// SPDX-License-Identifier: GPL-2.0

/* ublk control commands, shared by kublk and ublk_cancel_ready */

#include "kublk.h"

static void ublk_ctrl_init_cmd(struct ublk_dev *dev,
		struct io_uring_sqe *sqe,
		struct ublk_ctrl_cmd_data *data)
{
	struct ublksrv_ctrl_dev_info *info = &dev->dev_info;
	struct ublksrv_ctrl_cmd *cmd = (struct ublksrv_ctrl_cmd *)ublk_get_sqe_cmd(sqe);

	sqe->fd = dev->ctrl_fd;
	sqe->opcode = IORING_OP_URING_CMD;
	sqe->ioprio = 0;

	if (data->flags & CTRL_CMD_HAS_BUF) {
		cmd->addr = data->addr;
		cmd->len = data->len;
	}

	if (data->flags & CTRL_CMD_HAS_DATA)
		cmd->data[0] = data->data[0];

	cmd->dev_id = info->dev_id;
	cmd->queue_id = -1;

	ublk_set_sqe_cmd_op(sqe, data->cmd_op);

	io_uring_sqe_set_data(sqe, cmd);
}

int __ublk_ctrl_cmd(struct ublk_dev *dev,
		struct ublk_ctrl_cmd_data *data)
{
	struct io_uring_sqe *sqe;
	struct io_uring_cqe *cqe;
	int ret = -EINVAL;

	sqe = io_uring_get_sqe(&dev->ring);
	if (!sqe) {
		ublk_err("%s: can't get sqe ret %d\n", __func__, ret);
		return ret;
	}

	ublk_ctrl_init_cmd(dev, sqe, data);

	ret = io_uring_submit(&dev->ring);
	if (ret < 0) {
		ublk_err("uring submit ret %d\n", ret);
		return ret;
	}

	ret = io_uring_wait_cqe(&dev->ring, &cqe);
	if (ret < 0) {
		ublk_err("wait cqe: %s\n", strerror(-ret));
		return ret;
	}
	io_uring_cqe_seen(&dev->ring, cqe);

	return cqe->res;
}

void ublk_ctrl_deinit(struct ublk_dev *dev)
{
	io_uring_queue_exit(&dev->ring);
	close(dev->ctrl_fd);
	free(dev);
}

struct ublk_dev *ublk_ctrl_init(void)
{
	struct ublk_dev *dev = (struct ublk_dev *)calloc(1, sizeof(*dev));
	struct ublksrv_ctrl_dev_info *info;
	int ret;

	if (!dev)
		return NULL;
	info = &dev->dev_info;
	dev->ctrl_fd = open(CTRL_DEV, O_RDWR);
	if (dev->ctrl_fd < 0) {
		free(dev);
		return NULL;
	}

	info->max_io_buf_bytes = UBLK_IO_MAX_BYTES;

	ret = ublk_setup_ring(&dev->ring, UBLK_CTRL_RING_DEPTH,
			UBLK_CTRL_RING_DEPTH, IORING_SETUP_SQE128);
	if (ret < 0) {
		ublk_err("queue_init: %s\n", strerror(-ret));
		close(dev->ctrl_fd);
		free(dev);
		return NULL;
	}
	dev->nr_fds = 1;

	return dev;
}

int ublk_ctrl_stop_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_STOP_DEV,
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_try_stop_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_TRY_STOP_DEV,
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_start_dev(struct ublk_dev *dev,
		int daemon_pid)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_START_DEV,
		.flags	= CTRL_CMD_HAS_DATA,
	};

	dev->dev_info.ublksrv_pid = data.data[0] = daemon_pid;

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_start_user_recovery(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_START_USER_RECOVERY,
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_end_user_recovery(struct ublk_dev *dev, int daemon_pid)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_END_USER_RECOVERY,
		.flags	= CTRL_CMD_HAS_DATA,
	};

	dev->dev_info.ublksrv_pid = data.data[0] = daemon_pid;

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_add_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_ADD_DEV,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64) (uintptr_t) &dev->dev_info,
		.len = sizeof(struct ublksrv_ctrl_dev_info),
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_del_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op = UBLK_U_CMD_DEL_DEV,
		.flags = 0,
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_get_info(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_GET_DEV_INFO,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64) (uintptr_t) &dev->dev_info,
		.len = sizeof(struct ublksrv_ctrl_dev_info),
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_set_params(struct ublk_dev *dev,
		struct ublk_params *params)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_SET_PARAMS,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64) (uintptr_t) params,
		.len = sizeof(*params),
	};
	params->len = sizeof(*params);
	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_get_params(struct ublk_dev *dev,
		struct ublk_params *params)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_GET_PARAMS,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64)params,
		.len = sizeof(*params),
	};

	params->len = sizeof(*params);

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_get_features(struct ublk_dev *dev,
		__u64 *features)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_GET_FEATURES,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64) (uintptr_t) features,
		.len = sizeof(*features),
	};

	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_update_size(struct ublk_dev *dev,
		__u64 nr_sects)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_UPDATE_SIZE,
		.flags	= CTRL_CMD_HAS_DATA,
	};

	data.data[0] = nr_sects;
	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_quiesce_dev(struct ublk_dev *dev, unsigned int timeout_ms)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_QUIESCE_DEV,
		.flags	= CTRL_CMD_HAS_DATA,
	};

	data.data[0] = timeout_ms;
	return __ublk_ctrl_cmd(dev, &data);
}

int ublk_ctrl_reg_buf(struct ublk_dev *dev, void *addr, size_t size,
		      __u32 flags)
{
	struct ublk_shmem_buf_reg buf_reg = {
		.addr = (unsigned long)addr,
		.len = size,
		.flags = flags,
	};
	struct ublk_ctrl_cmd_data data = {
		.cmd_op = UBLK_U_CMD_REG_BUF,
		.flags = CTRL_CMD_HAS_BUF,
		.addr = (unsigned long)&buf_reg,
		.len = sizeof(buf_reg),
	};

	return __ublk_ctrl_cmd(dev, &data);
}