1 /* 2 * SYS/MSGPORT.H 3 * 4 * Implements LWKT messages and ports. 5 */ 6 7 #ifndef _SYS_MSGPORT_H_ 8 #define _SYS_MSGPORT_H_ 9 10 #ifndef _SYS_QUEUE_H_ 11 #include <sys/queue.h> /* TAILQ_* macros */ 12 #endif 13 #ifndef _SYS_STDINT_H_ 14 #include <sys/stdint.h> 15 #endif 16 #ifndef _SYS_SPINLOCK_H_ 17 #include <sys/spinlock.h> 18 #endif 19 20 #ifdef _KERNEL 21 22 #ifndef _SYS_MALLOC_H_ 23 #include <sys/malloc.h> 24 #endif 25 26 #endif 27 28 struct lwkt_msg; 29 struct lwkt_port; 30 struct lwkt_serialize; 31 struct thread; 32 33 typedef struct lwkt_msg *lwkt_msg_t; 34 typedef struct lwkt_port *lwkt_port_t; 35 36 typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue; 37 38 /* 39 * The standard message and port structure for communications between 40 * threads. See kern/lwkt_msgport.c for documentation on how messages and 41 * ports work. 42 * 43 * A message may only be manipulated by whomever currently owns it, 44 * which generally means the originating port if the message has 45 * not been sent yet or has been replied, and the target port if the message 46 * has been sent and/or is undergoing processing. 47 * 48 * NOTE! 64-bit-align this structure. 49 */ 50 typedef struct lwkt_msg { 51 TAILQ_ENTRY(lwkt_msg) ms_node; /* link node */ 52 lwkt_port_t ms_target_port; /* current target or relay port */ 53 lwkt_port_t ms_reply_port; /* async replies returned here */ 54 void (*ms_abortfn)(struct lwkt_msg *); 55 int ms_flags; /* message flags */ 56 int ms_error; /* positive error code or 0 */ 57 union { 58 void *ms_resultp; /* misc pointer data or result */ 59 int ms_result; /* standard 'int'eger result */ 60 long ms_lresult; /* long result */ 61 int ms_fds[2]; /* two int bit results */ 62 __int32_t ms_result32; /* 32 bit result */ 63 __int64_t ms_result64; /* 64 bit result */ 64 __off_t ms_offset; /* off_t result */ 65 } u; 66 int ms_pad[2]; /* future use */ 67 } lwkt_msg; 68 69 /* 70 * Message state flags are manipulated by the current owner only. 71 * 72 * DONE Indicates completion of the reply. This flag is also set 73 * for unsent messages. 74 * 75 * REPLY Indicates message is being replied but may or may not 76 * have been queued or returned yet. This bit is left set 77 * when a message is retrieved from a reply port so the caller 78 * can distinguish between requests and replies. 79 * 80 * QUEUED Indicates message is queued on reply or target port, or 81 * some other port. 82 * 83 * SYNC Indicates that the originator is blocked directly on the 84 * message and that the message should be signaled on 85 * completion instead of queued. 86 * 87 * INTRANSIT Indicates that the message state is indeterminant (e.g. 88 * being passed through an IPI). 89 * 90 * ABORTABLE Static flag indicates that ms_abortfn is valid. 91 * 92 * High 16 bits are available to message handlers. 93 */ 94 #define MSGF_DONE 0x0001 /* message is complete */ 95 #define MSGF_REPLY 0x0002 /* asynch message has been returned */ 96 #define MSGF_QUEUED 0x0004 /* message has been queued sanitychk */ 97 #define MSGF_SYNC 0x0008 /* synchronous message operation */ 98 #define MSGF_INTRANSIT 0x0010 /* in-transit (IPI) */ 99 #define MSGF_WAITING 0x0020 /* MSGF_SYNC being waited upon */ 100 #define MSGF_DROPABLE 0x0040 /* message supports drop */ 101 #define MSGF_ABORTABLE 0x0080 /* message supports abort */ 102 #define MSGF_PRIORITY 0x0100 /* priority message */ 103 104 #define MSGF_USER0 0x00010000 105 #define MSGF_USER1 0x00020000 106 #define MSGF_USER2 0x00040000 107 #define MSGF_USER3 0x00080000 108 109 #define MSG_CMD_CDEV 0x00010000 110 #define MSG_CMD_VFS 0x00020000 111 #define MSG_CMD_SYSCALL 0x00030000 112 #define MSG_SUBCMD_MASK 0x0000FFFF 113 114 #ifdef _KERNEL 115 MALLOC_DECLARE(M_LWKTMSG); 116 #endif 117 118 /* 119 * Notes on port processing requirements: 120 * 121 * mp_putport(): 122 * - may return synchronous error code (error != EASYNC) directly and 123 * does not need to check or set MSGF_DONE if so, or set ms_target_port 124 * - for asynch procesing should clear MSGF_DONE and set ms_target_port 125 * to port prior to initiation of the command. 126 * 127 * mp_waitmsg(): 128 * - wait for a particular message to be returned. 129 * 130 * mp_waitport(): 131 * - wait for a new message on the specified port. 132 * 133 * mp_replyport(): 134 * - reply a message (executed on the originating port to return a 135 * message to it). This can be rather involved if abort is to be 136 * supported, see lwkt_default_replyport(). Generally speaking 137 * one sets MSGF_DONE and MSGF_REPLY. If MSGF_SYNC is set the message 138 * is not queued to the port and the reply code wakes up the waiter 139 * directly. 140 * 141 * mp_dropmsg(): 142 * - drop a specific message from the specified port. Currently only 143 * threads' embedded ports (thread ports or spin ports) support this 144 * function and must be used in the port's owner thread. 145 * (returns 0 on success, ENOENT on error). 146 * 147 * The use of mpu_td and mp_u.spin is specific to the port callback function 148 * set. Default ports are tied to specific threads and use cpu locality 149 * of reference and mpu_td (and not mp_u.spin at all). Descriptor ports 150 * assume access via descriptors, signal interruption, etc. Such ports use 151 * mp_u.spin (and not mpu_td at all) and may be accessed by multiple threads. 152 * 153 * Threads' embedded ports always have mpu_td back pointing to themselves. 154 */ 155 typedef struct lwkt_port { 156 lwkt_msg_queue mp_msgq; 157 lwkt_msg_queue mp_msgq_prio; 158 int mp_flags; 159 int mp_cpuid; 160 union { 161 struct spinlock spin; 162 struct lwkt_serialize *serialize; 163 void *data; 164 } mp_u; 165 struct thread *mpu_td; 166 void * (*mp_getport)(lwkt_port_t); 167 int (*mp_putport)(lwkt_port_t, lwkt_msg_t); 168 int (*mp_waitmsg)(lwkt_msg_t, int flags); 169 void * (*mp_waitport)(lwkt_port_t, int flags); 170 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t); 171 int (*mp_dropmsg)(lwkt_port_t, lwkt_msg_t); 172 int (*mp_putport_oncpu)(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 /* 182 * Port state flags. 183 * 184 * WAITING The owner of the port is descheduled waiting for a message 185 * to be replied. In case this a spin port there can actually 186 * be more than one thread waiting on the port. 187 */ 188 #define MSGPORTF_WAITING 0x0001 189 190 /* 191 * These functions are good for userland as well as the kernel. The 192 * messaging function support for userland is provided by the kernel's 193 * kern/lwkt_msgport.c. The port functions are provided by userland. 194 */ 195 196 void lwkt_initport_thread(lwkt_port_t, struct thread *); 197 void lwkt_initport_spin(lwkt_port_t, struct thread *, boolean_t); 198 void lwkt_initport_serialize(lwkt_port_t, struct lwkt_serialize *); 199 void lwkt_initport_panic(lwkt_port_t); 200 void lwkt_initport_replyonly_null(lwkt_port_t); 201 void lwkt_initport_replyonly(lwkt_port_t, 202 void (*rportfn)(lwkt_port_t, lwkt_msg_t)); 203 void lwkt_initport_putonly(lwkt_port_t, 204 int (*pportfn)(lwkt_port_t, lwkt_msg_t)); 205 206 void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t); 207 void lwkt_sendmsg_oncpu(lwkt_port_t, lwkt_msg_t); 208 void lwkt_sendmsg_prepare(lwkt_port_t, lwkt_msg_t); 209 void lwkt_sendmsg_start(lwkt_port_t, lwkt_msg_t); 210 int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int); 211 int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t); 212 void lwkt_abortmsg(lwkt_msg_t); 213 214 #endif /* _KERNEL */ 215 216 #endif 217