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_SPINLOCK_H_ 14 #include <sys/spinlock.h> 15 #endif 16 #include <machine/stdint.h> 17 18 struct lwkt_msg; 19 struct lwkt_port; 20 struct lwkt_serialize; 21 struct thread; 22 23 typedef struct lwkt_msg *lwkt_msg_t; 24 typedef struct lwkt_port *lwkt_port_t; 25 26 typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue; 27 28 /* 29 * The standard message and port structure for communications between 30 * threads. See kern/lwkt_msgport.c for documentation on how messages and 31 * ports work. 32 * 33 * A message may only be manipulated by whomever currently owns it, 34 * which generally means the originating port if the message has 35 * not been sent yet or has been replied, and the target port if the message 36 * has been sent and/or is undergoing processing. 37 * 38 * NOTE! 64-bit-align this structure. 39 */ 40 typedef struct lwkt_msg { 41 TAILQ_ENTRY(lwkt_msg) ms_node; /* link node */ 42 lwkt_port_t ms_target_port; /* current target or relay port */ 43 lwkt_port_t ms_reply_port; /* async replies returned here */ 44 void (*ms_abortfn)(struct lwkt_msg *); 45 int ms_flags; /* message flags */ 46 int ms_error; /* positive error code or 0 */ 47 union { 48 void *ms_resultp; /* misc pointer data or result */ 49 int ms_result; /* standard 'int'eger result */ 50 long ms_lresult; /* long result */ 51 int ms_fds[2]; /* two int bit results */ 52 __int32_t ms_result32; /* 32 bit result */ 53 __int64_t ms_result64; /* 64 bit result */ 54 __off_t ms_offset; /* off_t result */ 55 } u; 56 void (*ms_receiptfn)(struct lwkt_msg *, lwkt_port_t); 57 } lwkt_msg; 58 59 /* 60 * Message state flags are manipulated by the current owner only. 61 * 62 * DONE Indicates completion of the reply. This flag is also set 63 * for unsent messages. 64 * 65 * REPLY Indicates message is being replied but may or may not 66 * have been queued or returned yet. This bit is left set 67 * when a message is retrieved from a reply port so the caller 68 * can distinguish between requests and replies. 69 * 70 * QUEUED Indicates message is queued on reply or target port, or 71 * some other port. 72 * 73 * SYNC Indicates that the originator is blocked directly on the 74 * message and that the message should be signaled on 75 * completion instead of queued. 76 * 77 * INTRANSIT Indicates that the message state is indeterminant (e.g. 78 * being passed through an IPI). 79 * 80 * ABORTABLE Static flag indicates that ms_abortfn is valid. 81 * 82 * High 16 bits are available to message handlers. 83 */ 84 #define MSGF_DONE 0x0001 /* message is complete */ 85 #define MSGF_REPLY 0x0002 /* asynch message has been returned */ 86 #define MSGF_QUEUED 0x0004 /* message has been queued sanitychk */ 87 #define MSGF_SYNC 0x0008 /* synchronous message operation */ 88 #define MSGF_INTRANSIT 0x0010 /* in-transit (IPI) */ 89 #define MSGF_WAITING 0x0020 /* MSGF_SYNC being waited upon */ 90 #define MSGF_DROPABLE 0x0040 /* message supports drop */ 91 #define MSGF_ABORTABLE 0x0080 /* message supports abort */ 92 #define MSGF_PRIORITY 0x0100 /* priority message */ 93 #define MSGF_RECEIPT 0x0200 /* need receipt after put done */ 94 95 #define MSGF_USER0 0x00010000 96 #define MSGF_USER1 0x00020000 97 #define MSGF_USER2 0x00040000 98 #define MSGF_USER3 0x00080000 99 100 #define MSG_CMD_CDEV 0x00010000 101 #define MSG_CMD_VFS 0x00020000 102 #define MSG_CMD_SYSCALL 0x00030000 103 #define MSG_SUBCMD_MASK 0x0000FFFF 104 105 /* 106 * Notes on port processing requirements: 107 * 108 * mp_putport(): 109 * - may return synchronous error code (error != EASYNC) directly and 110 * does not need to check or set MSGF_DONE if so, or set ms_target_port 111 * - for asynch procesing should clear MSGF_DONE and set ms_target_port 112 * to port prior to initiation of the command. 113 * 114 * mp_waitmsg(): 115 * - wait for a particular message to be returned. 116 * 117 * mp_waitport(): 118 * - wait for a new message on the specified port. 119 * 120 * mp_replyport(): 121 * - reply a message (executed on the originating port to return a 122 * message to it). This can be rather involved if abort is to be 123 * supported, see lwkt_default_replyport(). Generally speaking 124 * one sets MSGF_DONE and MSGF_REPLY. If MSGF_SYNC is set the message 125 * is not queued to the port and the reply code wakes up the waiter 126 * directly. 127 * 128 * mp_dropmsg(): 129 * - drop a specific message from the specified port. Currently only 130 * threads' embedded ports (thread ports or spin ports) support this 131 * function and must be used in the port's owner thread. 132 * (returns 0 on success, ENOENT on error). 133 * 134 * The use of mpu_td and mp_u.spin is specific to the port callback function 135 * set. Default ports are tied to specific threads and use cpu locality 136 * of reference and mpu_td (and not mp_u.spin at all). Descriptor ports 137 * assume access via descriptors, signal interruption, etc. Such ports use 138 * mp_u.spin (and not mpu_td at all) and may be accessed by multiple threads. 139 * 140 * Threads' embedded ports always have mpu_td back pointing to themselves. 141 */ 142 typedef struct lwkt_port { 143 lwkt_msg_queue mp_msgq; 144 lwkt_msg_queue mp_msgq_prio; 145 int mp_flags; 146 int mp_cpuid; 147 union { 148 struct spinlock spin; 149 struct lwkt_serialize *serialize; 150 void *data; 151 } mp_u; 152 struct thread *mpu_td; 153 void * (*mp_getport)(lwkt_port_t); 154 int (*mp_putport)(lwkt_port_t, lwkt_msg_t); 155 int (*mp_waitmsg)(lwkt_msg_t, int flags); 156 void * (*mp_waitport)(lwkt_port_t, int flags); 157 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t); 158 int (*mp_dropmsg)(lwkt_port_t, lwkt_msg_t); 159 int (*mp_putport_oncpu)(lwkt_port_t, lwkt_msg_t); 160 } lwkt_port; 161 162 #ifdef _KERNEL 163 164 #include <sys/stdint.h> /* for boolean_t */ 165 166 #define mpu_spin mp_u.spin 167 #define mpu_serialize mp_u.serialize 168 #define mpu_data mp_u.data 169 170 /* 171 * Port state flags. 172 * 173 * WAITING The owner of the port is descheduled waiting for a message 174 * to be replied. In case this a spin port there can actually 175 * be more than one thread waiting on the port. 176 */ 177 #define MSGPORTF_WAITING 0x0001 178 179 /* 180 * These functions are good for userland as well as the kernel. The 181 * messaging function support for userland is provided by the kernel's 182 * kern/lwkt_msgport.c. The port functions are provided by userland. 183 */ 184 185 void lwkt_initport_thread(lwkt_port_t, struct thread *); 186 void lwkt_initport_spin(lwkt_port_t, struct thread *, boolean_t); 187 void lwkt_initport_serialize(lwkt_port_t, struct lwkt_serialize *); 188 void lwkt_initport_panic(lwkt_port_t); 189 void lwkt_initport_replyonly_null(lwkt_port_t); 190 void lwkt_initport_replyonly(lwkt_port_t, 191 void (*rportfn)(lwkt_port_t, lwkt_msg_t)); 192 void lwkt_initport_putonly(lwkt_port_t, 193 int (*pportfn)(lwkt_port_t, lwkt_msg_t)); 194 195 void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t); 196 void lwkt_sendmsg_oncpu(lwkt_port_t, lwkt_msg_t); 197 void lwkt_sendmsg_prepare(lwkt_port_t, lwkt_msg_t); 198 void lwkt_sendmsg_start(lwkt_port_t, lwkt_msg_t); 199 void lwkt_sendmsg_start_oncpu(lwkt_port_t, lwkt_msg_t); 200 int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int); 201 int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t); 202 void lwkt_abortmsg(lwkt_msg_t); 203 204 #endif /* _KERNEL */ 205 206 #endif 207