ata: acpi: rework the ata acpi bind support

Binding ACPI handle to SCSI device has several drawbacks, namely:
1 During ATA device initialization time, ACPI handle will be needed
  while SCSI devices are not created yet. So each time ACPI handle is
  needed, instead of retrieving the handle by ACPI_HANDLE macro,
  a namespace scan is performed to find the handle for the corresponding
  ATA device. This is inefficient, and also expose a restriction on
  calling path not holding any lock.
2 The binding to SCSI device tree makes code complex, while at the same
  time doesn't bring us any benefit. All ACPI handlings are still done
  in ATA module, not in SCSI.

Rework the ATA ACPI binding code to bind ACPI handle to ATA transport
devices(ATA port and ATA device). The binding needs to be done only once,
since the ATA transport devices do not go away with hotplug. And due to
this, the flush_work call in hotplug handler for ATA bay is no longer
needed.

Tested on an Intel test platform for binding and runtime power off for
ODD(ZPODD) and hard disk; on an ASUS S400C for binding and normal boot
and S3, where its SATA port node has _SDD and _GTF control methods when
configured as an AHCI controller and its PATA device node has _GTF
control method when configured as an IDE controller. SATA PMP binding
and ATA hotplug is not tested.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Tested-by: Dirk Griesbach <spamthis@freenet.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/libata-core.c

@@ -6150,8 +6150,6 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 	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 @@ static int __init ata_init(void)
 
 	ata_parse_force_param();
 
-	ata_acpi_register();
-
 	rc = ata_sff_init();
 	if (rc) {
 		kfree(ata_force_tbl);
@@ -6660,7 +6656,6 @@ static void __exit ata_exit(void)
 	ata_release_transport(ata_scsi_transport_template);
 	libata_transport_exit();
 	ata_sff_exit();
-	ata_acpi_unregister();
 	kfree(ata_force_tbl);
 }
 

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 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
 			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 @@ static void ata_scsi_remove_dev(struct ata_device *dev)
 	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 @@ static void ata_scsi_remove_dev(struct ata_device *dev)
 	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 @@ static void ata_scsi_handle_link_detach(struct ata_link *link)
 		dev->flags &= ~ATA_DFLAG_DETACHED;
 		spin_unlock_irqrestore(ap->lock, flags);
 
+		if (zpodd_dev_enabled(dev))
+			zpodd_exit(dev);
+
 		ata_scsi_remove_dev(dev);
 	}
 }

drivers/ata/libata-transport.c

@@ -287,6 +287,7 @@ int ata_tport_add(struct device *parent,
 	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 @@ static int ata_tdev_add(struct ata_device *ata_dev)
 		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);

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 @@ void zpodd_enable_run_wake(struct ata_device *dev)
 	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 @@ void zpodd_disable_run_wake(struct ata_device *dev)
 	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_add_pm_notifier(struct ata_device *dev)
 
 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 @@ void zpodd_init(struct ata_device *dev)
 	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)

drivers/ata/libata.h

@@ -118,9 +118,11 @@ extern void ata_acpi_on_resume(struct ata_port *ap);
 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 int ata_acpi_on_devcfg(struct ata_device *dev) { return 0; }
 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 */

drivers/ata/pata_acpi.c

@@ -39,7 +39,7 @@ static int pacpi_pre_reset(struct ata_link *link, unsigned long deadline)
 {
 	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 @@ static int pacpi_port_start(struct ata_port *ap)
 	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);

drivers/scsi/scsi_lib.c

@@ -68,28 +68,6 @@ static struct scsi_host_sg_pool scsi_sg_pools[] = {
 
 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

include/linux/libata.h

@@ -1244,8 +1244,6 @@ int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm);
 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)