On 9/10/24 8:01 AM, Kanchan Joshi wrote:
diff --git a/include/linux/rw_hint.h b/include/linux/rw_hint.h
index b9942f5f13d3..ff708a75e2f6 100644
--- a/include/linux/rw_hint.h
+++ b/include/linux/rw_hint.h
@@ -21,4 +21,17 @@ enum rw_lifetime_hint {
static_assert(sizeof(enum rw_lifetime_hint) == 1);
#endif
+#define WRITE_HINT_TYPE_BIT BIT(7)
+#define WRITE_HINT_VAL_MASK (WRITE_HINT_TYPE_BIT - 1)
+#define WRITE_HINT_TYPE(h) (((h) & WRITE_HINT_TYPE_BIT) ? \
+ TYPE_RW_PLACEMENT_HINT : TYPE_RW_LIFETIME_HINT)
+#define WRITE_HINT_VAL(h) ((h) & WRITE_HINT_VAL_MASK)
+
+#define WRITE_PLACEMENT_HINT(h) (((h) & WRITE_HINT_TYPE_BIT) ? \
+ WRITE_HINT_VAL(h) : 0)
+#define WRITE_LIFETIME_HINT(h) (((h) & WRITE_HINT_TYPE_BIT) ? \
+ 0 : WRITE_HINT_VAL(h))
+
+#define PLACEMENT_HINT_TYPE WRITE_HINT_TYPE_BIT
+#define MAX_PLACEMENT_HINT_VAL (WRITE_HINT_VAL_MASK - 1)
#endif /* _LINUX_RW_HINT_H */
The above macros implement a union of two 7-bit types in an 8-bit field.
Wouldn't we be better of by using two separate 8-bit values such that we
don't need the above macros?
Thanks,
Bart.
