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>

1 files changed, 79 insertions, 199 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index cf4e7020adac..2377a32861dc 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -34,14 +34,6 @@ struct ata_acpi_gtf {
         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 @@ static void ata_acpi_clear_gtf(struct ata_device *dev)
 }
 
 /**
- * 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 @@ static void ata_acpi_handle_hotplug(struct ata_port *ap, struct ata_device *dev,
 
         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 @@ static const struct acpi_dock_ops ata_acpi_ap_dock_ops = {
         .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 @@ void ata_acpi_dissociate(struct ata_host *host)
                 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 @@ static int __ata_acpi_gtm(struct ata_port *ap, acpi_handle handle,
         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 @@ int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm)
         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 @@ void ata_acpi_on_resume(struct ata_port *ap)
         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 @@ static int ata_acpi_choose_suspend_state(struct ata_device *dev, bool runtime)
                 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 @@ static void pata_acpi_set_state(struct ata_port *ap, pm_message_t state)
         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 @@ void ata_acpi_on_disable(struct ata_device *dev)
         ata_acpi_clear_gtf(dev);
 }
 
-static int compat_pci_ata(struct ata_port *ap)
-{
-        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;
-}
-
-static int ata_acpi_bind_host(struct ata_port *ap, acpi_handle *handle)
-{
-        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)
+void ata_scsi_acpi_bind(struct ata_device *dev)
 {
-        return scsi_register_acpi_bus_type(&ata_acpi_bus);
+        acpi_handle handle = ata_dev_acpi_handle(dev);
+        if (handle)
+                acpi_dev_pm_add_dependent(handle, &dev->sdev->sdev_gendev);
 }
 
-void ata_acpi_unregister(void)
+void ata_scsi_acpi_unbind(struct ata_device *dev)
 {
-        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);
 }