The NVMe and SCSI standards define 64 different data lifetimes. Support
storing this information in the I/O priority bitfield.
The current allocation of the 16 bits in the I/O priority bitfield is as
follows:
* 15..13: I/O priority class
* 12..6: unused
* 5..3: I/O hint (CDL)
* 2..0: I/O priority level
This patch changes this into the following:
* 15..13: I/O priority class
* 12: unused
* 11..6: data lifetime
* 5..3: I/O hint (CDL)
* 2..0: I/O priority level
Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
Cc: Niklas Cassel <niklas.cassel@xxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
include/uapi/linux/ioprio.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
index bee2bdb0eedb..efe9bc450872 100644
--- a/include/uapi/linux/ioprio.h
+++ b/include/uapi/linux/ioprio.h
@@ -71,7 +71,7 @@ enum {
* class and level.
*/
#define IOPRIO_HINT_SHIFT IOPRIO_LEVEL_NR_BITS
-#define IOPRIO_HINT_NR_BITS 10
+#define IOPRIO_HINT_NR_BITS 3
#define IOPRIO_NR_HINTS (1 << IOPRIO_HINT_NR_BITS)
#define IOPRIO_HINT_MASK (IOPRIO_NR_HINTS - 1)
#define IOPRIO_PRIO_HINT(ioprio) \
@@ -102,6 +102,12 @@ enum {
IOPRIO_HINT_DEV_DURATION_LIMIT_7 = 7,
};
+#define IOPRIO_LIFETIME_SHIFT (IOPRIO_HINT_SHIFT + IOPRIO_HINT_NR_BITS)
+#define IOPRIO_LIFETIME_NR_BITS 6
+#define IOPRIO_LIFETIME_MASK ((1u << IOPRIO_LIFETIME_NR_BITS) - 1)
+#define IOPRIO_PRIO_LIFETIME(ioprio) \
+ ((ioprio >> IOPRIO_LIFETIME_SHIFT) & IOPRIO_LIFETIME_MASK)
+
#define IOPRIO_BAD_VALUE(val, max) ((val) < 0 || (val) >= (max))
/*
