1 /* 2 * SYS/MSGPORT.H 3 * 4 * Implements LWKT messages and ports. 5 * 6 * $DragonFly: src/sys/sys/msgport.h,v 1.32 2008/11/26 15:05:42 sephe Exp $ 7 */ 8 9 #ifndef _SYS_MSGPORT_H_ 10 #define _SYS_MSGPORT_H_ 11 12 #ifndef _SYS_QUEUE_H_ 13 #include <sys/queue.h> /* TAILQ_* macros */ 14 #endif 15 #ifndef _SYS_STDINT_H_ 16 #include <sys/stdint.h> 17 #endif 18 #ifndef _SYS_SPINLOCK_H_ 19 #include <sys/spinlock.h> 20 #endif 21 22 #ifdef _KERNEL 23 24 #ifndef _SYS_MALLOC_H_ 25 #include <sys/malloc.h> 26 #endif 27 28 #endif 29 30 struct lwkt_msg; 31 struct lwkt_port; 32 struct lwkt_serialize; 33 struct thread; 34 35 typedef struct lwkt_msg *lwkt_msg_t; 36 typedef struct lwkt_port *lwkt_port_t; 37 38 typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue; 39 40 /* 41 * The standard message and port structure for communications between 42 * threads. See kern/lwkt_msgport.c for documentation on how messages and 43 * ports work. 44 * 45 * A message may only be manipulated by whomever currently owns it, 46 * which generally means the originating port if the message has 47 * not been sent yet or has been replied, and the target port if the message 48 * has been sent and/or is undergoing processing. 49 * 50 * NOTE! 64-bit-align this structure. 51 */ 52 typedef struct lwkt_msg { 53 TAILQ_ENTRY(lwkt_msg) ms_node; /* link node */ 54 lwkt_port_t ms_target_port; /* current target or relay port */ 55 lwkt_port_t ms_reply_port; /* async replies returned here */ 56 void (*ms_abortfn)(struct lwkt_msg *); 57 int ms_flags; /* message flags */ 58 int ms_error; /* positive error code or 0 */ 59 union { 60 void *ms_resultp; /* misc pointer data or result */ 61 int ms_result; /* standard 'int'eger result */ 62 long ms_lresult; /* long result */ 63 int ms_fds[2]; /* two int bit results */ 64 __int32_t ms_result32; /* 32 bit result */ 65 __int64_t ms_result64; /* 64 bit result */ 66 __off_t ms_offset; /* off_t result */ 67 } u; 68 int ms_pad[2]; /* future use */ 69 } lwkt_msg; 70 71 /* 72 * Message state flags are manipulated by the current owner only. 73 * 74 * DONE Indicates completion of the reply. This flag is also set 75 * for unsent messages. 76 * 77 * REPLY Indicates message is being replied but may or may not 78 * have been queued or returned yet. This bit is left set 79 * when a message is retrieved from a reply port so the caller 80 * can distinguish between requests and replies. 81 * 82 * QUEUED Indicates message is queued on reply or target port, or 83 * some other port. 84 * 85 * SYNC Indicates that the originator is blocked directly on the 86 * message and that the message should be signaled on 87 * completion instead of queued. 88 * 89 * INTRANSIT Indicates that the message state is indeterminant (e.g. 90 * being passed through an IPI). 91 * 92 * ABORTABLE Static flag indicates that ms_abortfn is valid. 93 * 94 * High 16 bits are available to message handlers. 95 */ 96 #define MSGF_DONE 0x0001 /* message is complete */ 97 #define MSGF_REPLY 0x0002 /* asynch message has been returned */ 98 #define MSGF_QUEUED 0x0004 /* message has been queued sanitychk */ 99 #define MSGF_SYNC 0x0008 /* synchronous message operation */ 100 #define MSGF_INTRANSIT 0x0010 /* in-transit (IPI) */ 101 #define MSGF_WAITING 0x0020 /* MSGF_SYNC being waited upon */ 102 #define MSGF_DROPABLE 0x0040 /* message supports drop */ 103 #define MSGF_ABORTABLE 0x0080 /* message supports abort */ 104 #define MSGF_PRIORITY 0x0100 /* priority message */ 105 106 #define MSGF_USER0 0x00010000 107 #define MSGF_USER1 0x00020000 108 #define MSGF_USER2 0x00040000 109 #define MSGF_USER3 0x00080000 110 111 #define MSG_CMD_CDEV 0x00010000 112 #define MSG_CMD_VFS 0x00020000 113 #define MSG_CMD_SYSCALL 0x00030000 114 #define MSG_SUBCMD_MASK 0x0000FFFF 115 116 #ifdef _KERNEL 117 MALLOC_DECLARE(M_LWKTMSG); 118 #endif 119 120 /* 121 * Notes on port processing requirements: 122 * 123 * mp_putport(): 124 * - may return synchronous error code (error != EASYNC) directly and 125 * does not need to check or set MSGF_DONE if so, or set ms_target_port 126 * - for asynch procesing should clear MSGF_DONE and set ms_target_port 127 * to port prior to initiation of the command. 128 * 129 * mp_waitmsg(): 130 * - wait for a particular message to be returned. 131 * 132 * mp_waitport(): 133 * - wait for a new message on the specified port. 134 * 135 * mp_replyport(): 136 * - reply a message (executed on the originating port to return a 137 * message to it). This can be rather involved if abort is to be 138 * supported, see lwkt_default_replyport(). Generally speaking 139 * one sets MSGF_DONE and MSGF_REPLY. If MSGF_SYNC is set the message 140 * is not queued to the port and the reply code wakes up the waiter 141 * directly. 142 * 143 * mp_dropmsg(): 144 * - drop a specific message from the specified port. Currently only 145 * threads' embedded ports (thread ports or spin ports) support this 146 * function and must be used in the port's owner thread. 147 * (returns 0 on success, ENOENT on error). 148 * 149 * The use of mpu_td and mp_u.spin is specific to the port callback function 150 * set. Default ports are tied to specific threads and use cpu locality 151 * of reference and mpu_td (and not mp_u.spin at all). Descriptor ports 152 * assume access via descriptors, signal interruption, etc. Such ports use 153 * mp_u.spin (and not mpu_td at all) and may be accessed by multiple threads. 154 * 155 * Threads' embedded ports always have mpu_td back pointing to themselves. 156 */ 157 typedef struct lwkt_port { 158 lwkt_msg_queue mp_msgq; 159 lwkt_msg_queue mp_msgq_prio; 160 int mp_flags; 161 union { 162 struct spinlock spin; 163 struct lwkt_serialize *serialize; 164 void *data; 165 } mp_u; 166 struct thread *mpu_td; 167 void * (*mp_getport)(lwkt_port_t); 168 int (*mp_putport)(lwkt_port_t, lwkt_msg_t); 169 int (*mp_waitmsg)(lwkt_msg_t, int flags); 170 void * (*mp_waitport)(lwkt_port_t, int flags); 171 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t); 172 int (*mp_dropmsg)(lwkt_port_t, lwkt_msg_t); 173 } lwkt_port; 174 175 #ifdef _KERNEL 176 177 #define mpu_spin mp_u.spin 178 #define mpu_serialize mp_u.serialize 179 #define mpu_data mp_u.data 180 181 #endif 182 183 /* 184 * Port state flags. 185 * 186 * WAITING The owner of the port is descheduled waiting for a message 187 * to be replied. In case this a spin port there can actually 188 * be more than one thread waiting on the port. 189 */ 190 #define MSGPORTF_WAITING 0x0001 191 192 /* 193 * These functions are good for userland as well as the kernel. The 194 * messaging function support for userland is provided by the kernel's 195 * kern/lwkt_msgport.c. The port functions are provided by userland. 196 */ 197 198 void lwkt_initport_thread(lwkt_port_t, struct thread *); 199 void lwkt_initport_spin(lwkt_port_t, struct thread *); 200 void lwkt_initport_serialize(lwkt_port_t, struct lwkt_serialize *); 201 void lwkt_initport_panic(lwkt_port_t); 202 void lwkt_initport_replyonly_null(lwkt_port_t); 203 void lwkt_initport_replyonly(lwkt_port_t, 204 void (*rportfn)(lwkt_port_t, lwkt_msg_t)); 205 void lwkt_initport_putonly(lwkt_port_t, 206 int (*pportfn)(lwkt_port_t, lwkt_msg_t)); 207 208 void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t); 209 void lwkt_sendmsg_stage1(lwkt_port_t, lwkt_msg_t); 210 void lwkt_sendmsg_stage2(lwkt_port_t, lwkt_msg_t); 211 int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int); 212 int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t); 213 void lwkt_abortmsg(lwkt_msg_t); 214 215 #endif 216