xref: /openbmc/linux/io_uring/uring_cmd.c (revision e79e40c8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/io_uring.h>
6 
7 #include <uapi/linux/io_uring.h>
8 
9 #include "io_uring.h"
10 #include "uring_cmd.h"
11 
12 static void io_uring_cmd_work(struct io_kiocb *req, bool *locked)
13 {
14 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
15 
16 	ioucmd->task_work_cb(ioucmd);
17 }
18 
19 void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
20 			void (*task_work_cb)(struct io_uring_cmd *))
21 {
22 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
23 
24 	ioucmd->task_work_cb = task_work_cb;
25 	req->io_task_work.func = io_uring_cmd_work;
26 	io_req_task_work_add(req);
27 }
28 EXPORT_SYMBOL_GPL(io_uring_cmd_complete_in_task);
29 
30 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
31 					  u64 extra1, u64 extra2)
32 {
33 	req->extra1 = extra1;
34 	req->extra2 = extra2;
35 	req->flags |= REQ_F_CQE32_INIT;
36 }
37 
38 /*
39  * Called by consumers of io_uring_cmd, if they originally returned
40  * -EIOCBQUEUED upon receiving the command.
41  */
42 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2)
43 {
44 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
45 
46 	if (ret < 0)
47 		req_set_fail(req);
48 
49 	io_req_set_res(req, ret, 0);
50 	if (req->ctx->flags & IORING_SETUP_CQE32)
51 		io_req_set_cqe32_extra(req, res2, 0);
52 	__io_req_complete(req, 0);
53 }
54 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
55 
56 int io_uring_cmd_prep_async(struct io_kiocb *req)
57 {
58 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
59 	size_t cmd_size;
60 
61 	BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16);
62 	BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80);
63 
64 	cmd_size = uring_cmd_pdu_size(req->ctx->flags & IORING_SETUP_SQE128);
65 
66 	memcpy(req->async_data, ioucmd->cmd, cmd_size);
67 	return 0;
68 }
69 
70 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
71 {
72 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
73 
74 	if (sqe->rw_flags || sqe->__pad1)
75 		return -EINVAL;
76 	ioucmd->cmd = sqe->cmd;
77 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
78 	return 0;
79 }
80 
81 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
82 {
83 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
84 	struct io_ring_ctx *ctx = req->ctx;
85 	struct file *file = req->file;
86 	int ret;
87 
88 	if (!req->file->f_op->uring_cmd)
89 		return -EOPNOTSUPP;
90 
91 	if (ctx->flags & IORING_SETUP_SQE128)
92 		issue_flags |= IO_URING_F_SQE128;
93 	if (ctx->flags & IORING_SETUP_CQE32)
94 		issue_flags |= IO_URING_F_CQE32;
95 	if (ctx->flags & IORING_SETUP_IOPOLL)
96 		issue_flags |= IO_URING_F_IOPOLL;
97 
98 	if (req_has_async_data(req))
99 		ioucmd->cmd = req->async_data;
100 
101 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
102 	if (ret == -EAGAIN) {
103 		if (!req_has_async_data(req)) {
104 			if (io_alloc_async_data(req))
105 				return -ENOMEM;
106 			io_uring_cmd_prep_async(req);
107 		}
108 		return -EAGAIN;
109 	}
110 
111 	if (ret != -EIOCBQUEUED) {
112 		if (ret < 0)
113 			req_set_fail(req);
114 		io_req_set_res(req, ret, 0);
115 		return IOU_OK;
116 	}
117 
118 	return IOU_ISSUE_SKIP_COMPLETE;
119 }
120