[PATCH v2 1/8] io_uring.h: add IORING_SETUP_SQE128 and IORING_SETUP_CQE32

[Ankit Kumar <ankit.kumar@samsung.com>]

From: Anuj Gupta <anuj20.g@samsung.com>

This asks the kernel to setup a ring with 128-byte SQE and
32-byte CQE entries. It may fail with -EINVAL if the kernel
doesn't support this feature. If the kernel does support this
feature, then the ring will support big-sqe/big-cqe entries
which some commands may require.

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
---
 os/linux/io_uring.h | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/os/linux/io_uring.h b/os/linux/io_uring.h
index 42b2fe84..2fa66135 100644
--- a/os/linux/io_uring.h
+++ b/os/linux/io_uring.h
@@ -60,7 +60,17 @@ struct io_uring_sqe {
 		__s32	splice_fd_in;
 		__u32	file_index;
 	};
-	__u64	__pad2[2];
+	union {
+		struct {
+			__u64	addr3;
+			__u64	__pad2[1];
+		};
+		/*
+		 * If the ring is initialized with IORING_SETUP_SQE128, then
+		 * this field is used for 80 bytes of arbitrary command data
+		 */
+		__u8	cmd[0];
+	};
 };
 
 enum {
@@ -101,6 +111,24 @@ enum {
 #define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */
 #define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */
 #define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */
+#define IORING_SETUP_SUBMIT_ALL	(1U << 7)	/* continue submit on error */
+/*
+ * Cooperative task running. When requests complete, they often require
+ * forcing the submitter to transition to the kernel to complete. If this
+ * flag is set, work will be done when the task transitions anyway, rather
+ * than force an inter-processor interrupt reschedule. This avoids interrupting
+ * a task running in userspace, and saves an IPI.
+ */
+#define IORING_SETUP_COOP_TASKRUN	(1U << 8)
+/*
+ * If COOP_TASKRUN is set, get notified if task work is available for
+ * running and a kernel transition would be needed to run it. This sets
+ * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
+ */
+#define IORING_SETUP_TASKRUN_FLAG	(1U << 9)
+
+#define IORING_SETUP_SQE128		(1U << 10) /* SQEs are 128 byte */
+#define IORING_SETUP_CQE32		(1U << 11) /* CQEs are 32 byte */
 
 enum {
 	IORING_OP_NOP,
@@ -192,6 +220,12 @@ struct io_uring_cqe {
 	__u64	user_data;	/* sqe->data submission passed back */
 	__s32	res;		/* result code for this event */
 	__u32	flags;
+
+	/*
+	 * If the ring is initialized with IORING_SETUP_CQE32, then this field
+	 * contains 16-bytes of padding, doubling the size of the CQE.
+	 */
+	__u64 big_cqe[];
 };
 
 /*
-- 
2.17.1