io_uring/register: move io_uring_register(2) related code to register.c

Most of this code is basically self contained, move it out of the core
io_uring file to bring a bit more separation to the registration related
bits. This moves another ~10% of the code into register.c.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/Makefile

@@ -8,6 +8,6 @@ obj-$(CONFIG_IO_URING)		+= io_uring.o xattr.o nop.o fs.o splice.o \
 					statx.o net.o msg_ring.o timeout.o \
 					sqpoll.o fdinfo.o tctx.o poll.o \
 					cancel.o kbuf.o rsrc.o rw.o opdef.o \
-					notif.o waitid.o
+					notif.o waitid.o register.o
 obj-$(CONFIG_IO_WQ)		+= io-wq.o
 obj-$(CONFIG_FUTEX)		+= futex.o

io_uring/io_uring.h

@@ -79,6 +79,14 @@ bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
 void *io_mem_alloc(size_t size);
 void io_mem_free(void *ptr);
 
+enum {
+	IO_EVENTFD_OP_SIGNAL_BIT,
+	IO_EVENTFD_OP_FREE_BIT,
+};
+
+void io_eventfd_ops(struct rcu_head *rcu);
+void io_activate_pollwq(struct io_ring_ctx *ctx);
+
 #if defined(CONFIG_PROVE_LOCKING)
 static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx)
 {

io_uring/register.h

+// SPDX-License-Identifier: GPL-2.0
+#ifndef IORING_REGISTER_H
+#define IORING_REGISTER_H
+
+int io_eventfd_unregister(struct io_ring_ctx *ctx);
+int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id);
+
+#endif