ACPI / scan: More straightforward preparation of ACPI device objects

Simplify the code preparing struct acpi_device objects for
registration by removing useless code, moving different pieces of
code into the functions they belong to and making a couple of int
functions always returning 0 void.

This also fixes a possible memory leak in ACPI device registration
error code path by making acpi_device_register() detach data from
device->handle if device_register() fails and prepares the scanning
code for special-casing ACPI power resources (next patch).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 61 insertions, 117 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c6d60910e8a8..02629a810c04 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -472,6 +472,7 @@ static void acpi_free_ids(struct acpi_device *device)
                 kfree(id->id);
                 kfree(id);
         }
+        kfree(device->pnp.unique_id);
 }
 
 static void acpi_device_release(struct device *dev)
@@ -479,7 +480,6 @@ static void acpi_device_release(struct device *dev)
         struct acpi_device *acpi_dev = to_acpi_device(dev);
 
         acpi_free_ids(acpi_dev);
-        kfree(acpi_dev->pnp.unique_id);
         kfree(acpi_dev);
 }
 
@@ -623,6 +623,18 @@ static int acpi_device_register(struct acpi_device *device)
         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
         int found = 0;
 
+        if (device->handle) {
+                acpi_status status;
+
+                status = acpi_attach_data(device->handle, acpi_bus_data_handler,
+                                          device);
+                if (ACPI_FAILURE(status)) {
+                        acpi_handle_err(device->handle,
+                                        "Unable to attach device data\n");
+                        return -ENODEV;
+                }
+        }
+
         /*
          * Linkage
          * -------
@@ -637,8 +649,9 @@ static int acpi_device_register(struct acpi_device *device)
 
         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
         if (!new_bus_id) {
-                printk(KERN_ERR PREFIX "Memory allocation error\n");
-                return -ENOMEM;
+                pr_err(PREFIX "Memory allocation error\n");
+                result = -ENOMEM;
+                goto err_detach;
         }
 
         mutex_lock(&acpi_device_lock);
@@ -677,7 +690,7 @@ static int acpi_device_register(struct acpi_device *device)
         result = device_register(&device->dev);
         if (result) {
                 dev_err(&device->dev, "Error registering device\n");
-                goto end;
+                goto err;
         }
 
         result = acpi_device_setup_files(device);
@@ -687,12 +700,16 @@ static int acpi_device_register(struct acpi_device *device)
 
         device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
         return 0;
-end:
+
+ err:
         mutex_lock(&acpi_device_lock);
         if (device->parent)
                 list_del(&device->node);
         list_del(&device->wakeup_list);
         mutex_unlock(&acpi_device_lock);
+
+ err_detach:
+        acpi_detach_data(device->handle, acpi_bus_data_handler);
         return result;
 }
 
@@ -857,12 +874,6 @@ void acpi_bus_data_handler(acpi_handle handle, void *context)
         return;
 }
 
-static int acpi_bus_get_perf_flags(struct acpi_device *device)
-{
-        device->performance.state = ACPI_STATE_UNKNOWN;
-        return 0;
-}
-
 static acpi_status
 acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
                                              struct acpi_device_wakeup *wakeup)
@@ -1013,12 +1024,25 @@ static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 
 static void acpi_bus_add_power_resource(acpi_handle handle);
 
-static int acpi_bus_get_power_flags(struct acpi_device *device)
+static void acpi_bus_get_power_flags(struct acpi_device *device)
 {
         acpi_status status = 0;
         acpi_handle handle = NULL;
         u32 i = 0;
 
+        /* Power resources cannot be power manageable. */
+        if (device->device_type == ACPI_BUS_TYPE_POWER)
+                return;
+
+        /* Presence of _PS0|_PR0 indicates 'power manageable' */
+        status = acpi_get_handle(device->handle, "_PS0", &handle);
+        if (ACPI_FAILURE(status)) {
+                status = acpi_get_handle(device->handle, "_PR0", &handle);
+                if (ACPI_FAILURE(status))
+                        return;
+        }
+
+        device->flags.power_manageable = 1;
 
         /*
          * Power Management Flags
@@ -1084,16 +1108,13 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
 
         acpi_bus_init_power(device);
-
-        return 0;
 }
 
-static int acpi_bus_get_flags(struct acpi_device *device)
+static void acpi_bus_get_flags(struct acpi_device *device)
 {
         acpi_status status = AE_OK;
         acpi_handle temp = NULL;
 
-
         /* Presence of _STA indicates 'dynamic_status' */
         status = acpi_get_handle(device->handle, "_STA", &temp);
         if (ACPI_SUCCESS(status))
@@ -1113,21 +1134,6 @@ static int acpi_bus_get_flags(struct acpi_device *device)
                 if (ACPI_SUCCESS(status))
                         device->flags.ejectable = 1;
         }
-
-        /* Power resources cannot be power manageable. */
-        if (device->device_type == ACPI_BUS_TYPE_POWER)
-                return 0;
-
-        /* Presence of _PS0|_PR0 indicates 'power manageable' */
-        status = acpi_get_handle(device->handle, "_PS0", &temp);
-        if (ACPI_FAILURE(status))
-                status = acpi_get_handle(device->handle, "_PR0", &temp);
-        if (ACPI_SUCCESS(status))
-                device->flags.power_manageable = 1;
-
-        /* TBD: Performance management */
-
-        return 0;
 }
 
 static void acpi_device_get_busid(struct acpi_device *device)
@@ -1352,27 +1358,18 @@ static void acpi_device_set_id(struct acpi_device *device)
         }
 }
 
-static int acpi_device_set_context(struct acpi_device *device)
+static void acpi_init_device_object(struct acpi_device *device,
+                                     acpi_handle handle,
+                                     int type, unsigned long long sta)
 {
-        acpi_status status;
-
-        /*
-         * Context
-         * -------
-         * Attach this 'struct acpi_device' to the ACPI object.  This makes
-         * resolutions from handle->device very efficient.  Fixed hardware
-         * devices have no handles, so we skip them.
-         */
-        if (!device->handle)
-                return 0;
-
-        status = acpi_attach_data(device->handle,
-                                  acpi_bus_data_handler, device);
-        if (ACPI_SUCCESS(status))
-                return 0;
-
-        printk(KERN_ERR PREFIX "Error attaching device data\n");
-        return -ENODEV;
+        INIT_LIST_HEAD(&device->pnp.ids);
+        device->device_type = type;
+        device->handle = handle;
+        device->parent = acpi_bus_get_parent(handle);
+        STRUCT_TO_INT(device->status) = sta;
+        acpi_device_get_busid(device);
+        acpi_device_set_id(device);
+        acpi_bus_get_flags(device);
 }
 
 static int acpi_add_single_object(struct acpi_device **child,
@@ -1389,78 +1386,25 @@ static int acpi_add_single_object(struct acpi_device **child,
                 return -ENOMEM;
         }
 
-        INIT_LIST_HEAD(&device->pnp.ids);
-        device->device_type = type;
-        device->handle = handle;
-        device->parent = acpi_bus_get_parent(handle);
-        STRUCT_TO_INT(device->status) = sta;
-
-        acpi_device_get_busid(device);
-
-        /*
-         * Flags
-         * -----
-         * Note that we only look for object handles -- cannot evaluate objects
-         * until we know the device is present and properly initialized.
-         */
-        result = acpi_bus_get_flags(device);
-        if (result)
-                goto end;
-
-        /*
-         * Initialize Device
-         * -----------------
-         * TBD: Synch with Core's enumeration/initialization process.
-         */
-        acpi_device_set_id(device);
-
-        /*
-         * Power Management
-         * ----------------
-         */
-        if (device->flags.power_manageable) {
-                result = acpi_bus_get_power_flags(device);
-                if (result)
-                        goto end;
-        }
-
-        /*
-         * Wakeup device management
-         *-----------------------
-         */
+        acpi_init_device_object(device, handle, type, sta);
+        acpi_bus_get_power_flags(device);
         acpi_bus_get_wakeup_device_flags(device);
 
-        /*
-         * Performance Management
-         * ----------------------
-         */
-        if (device->flags.performance_manageable) {
-                result = acpi_bus_get_perf_flags(device);
-                if (result)
-                        goto end;
-        }
-
-        if ((result = acpi_device_set_context(device)))
-                goto end;
-
         device->flags.match_driver = match_driver;
         result = acpi_device_register(device);
-
-end:
-        if (!result) {
-                acpi_power_add_remove_device(device, true);
-                acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                        "Adding %s [%s] parent %s\n", dev_name(&device->dev),
-                         (char *) buffer.pointer,
-                         device->parent ? dev_name(&device->parent->dev) :
-                                          "(null)"));
-                kfree(buffer.pointer);
-                *child = device;
-        } else
+        if (result) {
                 acpi_device_release(&device->dev);
+                return result;
+        }
 
-        return result;
+        acpi_power_add_remove_device(device, true);
+        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
+                dev_name(&device->dev), (char *) buffer.pointer,
+                device->parent ? dev_name(&device->parent->dev) : "(null)"));
+        kfree(buffer.pointer);
+        *child = device;
+        return 0;
 }
 
 #define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \