include/linux/greybus/operation.h

   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
 117 gb_operation_is_incoming(struct gb_operation *operation)
 118 {
 119         return operation->flags & GB_OPERATION_FLAG_INCOMING;
 120 }
 121
 122 static inline bool
 123 gb_operation_is_unidirectional(struct gb_operation *operation)
 124 {
 125         return operation->flags & GB_OPERATION_FLAG_UNIDIRECTIONAL;
 126 }
 127
 128 static inline bool
 129 gb_operation_short_response_allowed(struct gb_operation *operation)
 130 {
 131         return operation->flags & GB_OPERATION_FLAG_SHORT_RESPONSE;
 132 }
 133
 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 *
 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
 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
 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
 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
 215 static inline void *gb_operation_get_data(struct gb_operation *operation)
 216 {
 217         return operation->private;
 218 }
 219
 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 */