1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 037a561809f5..cb4e2b8d32d9 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -291,6 +291,109 @@ int ata_port_abort(struct ata_port *ap)
         return nr_aborted;
 }
 
+/**
+ *      __ata_port_freeze - freeze port
+ *      @ap: ATA port to freeze
+ *
+ *      This function is called when HSM violation or some other
+ *      condition disrupts normal operation of the port.  Frozen port
+ *      is not allowed to perform any operation until the port is
+ *      thawed, which usually follows a successful reset.
+ *
+ *      ap->ops->freeze() callback can be used for freezing the port
+ *      hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
+ *      port cannot be frozen hardware-wise, the interrupt handler
+ *      must ack and clear interrupts unconditionally while the port
+ *      is frozen.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ */
+static void __ata_port_freeze(struct ata_port *ap)
+{
+        WARN_ON(!ap->ops->error_handler);
+
+        if (ap->ops->freeze)
+                ap->ops->freeze(ap);
+
+        ap->flags |= ATA_FLAG_FROZEN;
+
+        DPRINTK("ata%u port frozen\n", ap->id);
+}
+
+/**
+ *      ata_port_freeze - abort & freeze port
+ *      @ap: ATA port to freeze
+ *
+ *      Abort and freeze @ap.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      Number of aborted commands.
+ */
+int ata_port_freeze(struct ata_port *ap)
+{
+        int nr_aborted;
+
+        WARN_ON(!ap->ops->error_handler);
+
+        nr_aborted = ata_port_abort(ap);
+        __ata_port_freeze(ap);
+
+        return nr_aborted;
+}
+
+/**
+ *      ata_eh_freeze_port - EH helper to freeze port
+ *      @ap: ATA port to freeze
+ *
+ *      Freeze @ap.
+ *
+ *      LOCKING:
+ *      None.
+ */
+void ata_eh_freeze_port(struct ata_port *ap)
+{
+        unsigned long flags;
+
+        if (!ap->ops->error_handler)
+                return;
+
+        spin_lock_irqsave(&ap->host_set->lock, flags);
+        __ata_port_freeze(ap);
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+}
+
+/**
+ *      ata_port_thaw_port - EH helper to thaw port
+ *      @ap: ATA port to thaw
+ *
+ *      Thaw frozen port @ap.
+ *
+ *      LOCKING:
+ *      None.
+ */
+void ata_eh_thaw_port(struct ata_port *ap)
+{
+        unsigned long flags;
+
+        if (!ap->ops->error_handler)
+                return;
+
+        spin_lock_irqsave(&ap->host_set->lock, flags);
+
+        ap->flags &= ~ATA_FLAG_FROZEN;
+
+        if (ap->ops->thaw)
+                ap->ops->thaw(ap);
+
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+        DPRINTK("ata%u port thawed\n", ap->id);
+}
+
 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
 {
         /* nada */