 0x%lx, irq %d, "
"can_queue %d, cmd_per_lun %d, "
"sg_tablesize %d, this_id %d, "
"flags { %s%s%s}, "
"options { %s} ",
instance->hostt->name, instance->io_port, instance->n_io_port,
instance->base, instance->irq,
instance->can_queue, instance->cmd_per_lun,
instance->sg_tablesize, instance->this_id,
hostdata->flags & FLAG_NO_DMA_FIXUP ? "NO_DMA_FIXUP " : "",
hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "",
#ifdef AUTOPROBE_IRQ
"AUTOPROBE_IRQ "
#endif
#ifdef DIFFERENTIAL
"DIFFERENTIAL "
#endif
#ifdef REAL_DMA
"REAL_DMA "
#endif
#ifdef REAL_DMA_POLL
"REAL_DMA_POLL "
#endif
#ifdef PARITY
"PARITY "
#endif
#ifdef PSEUDO_DMA
"PSEUDO_DMA "
#endif
"");
}
#ifdef PSEUDO_DMA
static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
char *buffer, int length)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
hostdata->spin_max_r = 0;
hostdata->spin_max_w = 0;
return 0;
}
static int __maybe_unused NCR5380_show_info(struct seq_file *m,
struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
seq_printf(m, "Highwater I/O busy spin counts: write %d, read %d\n",
hostdata->spin_max_w, hostdata->spin_max_r);
return 0;
}
#endif
/**
* 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;
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;
#ifdef REAL_DMA
hostdata->dmalen = 0;
#endif
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;
prepare_info(instance);
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));
hostdata->accesses_per_ms = i / 256;
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(instance,
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;
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;
}
/**
* 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");
} else {
dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
"main: select failed, returning %p to queue\n", cmd);
requeue_cmd(instance, cmd);
}
}
if (hostdata->connected
#ifdef REAL_DMA
&& !hostdata->dmalen
#endif
) {
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);
}
#ifndef DONT_USE_INTR
/**
* 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 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 defined(REAL_DMA)
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");
int transferred;
if (!hostdata->connected)
panic("scsi%d : DMA interrupt with no connected cmd\n",
instance->hostno);
transferred = hostdata->dmalen - NCR5380_dma_residual(instance);
hostdata->connected->SCp.this_residual -= transferred;
hostdata->connected->SCp.ptr += transferred;
hostdata->dmalen = 0;
/* FIXME: we need to poll briefly then defer a workqueue task ! */
NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2 * HZ);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else
#endif /* REAL_DMA */
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");
}
handled = 1;
} else {
shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
}
spin_unlock_irqrestore(&hostdata->lock, flags);
return IRQ_RETVAL(handled);
}
#endif
/*
* 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)
{
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(instance, 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(instance, 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.
*
* 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 */
err = NCR5380_poll_politely(instance, 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;
cmd->tag = 0;
/* Send message(s) */
data = tmp;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
/* XXX need to handle errors here */
hostdata->connected = cmd;
hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
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)
{
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(instance, 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(instance,
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)
{
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)
{
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(instance, 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(instance, 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;
}
#if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
/*
* 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);
register int c = *count;
register unsigned char p = *phase;
register unsigned char *d = *data;
unsigned char tmp;
int foo;
#if defined(REAL_DMA_POLL)
int cnt, toPIO;
unsigned char saved_data = 0, overrun = 0, residue;
#endif
if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
*phase = tmp;
return -1;
}
#if defined(REAL_DMA) || defined(REAL_DMA_POLL)
if (p & SR_IO) {
if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS))
c -= 2;
}
hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
(p & SR_IO) ? "receive" : "send", c, *data);
#endif
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
#ifdef REAL_DMA
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
MR_ENABLE_EOP_INTR);
#elif defined(REAL_DMA_POLL)
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
#else
/*
* Note : on my sample board, watch-dog timeouts occurred when interrupts
* were not disabled for the duration of a single DMA transfer, from
* before the setting of DMA mode to after transfer of the last byte.
*/
if (hostdata->flags & FLAG_NO_DMA_FIXUP)
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
MR_ENABLE_EOP_INTR);
else
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
#endif /* def REAL_DMA */
dprintk(NDEBUG_DMA, "scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG));
/*
* On the PAS16 at least I/O recovery delays are not needed here.
* Everyone else seems to want them.
*/
if (p & SR_IO) {
io_recovery_delay(1);
NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
} else {
io_recovery_delay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
io_recovery_delay(1);
NCR5380_write(START_DMA_SEND_REG, 0);
io_recovery_delay(1);
}
#if defined(REAL_DMA_POLL)
do {
tmp = NCR5380_read(BUS_AND_STATUS_REG);
} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
/*
* At this point, either we've completed DMA, or we have a phase mismatch,
* or we've unexpectedly lost BUSY (which is a real error).
*
* 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 N-2 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 (p & SR_IO) {
if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS)) {
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_REGISTER);
overrun = 1;
}
}
} else {
int limit = 100;
while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
if (!(tmp & BASR_PHASE_MATCH))
break;
if (--limit < 0)
break;
}
}
dsprintk(NDEBUG_DMA, "polled DMA transfer complete, basr 0x%02x, sr 0x%02x\n",
tmp, NCR5380_read(STATUS_REG));
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
residue = NCR5380_dma_residual(instance);
c -= residue;
*count -= c;
*data += c;
*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS) &&
*phase == p && (p & SR_IO) && residue == 0) {
if (overrun) {
dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
**data = saved_data;
*data += 1;
*count -= 1;
cnt = toPIO = 1;
} else {
printk("No overrun??\n");
cnt = toPIO = 2;
}
dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%X\n", cnt, *data);
NCR5380_transfer_pio(instance, phase, &cnt, data);
*count -= toPIO - cnt;
}
dprintk(NDEBUG_DMA, "Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count));
return 0;
#elif defined(REAL_DMA)
return 0;
#else /* defined(REAL_DMA_POLL) */
if (p & SR_IO) {
foo = NCR5380_pread(instance, d,
hostdata->flags & FLAG_NO_DMA_FIXUP ? c : c - 1);
if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
/*
* We can't disable DMA mode after successfully transferring
* what we plan to be the last byte, since that would open up
* a race condition where if the target asserted REQ before
* we got the DMA mode reset, the NCR5380 would have latched
* an additional byte into the INPUT DATA register and we'd
* have dropped it.
*
* The workaround was to transfer one 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(instance, BUS_AND_STATUS_REG,
BASR_DRQ, BASR_DRQ, HZ) < 0) {
foo = -1;
shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
}
if (NCR5380_poll_politely(instance, STATUS_REG,
SR_REQ, 0, HZ) < 0) {
foo = -1;
shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
}
d[c - 1] = NCR5380_read(INPUT_DATA_REG);
}
} else {
foo = NCR5380_pwrite(instance, d, c);
if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
/*
* 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(instance,
BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
foo = -1;
shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
}
}
}
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
*data = d + c;
*count = 0;
*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
return foo;
#endif /* def REAL_DMA */
}
#endif /* defined(REAL_DMA) | defined(PSEUDO_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)
{
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;
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);
}
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.
*/
#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
transfersize = 0;
if (!cmd->device->borken &&
!(hostdata->flags & FLAG_NO_PSEUDO_DMA))
transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
if (transfersize) {
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
cmd->SCp.this_residual -= transfersize - len;
} else
#endif /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
{
/* Break up transfer into 3 ms chunks,
* presuming 6 accesses per handshake.
*/
transfersize = min((unsigned long)cmd->SCp.this_residual,
hostdata->accesses_per_ms / 2);
len = transfersize;
NCR5380_transfer_pio(instance, &phase, &len,
(unsigned char **)&cmd->SCp.ptr);
cmd->SCp.this_residual -= transfersize - len;
}
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);
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);
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:
case EXTENDED_MODIFY_DATA_POINTER:
case EXTENDED_EXTENDED_IDENTIFY:
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) {
shost_printk(KERN_ERR, instance, "rejecting message ");
spi_print_msg(extended_msg);
printk("\n");
} else if (tmp != EXTENDED_MESSAGE)
scmd_printk(KERN_INFO, cmd,
"rejecting unknown message %02x\n",
tmp);
else
scmd_printk(KERN_INFO, cmd,
"rejecting unknown extended message code %02x, length %d\n",
extended_msg[1], extended_msg[0]);
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);
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(instance, 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, phase;
int len;
unsigned char msg[3];
unsigned char *data;
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(instance,
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(instance,
STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
do_abort(instance);
return;
}
len = 1;
data = msg;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (len) {
do_abort(instance);
return;
}
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;
}
/* 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, tag %d\n",
scmd_id(tmp), tmp->device->lun, tmp->tag);
}
/*
* 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.
*
* Returns : pointer to the scsi_cmnd structure for which the I_T_L
* nexus has been reestablished, on failure NULL is returned.
*/
#ifdef REAL_DMA
static void NCR5380_dma_complete(NCR5380_instance * instance) {
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int transferred;
/*
* XXX this might not be right.
*
* Wait for final byte to transfer, ie wait for ACK to go false.
*
* We should use the Last Byte Sent bit, unfortunately this is
* not available on the 5380/5381 (only the various CMOS chips)
*
* FIXME: timeout, and need to handle long timeout/irq case
*/
NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/*
* The only places we should see a phase mismatch and have to send
* data from the same set of pointers will be the data transfer
* phases. So, residual, requested length are only important here.
*/
if (!(hostdata->connected->SCp.phase & SR_CD)) {
transferred = instance->dmalen - NCR5380_dma_residual();
hostdata->connected->SCp.this_residual -= transferred;
hostdata->connected->SCp.ptr += transferred;
}
}
#endif /* def REAL_DMA */
/**
* 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;
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
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);
spin_unlock_irqrestore(&hostdata->lock, flags);
return result;
}
/**
* NCR5380_bus_reset - reset the SCSI bus
* @cmd: SCSI command undergoing EH
*
* Returns SUCCESS
*/
static int NCR5380_bus_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);
cmd->scsi_done(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;
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
queue_work(hostdata->work_q, &hostdata->main_task);
spin_unlock_irqrestore(&hostdata->lock, flags);
return SUCCESS;
}
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