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Release 4.11 drivers/scsi/NCR5380.c

Directory: drivers/scsi
/*
 * 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;
}


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Linus Torvalds (pre-git)8769.05%114.29%


Finn Thain2015.87%342.86%


Boaz Harrosh118.73%114.29%


Geert Uytterhoeven75.56%114.29%


Jens Axboe10.79%114.29%


Total126100.00%7100.00%



/**
 * 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;
}


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Alan Cox5534.81%114.29%


Andrew Morton21.27%114.29%


Total158100.00%7100.00%



#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");
}


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Finn Thain2710.07%250.00%


Total268100.00%4100.00%



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);
	}
}

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Linus Torvalds (pre-git)9083.33%133.33%


Finn Thain1816.67%266.67%


Total108100.00%3100.00%



#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;
}


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Total28100.00%1100.00%



/**
 * 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;
}


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Finn Thain25665.31%1578.95%


Linus Torvalds (pre-git)12632.14%210.53%


Alan Cox92.30%15.26%


Dave Jones10.26%15.26%


Total392100.00%19100.00%



/**
 * 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;
}


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Linus Torvalds (pre-git)8149.69%222.22%


Finn Thain5936.20%444.44%


James Bottomley127.36%111.11%


Alan Cox116.75%222.22%


Total163100.00%9100.00%



/**
 * 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);
}


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James Bottomley2158.33%116.67%


Finn Thain1233.33%350.00%


Linus Torvalds (pre-git)25.56%116.67%


Dave Jones12.78%116.67%


Total36100.00%6100.00%



/**
 * 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);
}


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/**
 * 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;
}


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Linus Torvalds (pre-git)11352.80%318.75%


Finn Thain9242.99%1062.50%


Alan Cox83.74%212.50%


Dave Jones10.47%16.25%


Total214100.00%16100.00%






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);
	}
}


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/**
 * 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;
}


Contributors
PersonTokensPropCommitsCommitProp
Finn Thain19789.14%753.85%


Linus Torvalds (pre-git)188.14%323.08%


Alan Cox41.81%17.69%


James Bottomley10.45%17.69%


David Howells10.45%17.69%


Total221100.00%13100.00%






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);
}


Contributors
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Finn Thain8797.75%480.00%


Linus Torvalds (pre-git)22.25%120.00%


Total89100.00%5100.00%



/**
 * 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);
}


Contributors
PersonTokensPropCommitsCommitProp
Finn Thain14171.21%1359.09%


Linus Torvalds (pre-git)5226.26%522.73%


Hannes Reinecke21.01%14.55%


Dave Jones10.51%14.55%


Alan Cox10.51%14.55%


James Bottomley10.51%14.55%


Total198100.00%22100.00%



/*
 * 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;
			}
		}
	}
}


Contributors
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Finn Thain399100.00%3100.00%


Total399100.00%3100.00%



/**
 * 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) ||