/* * NCR 5380 generic driver routines. These should make it *trivial* * to implement 5380 SCSI drivers under Linux with a non-trantor * architecture. * * Note that these routines also work with NR53c400 family chips. * * Copyright 1993, Drew Eckhardt * Visionary Computing * (Unix and Linux consulting and custom programming) * drew@colorado.edu * +1 (303) 666-5836 * * For more information, please consult * * NCR 5380 Family * SCSI Protocol Controller * Databook * * NCR Microelectronics * 1635 Aeroplaza Drive * Colorado Springs, CO 80916 * 1+ (719) 578-3400 * 1+ (800) 334-5454 */ /* * With contributions from Ray Van Tassle, Ingmar Baumgart, * Ronald van Cuijlenborg, Alan Cox and others. */ /* Ported to Atari by Roman Hodek and others. */ /* Adapted for the Sun 3 by Sam Creasey. */ /* * Design * * This is a generic 5380 driver. To use it on a different platform, * one simply writes appropriate system specific macros (ie, data * transfer - some PC's will use the I/O bus, 68K's must use * memory mapped) and drops this file in their 'C' wrapper. * * As far as command queueing, two queues are maintained for * each 5380 in the system - commands that haven't been issued yet, * and commands that are currently executing. This means that an * unlimited number of commands may be queued, letting * more commands propagate from the higher driver levels giving higher * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported, * allowing multiple commands to propagate all the way to a SCSI-II device * while a command is already executing. * * * Issues specific to the NCR5380 : * * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead * piece of hardware that requires you to sit in a loop polling for * the REQ signal as long as you are connected. Some devices are * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect * while doing long seek operations. [...] These * broken devices are the exception rather than the rule and I'd rather * spend my time optimizing for the normal case. * * Architecture : * * At the heart of the design is a coroutine, NCR5380_main, * which is started from a workqueue for each NCR5380 host in the * system. It attempts to establish I_T_L or I_T_L_Q nexuses by * removing the commands from the issue queue and calling * NCR5380_select() if a nexus is not established. * * Once a nexus is established, the NCR5380_information_transfer() * phase goes through the various phases as instructed by the target. * if the target goes into MSG IN and sends a DISCONNECT message, * the command structure is placed into the per instance disconnected * queue, and NCR5380_main tries to find more work. If the target is * idle for too long, the system will try to sleep. * * If a command has disconnected, eventually an interrupt will trigger, * calling NCR5380_intr() which will in turn call NCR5380_reselect * to reestablish a nexus. This will run main if necessary. * * On command termination, the done function will be called as * appropriate. * * SCSI pointers are maintained in the SCp field of SCSI command * structures, being initialized after the command is connected * in NCR5380_select, and set as appropriate in NCR5380_information_transfer. * Note that in violation of the standard, an implicit SAVE POINTERS operation * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS. */ /* * Using this file : * This file a skeleton Linux SCSI driver for the NCR 5380 series * of chips. To use it, you write an architecture specific functions * and macros and include this file in your driver. * * These macros MUST be defined : * * NCR5380_read(register) - read from the specified register * * NCR5380_write(register, value) - write to the specific register * * NCR5380_implementation_fields - additional fields needed for this * specific implementation of the NCR5380 * * Either real DMA *or* pseudo DMA may be implemented * * NCR5380_dma_xfer_len - determine size of DMA/PDMA transfer * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380 * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory * NCR5380_dma_residual - residual byte count * * The generic driver is initialized by calling NCR5380_init(instance), * after setting the appropriate host specific fields and ID. */ #ifndef NCR5380_io_delay #define NCR5380_io_delay(x) #endif #ifndef NCR5380_acquire_dma_irq #define NCR5380_acquire_dma_irq(x) (1) #endif #ifndef NCR5380_release_dma_irq #define NCR5380_release_dma_irq(x) #endif static int do_abort(struct Scsi_Host *); static void do_reset(struct Scsi_Host *); /** * initialize_SCp - init the scsi pointer field * @cmd: command block to set up * * Set up the internal fields in the SCSI command. */ static inline void initialize_SCp(struct scsi_cmnd *cmd) { /* * Initialize the Scsi Pointer field so that all of the commands in the * various queues are valid. */ if (scsi_bufflen(cmd)) { cmd->SCp.buffer = scsi_sglist(cmd); cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); cmd->SCp.this_residual = cmd->SCp.buffer->length; } else { cmd->SCp.buffer = NULL; cmd->SCp.buffers_residual = 0; cmd->SCp.ptr = NULL; cmd->SCp.this_residual = 0; } cmd->SCp.Status = 0; cmd->SCp.Message = 0; } /** * NCR5380_poll_politely2 - wait for two chip register values * @hostdata: host private data * @reg1: 5380 register to poll * @bit1: Bitmask to check * @val1: Expected value * @reg2: Second 5380 register to poll * @bit2: Second bitmask to check * @val2: Second expected value * @wait: Time-out in jiffies * * Polls the chip in a reasonably efficient manner waiting for an * event to occur. After a short quick poll we begin to yield the CPU * (if possible). In irq contexts the time-out is arbitrarily limited. * Callers may hold locks as long as they are held in irq mode. * * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT. */ static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata, unsigned int reg1, u8 bit1, u8 val1, unsigned int reg2, u8 bit2, u8 val2, unsigned long wait) { unsigned long n = hostdata->poll_loops; unsigned long deadline = jiffies + wait; do { if ((NCR5380_read(reg1) & bit1) == val1) return 0; if ((NCR5380_read(reg2) & bit2) == val2) return 0; cpu_relax(); } while (n--); if (irqs_disabled() || in_interrupt()) return -ETIMEDOUT; /* Repeatedly sleep for 1 ms until deadline */ while (time_is_after_jiffies(deadline)) { schedule_timeout_uninterruptible(1); if ((NCR5380_read(reg1) & bit1) == val1) return 0; if ((NCR5380_read(reg2) & bit2) == val2) return 0; } return -ETIMEDOUT; } #if NDEBUG static struct { unsigned char mask; const char *name; } signals[] = { {SR_DBP, "PARITY"}, {SR_RST, "RST"}, {SR_BSY, "BSY"}, {SR_REQ, "REQ"}, {SR_MSG, "MSG"}, {SR_CD, "CD"}, {SR_IO, "IO"}, {SR_SEL, "SEL"}, {0, NULL} }, basrs[] = { {BASR_END_DMA_TRANSFER, "END OF DMA"}, {BASR_DRQ, "DRQ"}, {BASR_PARITY_ERROR, "PARITY ERROR"}, {BASR_IRQ, "IRQ"}, {BASR_PHASE_MATCH, "PHASE MATCH"}, {BASR_BUSY_ERROR, "BUSY ERROR"}, {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL} }, icrs[] = { {ICR_ASSERT_RST, "ASSERT RST"}, {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"}, {ICR_ARBITRATION_LOST, "LOST ARB."}, {ICR_ASSERT_ACK, "ASSERT ACK"}, {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, {0, NULL} }, mrs[] = { {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"}, {MR_TARGET, "TARGET"}, {MR_ENABLE_PAR_CHECK, "PARITY CHECK"}, {MR_ENABLE_PAR_INTR, "PARITY INTR"}, {MR_ENABLE_EOP_INTR, "EOP INTR"}, {MR_MONITOR_BSY, "MONITOR BSY"}, {MR_DMA_MODE, "DMA MODE"}, {MR_ARBITRATE, "ARBITRATE"}, {0, NULL} }; /** * NCR5380_print - print scsi bus signals * @instance: adapter state to dump * * Print the SCSI bus signals for debugging purposes */ static void NCR5380_print(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char status, data, basr, mr, icr, i; data = NCR5380_read(CURRENT_SCSI_DATA_REG); status = NCR5380_read(STATUS_REG); mr = NCR5380_read(MODE_REG); icr = NCR5380_read(INITIATOR_COMMAND_REG); basr = NCR5380_read(BUS_AND_STATUS_REG); printk(KERN_DEBUG "SR = 0x%02x : ", status); for (i = 0; signals[i].mask; ++i) if (status & signals[i].mask) printk(KERN_CONT "%s, ", signals[i].name); printk(KERN_CONT "\nBASR = 0x%02x : ", basr); for (i = 0; basrs[i].mask; ++i) if (basr & basrs[i].mask) printk(KERN_CONT "%s, ", basrs[i].name); printk(KERN_CONT "\nICR = 0x%02x : ", icr); for (i = 0; icrs[i].mask; ++i) if (icr & icrs[i].mask) printk(KERN_CONT "%s, ", icrs[i].name); printk(KERN_CONT "\nMR = 0x%02x : ", mr); for (i = 0; mrs[i].mask; ++i) if (mr & mrs[i].mask) printk(KERN_CONT "%s, ", mrs[i].name); printk(KERN_CONT "\n"); } static struct { unsigned char value; const char *name; } phases[] = { {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"}, {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"}, {PHASE_UNKNOWN, "UNKNOWN"} }; /** * NCR5380_print_phase - show SCSI phase * @instance: adapter to dump * * Print the current SCSI phase for debugging purposes */ static void NCR5380_print_phase(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char status; int i; status = NCR5380_read(STATUS_REG); if (!(status & SR_REQ)) shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n"); else { for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i) ; shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name); } } #endif /** * NCR5380_info - report driver and host information * @instance: relevant scsi host instance * * For use as the host template info() handler. */ static const char *NCR5380_info(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); return hostdata->info; } /** * NCR5380_init - initialise an NCR5380 * @instance: adapter to configure * @flags: control flags * * Initializes *instance and corresponding 5380 chip, * with flags OR'd into the initial flags value. * * Notes : I assume that the host, hostno, and id bits have been * set correctly. I don't care about the irq and other fields. * * Returns 0 for success */ static int NCR5380_init(struct Scsi_Host *instance, int flags) { struct NCR5380_hostdata *hostdata = shost_priv(instance); int i; unsigned long deadline; unsigned long accesses_per_ms; instance->max_lun = 7; hostdata->host = instance; hostdata->id_mask = 1 << instance->this_id; hostdata->id_higher_mask = 0; for (i = hostdata->id_mask; i <= 0x80; i <<= 1) if (i > hostdata->id_mask) hostdata->id_higher_mask |= i; for (i = 0; i < 8; ++i) hostdata->busy[i] = 0; hostdata->dma_len = 0; spin_lock_init(&hostdata->lock); hostdata->connected = NULL; hostdata->sensing = NULL; INIT_LIST_HEAD(&hostdata->autosense); INIT_LIST_HEAD(&hostdata->unissued); INIT_LIST_HEAD(&hostdata->disconnected); hostdata->flags = flags; INIT_WORK(&hostdata->main_task, NCR5380_main); hostdata->work_q = alloc_workqueue("ncr5380_%d", WQ_UNBOUND | WQ_MEM_RECLAIM, 1, instance->host_no); if (!hostdata->work_q) return -ENOMEM; snprintf(hostdata->info, sizeof(hostdata->info), "%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}", instance->hostt->name, instance->irq, hostdata->io_port, hostdata->base, instance->can_queue, instance->cmd_per_lun, instance->sg_tablesize, instance->this_id, hostdata->flags & FLAG_DMA_FIXUP ? "DMA_FIXUP " : "", hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "", hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : ""); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_write(MODE_REG, MR_BASE); NCR5380_write(TARGET_COMMAND_REG, 0); NCR5380_write(SELECT_ENABLE_REG, 0); /* Calibrate register polling loop */ i = 0; deadline = jiffies + 1; do { cpu_relax(); } while (time_is_after_jiffies(deadline)); deadline += msecs_to_jiffies(256); do { NCR5380_read(STATUS_REG); ++i; cpu_relax(); } while (time_is_after_jiffies(deadline)); accesses_per_ms = i / 256; hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2; return 0; } /** * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems. * @instance: adapter to check * * If the system crashed, it may have crashed with a connected target and * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the * currently established nexus, which we know nothing about. Failing that * do a bus reset. * * Note that a bus reset will cause the chip to assert IRQ. * * Returns 0 if successful, otherwise -ENXIO. */ static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); int pass; for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) { switch (pass) { case 1: case 3: case 5: shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n"); NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, 0, 5 * HZ); break; case 2: shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n"); do_abort(instance); break; case 4: shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n"); do_reset(instance); /* Wait after a reset; the SCSI standard calls for * 250ms, we wait 500ms to be on the safe side. * But some Toshiba CD-ROMs need ten times that. */ if (hostdata->flags & FLAG_TOSHIBA_DELAY) msleep(2500); else msleep(500); break; case 6: shost_printk(KERN_ERR, instance, "bus locked solid\n"); return -ENXIO; } } return 0; } /** * NCR5380_exit - remove an NCR5380 * @instance: adapter to remove * * Assumes that no more work can be queued (e.g. by NCR5380_intr). */ static void NCR5380_exit(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); cancel_work_sync(&hostdata->main_task); destroy_workqueue(hostdata->work_q); } /** * complete_cmd - finish processing a command and return it to the SCSI ML * @instance: the host instance * @cmd: command to complete */ static void complete_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) { struct NCR5380_hostdata *hostdata = shost_priv(instance); dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd); if (hostdata->sensing == cmd) { /* Autosense processing ends here */ if ((cmd->result & 0xff) != SAM_STAT_GOOD) { scsi_eh_restore_cmnd(cmd, &hostdata->ses); set_host_byte(cmd, DID_ERROR); } else scsi_eh_restore_cmnd(cmd, &hostdata->ses); hostdata->sensing = NULL; } hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun); cmd->scsi_done(cmd); } /** * NCR5380_queue_command - queue a command * @instance: the relevant SCSI adapter * @cmd: SCSI command * * cmd is added to the per-instance issue queue, with minor * twiddling done to the host specific fields of cmd. If the * main coroutine is not running, it is restarted. */ static int NCR5380_queue_command(struct Scsi_Host *instance, struct scsi_cmnd *cmd) { struct NCR5380_hostdata *hostdata = shost_priv(instance); struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); unsigned long flags; #if (NDEBUG & NDEBUG_NO_WRITE) switch (cmd->cmnd[0]) { case WRITE_6: case WRITE_10: shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n"); cmd->result = (DID_ERROR << 16); cmd->scsi_done(cmd); return 0; } #endif /* (NDEBUG & NDEBUG_NO_WRITE) */ cmd->result = 0; if (!NCR5380_acquire_dma_irq(instance)) return SCSI_MLQUEUE_HOST_BUSY; spin_lock_irqsave(&hostdata->lock, flags); /* * Insert the cmd into the issue queue. Note that REQUEST SENSE * commands are added to the head of the queue since any command will * clear the contingent allegiance condition that exists and the * sense data is only guaranteed to be valid while the condition exists. */ if (cmd->cmnd[0] == REQUEST_SENSE) list_add(&ncmd->list, &hostdata->unissued); else list_add_tail(&ncmd->list, &hostdata->unissued); spin_unlock_irqrestore(&hostdata->lock, flags); dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n", cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"); /* Kick off command processing */ queue_work(hostdata->work_q, &hostdata->main_task); return 0; } static inline void maybe_release_dma_irq(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); /* Caller does the locking needed to set & test these data atomically */ if (list_empty(&hostdata->disconnected) && list_empty(&hostdata->unissued) && list_empty(&hostdata->autosense) && !hostdata->connected && !hostdata->selecting) { NCR5380_release_dma_irq(instance); } } /** * dequeue_next_cmd - dequeue a command for processing * @instance: the scsi host instance * * Priority is given to commands on the autosense queue. These commands * need autosense because of a CHECK CONDITION result. * * Returns a command pointer if a command is found for a target that is * not already busy. Otherwise returns NULL. */ static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); struct NCR5380_cmd *ncmd; struct scsi_cmnd *cmd; if (hostdata->sensing || list_empty(&hostdata->autosense)) { list_for_each_entry(ncmd, &hostdata->unissued, list) { cmd = NCR5380_to_scmd(ncmd); dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n", cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun); if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) { list_del(&ncmd->list); dsprintk(NDEBUG_QUEUES, instance, "dequeue: removed %p from issue queue\n", cmd); return cmd; } } } else { /* Autosense processing begins here */ ncmd = list_first_entry(&hostdata->autosense, struct NCR5380_cmd, list); list_del(&ncmd->list); cmd = NCR5380_to_scmd(ncmd); dsprintk(NDEBUG_QUEUES, instance, "dequeue: removed %p from autosense queue\n", cmd); scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0); hostdata->sensing = cmd; return cmd; } return NULL; } static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) { struct NCR5380_hostdata *hostdata = shost_priv(instance); struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); if (hostdata->sensing == cmd) { scsi_eh_restore_cmnd(cmd, &hostdata->ses); list_add(&ncmd->list, &hostdata->autosense); hostdata->sensing = NULL; } else list_add(&ncmd->list, &hostdata->unissued); } /** * NCR5380_main - NCR state machines * * NCR5380_main is a coroutine that runs as long as more work can * be done on the NCR5380 host adapters in a system. Both * NCR5380_queue_command() and NCR5380_intr() will try to start it * in case it is not running. */ static void NCR5380_main(struct work_struct *work) { struct NCR5380_hostdata *hostdata = container_of(work, struct NCR5380_hostdata, main_task); struct Scsi_Host *instance = hostdata->host; int done; do { done = 1; spin_lock_irq(&hostdata->lock); while (!hostdata->connected && !hostdata->selecting) { struct scsi_cmnd *cmd = dequeue_next_cmd(instance); if (!cmd) break; dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd); /* * Attempt to establish an I_T_L nexus here. * On success, instance->hostdata->connected is set. * On failure, we must add the command back to the * issue queue so we can keep trying. */ /* * REQUEST SENSE commands are issued without tagged * queueing, even on SCSI-II devices because the * contingent allegiance condition exists for the * entire unit. */ if (!NCR5380_select(instance, cmd)) { dsprintk(NDEBUG_MAIN, instance, "main: select complete\n"); maybe_release_dma_irq(instance); } else { dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance, "main: select failed, returning %p to queue\n", cmd); requeue_cmd(instance, cmd); } } if (hostdata->connected && !hostdata->dma_len) { dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n"); NCR5380_information_transfer(instance); done = 0; } spin_unlock_irq(&hostdata->lock); if (!done) cond_resched(); } while (!done); } /* * NCR5380_dma_complete - finish DMA transfer * @instance: the scsi host instance * * Called by the interrupt handler when DMA finishes or a phase * mismatch occurs (which would end the DMA transfer). */ static void NCR5380_dma_complete(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); int transferred; unsigned char **data; int *count; int saved_data = 0, overrun = 0; unsigned char p; if (hostdata->read_overruns) { p = hostdata->connected->SCp.phase; if (p & SR_IO) { udelay(10); if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK)) { saved_data = NCR5380_read(INPUT_DATA_REG); overrun = 1; dsprintk(NDEBUG_DMA, instance, "read overrun handled\n"); } } } #ifdef CONFIG_SUN3 if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) { pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n", instance->host_no); BUG(); } if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK)) { pr_err("scsi%d: BASR %02x\n", instance->host_no, NCR5380_read(BUS_AND_STATUS_REG)); pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n", instance->host_no); BUG(); } #endif NCR5380_write(MODE_REG, MR_BASE); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_read(RESET_PARITY_INTERRUPT_REG); transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata); hostdata->dma_len = 0; data = (unsigned char **)&hostdata->connected->SCp.ptr; count = &hostdata->connected->SCp.this_residual; *data += transferred; *count -= transferred; if (hostdata->read_overruns) { int cnt, toPIO; if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) { cnt = toPIO = hostdata->read_overruns; if (overrun) { dsprintk(NDEBUG_DMA, instance, "Got an input overrun, using saved byte\n"); *(*data)++ = saved_data; (*count)--; cnt--; toPIO--; } if (toPIO > 0) { dsprintk(NDEBUG_DMA, instance, "Doing %d byte PIO to 0x%p\n", cnt, *data); NCR5380_transfer_pio(instance, &p, &cnt, data); *count -= toPIO - cnt; } } } } /** * NCR5380_intr - generic NCR5380 irq handler * @irq: interrupt number * @dev_id: device info * * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses * from the disconnected queue, and restarting NCR5380_main() * as required. * * The chip can assert IRQ in any of six different conditions. The IRQ flag * is then cleared by reading the Reset Parity/Interrupt Register (RPIR). * Three of these six conditions are latched in the Bus and Status Register: * - End of DMA (cleared by ending DMA Mode) * - Parity error (cleared by reading RPIR) * - Loss of BSY (cleared by reading RPIR) * Two conditions have flag bits that are not latched: * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode) * - Bus reset (non-maskable) * The remaining condition has no flag bit at all: * - Selection/reselection * * Hence, establishing the cause(s) of any interrupt is partly guesswork. * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor * claimed that "the design of the [DP8490] interrupt logic ensures * interrupts will not be lost (they can be on the DP5380)." * The L5380/53C80 datasheet from LOGIC Devices has more details. * * Checking for bus reset by reading RST is futile because of interrupt * latency, but a bus reset will reset chip logic. Checking for parity error * is unnecessary because that interrupt is never enabled. A Loss of BSY * condition will clear DMA Mode. We can tell when this occurs because the * the Busy Monitor interrupt is enabled together with DMA Mode. */ static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id) { struct Scsi_Host *instance = dev_id; struct NCR5380_hostdata *hostdata = shost_priv(instance); int handled = 0; unsigned char basr; unsigned long flags; spin_lock_irqsave(&hostdata->lock, flags); basr = NCR5380_read(BUS_AND_STATUS_REG); if (basr & BASR_IRQ) { unsigned char mr = NCR5380_read(MODE_REG); unsigned char sr = NCR5380_read(STATUS_REG); dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n", irq, basr, sr, mr); if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) { /* Probably End of DMA, Phase Mismatch or Loss of BSY. * We ack IRQ after clearing Mode Register. Workarounds * for End of DMA errata need to happen in DMA Mode. */ dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n"); if (hostdata->connected) { NCR5380_dma_complete(instance); queue_work(hostdata->work_q, &hostdata->main_task); } else { NCR5380_write(MODE_REG, MR_BASE); NCR5380_read(RESET_PARITY_INTERRUPT_REG); } } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) && (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) { /* Probably reselected */ NCR5380_write(SELECT_ENABLE_REG, 0); NCR5380_read(RESET_PARITY_INTERRUPT_REG); dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n"); if (!hostdata->connected) { NCR5380_reselect(instance); queue_work(hostdata->work_q, &hostdata->main_task); } if (!hostdata->connected) NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); } else { /* Probably Bus Reset */ NCR5380_read(RESET_PARITY_INTERRUPT_REG); dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n"); #ifdef SUN3_SCSI_VME dregs->csr |= CSR_DMA_ENABLE; #endif } handled = 1; } else { dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n"); #ifdef SUN3_SCSI_VME dregs->csr |= CSR_DMA_ENABLE; #endif } spin_unlock_irqrestore(&hostdata->lock, flags); return IRQ_RETVAL(handled); } /* * Function : int NCR5380_select(struct Scsi_Host *instance, * struct scsi_cmnd *cmd) * * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command, * including ARBITRATION, SELECTION, and initial message out for * IDENTIFY and queue messages. * * Inputs : instance - instantiation of the 5380 driver on which this * target lives, cmd - SCSI command to execute. * * Returns cmd if selection failed but should be retried, * NULL if selection failed and should not be retried, or * NULL if selection succeeded (hostdata->connected == cmd). * * Side effects : * If bus busy, arbitration failed, etc, NCR5380_select() will exit * with registers as they should have been on entry - ie * SELECT_ENABLE will be set appropriately, the NCR5380 * will cease to drive any SCSI bus signals. * * If successful : I_T_L or I_T_L_Q nexus will be established, * instance->connected will be set to cmd. * SELECT interrupt will be disabled. * * If failed (no target) : cmd->scsi_done() will be called, and the * cmd->result host byte set to DID_BAD_TARGET. */ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd) __releases(&hostdata->lock) __acquires(&hostdata->lock) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char tmp[3], phase; unsigned char *data; int len; int err; NCR5380_dprint(NDEBUG_ARBITRATION, instance); dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n", instance->this_id); /* * Arbitration and selection phases are slow and involve dropping the * lock, so we have to watch out for EH. An exception handler may * change 'selecting' to NULL. This function will then return NULL * so that the caller will forget about 'cmd'. (During information * transfer phases, EH may change 'connected' to NULL.) */ hostdata->selecting = cmd; /* * Set the phase bits to 0, otherwise the NCR5380 won't drive the * data bus during SELECTION. */ NCR5380_write(TARGET_COMMAND_REG, 0); /* * Start arbitration. */ NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask); NCR5380_write(MODE_REG, MR_ARBITRATE); /* The chip now waits for BUS FREE phase. Then after the 800 ns * Bus Free Delay, arbitration will begin. */ spin_unlock_irq(&hostdata->lock); err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, HZ); spin_lock_irq(&hostdata->lock); if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) { /* Reselection interrupt */ goto out; } if (!hostdata->selecting) { /* Command was aborted */ NCR5380_write(MODE_REG, MR_BASE); goto out; } if (err < 0) { NCR5380_write(MODE_REG, MR_BASE); shost_printk(KERN_ERR, instance, "select: arbitration timeout\n"); goto out; } spin_unlock_irq(&hostdata->lock); /* The SCSI-2 arbitration delay is 2.4 us */ udelay(3); /* Check for lost arbitration */ if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) { NCR5380_write(MODE_REG, MR_BASE); dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n"); spin_lock_irq(&hostdata->lock); goto out; } /* After/during arbitration, BSY should be asserted. * IBM DPES-31080 Version S31Q works now * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY); /* * Again, bus clear + bus settle time is 1.2us, however, this is * a minimum so we'll udelay ceil(1.2) */ if (hostdata->flags & FLAG_TOSHIBA_DELAY) udelay(15); else udelay(2); spin_lock_irq(&hostdata->lock); /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */ if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) goto out; if (!hostdata->selecting) { NCR5380_write(MODE_REG, MR_BASE); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); goto out; } dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n"); /* * Now that we have won arbitration, start Selection process, asserting * the host and target ID's on the SCSI bus. */ NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd))); /* * Raise ATN while SEL is true before BSY goes false from arbitration, * since this is the only way to guarantee that we'll get a MESSAGE OUT * phase immediately after selection. */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL); NCR5380_write(MODE_REG, MR_BASE); /* * Reselect interrupts must be turned off prior to the dropping of BSY, * otherwise we will trigger an interrupt. */ NCR5380_write(SELECT_ENABLE_REG, 0); spin_unlock_irq(&hostdata->lock); /* * The initiator shall then wait at least two deskew delays and release * the BSY signal. */ udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */ /* Reset BSY */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL); /* * Something weird happens when we cease to drive BSY - looks * like the board/chip is letting us do another read before the * appropriate propagation delay has expired, and we're confusing * a BSY signal from ourselves as the target's response to SELECTION. * * A small delay (the 'C++' frontend breaks the pipeline with an * unnecessary jump, making it work on my 386-33/Trantor T128, the * tighter 'C' code breaks and requires this) solves the problem - * the 1 us delay is arbitrary, and only used because this delay will * be the same on other platforms and since it works here, it should * work there. * * wingel suggests that this could be due to failing to wait * one deskew delay. */ udelay(1); dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd)); /* * The SCSI specification calls for a 250 ms timeout for the actual * selection. */ err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY, msecs_to_jiffies(250)); if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) { spin_lock_irq(&hostdata->lock); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_reselect(instance); if (!hostdata->connected) NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n"); goto out; } if (err < 0) { spin_lock_irq(&hostdata->lock); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); /* Can't touch cmd if it has been reclaimed by the scsi ML */ if (hostdata->selecting) { cmd->result = DID_BAD_TARGET << 16; complete_cmd(instance, cmd); dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n"); cmd = NULL; } goto out; } /* * No less than two deskew delays after the initiator detects the * BSY signal is true, it shall release the SEL signal and may * change the DATA BUS. -wingel */ udelay(1); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); /* * Since we followed the SCSI spec, and raised ATN while SEL * was true but before BSY was false during selection, the information * transfer phase should be a MESSAGE OUT phase so that we can send the * IDENTIFY message. */ /* Wait for start of REQ/ACK handshake */ err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ); spin_lock_irq(&hostdata->lock); if (err < 0) { shost_printk(KERN_ERR, instance, "select: REQ timeout\n"); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); goto out; } if (!hostdata->selecting) { do_abort(instance); goto out; } dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n", scmd_id(cmd)); tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun); len = 1; data = tmp; phase = PHASE_MSGOUT; NCR5380_transfer_pio(instance, &phase, &len, &data); if (len) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); cmd->result = DID_ERROR << 16; complete_cmd(instance, cmd); dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n"); cmd = NULL; goto out; } dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n"); hostdata->connected = cmd; hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun; #ifdef SUN3_SCSI_VME dregs->csr |= CSR_INTR; #endif initialize_SCp(cmd); cmd = NULL; out: if (!hostdata->selecting) return NULL; hostdata->selecting = NULL; return cmd; } /* * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, * unsigned char *phase, int *count, unsigned char **data) * * Purpose : transfers data in given phase using polled I/O * * Inputs : instance - instance of driver, *phase - pointer to * what phase is expected, *count - pointer to number of * bytes to transfer, **data - pointer to data pointer. * * Returns : -1 when different phase is entered without transferring * maximum number of bytes, 0 if all bytes are transferred or exit * is in same phase. * * Also, *phase, *count, *data are modified in place. * * XXX Note : handling for bus free may be useful. */ /* * Note : this code is not as quick as it could be, however it * IS 100% reliable, and for the actual data transfer where speed * counts, we will always do a pseudo DMA or DMA transfer. */ static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char p = *phase, tmp; int c = *count; unsigned char *d = *data; /* * The NCR5380 chip will only drive the SCSI bus when the * phase specified in the appropriate bits of the TARGET COMMAND * REGISTER match the STATUS REGISTER */ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p)); do { /* * Wait for assertion of REQ, after which the phase bits will be * valid */ if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0) break; dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n"); /* Check for phase mismatch */ if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) { dsprintk(NDEBUG_PIO, instance, "phase mismatch\n"); NCR5380_dprint_phase(NDEBUG_PIO, instance); break; } /* Do actual transfer from SCSI bus to / from memory */ if (!(p & SR_IO)) NCR5380_write(OUTPUT_DATA_REG, *d); else *d = NCR5380_read(CURRENT_SCSI_DATA_REG); ++d; /* * The SCSI standard suggests that in MSGOUT phase, the initiator * should drop ATN on the last byte of the message phase * after REQ has been asserted for the handshake but before * the initiator raises ACK. */ if (!(p & SR_IO)) { if (!((p & SR_MSG) && c > 1)) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA); NCR5380_dprint(NDEBUG_PIO, instance); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK); } else { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN); NCR5380_dprint(NDEBUG_PIO, instance); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK); } } else { NCR5380_dprint(NDEBUG_PIO, instance); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK); } if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 5 * HZ) < 0) break; dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n"); /* * We have several special cases to consider during REQ/ACK handshaking : * 1. We were in MSGOUT phase, and we are on the last byte of the * message. ATN must be dropped as ACK is dropped. * * 2. We are in a MSGIN phase, and we are on the last byte of the * message. We must exit with ACK asserted, so that the calling * code may raise ATN before dropping ACK to reject the message. * * 3. ACK and ATN are clear and the target may proceed as normal. */ if (!(p == PHASE_MSGIN && c == 1)) { if (p == PHASE_MSGOUT && c > 1) NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); else NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); } } while (--c); dsprintk(NDEBUG_PIO, instance, "residual %d\n", c); *count = c; *data = d; tmp = NCR5380_read(STATUS_REG); /* The phase read from the bus is valid if either REQ is (already) * asserted or if ACK hasn't been released yet. The latter applies if * we're in MSG IN, DATA IN or STATUS and all bytes have been received. */ if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0)) *phase = tmp & PHASE_MASK; else *phase = PHASE_UNKNOWN; if (!c || (*phase == p)) return 0; else return -1; } /** * do_reset - issue a reset command * @instance: adapter to reset * * Issue a reset sequence to the NCR5380 and try and get the bus * back into sane shape. * * This clears the reset interrupt flag because there may be no handler for * it. When the driver is initialized, the NCR5380_intr() handler has not yet * been installed. And when in EH we may have released the ST DMA interrupt. */ static void do_reset(struct Scsi_Host *instance) { struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance); unsigned long flags; local_irq_save(flags); NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK)); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); udelay(50); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG); local_irq_restore(flags); } /** * do_abort - abort the currently established nexus by going to * MESSAGE OUT phase and sending an ABORT message. * @instance: relevant scsi host instance * * Returns 0 on success, -1 on failure. */ static int do_abort(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char *msgptr, phase, tmp; int len; int rc; /* Request message out phase */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); /* * Wait for the target to indicate a valid phase by asserting * REQ. Once this happens, we'll have either a MSGOUT phase * and can immediately send the ABORT message, or we'll have some * other phase and will have to source/sink data. * * We really don't care what value was on the bus or what value * the target sees, so we just handshake. */ rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ); if (rc < 0) goto timeout; tmp = NCR5380_read(STATUS_REG) & PHASE_MASK; NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp)); if (tmp != PHASE_MSGOUT) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK); rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ); if (rc < 0) goto timeout; NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); } tmp = ABORT; msgptr = &tmp; len = 1; phase = PHASE_MSGOUT; NCR5380_transfer_pio(instance, &phase, &len, &msgptr); /* * If we got here, and the command completed successfully, * we're about to go into bus free state. */ return len ? -1 : 0; timeout: NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); return -1; } /* * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, * unsigned char *phase, int *count, unsigned char **data) * * Purpose : transfers data in given phase using either real * or pseudo DMA. * * Inputs : instance - instance of driver, *phase - pointer to * what phase is expected, *count - pointer to number of * bytes to transfer, **data - pointer to data pointer. * * Returns : -1 when different phase is entered without transferring * maximum number of bytes, 0 if all bytes or transferred or exit * is in same phase. * * Also, *phase, *count, *data are modified in place. */ static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) { struct NCR5380_hostdata *hostdata = shost_priv(instance); int c = *count; unsigned char p = *phase; unsigned char *d = *data; unsigned char tmp; int result = 0; if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) { *phase = tmp; return -1; } hostdata->connected->SCp.phase = p; if (p & SR_IO) { if (hostdata->read_overruns) c -= hostdata->read_overruns; else if (hostdata->flags & FLAG_DMA_FIXUP) --c; } dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n", (p & SR_IO) ? "receive" : "send", c, d); #ifdef CONFIG_SUN3 /* send start chain */ sun3scsi_dma_start(c, *data); #endif NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p)); NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY | MR_ENABLE_EOP_INTR); if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) { /* On the Medusa, it is a must to initialize the DMA before * starting the NCR. This is also the cleaner way for the TT. */ if (p & SR_IO) result = NCR5380_dma_recv_setup(hostdata, d, c); else result = NCR5380_dma_send_setup(hostdata, d, c); } /* * On the PAS16 at least I/O recovery delays are not needed here. * Everyone else seems to want them. */ if (p & SR_IO) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); NCR5380_io_delay(1); NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0); } else { NCR5380_io_delay(1); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA); NCR5380_io_delay(1); NCR5380_write(START_DMA_SEND_REG, 0); NCR5380_io_delay(1); } #ifdef CONFIG_SUN3 #ifdef SUN3_SCSI_VME dregs->csr |= CSR_DMA_ENABLE; #endif sun3_dma_active = 1; #endif if (hostdata->flags & FLAG_LATE_DMA_SETUP) { /* On the Falcon, the DMA setup must be done after the last * NCR access, else the DMA setup gets trashed! */ if (p & SR_IO) result = NCR5380_dma_recv_setup(hostdata, d, c); else result = NCR5380_dma_send_setup(hostdata, d, c); } /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */ if (result < 0) return result; /* For real DMA, result is the byte count. DMA interrupt is expected. */ if (result > 0) { hostdata->dma_len = result; return 0; } /* The result is zero iff pseudo DMA send/receive was completed. */ hostdata->dma_len = c; /* * A note regarding the DMA errata workarounds for early NMOS silicon. * * For DMA sends, we want to wait until the last byte has been * transferred out over the bus before we turn off DMA mode. Alas, there * seems to be no terribly good way of doing this on a 5380 under all * conditions. For non-scatter-gather operations, we can wait until REQ * and ACK both go false, or until a phase mismatch occurs. Gather-sends * are nastier, since the device will be expecting more data than we * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we * could test Last Byte Sent to assure transfer (I imagine this is precisely * why this signal was added to the newer chips) but on the older 538[01] * this signal does not exist. The workaround for this lack is a watchdog; * we bail out of the wait-loop after a modest amount of wait-time if * the usual exit conditions are not met. Not a terribly clean or * correct solution :-% * * DMA receive is equally tricky due to a nasty characteristic of the NCR5380. * If the chip is in DMA receive mode, it will respond to a target's * REQ by latching the SCSI data into the INPUT DATA register and asserting * ACK, even if it has _already_ been notified by the DMA controller that * the current DMA transfer has completed! If the NCR5380 is then taken * out of DMA mode, this already-acknowledged byte is lost. This is * not a problem for "one DMA transfer per READ command", because * the situation will never arise... either all of the data is DMA'ed * properly, or the target switches to MESSAGE IN phase to signal a * disconnection (either operation bringing the DMA to a clean halt). * However, in order to handle scatter-receive, we must work around the * problem. The chosen fix is to DMA fewer bytes, then check for the * condition before taking the NCR5380 out of DMA mode. One or two extra * bytes are transferred via PIO as necessary to fill out the original * request. */ if (hostdata->flags & FLAG_DMA_FIXUP) { if (p & SR_IO) { /* * The workaround was to transfer fewer bytes than we * intended to with the pseudo-DMA read function, wait for * the chip to latch the last byte, read it, and then disable * pseudo-DMA mode. * * After REQ is asserted, the NCR5380 asserts DRQ and ACK. * REQ is deasserted when ACK is asserted, and not reasserted * until ACK goes false. Since the NCR5380 won't lower ACK * until DACK is asserted, which won't happen unless we twiddle * the DMA port or we take the NCR5380 out of DMA mode, we * can guarantee that we won't handshake another extra * byte. */ if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ, HZ) < 0) { result = -1; shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n"); } if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, HZ) < 0) { result = -1; shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n"); } d[*count - 1] = NCR5380_read(INPUT_DATA_REG); } else { /* * Wait for the last byte to be sent. If REQ is being asserted for * the byte we're interested, we'll ACK it and it will go false. */ if (NCR5380_poll_politely2(hostdata, BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ, BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) { result = -1; shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n"); } } } NCR5380_dma_complete(instance); return result; } /* * Function : NCR5380_information_transfer (struct Scsi_Host *instance) * * Purpose : run through the various SCSI phases and do as the target * directs us to. Operates on the currently connected command, * instance->connected. * * Inputs : instance, instance for which we are doing commands * * Side effects : SCSI things happen, the disconnected queue will be * modified if a command disconnects, *instance->connected will * change. * * XXX Note : we need to watch for bus free or a reset condition here * to recover from an unexpected bus free condition. */ static void NCR5380_information_transfer(struct Scsi_Host *instance) __releases(&hostdata->lock) __acquires(&hostdata->lock) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char msgout = NOP; int sink = 0; int len; int transfersize; unsigned char *data; unsigned char phase, tmp, extended_msg[10], old_phase = 0xff; struct scsi_cmnd *cmd; #ifdef SUN3_SCSI_VME dregs->csr |= CSR_INTR; #endif while ((cmd = hostdata->connected)) { struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); tmp = NCR5380_read(STATUS_REG); /* We only have a valid SCSI phase when REQ is asserted */ if (tmp & SR_REQ) { phase = (tmp & PHASE_MASK); if (phase != old_phase) { old_phase = phase; NCR5380_dprint_phase(NDEBUG_INFORMATION, instance); } #ifdef CONFIG_SUN3 if (phase == PHASE_CMDOUT && sun3_dma_setup_done != cmd) { int count; if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { ++cmd->SCp.buffer; --cmd->SCp.buffers_residual; cmd->SCp.this_residual = cmd->SCp.buffer->length; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); } count = sun3scsi_dma_xfer_len(hostdata, cmd); if (count > 0) { if (rq_data_dir(cmd->request)) sun3scsi_dma_send_setup(hostdata, cmd->SCp.ptr, count); else sun3scsi_dma_recv_setup(hostdata, cmd->SCp.ptr, count); sun3_dma_setup_done = cmd; } #ifdef SUN3_SCSI_VME dregs->csr |= CSR_INTR; #endif } #endif /* CONFIG_SUN3 */ if (sink && (phase != PHASE_MSGOUT)) { NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp)); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK); while (NCR5380_read(STATUS_REG) & SR_REQ) ; NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); sink = 0; continue; } switch (phase) { case PHASE_DATAOUT: #if (NDEBUG & NDEBUG_NO_DATAOUT) shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n"); sink = 1; do_abort(instance); cmd->result = DID_ERROR << 16; complete_cmd(instance, cmd); hostdata->connected = NULL; return; #endif case PHASE_DATAIN: /* * If there is no room left in the current buffer in the * scatter-gather list, move onto the next one. */ if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { ++cmd->SCp.buffer; --cmd->SCp.buffers_residual; cmd->SCp.this_residual = cmd->SCp.buffer->length; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n", cmd->SCp.this_residual, cmd->SCp.buffers_residual); } /* * The preferred transfer method is going to be * PSEUDO-DMA for systems that are strictly PIO, * since we can let the hardware do the handshaking. * * For this to work, we need to know the transfersize * ahead of time, since the pseudo-DMA code will sit * in an unconditional loop. */ transfersize = 0; if (!cmd->device->borken) transfersize = NCR5380_dma_xfer_len(hostdata, cmd); if (transfersize > 0) { len = transfersize; if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **)&cmd->SCp.ptr)) { /* * If the watchdog timer fires, all future * accesses to this device will use the * polled-IO. */ scmd_printk(KERN_INFO, cmd, "switching to slow handshake\n"); cmd->device->borken = 1; sink = 1; do_abort(instance); cmd->result = DID_ERROR << 16; /* XXX - need to source or sink data here, as appropriate */ } } else { /* Transfer a small chunk so that the * irq mode lock is not held too long. */ transfersize = min(cmd->SCp.this_residual, NCR5380_PIO_CHUNK_SIZE); len = transfersize; NCR5380_transfer_pio(instance, &phase, &len, (unsigned char **)&cmd->SCp.ptr); cmd->SCp.this_residual -= transfersize - len; } #ifdef CONFIG_SUN3 if (sun3_dma_setup_done == cmd) sun3_dma_setup_done = NULL; #endif return; case PHASE_MSGIN: len = 1; data = &tmp; NCR5380_transfer_pio(instance, &phase, &len, &data); cmd->SCp.Message = tmp; switch (tmp) { case ABORT: case COMMAND_COMPLETE: /* Accept message by clearing ACK */ sink = 1; NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); dsprintk(NDEBUG_QUEUES, instance, "COMMAND COMPLETE %p target %d lun %llu\n", cmd, scmd_id(cmd), cmd->device->lun); hostdata->connected = NULL; cmd->result &= ~0xffff; cmd->result |= cmd->SCp.Status; cmd->result |= cmd->SCp.Message << 8; if (cmd->cmnd[0] == REQUEST_SENSE) complete_cmd(instance, cmd); else { if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION || cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) { dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n", cmd); list_add_tail(&ncmd->list, &hostdata->autosense); } else complete_cmd(instance, cmd); } /* * Restore phase bits to 0 so an interrupted selection, * arbitration can resume. */ NCR5380_write(TARGET_COMMAND_REG, 0); /* Enable reselect interrupts */ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); maybe_release_dma_irq(instance); return; case MESSAGE_REJECT: /* Accept message by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); switch (hostdata->last_message) { case HEAD_OF_QUEUE_TAG: case ORDERED_QUEUE_TAG: case SIMPLE_QUEUE_TAG: cmd->device->simple_tags = 0; hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF)); break; default: break; } break; case DISCONNECT: /* Accept message by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); hostdata->connected = NULL; list_add(&ncmd->list, &hostdata->disconnected); dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES, instance, "connected command %p for target %d lun %llu moved to disconnected queue\n", cmd, scmd_id(cmd), cmd->device->lun); /* * Restore phase bits to 0 so an interrupted selection, * arbitration can resume. */ NCR5380_write(TARGET_COMMAND_REG, 0); /* Enable reselect interrupts */ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); #ifdef SUN3_SCSI_VME dregs->csr |= CSR_DMA_ENABLE; #endif return; /* * The SCSI data pointer is *IMPLICITLY* saved on a disconnect * operation, in violation of the SCSI spec so we can safely * ignore SAVE/RESTORE pointers calls. * * Unfortunately, some disks violate the SCSI spec and * don't issue the required SAVE_POINTERS message before * disconnecting, and we have to break spec to remain * compatible. */ case SAVE_POINTERS: case RESTORE_POINTERS: /* Accept message by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); break; case EXTENDED_MESSAGE: /* * Start the message buffer with the EXTENDED_MESSAGE * byte, since spi_print_msg() wants the whole thing. */ extended_msg[0] = EXTENDED_MESSAGE; /* Accept first byte by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); spin_unlock_irq(&hostdata->lock); dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n"); len = 2; data = extended_msg + 1; phase = PHASE_MSGIN; NCR5380_transfer_pio(instance, &phase, &len, &data); dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n", (int)extended_msg[1], (int)extended_msg[2]); if (!len && extended_msg[1] > 0 && extended_msg[1] <= sizeof(extended_msg) - 2) { /* Accept third byte by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); len = extended_msg[1] - 1; data = extended_msg + 3; phase = PHASE_MSGIN; NCR5380_transfer_pio(instance, &phase, &len, &data); dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n", len); switch (extended_msg[2]) { case EXTENDED_SDTR: case EXTENDED_WDTR: tmp = 0; } } else if (len) { shost_printk(KERN_ERR, instance, "error receiving extended message\n"); tmp = 0; } else { shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n", extended_msg[2], extended_msg[1]); tmp = 0; } spin_lock_irq(&hostdata->lock); if (!hostdata->connected) return; /* Fall through to reject message */ /* * If we get something weird that we aren't expecting, * reject it. */ default: if (tmp == EXTENDED_MESSAGE) scmd_printk(KERN_INFO, cmd, "rejecting unknown extended message code %02x, length %d\n", extended_msg[2], extended_msg[1]); else if (tmp) scmd_printk(KERN_INFO, cmd, "rejecting unknown message code %02x\n", tmp); msgout = MESSAGE_REJECT; NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); break; } /* switch (tmp) */ break; case PHASE_MSGOUT: len = 1; data = &msgout; hostdata->last_message = msgout; NCR5380_transfer_pio(instance, &phase, &len, &data); if (msgout == ABORT) { hostdata->connected = NULL; cmd->result = DID_ERROR << 16; complete_cmd(instance, cmd); maybe_release_dma_irq(instance); NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); return; } msgout = NOP; break; case PHASE_CMDOUT: len = cmd->cmd_len; data = cmd->cmnd; /* * XXX for performance reasons, on machines with a * PSEUDO-DMA architecture we should probably * use the dma transfer function. */ NCR5380_transfer_pio(instance, &phase, &len, &data); break; case PHASE_STATIN: len = 1; data = &tmp; NCR5380_transfer_pio(instance, &phase, &len, &data); cmd->SCp.Status = tmp; break; default: shost_printk(KERN_ERR, instance, "unknown phase\n"); NCR5380_dprint(NDEBUG_ANY, instance); } /* switch(phase) */ } else { spin_unlock_irq(&hostdata->lock); NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ); spin_lock_irq(&hostdata->lock); } } } /* * Function : void NCR5380_reselect (struct Scsi_Host *instance) * * Purpose : does reselection, initializing the instance->connected * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q * nexus has been reestablished, * * Inputs : instance - this instance of the NCR5380. */ static void NCR5380_reselect(struct Scsi_Host *instance) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned char target_mask; unsigned char lun; unsigned char msg[3]; struct NCR5380_cmd *ncmd; struct scsi_cmnd *tmp; /* * Disable arbitration, etc. since the host adapter obviously * lost, and tell an interrupted NCR5380_select() to restart. */ NCR5380_write(MODE_REG, MR_BASE); target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask); dsprintk(NDEBUG_RESELECTION, instance, "reselect\n"); /* * At this point, we have detected that our SCSI ID is on the bus, * SEL is true and BSY was false for at least one bus settle delay * (400 ns). * * We must assert BSY ourselves, until the target drops the SEL * signal. */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY); if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); return; } NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); /* * Wait for target to go into MSGIN. */ if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) { do_abort(instance); return; } #ifdef CONFIG_SUN3 /* acknowledge toggle to MSGIN */ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN)); /* peek at the byte without really hitting the bus */ msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG); #else { int len = 1; unsigned char *data = msg; unsigned char phase = PHASE_MSGIN; NCR5380_transfer_pio(instance, &phase, &len, &data); if (len) { do_abort(instance); return; } } #endif /* CONFIG_SUN3 */ if (!(msg[0] & 0x80)) { shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got "); spi_print_msg(msg); printk("\n"); do_abort(instance); return; } lun = msg[0] & 0x07; /* * We need to add code for SCSI-II to track which devices have * I_T_L_Q nexuses established, and which have simple I_T_L * nexuses so we can chose to do additional data transfer. */ /* * Find the command corresponding to the I_T_L or I_T_L_Q nexus we * just reestablished, and remove it from the disconnected queue. */ tmp = NULL; list_for_each_entry(ncmd, &hostdata->disconnected, list) { struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd); if (target_mask == (1 << scmd_id(cmd)) && lun == (u8)cmd->device->lun) { list_del(&ncmd->list); tmp = cmd; break; } } if (tmp) { dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance, "reselect: removed %p from disconnected queue\n", tmp); } else { shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n", target_mask, lun); /* * Since we have an established nexus that we can't do anything * with, we must abort it. */ do_abort(instance); return; } #ifdef CONFIG_SUN3 if (sun3_dma_setup_done != tmp) { int count; if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) { ++tmp->SCp.buffer; --tmp->SCp.buffers_residual; tmp->SCp.this_residual = tmp->SCp.buffer->length; tmp->SCp.ptr = sg_virt(tmp->SCp.buffer); } count = sun3scsi_dma_xfer_len(hostdata, tmp); if (count > 0) { if (rq_data_dir(tmp->request)) sun3scsi_dma_send_setup(hostdata, tmp->SCp.ptr, count); else sun3scsi_dma_recv_setup(hostdata, tmp->SCp.ptr, count); sun3_dma_setup_done = tmp; } } NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK); #endif /* CONFIG_SUN3 */ /* Accept message by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); hostdata->connected = tmp; dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n", scmd_id(tmp), tmp->device->lun); } /** * list_find_cmd - test for presence of a command in a linked list * @haystack: list of commands * @needle: command to search for */ static bool list_find_cmd(struct list_head *haystack, struct scsi_cmnd *needle) { struct NCR5380_cmd *ncmd; list_for_each_entry(ncmd, haystack, list) if (NCR5380_to_scmd(ncmd) == needle) return true; return false; } /** * list_remove_cmd - remove a command from linked list * @haystack: list of commands * @needle: command to remove */ static bool list_del_cmd(struct list_head *haystack, struct scsi_cmnd *needle) { if (list_find_cmd(haystack, needle)) { struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle); list_del(&ncmd->list); return true; } return false; } /** * NCR5380_abort - scsi host eh_abort_handler() method * @cmd: the command to be aborted * * Try to abort a given command by removing it from queues and/or sending * the target an abort message. This may not succeed in causing a target * to abort the command. Nonetheless, the low-level driver must forget about * the command because the mid-layer reclaims it and it may be re-issued. * * The normal path taken by a command is as follows. For EH we trace this * same path to locate and abort the command. * * unissued -> selecting -> [unissued -> selecting ->]... connected -> * [disconnected -> connected ->]... * [autosense -> connected ->] done * * If cmd was not found at all then presumably it has already been completed, * in which case return SUCCESS to try to avoid further EH measures. * * If the command has not completed yet, we must not fail to find it. * We have no option but to forget the aborted command (even if it still * lacks sense data). The mid-layer may re-issue a command that is in error * recovery (see scsi_send_eh_cmnd), but the logic and data structures in * this driver are such that a command can appear on one queue only. * * The lock protects driver data structures, but EH handlers also use it * to serialize their own execution and prevent their own re-entry. */ static int NCR5380_abort(struct scsi_cmnd *cmd) { struct Scsi_Host *instance = cmd->device->host; struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned long flags; int result = SUCCESS; spin_lock_irqsave(&hostdata->lock, flags); #if (NDEBUG & NDEBUG_ANY) scmd_printk(KERN_INFO, cmd, __func__); #endif NCR5380_dprint(NDEBUG_ANY, instance); NCR5380_dprint_phase(NDEBUG_ANY, instance); if (list_del_cmd(&hostdata->unissued, cmd)) { dsprintk(NDEBUG_ABORT, instance, "abort: removed %p from issue queue\n", cmd); cmd->result = DID_ABORT << 16; cmd->scsi_done(cmd); /* No tag or busy flag to worry about */ goto out; } if (hostdata->selecting == cmd) { dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p == selecting\n", cmd); hostdata->selecting = NULL; cmd->result = DID_ABORT << 16; complete_cmd(instance, cmd); goto out; } if (list_del_cmd(&hostdata->disconnected, cmd)) { dsprintk(NDEBUG_ABORT, instance, "abort: removed %p from disconnected list\n", cmd); /* Can't call NCR5380_select() and send ABORT because that * means releasing the lock. Need a bus reset. */ set_host_byte(cmd, DID_ERROR); complete_cmd(instance, cmd); result = FAILED; goto out; } if (hostdata->connected == cmd) { dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd); hostdata->connected = NULL; hostdata->dma_len = 0; if (do_abort(instance)) { set_host_byte(cmd, DID_ERROR); complete_cmd(instance, cmd); result = FAILED; goto out; } set_host_byte(cmd, DID_ABORT); complete_cmd(instance, cmd); goto out; } if (list_del_cmd(&hostdata->autosense, cmd)) { dsprintk(NDEBUG_ABORT, instance, "abort: removed %p from sense queue\n", cmd); set_host_byte(cmd, DID_ERROR); complete_cmd(instance, cmd); } out: if (result == FAILED) dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd); else dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd); queue_work(hostdata->work_q, &hostdata->main_task); maybe_release_dma_irq(instance); spin_unlock_irqrestore(&hostdata->lock, flags); return result; } /** * NCR5380_host_reset - reset the SCSI host * @cmd: SCSI command undergoing EH * * Returns SUCCESS */ static int NCR5380_host_reset(struct scsi_cmnd *cmd) { struct Scsi_Host *instance = cmd->device->host; struct NCR5380_hostdata *hostdata = shost_priv(instance); int i; unsigned long flags; struct NCR5380_cmd *ncmd; spin_lock_irqsave(&hostdata->lock, flags); #if (NDEBUG & NDEBUG_ANY) scmd_printk(KERN_INFO, cmd, __func__); #endif NCR5380_dprint(NDEBUG_ANY, instance); NCR5380_dprint_phase(NDEBUG_ANY, instance); do_reset(instance); /* reset NCR registers */ NCR5380_write(MODE_REG, MR_BASE); NCR5380_write(TARGET_COMMAND_REG, 0); NCR5380_write(SELECT_ENABLE_REG, 0); /* After the reset, there are no more connected or disconnected commands * and no busy units; so clear the low-level status here to avoid * conflicts when the mid-level code tries to wake up the affected * commands! */ if (list_del_cmd(&hostdata->unissued, cmd)) { cmd->result = DID_RESET << 16; cmd->scsi_done(cmd); } if (hostdata->selecting) { hostdata->selecting->result = DID_RESET << 16; complete_cmd(instance, hostdata->selecting); hostdata->selecting = NULL; } list_for_each_entry(ncmd, &hostdata->disconnected, list) { struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd); set_host_byte(cmd, DID_RESET); complete_cmd(instance, cmd); } INIT_LIST_HEAD(&hostdata->disconnected); list_for_each_entry(ncmd, &hostdata->autosense, list) { struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd); set_host_byte(cmd, DID_RESET); cmd->scsi_done(cmd); } INIT_LIST_HEAD(&hostdata->autosense); if (hostdata->connected) { set_host_byte(hostdata->connected, DID_RESET); complete_cmd(instance, hostdata->connected); hostdata->connected = NULL; } for (i = 0; i < 8; ++i) hostdata->busy[i] = 0; hostdata->dma_len = 0; queue_work(hostdata->work_q, &hostdata->main_task); maybe_release_dma_irq(instance); spin_unlock_irqrestore(&hostdata->lock, flags); return SUCCESS; }