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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Greybus operations
4 *
5 * Copyright 2014 Google Inc.
6 * Copyright 2014 Linaro Ltd.
7 */
8
9#ifndef __OPERATION_H
10#define __OPERATION_H
11
12#include <linux/completion.h>
13#include <linux/kref.h>
14#include <linux/timer.h>
15#include <linux/types.h>
16#include <linux/workqueue.h>
17
18struct gb_host_device;
19struct gb_operation;
20
21/* The default amount of time a request is given to complete */
22#define GB_OPERATION_TIMEOUT_DEFAULT 1000 /* milliseconds */
23
24/*
25 * The top bit of the type in an operation message header indicates
26 * whether the message is a request (bit clear) or response (bit set)
27 */
28#define GB_MESSAGE_TYPE_RESPONSE ((u8)0x80)
29
30enum gb_operation_result {
31 GB_OP_SUCCESS = 0x00,
32 GB_OP_INTERRUPTED = 0x01,
33 GB_OP_TIMEOUT = 0x02,
34 GB_OP_NO_MEMORY = 0x03,
35 GB_OP_PROTOCOL_BAD = 0x04,
36 GB_OP_OVERFLOW = 0x05,
37 GB_OP_INVALID = 0x06,
38 GB_OP_RETRY = 0x07,
39 GB_OP_NONEXISTENT = 0x08,
40 GB_OP_UNKNOWN_ERROR = 0xfe,
41 GB_OP_MALFUNCTION = 0xff,
42};
43
44#define GB_OPERATION_MESSAGE_SIZE_MIN sizeof(struct gb_operation_msg_hdr)
45#define GB_OPERATION_MESSAGE_SIZE_MAX U16_MAX
46
47/*
48 * Protocol code should only examine the payload and payload_size fields, and
49 * host-controller drivers may use the hcpriv field. All other fields are
50 * intended to be private to the operations core code.
51 */
52struct gb_message {
53 struct gb_operation *operation;
54 struct gb_operation_msg_hdr *header;
55
56 void *payload;
57 size_t payload_size;
58
59 void *buffer;
60
61 void *hcpriv;
62};
63
64#define GB_OPERATION_FLAG_INCOMING BIT(0)
65#define GB_OPERATION_FLAG_UNIDIRECTIONAL BIT(1)
66#define GB_OPERATION_FLAG_SHORT_RESPONSE BIT(2)
67#define GB_OPERATION_FLAG_CORE BIT(3)
68
69#define GB_OPERATION_FLAG_USER_MASK (GB_OPERATION_FLAG_SHORT_RESPONSE | \
70 GB_OPERATION_FLAG_UNIDIRECTIONAL)
71
72/*
73 * A Greybus operation is a remote procedure call performed over a
74 * connection between two UniPro interfaces.
75 *
76 * Every operation consists of a request message sent to the other
77 * end of the connection coupled with a reply message returned to
78 * the sender. Every operation has a type, whose interpretation is
79 * dependent on the protocol associated with the connection.
80 *
81 * Only four things in an operation structure are intended to be
82 * directly usable by protocol handlers: the operation's connection
83 * pointer; the operation type; the request message payload (and
84 * size); and the response message payload (and size). Note that a
85 * message with a 0-byte payload has a null message payload pointer.
86 *
87 * In addition, every operation has a result, which is an errno
88 * value. Protocol handlers access the operation result using
89 * gb_operation_result().
90 */
91typedef void (*gb_operation_callback)(struct gb_operation *);
92struct gb_operation {
93 struct gb_connection *connection;
94 struct gb_message *request;
95 struct gb_message *response;
96
97 unsigned long flags;
98 u8 type;
99 u16 id;
100 int errno; /* Operation result */
101
102 struct work_struct work;
103 gb_operation_callback callback;
104 struct completion completion;
105 struct timer_list timer;
106
107 struct kref kref;
108 atomic_t waiters;
109
110 int active;
111 struct list_head links; /* connection->operations */
112
113 void *private;
114};
115
116static inline bool
117gb_operation_is_incoming(struct gb_operation *operation)
118{
119 return operation->flags & GB_OPERATION_FLAG_INCOMING;
120}
121
122static inline bool
123gb_operation_is_unidirectional(struct gb_operation *operation)
124{
125 return operation->flags & GB_OPERATION_FLAG_UNIDIRECTIONAL;
126}
127
128static inline bool
129gb_operation_short_response_allowed(struct gb_operation *operation)
130{
131 return operation->flags & GB_OPERATION_FLAG_SHORT_RESPONSE;
132}
133
134static inline bool gb_operation_is_core(struct gb_operation *operation)
135{
136 return operation->flags & GB_OPERATION_FLAG_CORE;
137}
138
139void gb_connection_recv(struct gb_connection *connection,
140 void *data, size_t size);
141
142int gb_operation_result(struct gb_operation *operation);
143
144size_t gb_operation_get_payload_size_max(struct gb_connection *connection);
145struct gb_operation *
146gb_operation_create_flags(struct gb_connection *connection,
147 u8 type, size_t request_size,
148 size_t response_size, unsigned long flags,
149 gfp_t gfp);
150
151static inline struct gb_operation *
152gb_operation_create(struct gb_connection *connection,
153 u8 type, size_t request_size,
154 size_t response_size, gfp_t gfp)
155{
156 return gb_operation_create_flags(connection, type, request_size,
157 response_size, 0, gfp);
158}
159
160struct gb_operation *
161gb_operation_create_core(struct gb_connection *connection,
162 u8 type, size_t request_size,
163 size_t response_size, unsigned long flags,
164 gfp_t gfp);
165
166void gb_operation_get(struct gb_operation *operation);
167void gb_operation_put(struct gb_operation *operation);
168
169bool gb_operation_response_alloc(struct gb_operation *operation,
170 size_t response_size, gfp_t gfp);
171
172int gb_operation_request_send(struct gb_operation *operation,
173 gb_operation_callback callback,
174 unsigned int timeout,
175 gfp_t gfp);
176int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
177 unsigned int timeout);
178static inline int
179gb_operation_request_send_sync(struct gb_operation *operation)
180{
181 return gb_operation_request_send_sync_timeout(operation,
182 GB_OPERATION_TIMEOUT_DEFAULT);
183}
184
185void gb_operation_cancel(struct gb_operation *operation, int errno);
186void gb_operation_cancel_incoming(struct gb_operation *operation, int errno);
187
188void greybus_message_sent(struct gb_host_device *hd,
189 struct gb_message *message, int status);
190
191int gb_operation_sync_timeout(struct gb_connection *connection, int type,
192 void *request, int request_size,
193 void *response, int response_size,
194 unsigned int timeout);
195int gb_operation_unidirectional_timeout(struct gb_connection *connection,
196 int type, void *request, int request_size,
197 unsigned int timeout);
198
199static inline int gb_operation_sync(struct gb_connection *connection, int type,
200 void *request, int request_size,
201 void *response, int response_size)
202{
203 return gb_operation_sync_timeout(connection, type,
204 request, request_size, response, response_size,
205 GB_OPERATION_TIMEOUT_DEFAULT);
206}
207
208static inline int gb_operation_unidirectional(struct gb_connection *connection,
209 int type, void *request, int request_size)
210{
211 return gb_operation_unidirectional_timeout(connection, type,
212 request, request_size, GB_OPERATION_TIMEOUT_DEFAULT);
213}
214
215static inline void *gb_operation_get_data(struct gb_operation *operation)
216{
217 return operation->private;
218}
219
220static inline void gb_operation_set_data(struct gb_operation *operation,
221 void *data)
222{
223 operation->private = data;
224}
225
226int gb_operation_init(void);
227void gb_operation_exit(void);
228
229#endif /* !__OPERATION_H */