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
18 struct gb_host_device;
19 struct 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
30 enum 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 */
52 struct 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 */
91 typedef void (*gb_operation_callback)(struct gb_operation *);
92 struct 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
116 static inline bool
gb_operation_is_incoming(struct gb_operation * operation)117 gb_operation_is_incoming(struct gb_operation *operation)
118 {
119 return operation->flags & GB_OPERATION_FLAG_INCOMING;
120 }
121
122 static inline bool
gb_operation_is_unidirectional(struct gb_operation * operation)123 gb_operation_is_unidirectional(struct gb_operation *operation)
124 {
125 return operation->flags & GB_OPERATION_FLAG_UNIDIRECTIONAL;
126 }
127
128 static inline bool
gb_operation_short_response_allowed(struct gb_operation * operation)129 gb_operation_short_response_allowed(struct gb_operation *operation)
130 {
131 return operation->flags & GB_OPERATION_FLAG_SHORT_RESPONSE;
132 }
133
gb_operation_is_core(struct gb_operation * operation)134 static inline bool gb_operation_is_core(struct gb_operation *operation)
135 {
136 return operation->flags & GB_OPERATION_FLAG_CORE;
137 }
138
139 void gb_connection_recv(struct gb_connection *connection,
140 void *data, size_t size);
141
142 int gb_operation_result(struct gb_operation *operation);
143
144 size_t gb_operation_get_payload_size_max(struct gb_connection *connection);
145 struct gb_operation *
146 gb_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
151 static inline struct gb_operation *
gb_operation_create(struct gb_connection * connection,u8 type,size_t request_size,size_t response_size,gfp_t gfp)152 gb_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
160 struct gb_operation *
161 gb_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
166 void gb_operation_get(struct gb_operation *operation);
167 void gb_operation_put(struct gb_operation *operation);
168
169 bool gb_operation_response_alloc(struct gb_operation *operation,
170 size_t response_size, gfp_t gfp);
171
172 int gb_operation_request_send(struct gb_operation *operation,
173 gb_operation_callback callback,
174 unsigned int timeout,
175 gfp_t gfp);
176 int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
177 unsigned int timeout);
178 static inline int
gb_operation_request_send_sync(struct gb_operation * operation)179 gb_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
185 void gb_operation_cancel(struct gb_operation *operation, int errno);
186 void gb_operation_cancel_incoming(struct gb_operation *operation, int errno);
187
188 void greybus_message_sent(struct gb_host_device *hd,
189 struct gb_message *message, int status);
190
191 int 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);
195 int gb_operation_unidirectional_timeout(struct gb_connection *connection,
196 int type, void *request, int request_size,
197 unsigned int timeout);
198
gb_operation_sync(struct gb_connection * connection,int type,void * request,int request_size,void * response,int response_size)199 static 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
gb_operation_unidirectional(struct gb_connection * connection,int type,void * request,int request_size)208 static 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
gb_operation_get_data(struct gb_operation * operation)215 static inline void *gb_operation_get_data(struct gb_operation *operation)
216 {
217 return operation->private;
218 }
219
gb_operation_set_data(struct gb_operation * operation,void * data)220 static inline void gb_operation_set_data(struct gb_operation *operation,
221 void *data)
222 {
223 operation->private = data;
224 }
225
226 int gb_operation_init(void);
227 void gb_operation_exit(void);
228
229 #endif /* !__OPERATION_H */
230