IORING_TIMEOUT_IMMEDIATE_ARG allows the user to store the timeout in the
SQE without indirection to a user timespec. Update io_uring.h and extend
tests to cover the feature.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 src/include/liburing/io_uring.h |  5 ++++
 test/timeout.c                  | 44 ++++++++++++++++++++++++++++-----
 2 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index ab1450ec..74b3f86d 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -332,6 +332,10 @@ enum io_uring_op {
 
 /*
  * sqe->timeout_flags
+ *
+ * IORING_TIMEOUT_IMMEDIATE_ARG:	If set, sqe->addr stores the timeout
+ *					value in nanoseconds instead of
+ *					pointing to a timespec.
  */
 #define IORING_TIMEOUT_ABS		(1U << 0)
 #define IORING_TIMEOUT_UPDATE		(1U << 1)
@@ -340,6 +344,7 @@ enum io_uring_op {
 #define IORING_LINK_TIMEOUT_UPDATE	(1U << 4)
 #define IORING_TIMEOUT_ETIME_SUCCESS	(1U << 5)
 #define IORING_TIMEOUT_MULTISHOT	(1U << 6)
+#define IORING_TIMEOUT_IMMEDIATE_ARG	(1U << 7)
 #define IORING_TIMEOUT_CLOCK_MASK	(IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
 #define IORING_TIMEOUT_UPDATE_MASK	(IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
 /*
diff --git a/test/timeout.c b/test/timeout.c
index 003ba743..332efcbc 100644
--- a/test/timeout.c
+++ b/test/timeout.c
@@ -23,6 +23,7 @@
 static int not_supported;
 static int no_modify;
 static int no_multishot;
+static int no_immediate;
 
 static void msec_to_ts(struct __kernel_timespec *ts, unsigned int msec)
 {
@@ -30,11 +31,25 @@ static void msec_to_ts(struct __kernel_timespec *ts, unsigned int msec)
 	ts->tv_nsec = (msec % 1000) * 1000000;
 }
 
+static void t_prep_timeout_rel(struct io_uring_sqe *sqe,
+				const struct __kernel_timespec *ts,
+				bool immediate)
+{
+	if (!immediate) {
+		io_uring_prep_timeout(sqe, ts, 0, 0);
+		return;
+	}
+
+	io_uring_prep_timeout(sqe, NULL, 0, 0);
+	sqe->addr = ts->tv_sec * 1000000000 + ts->tv_nsec;
+	sqe->timeout_flags = IORING_TIMEOUT_IMMEDIATE_ARG;
+}
+
 /*
  * Test that we return to userspace if a timeout triggers, even if we
  * don't satisfy the number of events asked for.
  */
-static int test_single_timeout_many(struct io_uring *ring)
+static int test_single_timeout_many(struct io_uring *ring, bool immediate)
 {
 	struct io_uring_cqe *cqe;
 	struct io_uring_sqe *sqe;
@@ -50,7 +65,7 @@ static int test_single_timeout_many(struct io_uring *ring)
 	}
 
 	msec_to_ts(&ts, TIMEOUT_MSEC);
-	io_uring_prep_timeout(sqe, &ts, 0, 0);
+	t_prep_timeout_rel(sqe, &ts, immediate);
 
 	ret = io_uring_submit(ring);
 	if (ret <= 0) {
@@ -219,7 +234,7 @@ err:
 /*
  * Test single timeout waking us up
  */
-static int test_single_timeout(struct io_uring *ring)
+static int test_single_timeout(struct io_uring *ring, bool immediate)
 {
 	struct io_uring_cqe *cqe;
 	struct io_uring_sqe *sqe;
@@ -235,7 +250,7 @@ static int test_single_timeout(struct io_uring *ring)
 	}
 
 	msec_to_ts(&ts, TIMEOUT_MSEC);
-	io_uring_prep_timeout(sqe, &ts, 0, 0);
+	t_prep_timeout_rel(sqe, &ts, immediate);
 
 	ret = io_uring_submit(ring);
 	if (ret <= 0) {
@@ -1765,7 +1780,7 @@ int main(int argc, char *argv[])
 	ret = io_uring_queue_init(8, &sqpoll_ring, IORING_SETUP_SQPOLL);
 	sqpoll = !ret;
 
-	ret = test_single_timeout(&ring);
+	ret = test_single_timeout(&ring, false);
 	if (ret) {
 		fprintf(stderr, "test_single_timeout failed\n");
 		return ret;
@@ -1773,6 +1788,15 @@ int main(int argc, char *argv[])
 	if (not_supported)
 		return 0;
 
+	ret = test_single_timeout(&ring, true);
+	if (ret == -EINVAL) {
+		no_immediate = true;
+		printf("Immeidate timeout arguments not supported\n");
+	} else if (ret) {
+		fprintf(stderr, "test_single_timeout (imm) failed\n");
+		return ret;
+	}
+
 	ret = test_multi_timeout(&ring);
 	if (ret) {
 		fprintf(stderr, "test_multi_timeout failed\n");
@@ -1797,12 +1821,20 @@ int main(int argc, char *argv[])
 		return ret;
 	}
 
-	ret = test_single_timeout_many(&ring);
+	ret = test_single_timeout_many(&ring, false);
 	if (ret) {
 		fprintf(stderr, "test_single_timeout_many failed\n");
 		return ret;
 	}
 
+	if (!no_immediate) {
+		ret = test_single_timeout_many(&ring, true);
+		if (ret) {
+			fprintf(stderr, "test_single_timeout_many (imm) failed\n");
+			return ret;
+		}
+	}
+
 	ret = test_single_timeout_nr(&ring, 1);
 	if (ret) {
 		fprintf(stderr, "test_single_timeout_nr(1) failed\n");
-- 
2.53.0