1 files changed, 52 insertions, 0 deletions
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
new file mode 100644
index 000000000..f70f2596a
--- /dev/null
+++ b/include/uapi/linux/ioprio.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_IOPRIO_H
+#define _UAPI_LINUX_IOPRIO_H
+
+/*
+ * Gives us 8 prio classes with 13-bits of data for each class
+ */
+#define IOPRIO_CLASS_SHIFT	13
+#define IOPRIO_CLASS_MASK	0x07
+#define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
+
+#define IOPRIO_PRIO_CLASS(ioprio)	\
+	(((ioprio) >> IOPRIO_CLASS_SHIFT) & IOPRIO_CLASS_MASK)
+#define IOPRIO_PRIO_DATA(ioprio)	((ioprio) & IOPRIO_PRIO_MASK)
+#define IOPRIO_PRIO_VALUE(class, data)	\
+	((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \
+	 ((data) & IOPRIO_PRIO_MASK))
+
+/*
+ * These are the io priority groups as implemented by the BFQ and mq-deadline
+ * schedulers. RT is the realtime class, it always gets premium service. For
+ * ATA disks supporting NCQ IO priority, RT class IOs will be processed using
+ * high priority NCQ commands. BE is the best-effort scheduling class, the
+ * default for any process. IDLE is the idle scheduling class, it is only
+ * served when no one else is using the disk.
+ */
+enum {
+	IOPRIO_CLASS_NONE,
+	IOPRIO_CLASS_RT,
+	IOPRIO_CLASS_BE,
+	IOPRIO_CLASS_IDLE,
+};
+
+/*
+ * The RT and BE priority classes both support up to 8 priority levels.
+ */
+#define IOPRIO_NR_LEVELS	8
+#define IOPRIO_BE_NR		IOPRIO_NR_LEVELS
+
+enum {
+	IOPRIO_WHO_PROCESS = 1,
+	IOPRIO_WHO_PGRP,
+	IOPRIO_WHO_USER,
+};
+
+/*
+ * Fallback BE priority level.
+ */
+#define IOPRIO_NORM	4
+#define IOPRIO_BE_NORM	IOPRIO_NORM
+
+#endif /* _UAPI_LINUX_IOPRIO_H */