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Linux kernel mirror (for testing)
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linux
1/*
2 * Greybus operations
3 *
4 * Copyright 2014 Google Inc.
5 * Copyright 2014 Linaro Ltd.
6 *
7 * Released under the GPLv2 only.
8 */
9
10#ifndef __OPERATION_H
11#define __OPERATION_H
12
13#include <linux/completion.h>
14
15struct gb_operation;
16
17/* The default amount of time a request is given to complete */
18#define GB_OPERATION_TIMEOUT_DEFAULT 1000 /* milliseconds */
19
20/*
21 * The top bit of the type in an operation message header indicates
22 * whether the message is a request (bit clear) or response (bit set)
23 */
24#define GB_MESSAGE_TYPE_RESPONSE ((u8)0x80)
25
26enum gb_operation_result {
27 GB_OP_SUCCESS = 0x00,
28 GB_OP_INTERRUPTED = 0x01,
29 GB_OP_TIMEOUT = 0x02,
30 GB_OP_NO_MEMORY = 0x03,
31 GB_OP_PROTOCOL_BAD = 0x04,
32 GB_OP_OVERFLOW = 0x05,
33 GB_OP_INVALID = 0x06,
34 GB_OP_RETRY = 0x07,
35 GB_OP_NONEXISTENT = 0x08,
36 GB_OP_UNKNOWN_ERROR = 0xfe,
37 GB_OP_MALFUNCTION = 0xff,
38};
39
40#define GB_OPERATION_MESSAGE_SIZE_MIN sizeof(struct gb_operation_msg_hdr)
41#define GB_OPERATION_MESSAGE_SIZE_MAX U16_MAX
42
43/*
44 * Protocol code should only examine the payload and payload_size fields, and
45 * host-controller drivers may use the hcpriv field. All other fields are
46 * intended to be private to the operations core code.
47 */
48struct gb_message {
49 struct gb_operation *operation;
50 struct gb_operation_msg_hdr *header;
51
52 void *payload;
53 size_t payload_size;
54
55 void *buffer;
56
57 void *hcpriv;
58};
59
60#define GB_OPERATION_FLAG_INCOMING BIT(0)
61#define GB_OPERATION_FLAG_UNIDIRECTIONAL BIT(1)
62#define GB_OPERATION_FLAG_SHORT_RESPONSE BIT(2)
63#define GB_OPERATION_FLAG_CORE BIT(3)
64
65#define GB_OPERATION_FLAG_USER_MASK (GB_OPERATION_FLAG_SHORT_RESPONSE | \
66 GB_OPERATION_FLAG_UNIDIRECTIONAL)
67
68/*
69 * A Greybus operation is a remote procedure call performed over a
70 * connection between two UniPro interfaces.
71 *
72 * Every operation consists of a request message sent to the other
73 * end of the connection coupled with a reply message returned to
74 * the sender. Every operation has a type, whose interpretation is
75 * dependent on the protocol associated with the connection.
76 *
77 * Only four things in an operation structure are intended to be
78 * directly usable by protocol handlers: the operation's connection
79 * pointer; the operation type; the request message payload (and
80 * size); and the response message payload (and size). Note that a
81 * message with a 0-byte payload has a null message payload pointer.
82 *
83 * In addition, every operation has a result, which is an errno
84 * value. Protocol handlers access the operation result using
85 * gb_operation_result().
86 */
87typedef void (*gb_operation_callback)(struct gb_operation *);
88struct gb_operation {
89 struct gb_connection *connection;
90 struct gb_message *request;
91 struct gb_message *response;
92
93 unsigned long flags;
94 u8 type;
95 u16 id;
96 int errno; /* Operation result */
97
98 struct work_struct work;
99 gb_operation_callback callback;
100 struct completion completion;
101
102 struct kref kref;
103 atomic_t waiters;
104
105 int active;
106 struct list_head links; /* connection->operations */
107};
108
109static inline bool
110gb_operation_is_incoming(struct gb_operation *operation)
111{
112 return operation->flags & GB_OPERATION_FLAG_INCOMING;
113}
114
115static inline bool
116gb_operation_is_unidirectional(struct gb_operation *operation)
117{
118 return operation->flags & GB_OPERATION_FLAG_UNIDIRECTIONAL;
119}
120
121static inline bool
122gb_operation_short_response_allowed(struct gb_operation *operation)
123{
124 return operation->flags & GB_OPERATION_FLAG_SHORT_RESPONSE;
125}
126
127static inline bool gb_operation_is_core(struct gb_operation *operation)
128{
129 return operation->flags & GB_OPERATION_FLAG_CORE;
130}
131
132void gb_connection_recv(struct gb_connection *connection,
133 void *data, size_t size);
134
135int gb_operation_result(struct gb_operation *operation);
136
137size_t gb_operation_get_payload_size_max(struct gb_connection *connection);
138struct gb_operation *
139gb_operation_create_flags(struct gb_connection *connection,
140 u8 type, size_t request_size,
141 size_t response_size, unsigned long flags,
142 gfp_t gfp);
143
144static inline struct gb_operation *
145gb_operation_create(struct gb_connection *connection,
146 u8 type, size_t request_size,
147 size_t response_size, gfp_t gfp)
148{
149 return gb_operation_create_flags(connection, type, request_size,
150 response_size, 0, gfp);
151}
152
153struct gb_operation *
154gb_operation_create_core(struct gb_connection *connection,
155 u8 type, size_t request_size,
156 size_t response_size, unsigned long flags,
157 gfp_t gfp);
158
159void gb_operation_get(struct gb_operation *operation);
160void gb_operation_put(struct gb_operation *operation);
161
162bool gb_operation_response_alloc(struct gb_operation *operation,
163 size_t response_size, gfp_t gfp);
164
165int gb_operation_request_send(struct gb_operation *operation,
166 gb_operation_callback callback,
167 gfp_t gfp);
168int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
169 unsigned int timeout);
170static inline int
171gb_operation_request_send_sync(struct gb_operation *operation)
172{
173 return gb_operation_request_send_sync_timeout(operation,
174 GB_OPERATION_TIMEOUT_DEFAULT);
175}
176
177void gb_operation_cancel(struct gb_operation *operation, int errno);
178void gb_operation_cancel_incoming(struct gb_operation *operation, int errno);
179
180void greybus_message_sent(struct gb_host_device *hd,
181 struct gb_message *message, int status);
182
183int gb_operation_sync_timeout(struct gb_connection *connection, int type,
184 void *request, int request_size,
185 void *response, int response_size,
186 unsigned int timeout);
187int gb_operation_unidirectional_timeout(struct gb_connection *connection,
188 int type, void *request, int request_size,
189 unsigned int timeout);
190
191static inline int gb_operation_sync(struct gb_connection *connection, int type,
192 void *request, int request_size,
193 void *response, int response_size)
194{
195 return gb_operation_sync_timeout(connection, type,
196 request, request_size, response, response_size,
197 GB_OPERATION_TIMEOUT_DEFAULT);
198}
199
200static inline int gb_operation_unidirectional(struct gb_connection *connection,
201 int type, void *request, int request_size)
202{
203 return gb_operation_unidirectional_timeout(connection, type,
204 request, request_size, GB_OPERATION_TIMEOUT_DEFAULT);
205}
206
207int gb_operation_init(void);
208void gb_operation_exit(void);
209
210#endif /* !__OPERATION_H */