[PATCH liburing v2 2/5] liburing: add zc send and notif helpers

[Pavel Begunkov <asml.silence@gmail.com>]

Add helpers for notification registration and preparing zerocopy send
requests.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 src/include/liburing.h | 42 ++++++++++++++++++++++++++++++++++++++++++
 src/liburing.map       |  2 ++
 src/register.c         | 20 ++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index fc7613d..20cd308 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -189,6 +189,10 @@ int io_uring_register_sync_cancel(struct io_uring *ring,
 int io_uring_register_file_alloc_range(struct io_uring *ring,
 					unsigned off, unsigned len);
 
+int io_uring_register_notifications(struct io_uring *ring, unsigned nr,
+				    struct io_uring_notification_slot *slots);
+int io_uring_unregister_notifications(struct io_uring *ring);
+
 /*
  * Helper for the peek/wait single cqe functions. Exported because of that,
  * but probably shouldn't be used directly in an application.
@@ -677,6 +681,44 @@ static inline void io_uring_prep_send(struct io_uring_sqe *sqe, int sockfd,
 	sqe->msg_flags = (__u32) flags;
 }
 
+static inline void io_uring_prep_sendzc(struct io_uring_sqe *sqe, int sockfd,
+				        const void *buf, size_t len, int flags,
+				        unsigned slot_idx, unsigned zc_flags)
+{
+	io_uring_prep_rw(IORING_OP_SENDZC_NOTIF, sqe, sockfd, buf, (__u32) len, 0);
+	sqe->msg_flags = (__u32) flags;
+	sqe->notification_idx = slot_idx;
+	sqe->ioprio = zc_flags;
+}
+
+static inline void io_uring_prep_sendzc_fixed(struct io_uring_sqe *sqe, int sockfd,
+					      const void *buf, size_t len,
+					      int flags, unsigned slot_idx,
+					      unsigned zc_flags, unsigned buf_idx)
+{
+	io_uring_prep_sendzc(sqe, sockfd, buf, len, flags, slot_idx, zc_flags);
+	sqe->ioprio |= IORING_RECVSEND_FIXED_BUF;
+	sqe->buf_index = buf_idx;
+}
+
+static inline void io_uring_prep_sendzc_set_addr(struct io_uring_sqe *sqe,
+						 const struct sockaddr *dest_addr,
+						 __u16 addr_len)
+{
+	sqe->addr2 = (unsigned long)(void *)dest_addr;
+	sqe->addr_len = addr_len;
+}
+
+static inline void io_uring_prep_notif_update(struct io_uring_sqe *sqe,
+					      __u64 new_tag, /* 0 to ignore */
+					      unsigned offset, unsigned nr)
+{
+	io_uring_prep_rw(IORING_OP_FILES_UPDATE, sqe, -1, 0, nr,
+			 (__u64)offset);
+	sqe->addr = new_tag;
+	sqe->ioprio = IORING_RSRC_UPDATE_NOTIF;
+}
+
 static inline void io_uring_prep_recv(struct io_uring_sqe *sqe, int sockfd,
 				      void *buf, size_t len, int flags)
 {
diff --git a/src/liburing.map b/src/liburing.map
index 318d3d7..7d8f143 100644
--- a/src/liburing.map
+++ b/src/liburing.map
@@ -60,4 +60,6 @@ LIBURING_2.3 {
 	global:
 		io_uring_register_sync_cancel;
 		io_uring_register_file_alloc_range;
+		io_uring_register_notifications;
+		io_uring_unregister_notifications;
 } LIBURING_2.2;
diff --git a/src/register.c b/src/register.c
index 2b37e5f..7482112 100644
--- a/src/register.c
+++ b/src/register.c
@@ -364,3 +364,23 @@ int io_uring_register_file_alloc_range(struct io_uring *ring,
 				       IORING_REGISTER_FILE_ALLOC_RANGE, &range,
 				       0);
 }
+
+int io_uring_register_notifications(struct io_uring *ring, unsigned nr,
+				    struct io_uring_notification_slot *slots)
+{
+	struct io_uring_notification_register r = {
+		.nr_slots = nr,
+		.data = (unsigned long)slots,
+	};
+
+	return __sys_io_uring_register(ring->ring_fd,
+				       IORING_REGISTER_NOTIFIERS,
+				       &r, sizeof(r));
+}
+
+int io_uring_unregister_notifications(struct io_uring *ring)
+{
+	return __sys_io_uring_register(ring->ring_fd,
+				       IORING_UNREGISTER_NOTIFIERS,
+				       NULL, 0);
+}
-- 
2.37.0