xref: /openbmc/linux/io_uring/uring_cmd.c (revision 0e407915)
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 #include <linux/security.h>
7 
8 #include <uapi/linux/io_uring.h>
9 
10 #include "io_uring.h"
11 #include "uring_cmd.h"
12 
13 static void io_uring_cmd_work(struct io_kiocb *req, bool *locked)
14 {
15 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
16 
17 	ioucmd->task_work_cb(ioucmd);
18 }
19 
20 void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
21 			void (*task_work_cb)(struct io_uring_cmd *))
22 {
23 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
24 
25 	ioucmd->task_work_cb = task_work_cb;
26 	req->io_task_work.func = io_uring_cmd_work;
27 	io_req_task_work_add(req);
28 }
29 EXPORT_SYMBOL_GPL(io_uring_cmd_complete_in_task);
30 
31 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
32 					  u64 extra1, u64 extra2)
33 {
34 	req->extra1 = extra1;
35 	req->extra2 = extra2;
36 	req->flags |= REQ_F_CQE32_INIT;
37 }
38 
39 /*
40  * Called by consumers of io_uring_cmd, if they originally returned
41  * -EIOCBQUEUED upon receiving the command.
42  */
43 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2)
44 {
45 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
46 
47 	if (ret < 0)
48 		req_set_fail(req);
49 
50 	io_req_set_res(req, ret, 0);
51 	if (req->ctx->flags & IORING_SETUP_CQE32)
52 		io_req_set_cqe32_extra(req, res2, 0);
53 	__io_req_complete(req, 0);
54 }
55 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
56 
57 int io_uring_cmd_prep_async(struct io_kiocb *req)
58 {
59 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
60 	size_t cmd_size;
61 
62 	BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16);
63 	BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80);
64 
65 	cmd_size = uring_cmd_pdu_size(req->ctx->flags & IORING_SETUP_SQE128);
66 
67 	memcpy(req->async_data, ioucmd->cmd, cmd_size);
68 	return 0;
69 }
70 
71 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
72 {
73 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
74 
75 	if (sqe->rw_flags || sqe->__pad1)
76 		return -EINVAL;
77 	ioucmd->cmd = sqe->cmd;
78 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
79 	return 0;
80 }
81 
82 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
83 {
84 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
85 	struct io_ring_ctx *ctx = req->ctx;
86 	struct file *file = req->file;
87 	int ret;
88 
89 	if (!req->file->f_op->uring_cmd)
90 		return -EOPNOTSUPP;
91 
92 	ret = security_uring_cmd(ioucmd);
93 	if (ret)
94 		return ret;
95 
96 	if (ctx->flags & IORING_SETUP_SQE128)
97 		issue_flags |= IO_URING_F_SQE128;
98 	if (ctx->flags & IORING_SETUP_CQE32)
99 		issue_flags |= IO_URING_F_CQE32;
100 	if (ctx->flags & IORING_SETUP_IOPOLL)
101 		issue_flags |= IO_URING_F_IOPOLL;
102 
103 	if (req_has_async_data(req))
104 		ioucmd->cmd = req->async_data;
105 
106 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
107 	if (ret == -EAGAIN) {
108 		if (!req_has_async_data(req)) {
109 			if (io_alloc_async_data(req))
110 				return -ENOMEM;
111 			io_uring_cmd_prep_async(req);
112 		}
113 		return -EAGAIN;
114 	}
115 
116 	if (ret != -EIOCBQUEUED) {
117 		if (ret < 0)
118 			req_set_fail(req);
119 		io_req_set_res(req, ret, 0);
120 		return ret;
121 	}
122 
123 	return IOU_ISSUE_SKIP_COMPLETE;
124 }
125