1 files changed, 529 insertions, 225 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index f1e129b7c972..93d18a74c401 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -41,6 +41,7 @@
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
 #include <scsi/scsi_transport.h>
 #include <linux/libata.h>
 #include <linux/hdreg.h>
@@ -51,10 +52,14 @@
 #define SECTOR_SIZE     512
 
 typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc, const u8 *scsicmd);
-static struct ata_device *
-ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev);
-static void ata_scsi_error(struct Scsi_Host *host);
-enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
+
+static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
+                                        const struct scsi_device *scsidev);
+static struct ata_device * ata_scsi_find_dev(struct ata_port *ap,
+                                            const struct scsi_device *scsidev);
+static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
+                              unsigned int id, unsigned int lun);
+
 
 #define RW_RECOVERY_MPAGE 0x1
 #define RW_RECOVERY_MPAGE_LEN 12
@@ -102,6 +107,7 @@ static const u8 def_control_mpage[CONTROL_MPAGE_LEN] = {
 struct scsi_transport_template ata_scsi_transport_template = {
         .eh_strategy_handler    = ata_scsi_error,
         .eh_timed_out           = ata_scsi_timed_out,
+        .user_scan              = ata_scsi_user_scan,
 };
 
 
@@ -304,7 +310,6 @@ int ata_scsi_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg)
 
 /**
  *      ata_scsi_qc_new - acquire new ata_queued_cmd reference
- *      @ap: ATA port to which the new command is attached
  *      @dev: ATA device to which the new command is attached
  *      @cmd: SCSI command that originated this ATA command
  *      @done: SCSI command completion function
@@ -323,14 +328,13 @@ int ata_scsi_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg)
  *      RETURNS:
  *      Command allocated, or %NULL if none available.
  */
-struct ata_queued_cmd *ata_scsi_qc_new(struct ata_port *ap,
-                                       struct ata_device *dev,
+struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
                                        struct scsi_cmnd *cmd,
                                        void (*done)(struct scsi_cmnd *))
 {
         struct ata_queued_cmd *qc;
 
-        qc = ata_qc_new_init(ap, dev);
+        qc = ata_qc_new_init(dev);
         if (qc) {
                 qc->scsicmd = cmd;
                 qc->scsidone = done;
@@ -397,18 +401,18 @@ void ata_dump_status(unsigned id, struct ata_taskfile *tf)
 
 int ata_scsi_device_resume(struct scsi_device *sdev)
 {
-        struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
-        struct ata_device *dev = &ap->device[sdev->id];
+        struct ata_port *ap = ata_shost_to_port(sdev->host);
+        struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
 
-        return ata_device_resume(ap, dev);
+        return ata_device_resume(dev);
 }
 
 int ata_scsi_device_suspend(struct scsi_device *sdev, pm_message_t state)
 {
-        struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
-        struct ata_device *dev = &ap->device[sdev->id];
+        struct ata_port *ap = ata_shost_to_port(sdev->host);
+        struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
 
-        return ata_device_suspend(ap, dev, state);
+        return ata_device_suspend(dev, state);
 }
 
 /**
@@ -419,6 +423,7 @@ int ata_scsi_device_suspend(struct scsi_device *sdev, pm_message_t state)
  *      @sk: the sense key we'll fill out
  *      @asc: the additional sense code we'll fill out
  *      @ascq: the additional sense code qualifier we'll fill out
+ *      @verbose: be verbose
  *
  *      Converts an ATA error into a SCSI error.  Fill out pointers to
  *      SK, ASC, and ASCQ bytes for later use in fixed or descriptor
@@ -428,7 +433,7 @@ int ata_scsi_device_suspend(struct scsi_device *sdev, pm_message_t state)
  *      spin_lock_irqsave(host_set lock)
  */
 void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
-                        u8 *ascq)
+                        u8 *ascq, int verbose)
 {
         int i;
 
@@ -493,8 +498,9 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
                         }
                 }
                 /* No immediate match */
-                printk(KERN_WARNING "ata%u: no sense translation for "
-                       "error 0x%02x\n", id, drv_err);
+                if (verbose)
+                        printk(KERN_WARNING "ata%u: no sense translation for "
+                               "error 0x%02x\n", id, drv_err);
         }
 
         /* Fall back to interpreting status bits */
@@ -507,8 +513,9 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
                 }
         }
         /* No error?  Undecoded? */
-        printk(KERN_WARNING "ata%u: no sense translation for status: 0x%02x\n",
-               id, drv_stat);
+        if (verbose)
+                printk(KERN_WARNING "ata%u: no sense translation for "
+                       "status: 0x%02x\n", id, drv_stat);
 
         /* We need a sensible error return here, which is tricky, and one
            that won't cause people to do things like return a disk wrongly */
@@ -517,9 +524,10 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
         *ascq = 0x00;
 
  translate_done:
-        printk(KERN_ERR "ata%u: translated ATA stat/err 0x%02x/%02x to "
-               "SCSI SK/ASC/ASCQ 0x%x/%02x/%02x\n", id, drv_stat, drv_err,
-               *sk, *asc, *ascq);
+        if (verbose)
+                printk(KERN_ERR "ata%u: translated ATA stat/err 0x%02x/%02x "
+                       "to SCSI SK/ASC/ASCQ 0x%x/%02x/%02x\n",
+                       id, drv_stat, drv_err, *sk, *asc, *ascq);
         return;
 }
 
@@ -539,27 +547,23 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
 void ata_gen_ata_desc_sense(struct ata_queued_cmd *qc)
 {
         struct scsi_cmnd *cmd = qc->scsicmd;
-        struct ata_taskfile *tf = &qc->tf;
+        struct ata_taskfile *tf = &qc->result_tf;
         unsigned char *sb = cmd->sense_buffer;
         unsigned char *desc = sb + 8;
+        int verbose = qc->ap->ops->error_handler == NULL;
 
         memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
 
         cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 
         /*
-         * Read the controller registers.
-         */
-        WARN_ON(qc->ap->ops->tf_read == NULL);
-        qc->ap->ops->tf_read(qc->ap, tf);
-
-        /*
          * Use ata_to_sense_error() to map status register bits
          * onto sense key, asc & ascq.
          */
-        if (tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
+        if (qc->err_mask ||
+            tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
                 ata_to_sense_error(qc->ap->id, tf->command, tf->feature,
-                                   &sb[1], &sb[2], &sb[3]);
+                                   &sb[1], &sb[2], &sb[3], verbose);
                 sb[1] &= 0x0f;
         }
 
@@ -615,26 +619,22 @@ void ata_gen_ata_desc_sense(struct ata_queued_cmd *qc)
 void ata_gen_fixed_sense(struct ata_queued_cmd *qc)
 {
         struct scsi_cmnd *cmd = qc->scsicmd;
-        struct ata_taskfile *tf = &qc->tf;
+        struct ata_taskfile *tf = &qc->result_tf;
         unsigned char *sb = cmd->sense_buffer;
+        int verbose = qc->ap->ops->error_handler == NULL;
 
         memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
 
         cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 
         /*
-         * Read the controller registers.
-         */
-        WARN_ON(qc->ap->ops->tf_read == NULL);
-        qc->ap->ops->tf_read(qc->ap, tf);
-
-        /*
          * Use ata_to_sense_error() to map status register bits
          * onto sense key, asc & ascq.
          */
-        if (tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
+        if (qc->err_mask ||
+            tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
                 ata_to_sense_error(qc->ap->id, tf->command, tf->feature,
-                                   &sb[2], &sb[12], &sb[13]);
+                                   &sb[2], &sb[12], &sb[13], verbose);
                 sb[2] &= 0x0f;
         }
 
@@ -677,7 +677,7 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
          */
         max_sectors = ATA_MAX_SECTORS;
         if (dev->flags & ATA_DFLAG_LBA48)
-                max_sectors = 2048;
+                max_sectors = ATA_MAX_SECTORS_LBA48;
         if (dev->max_sectors)
                 max_sectors = dev->max_sectors;
 
@@ -692,6 +692,14 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
                 request_queue_t *q = sdev->request_queue;
                 blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
         }
+
+        if (dev->flags & ATA_DFLAG_NCQ) {
+                int depth;
+
+                depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
+                depth = min(ATA_MAX_QUEUE - 1, depth);
+                scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
+        }
 }
 
 /**
@@ -708,152 +716,88 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
 
 int ata_scsi_slave_config(struct scsi_device *sdev)
 {
+        struct ata_port *ap = ata_shost_to_port(sdev->host);
+        struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
+
         ata_scsi_sdev_config(sdev);
 
         blk_queue_max_phys_segments(sdev->request_queue, LIBATA_MAX_PRD);
 
-        if (sdev->id < ATA_MAX_DEVICES) {
-                struct ata_port *ap;
-                struct ata_device *dev;
-
-                ap = (struct ata_port *) &sdev->host->hostdata[0];
-                dev = &ap->device[sdev->id];
-
+        if (dev)
                 ata_scsi_dev_config(sdev, dev);
-        }
 
         return 0;       /* scsi layer doesn't check return value, sigh */
 }
 
 /**
- *      ata_scsi_timed_out - SCSI layer time out callback
- *      @cmd: timed out SCSI command
+ *      ata_scsi_slave_destroy - SCSI device is about to be destroyed
+ *      @sdev: SCSI device to be destroyed
  *
- *      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.
+ *      @sdev is about to be destroyed for hot/warm unplugging.  If
+ *      this unplugging was initiated by libata as indicated by NULL
+ *      dev->sdev, this function doesn't have to do anything.
+ *      Otherwise, SCSI layer initiated warm-unplug is in progress.
+ *      Clear dev->sdev, schedule the device for ATA detach and invoke
+ *      EH.
  *
  *      LOCKING:
- *      Called from timer context
- *
- *      RETURNS:
- *      EH_HANDLED or EH_NOT_HANDLED
+ *      Defined by SCSI layer.  We don't really care.
  */
-enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
+void ata_scsi_slave_destroy(struct scsi_device *sdev)
 {
-        struct Scsi_Host *host = cmd->device->host;
-        struct ata_port *ap = (struct ata_port *) &host->hostdata[0];
+        struct ata_port *ap = ata_shost_to_port(sdev->host);
         unsigned long flags;
-        struct ata_queued_cmd *qc;
-        enum scsi_eh_timer_return ret = EH_HANDLED;
+        struct ata_device *dev;
 
-        DPRINTK("ENTER\n");
+        if (!ap->ops->error_handler)
+                return;
 
-        spin_lock_irqsave(&ap->host_set->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_lock_irqsave(ap->lock, flags);
+        dev = __ata_scsi_find_dev(ap, sdev);
+        if (dev && dev->sdev) {
+                /* SCSI device already in CANCEL state, no need to offline it */
+                dev->sdev = NULL;
+                dev->flags |= ATA_DFLAG_DETACH;
+                ata_port_schedule_eh(ap);
         }
-        spin_unlock_irqrestore(&ap->host_set->lock, flags);
-
-        DPRINTK("EXIT, ret=%d\n", ret);
-        return ret;
+        spin_unlock_irqrestore(ap->lock, flags);
 }
 
 /**
- *      ata_scsi_error - SCSI layer error handler callback
- *      @host: SCSI host on which error occurred
+ *      ata_scsi_change_queue_depth - SCSI callback for queue depth config
+ *      @sdev: SCSI device to configure queue depth for
+ *      @queue_depth: new queue depth
  *
- *      Handles SCSI-layer-thrown error events.
+ *      This is libata standard hostt->change_queue_depth callback.
+ *      SCSI will call into this callback when user tries to set queue
+ *      depth via sysfs.
  *
  *      LOCKING:
- *      Inherited from SCSI layer (none, can sleep)
+ *      SCSI layer (we don't care)
+ *
+ *      RETURNS:
+ *      Newly configured queue depth.
  */
-
-static void ata_scsi_error(struct Scsi_Host *host)
+int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 {
-        struct ata_port *ap;
-        unsigned long flags;
-
-        DPRINTK("ENTER\n");
-
-        ap = (struct ata_port *) &host->hostdata[0];
-
-        spin_lock_irqsave(&ap->host_set->lock, flags);
-        WARN_ON(ap->flags & ATA_FLAG_IN_EH);
-        ap->flags |= ATA_FLAG_IN_EH;
-        WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL);
-        spin_unlock_irqrestore(&ap->host_set->lock, flags);
-
-        ata_port_flush_task(ap);
-
-        ap->ops->eng_timeout(ap);
-
-        WARN_ON(host->host_failed || !list_empty(&host->eh_cmd_q));
-
-        scsi_eh_flush_done_q(&ap->eh_done_q);
-
-        spin_lock_irqsave(&ap->host_set->lock, flags);
-        ap->flags &= ~ATA_FLAG_IN_EH;
-        spin_unlock_irqrestore(&ap->host_set->lock, flags);
-
-        DPRINTK("EXIT\n");
-}
-
-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;
+        struct ata_port *ap = ata_shost_to_port(sdev->host);
+        struct ata_device *dev;
+        int max_depth;
 
-        spin_lock_irqsave(&ap->host_set->lock, flags);
-        qc->scsidone = ata_eh_scsidone;
-        __ata_qc_complete(qc);
-        WARN_ON(ata_tag_valid(qc->tag));
-        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+        if (queue_depth < 1)
+                return sdev->queue_depth;
 
-        scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
-}
+        dev = ata_scsi_find_dev(ap, sdev);
+        if (!dev || !ata_dev_enabled(dev))
+                return sdev->queue_depth;
 
-/**
- *      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);
-}
+        max_depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
+        max_depth = min(ATA_MAX_QUEUE - 1, max_depth);
+        if (queue_depth > max_depth)
+                queue_depth = max_depth;
 
-/**
- *      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.
- *      This function might need to adjust scmd->retries for commands
- *      which get retried due to unrelated NCQ failures.
- */
-void ata_eh_qc_retry(struct ata_queued_cmd *qc)
-{
-        __ata_eh_qc_complete(qc);
+        scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, queue_depth);
+        return queue_depth;
 }
 
 /**
@@ -891,7 +835,7 @@ static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc,
                 tf->nsect = 1;  /* 1 sector, lba=0 */
 
                 if (qc->dev->flags & ATA_DFLAG_LBA) {
-                        qc->tf.flags |= ATA_TFLAG_LBA;
+                        tf->flags |= ATA_TFLAG_LBA;
 
                         tf->lbah = 0x0;
                         tf->lbam = 0x0;
@@ -1195,6 +1139,7 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicm
         u64 block;
         u32 n_block;
 
+        qc->flags |= ATA_QCFLAG_IO;
         tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
 
         if (scsicmd[0] == WRITE_10 || scsicmd[0] == WRITE_6 ||
@@ -1241,7 +1186,36 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicm
                  */
                 goto nothing_to_do;
 
-        if (dev->flags & ATA_DFLAG_LBA) {
+        if ((dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ) {
+                /* yay, NCQ */
+                if (!lba_48_ok(block, n_block))
+                        goto out_of_range;
+
+                tf->protocol = ATA_PROT_NCQ;
+                tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
+
+                if (tf->flags & ATA_TFLAG_WRITE)
+                        tf->command = ATA_CMD_FPDMA_WRITE;
+                else
+                        tf->command = ATA_CMD_FPDMA_READ;
+
+                qc->nsect = n_block;
+
+                tf->nsect = qc->tag << 3;
+                tf->hob_feature = (n_block >> 8) & 0xff;
+                tf->feature = n_block & 0xff;
+
+                tf->hob_lbah = (block >> 40) & 0xff;
+                tf->hob_lbam = (block >> 32) & 0xff;
+                tf->hob_lbal = (block >> 24) & 0xff;
+                tf->lbah = (block >> 16) & 0xff;
+                tf->lbam = (block >> 8) & 0xff;
+                tf->lbal = block & 0xff;
+
+                tf->device = 1 << 6;
+                if (tf->flags & ATA_TFLAG_FUA)
+                        tf->device |= 1 << 7;
+        } else if (dev->flags & ATA_DFLAG_LBA) {
                 tf->flags |= ATA_TFLAG_LBA;
 
                 if (lba_28_ok(block, n_block)) {
@@ -1332,6 +1306,17 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
         u8 *cdb = cmd->cmnd;
         int need_sense = (qc->err_mask != 0);
 
+        /* We snoop the SET_FEATURES - Write Cache ON/OFF command, and
+         * schedule EH_REVALIDATE operation to update the IDENTIFY DEVICE
+         * cache
+         */
+        if (!need_sense && (qc->tf.command == ATA_CMD_SET_FEATURES) &&
+            ((qc->tf.feature == SETFEATURES_WC_ON) ||
+             (qc->tf.feature == SETFEATURES_WC_OFF))) {
+                qc->ap->eh_info.action |= ATA_EH_REVALIDATE;
+                ata_port_schedule_eh(qc->ap);
+        }
+
         /* For ATA pass thru (SAT) commands, generate a sense block if
          * user mandated it or if there's an error.  Note that if we
          * generate because the user forced us to, a check condition
@@ -1356,10 +1341,8 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
                 }
         }
 
-        if (need_sense) {
-                /* The ata_gen_..._sense routines fill in tf */
-                ata_dump_status(qc->ap->id, &qc->tf);
-        }
+        if (need_sense && !qc->ap->ops->error_handler)
+                ata_dump_status(qc->ap->id, &qc->result_tf);
 
         qc->scsidone(cmd);
 
@@ -1367,8 +1350,40 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 }
 
 /**
+ *      ata_scmd_need_defer - Check whether we need to defer scmd
+ *      @dev: ATA device to which the command is addressed
+ *      @is_io: Is the command IO (and thus possibly NCQ)?
+ *
+ *      NCQ and non-NCQ commands cannot run together.  As upper layer
+ *      only knows the queue depth, we are responsible for maintaining
+ *      exclusion.  This function checks whether a new command can be
+ *      issued to @dev.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      1 if deferring is needed, 0 otherwise.
+ */
+static int ata_scmd_need_defer(struct ata_device *dev, int is_io)
+{
+        struct ata_port *ap = dev->ap;
+
+        if (!(dev->flags & ATA_DFLAG_NCQ))
+                return 0;
+
+        if (is_io) {
+                if (!ata_tag_valid(ap->active_tag))
+                        return 0;
+        } else {
+                if (!ata_tag_valid(ap->active_tag) && !ap->sactive)
+                        return 0;
+        }
+        return 1;
+}
+
+/**
  *      ata_scsi_translate - Translate then issue SCSI command to ATA device
- *      @ap: ATA port to which the command is addressed
  *      @dev: ATA device to which the command is addressed
  *      @cmd: SCSI command to execute
  *      @done: SCSI command completion function
@@ -1389,19 +1404,25 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
  *
  *      LOCKING:
  *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      0 on success, SCSI_ML_QUEUE_DEVICE_BUSY if the command
+ *      needs to be deferred.
  */
-
-static void ata_scsi_translate(struct ata_port *ap, struct ata_device *dev,
-                              struct scsi_cmnd *cmd,
+static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
                               void (*done)(struct scsi_cmnd *),
                               ata_xlat_func_t xlat_func)
 {
         struct ata_queued_cmd *qc;
         u8 *scsicmd = cmd->cmnd;
+        int is_io = xlat_func == ata_scsi_rw_xlat;
 
         VPRINTK("ENTER\n");
 
-        qc = ata_scsi_qc_new(ap, dev, cmd, done);
+        if (unlikely(ata_scmd_need_defer(dev, is_io)))
+                goto defer;
+
+        qc = ata_scsi_qc_new(dev, cmd, done);
         if (!qc)
                 goto err_mem;
 
@@ -1409,8 +1430,8 @@ static void ata_scsi_translate(struct ata_port *ap, struct ata_device *dev,
         if (cmd->sc_data_direction == DMA_FROM_DEVICE ||
             cmd->sc_data_direction == DMA_TO_DEVICE) {
                 if (unlikely(cmd->request_bufflen < 1)) {
-                        printk(KERN_WARNING "ata%u(%u): WARNING: zero len r/w req\n",
-                               ap->id, dev->devno);
+                        ata_dev_printk(dev, KERN_WARNING,
+                                       "WARNING: zero len r/w req\n");
                         goto err_did;
                 }
 
@@ -1432,13 +1453,13 @@ static void ata_scsi_translate(struct ata_port *ap, struct ata_device *dev,
         ata_qc_issue(qc);
 
         VPRINTK("EXIT\n");
-        return;
+        return 0;
 
 early_finish:
         ata_qc_free(qc);
         done(cmd);
         DPRINTK("EXIT - early finish (good or error)\n");
-        return;
+        return 0;
 
 err_did:
         ata_qc_free(qc);
@@ -1446,7 +1467,11 @@ err_mem:
         cmd->result = (DID_ERROR << 16);
         done(cmd);
         DPRINTK("EXIT - internal\n");
-        return;
+        return 0;
+
+defer:
+        DPRINTK("EXIT - defer\n");
+        return SCSI_MLQUEUE_DEVICE_BUSY;
 }
 
 /**
@@ -1944,7 +1969,7 @@ unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf,
                 return 0;
 
         dpofua = 0;
-        if (ata_dev_supports_fua(args->id) && dev->flags & ATA_DFLAG_LBA48 &&
+        if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
             (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
                 dpofua = 1 << 4;
 
@@ -2137,13 +2162,14 @@ void ata_scsi_badcmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *), u8
 
 static void atapi_sense_complete(struct ata_queued_cmd *qc)
 {
-        if (qc->err_mask && ((qc->err_mask & AC_ERR_DEV) == 0))
+        if (qc->err_mask && ((qc->err_mask & AC_ERR_DEV) == 0)) {
                 /* FIXME: not quite right; we don't want the
                  * translation of taskfile registers into
                  * a sense descriptors, since that's only
                  * correct for ATA, not ATAPI
                  */
                 ata_gen_ata_desc_sense(qc);
+        }
 
         qc->scsidone(qc->scsicmd);
         ata_qc_free(qc);
@@ -2207,21 +2233,38 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
 
         VPRINTK("ENTER, err_mask 0x%X\n", err_mask);
 
+        /* handle completion from new EH */
+        if (unlikely(qc->ap->ops->error_handler &&
+                     (err_mask || qc->flags & ATA_QCFLAG_SENSE_VALID))) {
+
+                if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) {
+                        /* FIXME: not quite right; we don't want the
+                         * translation of taskfile registers into a
+                         * sense descriptors, since that's only
+                         * correct for ATA, not ATAPI
+                         */
+                        ata_gen_ata_desc_sense(qc);
+                }
+
+                qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
+                qc->scsidone(cmd);
+                ata_qc_free(qc);
+                return;
+        }
+
+        /* successful completion or old EH failure path */
         if (unlikely(err_mask & AC_ERR_DEV)) {
                 cmd->result = SAM_STAT_CHECK_CONDITION;
                 atapi_request_sense(qc);
                 return;
-        }
-
-        else if (unlikely(err_mask))
+        } else if (unlikely(err_mask)) {
                 /* FIXME: not quite right; we don't want the
                  * translation of taskfile registers into
                  * a sense descriptors, since that's only
                  * correct for ATA, not ATAPI
                  */
                 ata_gen_ata_desc_sense(qc);
-
-        else {
+        } else {
                 u8 *scsicmd = cmd->cmnd;
 
                 if ((scsicmd[0] == INQUIRY) && ((scsicmd[1] & 0x03) == 0)) {
@@ -2303,11 +2346,9 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
                 qc->tf.protocol = ATA_PROT_ATAPI_DMA;
                 qc->tf.feature |= ATAPI_PKT_DMA;
 
-#ifdef ATAPI_ENABLE_DMADIR
-                /* some SATA bridges need us to indicate data xfer direction */
-                if (cmd->sc_data_direction != DMA_TO_DEVICE)
+                if (atapi_dmadir && (cmd->sc_data_direction != DMA_TO_DEVICE))
+                        /* some SATA bridges need us to indicate data xfer direction */
                         qc->tf.feature |= ATAPI_DMADIR;
-#endif
         }
 
         qc->nbytes = cmd->request_bufflen;
@@ -2315,6 +2356,53 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
         return 0;
 }
 
+static struct ata_device * ata_find_dev(struct ata_port *ap, int id)
+{
+        if (likely(id < ATA_MAX_DEVICES))
+                return &ap->device[id];
+        return NULL;
+}
+
+static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
+                                        const struct scsi_device *scsidev)
+{
+        /* skip commands not addressed to targets we simulate */
+        if (unlikely(scsidev->channel || scsidev->lun))
+                return NULL;
+
+        return ata_find_dev(ap, scsidev->id);
+}
+
+/**
+ *      ata_scsi_dev_enabled - determine if device is enabled
+ *      @dev: ATA device
+ *
+ *      Determine if commands should be sent to the specified device.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      0 if commands are not allowed / 1 if commands are allowed
+ */
+
+static int ata_scsi_dev_enabled(struct ata_device *dev)
+{
+        if (unlikely(!ata_dev_enabled(dev)))
+                return 0;
+
+        if (!atapi_enabled || (dev->ap->flags & ATA_FLAG_NO_ATAPI)) {
+                if (unlikely(dev->class == ATA_DEV_ATAPI)) {
+                        ata_dev_printk(dev, KERN_WARNING,
+                                       "WARNING: ATAPI is %s, device ignored.\n",
+                                       atapi_enabled ? "not supported with this driver" : "disabled");
+                        return 0;
+                }
+        }
+
+        return 1;
+}
+
 /**
  *      ata_scsi_find_dev - lookup ata_device from scsi_cmnd
  *      @ap: ATA port to which the device is attached
@@ -2331,33 +2419,14 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
  *      RETURNS:
  *      Associated ATA device, or %NULL if not found.
  */
-
 static struct ata_device *
 ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
 {
-        struct ata_device *dev;
+        struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
 
-        /* skip commands not addressed to targets we simulate */
-        if (likely(scsidev->id < ATA_MAX_DEVICES))
-                dev = &ap->device[scsidev->id];
-        else
+        if (unlikely(!dev || !ata_scsi_dev_enabled(dev)))
                 return NULL;
 
-        if (unlikely((scsidev->channel != 0) ||
-                     (scsidev->lun != 0)))
-                return NULL;
-
-        if (unlikely(!ata_dev_present(dev)))
-                return NULL;
-
-        if (!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) {
-                if (unlikely(dev->class == ATA_DEV_ATAPI)) {
-                        printk(KERN_WARNING "ata%u(%u): WARNING: ATAPI is %s, device ignored.\n",
-                               ap->id, dev->devno, atapi_enabled ? "not supported with this driver" : "disabled");
-                        return NULL;
-                }
-        }
-
         return dev;
 }
 
@@ -2414,10 +2483,15 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 {
         struct ata_taskfile *tf = &(qc->tf);
         struct scsi_cmnd *cmd = qc->scsicmd;
+        struct ata_device *dev = qc->dev;
 
         if ((tf->protocol = ata_scsi_map_proto(scsicmd[1])) == ATA_PROT_UNKNOWN)
                 goto invalid_fld;
 
+        /* We may not issue DMA commands if no DMA mode is set */
+        if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0)
+                goto invalid_fld;
+
         if (scsicmd[1] & 0xe0)
                 /* PIO multi not supported yet */
                 goto invalid_fld;
@@ -2502,6 +2576,9 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
          */
         qc->nsect = cmd->request_bufflen / ATA_SECT_SIZE;
 
+        /* request result TF */
+        qc->flags |= ATA_QCFLAG_RESULT_TF;
+
         return 0;
 
  invalid_fld:
@@ -2578,19 +2655,24 @@ static inline void ata_scsi_dump_cdb(struct ata_port *ap,
 #endif
 }
 
-static inline void __ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
-                                       struct ata_port *ap, struct ata_device *dev)
+static inline int __ata_scsi_queuecmd(struct scsi_cmnd *cmd,
+                                      void (*done)(struct scsi_cmnd *),
+                                      struct ata_device *dev)
 {
+        int rc = 0;
+
         if (dev->class == ATA_DEV_ATA) {
                 ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
                                                               cmd->cmnd[0]);
 
                 if (xlat_func)
-                        ata_scsi_translate(ap, dev, cmd, done, xlat_func);
+                        rc = ata_scsi_translate(dev, cmd, done, xlat_func);
                 else
-                        ata_scsi_simulate(ap, dev, cmd, done);
+                        ata_scsi_simulate(dev, cmd, done);
         } else
-                ata_scsi_translate(ap, dev, cmd, done, atapi_xlat);
+                rc = ata_scsi_translate(dev, cmd, done, atapi_xlat);
+
+        return rc;
 }
 
 /**
@@ -2609,39 +2691,39 @@ static inline void __ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struc
  *      Releases scsi-layer-held lock, and obtains host_set lock.
  *
  *      RETURNS:
- *      Zero.
+ *      Return value from __ata_scsi_queuecmd() if @cmd can be queued,
+ *      0 otherwise.
  */
-
 int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
         struct ata_port *ap;
         struct ata_device *dev;
         struct scsi_device *scsidev = cmd->device;
         struct Scsi_Host *shost = scsidev->host;
+        int rc = 0;
 
-        ap = (struct ata_port *) &shost->hostdata[0];
+        ap = ata_shost_to_port(shost);
 
         spin_unlock(shost->host_lock);
-        spin_lock(&ap->host_set->lock);
+        spin_lock(ap->lock);
 
         ata_scsi_dump_cdb(ap, cmd);
 
         dev = ata_scsi_find_dev(ap, scsidev);
         if (likely(dev))
-                __ata_scsi_queuecmd(cmd, done, ap, dev);
+                rc = __ata_scsi_queuecmd(cmd, done, dev);
         else {
                 cmd->result = (DID_BAD_TARGET << 16);
                 done(cmd);
         }
 
-        spin_unlock(&ap->host_set->lock);
+        spin_unlock(ap->lock);
         spin_lock(shost->host_lock);
-        return 0;
+        return rc;
 }
 
 /**
  *      ata_scsi_simulate - simulate SCSI command on ATA device
- *      @ap: port the device is connected to
  *      @dev: the target device
  *      @cmd: SCSI command being sent to device.
  *      @done: SCSI command completion function.
@@ -2653,14 +2735,12 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
  *      spin_lock_irqsave(host_set lock)
  */
 
-void ata_scsi_simulate(struct ata_port *ap, struct ata_device *dev,
-                      struct scsi_cmnd *cmd,
+void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd,
                       void (*done)(struct scsi_cmnd *))
 {
         struct ata_scsi_args args;
         const u8 *scsicmd = cmd->cmnd;
 
-        args.ap = ap;
         args.dev = dev;
         args.id = dev->id;
         args.cmd = cmd;
@@ -2732,17 +2812,241 @@ void ata_scsi_simulate(struct ata_port *ap, struct ata_device *dev,
 
 void ata_scsi_scan_host(struct ata_port *ap)
 {
-        struct ata_device *dev;
         unsigned int i;
 
-        if (ap->flags & ATA_FLAG_PORT_DISABLED)
+        if (ap->flags & ATA_FLAG_DISABLED)
                 return;
 
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                dev = &ap->device[i];
+                struct ata_device *dev = &ap->device[i];
+                struct scsi_device *sdev;
 
-                if (ata_dev_present(dev))
-                        scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0);
+                if (!ata_dev_enabled(dev) || dev->sdev)
+                        continue;
+
+                sdev = __scsi_add_device(ap->host, 0, i, 0, NULL);
+                if (!IS_ERR(sdev)) {
+                        dev->sdev = sdev;
+                        scsi_device_put(sdev);
+                }
+        }
+}
+
+/**
+ *      ata_scsi_offline_dev - offline attached SCSI device
+ *      @dev: ATA device to offline attached SCSI device for
+ *
+ *      This function is called from ata_eh_hotplug() and responsible
+ *      for taking the SCSI device attached to @dev offline.  This
+ *      function is called with host_set lock which protects dev->sdev
+ *      against clearing.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      1 if attached SCSI device exists, 0 otherwise.
+ */
+int ata_scsi_offline_dev(struct ata_device *dev)
+{
+        if (dev->sdev) {
+                scsi_device_set_state(dev->sdev, SDEV_OFFLINE);
+                return 1;
         }
+        return 0;
 }
 
+/**
+ *      ata_scsi_remove_dev - remove attached SCSI device
+ *      @dev: ATA device to remove attached SCSI device for
+ *
+ *      This function is called from ata_eh_scsi_hotplug() and
+ *      responsible for removing the SCSI device attached to @dev.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ */
+static void ata_scsi_remove_dev(struct ata_device *dev)
+{
+        struct ata_port *ap = dev->ap;
+        struct scsi_device *sdev;
+        unsigned long flags;
+
+        /* Alas, we need to grab scan_mutex to ensure SCSI device
+         * state doesn't change underneath us and thus
+         * scsi_device_get() always succeeds.  The mutex locking can
+         * be removed if there is __scsi_device_get() interface which
+         * increments reference counts regardless of device state.
+         */
+        mutex_lock(&ap->host->scan_mutex);
+        spin_lock_irqsave(ap->lock, flags);
+
+        /* clearing dev->sdev is protected by host_set lock */
+        sdev = dev->sdev;
+        dev->sdev = NULL;
+
+        if (sdev) {
+                /* If user initiated unplug races with us, sdev can go
+                 * away underneath us after the host_set lock and
+                 * scan_mutex are released.  Hold onto it.
+                 */
+                if (scsi_device_get(sdev) == 0) {
+                        /* The following ensures the attached sdev is
+                         * offline on return from ata_scsi_offline_dev()
+                         * regardless it wins or loses the race
+                         * against this function.
+                         */
+                        scsi_device_set_state(sdev, SDEV_OFFLINE);
+                } else {
+                        WARN_ON(1);
+                        sdev = NULL;
+                }
+        }
+
+        spin_unlock_irqrestore(ap->lock, flags);
+        mutex_unlock(&ap->host->scan_mutex);
+
+        if (sdev) {
+                ata_dev_printk(dev, KERN_INFO, "detaching (SCSI %s)\n",
+                               sdev->sdev_gendev.bus_id);
+
+                scsi_remove_device(sdev);
+                scsi_device_put(sdev);
+        }
+}
+
+/**
+ *      ata_scsi_hotplug - SCSI part of hotplug
+ *      @data: Pointer to ATA port to perform SCSI hotplug on
+ *
+ *      Perform SCSI part of hotplug.  It's executed from a separate
+ *      workqueue after EH completes.  This is necessary because SCSI
+ *      hot plugging requires working EH and hot unplugging is
+ *      synchronized with hot plugging with a mutex.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ */
+void ata_scsi_hotplug(void *data)
+{
+        struct ata_port *ap = data;
+        int i;
+
+        if (ap->flags & ATA_FLAG_UNLOADING) {
+                DPRINTK("ENTER/EXIT - unloading\n");
+                return;
+        }
+
+        DPRINTK("ENTER\n");
+
+        /* unplug detached devices */
+        for (i = 0; i < ATA_MAX_DEVICES; i++) {
+                struct ata_device *dev = &ap->device[i];
+                unsigned long flags;
+
+                if (!(dev->flags & ATA_DFLAG_DETACHED))
+                        continue;
+
+                spin_lock_irqsave(ap->lock, flags);
+                dev->flags &= ~ATA_DFLAG_DETACHED;
+                spin_unlock_irqrestore(ap->lock, flags);
+
+                ata_scsi_remove_dev(dev);
+        }
+
+        /* scan for new ones */
+        ata_scsi_scan_host(ap);
+
+        /* If we scanned while EH was in progress, scan would have
+         * failed silently.  Requeue if there are enabled but
+         * unattached devices.
+         */
+        for (i = 0; i < ATA_MAX_DEVICES; i++) {
+                struct ata_device *dev = &ap->device[i];
+                if (ata_dev_enabled(dev) && !dev->sdev) {
+                        queue_delayed_work(ata_aux_wq, &ap->hotplug_task, HZ);
+                        break;
+                }
+        }
+
+        DPRINTK("EXIT\n");
+}
+
+/**
+ *      ata_scsi_user_scan - indication for user-initiated bus scan
+ *      @shost: SCSI host to scan
+ *      @channel: Channel to scan
+ *      @id: ID to scan
+ *      @lun: LUN to scan
+ *
+ *      This function is called when user explicitly requests bus
+ *      scan.  Set probe pending flag and invoke EH.
+ *
+ *      LOCKING:
+ *      SCSI layer (we don't care)
+ *
+ *      RETURNS:
+ *      Zero.
+ */
+static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
+                              unsigned int id, unsigned int lun)
+{
+        struct ata_port *ap = ata_shost_to_port(shost);
+        unsigned long flags;
+        int rc = 0;
+
+        if (!ap->ops->error_handler)
+                return -EOPNOTSUPP;
+
+        if ((channel != SCAN_WILD_CARD && channel != 0) ||
+            (lun != SCAN_WILD_CARD && lun != 0))
+                return -EINVAL;
+
+        spin_lock_irqsave(ap->lock, flags);
+
+        if (id == SCAN_WILD_CARD) {
+                ap->eh_info.probe_mask |= (1 << ATA_MAX_DEVICES) - 1;
+                ap->eh_info.action |= ATA_EH_SOFTRESET;
+        } else {
+                struct ata_device *dev = ata_find_dev(ap, id);
+
+                if (dev) {
+                        ap->eh_info.probe_mask |= 1 << dev->devno;
+                        ap->eh_info.action |= ATA_EH_SOFTRESET;
+                } else
+                        rc = -EINVAL;
+        }
+
+        if (rc == 0)
+                ata_port_schedule_eh(ap);
+
+        spin_unlock_irqrestore(ap->lock, flags);
+
+        return rc;
+}
+
+/**
+ *      ata_scsi_dev_rescan - initiate scsi_rescan_device()
+ *      @data: Pointer to ATA port to perform scsi_rescan_device()
+ *
+ *      After ATA pass thru (SAT) commands are executed successfully,
+ *      libata need to propagate the changes to SCSI layer.  This
+ *      function must be executed from ata_aux_wq such that sdev
+ *      attach/detach don't race with rescan.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ */
+void ata_scsi_dev_rescan(void *data)
+{
+        struct ata_port *ap = data;
+        struct ata_device *dev;
+        unsigned int i;
+
+        for (i = 0; i < ATA_MAX_DEVICES; i++) {
+                dev = &ap->device[i];
+
+                if (ata_dev_enabled(dev) && dev->sdev)
+                        scsi_rescan_device(&(dev->sdev->sdev_gendev));
+        }
+}