1 files changed, 66 insertions, 4 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index d5cedffeeff9..2ea14648a661 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -291,6 +291,44 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr)
 }
 EXPORT_SYMBOL(acpi_get_local_address);
 
+#define ACPI_MAX_SUB_BUF_SIZE	9
+
+const char *acpi_get_subsystem_id(acpi_handle handle)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	const char *sub;
+	size_t len;
+
+	status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
+		return ERR_PTR(-ENODATA);
+	}
+
+	obj = buffer.pointer;
+	if (obj->type == ACPI_TYPE_STRING) {
+		len = strlen(obj->string.pointer);
+		if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
+			sub = kstrdup(obj->string.pointer, GFP_KERNEL);
+			if (!sub)
+				sub = ERR_PTR(-ENOMEM);
+		} else {
+			acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
+			sub = ERR_PTR(-ENODATA);
+		}
+	} else {
+		acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
+		sub = ERR_PTR(-ENODATA);
+	}
+
+	acpi_os_free(buffer.pointer);
+
+	return sub;
+}
+EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
+
 acpi_status
 acpi_evaluate_reference(acpi_handle handle,
 			acpi_string pathname,
@@ -681,7 +719,7 @@ acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
 
 	if (ret != AE_NOT_FOUND)
 		acpi_handle_warn(handle,
-				"failed to evaluate _DSM (0x%x)\n", ret);
+				 "failed to evaluate _DSM %pUb (0x%x)\n", guid, ret);
 
 	return NULL;
 }
@@ -756,6 +794,30 @@ bool acpi_dev_hid_uid_match(struct acpi_device *adev,
 EXPORT_SYMBOL(acpi_dev_hid_uid_match);
 
 /**
+ * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
+ * @adev: ACPI device to get _UID from
+ * @integer: output buffer for integer
+ *
+ * Considers _UID as integer and converts it to @integer.
+ *
+ * Returns 0 on success, or negative error code otherwise.
+ */
+int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
+{
+	const char *uid;
+
+	if (!adev)
+		return -ENODEV;
+
+	uid = acpi_device_uid(adev);
+	if (!uid)
+		return -ENODATA;
+
+	return kstrtou64(uid, 0, integer);
+}
+EXPORT_SYMBOL(acpi_dev_uid_to_integer);
+
+/**
  * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
  * @hid: Hardware ID of the device.
  *
@@ -840,7 +902,7 @@ bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 	struct acpi_dev_match_info match = {};
 	struct device *dev;
 
-	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
 	match.uid = uid;
 	match.hrv = hrv;
 
@@ -873,7 +935,7 @@ acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const cha
 	struct acpi_dev_match_info match = {};
 	struct device *dev;
 
-	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
 	match.uid = uid;
 	match.hrv = hrv;
 
@@ -923,7 +985,7 @@ EXPORT_SYMBOL(acpi_video_backlight_string);
 
 static int __init acpi_backlight(char *str)
 {
-	strlcpy(acpi_video_backlight_string, str,
+	strscpy(acpi_video_backlight_string, str,
 		sizeof(acpi_video_backlight_string));
 	return 1;
 }