8 files changed, 206 insertions, 5 deletions

diff --git a/drivers/ide/Makefile b/drivers/ide/Makefile
index 0c30adb115c8..ceaf779054ea 100644
--- a/drivers/ide/Makefile
+++ b/drivers/ide/Makefile
@@ -5,7 +5,7 @@
 EXTRA_CFLAGS                            += -Idrivers/ide
 
 ide-core-y += ide.o ide-ioctls.o ide-io.o ide-iops.o ide-lib.o ide-probe.o \
-              ide-taskfile.o ide-pio-blacklist.o
+              ide-taskfile.o ide-park.o ide-pio-blacklist.o
 
 # core IDE code
 ide-core-$(CONFIG_IDE_TIMINGS)          += ide-timings.o
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index e205f46c3c7a..77c6eaeacefa 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -672,7 +672,32 @@ EXPORT_SYMBOL_GPL(ide_devset_execute);
 
 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
 {
-        switch (rq->cmd[0]) {
+        u8 cmd = rq->cmd[0];
+
+        if (cmd == REQ_PARK_HEADS || cmd == REQ_UNPARK_HEADS) {
+                ide_task_t task;
+                struct ide_taskfile *tf = &task.tf;
+
+                memset(&task, 0, sizeof(task));
+                if (cmd == REQ_PARK_HEADS) {
+                        drive->sleep = *(unsigned long *)rq->special;
+                        drive->dev_flags |= IDE_DFLAG_SLEEPING;
+                        tf->command = ATA_CMD_IDLEIMMEDIATE;
+                        tf->feature = 0x44;
+                        tf->lbal = 0x4c;
+                        tf->lbam = 0x4e;
+                        tf->lbah = 0x55;
+                        task.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER;
+                } else          /* cmd == REQ_UNPARK_HEADS */
+                        tf->command = ATA_CMD_CHK_POWER;
+
+                task.tf_flags |= IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
+                task.rq = rq;
+                drive->hwif->data_phase = task.data_phase = TASKFILE_NO_DATA;
+                return do_rw_taskfile(drive, &task);
+        }
+
+        switch (cmd) {
         case REQ_DEVSET_EXEC:
         {
                 int err, (*setfunc)(ide_drive_t *, int) = rq->special;
@@ -1008,7 +1033,7 @@ static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
                 }
                 hwgroup->hwif = hwif;
                 hwgroup->drive = drive;
-                drive->dev_flags &= ~IDE_DFLAG_SLEEPING;
+                drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
                 drive->service_start = jiffies;
 
                 if (blk_queue_plugged(drive->queue)) {
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 91182ebed468..b762deb2dacb 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -1020,6 +1020,7 @@ static void ide_disk_pre_reset(ide_drive_t *drive)
         drive->special.b.recalibrate  = legacy;
 
         drive->mult_count = 0;
+        drive->dev_flags &= ~IDE_DFLAG_PARKED;
 
         if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0 &&
             (drive->dev_flags & IDE_DFLAG_USING_DMA) == 0)
@@ -1079,12 +1080,13 @@ static void pre_reset(ide_drive_t *drive)
 static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)
 {
         unsigned int unit;
-        unsigned long flags;
+        unsigned long flags, timeout;
         ide_hwif_t *hwif;
         ide_hwgroup_t *hwgroup;
         struct ide_io_ports *io_ports;
         const struct ide_tp_ops *tp_ops;
         const struct ide_port_ops *port_ops;
+        DEFINE_WAIT(wait);
 
         spin_lock_irqsave(&ide_lock, flags);
         hwif = HWIF(drive);
@@ -1111,6 +1113,31 @@ static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)
                 return ide_started;
         }
 
+        /* We must not disturb devices in the IDE_DFLAG_PARKED state. */
+        do {
+                unsigned long now;
+
+                prepare_to_wait(&ide_park_wq, &wait, TASK_UNINTERRUPTIBLE);
+                timeout = jiffies;
+                for (unit = 0; unit < MAX_DRIVES; unit++) {
+                        ide_drive_t *tdrive = &hwif->drives[unit];
+
+                        if (tdrive->dev_flags & IDE_DFLAG_PRESENT &&
+                            tdrive->dev_flags & IDE_DFLAG_PARKED &&
+                            time_after(tdrive->sleep, timeout))
+                                timeout = tdrive->sleep;
+                }
+
+                now = jiffies;
+                if (time_before_eq(timeout, now))
+                        break;
+
+                spin_unlock_irqrestore(&ide_lock, flags);
+                timeout = schedule_timeout_uninterruptible(timeout - now);
+                spin_lock_irqsave(&ide_lock, flags);
+        } while (timeout);
+        finish_wait(&ide_park_wq, &wait);
+
         /*
          * First, reset any device state data we were maintaining
          * for any of the drives on this interface.
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
new file mode 100644
index 000000000000..03b00e57e93f
--- /dev/null
+++ b/drivers/ide/ide-park.c
@@ -0,0 +1,121 @@
+#include <linux/kernel.h>
+#include <linux/ide.h>
+#include <linux/jiffies.h>
+#include <linux/blkdev.h>
+
+DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
+
+static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
+{
+        struct request_queue *q = drive->queue;
+        struct request *rq;
+        int rc;
+
+        timeout += jiffies;
+        spin_lock_irq(&ide_lock);
+        if (drive->dev_flags & IDE_DFLAG_PARKED) {
+                ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
+                int reset_timer;
+
+                reset_timer = time_before(timeout, drive->sleep);
+                drive->sleep = timeout;
+                wake_up_all(&ide_park_wq);
+                if (reset_timer && hwgroup->sleeping &&
+                    del_timer(&hwgroup->timer)) {
+                        hwgroup->sleeping = 0;
+                        hwgroup->busy = 0;
+                        blk_start_queueing(q);
+                }
+                spin_unlock_irq(&ide_lock);
+                return;
+        }
+        spin_unlock_irq(&ide_lock);
+
+        rq = blk_get_request(q, READ, __GFP_WAIT);
+        rq->cmd[0] = REQ_PARK_HEADS;
+        rq->cmd_len = 1;
+        rq->cmd_type = REQ_TYPE_SPECIAL;
+        rq->special = &timeout;
+        rc = blk_execute_rq(q, NULL, rq, 1);
+        blk_put_request(rq);
+        if (rc)
+                goto out;
+
+        /*
+         * Make sure that *some* command is sent to the drive after the
+         * timeout has expired, so power management will be reenabled.
+         */
+        rq = blk_get_request(q, READ, GFP_NOWAIT);
+        if (unlikely(!rq))
+                goto out;
+
+        rq->cmd[0] = REQ_UNPARK_HEADS;
+        rq->cmd_len = 1;
+        rq->cmd_type = REQ_TYPE_SPECIAL;
+        elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
+
+out:
+        return;
+}
+
+ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
+                      char *buf)
+{
+        ide_drive_t *drive = to_ide_device(dev);
+        unsigned long now;
+        unsigned int msecs;
+
+        if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
+                return -EOPNOTSUPP;
+
+        spin_lock_irq(&ide_lock);
+        now = jiffies;
+        if (drive->dev_flags & IDE_DFLAG_PARKED &&
+            time_after(drive->sleep, now))
+                msecs = jiffies_to_msecs(drive->sleep - now);
+        else
+                msecs = 0;
+        spin_unlock_irq(&ide_lock);
+
+        return snprintf(buf, 20, "%u\n", msecs);
+}
+
+ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
+                       const char *buf, size_t len)
+{
+#define MAX_PARK_TIMEOUT 30000
+        ide_drive_t *drive = to_ide_device(dev);
+        long int input;
+        int rc;
+
+        rc = strict_strtol(buf, 10, &input);
+        if (rc || input < -2)
+                return -EINVAL;
+        if (input > MAX_PARK_TIMEOUT) {
+                input = MAX_PARK_TIMEOUT;
+                rc = -EOVERFLOW;
+        }
+
+        mutex_lock(&ide_setting_mtx);
+        if (input >= 0) {
+                if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
+                        rc = -EOPNOTSUPP;
+                else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
+                        issue_park_cmd(drive, msecs_to_jiffies(input));
+        } else {
+                if (drive->media == ide_disk)
+                        switch (input) {
+                        case -1:
+                                drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
+                                break;
+                        case -2:
+                                drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
+                                break;
+                        }
+                else
+                        rc = -EOPNOTSUPP;
+        }
+        mutex_unlock(&ide_setting_mtx);
+
+        return rc ? rc : len;
+}
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index de8edd306c79..f27baa5f140e 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -208,6 +208,8 @@ static inline void do_identify (ide_drive_t *drive, u8 cmd)
                 drive->ready_stat = 0;
                 if (ata_id_cdb_intr(id))
                         drive->atapi_flags |= IDE_AFLAG_DRQ_INTERRUPT;
+                /* we don't do head unloading on ATAPI devices */
+                drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
                 return;
         }
 
@@ -223,6 +225,9 @@ static inline void do_identify (ide_drive_t *drive, u8 cmd)
 
         drive->media = ide_disk;
 
+        if (!ata_id_has_unload(drive->id))
+                drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
+
         printk(KERN_CONT "%s DISK drive\n", is_cfa ? "CFA" : "ATA");
 
         return;
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index a4c2d91179b3..bf4fb9d8d176 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -152,7 +152,16 @@ static ide_startstop_t task_no_data_intr(ide_drive_t *drive)
 
         if (!custom)
                 ide_end_drive_cmd(drive, stat, ide_read_error(drive));
-        else if (tf->command == ATA_CMD_SET_MULTI)
+        else if (tf->command == ATA_CMD_IDLEIMMEDIATE) {
+                hwif->tp_ops->tf_read(drive, task);
+                if (tf->lbal != 0xc4) {
+                        printk(KERN_ERR "%s: head unload failed!\n",
+                               drive->name);
+                        ide_tf_dump(drive->name, tf);
+                } else
+                        drive->dev_flags |= IDE_DFLAG_PARKED;
+                ide_end_drive_cmd(drive, stat, ide_read_error(drive));
+        } else if (tf->command == ATA_CMD_SET_MULTI)
                 drive->mult_count = drive->mult_req;
 
         return ide_stopped;
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 083783e851d1..04f8f13cb9d7 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -587,6 +587,7 @@ static struct device_attribute ide_dev_attrs[] = {
         __ATTR_RO(model),
         __ATTR_RO(firmware),
         __ATTR(serial, 0400, serial_show, NULL),
+        __ATTR(unload_heads, 0644, ide_park_show, ide_park_store),
         __ATTR_NULL
 };
 
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 8247b286838d..c47e371554c1 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -156,6 +156,8 @@ enum {
  */
 #define REQ_DRIVE_RESET         0x20
 #define REQ_DEVSET_EXEC         0x21
+#define REQ_PARK_HEADS          0x22
+#define REQ_UNPARK_HEADS        0x23
 
 /*
  * Check for an interrupt and acknowledge the interrupt status
@@ -573,6 +575,10 @@ enum {
         /* retrying in PIO */
         IDE_DFLAG_DMA_PIO_RETRY         = (1 << 25),
         IDE_DFLAG_LBA                   = (1 << 26),
+        /* don't unload heads */
+        IDE_DFLAG_NO_UNLOAD             = (1 << 27),
+        /* heads unloaded, please don't reset port */
+        IDE_DFLAG_PARKED                = (1 << 28)
 };
 
 struct ide_drive_s {
@@ -1207,6 +1213,13 @@ int ide_check_atapi_device(ide_drive_t *, const char *);
 
 void ide_init_pc(struct ide_atapi_pc *);
 
+/* Disk head parking */
+extern wait_queue_head_t ide_park_wq;
+ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
+                      char *buf);
+ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
+                       const char *buf, size_t len);
+
 /*
  * Special requests for ide-tape block device strategy routine.
  *