diff options
Diffstat (limited to 'drivers/scsi/libata-eh.c')
| -rw-r--r-- | drivers/scsi/libata-eh.c | 1918 |
1 files changed, 1918 insertions, 0 deletions
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c new file mode 100644 index 00000000000..bf5a72aca8a --- /dev/null +++ b/drivers/scsi/libata-eh.c @@ -0,0 +1,1918 @@ +/* + * libata-eh.c - libata error handling + * + * Maintained by: Jeff Garzik <jgarzik@pobox.com> + * Please ALWAYS copy linux-ide@vger.kernel.org + * on emails. + * + * Copyright 2006 Tejun Heo <htejun@gmail.com> + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, + * USA. + * + * + * libata documentation is available via 'make {ps|pdf}docs', + * as Documentation/DocBook/libata.* + * + * Hardware documentation available from http://www.t13.org/ and + * http://www.sata-io.org/ + * + */ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi_eh.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_cmnd.h> +#include "scsi_transport_api.h" + +#include <linux/libata.h> + +#include "libata.h" + +static void __ata_port_freeze(struct ata_port *ap); +static void ata_eh_finish(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; +} + +static unsigned int ata_eh_dev_action(struct ata_device *dev) +{ + struct ata_eh_context *ehc = &dev->ap->eh_context; + + return ehc->i.action | ehc->i.dev_action[dev->devno]; +} + +static void ata_eh_clear_action(struct ata_device *dev, + struct ata_eh_info *ehi, unsigned int action) +{ + int i; + + if (!dev) { + ehi->action &= ~action; + for (i = 0; i < ATA_MAX_DEVICES; i++) + ehi->dev_action[i] &= ~action; + } else { + /* doesn't make sense for port-wide EH actions */ + WARN_ON(!(action & ATA_EH_PERDEV_MASK)); + + /* break ehi->action into ehi->dev_action */ + if (ehi->action & action) { + for (i = 0; i < ATA_MAX_DEVICES; i++) + ehi->dev_action[i] |= ehi->action & action; + ehi->action &= ~action; + } + + /* turn off the specified per-dev action */ + ehi->dev_action[dev->devno] &= ~action; + } +} + +/** + * ata_scsi_timed_out - SCSI layer time out callback + * @cmd: timed out SCSI command + * + * Handles SCSI layer timeout. We race with normal completion of + * the qc for @cmd. If the qc is already gone, we lose and let + * the scsi command finish (EH_HANDLED). Otherwise, the qc has + * timed out and EH should be invoked. Prevent ata_qc_complete() + * 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 + * + * RETURNS: + * EH_HANDLED or EH_NOT_HANDLED + */ +enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd) +{ + struct Scsi_Host *host = cmd->device->host; + struct ata_port *ap = ata_shost_to_port(host); + unsigned long flags; + struct ata_queued_cmd *qc; + 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->lock, flags); + qc = ata_qc_from_tag(ap, ap->active_tag); + if (qc) { + WARN_ON(qc->scsicmd != cmd); + qc->flags |= ATA_QCFLAG_EH_SCHEDULED; + qc->err_mask |= AC_ERR_TIMEOUT; + ret = EH_NOT_HANDLED; + } + spin_unlock_irqrestore(ap->lock, flags); + + out: + DPRINTK("EXIT, ret=%d\n", ret); + return ret; +} + +/** + * ata_scsi_error - SCSI layer error handler callback + * @host: SCSI host on which error occurred + * + * Handles SCSI-layer-thrown error events. + * + * LOCKING: + * Inherited from SCSI layer (none, can sleep) + * + * RETURNS: + * Zero. + */ +void ata_scsi_error(struct Scsi_Host *host) +{ + struct ata_port *ap = ata_shost_to_port(host); + spinlock_t *ap_lock = ap->lock; + int i, repeat_cnt = ATA_EH_MAX_REPEAT; + unsigned long flags; + + DPRINTK("ENTER\n"); + + /* synchronize with port task */ + ata_port_flush_task(ap); + + /* 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(ap_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); + } + } + + /* 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(ap_lock, flags); + } else + spin_unlock_wait(ap_lock); + + repeat: + /* invoke error handler */ + if (ap->ops->error_handler) { + /* fetch & clear EH info */ + spin_lock_irqsave(ap_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_IN_PROGRESS; + ap->flags &= ~ATA_FLAG_EH_PENDING; + + spin_unlock_irqrestore(ap_lock, flags); + + /* invoke EH. if unloading, just finish failed qcs */ + if (!(ap->flags & ATA_FLAG_UNLOADING)) + ap->ops->error_handler(ap); + else + ata_eh_finish(ap); + + /* Exception might have happend after ->error_handler + * recovered the port but before this point. Repeat + * EH in such case. + */ + spin_lock_irqsave(ap_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(ap_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 ap_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(ap_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(ap_lock, flags); + + if (ap->flags & ATA_FLAG_LOADING) { + ap->flags &= ~ATA_FLAG_LOADING; + } else { + if (ap->flags & ATA_FLAG_SCSI_HOTPLUG) + queue_work(ata_aux_wq, &ap->hotplug_task); + if (ap->flags & ATA_FLAG_RECOVERED) + ata_port_printk(ap, KERN_INFO, "EH complete\n"); + } + + ap->flags &= ~(ATA_FLAG_SCSI_HOTPLUG | ATA_FLAG_RECOVERED); + + /* tell wait_eh that we're done */ + ap->flags &= ~ATA_FLAG_EH_IN_PROGRESS; + wake_up_all(&ap->eh_wait_q); + + spin_unlock_irqrestore(ap_lock, flags); + + DPRINTK("EXIT\n"); +} + +/** + * ata_port_wait_eh - Wait for the currently pending EH to complete + * @ap: Port to wait EH for + * + * Wait until the currently pending EH is complete. + * + * LOCKING: + * Kernel thread context (may sleep). + */ +void ata_port_wait_eh(struct ata_port *ap) +{ + unsigned long flags; + DEFINE_WAIT(wait); + + retry: + spin_lock_irqsave(ap->lock, flags); + + while (ap->flags & (ATA_FLAG_EH_PENDING | ATA_FLAG_EH_IN_PROGRESS)) { + prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE); + spin_unlock_irqrestore(ap->lock, flags); + schedule(); + spin_lock_irqsave(ap->lock, flags); + } + finish_wait(&ap->eh_wait_q, &wait); + + spin_unlock_irqrestore(ap->lock, flags); + + /* make sure SCSI EH is complete */ + if (scsi_host_in_recovery(ap->host)) { + msleep(10); + goto retry; + } +} + +/** + * ata_qc_timeout - Handle timeout of queued command + * @qc: Command that timed out + * + * Some part of the kernel (currently, only the SCSI layer) + * has noticed that the active command on port @ap has not + * completed after a specified length of time. Handle this + * condition by disabling DMA (if necessary) and completing + * transactions, with error if necessary. + * + * This also handles the case of the "lost interrupt", where + * for some reason (possibly hardware bug, possibly driver bug) + * 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) + */ +static void ata_qc_timeout(struct ata_queued_cmd *qc) +{ + struct ata_port *ap = qc->ap; + u8 host_stat = 0, drv_stat; + unsigned long flags; + + DPRINTK("ENTER\n"); + + ap->hsm_task_state = HSM_ST_IDLE; + + spin_lock_irqsave(ap->lock, flags); + + switch (qc->tf.protocol) { + + case ATA_PROT_DMA: + case ATA_PROT_ATAPI_DMA: + host_stat = ap->ops->bmdma_status(ap); + + /* before we do anything else, clear DMA-Start bit */ + ap->ops->bmdma_stop(qc); + + /* fall through */ + + default: + ata_altstatus(ap); + drv_stat = ata_chk_status(ap); + + /* ack bmdma irq events */ + ap->ops->irq_clear(ap); + + 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; + break; + } + + spin_unlock_irqrestore(ap->lock, flags); + + ata_eh_qc_complete(qc); + + DPRINTK("EXIT\n"); +} + +/** + * ata_eng_timeout - Handle timeout of queued command + * @ap: Port on which timed-out command is active + * + * Some part of the kernel (currently, only the SCSI layer) + * has noticed that the active command on port @ap has not + * completed after a specified length of time. Handle this + * condition by disabling DMA (if necessary) and completing + * transactions, with error if necessary. + * + * This also handles the case of the "lost interrupt", where + * for some reason (possibly hardware bug, possibly driver bug) + * 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) + */ +void ata_eng_timeout(struct ata_port *ap) +{ + DPRINTK("ENTER\n"); + + ata_qc_timeout(ata_qc_from_tag(ap, ap->active_tag)); + + 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; + scsi_schedule_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->lock, flags); + __ata_port_freeze(ap); + spin_unlock_irqrestore(ap->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->lock, flags); + + ap->flags &= ~ATA_FLAG_FROZEN; + + if (ap->ops->thaw) + ap->ops->thaw(ap); + + spin_unlock_irqrestore(ap->lock, flags); + + DPRINTK("ata%u port thawed\n", ap->id); +} + +static void ata_eh_scsidone(struct scsi_cmnd *scmd) +{ + /* nada */ +} + +static void __ata_eh_qc_complete(struct ata_queued_cmd *qc) +{ + struct ata_port *ap = qc->ap; + struct scsi_cmnd *scmd = qc->scsicmd; + unsigned long flags; + + spin_lock_irqsave(ap->lock, flags); + qc->scsidone = ata_eh_scsidone; + __ata_qc_complete(qc); + WARN_ON(ata_tag_valid(qc->tag)); + spin_unlock_irqrestore(ap->lock, flags); + + scsi_eh_finish_cmd(scmd, &ap->eh_done_q); +} + +/** + * ata_eh_qc_complete - Complete an active ATA command from EH + * @qc: Command to complete + * + * Indicate to the mid and upper layers that an ATA command has + * completed. To be used from EH. + */ +void ata_eh_qc_complete(struct ata_queued_cmd *qc) +{ + struct scsi_cmnd *scmd = qc->scsicmd; + scmd->retries = scmd->allowed; + __ata_eh_qc_complete(qc); +} + +/** + * ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH + * @qc: Command to retry + * + * Indicate to the mid and upper layers that an ATA command + * should be retried. To be used from EH. + * + * SCSI midlayer limits the number of retries to scmd->allowed. + * scmd->retries is decremented for commands which get retried + * due to unrelated failures (qc->err_mask is zero). + */ +void ata_eh_qc_retry(struct ata_queued_cmd *qc) +{ + struct scsi_cmnd *scmd = qc->scsicmd; + if (!qc->err_mask && scmd->retries) + scmd->retries--; + __ata_eh_qc_complete(qc); +} + +/** + * ata_eh_detach_dev - detach ATA device + * @dev: ATA device to detach + * + * Detach @dev. + * + * LOCKING: + * None. + */ +static void ata_eh_detach_dev(struct ata_device *dev) +{ + struct ata_port *ap = dev->ap; + unsigned long flags; + + ata_dev_disable(dev); + + spin_lock_irqsave(ap->lock, flags); + + dev->flags &= ~ATA_DFLAG_DETACH; + + if (ata_scsi_offline_dev(dev)) { + dev->flags |= ATA_DFLAG_DETACHED; + ap->flags |= ATA_FLAG_SCSI_HOTPLUG; + } + + /* clear per-dev EH actions */ + ata_eh_clear_action(dev, &ap->eh_info, ATA_EH_PERDEV_MASK); + ata_eh_clear_action(dev, &ap->eh_context.i, ATA_EH_PERDEV_MASK); + + spin_unlock_irqrestore(ap->lock, flags); +} + +/** + * ata_eh_about_to_do - about to perform eh_action + * @ap: target ATA port + * @dev: target ATA dev for per-dev action (can be NULL) + * @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, struct ata_device *dev, + unsigned int action) +{ + unsigned long flags; + + spin_lock_irqsave(ap->lock, flags); + ata_eh_clear_action(dev, &ap->eh_info, action); + ap->flags |= ATA_FLAG_RECOVERED; + spin_unlock_irqrestore(ap->lock, flags); +} + +/** + * ata_eh_done - EH action complete + * @ap: target ATA port + * @dev: target ATA dev for per-dev action (can be NULL) + * @action: action just completed + * + * Called right after performing EH actions to clear related bits + * in @ap->eh_context. + * + * LOCKING: + * None. + */ +static void ata_eh_done(struct ata_port *ap, struct ata_device *dev, + unsigned int action) +{ + ata_eh_clear_action(dev, &ap->eh_context.i, action); +} + +/** + * 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"; +} + +/** + * ata_read_log_page - read a specific log page + * @dev: target device + * @page: page to read + * @buf: buffer to store read page + * @sectors: number of sectors to read + * + * Read log page using READ_LOG_EXT command. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, AC_ERR_* mask otherwise. + */ +static unsigned int ata_read_log_page(struct ata_device *dev, + u8 page, void *buf, unsigned int sectors) +{ + struct ata_taskfile tf; + unsigned int err_mask; + + DPRINTK("read log page - page %d\n", page); + + ata_tf_init(dev, &tf); + tf.command = ATA_CMD_READ_LOG_EXT; + tf.lbal = page; + tf.nsect = sectors; + tf.hob_nsect = sectors >> 8; + tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE; + tf.protocol = ATA_PROT_PIO; + + err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE, + buf, sectors * ATA_SECT_SIZE); + + DPRINTK("EXIT, err_mask=%x\n", err_mask); + return err_mask; +} + +/** + * ata_eh_read_log_10h - Read log page 10h for NCQ error details + * @dev: Device to read log page 10h from + * @tag: Resulting tag of the failed command + * @tf: Resulting taskfile registers of the failed command + * + * Read log page 10h to obtain NCQ error details and clear error + * condition. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, -errno otherwise. + */ +static int ata_eh_read_log_10h(struct ata_device *dev, + int *tag, struct ata_taskfile *tf) +{ + u8 *buf = dev->ap->sector_buf; + unsigned int err_mask; + u8 csum; + int i; + + err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, buf, 1); + if (err_mask) + return -EIO; + + csum = 0; + for (i = 0; i < ATA_SECT_SIZE; i++) + csum += buf[i]; + if (csum) + ata_dev_printk(dev, KERN_WARNING, + "invalid checksum 0x%x on log page 10h\n", csum); + + if (buf[0] & 0x80) + return -ENOENT; + + *tag = buf[0] & 0x1f; + + tf->command = buf[2]; + tf->feature = buf[3]; + tf->lbal = buf[4]; + tf->lbam = buf[5]; + tf->lbah = buf[6]; + tf->device = buf[7]; + tf->hob_lbal = buf[8]; + tf->hob_lbam = buf[9]; + tf->hob_lbah = buf[10]; + tf->nsect = buf[12]; + tf->hob_nsect = buf[13]; + + return 0; +} + +/** + * 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)) + ata_ehi_hotplugged(&ehc->i); + + ehc->i.err_mask |= err_mask; + ehc->i.action |= action; +} + +/** + * ata_eh_analyze_ncq_error - analyze NCQ error + * @ap: ATA port to analyze NCQ error for + * + * Read log page 10h, determine the offending qc and acquire + * error status TF. For NCQ device errors, all LLDDs have to do + * is setting AC_ERR_DEV in ehi->err_mask. This function takes + * care of the rest. + * + * LOCKING: + * Kernel thread context (may sleep). + */ +static void ata_eh_analyze_ncq_error(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + struct ata_device *dev = ap->device; + struct ata_queued_cmd *qc; + struct ata_taskfile tf; + int tag, rc; + + /* if frozen, we can't do much */ + if (ap->flags & ATA_FLAG_FROZEN) + return; + + /* is it NCQ device error? */ + if (!ap->sactive || !(ehc->i.err_mask & AC_ERR_DEV)) + return; + + /* has LLDD analyzed already? */ + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) { + qc = __ata_qc_from_tag(ap, tag); + + if (!(qc->flags & ATA_QCFLAG_FAILED)) + continue; + + if (qc->err_mask) + return; + } + + /* okay, this error is ours */ + rc = ata_eh_read_log_10h(dev, &tag, &tf); + if (rc) { + ata_port_printk(ap, KERN_ERR, "failed to read log page 10h " + "(errno=%d)\n", rc); + return; + } + + if (!(ap->sactive & (1 << tag))) { + ata_port_printk(ap, KERN_ERR, "log page 10h reported " + "inactive tag %d\n", tag); + return; + } + + /* we've got the perpetrator, condemn it */ + qc = __ata_qc_from_tag(ap, tag); + memcpy(&qc->result_tf, &tf, sizeof(tf)); + qc->err_mask |= AC_ERR_DEV; + ehc->i.err_mask &= ~AC_ERR_DEV; +} + +/** + * 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; + + /* analyze NCQ failure */ + ata_eh_analyze_ncq_error(ap); + + /* 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; + + /* 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; + } + + /* enforce default EH actions */ + if (ap->flags & ATA_FLAG_FROZEN || + all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT)) + action |= ATA_EH_SOFTRESET; + else if (all_err_mask) + action |= ATA_EH_REVALIDATE; + + /* if we have offending qcs and the associated failed device */ + if (failed_dev) { + /* speed down */ + action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask); + + /* perform per-dev EH action only on the offending device */ + ehc->i.dev_action[failed_dev->devno] |= + action & ATA_EH_PERDEV_MASK; + action &= ~ATA_EH_PERDEV_MASK; + } + + /* record autopsy result */ + 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 " + "SAct 0x%x SErr 0x%x action 0x%x%s\n", + ehc->i.err_mask, ap->sactive, 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 " + "SAct 0x%x SErr 0x%x action 0x%x%s\n", + ehc->i.err_mask, ap->sactive, 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_do_reset(struct ata_port *ap, ata_reset_fn_t reset, + unsigned int *classes) +{ + int i, rc; + + for (i = 0; i < ATA_MAX_DEVICES; i++) + classes[i] = ATA_DEV_UNKNOWN; + + rc = reset(ap, classes); + if (rc) + return rc; + + /* If any class isn't ATA_DEV_UNKNOWN, consider classification + * is complete and convert all ATA_DEV_UNKNOWN to + * ATA_DEV_NONE. + */ + for (i = 0; i < ATA_MAX_DEVICES; i++) + if (classes[i] != ATA_DEV_UNKNOWN) + break; + + if (i < ATA_MAX_DEVICES) + for (i = 0; i < ATA_MAX_DEVICES; i++) + if (classes[i] == ATA_DEV_UNKNOWN) + classes[i] = ATA_DEV_NONE; + + return 0; +} + +static int ata_eh_followup_srst_needed(int rc, int classify, + const unsigned int *classes) +{ + if (rc == -EAGAIN) + return 1; + if (rc != 0) + return 0; + if (classify && classes[0] == ATA_DEV_UNKNOWN) + return 1; + return 0; +} + +static int ata_eh_reset(struct ata_port *ap, int classify, + ata_prereset_fn_t prereset, 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 = ehc->classes; + int tries = ATA_EH_RESET_TRIES; + int verbose = !(ap->flags & ATA_FLAG_LOADING); + unsigned int action; + ata_reset_fn_t reset; + int i, did_followup_srst, rc; + + /* Determine which reset to use and record in ehc->i.action. + * prereset() may examine and modify it. + */ + action = ehc->i.action; + ehc->i.action &= ~ATA_EH_RESET_MASK; + if (softreset && (!hardreset || (!sata_set_spd_needed(ap) && + !(action & ATA_EH_HARDRESET)))) + ehc->i.action |= ATA_EH_SOFTRESET; + else + ehc->i.action |= ATA_EH_HARDRESET; + + if (prereset) { + rc = prereset(ap); + if (rc) { + ata_port_printk(ap, KERN_ERR, + "prereset failed (errno=%d)\n", rc); + return rc; + } + } + + /* prereset() might have modified ehc->i.action */ + if (ehc->i.action & ATA_EH_HARDRESET) + reset = hardreset; + else if (ehc->i.action & ATA_EH_SOFTRESET) + reset = softreset; + else { + /* prereset told us not to reset, bang classes and return */ + for (i = 0; i < ATA_MAX_DEVICES; i++) + classes[i] = ATA_DEV_NONE; + return 0; + } + + /* did prereset() screw up? if so, fix up to avoid oopsing */ + if (!reset) { + ata_port_printk(ap, KERN_ERR, "BUG: prereset() requested " + "invalid reset type\n"); + if (softreset) + reset = softreset; + else + reset = hardreset; + } + + retry: + /* shut up during boot probing */ + if (verbose) + ata_port_printk(ap, KERN_INFO, "%s resetting port\n", + reset == softreset ? "soft" : "hard"); + + /* reset */ + ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK); + ehc->i.flags |= ATA_EHI_DID_RESET; + + rc = ata_do_reset(ap, reset, classes); + + did_followup_srst = 0; + if (reset == hardreset && + ata_eh_followup_srst_needed(rc, classify, classes)) { + /* okay, let's do follow-up softreset */ + did_followup_srst = 1; + reset = softreset; + + if (!reset) { + ata_port_printk(ap, KERN_ERR, + "follow-up softreset required " + "but no softreset avaliable\n"); + return -EINVAL; + } + + ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK); + rc = ata_do_reset(ap, reset, classes); + + if (rc == 0 && classify && + classes[0] == ATA_DEV_UNKNOWN) { + ata_port_printk(ap, KERN_ERR, + "classification failed\n"); + return -EINVAL; + } + } + + if (rc && --tries) { + const char *type; + + if (reset == softreset) { + if (did_followup_srst) + type = "follow-up soft"; + else + type = "soft"; + } else + type = "hard"; + + ata_port_printk(ap, KERN_WARNING, + "%sreset failed, retrying in 5 secs\n", type); + ssleep(5); + + if (reset == hardreset) + sata_down_spd_limit(ap); + if (hardreset) + reset = hardreset; + goto retry; + } + + if (rc == 0) { + /* After the reset, the device state is PIO 0 and the + * controller state is undefined. Record the mode. + */ + for (i = 0; i < ATA_MAX_DEVICES; i++) + ap->device[i].pio_mode = XFER_PIO_0; + + if (postreset) + postreset(ap, classes); + + /* reset successful, schedule revalidation */ + ata_eh_done(ap, NULL, ATA_EH_RESET_MASK); + ehc->i.action |= ATA_EH_REVALIDATE; + } + + return rc; +} + +static int ata_eh_revalidate_and_attach(struct ata_port *ap, + struct ata_device **r_failed_dev) +{ + struct ata_eh_context *ehc = &ap->eh_context; + struct ata_device *dev; + unsigned long flags; + int i, rc = 0; + + DPRINTK("ENTER\n"); + + for (i = 0; i < ATA_MAX_DEVICES; i++) { + unsigned int action; + + dev = &ap->device[i]; + action = ata_eh_dev_action(dev); + + if (action & ATA_EH_REVALIDATE && ata_dev_enabled(dev)) { + if (ata_port_offline(ap)) { + rc = -EIO; + break; + } + + ata_eh_about_to_do(ap, dev, ATA_EH_REVALIDATE); + rc = ata_dev_revalidate(dev, + ehc->i.flags & ATA_EHI_DID_RESET); + if (rc) + break; + + ata_eh_done(ap, dev, ATA_EH_REVALIDATE); + + /* schedule the scsi_rescan_device() here */ + queue_work(ata_aux_wq, &(ap->scsi_rescan_task)); + } else if (dev->class == ATA_DEV_UNKNOWN && + ehc->tries[dev->devno] && + ata_class_enabled(ehc->classes[dev->devno])) { + dev->class = ehc->classes[dev->devno]; + + rc = ata_dev_read_id(dev, &dev->class, 1, dev->id); + if (rc == 0) + rc = ata_dev_configure(dev, 1); + + if (rc) { + dev->class = ATA_DEV_UNKNOWN; + break; + } + + spin_lock_irqsave(ap->lock, flags); + ap->flags |= ATA_FLAG_SCSI_HOTPLUG; + spin_unlock_irqrestore(ap->lock, flags); + } + } + + 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; +} + +static int ata_port_nr_vacant(struct ata_port *ap) +{ + int i, cnt = 0; + + for (i = 0; i < ATA_MAX_DEVICES; i++) + if (ap->device[i].class == ATA_DEV_UNKNOWN) + cnt++; + return cnt; +} + +static int ata_eh_skip_recovery(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + int i; + + if (ap->flags & ATA_FLAG_FROZEN || ata_port_nr_enabled(ap)) + return 0; + + /* skip if class codes for all vacant slots are ATA_DEV_NONE */ + for (i = 0; i < ATA_MAX_DEVICES; i++) { + struct ata_device *dev = &ap->device[i]; + + if (dev->class == ATA_DEV_UNKNOWN && + ehc->classes[dev->devno] != ATA_DEV_NONE) + return 0; + } + + return 1; +} + +/** + * ata_eh_recover - recover host port after error + * @ap: host port to recover + * @prereset: prereset method (can be NULL) + * @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 the port and hotplug requests are recorded in + * eh_context. This function executes all the operations with + * appropriate retrials and fallbacks to resurrect failed + * devices, detach goners and greet newcomers. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, -errno on failure. + */ +static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset, + 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; + + /* process hotplug request */ + if (dev->flags & ATA_DFLAG_DETACH) + ata_eh_detach_dev(dev); + + if (!ata_dev_enabled(dev) && + ((ehc->i.probe_mask & (1 << dev->devno)) && + !(ehc->did_probe_mask & (1 << dev->devno)))) { + ata_eh_detach_dev(dev); + ata_dev_init(dev); + ehc->did_probe_mask |= (1 << dev->devno); + ehc->i.action |= ATA_EH_SOFTRESET; + } + } + + retry: + down_xfermask = 0; + rc = 0; + + /* if UNLOADING, finish immediately */ + if (ap->flags & ATA_FLAG_UNLOADING) + goto out; + + /* skip EH if possible. */ + if (ata_eh_skip_recovery(ap)) + ehc->i.action = 0; + + for (i = 0; i < ATA_MAX_DEVICES; i++) + ehc->classes[i] = ATA_DEV_UNKNOWN; + + /* reset */ + if (ehc->i.action & ATA_EH_RESET_MASK) { + ata_eh_freeze_port(ap); + + rc = ata_eh_reset(ap, ata_port_nr_vacant(ap), prereset, + 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 and attach new ones */ + rc = ata_eh_revalidate_and_attach(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: + /* device missing, schedule probing */ + ehc->i.probe_mask |= (1 << dev->devno); + 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; + } + + if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) { + /* disable device if it has used up all its chances */ + ata_dev_disable(dev); + + /* detach if offline */ + if (ata_port_offline(ap)) + ata_eh_detach_dev(dev); + + /* probe if requested */ + if ((ehc->i.probe_mask & (1 << dev->devno)) && + !(ehc->did_probe_mask & (1 << dev->devno))) { + ata_eh_detach_dev(dev); + ata_dev_init(dev); + + ehc->tries[dev->devno] = ATA_EH_DEV_TRIES; + ehc->did_probe_mask |= (1 << dev->devno); + ehc->i.action |= ATA_EH_SOFTRESET; + } + } else { + /* 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 + * @prereset: prereset method (can be NULL) + * @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_prereset_fn_t prereset, + ata_reset_fn_t softreset, ata_reset_fn_t hardreset, + ata_postreset_fn_t postreset) +{ + if (!(ap->flags & ATA_FLAG_LOADING)) { + ata_eh_autopsy(ap); + ata_eh_report(ap); + } + + ata_eh_recover(ap, prereset, softreset, hardreset, postreset); + ata_eh_finish(ap); +} |