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Diffstat (limited to 'include/uapi/linux/ioprio.h')
-rw-r--r--include/uapi/linux/ioprio.h34
1 files changed, 20 insertions, 14 deletions
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
index 77b17e08b0da..f70f2596a6bf 100644
--- a/include/uapi/linux/ioprio.h
+++ b/include/uapi/linux/ioprio.h
@@ -5,18 +5,24 @@
/*
* Gives us 8 prio classes with 13-bits of data for each class
*/
-#define IOPRIO_CLASS_SHIFT (13)
+#define IOPRIO_CLASS_SHIFT 13
+#define IOPRIO_CLASS_MASK 0x07
#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
-#define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT)
-#define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK)
-#define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data)
+#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 CFQ. RT is the realtime
- * class, it always gets premium service. 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.
+ * 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,
@@ -25,12 +31,11 @@ enum {
IOPRIO_CLASS_IDLE,
};
-#define ioprio_valid(mask) (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE)
-
/*
- * 8 best effort priority levels are supported
+ * The RT and BE priority classes both support up to 8 priority levels.
*/
-#define IOPRIO_BE_NR (8)
+#define IOPRIO_NR_LEVELS 8
+#define IOPRIO_BE_NR IOPRIO_NR_LEVELS
enum {
IOPRIO_WHO_PROCESS = 1,
@@ -39,8 +44,9 @@ enum {
};
/*
- * Fallback BE priority
+ * Fallback BE priority level.
*/
-#define IOPRIO_NORM (4)
+#define IOPRIO_NORM 4
+#define IOPRIO_BE_NORM IOPRIO_NORM
#endif /* _UAPI_LINUX_IOPRIO_H */