diff options
Diffstat (limited to 'drivers/scsi/libata-eh.c')
| -rw-r--r-- | drivers/scsi/libata-eh.c | 1154 |
1 files changed, 1147 insertions, 7 deletions
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c index 16db6221171..e401f353f84 100644 --- a/drivers/scsi/libata-eh.c +++ b/drivers/scsi/libata-eh.c @@ -44,6 +44,53 @@ #include "libata.h" +static void __ata_port_freeze(struct ata_port *ap); + +static void ata_ering_record(struct ata_ering *ering, int is_io, + unsigned int err_mask) +{ + struct ata_ering_entry *ent; + + WARN_ON(!err_mask); + + ering->cursor++; + ering->cursor %= ATA_ERING_SIZE; + + ent = &ering->ring[ering->cursor]; + ent->is_io = is_io; + ent->err_mask = err_mask; + ent->timestamp = get_jiffies_64(); +} + +static struct ata_ering_entry * ata_ering_top(struct ata_ering *ering) +{ + struct ata_ering_entry *ent = &ering->ring[ering->cursor]; + if (!ent->err_mask) + return NULL; + return ent; +} + +static int ata_ering_map(struct ata_ering *ering, + int (*map_fn)(struct ata_ering_entry *, void *), + void *arg) +{ + int idx, rc = 0; + struct ata_ering_entry *ent; + + idx = ering->cursor; + do { + ent = &ering->ring[idx]; + if (!ent->err_mask) + break; + rc = map_fn(ent, arg); + if (rc) + break; + idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE; + } while (idx != ering->cursor); + + return rc; +} + /** * ata_scsi_timed_out - SCSI layer time out callback * @cmd: timed out SCSI command @@ -55,6 +102,8 @@ * from finishing it by setting EH_SCHEDULED and return * EH_NOT_HANDLED. * + * TODO: kill this function once old EH is gone. + * * LOCKING: * Called from timer context * @@ -67,10 +116,16 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd) struct ata_port *ap = ata_shost_to_port(host); unsigned long flags; struct ata_queued_cmd *qc; - enum scsi_eh_timer_return ret = EH_HANDLED; + enum scsi_eh_timer_return ret; DPRINTK("ENTER\n"); + if (ap->ops->error_handler) { + ret = EH_NOT_HANDLED; + goto out; + } + + ret = EH_HANDLED; spin_lock_irqsave(&ap->host_set->lock, flags); qc = ata_qc_from_tag(ap, ap->active_tag); if (qc) { @@ -81,6 +136,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd) } spin_unlock_irqrestore(&ap->host_set->lock, flags); + out: DPRINTK("EXIT, ret=%d\n", ret); return ret; } @@ -100,21 +156,141 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd) void ata_scsi_error(struct Scsi_Host *host) { struct ata_port *ap = ata_shost_to_port(host); + spinlock_t *hs_lock = &ap->host_set->lock; + int i, repeat_cnt = ATA_EH_MAX_REPEAT; + unsigned long flags; DPRINTK("ENTER\n"); - /* synchronize with IRQ handler and port task */ - spin_unlock_wait(&ap->host_set->lock); + /* synchronize with port task */ ata_port_flush_task(ap); - WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL); + /* synchronize with host_set lock and sort out timeouts */ + + /* For new EH, all qcs are finished in one of three ways - + * normal completion, error completion, and SCSI timeout. + * Both cmpletions can race against SCSI timeout. When normal + * completion wins, the qc never reaches EH. When error + * completion wins, the qc has ATA_QCFLAG_FAILED set. + * + * When SCSI timeout wins, things are a bit more complex. + * Normal or error completion can occur after the timeout but + * before this point. In such cases, both types of + * completions are honored. A scmd is determined to have + * timed out iff its associated qc is active and not failed. + */ + if (ap->ops->error_handler) { + struct scsi_cmnd *scmd, *tmp; + int nr_timedout = 0; + + spin_lock_irqsave(hs_lock, flags); + + list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) { + struct ata_queued_cmd *qc; + + for (i = 0; i < ATA_MAX_QUEUE; i++) { + qc = __ata_qc_from_tag(ap, i); + if (qc->flags & ATA_QCFLAG_ACTIVE && + qc->scsicmd == scmd) + break; + } + + if (i < ATA_MAX_QUEUE) { + /* the scmd has an associated qc */ + if (!(qc->flags & ATA_QCFLAG_FAILED)) { + /* which hasn't failed yet, timeout */ + qc->err_mask |= AC_ERR_TIMEOUT; + qc->flags |= ATA_QCFLAG_FAILED; + nr_timedout++; + } + } else { + /* Normal completion occurred after + * SCSI timeout but before this point. + * Successfully complete it. + */ + scmd->retries = scmd->allowed; + scsi_eh_finish_cmd(scmd, &ap->eh_done_q); + } + } - ap->ops->eng_timeout(ap); + /* If we have timed out qcs. They belong to EH from + * this point but the state of the controller is + * unknown. Freeze the port to make sure the IRQ + * handler doesn't diddle with those qcs. This must + * be done atomically w.r.t. setting QCFLAG_FAILED. + */ + if (nr_timedout) + __ata_port_freeze(ap); + spin_unlock_irqrestore(hs_lock, flags); + } else + spin_unlock_wait(hs_lock); + + repeat: + /* invoke error handler */ + if (ap->ops->error_handler) { + /* fetch & clear EH info */ + spin_lock_irqsave(hs_lock, flags); + + memset(&ap->eh_context, 0, sizeof(ap->eh_context)); + ap->eh_context.i = ap->eh_info; + memset(&ap->eh_info, 0, sizeof(ap->eh_info)); + + ap->flags &= ~ATA_FLAG_EH_PENDING; + + spin_unlock_irqrestore(hs_lock, flags); + + /* invoke EH */ + ap->ops->error_handler(ap); + + /* Exception might have happend after ->error_handler + * recovered the port but before this point. Repeat + * EH in such case. + */ + spin_lock_irqsave(hs_lock, flags); + + if (ap->flags & ATA_FLAG_EH_PENDING) { + if (--repeat_cnt) { + ata_port_printk(ap, KERN_INFO, + "EH pending after completion, " + "repeating EH (cnt=%d)\n", repeat_cnt); + spin_unlock_irqrestore(hs_lock, flags); + goto repeat; + } + ata_port_printk(ap, KERN_ERR, "EH pending after %d " + "tries, giving up\n", ATA_EH_MAX_REPEAT); + } + + /* this run is complete, make sure EH info is clear */ + memset(&ap->eh_info, 0, sizeof(ap->eh_info)); + + /* Clear host_eh_scheduled while holding hs_lock such + * that if exception occurs after this point but + * before EH completion, SCSI midlayer will + * re-initiate EH. + */ + host->host_eh_scheduled = 0; + + spin_unlock_irqrestore(hs_lock, flags); + } else { + WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL); + ap->ops->eng_timeout(ap); + } + + /* finish or retry handled scmd's and clean up */ WARN_ON(host->host_failed || !list_empty(&host->eh_cmd_q)); scsi_eh_flush_done_q(&ap->eh_done_q); + /* clean up */ + spin_lock_irqsave(hs_lock, flags); + + if (ap->flags & ATA_FLAG_RECOVERED) + ata_port_printk(ap, KERN_INFO, "EH complete\n"); + ap->flags &= ~ATA_FLAG_RECOVERED; + + spin_unlock_irqrestore(hs_lock, flags); + DPRINTK("EXIT\n"); } @@ -133,6 +309,8 @@ void ata_scsi_error(struct Scsi_Host *host) * an interrupt was not delivered to the driver, even though the * transaction completed successfully. * + * TODO: kill this function once old EH is gone. + * * LOCKING: * Inherited from SCSI layer (none, can sleep) */ @@ -167,8 +345,9 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc) /* ack bmdma irq events */ ap->ops->irq_clear(ap); - printk(KERN_ERR "ata%u: command 0x%x timeout, stat 0x%x host_stat 0x%x\n", - ap->id, qc->tf.command, drv_stat, host_stat); + ata_dev_printk(qc->dev, KERN_ERR, "command 0x%x timeout, " + "stat 0x%x host_stat 0x%x\n", + qc->tf.command, drv_stat, host_stat); /* complete taskfile transaction */ qc->err_mask |= AC_ERR_TIMEOUT; @@ -197,6 +376,8 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc) * an interrupt was not delivered to the driver, even though the * transaction completed successfully. * + * TODO: kill this function once old EH is gone. + * * LOCKING: * Inherited from SCSI layer (none, can sleep) */ @@ -209,6 +390,190 @@ void ata_eng_timeout(struct ata_port *ap) DPRINTK("EXIT\n"); } +/** + * ata_qc_schedule_eh - schedule qc for error handling + * @qc: command to schedule error handling for + * + * Schedule error handling for @qc. EH will kick in as soon as + * other commands are drained. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + */ +void ata_qc_schedule_eh(struct ata_queued_cmd *qc) +{ + struct ata_port *ap = qc->ap; + + WARN_ON(!ap->ops->error_handler); + + qc->flags |= ATA_QCFLAG_FAILED; + qc->ap->flags |= ATA_FLAG_EH_PENDING; + + /* The following will fail if timeout has already expired. + * ata_scsi_error() takes care of such scmds on EH entry. + * Note that ATA_QCFLAG_FAILED is unconditionally set after + * this function completes. + */ + scsi_req_abort_cmd(qc->scsicmd); +} + +/** + * ata_port_schedule_eh - schedule error handling without a qc + * @ap: ATA port to schedule EH for + * + * Schedule error handling for @ap. EH will kick in as soon as + * all commands are drained. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + */ +void ata_port_schedule_eh(struct ata_port *ap) +{ + WARN_ON(!ap->ops->error_handler); + + ap->flags |= ATA_FLAG_EH_PENDING; + ata_schedule_scsi_eh(ap->host); + + DPRINTK("port EH scheduled\n"); +} + +/** + * ata_port_abort - abort all qc's on the port + * @ap: ATA port to abort qc's for + * + * Abort all active qc's of @ap and schedule EH. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + * + * RETURNS: + * Number of aborted qc's. + */ +int ata_port_abort(struct ata_port *ap) +{ + int tag, nr_aborted = 0; + + WARN_ON(!ap->ops->error_handler); + + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag); + + if (qc) { + qc->flags |= ATA_QCFLAG_FAILED; + ata_qc_complete(qc); + nr_aborted++; + } + } + + if (!nr_aborted) + ata_port_schedule_eh(ap); + + return nr_aborted; +} + +/** + * __ata_port_freeze - freeze port + * @ap: ATA port to freeze + * + * This function is called when HSM violation or some other + * condition disrupts normal operation of the port. Frozen port + * is not allowed to perform any operation until the port is + * thawed, which usually follows a successful reset. + * + * ap->ops->freeze() callback can be used for freezing the port + * hardware-wise (e.g. mask interrupt and stop DMA engine). If a + * port cannot be frozen hardware-wise, the interrupt handler + * must ack and clear interrupts unconditionally while the port + * is frozen. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + */ +static void __ata_port_freeze(struct ata_port *ap) +{ + WARN_ON(!ap->ops->error_handler); + + if (ap->ops->freeze) + ap->ops->freeze(ap); + + ap->flags |= ATA_FLAG_FROZEN; + + DPRINTK("ata%u port frozen\n", ap->id); +} + +/** + * ata_port_freeze - abort & freeze port + * @ap: ATA port to freeze + * + * Abort and freeze @ap. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + * + * RETURNS: + * Number of aborted commands. + */ +int ata_port_freeze(struct ata_port *ap) +{ + int nr_aborted; + + WARN_ON(!ap->ops->error_handler); + + nr_aborted = ata_port_abort(ap); + __ata_port_freeze(ap); + + return nr_aborted; +} + +/** + * ata_eh_freeze_port - EH helper to freeze port + * @ap: ATA port to freeze + * + * Freeze @ap. + * + * LOCKING: + * None. + */ +void ata_eh_freeze_port(struct ata_port *ap) +{ + unsigned long flags; + + if (!ap->ops->error_handler) + return; + + spin_lock_irqsave(&ap->host_set->lock, flags); + __ata_port_freeze(ap); + spin_unlock_irqrestore(&ap->host_set->lock, flags); +} + +/** + * ata_port_thaw_port - EH helper to thaw port + * @ap: ATA port to thaw + * + * Thaw frozen port @ap. + * + * LOCKING: + * None. + */ +void ata_eh_thaw_port(struct ata_port *ap) +{ + unsigned long flags; + + if (!ap->ops->error_handler) + return; + + spin_lock_irqsave(&ap->host_set->lock, flags); + + ap->flags &= ~ATA_FLAG_FROZEN; + + if (ap->ops->thaw) + ap->ops->thaw(ap); + + spin_unlock_irqrestore(&ap->host_set->lock, flags); + + DPRINTK("ata%u port thawed\n", ap->id); +} + static void ata_eh_scsidone(struct scsi_cmnd *scmd) { /* nada */ @@ -261,3 +626,778 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc) scmd->retries--; __ata_eh_qc_complete(qc); } + +/** + * ata_eh_about_to_do - about to perform eh_action + * @ap: target ATA port + * @action: action about to be performed + * + * Called just before performing EH actions to clear related bits + * in @ap->eh_info such that eh actions are not unnecessarily + * repeated. + * + * LOCKING: + * None. + */ +static void ata_eh_about_to_do(struct ata_port *ap, unsigned int action) +{ + unsigned long flags; + + spin_lock_irqsave(&ap->host_set->lock, flags); + ap->eh_info.action &= ~action; + ap->flags |= ATA_FLAG_RECOVERED; + spin_unlock_irqrestore(&ap->host_set->lock, flags); +} + +/** + * ata_err_string - convert err_mask to descriptive string + * @err_mask: error mask to convert to string + * + * Convert @err_mask to descriptive string. Errors are + * prioritized according to severity and only the most severe + * error is reported. + * + * LOCKING: + * None. + * + * RETURNS: + * Descriptive string for @err_mask + */ +static const char * ata_err_string(unsigned int err_mask) +{ + if (err_mask & AC_ERR_HOST_BUS) + return "host bus error"; + if (err_mask & AC_ERR_ATA_BUS) + return "ATA bus error"; + if (err_mask & AC_ERR_TIMEOUT) + return "timeout"; + if (err_mask & AC_ERR_HSM) + return "HSM violation"; + if (err_mask & AC_ERR_SYSTEM) + return "internal error"; + if (err_mask & AC_ERR_MEDIA) + return "media error"; + if (err_mask & AC_ERR_INVALID) + return "invalid argument"; + if (err_mask & AC_ERR_DEV) + return "device error"; + return "unknown error"; +} + +/** + * atapi_eh_request_sense - perform ATAPI REQUEST_SENSE + * @dev: device to perform REQUEST_SENSE to + * @sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long) + * + * Perform ATAPI REQUEST_SENSE after the device reported CHECK + * SENSE. This function is EH helper. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, AC_ERR_* mask on failure + */ +static unsigned int atapi_eh_request_sense(struct ata_device *dev, + unsigned char *sense_buf) +{ + struct ata_port *ap = dev->ap; + struct ata_taskfile tf; + u8 cdb[ATAPI_CDB_LEN]; + + DPRINTK("ATAPI request sense\n"); + + ata_tf_init(dev, &tf); + + /* FIXME: is this needed? */ + memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE); + + /* XXX: why tf_read here? */ + ap->ops->tf_read(ap, &tf); + + /* fill these in, for the case where they are -not- overwritten */ + sense_buf[0] = 0x70; + sense_buf[2] = tf.feature >> 4; + + memset(cdb, 0, ATAPI_CDB_LEN); + cdb[0] = REQUEST_SENSE; + cdb[4] = SCSI_SENSE_BUFFERSIZE; + + tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; + tf.command = ATA_CMD_PACKET; + + /* is it pointless to prefer PIO for "safety reasons"? */ + if (ap->flags & ATA_FLAG_PIO_DMA) { + tf.protocol = ATA_PROT_ATAPI_DMA; + tf.feature |= ATAPI_PKT_DMA; + } else { + tf.protocol = ATA_PROT_ATAPI; + tf.lbam = (8 * 1024) & 0xff; + tf.lbah = (8 * 1024) >> 8; + } + + return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE, + sense_buf, SCSI_SENSE_BUFFERSIZE); +} + +/** + * ata_eh_analyze_serror - analyze SError for a failed port + * @ap: ATA port to analyze SError for + * + * Analyze SError if available and further determine cause of + * failure. + * + * LOCKING: + * None. + */ +static void ata_eh_analyze_serror(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + u32 serror = ehc->i.serror; + unsigned int err_mask = 0, action = 0; + + if (serror & SERR_PERSISTENT) { + err_mask |= AC_ERR_ATA_BUS; + action |= ATA_EH_HARDRESET; + } + if (serror & + (SERR_DATA_RECOVERED | SERR_COMM_RECOVERED | SERR_DATA)) { + err_mask |= AC_ERR_ATA_BUS; + action |= ATA_EH_SOFTRESET; + } + if (serror & SERR_PROTOCOL) { + err_mask |= AC_ERR_HSM; + action |= ATA_EH_SOFTRESET; + } + if (serror & SERR_INTERNAL) { + err_mask |= AC_ERR_SYSTEM; + action |= ATA_EH_SOFTRESET; + } + if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG)) { + err_mask |= AC_ERR_ATA_BUS; + action |= ATA_EH_HARDRESET; + } + + ehc->i.err_mask |= err_mask; + ehc->i.action |= action; +} + +/** + * ata_eh_analyze_tf - analyze taskfile of a failed qc + * @qc: qc to analyze + * @tf: Taskfile registers to analyze + * + * Analyze taskfile of @qc and further determine cause of + * failure. This function also requests ATAPI sense data if + * avaliable. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * Determined recovery action + */ +static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc, + const struct ata_taskfile *tf) +{ + unsigned int tmp, action = 0; + u8 stat = tf->command, err = tf->feature; + + if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) { + qc->err_mask |= AC_ERR_HSM; + return ATA_EH_SOFTRESET; + } + + if (!(qc->err_mask & AC_ERR_DEV)) + return 0; + + switch (qc->dev->class) { + case ATA_DEV_ATA: + if (err & ATA_ICRC) + qc->err_mask |= AC_ERR_ATA_BUS; + if (err & ATA_UNC) + qc->err_mask |= AC_ERR_MEDIA; + if (err & ATA_IDNF) + qc->err_mask |= AC_ERR_INVALID; + break; + + case ATA_DEV_ATAPI: + tmp = atapi_eh_request_sense(qc->dev, + qc->scsicmd->sense_buffer); + if (!tmp) { + /* ATA_QCFLAG_SENSE_VALID is used to tell + * atapi_qc_complete() that sense data is + * already valid. + * + * TODO: interpret sense data and set + * appropriate err_mask. + */ + qc->flags |= ATA_QCFLAG_SENSE_VALID; + } else + qc->err_mask |= tmp; + } + + if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS)) + action |= ATA_EH_SOFTRESET; + + return action; +} + +static int ata_eh_categorize_ering_entry(struct ata_ering_entry *ent) +{ + if (ent->err_mask & (AC_ERR_ATA_BUS | AC_ERR_TIMEOUT)) + return 1; + + if (ent->is_io) { + if (ent->err_mask & AC_ERR_HSM) + return 1; + if ((ent->err_mask & + (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV) + return 2; + } + + return 0; +} + +struct speed_down_needed_arg { + u64 since; + int nr_errors[3]; +}; + +static int speed_down_needed_cb(struct ata_ering_entry *ent, void *void_arg) +{ + struct speed_down_needed_arg *arg = void_arg; + + if (ent->timestamp < arg->since) + return -1; + + arg->nr_errors[ata_eh_categorize_ering_entry(ent)]++; + return 0; +} + +/** + * ata_eh_speed_down_needed - Determine wheter speed down is necessary + * @dev: Device of interest + * + * This function examines error ring of @dev and determines + * whether speed down is necessary. Speed down is necessary if + * there have been more than 3 of Cat-1 errors or 10 of Cat-2 + * errors during last 15 minutes. + * + * Cat-1 errors are ATA_BUS, TIMEOUT for any command and HSM + * violation for known supported commands. + * + * Cat-2 errors are unclassified DEV error for known supported + * command. + * + * LOCKING: + * Inherited from caller. + * + * RETURNS: + * 1 if speed down is necessary, 0 otherwise + */ +static int ata_eh_speed_down_needed(struct ata_device *dev) +{ + const u64 interval = 15LLU * 60 * HZ; + static const int err_limits[3] = { -1, 3, 10 }; + struct speed_down_needed_arg arg; + struct ata_ering_entry *ent; + int err_cat; + u64 j64; + + ent = ata_ering_top(&dev->ering); + if (!ent) + return 0; + + err_cat = ata_eh_categorize_ering_entry(ent); + if (err_cat == 0) + return 0; + + memset(&arg, 0, sizeof(arg)); + + j64 = get_jiffies_64(); + if (j64 >= interval) + arg.since = j64 - interval; + else + arg.since = 0; + + ata_ering_map(&dev->ering, speed_down_needed_cb, &arg); + + return arg.nr_errors[err_cat] > err_limits[err_cat]; +} + +/** + * ata_eh_speed_down - record error and speed down if necessary + * @dev: Failed device + * @is_io: Did the device fail during normal IO? + * @err_mask: err_mask of the error + * + * Record error and examine error history to determine whether + * adjusting transmission speed is necessary. It also sets + * transmission limits appropriately if such adjustment is + * necessary. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, -errno otherwise + */ +static int ata_eh_speed_down(struct ata_device *dev, int is_io, + unsigned int err_mask) +{ + if (!err_mask) + return 0; + + /* record error and determine whether speed down is necessary */ + ata_ering_record(&dev->ering, is_io, err_mask); + + if (!ata_eh_speed_down_needed(dev)) + return 0; + + /* speed down SATA link speed if possible */ + if (sata_down_spd_limit(dev->ap) == 0) + return ATA_EH_HARDRESET; + + /* lower transfer mode */ + if (ata_down_xfermask_limit(dev, 0) == 0) + return ATA_EH_SOFTRESET; + + ata_dev_printk(dev, KERN_ERR, + "speed down requested but no transfer mode left\n"); + return 0; +} + +/** + * ata_eh_autopsy - analyze error and determine recovery action + * @ap: ATA port to perform autopsy on + * + * Analyze why @ap failed and determine which recovery action is + * needed. This function also sets more detailed AC_ERR_* values + * and fills sense data for ATAPI CHECK SENSE. + * + * LOCKING: + * Kernel thread context (may sleep). + */ +static void ata_eh_autopsy(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + unsigned int action = ehc->i.action; + struct ata_device *failed_dev = NULL; + unsigned int all_err_mask = 0; + int tag, is_io = 0; + u32 serror; + int rc; + + DPRINTK("ENTER\n"); + + /* obtain and analyze SError */ + rc = sata_scr_read(ap, SCR_ERROR, &serror); + if (rc == 0) { + ehc->i.serror |= serror; + ata_eh_analyze_serror(ap); + } else if (rc != -EOPNOTSUPP) + action |= ATA_EH_HARDRESET; + + /* any real error trumps AC_ERR_OTHER */ + if (ehc->i.err_mask & ~AC_ERR_OTHER) + ehc->i.err_mask &= ~AC_ERR_OTHER; + + all_err_mask |= ehc->i.err_mask; + + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag); + + if (!(qc->flags & ATA_QCFLAG_FAILED)) + continue; + + /* inherit upper level err_mask */ + qc->err_mask |= ehc->i.err_mask; + + if (qc->err_mask & AC_ERR_TIMEOUT) + action |= ATA_EH_SOFTRESET; + + /* analyze TF */ + action |= ata_eh_analyze_tf(qc, &qc->result_tf); + + /* DEV errors are probably spurious in case of ATA_BUS error */ + if (qc->err_mask & AC_ERR_ATA_BUS) + qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA | + AC_ERR_INVALID); + + /* any real error trumps unknown error */ + if (qc->err_mask & ~AC_ERR_OTHER) + qc->err_mask &= ~AC_ERR_OTHER; + + /* SENSE_VALID trumps dev/unknown error and revalidation */ + if (qc->flags & ATA_QCFLAG_SENSE_VALID) { + qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER); + action &= ~ATA_EH_REVALIDATE; + } + + /* accumulate error info */ + failed_dev = qc->dev; + all_err_mask |= qc->err_mask; + if (qc->flags & ATA_QCFLAG_IO) + is_io = 1; + } + + /* speed down iff command was in progress */ + if (failed_dev) + action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask); + + if (all_err_mask) + action |= ATA_EH_REVALIDATE; + + ehc->i.dev = failed_dev; + ehc->i.action = action; + + DPRINTK("EXIT\n"); +} + +/** + * ata_eh_report - report error handling to user + * @ap: ATA port EH is going on + * + * Report EH to user. + * + * LOCKING: + * None. + */ +static void ata_eh_report(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + const char *frozen, *desc; + int tag, nr_failed = 0; + + desc = NULL; + if (ehc->i.desc[0] != '\0') + desc = ehc->i.desc; + + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag); + + if (!(qc->flags & ATA_QCFLAG_FAILED)) + continue; + if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask) + continue; + + nr_failed++; + } + + if (!nr_failed && !ehc->i.err_mask) + return; + + frozen = ""; + if (ap->flags & ATA_FLAG_FROZEN) + frozen = " frozen"; + + if (ehc->i.dev) { + ata_dev_printk(ehc->i.dev, KERN_ERR, + "exception Emask 0x%x SErr 0x%x action 0x%x%s\n", + ehc->i.err_mask, ehc->i.serror, ehc->i.action, + frozen); + if (desc) + ata_dev_printk(ehc->i.dev, KERN_ERR, "(%s)\n", desc); + } else { + ata_port_printk(ap, KERN_ERR, + "exception Emask 0x%x SErr 0x%x action 0x%x%s\n", + ehc->i.err_mask, ehc->i.serror, ehc->i.action, + frozen); + if (desc) + ata_port_printk(ap, KERN_ERR, "(%s)\n", desc); + } + + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag); + + if (!(qc->flags & ATA_QCFLAG_FAILED) || !qc->err_mask) + continue; + + ata_dev_printk(qc->dev, KERN_ERR, "tag %d cmd 0x%x " + "Emask 0x%x stat 0x%x err 0x%x (%s)\n", + qc->tag, qc->tf.command, qc->err_mask, + qc->result_tf.command, qc->result_tf.feature, + ata_err_string(qc->err_mask)); + } +} + +static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset, + ata_reset_fn_t hardreset, ata_postreset_fn_t postreset) +{ + struct ata_eh_context *ehc = &ap->eh_context; + unsigned int classes[ATA_MAX_DEVICES]; + int tries = ATA_EH_RESET_TRIES; + ata_reset_fn_t reset; + int rc; + + if (softreset && (!hardreset || (!sata_set_spd_needed(ap) && + !(ehc->i.action & ATA_EH_HARDRESET)))) + reset = softreset; + else + reset = hardreset; + + retry: + ata_port_printk(ap, KERN_INFO, "%s resetting port\n", + reset == softreset ? "soft" : "hard"); + + /* reset */ + ata_eh_about_to_do(ap, ATA_EH_RESET_MASK); + ehc->i.flags |= ATA_EHI_DID_RESET; + + rc = ata_do_reset(ap, reset, classes); + + if (rc && --tries) { + ata_port_printk(ap, KERN_WARNING, + "%sreset failed, retrying in 5 secs\n", + reset == softreset ? "soft" : "hard"); + ssleep(5); + + if (reset == hardreset) + sata_down_spd_limit(ap); + if (hardreset) + reset = hardreset; + goto retry; + } + + if (rc == 0) { + if (postreset) + postreset(ap, classes); + + /* reset successful, schedule revalidation */ + ehc->i.dev = NULL; + ehc->i.action &= ~ATA_EH_RESET_MASK; + ehc->i.action |= ATA_EH_REVALIDATE; + } + + return rc; +} + +static int ata_eh_revalidate(struct ata_port *ap, + struct ata_device **r_failed_dev) +{ + struct ata_eh_context *ehc = &ap->eh_context; + struct ata_device *dev; + int i, rc = 0; + + DPRINTK("ENTER\n"); + + for (i = 0; i < ATA_MAX_DEVICES; i++) { + dev = &ap->device[i]; + + if (ehc->i.action & ATA_EH_REVALIDATE && ata_dev_enabled(dev) && + (!ehc->i.dev || ehc->i.dev == dev)) { + if (ata_port_offline(ap)) { + rc = -EIO; + break; + } + + ata_eh_about_to_do(ap, ATA_EH_REVALIDATE); + rc = ata_dev_revalidate(dev, + ehc->i.flags & ATA_EHI_DID_RESET); + if (rc) + break; + + ehc->i.action &= ~ATA_EH_REVALIDATE; + } + } + + if (rc) + *r_failed_dev = dev; + + DPRINTK("EXIT\n"); + return rc; +} + +static int ata_port_nr_enabled(struct ata_port *ap) +{ + int i, cnt = 0; + + for (i = 0; i < ATA_MAX_DEVICES; i++) + if (ata_dev_enabled(&ap->device[i])) + cnt++; + return cnt; +} + +/** + * ata_eh_recover - recover host port after error + * @ap: host port to recover + * @softreset: softreset method (can be NULL) + * @hardreset: hardreset method (can be NULL) + * @postreset: postreset method (can be NULL) + * + * This is the alpha and omega, eum and yang, heart and soul of + * libata exception handling. On entry, actions required to + * recover each devices are recorded in eh_context. This + * function executes all the operations with appropriate retrials + * and fallbacks to resurrect failed devices. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, -errno on failure. + */ +static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset, + ata_reset_fn_t hardreset, + ata_postreset_fn_t postreset) +{ + struct ata_eh_context *ehc = &ap->eh_context; + struct ata_device *dev; + int down_xfermask, i, rc; + + DPRINTK("ENTER\n"); + + /* prep for recovery */ + for (i = 0; i < ATA_MAX_DEVICES; i++) { + dev = &ap->device[i]; + + ehc->tries[dev->devno] = ATA_EH_DEV_TRIES; + } + + retry: + down_xfermask = 0; + rc = 0; + + /* skip EH if possible. */ + if (!ata_port_nr_enabled(ap) && !(ap->flags & ATA_FLAG_FROZEN)) + ehc->i.action = 0; + + /* reset */ + if (ehc->i.action & ATA_EH_RESET_MASK) { + ata_eh_freeze_port(ap); + + rc = ata_eh_reset(ap, softreset, hardreset, postreset); + if (rc) { + ata_port_printk(ap, KERN_ERR, + "reset failed, giving up\n"); + goto out; + } + + ata_eh_thaw_port(ap); + } + + /* revalidate existing devices */ + rc = ata_eh_revalidate(ap, &dev); + if (rc) + goto dev_fail; + + /* configure transfer mode if the port has been reset */ + if (ehc->i.flags & ATA_EHI_DID_RESET) { + rc = ata_set_mode(ap, &dev); + if (rc) { + down_xfermask = 1; + goto dev_fail; + } + } + + goto out; + + dev_fail: + switch (rc) { + case -ENODEV: + case -EINVAL: + ehc->tries[dev->devno] = 0; + break; + case -EIO: + sata_down_spd_limit(ap); + default: + ehc->tries[dev->devno]--; + if (down_xfermask && + ata_down_xfermask_limit(dev, ehc->tries[dev->devno] == 1)) + ehc->tries[dev->devno] = 0; + } + + /* disable device if it has used up all its chances */ + if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) + ata_dev_disable(dev); + + /* soft didn't work? be haaaaard */ + if (ehc->i.flags & ATA_EHI_DID_RESET) + ehc->i.action |= ATA_EH_HARDRESET; + else + ehc->i.action |= ATA_EH_SOFTRESET; + + if (ata_port_nr_enabled(ap)) { + ata_port_printk(ap, KERN_WARNING, "failed to recover some " + "devices, retrying in 5 secs\n"); + ssleep(5); + } else { + /* no device left, repeat fast */ + msleep(500); + } + + goto retry; + + out: + if (rc) { + for (i = 0; i < ATA_MAX_DEVICES; i++) + ata_dev_disable(&ap->device[i]); + } + + DPRINTK("EXIT, rc=%d\n", rc); + return rc; +} + +/** + * ata_eh_finish - finish up EH + * @ap: host port to finish EH for + * + * Recovery is complete. Clean up EH states and retry or finish + * failed qcs. + * + * LOCKING: + * None. + */ +static void ata_eh_finish(struct ata_port *ap) +{ + int tag; + + /* retry or finish qcs */ + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag); + + if (!(qc->flags & ATA_QCFLAG_FAILED)) + continue; + + if (qc->err_mask) { + /* FIXME: Once EH migration is complete, + * generate sense data in this function, + * considering both err_mask and tf. + */ + if (qc->err_mask & AC_ERR_INVALID) + ata_eh_qc_complete(qc); + else + ata_eh_qc_retry(qc); + } else { + if (qc->flags & ATA_QCFLAG_SENSE_VALID) { + ata_eh_qc_complete(qc); + } else { + /* feed zero TF to sense generation */ + memset(&qc->result_tf, 0, sizeof(qc->result_tf)); + ata_eh_qc_retry(qc); + } + } + } +} + +/** + * ata_do_eh - do standard error handling + * @ap: host port to handle error for + * @softreset: softreset method (can be NULL) + * @hardreset: hardreset method (can be NULL) + * @postreset: postreset method (can be NULL) + * + * Perform standard error handling sequence. + * + * LOCKING: + * Kernel thread context (may sleep). + */ +void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset, + ata_reset_fn_t hardreset, ata_postreset_fn_t postreset) +{ + ata_eh_autopsy(ap); + ata_eh_report(ap); + ata_eh_recover(ap, softreset, hardreset, postreset); + ata_eh_finish(ap); +} |