io_uring: add CQE32 setup processing

This adds two new function to setup and fill the CQE32 result structure.
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20220426182134.136504-5-shr@fb.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -2335,12 +2335,70 @@ static inline bool __io_fill_cqe_req_filled(struct io_ring_ctx *ctx,
 					req->cqe.res, req->cqe.flags);
 }
 
+static inline bool __io_fill_cqe32_req_filled(struct io_ring_ctx *ctx,
+					      struct io_kiocb *req)
+{
+	struct io_uring_cqe *cqe;
+	u64 extra1 = req->extra1;
+	u64 extra2 = req->extra2;
+
+	trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
+				req->cqe.res, req->cqe.flags);
+
+	/*
+	 * If we can't get a cq entry, userspace overflowed the
+	 * submission (by quite a lot). Increment the overflow count in
+	 * the ring.
+	 */
+	cqe = io_get_cqe(ctx);
+	if (likely(cqe)) {
+		memcpy(cqe, &req->cqe, sizeof(struct io_uring_cqe));
+		cqe->big_cqe[0] = extra1;
+		cqe->big_cqe[1] = extra2;
+		return true;
+	}
+
+	return io_cqring_event_overflow(ctx, req->cqe.user_data,
+					req->cqe.res, req->cqe.flags);
+}
+
 static inline bool __io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags)
 {
 	trace_io_uring_complete(req->ctx, req, req->cqe.user_data, res, cflags);
 	return __io_fill_cqe(req->ctx, req->cqe.user_data, res, cflags);
 }
 
+static inline void __io_fill_cqe32_req(struct io_kiocb *req, s32 res, u32 cflags,
+				u64 extra1, u64 extra2)
+{
+	struct io_ring_ctx *ctx = req->ctx;
+	struct io_uring_cqe *cqe;
+
+	if (WARN_ON_ONCE(!(ctx->flags & IORING_SETUP_CQE32)))
+		return;
+	if (req->flags & REQ_F_CQE_SKIP)
+		return;
+
+	trace_io_uring_complete(ctx, req, req->cqe.user_data, res, cflags);
+
+	/*
+	 * If we can't get a cq entry, userspace overflowed the
+	 * submission (by quite a lot). Increment the overflow count in
+	 * the ring.
+	 */
+	cqe = io_get_cqe(ctx);
+	if (likely(cqe)) {
+		WRITE_ONCE(cqe->user_data, req->cqe.user_data);
+		WRITE_ONCE(cqe->res, res);
+		WRITE_ONCE(cqe->flags, cflags);
+		WRITE_ONCE(cqe->big_cqe[0], extra1);
+		WRITE_ONCE(cqe->big_cqe[1], extra2);
+		return;
+	}
+
+	io_cqring_event_overflow(ctx, req->cqe.user_data, res, cflags);
+}
+
 static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data,
 				     s32 res, u32 cflags)
 {