[PATCH v5 16/20] ACPI: platform_profile: Make sure all profile handlers agree on profile

[Mario Limonciello <mario.limonciello@amd.com>]

If for any reason multiple profile handlers don't agree on the profile
return the custom profile.

Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * Notify class profile of change to legacy interface
 * Don't show warning when writing custom string, document in last patch
   instead.
 * Adjust mutex use
---
 drivers/acpi/platform_profile.c | 101 ++++++++++++++++++++++++--------
 1 file changed, 76 insertions(+), 25 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index b6f3388b4eef9..7f302ac4d3779 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -94,6 +94,22 @@ static int _store_class_profile(struct device *dev, void *data)
 	return err ? err : 0;
 }
 
+/**
+ * _notify_class_profile - Notify the class device of a profile change
+ * @dev: The class device
+ * @data: Unused
+ */
+static int _notify_class_profile(struct device *dev, void *data)
+{
+	struct platform_profile_handler *handler = dev_get_drvdata(dev);
+
+	lockdep_assert_held(&profile_lock);
+	sysfs_notify(&handler->class_dev->kobj, NULL, "platform_profile");
+	kobject_uevent(&handler->class_dev->kobj, KOBJ_CHANGE);
+
+	return 0;
+}
+
 /**
  * get_class_profile - Show the current profile for a class device
  * @dev: The class device
@@ -284,54 +300,89 @@ static ssize_t platform_profile_choices_show(struct device *dev,
 	return _commmon_choices_show(aggregate, buf);
 }
 
+/**
+ * _aggregate_profiles - Aggregate the profiles for legacy sysfs interface
+ * @dev: The device
+ * @data: The profile to return
+ * Return: 0 on success, -errno on failure
+ */
+static int _aggregate_profiles(struct device *dev, void *data)
+{
+	enum platform_profile_option *profile = data;
+	enum platform_profile_option val;
+	int err;
+
+	err = get_class_profile(dev, &val);
+	if (err)
+		return err;
+
+	if (*profile != PLATFORM_PROFILE_LAST && *profile != val)
+		*profile = PLATFORM_PROFILE_CUSTOM;
+	else
+		*profile = val;
+
+	return 0;
+}
+
+/**
+ * platform_profile_show - Show the current profile for legacy sysfs interface
+ * @dev: The device
+ * @attr: The attribute
+ * @buf: The buffer to write to
+ * Return: The number of bytes written
+ */
 static ssize_t platform_profile_show(struct device *dev,
-					struct device_attribute *attr,
-					char *buf)
+				     struct device_attribute *attr,
+				     char *buf)
 {
-	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
+	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
 	int err;
 
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
-		if (!cur_profile)
-			return -ENODEV;
-
-		err = cur_profile->profile_get(cur_profile, &profile);
+		err = class_for_each_device(&platform_profile_class, NULL,
+					    &profile, _aggregate_profiles);
 		if (err)
 			return err;
 	}
 
-	/* Check that profile is valid index */
-	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
-		return -EIO;
+	/* no profile handler registered any more */
+	if (profile == PLATFORM_PROFILE_LAST)
+		return -EINVAL;
 
 	return sysfs_emit(buf, "%s\n", profile_names[profile]);
 }
 
+/**
+ * platform_profile_store - Set the profile for legacy sysfs interface
+ * @dev: The device
+ * @attr: The attribute
+ * @buf: The buffer to read from
+ * @count: The number of bytes to read
+ * Return: The number of bytes read
+ */
 static ssize_t platform_profile_store(struct device *dev,
-			    struct device_attribute *attr,
-			    const char *buf, size_t count)
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
 {
-	int err, i;
+	int ret;
+	int i;
 
 	/* Scan for a matching profile */
 	i = sysfs_match_string(profile_names, buf);
-	if (i < 0)
+	if (i < 0 || PLATFORM_PROFILE_CUSTOM)
 		return -EINVAL;
 
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
-		if (!cur_profile)
-			return -ENODEV;
-
-		/* Check that platform supports this profile choice */
-		if (!test_bit(i, cur_profile->choices))
-			return -EOPNOTSUPP;
-
-		err = cur_profile->profile_set(cur_profile, i);
-		if (err)
-			return err;
+		ret = class_for_each_device(&platform_profile_class, NULL, &i,
+					    _store_class_profile);
+		if (ret)
+			return ret;
+		ret = class_for_each_device(&platform_profile_class, NULL, NULL,
+					    _notify_class_profile);
+		if (ret)
+			return ret;
 	}
 
-	sysfs_notify(acpi_kobj, NULL, "platform_profile");
 	return count;
 }
 
-- 
2.43.0