5 files changed, 281 insertions, 86 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ebcf534514be..fc06945d3f99 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -326,6 +326,23 @@ config ACPI_THERMAL
 	  To compile this driver as a module, choose M here:
 	  the module will be called thermal.
 
+config ACPI_PLATFORM_PROFILE
+	tristate "ACPI Platform Profile Driver"
+	default m
+	help
+	  This driver adds support for platform-profiles on platforms that
+	  support it.
+
+	  Platform-profiles can be used to control the platform behaviour. For
+	  example whether to operate in a lower power mode, in a higher
+	  power performance mode or between the two.
+
+	  This driver provides the sysfs interface and is used as the registration
+	  point for platform specific drivers.
+
+	  Which profiles are supported is determined on a per-platform basis and
+	  should be obtained from the platform specific driver.
+
 config ACPI_CUSTOM_DSDT_FILE
 	string "Custom DSDT Table file to include"
 	default ""
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 076894a3330f..52b627c7f977 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -79,6 +79,7 @@ obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
 obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
 obj-$(CONFIG_ACPI)		+= container.o
 obj-$(CONFIG_ACPI_THERMAL)	+= thermal.o
+obj-$(CONFIG_ACPI_PLATFORM_PROFILE) 	+= platform_profile.o
 obj-$(CONFIG_ACPI_NFIT)		+= nfit/
 obj-$(CONFIG_ACPI_NUMA)		+= numa/
 obj-$(CONFIG_ACPI)		+= acpi_memhotplug.o
diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
new file mode 100644
index 000000000000..4a59c5993bde
--- /dev/null
+++ b/drivers/acpi/platform_profile.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/* Platform profile sysfs interface */
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/platform_profile.h>
+#include <linux/sysfs.h>
+
+static struct platform_profile_handler *cur_profile;
+static DEFINE_MUTEX(profile_lock);
+
+static const char * const profile_names[] = {
+	[PLATFORM_PROFILE_LOW_POWER] = "low-power",
+	[PLATFORM_PROFILE_COOL] = "cool",
+	[PLATFORM_PROFILE_QUIET] = "quiet",
+	[PLATFORM_PROFILE_BALANCED] = "balanced",
+	[PLATFORM_PROFILE_PERFORMANCE] = "performance",
+};
+static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
+
+static ssize_t platform_profile_choices_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int len = 0;
+	int err, i;
+
+	err = mutex_lock_interruptible(&profile_lock);
+	if (err)
+		return err;
+
+	if (!cur_profile) {
+		mutex_unlock(&profile_lock);
+		return -ENODEV;
+	}
+
+	for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
+		if (len == 0)
+			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
+		else
+			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
+	}
+	len += sysfs_emit_at(buf, len, "\n");
+	mutex_unlock(&profile_lock);
+	return len;
+}
+
+static ssize_t platform_profile_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
+	int err;
+
+	err = mutex_lock_interruptible(&profile_lock);
+	if (err)
+		return err;
+
+	if (!cur_profile) {
+		mutex_unlock(&profile_lock);
+		return -ENODEV;
+	}
+
+	err = cur_profile->profile_get(cur_profile, &profile);
+	mutex_unlock(&profile_lock);
+	if (err)
+		return err;
+
+	/* Check that profile is valid index */
+	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
+		return -EIO;
+
+	return sysfs_emit(buf, "%s\n", profile_names[profile]);
+}
+
+static ssize_t platform_profile_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	int err, i;
+
+	err = mutex_lock_interruptible(&profile_lock);
+	if (err)
+		return err;
+
+	if (!cur_profile) {
+		mutex_unlock(&profile_lock);
+		return -ENODEV;
+	}
+
+	/* Scan for a matching profile */
+	i = sysfs_match_string(profile_names, buf);
+	if (i < 0) {
+		mutex_unlock(&profile_lock);
+		return -EINVAL;
+	}
+
+	/* Check that platform supports this profile choice */
+	if (!test_bit(i, cur_profile->choices)) {
+		mutex_unlock(&profile_lock);
+		return -EOPNOTSUPP;
+	}
+
+	err = cur_profile->profile_set(cur_profile, i);
+	mutex_unlock(&profile_lock);
+	if (err)
+		return err;
+	return count;
+}
+
+static DEVICE_ATTR_RO(platform_profile_choices);
+static DEVICE_ATTR_RW(platform_profile);
+
+static struct attribute *platform_profile_attrs[] = {
+	&dev_attr_platform_profile_choices.attr,
+	&dev_attr_platform_profile.attr,
+	NULL
+};
+
+static const struct attribute_group platform_profile_group = {
+	.attrs = platform_profile_attrs
+};
+
+void platform_profile_notify(void)
+{
+	if (!cur_profile)
+		return;
+	sysfs_notify(acpi_kobj, NULL, "platform_profile");
+}
+EXPORT_SYMBOL_GPL(platform_profile_notify);
+
+int platform_profile_register(struct platform_profile_handler *pprof)
+{
+	int err;
+
+	mutex_lock(&profile_lock);
+	/* We can only have one active profile */
+	if (cur_profile) {
+		mutex_unlock(&profile_lock);
+		return -EEXIST;
+	}
+
+	/* Sanity check the profile handler field are set */
+	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
+		!pprof->profile_set || !pprof->profile_get) {
+		mutex_unlock(&profile_lock);
+		return -EINVAL;
+	}
+
+	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
+	if (err) {
+		mutex_unlock(&profile_lock);
+		return err;
+	}
+
+	cur_profile = pprof;
+	mutex_unlock(&profile_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(platform_profile_register);
+
+int platform_profile_remove(void)
+{
+	sysfs_remove_group(acpi_kobj, &platform_profile_group);
+
+	mutex_lock(&profile_lock);
+	cur_profile = NULL;
+	mutex_unlock(&profile_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(platform_profile_remove);
+
+MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 24e87b630573..e312ebaed8db 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -564,7 +564,7 @@ int acpi_node_prop_get(const struct fwnode_handle *fwnode,
 
 /**
  * acpi_data_get_property_array - return an ACPI array property with given name
- * @adev: ACPI data object to get the property from
+ * @data: ACPI data object to get the property from
  * @name: Name of the property
  * @type: Expected type of array elements
  * @obj: Location to store a pointer to the property value (if not NULL)
@@ -787,9 +787,6 @@ static int acpi_data_prop_read_single(const struct acpi_device_data *data,
 	const union acpi_object *obj;
 	int ret;
 
-	if (!val)
-		return -EINVAL;
-
 	if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);
 		if (ret)
@@ -799,28 +796,43 @@ static int acpi_data_prop_read_single(const struct acpi_device_data *data,
 		case DEV_PROP_U8:
 			if (obj->integer.value > U8_MAX)
 				return -EOVERFLOW;
-			*(u8 *)val = obj->integer.value;
+
+			if (val)
+				*(u8 *)val = obj->integer.value;
+
 			break;
 		case DEV_PROP_U16:
 			if (obj->integer.value > U16_MAX)
 				return -EOVERFLOW;
-			*(u16 *)val = obj->integer.value;
+
+			if (val)
+				*(u16 *)val = obj->integer.value;
+
 			break;
 		case DEV_PROP_U32:
 			if (obj->integer.value > U32_MAX)
 				return -EOVERFLOW;
-			*(u32 *)val = obj->integer.value;
+
+			if (val)
+				*(u32 *)val = obj->integer.value;
+
 			break;
 		default:
-			*(u64 *)val = obj->integer.value;
+			if (val)
+				*(u64 *)val = obj->integer.value;
+
 			break;
 		}
+
+		if (!val)
+			return 1;
 	} else if (proptype == DEV_PROP_STRING) {
 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);
 		if (ret)
 			return ret;
 
-		*(char **)val = obj->string.pointer;
+		if (val)
+			*(char **)val = obj->string.pointer;
 
 		return 1;
 	} else {
@@ -829,20 +841,6 @@ static int acpi_data_prop_read_single(const struct acpi_device_data *data,
 	return ret;
 }
 
-int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
-			      enum dev_prop_type proptype, void *val)
-{
-	int ret;
-
-	if (!adev)
-		return -EINVAL;
-
-	ret = acpi_data_prop_read_single(&adev->data, propname, proptype, val);
-	if (ret < 0 || proptype != ACPI_TYPE_STRING)
-		return ret;
-	return 0;
-}
-
 static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val,
 				       size_t nval)
 {
@@ -928,10 +926,20 @@ static int acpi_data_prop_read(const struct acpi_device_data *data,
 	const union acpi_object *items;
 	int ret;
 
-	if (val && nval == 1) {
+	if (nval == 1 || !val) {
 		ret = acpi_data_prop_read_single(data, propname, proptype, val);
-		if (ret >= 0)
+		/*
+		 * The overflow error means that the property is there and it is
+		 * single-value, but its type does not match, so return.
+		 */
+		if (ret >= 0 || ret == -EOVERFLOW)
 			return ret;
+
+		/*
+		 * Reading this property as a single-value one failed, but its
+		 * value may still be represented as one-element array, so
+		 * continue.
+		 */
 	}
 
 	ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);
@@ -973,12 +981,6 @@ static int acpi_data_prop_read(const struct acpi_device_data *data,
 	return ret;
 }
 
-int acpi_dev_prop_read(const struct acpi_device *adev, const char *propname,
-		       enum dev_prop_type proptype, void *val, size_t nval)
-{
-	return adev ? acpi_data_prop_read(&adev->data, propname, proptype, val, nval) : -EINVAL;
-}
-
 /**
  * acpi_node_prop_read - retrieve the value of an ACPI property with given name.
  * @fwnode: Firmware node to get the property from.
@@ -991,9 +993,9 @@ int acpi_dev_prop_read(const struct acpi_device *adev, const char *propname,
  * of the property.  Otherwise, read at most @nval values to the array at the
  * location pointed to by @val.
  */
-int acpi_node_prop_read(const struct fwnode_handle *fwnode,
-			const char *propname, enum dev_prop_type proptype,
-			void *val, size_t nval)
+static int acpi_node_prop_read(const struct fwnode_handle *fwnode,
+			       const char *propname, enum dev_prop_type proptype,
+			       void *val, size_t nval)
 {
 	return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
 				   propname, proptype, val, nval);
@@ -1210,8 +1212,7 @@ static struct fwnode_handle *acpi_graph_get_child_prop_value(
 
 /**
  * acpi_graph_get_remote_endpoint - Parses and returns remote end of an endpoint
- * @fwnode: Endpoint firmware node pointing to a remote device
- * @endpoint: Firmware node of remote endpoint is filled here if not %NULL
+ * @__fwnode: Endpoint firmware node pointing to a remote device
  *
  * Returns the remote endpoint corresponding to @__fwnode. NULL on error.
  */
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 22566b4b3150..cbdd2272d982 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -578,29 +578,31 @@ static void acpi_scan_drop_device(acpi_handle handle, void *context)
 	mutex_unlock(&acpi_device_del_lock);
 }
 
-static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
-				void (*callback)(void *))
+static struct acpi_device *handle_to_device(acpi_handle handle,
+					    void (*callback)(void *))
 {
+	struct acpi_device *adev = NULL;
 	acpi_status status;
 
-	if (!device)
-		return -EINVAL;
-
-	*device = NULL;
-
 	status = acpi_get_data_full(handle, acpi_scan_drop_device,
-				    (void **)device, callback);
-	if (ACPI_FAILURE(status) || !*device) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
-				  handle));
-		return -ENODEV;
+				    (void **)&adev, callback);
+	if (ACPI_FAILURE(status) || !adev) {
+		acpi_handle_debug(handle, "No context!\n");
+		return NULL;
 	}
-	return 0;
+	return adev;
 }
 
 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 {
-	return acpi_get_device_data(handle, device, NULL);
+	if (!device)
+		return -EINVAL;
+
+	*device = handle_to_device(handle, NULL);
+	if (!*device)
+		return -ENODEV;
+
+	return 0;
 }
 EXPORT_SYMBOL(acpi_bus_get_device);
 
@@ -612,10 +614,7 @@ static void get_acpi_device(void *dev)
 
 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
 {
-	struct acpi_device *adev = NULL;
-
-	acpi_get_device_data(handle, &adev, get_acpi_device);
-	return adev;
+	return handle_to_device(handle, get_acpi_device);
 }
 
 void acpi_bus_put_acpi_device(struct acpi_device *adev)
@@ -623,12 +622,23 @@ void acpi_bus_put_acpi_device(struct acpi_device *adev)
 	put_device(&adev->dev);
 }
 
+static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+
+	/* Find suitable bus_id and instance number in acpi_bus_id_list. */
+	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
+		if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
+			return acpi_device_bus_id;
+	}
+	return NULL;
+}
+
 int acpi_device_add(struct acpi_device *device,
 		    void (*release)(struct device *))
 {
+	struct acpi_device_bus_id *acpi_device_bus_id;
 	int result;
-	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
-	int found = 0;
 
 	if (device->handle) {
 		acpi_status status;
@@ -654,38 +664,26 @@ int acpi_device_add(struct acpi_device *device,
 	INIT_LIST_HEAD(&device->del_list);
 	mutex_init(&device->physical_node_lock);
 
-	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
-	if (!new_bus_id) {
-		pr_err(PREFIX "Memory allocation error\n");
-		result = -ENOMEM;
-		goto err_detach;
-	}
-
 	mutex_lock(&acpi_device_lock);
-	/*
-	 * Find suitable bus_id and instance number in acpi_bus_id_list
-	 * If failed, create one and link it into acpi_bus_id_list
-	 */
-	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
-		if (!strcmp(acpi_device_bus_id->bus_id,
-			    acpi_device_hid(device))) {
-			acpi_device_bus_id->instance_no++;
-			found = 1;
-			kfree(new_bus_id);
-			break;
+
+	acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
+	if (acpi_device_bus_id) {
+		acpi_device_bus_id->instance_no++;
+	} else {
+		acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
+					     GFP_KERNEL);
+		if (!acpi_device_bus_id) {
+			result = -ENOMEM;
+			goto err_unlock;
 		}
-	}
-	if (!found) {
-		acpi_device_bus_id = new_bus_id;
 		acpi_device_bus_id->bus_id =
 			kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 		if (!acpi_device_bus_id->bus_id) {
-			pr_err(PREFIX "Memory allocation error for bus id\n");
+			kfree(acpi_device_bus_id);
 			result = -ENOMEM;
-			goto err_free_new_bus_id;
+			goto err_unlock;
 		}
 
-		acpi_device_bus_id->instance_no = 0;
 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 	}
 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
@@ -695,10 +693,12 @@ int acpi_device_add(struct acpi_device *device,
 
 	if (device->wakeup.flags.valid)
 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
+
 	mutex_unlock(&acpi_device_lock);
 
 	if (device->parent)
 		device->dev.parent = &device->parent->dev;
+
 	device->dev.bus = &acpi_bus_type;
 	device->dev.release = release;
 	result = device_add(&device->dev);
@@ -714,20 +714,19 @@ int acpi_device_add(struct acpi_device *device,
 
 	return 0;
 
- err:
+err:
 	mutex_lock(&acpi_device_lock);
+
 	if (device->parent)
 		list_del(&device->node);
-	list_del(&device->wakeup_list);
 
- err_free_new_bus_id:
-	if (!found)
-		kfree(new_bus_id);
+	list_del(&device->wakeup_list);
 
+err_unlock:
 	mutex_unlock(&acpi_device_lock);
 
- err_detach:
 	acpi_detach_data(device->handle, acpi_scan_drop_device);
+
 	return result;
 }