diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index cf4e702..2377a32 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -34,14 +34,6 @@
 	u8	tf[REGS_PER_GTF];	/* regs. 0x1f1 - 0x1f7 */
 } __packed;
 
-/*
- *	Helper - belongs in the PCI layer somewhere eventually
- */
-static int is_pci_dev(struct device *dev)
-{
-	return (dev->bus == &pci_bus_type);
-}
-
 static void ata_acpi_clear_gtf(struct ata_device *dev)
 {
 	kfree(dev->gtf_cache);
@@ -49,47 +41,18 @@
 }
 
 /**
- * ata_ap_acpi_handle - provide the acpi_handle for an ata_port
- * @ap: the acpi_handle returned will correspond to this port
- *
- * Returns the acpi_handle for the ACPI namespace object corresponding to
- * the ata_port passed into the function, or NULL if no such object exists
- */
-acpi_handle ata_ap_acpi_handle(struct ata_port *ap)
-{
-	if (ap->flags & ATA_FLAG_ACPI_SATA)
-		return NULL;
-
-	return ap->scsi_host ?
-		DEVICE_ACPI_HANDLE(&ap->scsi_host->shost_gendev) : NULL;
-}
-EXPORT_SYMBOL(ata_ap_acpi_handle);
-
-/**
  * ata_dev_acpi_handle - provide the acpi_handle for an ata_device
- * @dev: the acpi_device returned will correspond to this port
+ * @dev: the acpi_handle returned will correspond to this device
  *
  * Returns the acpi_handle for the ACPI namespace object corresponding to
  * the ata_device passed into the function, or NULL if no such object exists
+ * or ACPI is disabled for this device due to consecutive errors.
  */
 acpi_handle ata_dev_acpi_handle(struct ata_device *dev)
 {
-	acpi_integer adr;
-	struct ata_port *ap = dev->link->ap;
-
-	if (libata_noacpi || dev->flags & ATA_DFLAG_ACPI_DISABLED)
-		return NULL;
-
-	if (ap->flags & ATA_FLAG_ACPI_SATA) {
-		if (!sata_pmp_attached(ap))
-			adr = SATA_ADR(ap->port_no, NO_PORT_MULT);
-		else
-			adr = SATA_ADR(ap->port_no, dev->link->pmp);
-		return acpi_get_child(DEVICE_ACPI_HANDLE(ap->host->dev), adr);
-	} else
-		return acpi_get_child(ata_ap_acpi_handle(ap), dev->devno);
+	return dev->flags & ATA_DFLAG_ACPI_DISABLED ?
+			NULL : ACPI_HANDLE(&dev->tdev);
 }
-EXPORT_SYMBOL(ata_dev_acpi_handle);
 
 /* @ap and @dev are the same as ata_acpi_handle_hotplug() */
 static void ata_acpi_detach_device(struct ata_port *ap, struct ata_device *dev)
@@ -156,10 +119,8 @@
 
 	spin_unlock_irqrestore(ap->lock, flags);
 
-	if (wait) {
+	if (wait)
 		ata_port_wait_eh(ap);
-		flush_work(&ap->hotplug_task.work);
-	}
 }
 
 static void ata_acpi_dev_notify_dock(acpi_handle handle, u32 event, void *data)
@@ -216,37 +177,55 @@
 	.uevent = ata_acpi_ap_uevent,
 };
 
-void ata_acpi_hotplug_init(struct ata_host *host)
+/* bind acpi handle to pata port */
+void ata_acpi_bind_port(struct ata_port *ap)
 {
-	int i;
+	acpi_handle host_handle = ACPI_HANDLE(ap->host->dev);
 
-	for (i = 0; i < host->n_ports; i++) {
-		struct ata_port *ap = host->ports[i];
-		acpi_handle handle;
-		struct ata_device *dev;
+	if (libata_noacpi || ap->flags & ATA_FLAG_ACPI_SATA || !host_handle)
+		return;
 
-		if (!ap)
-			continue;
+	ACPI_HANDLE_SET(&ap->tdev, acpi_get_child(host_handle, ap->port_no));
 
-		handle = ata_ap_acpi_handle(ap);
-		if (handle) {
-			/* we might be on a docking station */
-			register_hotplug_dock_device(handle,
-						     &ata_acpi_ap_dock_ops, ap,
-						     NULL, NULL);
-		}
+	if (ata_acpi_gtm(ap, &ap->__acpi_init_gtm) == 0)
+		ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;
 
-		ata_for_each_dev(dev, &ap->link, ALL) {
-			handle = ata_dev_acpi_handle(dev);
-			if (!handle)
-				continue;
+	/* we might be on a docking station */
+	register_hotplug_dock_device(ACPI_HANDLE(&ap->tdev),
+				     &ata_acpi_ap_dock_ops, ap, NULL, NULL);
+}
 
-			/* we might be on a docking station */
-			register_hotplug_dock_device(handle,
-						     &ata_acpi_dev_dock_ops,
-						     dev, NULL, NULL);
-		}
+void ata_acpi_bind_dev(struct ata_device *dev)
+{
+	struct ata_port *ap = dev->link->ap;
+	acpi_handle port_handle = ACPI_HANDLE(&ap->tdev);
+	acpi_handle host_handle = ACPI_HANDLE(ap->host->dev);
+	acpi_handle parent_handle;
+	u64 adr;
+
+	/*
+	 * For both sata/pata devices, host handle is required.
+	 * For pata device, port handle is also required.
+	 */
+	if (libata_noacpi || !host_handle ||
+			(!(ap->flags & ATA_FLAG_ACPI_SATA) && !port_handle))
+		return;
+
+	if (ap->flags & ATA_FLAG_ACPI_SATA) {
+		if (!sata_pmp_attached(ap))
+			adr = SATA_ADR(ap->port_no, NO_PORT_MULT);
+		else
+			adr = SATA_ADR(ap->port_no, dev->link->pmp);
+		parent_handle = host_handle;
+	} else {
+		adr = dev->devno;
+		parent_handle = port_handle;
 	}
+
+	ACPI_HANDLE_SET(&dev->tdev, acpi_get_child(parent_handle, adr));
+
+	register_hotplug_dock_device(ata_dev_acpi_handle(dev),
+				     &ata_acpi_dev_dock_ops, dev, NULL, NULL);
 }
 
 /**
@@ -270,18 +249,34 @@
 		struct ata_port *ap = host->ports[i];
 		const struct ata_acpi_gtm *gtm = ata_acpi_init_gtm(ap);
 
-		if (ata_ap_acpi_handle(ap) && gtm)
+		if (ACPI_HANDLE(&ap->tdev) && gtm)
 			ata_acpi_stm(ap, gtm);
 	}
 }
 
-static int __ata_acpi_gtm(struct ata_port *ap, acpi_handle handle,
-			  struct ata_acpi_gtm *gtm)
+/**
+ * ata_acpi_gtm - execute _GTM
+ * @ap: target ATA port
+ * @gtm: out parameter for _GTM result
+ *
+ * Evaluate _GTM and store the result in @gtm.
+ *
+ * LOCKING:
+ * EH context.
+ *
+ * RETURNS:
+ * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
+ */
+int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)
 {
 	struct acpi_buffer output = { .length = ACPI_ALLOCATE_BUFFER };
 	union acpi_object *out_obj;
 	acpi_status status;
 	int rc = 0;
+	acpi_handle handle = ACPI_HANDLE(&ap->tdev);
+
+	if (!handle)
+		return -EINVAL;
 
 	status = acpi_evaluate_object(handle, "_GTM", NULL, &output);
 
@@ -317,27 +312,6 @@
 	return rc;
 }
 
-/**
- * ata_acpi_gtm - execute _GTM
- * @ap: target ATA port
- * @gtm: out parameter for _GTM result
- *
- * Evaluate _GTM and store the result in @gtm.
- *
- * LOCKING:
- * EH context.
- *
- * RETURNS:
- * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
- */
-int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)
-{
-	if (ata_ap_acpi_handle(ap))
-		return __ata_acpi_gtm(ap, ata_ap_acpi_handle(ap), gtm);
-	else
-		return -EINVAL;
-}
-
 EXPORT_SYMBOL_GPL(ata_acpi_gtm);
 
 /**
@@ -374,8 +348,8 @@
 	input.count = 3;
 	input.pointer = in_params;
 
-	status = acpi_evaluate_object(ata_ap_acpi_handle(ap), "_STM", &input,
-				      NULL);
+	status = acpi_evaluate_object(ACPI_HANDLE(&ap->tdev), "_STM",
+				      &input, NULL);
 
 	if (status == AE_NOT_FOUND)
 		return -ENOENT;
@@ -850,7 +824,7 @@
 	const struct ata_acpi_gtm *gtm = ata_acpi_init_gtm(ap);
 	struct ata_device *dev;
 
-	if (ata_ap_acpi_handle(ap) && gtm) {
+	if (ACPI_HANDLE(&ap->tdev) && gtm) {
 		/* _GTM valid */
 
 		/* restore timing parameters */
@@ -894,8 +868,7 @@
 		d_max_in = ACPI_STATE_D3_HOT;
 
 out:
-	return acpi_pm_device_sleep_state(&dev->sdev->sdev_gendev,
-					  NULL, d_max_in);
+	return acpi_pm_device_sleep_state(&dev->tdev, NULL, d_max_in);
 }
 
 static void sata_acpi_set_state(struct ata_port *ap, pm_message_t state)
@@ -932,7 +905,7 @@
 	struct ata_device *dev;
 	acpi_handle port_handle;
 
-	port_handle = ata_ap_acpi_handle(ap);
+	port_handle = ACPI_HANDLE(&ap->tdev);
 	if (!port_handle)
 		return;
 
@@ -1063,109 +1036,16 @@
 	ata_acpi_clear_gtf(dev);
 }
 
-static int compat_pci_ata(struct ata_port *ap)
+void ata_scsi_acpi_bind(struct ata_device *dev)
 {
-	struct device *dev = ap->tdev.parent;
-	struct pci_dev *pdev;
-
-	if (!is_pci_dev(dev))
-		return 0;
-
-	pdev = to_pci_dev(dev);
-
-	if ((pdev->class >> 8) != PCI_CLASS_STORAGE_SATA &&
-	    (pdev->class >> 8) != PCI_CLASS_STORAGE_IDE)
-		return 0;
-
-	return 1;
+	acpi_handle handle = ata_dev_acpi_handle(dev);
+	if (handle)
+		acpi_dev_pm_add_dependent(handle, &dev->sdev->sdev_gendev);
 }
 
-static int ata_acpi_bind_host(struct ata_port *ap, acpi_handle *handle)
+void ata_scsi_acpi_unbind(struct ata_device *dev)
 {
-	if (libata_noacpi || ap->flags & ATA_FLAG_ACPI_SATA)
-		return -ENODEV;
-
-	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(ap->tdev.parent),
-			ap->port_no);
-
-	if (!*handle)
-		return -ENODEV;
-
-	if (__ata_acpi_gtm(ap, *handle, &ap->__acpi_init_gtm) == 0)
-		ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;
-
-	return 0;
-}
-
-static int ata_acpi_bind_device(struct ata_port *ap, struct scsi_device *sdev,
-				acpi_handle *handle)
-{
-	struct ata_device *ata_dev;
-
-	if (ap->flags & ATA_FLAG_ACPI_SATA) {
-		if (!sata_pmp_attached(ap))
-			ata_dev = &ap->link.device[sdev->id];
-		else
-			ata_dev = &ap->pmp_link[sdev->channel].device[sdev->id];
-	}
-	else {
-		ata_dev = &ap->link.device[sdev->id];
-	}
-
-	*handle = ata_dev_acpi_handle(ata_dev);
-
-	if (!*handle)
-		return -ENODEV;
-
-	return 0;
-}
-
-static int is_ata_port(const struct device *dev)
-{
-	return dev->type == &ata_port_type;
-}
-
-static struct ata_port *dev_to_ata_port(struct device *dev)
-{
-	while (!is_ata_port(dev)) {
-		if (!dev->parent)
-			return NULL;
-		dev = dev->parent;
-	}
-	return to_ata_port(dev);
-}
-
-static int ata_acpi_find_device(struct device *dev, acpi_handle *handle)
-{
-	struct ata_port *ap = dev_to_ata_port(dev);
-
-	if (!ap)
-		return -ENODEV;
-
-	if (!compat_pci_ata(ap))
-		return -ENODEV;
-
-	if (scsi_is_host_device(dev))
-		return ata_acpi_bind_host(ap, handle);
-	else if (scsi_is_sdev_device(dev)) {
-		struct scsi_device *sdev = to_scsi_device(dev);
-
-		return ata_acpi_bind_device(ap, sdev, handle);
-	} else
-		return -ENODEV;
-}
-
-static struct acpi_bus_type ata_acpi_bus = {
-	.name = "ATA",
-	.find_device = ata_acpi_find_device,
-};
-
-int ata_acpi_register(void)
-{
-	return scsi_register_acpi_bus_type(&ata_acpi_bus);
-}
-
-void ata_acpi_unregister(void)
-{
-	scsi_unregister_acpi_bus_type(&ata_acpi_bus);
+	acpi_handle handle = ata_dev_acpi_handle(dev);
+	if (handle)
+		acpi_dev_pm_remove_dependent(handle, &dev->sdev->sdev_gendev);
 }
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c24354d..39e78e4 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6150,8 +6150,6 @@
 	if (rc)
 		goto err_tadd;
 
-	ata_acpi_hotplug_init(host);
-
 	/* set cable, sata_spd_limit and report */
 	for (i = 0; i < host->n_ports; i++) {
 		struct ata_port *ap = host->ports[i];
@@ -6632,8 +6630,6 @@
 
 	ata_parse_force_param();
 
-	ata_acpi_register();
-
 	rc = ata_sff_init();
 	if (rc) {
 		kfree(ata_force_tbl);
@@ -6660,7 +6656,6 @@
 	ata_release_transport(ata_scsi_transport_template);
 	libata_transport_exit();
 	ata_sff_exit();
-	ata_acpi_unregister();
 	kfree(ata_force_tbl);
 }
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 83c0890..f177ad6b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -49,7 +49,6 @@
 #include <linux/hdreg.h>
 #include <linux/uaccess.h>
 #include <linux/suspend.h>
-#include <linux/pm_qos.h>
 #include <asm/unaligned.h>
 
 #include "libata.h"
@@ -3665,9 +3664,7 @@
 			if (!IS_ERR(sdev)) {
 				dev->sdev = sdev;
 				scsi_device_put(sdev);
-				if (zpodd_dev_enabled(dev))
-					dev_pm_qos_expose_flags(
-							&sdev->sdev_gendev, 0);
+				ata_scsi_acpi_bind(dev);
 			} else {
 				dev->sdev = NULL;
 			}
@@ -3755,6 +3752,8 @@
 	struct scsi_device *sdev;
 	unsigned long flags;
 
+	ata_scsi_acpi_unbind(dev);
+
 	/* 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
@@ -3764,9 +3763,6 @@
 	mutex_lock(&ap->scsi_host->scan_mutex);
 	spin_lock_irqsave(ap->lock, flags);
 
-	if (zpodd_dev_enabled(dev))
-		zpodd_exit(dev);
-
 	/* clearing dev->sdev is protected by host lock */
 	sdev = dev->sdev;
 	dev->sdev = NULL;
@@ -3816,6 +3812,9 @@
 		dev->flags &= ~ATA_DFLAG_DETACHED;
 		spin_unlock_irqrestore(ap->lock, flags);
 
+		if (zpodd_dev_enabled(dev))
+			zpodd_exit(dev);
+
 		ata_scsi_remove_dev(dev);
 	}
 }
diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
index 077a856..150a917 100644
--- a/drivers/ata/libata-transport.c
+++ b/drivers/ata/libata-transport.c
@@ -287,6 +287,7 @@
 	dev->release = ata_tport_release;
 	dev_set_name(dev, "ata%d", ap->print_id);
 	transport_setup_device(dev);
+	ata_acpi_bind_port(ap);
 	error = device_add(dev);
 	if (error) {
 		goto tport_err;
@@ -644,6 +645,7 @@
 		dev_set_name(dev, "dev%d.%d.0", ap->print_id, link->pmp);
 
 	transport_setup_device(dev);
+	ata_acpi_bind_dev(ata_dev);
 	error = device_add(dev);
 	if (error) {
 		ata_tdev_free(ata_dev);
diff --git a/drivers/ata/libata-zpodd.c b/drivers/ata/libata-zpodd.c
index cd8daf4..68f9e32 100644
--- a/drivers/ata/libata-zpodd.c
+++ b/drivers/ata/libata-zpodd.c
@@ -2,6 +2,7 @@
 #include <linux/cdrom.h>
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
+#include <linux/pm_qos.h>
 #include <scsi/scsi_device.h>
 
 #include "libata.h"
@@ -190,8 +191,8 @@
 	sdev_disable_disk_events(dev->sdev);
 
 	zpodd->powered_off = true;
-	device_set_run_wake(&dev->sdev->sdev_gendev, true);
-	acpi_pm_device_run_wake(&dev->sdev->sdev_gendev, true);
+	device_set_run_wake(&dev->tdev, true);
+	acpi_pm_device_run_wake(&dev->tdev, true);
 }
 
 /* Disable runtime wake capability if it is enabled */
@@ -200,8 +201,8 @@
 	struct zpodd *zpodd = dev->zpodd;
 
 	if (zpodd->powered_off) {
-		acpi_pm_device_run_wake(&dev->sdev->sdev_gendev, false);
-		device_set_run_wake(&dev->sdev->sdev_gendev, false);
+		acpi_pm_device_run_wake(&dev->tdev, false);
+		device_set_run_wake(&dev->tdev, false);
 	}
 }
 
@@ -262,7 +263,7 @@
 
 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
 {
-	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->sdev->sdev_gendev);
+	acpi_handle handle = ata_dev_acpi_handle(dev);
 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
 }
 
@@ -290,6 +291,7 @@
 	ata_acpi_add_pm_notifier(dev);
 	zpodd->dev = dev;
 	dev->zpodd = zpodd;
+	dev_pm_qos_expose_flags(&dev->tdev, 0);
 }
 
 void zpodd_exit(struct ata_device *dev)
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index cc8a6e8..3e9cc95 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -118,9 +118,11 @@
 extern int ata_acpi_on_devcfg(struct ata_device *dev);
 extern void ata_acpi_on_disable(struct ata_device *dev);
 extern void ata_acpi_set_state(struct ata_port *ap, pm_message_t state);
-extern int ata_acpi_register(void);
-extern void ata_acpi_unregister(void);
-extern void ata_acpi_hotplug_init(struct ata_host *host);
+extern void ata_acpi_bind_port(struct ata_port *ap);
+extern void ata_acpi_bind_dev(struct ata_device *dev);
+extern acpi_handle ata_dev_acpi_handle(struct ata_device *dev);
+extern void ata_scsi_acpi_bind(struct ata_device *dev);
+extern void ata_scsi_acpi_unbind(struct ata_device *dev);
 #else
 static inline void ata_acpi_dissociate(struct ata_host *host) { }
 static inline int ata_acpi_on_suspend(struct ata_port *ap) { return 0; }
@@ -129,9 +131,11 @@
 static inline void ata_acpi_on_disable(struct ata_device *dev) { }
 static inline void ata_acpi_set_state(struct ata_port *ap,
 				      pm_message_t state) { }
-static inline int ata_acpi_register(void) { return 0; }
-static inline void ata_acpi_unregister(void) { }
-static inline void ata_acpi_hotplug_init(struct ata_host *host) {}
+static inline void ata_acpi_bind_port(struct ata_port *ap) {}
+static inline void ata_acpi_bind_dev(struct ata_device *dev) {}
+static inline acpi_handle ata_dev_acpi_handle(struct ata_device *dev) { return NULL; }
+static inline void ata_scsi_acpi_bind(struct ata_device *dev) {}
+static inline void ata_scsi_acpi_unbind(struct ata_device *dev) {}
 #endif
 
 /* libata-scsi.c */
diff --git a/drivers/ata/pata_acpi.c b/drivers/ata/pata_acpi.c
index 09723b7..73212c9 100644
--- a/drivers/ata/pata_acpi.c
+++ b/drivers/ata/pata_acpi.c
@@ -39,7 +39,7 @@
 {
 	struct ata_port *ap = link->ap;
 	struct pata_acpi *acpi = ap->private_data;
-	if (ata_ap_acpi_handle(ap) == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
+	if (ACPI_HANDLE(&ap->tdev) == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
 		return -ENODEV;
 
 	return ata_sff_prereset(link, deadline);
@@ -195,7 +195,7 @@
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 	struct pata_acpi *acpi;
 
-	if (ata_ap_acpi_handle(ap) == NULL)
+	if (ACPI_HANDLE(&ap->tdev) == NULL)
 		return -ENODEV;
 
 	acpi = ap->private_data = devm_kzalloc(&pdev->dev, sizeof(struct pata_acpi), GFP_KERNEL);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 124392f..f0ddc7d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -68,28 +68,6 @@
 
 struct kmem_cache *scsi_sdb_cache;
 
-#ifdef CONFIG_ACPI
-#include <acpi/acpi_bus.h>
-
-static bool acpi_scsi_bus_match(struct device *dev)
-{
-	return dev->bus == &scsi_bus_type;
-}
-
-int scsi_register_acpi_bus_type(struct acpi_bus_type *bus)
-{
-        bus->match = acpi_scsi_bus_match;
-        return register_acpi_bus_type(bus);
-}
-EXPORT_SYMBOL_GPL(scsi_register_acpi_bus_type);
-
-void scsi_unregister_acpi_bus_type(struct acpi_bus_type *bus)
-{
-	unregister_acpi_bus_type(bus);
-}
-EXPORT_SYMBOL_GPL(scsi_unregister_acpi_bus_type);
-#endif
-
 /*
  * When to reinvoke queueing after a resource shortage. It's 3 msecs to
  * not change behaviour from the previous unplug mechanism, experimentation
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 283d66b..3198617 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1244,8 +1244,6 @@
 int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *stm);
 unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
 				    const struct ata_acpi_gtm *gtm);
-acpi_handle ata_ap_acpi_handle(struct ata_port *ap);
-acpi_handle ata_dev_acpi_handle(struct ata_device *dev);
 int ata_acpi_cbl_80wire(struct ata_port *ap, const struct ata_acpi_gtm *gtm);
 #else
 static inline const struct ata_acpi_gtm *ata_acpi_init_gtm(struct ata_port *ap)