[PATCH v3 5/5] nvme: add vectored-io support for uring-cmd

[Pankaj Raghav <p.raghav@samsung.com>]

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

wire up support for async passthru that takes an array of buffers (using
iovec). Exposed via a new op NVME_URING_CMD_IO_VEC. Same 'struct
nvme_uring_cmd' is to be used with -

1. cmd.addr as base address of user iovec array
2. cmd.vec_cnt as count of iovec array elements

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
---
 drivers/nvme/host/ioctl.c       | 9 ++++++---
 include/uapi/linux/nvme_ioctl.h | 6 +++++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index e428d692375a..ffc695aa5ba3 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -409,7 +409,7 @@ static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 }
 
 static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
-		struct io_uring_cmd *ioucmd)
+		struct io_uring_cmd *ioucmd, bool vec)
 {
 	struct nvme_uring_cmd *cmd =
 		(struct nvme_uring_cmd *)ioucmd->cmd;
@@ -446,7 +446,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	req = nvme_alloc_user_request(q, &c, nvme_to_user_ptr(cmd->addr),
 			cmd->data_len, nvme_to_user_ptr(cmd->metadata),
 			cmd->metadata_len, 0, cmd->timeout_ms ?
-			msecs_to_jiffies(cmd->timeout_ms) : 0, 0, rq_flags,
+			msecs_to_jiffies(cmd->timeout_ms) : 0, vec, rq_flags,
 			blk_flags);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -556,7 +556,10 @@ static void nvme_ns_uring_cmd(struct nvme_ns *ns, struct io_uring_cmd *ioucmd)
 
 	switch (ioucmd->cmd_op) {
 	case NVME_URING_CMD_IO:
-		ret = nvme_uring_cmd_io(ns->ctrl, ns, ioucmd);
+		ret = nvme_uring_cmd_io(ns->ctrl, ns, ioucmd, false);
+		break;
+	case NVME_URING_CMD_IO_VEC:
+		ret = nvme_uring_cmd_io(ns->ctrl, ns, ioucmd, true);
 		break;
 	default:
 		ret = -ENOTTY;
diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index 04e458c649ab..938e0a0bf46f 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -81,7 +81,10 @@ struct nvme_uring_cmd {
 	__u64	metadata;
 	__u64	addr;
 	__u32	metadata_len;
-	__u32	data_len;
+	union {
+		__u32	data_len; /* for non-vectored io */
+		__u32	vec_cnt; /* for vectored io */
+	};
 	__u32	cdw10;
 	__u32	cdw11;
 	__u32	cdw12;
@@ -107,5 +110,6 @@ struct nvme_uring_cmd {
 
 /* io_uring async commands: */
 #define NVME_URING_CMD_IO	_IOWR('N', 0x80, struct nvme_uring_cmd)
+#define NVME_URING_CMD_IO_VEC	_IOWR('N', 0x81, struct nvme_uring_cmd)
 
 #endif /* _UAPI_LINUX_NVME_IOCTL_H */
-- 
2.25.1