[PATCH v6 15/22] ACPI: platform_profile: Only show profiles common for all handlers

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

If multiple platform profile handlers have been registered, don't allow
switching to profiles unique to only one handler.

Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * adjust mutex use
---
 drivers/acpi/platform_profile.c | 56 ++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index c4d451782ff18..c4e2c75116988 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -206,26 +206,54 @@ static const struct class platform_profile_class = {
 	.dev_groups = profile_groups,
 };
 
+/**
+ * _aggregate_choices - Aggregate the available profile choices
+ * @dev: The device
+ * @data: The available profile choices
+ * Return: 0 on success, -errno on failure
+ */
+static int _aggregate_choices(struct device *dev, void *data)
+{
+	struct platform_profile_handler *handler;
+	unsigned long *aggregate = data;
+
+	lockdep_assert_held(&profile_lock);
+	handler = dev_get_drvdata(dev);
+	if (test_bit(PLATFORM_PROFILE_LAST, aggregate))
+		bitmap_copy(aggregate, handler->choices, PLATFORM_PROFILE_LAST);
+	else
+		bitmap_and(aggregate, handler->choices, aggregate, PLATFORM_PROFILE_LAST);
+
+	return 0;
+}
+
+/**
+ * platform_profile_choices_show - Show the available profile choices 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_choices_show(struct device *dev,
-					struct device_attribute *attr,
-					char *buf)
+					     struct device_attribute *attr,
+					     char *buf)
 {
-	int len = 0;
-	int i;
+	unsigned long aggregate[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
+	int err;
 
+	set_bit(PLATFORM_PROFILE_LAST, aggregate);
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
-		if (!cur_profile)
-			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]);
-		}
+		err = class_for_each_device(&platform_profile_class, NULL,
+					    aggregate, _aggregate_choices);
+		if (err)
+			return err;
 	}
-	len += sysfs_emit_at(buf, len, "\n");
 
-	return len;
+	/* no profile handler registered any more */
+	if (bitmap_empty(aggregate, PLATFORM_PROFILE_LAST))
+		return -EINVAL;
+
+	return _commmon_choices_show(aggregate, buf);
 }
 
 static ssize_t platform_profile_show(struct device *dev,
-- 
2.43.0