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-rw-r--r--drivers/scsi/NCR5380.c2411
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diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
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+++ b/drivers/scsi/NCR5380.c
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NCR 5380 generic driver routines. These should make it *trivial*
+ * to implement 5380 SCSI drivers under Linux with a non-trantor
+ * architecture.
+ *
+ * Note that these routines also work with NR53c400 family chips.
+ *
+ * Copyright 1993, Drew Eckhardt
+ * Visionary Computing
+ * (Unix and Linux consulting and custom programming)
+ * drew@colorado.edu
+ * +1 (303) 666-5836
+ *
+ * For more information, please consult
+ *
+ * NCR 5380 Family
+ * SCSI Protocol Controller
+ * Databook
+ *
+ * NCR Microelectronics
+ * 1635 Aeroplaza Drive
+ * Colorado Springs, CO 80916
+ * 1+ (719) 578-3400
+ * 1+ (800) 334-5454
+ */
+
+/*
+ * With contributions from Ray Van Tassle, Ingmar Baumgart,
+ * Ronald van Cuijlenborg, Alan Cox and others.
+ */
+
+/* Ported to Atari by Roman Hodek and others. */
+
+/* Adapted for the Sun 3 by Sam Creasey. */
+
+/*
+ * Design
+ *
+ * This is a generic 5380 driver. To use it on a different platform,
+ * one simply writes appropriate system specific macros (ie, data
+ * transfer - some PC's will use the I/O bus, 68K's must use
+ * memory mapped) and drops this file in their 'C' wrapper.
+ *
+ * As far as command queueing, two queues are maintained for
+ * each 5380 in the system - commands that haven't been issued yet,
+ * and commands that are currently executing. This means that an
+ * unlimited number of commands may be queued, letting
+ * more commands propagate from the higher driver levels giving higher
+ * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
+ * allowing multiple commands to propagate all the way to a SCSI-II device
+ * while a command is already executing.
+ *
+ *
+ * Issues specific to the NCR5380 :
+ *
+ * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
+ * piece of hardware that requires you to sit in a loop polling for
+ * the REQ signal as long as you are connected. Some devices are
+ * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
+ * while doing long seek operations. [...] These
+ * broken devices are the exception rather than the rule and I'd rather
+ * spend my time optimizing for the normal case.
+ *
+ * Architecture :
+ *
+ * At the heart of the design is a coroutine, NCR5380_main,
+ * which is started from a workqueue for each NCR5380 host in the
+ * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
+ * removing the commands from the issue queue and calling
+ * NCR5380_select() if a nexus is not established.
+ *
+ * Once a nexus is established, the NCR5380_information_transfer()
+ * phase goes through the various phases as instructed by the target.
+ * if the target goes into MSG IN and sends a DISCONNECT message,
+ * the command structure is placed into the per instance disconnected
+ * queue, and NCR5380_main tries to find more work. If the target is
+ * idle for too long, the system will try to sleep.
+ *
+ * If a command has disconnected, eventually an interrupt will trigger,
+ * calling NCR5380_intr() which will in turn call NCR5380_reselect
+ * to reestablish a nexus. This will run main if necessary.
+ *
+ * On command termination, the done function will be called as
+ * appropriate.
+ *
+ * The command data pointer is 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 unsigned int disconnect_mask = ~0;
+module_param(disconnect_mask, int, 0444);
+
+static int do_abort(struct Scsi_Host *, unsigned int);
+static void do_reset(struct Scsi_Host *);
+static void bus_reset_cleanup(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)
+{
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
+
+ if (scsi_bufflen(cmd)) {
+ ncmd->buffer = scsi_sglist(cmd);
+ ncmd->ptr = sg_virt(ncmd->buffer);
+ ncmd->this_residual = ncmd->buffer->length;
+ } else {
+ ncmd->buffer = NULL;
+ ncmd->ptr = NULL;
+ ncmd->this_residual = 0;
+ }
+
+ ncmd->status = 0;
+ ncmd->message = 0;
+}
+
+static inline void advance_sg_buffer(struct NCR5380_cmd *ncmd)
+{
+ struct scatterlist *s = ncmd->buffer;
+
+ if (!ncmd->this_residual && s && !sg_is_last(s)) {
+ ncmd->buffer = sg_next(s);
+ ncmd->ptr = sg_virt(ncmd->buffer);
+ ncmd->this_residual = ncmd->buffer->length;
+ }
+}
+
+static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
+{
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
+ int resid = ncmd->this_residual;
+ struct scatterlist *s = ncmd->buffer;
+
+ if (s)
+ while (!sg_is_last(s)) {
+ s = sg_next(s);
+ resid += s->length;
+ }
+ scsi_set_resid(cmd, resid);
+}
+
+/**
+ * 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, 0 if sleeping is not allowed
+ *
+ * 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 (!wait)
+ return -ETIMEDOUT;
+
+ /* Repeatedly sleep for 1 ms until deadline */
+ while (time_is_after_jiffies(deadline)) {
+ schedule_timeout_uninterruptible(1);
+ if ((NCR5380_read(reg1) & bit1) == val1)
+ return 0;
+ if ((NCR5380_read(reg2) & bit2) == val2)
+ return 0;
+ }
+
+ return -ETIMEDOUT;
+}
+
+#if NDEBUG
+static struct {
+ unsigned char mask;
+ const char *name;
+} signals[] = {
+ {SR_DBP, "PARITY"},
+ {SR_RST, "RST"},
+ {SR_BSY, "BSY"},
+ {SR_REQ, "REQ"},
+ {SR_MSG, "MSG"},
+ {SR_CD, "CD"},
+ {SR_IO, "IO"},
+ {SR_SEL, "SEL"},
+ {0, NULL}
+},
+basrs[] = {
+ {BASR_END_DMA_TRANSFER, "END OF DMA"},
+ {BASR_DRQ, "DRQ"},
+ {BASR_PARITY_ERROR, "PARITY ERROR"},
+ {BASR_IRQ, "IRQ"},
+ {BASR_PHASE_MATCH, "PHASE MATCH"},
+ {BASR_BUSY_ERROR, "BUSY ERROR"},
+ {BASR_ATN, "ATN"},
+ {BASR_ACK, "ACK"},
+ {0, NULL}
+},
+icrs[] = {
+ {ICR_ASSERT_RST, "ASSERT RST"},
+ {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
+ {ICR_ARBITRATION_LOST, "LOST ARB."},
+ {ICR_ASSERT_ACK, "ASSERT ACK"},
+ {ICR_ASSERT_BSY, "ASSERT BSY"},
+ {ICR_ASSERT_SEL, "ASSERT SEL"},
+ {ICR_ASSERT_ATN, "ASSERT ATN"},
+ {ICR_ASSERT_DATA, "ASSERT DATA"},
+ {0, NULL}
+},
+mrs[] = {
+ {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
+ {MR_TARGET, "TARGET"},
+ {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
+ {MR_ENABLE_PAR_INTR, "PARITY INTR"},
+ {MR_ENABLE_EOP_INTR, "EOP INTR"},
+ {MR_MONITOR_BSY, "MONITOR BSY"},
+ {MR_DMA_MODE, "DMA MODE"},
+ {MR_ARBITRATE, "ARBITRATE"},
+ {0, NULL}
+};
+
+/**
+ * NCR5380_print - print scsi bus signals
+ * @instance: adapter state to dump
+ *
+ * Print the SCSI bus signals for debugging purposes
+ */
+
+static void NCR5380_print(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char status, basr, mr, icr, i;
+
+ status = NCR5380_read(STATUS_REG);
+ mr = NCR5380_read(MODE_REG);
+ icr = NCR5380_read(INITIATOR_COMMAND_REG);
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+
+ printk(KERN_DEBUG "SR = 0x%02x : ", status);
+ for (i = 0; signals[i].mask; ++i)
+ if (status & signals[i].mask)
+ printk(KERN_CONT "%s, ", signals[i].name);
+ printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
+ for (i = 0; basrs[i].mask; ++i)
+ if (basr & basrs[i].mask)
+ printk(KERN_CONT "%s, ", basrs[i].name);
+ printk(KERN_CONT "\nICR = 0x%02x : ", icr);
+ for (i = 0; icrs[i].mask; ++i)
+ if (icr & icrs[i].mask)
+ printk(KERN_CONT "%s, ", icrs[i].name);
+ printk(KERN_CONT "\nMR = 0x%02x : ", mr);
+ for (i = 0; mrs[i].mask; ++i)
+ if (mr & mrs[i].mask)
+ printk(KERN_CONT "%s, ", mrs[i].name);
+ printk(KERN_CONT "\n");
+}
+
+static struct {
+ unsigned char value;
+ const char *name;
+} phases[] = {
+ {PHASE_DATAOUT, "DATAOUT"},
+ {PHASE_DATAIN, "DATAIN"},
+ {PHASE_CMDOUT, "CMDOUT"},
+ {PHASE_STATIN, "STATIN"},
+ {PHASE_MSGOUT, "MSGOUT"},
+ {PHASE_MSGIN, "MSGIN"},
+ {PHASE_UNKNOWN, "UNKNOWN"}
+};
+
+/**
+ * NCR5380_print_phase - show SCSI phase
+ * @instance: adapter to dump
+ *
+ * Print the current SCSI phase for debugging purposes
+ */
+
+static void NCR5380_print_phase(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char status;
+ int i;
+
+ status = NCR5380_read(STATUS_REG);
+ if (!(status & SR_REQ))
+ shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
+ else {
+ for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
+ (phases[i].value != (status & PHASE_MASK)); ++i)
+ ;
+ shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
+ }
+}
+#endif
+
+/**
+ * NCR5380_info - report driver and host information
+ * @instance: relevant scsi host instance
+ *
+ * For use as the host template info() handler.
+ */
+
+static const char *NCR5380_info(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ return hostdata->info;
+}
+
+/**
+ * NCR5380_init - initialise an NCR5380
+ * @instance: adapter to configure
+ * @flags: control flags
+ *
+ * Initializes *instance and corresponding 5380 chip,
+ * with flags OR'd into the initial flags value.
+ *
+ * Notes : I assume that the host, hostno, and id bits have been
+ * set correctly. I don't care about the irq and other fields.
+ *
+ * Returns 0 for success
+ */
+
+static int NCR5380_init(struct Scsi_Host *instance, int flags)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int i;
+ unsigned long deadline;
+ unsigned long accesses_per_ms;
+
+ instance->max_lun = 7;
+
+ hostdata->host = instance;
+ hostdata->id_mask = 1 << instance->this_id;
+ hostdata->id_higher_mask = 0;
+ for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
+ if (i > hostdata->id_mask)
+ hostdata->id_higher_mask |= i;
+ for (i = 0; i < 8; ++i)
+ hostdata->busy[i] = 0;
+ hostdata->dma_len = 0;
+
+ spin_lock_init(&hostdata->lock);
+ hostdata->connected = NULL;
+ hostdata->sensing = NULL;
+ INIT_LIST_HEAD(&hostdata->autosense);
+ INIT_LIST_HEAD(&hostdata->unissued);
+ INIT_LIST_HEAD(&hostdata->disconnected);
+
+ hostdata->flags = flags;
+
+ INIT_WORK(&hostdata->main_task, NCR5380_main);
+ hostdata->work_q = alloc_workqueue("ncr5380_%d",
+ WQ_UNBOUND | WQ_MEM_RECLAIM,
+ 1, instance->host_no);
+ if (!hostdata->work_q)
+ return -ENOMEM;
+
+ snprintf(hostdata->info, sizeof(hostdata->info),
+ "%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
+ instance->hostt->name, instance->irq, hostdata->io_port,
+ hostdata->base, instance->can_queue, instance->cmd_per_lun,
+ instance->sg_tablesize, instance->this_id,
+ hostdata->flags & FLAG_DMA_FIXUP ? "DMA_FIXUP " : "",
+ hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
+ hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+
+ /* Calibrate register polling loop */
+ i = 0;
+ deadline = jiffies + 1;
+ do {
+ cpu_relax();
+ } while (time_is_after_jiffies(deadline));
+ deadline += msecs_to_jiffies(256);
+ do {
+ NCR5380_read(STATUS_REG);
+ ++i;
+ cpu_relax();
+ } while (time_is_after_jiffies(deadline));
+ accesses_per_ms = i / 256;
+ hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
+
+ return 0;
+}
+
+/**
+ * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
+ * @instance: adapter to check
+ *
+ * If the system crashed, it may have crashed with a connected target and
+ * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
+ * currently established nexus, which we know nothing about. Failing that
+ * do a bus reset.
+ *
+ * Note that a bus reset will cause the chip to assert IRQ.
+ *
+ * Returns 0 if successful, otherwise -ENXIO.
+ */
+
+static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int pass;
+
+ for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
+ switch (pass) {
+ case 1:
+ case 3:
+ case 5:
+ shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
+ NCR5380_poll_politely(hostdata,
+ STATUS_REG, SR_BSY, 0, 5 * HZ);
+ break;
+ case 2:
+ shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
+ do_abort(instance, 1);
+ 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 (get_status_byte(cmd) != SAM_STAT_GOOD) {
+ scsi_eh_restore_cmnd(cmd, &hostdata->ses);
+ } else {
+ scsi_eh_restore_cmnd(cmd, &hostdata->ses);
+ set_status_byte(cmd, SAM_STAT_CHECK_CONDITION);
+ }
+ hostdata->sensing = NULL;
+ }
+
+ 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 = NCR5380_to_ncmd(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);
+ scsi_done(cmd);
+ return 0;
+ }
+#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
+
+ cmd->result = 0;
+
+ spin_lock_irqsave(&hostdata->lock, flags);
+
+ if (!NCR5380_acquire_dma_irq(instance)) {
+ spin_unlock_irqrestore(&hostdata->lock, flags);
+
+ return SCSI_MLQUEUE_HOST_BUSY;
+ }
+
+ /*
+ * Insert the cmd into the issue queue. Note that REQUEST SENSE
+ * commands are added to the head of the queue since any command will
+ * clear the contingent allegiance condition that exists and the
+ * sense data is only guaranteed to be valid while the condition exists.
+ */
+
+ if (cmd->cmnd[0] == REQUEST_SENSE)
+ list_add(&ncmd->list, &hostdata->unissued);
+ else
+ list_add_tail(&ncmd->list, &hostdata->unissued);
+
+ spin_unlock_irqrestore(&hostdata->lock, flags);
+
+ dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
+ cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
+
+ /* Kick off command processing */
+ queue_work(hostdata->work_q, &hostdata->main_task);
+ return 0;
+}
+
+static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ /* Caller does the locking needed to set & test these data atomically */
+ if (list_empty(&hostdata->disconnected) &&
+ list_empty(&hostdata->unissued) &&
+ list_empty(&hostdata->autosense) &&
+ !hostdata->connected &&
+ !hostdata->selecting) {
+ NCR5380_release_dma_irq(instance);
+ }
+}
+
+/**
+ * dequeue_next_cmd - dequeue a command for processing
+ * @instance: the scsi host instance
+ *
+ * Priority is given to commands on the autosense queue. These commands
+ * need autosense because of a CHECK CONDITION result.
+ *
+ * Returns a command pointer if a command is found for a target that is
+ * not already busy. Otherwise returns NULL.
+ */
+
+static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ struct NCR5380_cmd *ncmd;
+ struct scsi_cmnd *cmd;
+
+ if (hostdata->sensing || list_empty(&hostdata->autosense)) {
+ list_for_each_entry(ncmd, &hostdata->unissued, list) {
+ cmd = NCR5380_to_scmd(ncmd);
+ dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
+ cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
+
+ if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
+ list_del(&ncmd->list);
+ dsprintk(NDEBUG_QUEUES, instance,
+ "dequeue: removed %p from issue queue\n", cmd);
+ return cmd;
+ }
+ }
+ } else {
+ /* Autosense processing begins here */
+ ncmd = list_first_entry(&hostdata->autosense,
+ struct NCR5380_cmd, list);
+ list_del(&ncmd->list);
+ cmd = NCR5380_to_scmd(ncmd);
+ dsprintk(NDEBUG_QUEUES, instance,
+ "dequeue: removed %p from autosense queue\n", cmd);
+ scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
+ hostdata->sensing = cmd;
+ return cmd;
+ }
+ return NULL;
+}
+
+static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(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 && !hostdata->dma_len) {
+ dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
+ NCR5380_information_transfer(instance);
+ done = 0;
+ }
+ if (!hostdata->connected) {
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ maybe_release_dma_irq(instance);
+ }
+ spin_unlock_irq(&hostdata->lock);
+ if (!done)
+ cond_resched();
+ } while (!done);
+}
+
+/*
+ * NCR5380_dma_complete - finish DMA transfer
+ * @instance: the scsi host instance
+ *
+ * Called by the interrupt handler when DMA finishes or a phase
+ * mismatch occurs (which would end the DMA transfer).
+ */
+
+static void NCR5380_dma_complete(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(hostdata->connected);
+ int transferred;
+ unsigned char **data;
+ int *count;
+ int saved_data = 0, overrun = 0;
+ unsigned char p;
+
+ if (hostdata->read_overruns) {
+ p = ncmd->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(hostdata->connected->sc_data_direction)) {
+ 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 **)&ncmd->ptr;
+ count = &ncmd->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, 0);
+ *count -= toPIO - cnt;
+ }
+ }
+ }
+}
+
+/**
+ * NCR5380_intr - generic NCR5380 irq handler
+ * @irq: interrupt number
+ * @dev_id: device info
+ *
+ * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
+ * from the disconnected queue, and restarting NCR5380_main()
+ * as required.
+ *
+ * The chip can assert IRQ in any of six different conditions. The IRQ flag
+ * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
+ * Three of these six conditions are latched in the Bus and Status Register:
+ * - End of DMA (cleared by ending DMA Mode)
+ * - Parity error (cleared by reading RPIR)
+ * - Loss of BSY (cleared by reading RPIR)
+ * Two conditions have flag bits that are not latched:
+ * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
+ * - Bus reset (non-maskable)
+ * The remaining condition has no flag bit at all:
+ * - Selection/reselection
+ *
+ * Hence, establishing the cause(s) of any interrupt is partly guesswork.
+ * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
+ * claimed that "the design of the [DP8490] interrupt logic ensures
+ * interrupts will not be lost (they can be on the DP5380)."
+ * The L5380/53C80 datasheet from LOGIC Devices has more details.
+ *
+ * Checking for bus reset by reading RST is futile because of interrupt
+ * latency, but a bus reset will reset chip logic. Checking for parity error
+ * is unnecessary because that interrupt is never enabled. A Loss of BSY
+ * condition will clear DMA Mode. We can tell when this occurs because the
+ * the Busy Monitor interrupt is enabled together with DMA Mode.
+ */
+
+static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
+{
+ struct Scsi_Host *instance = dev_id;
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int handled = 0;
+ unsigned char basr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&hostdata->lock, flags);
+
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+ if (basr & BASR_IRQ) {
+ unsigned char mr = NCR5380_read(MODE_REG);
+ unsigned char sr = NCR5380_read(STATUS_REG);
+
+ dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
+ irq, basr, sr, mr);
+
+ if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
+ /* Probably End of DMA, Phase Mismatch or Loss of BSY.
+ * We ack IRQ after clearing Mode Register. Workarounds
+ * for End of DMA errata need to happen in DMA Mode.
+ */
+
+ dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
+
+ if (hostdata->connected) {
+ NCR5380_dma_complete(instance);
+ queue_work(hostdata->work_q, &hostdata->main_task);
+ } else {
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ }
+ } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
+ (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
+ /* Probably reselected */
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+
+ dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
+
+ if (!hostdata->connected) {
+ NCR5380_reselect(instance);
+ queue_work(hostdata->work_q, &hostdata->main_task);
+ }
+ if (!hostdata->connected)
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ } else {
+ /* Probably Bus Reset */
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+
+ if (sr & SR_RST) {
+ /* Certainly Bus Reset */
+ shost_printk(KERN_WARNING, instance,
+ "bus reset interrupt\n");
+ bus_reset_cleanup(instance);
+ } else {
+ dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
+ }
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ }
+ handled = 1;
+ } else {
+ dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ }
+
+ spin_unlock_irqrestore(&hostdata->lock, flags);
+
+ return IRQ_RETVAL(handled);
+}
+
+/**
+ * NCR5380_select - attempt arbitration and selection for a given command
+ * @instance: the Scsi_Host instance
+ * @cmd: the scsi_cmnd to execute
+ *
+ * This routine establishes an I_T_L nexus for a SCSI command. This involves
+ * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
+ *
+ * Returns true if the operation should be retried.
+ * Returns false if it should not be retried.
+ *
+ * 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 : the I_T_L nexus will be established, and
+ * hostdata->connected will be set to cmd.
+ * SELECT interrupt will be disabled.
+ *
+ * If failed (no target) : scsi_done() will be called, and the
+ * cmd->result host byte set to DID_BAD_TARGET.
+ */
+
+static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
+ __releases(&hostdata->lock) __acquires(&hostdata->lock)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char tmp[3], phase;
+ unsigned char *data;
+ int len;
+ int err;
+ bool ret = true;
+ bool can_disconnect = instance->irq != NO_IRQ &&
+ cmd->cmnd[0] != REQUEST_SENSE &&
+ (disconnect_mask & BIT(scmd_id(cmd)));
+
+ 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 false
+ * so that the caller will forget about 'cmd'. (During information
+ * transfer phases, EH may change 'connected' to NULL.)
+ */
+ hostdata->selecting = cmd;
+
+ /*
+ * Set the phase bits to 0, otherwise the NCR5380 won't drive the
+ * data bus during SELECTION.
+ */
+
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+
+ /*
+ * Start arbitration.
+ */
+
+ NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
+ NCR5380_write(MODE_REG, MR_ARBITRATE);
+
+ /* The chip now waits for BUS FREE phase. Then after the 800 ns
+ * Bus Free Delay, arbitration will begin.
+ */
+
+ spin_unlock_irq(&hostdata->lock);
+ err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
+ INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
+ ICR_ARBITRATION_PROGRESS, HZ);
+ spin_lock_irq(&hostdata->lock);
+ if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
+ /* Reselection interrupt */
+ goto out;
+ }
+ if (!hostdata->selecting) {
+ /* Command was aborted */
+ NCR5380_write(MODE_REG, MR_BASE);
+ return false;
+ }
+ 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);
+ return false;
+ }
+
+ dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
+
+ /*
+ * Now that we have won arbitration, start Selection process, asserting
+ * the host and target ID's on the SCSI bus.
+ */
+
+ NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
+
+ /*
+ * Raise ATN while SEL is true before BSY goes false from arbitration,
+ * since this is the only way to guarantee that we'll get a MESSAGE OUT
+ * phase immediately after selection.
+ */
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
+ NCR5380_write(MODE_REG, MR_BASE);
+
+ /*
+ * Reselect interrupts must be turned off prior to the dropping of BSY,
+ * otherwise we will trigger an interrupt.
+ */
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+
+ spin_unlock_irq(&hostdata->lock);
+
+ /*
+ * The initiator shall then wait at least two deskew delays and release
+ * the BSY signal.
+ */
+ udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
+
+ /* Reset BSY */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
+ ICR_ASSERT_ATN | ICR_ASSERT_SEL);
+
+ /*
+ * Something weird happens when we cease to drive BSY - looks
+ * like the board/chip is letting us do another read before the
+ * appropriate propagation delay has expired, and we're confusing
+ * a BSY signal from ourselves as the target's response to SELECTION.
+ *
+ * A small delay (the 'C++' frontend breaks the pipeline with an
+ * unnecessary jump, making it work on my 386-33/Trantor T128, the
+ * tighter 'C' code breaks and requires this) solves the problem -
+ * the 1 us delay is arbitrary, and only used because this delay will
+ * be the same on other platforms and since it works here, it should
+ * work there.
+ *
+ * wingel suggests that this could be due to failing to wait
+ * one deskew delay.
+ */
+
+ udelay(1);
+
+ dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
+
+ /*
+ * The SCSI specification calls for a 250 ms timeout for the actual
+ * selection.
+ */
+
+ err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
+ msecs_to_jiffies(250));
+
+ if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
+ spin_lock_irq(&hostdata->lock);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_reselect(instance);
+ 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);
+
+ /* Can't touch cmd if it has been reclaimed by the scsi ML */
+ if (!hostdata->selecting)
+ return false;
+
+ cmd->result = DID_BAD_TARGET << 16;
+ complete_cmd(instance, cmd);
+ dsprintk(NDEBUG_SELECTION, instance,
+ "target did not respond within 250ms\n");
+ ret = false;
+ goto out;
+ }
+
+ /*
+ * No less than two deskew delays after the initiator detects the
+ * BSY signal is true, it shall release the SEL signal and may
+ * change the DATA BUS. -wingel
+ */
+
+ udelay(1);
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+
+ /*
+ * Since we followed the SCSI spec, and raised ATN while SEL
+ * was true but before BSY was false during selection, the information
+ * transfer phase should be a MESSAGE OUT phase so that we can send the
+ * IDENTIFY message.
+ */
+
+ /* Wait for start of REQ/ACK handshake */
+
+ err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
+ spin_lock_irq(&hostdata->lock);
+ if (err < 0) {
+ shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ goto out;
+ }
+ if (!hostdata->selecting) {
+ do_abort(instance, 0);
+ return false;
+ }
+
+ dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
+ scmd_id(cmd));
+ tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
+
+ len = 1;
+ data = tmp;
+ phase = PHASE_MSGOUT;
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
+ if (len) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ cmd->result = DID_ERROR << 16;
+ complete_cmd(instance, cmd);
+ dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
+ ret = false;
+ goto out;
+ }
+
+ dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
+
+ hostdata->connected = cmd;
+ hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
+
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+
+ initialize_SCp(cmd);
+
+ ret = false;
+
+out:
+ if (!hostdata->selecting)
+ return false;
+ hostdata->selecting = NULL;
+ return ret;
+}
+
+/*
+ * 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,
+ * can_sleep - 1 or 0 when sleeping is permitted or not, respectively.
+ *
+ * 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 int can_sleep)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char p = *phase, tmp;
+ int c = *count;
+ unsigned char *d = *data;
+
+ /*
+ * The NCR5380 chip will only drive the SCSI bus when the
+ * phase specified in the appropriate bits of the TARGET COMMAND
+ * REGISTER match the STATUS REGISTER
+ */
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
+
+ do {
+ /*
+ * Wait for assertion of REQ, after which the phase bits will be
+ * valid
+ */
+
+ if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
+ HZ * can_sleep) < 0)
+ break;
+
+ dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
+
+ /* Check for phase mismatch */
+ if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
+ dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
+ NCR5380_dprint_phase(NDEBUG_PIO, instance);
+ break;
+ }
+
+ /* Do actual transfer from SCSI bus to / from memory */
+ if (!(p & SR_IO))
+ NCR5380_write(OUTPUT_DATA_REG, *d);
+ else
+ *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
+
+ ++d;
+
+ /*
+ * The SCSI standard suggests that in MSGOUT phase, the initiator
+ * should drop ATN on the last byte of the message phase
+ * after REQ has been asserted for the handshake but before
+ * the initiator raises ACK.
+ */
+
+ if (!(p & SR_IO)) {
+ if (!((p & SR_MSG) && c > 1)) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ACK);
+ } else {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN);
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
+ }
+ } else {
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
+ }
+
+ if (NCR5380_poll_politely(hostdata,
+ STATUS_REG, SR_REQ, 0, 5 * HZ * can_sleep) < 0)
+ break;
+
+ dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
+
+/*
+ * We have several special cases to consider during REQ/ACK handshaking :
+ * 1. We were in MSGOUT phase, and we are on the last byte of the
+ * message. ATN must be dropped as ACK is dropped.
+ *
+ * 2. We are in a MSGIN phase, and we are on the last byte of the
+ * message. We must exit with ACK asserted, so that the calling
+ * code may raise ATN before dropping ACK to reject the message.
+ *
+ * 3. ACK and ATN are clear and the target may proceed as normal.
+ */
+ if (!(p == PHASE_MSGIN && c == 1)) {
+ if (p == PHASE_MSGOUT && c > 1)
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+ else
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ }
+ } while (--c);
+
+ dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
+
+ *count = c;
+ *data = d;
+ tmp = NCR5380_read(STATUS_REG);
+ /* The phase read from the bus is valid if either REQ is (already)
+ * asserted or if ACK hasn't been released yet. The latter applies if
+ * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
+ */
+ if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
+ *phase = tmp & PHASE_MASK;
+ else
+ *phase = PHASE_UNKNOWN;
+
+ if (!c || (*phase == p))
+ return 0;
+ else
+ return -1;
+}
+
+/**
+ * do_reset - issue a reset command
+ * @instance: adapter to reset
+ *
+ * Issue a reset sequence to the NCR5380 and try and get the bus
+ * back into sane shape.
+ *
+ * This clears the reset interrupt flag because there may be no handler for
+ * it. When the driver is initialized, the NCR5380_intr() handler has not yet
+ * been installed. And when in EH we may have released the ST DMA interrupt.
+ */
+
+static void do_reset(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ NCR5380_write(TARGET_COMMAND_REG,
+ PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
+ udelay(50);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ local_irq_restore(flags);
+}
+
+/**
+ * do_abort - abort the currently established nexus by going to
+ * MESSAGE OUT phase and sending an ABORT message.
+ * @instance: relevant scsi host instance
+ * @can_sleep: 1 or 0 when sleeping is permitted or not, respectively
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+
+static int do_abort(struct Scsi_Host *instance, unsigned int can_sleep)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char *msgptr, phase, tmp;
+ int len;
+ int rc;
+
+ /* Request message out phase */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+
+ /*
+ * Wait for the target to indicate a valid phase by asserting
+ * REQ. Once this happens, we'll have either a MSGOUT phase
+ * and can immediately send the ABORT message, or we'll have some
+ * other phase and will have to source/sink data.
+ *
+ * We really don't care what value was on the bus or what value
+ * the target sees, so we just handshake.
+ */
+
+ rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
+ 10 * HZ * can_sleep);
+ if (rc < 0)
+ goto out;
+
+ tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
+
+ if (tmp != PHASE_MSGOUT) {
+ NCR5380_write(INITIATOR_COMMAND_REG,
+ ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
+ rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0,
+ 3 * HZ * can_sleep);
+ if (rc < 0)
+ goto out;
+ 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, can_sleep);
+ if (len)
+ rc = -ENXIO;
+
+ /*
+ * If we got here, and the command completed successfully,
+ * we're about to go into bus free state.
+ */
+
+out:
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return rc;
+}
+
+/*
+ * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
+ * unsigned char *phase, int *count, unsigned char **data)
+ *
+ * Purpose : transfers data in given phase using either real
+ * or pseudo DMA.
+ *
+ * Inputs : instance - instance of driver, *phase - pointer to
+ * what phase is expected, *count - pointer to number of
+ * bytes to transfer, **data - pointer to data pointer.
+ *
+ * Returns : -1 when different phase is entered without transferring
+ * maximum number of bytes, 0 if all bytes or transferred or exit
+ * is in same phase.
+ *
+ * Also, *phase, *count, *data are modified in place.
+ */
+
+
+static int NCR5380_transfer_dma(struct Scsi_Host *instance,
+ unsigned char *phase, int *count,
+ unsigned char **data)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int c = *count;
+ unsigned char p = *phase;
+ unsigned char *d = *data;
+ unsigned char tmp;
+ int result = 0;
+
+ if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
+ *phase = tmp;
+ return -1;
+ }
+
+ NCR5380_to_ncmd(hostdata->connected)->phase = p;
+
+ if (p & SR_IO) {
+ if (hostdata->read_overruns)
+ c -= hostdata->read_overruns;
+ else if (hostdata->flags & FLAG_DMA_FIXUP)
+ --c;
+ }
+
+ dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
+ (p & SR_IO) ? "receive" : "send", c, d);
+
+#ifdef CONFIG_SUN3
+ /* send start chain */
+ sun3scsi_dma_start(c, *data);
+#endif
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
+ NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
+ MR_ENABLE_EOP_INTR);
+
+ if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
+ /* On the Medusa, it is a must to initialize the DMA before
+ * starting the NCR. This is also the cleaner way for the TT.
+ */
+ if (p & SR_IO)
+ result = NCR5380_dma_recv_setup(hostdata, d, c);
+ else
+ result = NCR5380_dma_send_setup(hostdata, d, c);
+ }
+
+ /*
+ * On the PAS16 at least I/O recovery delays are not needed here.
+ * Everyone else seems to want them.
+ */
+
+ if (p & SR_IO) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_io_delay(1);
+ NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
+ } else {
+ NCR5380_io_delay(1);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
+ NCR5380_io_delay(1);
+ NCR5380_write(START_DMA_SEND_REG, 0);
+ NCR5380_io_delay(1);
+ }
+
+#ifdef CONFIG_SUN3
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ sun3_dma_active = 1;
+#endif
+
+ if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
+ /* On the Falcon, the DMA setup must be done after the last
+ * NCR access, else the DMA setup gets trashed!
+ */
+ if (p & SR_IO)
+ result = NCR5380_dma_recv_setup(hostdata, d, c);
+ else
+ result = NCR5380_dma_send_setup(hostdata, d, c);
+ }
+
+ /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
+ if (result < 0)
+ return result;
+
+ /* For real DMA, result is the byte count. DMA interrupt is expected. */
+ if (result > 0) {
+ hostdata->dma_len = result;
+ return 0;
+ }
+
+ /* The result is zero iff pseudo DMA send/receive was completed. */
+ hostdata->dma_len = c;
+
+/*
+ * A note regarding the DMA errata workarounds for early NMOS silicon.
+ *
+ * For DMA sends, we want to wait until the last byte has been
+ * transferred out over the bus before we turn off DMA mode. Alas, there
+ * seems to be no terribly good way of doing this on a 5380 under all
+ * conditions. For non-scatter-gather operations, we can wait until REQ
+ * and ACK both go false, or until a phase mismatch occurs. Gather-sends
+ * are nastier, since the device will be expecting more data than we
+ * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
+ * could test Last Byte Sent to assure transfer (I imagine this is precisely
+ * why this signal was added to the newer chips) but on the older 538[01]
+ * this signal does not exist. The workaround for this lack is a watchdog;
+ * we bail out of the wait-loop after a modest amount of wait-time if
+ * the usual exit conditions are not met. Not a terribly clean or
+ * correct solution :-%
+ *
+ * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
+ * If the chip is in DMA receive mode, it will respond to a target's
+ * REQ by latching the SCSI data into the INPUT DATA register and asserting
+ * ACK, even if it has _already_ been notified by the DMA controller that
+ * the current DMA transfer has completed! If the NCR5380 is then taken
+ * out of DMA mode, this already-acknowledged byte is lost. This is
+ * not a problem for "one DMA transfer per READ command", because
+ * the situation will never arise... either all of the data is DMA'ed
+ * properly, or the target switches to MESSAGE IN phase to signal a
+ * disconnection (either operation bringing the DMA to a clean halt).
+ * However, in order to handle scatter-receive, we must work around the
+ * problem. The chosen fix is to DMA fewer bytes, then check for the
+ * condition before taking the NCR5380 out of DMA mode. One or two extra
+ * bytes are transferred via PIO as necessary to fill out the original
+ * request.
+ */
+
+ if (hostdata->flags & FLAG_DMA_FIXUP) {
+ if (p & SR_IO) {
+ /*
+ * The workaround was to transfer fewer bytes than we
+ * intended to with the pseudo-DMA read function, wait for
+ * the chip to latch the last byte, read it, and then disable
+ * pseudo-DMA mode.
+ *
+ * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
+ * REQ is deasserted when ACK is asserted, and not reasserted
+ * until ACK goes false. Since the NCR5380 won't lower ACK
+ * until DACK is asserted, which won't happen unless we twiddle
+ * the DMA port or we take the NCR5380 out of DMA mode, we
+ * can guarantee that we won't handshake another extra
+ * byte.
+ */
+
+ if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
+ BASR_DRQ, BASR_DRQ, 0) < 0) {
+ result = -1;
+ shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
+ }
+ if (NCR5380_poll_politely(hostdata, STATUS_REG,
+ SR_REQ, 0, 0) < 0) {
+ result = -1;
+ shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
+ }
+ d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
+ } else {
+ /*
+ * Wait for the last byte to be sent. If REQ is being asserted for
+ * the byte we're interested, we'll ACK it and it will go false.
+ */
+ if (NCR5380_poll_politely2(hostdata,
+ BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
+ BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0) < 0) {
+ result = -1;
+ shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
+ }
+ }
+ }
+
+ NCR5380_dma_complete(instance);
+ return result;
+}
+
+/*
+ * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
+ *
+ * Purpose : run through the various SCSI phases and do as the target
+ * directs us to. Operates on the currently connected command,
+ * instance->connected.
+ *
+ * Inputs : instance, instance for which we are doing commands
+ *
+ * Side effects : SCSI things happen, the disconnected queue will be
+ * modified if a command disconnects, *instance->connected will
+ * change.
+ *
+ * XXX Note : we need to watch for bus free or a reset condition here
+ * to recover from an unexpected bus free condition.
+ */
+
+static void NCR5380_information_transfer(struct Scsi_Host *instance)
+ __releases(&hostdata->lock) __acquires(&hostdata->lock)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char msgout = NOP;
+ int sink = 0;
+ int len;
+ int transfersize;
+ unsigned char *data;
+ unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
+ struct scsi_cmnd *cmd;
+
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+
+ while ((cmd = hostdata->connected)) {
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
+
+ tmp = NCR5380_read(STATUS_REG);
+ /* We only have a valid SCSI phase when REQ is asserted */
+ if (tmp & SR_REQ) {
+ phase = (tmp & PHASE_MASK);
+ if (phase != old_phase) {
+ old_phase = phase;
+ NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
+ }
+#ifdef CONFIG_SUN3
+ if (phase == PHASE_CMDOUT &&
+ sun3_dma_setup_done != cmd) {
+ int count;
+
+ advance_sg_buffer(ncmd);
+
+ count = sun3scsi_dma_xfer_len(hostdata, cmd);
+
+ if (count > 0) {
+ if (cmd->sc_data_direction == DMA_TO_DEVICE)
+ sun3scsi_dma_send_setup(hostdata,
+ ncmd->ptr, count);
+ else
+ sun3scsi_dma_recv_setup(hostdata,
+ ncmd->ptr, count);
+ sun3_dma_setup_done = cmd;
+ }
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+ }
+#endif /* CONFIG_SUN3 */
+
+ if (sink && (phase != PHASE_MSGOUT)) {
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
+ ICR_ASSERT_ACK);
+ while (NCR5380_read(STATUS_REG) & SR_REQ)
+ ;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_ATN);
+ sink = 0;
+ continue;
+ }
+
+ switch (phase) {
+ case PHASE_DATAOUT:
+#if (NDEBUG & NDEBUG_NO_DATAOUT)
+ shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
+ sink = 1;
+ do_abort(instance, 0);
+ cmd->result = DID_ERROR << 16;
+ complete_cmd(instance, cmd);
+ hostdata->connected = NULL;
+ hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
+ 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.
+ */
+
+ advance_sg_buffer(ncmd);
+ dsprintk(NDEBUG_INFORMATION, instance,
+ "this residual %d, sg ents %d\n",
+ ncmd->this_residual,
+ sg_nents(ncmd->buffer));
+
+ /*
+ * The preferred transfer method is going to be
+ * PSEUDO-DMA for systems that are strictly PIO,
+ * since we can let the hardware do the handshaking.
+ *
+ * For this to work, we need to know the transfersize
+ * ahead of time, since the pseudo-DMA code will sit
+ * in an unconditional loop.
+ */
+
+ transfersize = 0;
+ if (!cmd->device->borken)
+ transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
+
+ if (transfersize > 0) {
+ len = transfersize;
+ if (NCR5380_transfer_dma(instance, &phase,
+ &len, (unsigned char **)&ncmd->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;
+ do_reset(instance);
+ bus_reset_cleanup(instance);
+ }
+ } else {
+ /* Transfer a small chunk so that the
+ * irq mode lock is not held too long.
+ */
+ transfersize = min(ncmd->this_residual,
+ NCR5380_PIO_CHUNK_SIZE);
+ len = transfersize;
+ NCR5380_transfer_pio(instance, &phase, &len,
+ (unsigned char **)&ncmd->ptr,
+ 0);
+ ncmd->this_residual -= transfersize - len;
+ }
+#ifdef CONFIG_SUN3
+ if (sun3_dma_setup_done == cmd)
+ sun3_dma_setup_done = NULL;
+#endif
+ return;
+ case PHASE_MSGIN:
+ len = 1;
+ data = &tmp;
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
+ ncmd->message = tmp;
+
+ switch (tmp) {
+ case ABORT:
+ set_host_byte(cmd, DID_ABORT);
+ fallthrough;
+ 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;
+ hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
+
+ set_status_byte(cmd, ncmd->status);
+
+ set_resid_from_SCp(cmd);
+
+ if (cmd->cmnd[0] == REQUEST_SENSE)
+ complete_cmd(instance, cmd);
+ else {
+ if (ncmd->status == SAM_STAT_CHECK_CONDITION ||
+ ncmd->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);
+
+ 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);
+
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ return;
+ /*
+ * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
+ * operation, in violation of the SCSI spec so we can safely
+ * ignore SAVE/RESTORE pointers calls.
+ *
+ * Unfortunately, some disks violate the SCSI spec and
+ * don't issue the required SAVE_POINTERS message before
+ * disconnecting, and we have to break spec to remain
+ * compatible.
+ */
+ case SAVE_POINTERS:
+ case RESTORE_POINTERS:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ break;
+ case EXTENDED_MESSAGE:
+ /*
+ * Start the message buffer with the EXTENDED_MESSAGE
+ * byte, since spi_print_msg() wants the whole thing.
+ */
+ extended_msg[0] = EXTENDED_MESSAGE;
+ /* Accept first byte by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ spin_unlock_irq(&hostdata->lock);
+
+ dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
+
+ len = 2;
+ data = extended_msg + 1;
+ phase = PHASE_MSGIN;
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 1);
+ 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, 1);
+ dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
+ len);
+
+ switch (extended_msg[2]) {
+ case EXTENDED_SDTR:
+ case EXTENDED_WDTR:
+ tmp = 0;
+ }
+ } else if (len) {
+ shost_printk(KERN_ERR, instance, "error receiving extended message\n");
+ tmp = 0;
+ } else {
+ shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
+ extended_msg[2], extended_msg[1]);
+ tmp = 0;
+ }
+
+ spin_lock_irq(&hostdata->lock);
+ if (!hostdata->connected)
+ return;
+
+ /* Reject message */
+ fallthrough;
+ default:
+ /*
+ * If we get something weird that we aren't expecting,
+ * log it.
+ */
+ if (tmp == EXTENDED_MESSAGE)
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown extended message code %02x, length %d\n",
+ extended_msg[2], extended_msg[1]);
+ else if (tmp)
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown message code %02x\n",
+ tmp);
+
+ msgout = MESSAGE_REJECT;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+ break;
+ } /* switch (tmp) */
+ break;
+ case PHASE_MSGOUT:
+ len = 1;
+ data = &msgout;
+ hostdata->last_message = msgout;
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
+ if (msgout == ABORT) {
+ hostdata->connected = NULL;
+ hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
+ cmd->result = DID_ERROR << 16;
+ complete_cmd(instance, cmd);
+ 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, 0);
+ break;
+ case PHASE_STATIN:
+ len = 1;
+ data = &tmp;
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
+ ncmd->status = tmp;
+ break;
+ default:
+ shost_printk(KERN_ERR, instance, "unknown phase\n");
+ NCR5380_dprint(NDEBUG_ANY, instance);
+ } /* switch(phase) */
+ } else {
+ spin_unlock_irq(&hostdata->lock);
+ NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
+ spin_lock_irq(&hostdata->lock);
+ }
+ }
+}
+
+/*
+ * Function : void NCR5380_reselect (struct Scsi_Host *instance)
+ *
+ * Purpose : does reselection, initializing the instance->connected
+ * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
+ * nexus has been reestablished,
+ *
+ * Inputs : instance - this instance of the NCR5380.
+ */
+
+static void NCR5380_reselect(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned char target_mask;
+ unsigned char lun;
+ unsigned char msg[3];
+ struct NCR5380_cmd *ncmd;
+ struct scsi_cmnd *tmp;
+
+ /*
+ * Disable arbitration, etc. since the host adapter obviously
+ * lost, and tell an interrupted NCR5380_select() to restart.
+ */
+
+ NCR5380_write(MODE_REG, MR_BASE);
+
+ target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
+ if (!target_mask || target_mask & (target_mask - 1)) {
+ shost_printk(KERN_WARNING, instance,
+ "reselect: bad target_mask 0x%02x\n", target_mask);
+ return;
+ }
+
+ /*
+ * At this point, we have detected that our SCSI ID is on the bus,
+ * SEL is true and BSY was false for at least one bus settle delay
+ * (400 ns).
+ *
+ * We must assert BSY ourselves, until the target drops the SEL
+ * signal.
+ */
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
+ if (NCR5380_poll_politely(hostdata,
+ STATUS_REG, SR_SEL, 0, 0) < 0) {
+ shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return;
+ }
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ /*
+ * Wait for target to go into MSGIN.
+ */
+
+ if (NCR5380_poll_politely(hostdata,
+ STATUS_REG, SR_REQ, SR_REQ, 0) < 0) {
+ if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
+ /* BUS FREE phase */
+ return;
+ shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
+ do_abort(instance, 0);
+ return;
+ }
+
+#ifdef CONFIG_SUN3
+ /* acknowledge toggle to MSGIN */
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
+
+ /* peek at the byte without really hitting the bus */
+ msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
+#else
+ {
+ int len = 1;
+ unsigned char *data = msg;
+ unsigned char phase = PHASE_MSGIN;
+
+ NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
+
+ if (len) {
+ do_abort(instance, 0);
+ return;
+ }
+ }
+#endif /* CONFIG_SUN3 */
+
+ if (!(msg[0] & 0x80)) {
+ shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
+ spi_print_msg(msg);
+ printk("\n");
+ do_abort(instance, 0);
+ 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 {
+ int target = ffs(target_mask) - 1;
+
+ 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.
+ */
+ if (do_abort(instance, 0) == 0)
+ hostdata->busy[target] &= ~(1 << lun);
+ return;
+ }
+
+#ifdef CONFIG_SUN3
+ if (sun3_dma_setup_done != tmp) {
+ int count;
+
+ advance_sg_buffer(ncmd);
+
+ count = sun3scsi_dma_xfer_len(hostdata, tmp);
+
+ if (count > 0) {
+ if (tmp->sc_data_direction == DMA_TO_DEVICE)
+ sun3scsi_dma_send_setup(hostdata,
+ ncmd->ptr, count);
+ else
+ sun3scsi_dma_recv_setup(hostdata,
+ ncmd->ptr, count);
+ sun3_dma_setup_done = tmp;
+ }
+ }
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
+#endif /* CONFIG_SUN3 */
+
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ hostdata->connected = tmp;
+ dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
+ scmd_id(tmp), tmp->device->lun);
+}
+
+/**
+ * list_find_cmd - test for presence of a command in a linked list
+ * @haystack: list of commands
+ * @needle: command to search for
+ */
+
+static bool list_find_cmd(struct list_head *haystack,
+ struct scsi_cmnd *needle)
+{
+ struct NCR5380_cmd *ncmd;
+
+ list_for_each_entry(ncmd, haystack, list)
+ if (NCR5380_to_scmd(ncmd) == needle)
+ return true;
+ return false;
+}
+
+/**
+ * list_remove_cmd - remove a command from linked list
+ * @haystack: list of commands
+ * @needle: command to remove
+ */
+
+static bool list_del_cmd(struct list_head *haystack,
+ struct scsi_cmnd *needle)
+{
+ if (list_find_cmd(haystack, needle)) {
+ struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(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;
+ scsi_done(cmd); /* No tag or busy flag to worry about */
+ goto out;
+ }
+
+ if (hostdata->selecting == cmd) {
+ dsprintk(NDEBUG_ABORT, instance,
+ "abort: cmd %p == selecting\n", cmd);
+ hostdata->selecting = NULL;
+ cmd->result = DID_ABORT << 16;
+ complete_cmd(instance, cmd);
+ goto out;
+ }
+
+ if (list_del_cmd(&hostdata->disconnected, cmd)) {
+ dsprintk(NDEBUG_ABORT, instance,
+ "abort: removed %p from disconnected list\n", cmd);
+ /* Can't call NCR5380_select() and send ABORT because that
+ * means releasing the lock. Need a bus reset.
+ */
+ set_host_byte(cmd, DID_ERROR);
+ complete_cmd(instance, cmd);
+ result = FAILED;
+ goto out;
+ }
+
+ if (hostdata->connected == cmd) {
+ dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
+ hostdata->connected = NULL;
+ hostdata->dma_len = 0;
+ if (do_abort(instance, 0) < 0) {
+ 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);
+ complete_cmd(instance, cmd);
+ }
+
+out:
+ if (result == FAILED)
+ dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
+ else {
+ hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
+ 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;
+}
+
+
+static void bus_reset_cleanup(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int i;
+ struct NCR5380_cmd *ncmd;
+
+ /* 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 (hostdata->selecting) {
+ hostdata->selecting->result = DID_RESET << 16;
+ complete_cmd(instance, hostdata->selecting);
+ hostdata->selecting = NULL;
+ }
+
+ list_for_each_entry(ncmd, &hostdata->disconnected, list) {
+ struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
+
+ set_host_byte(cmd, DID_RESET);
+ complete_cmd(instance, cmd);
+ }
+ INIT_LIST_HEAD(&hostdata->disconnected);
+
+ list_for_each_entry(ncmd, &hostdata->autosense, list) {
+ struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
+
+ scsi_done(cmd);
+ }
+ INIT_LIST_HEAD(&hostdata->autosense);
+
+ if (hostdata->connected) {
+ set_host_byte(hostdata->connected, DID_RESET);
+ complete_cmd(instance, hostdata->connected);
+ hostdata->connected = NULL;
+ }
+
+ for (i = 0; i < 8; ++i)
+ hostdata->busy[i] = 0;
+ hostdata->dma_len = 0;
+
+ queue_work(hostdata->work_q, &hostdata->main_task);
+}
+
+/**
+ * NCR5380_host_reset - reset the SCSI host
+ * @cmd: SCSI command undergoing EH
+ *
+ * Returns SUCCESS
+ */
+
+static int NCR5380_host_reset(struct scsi_cmnd *cmd)
+{
+ struct Scsi_Host *instance = cmd->device->host;
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ unsigned long flags;
+ struct NCR5380_cmd *ncmd;
+
+ spin_lock_irqsave(&hostdata->lock, flags);
+
+#if (NDEBUG & NDEBUG_ANY)
+ shost_printk(KERN_INFO, instance, __func__);
+#endif
+ NCR5380_dprint(NDEBUG_ANY, instance);
+ NCR5380_dprint_phase(NDEBUG_ANY, instance);
+
+ list_for_each_entry(ncmd, &hostdata->unissued, list) {
+ struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
+
+ scmd->result = DID_RESET << 16;
+ scsi_done(scmd);
+ }
+ INIT_LIST_HEAD(&hostdata->unissued);
+
+ do_reset(instance);
+ bus_reset_cleanup(instance);
+
+ spin_unlock_irqrestore(&hostdata->lock, flags);
+
+ return SUCCESS;
+}