1 /* 2 * SYS/MSGPORT.H 3 * 4 * Implements LWKT messages and ports. 5 * 6 * $DragonFly: src/sys/sys/msgport.h,v 1.27 2008/03/05 13:03:29 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 #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_ABORTABLE 0x0080 /* message supports abort */ 100 101 #define MSG_CMD_CDEV 0x00010000 102 #define MSG_CMD_VFS 0x00020000 103 #define MSG_CMD_SYSCALL 0x00030000 104 #define MSG_SUBCMD_MASK 0x0000FFFF 105 106 #ifdef _KERNEL 107 MALLOC_DECLARE(M_LWKTMSG); 108 #endif 109 110 /* 111 * Notes on port processing requirements: 112 * 113 * mp_putport(): 114 * - may return synchronous error code (error != EASYNC) directly and 115 * does not need to check or set MSGF_DONE if so, or set ms_target_port 116 * - for asynch procesing should clear MSGF_DONE and set ms_target_port 117 * to port prior to initiation of the command. 118 * 119 * mp_waitmsg(): 120 * - wait for a particular message to be returned. 121 * 122 * mp_waitport(): 123 * - wait for a new message on the specified port. 124 * 125 * mp_replyport(): 126 * - reply a message (executed on the originating port to return a 127 * message to it). This can be rather involved if abort is to be 128 * supported, see lwkt_default_replyport(). Generally speaking 129 * one sets MSGF_DONE. If MSGF_SYNC is set the message is not 130 * queued to the port and the reply code wakes up the waiter 131 * directly. 132 * 133 * The use of mp_u.td and mp_u.spin is specific to the port callback function 134 * set. Default ports are tied to specific threads and use cpu locality 135 * of reference and mp_u.td (and not mp_u.spin at all). Descriptor ports 136 * assume access via descriptors, signal interruption, etc. Such ports use 137 * mp_u.spin (and not mp_u.td at all) and may be accessed by multiple threads. 138 */ 139 typedef struct lwkt_port { 140 lwkt_msg_queue mp_msgq; 141 int mp_flags; 142 union { 143 struct spinlock spin; 144 struct thread *td; 145 struct lwkt_serialize *serialize; 146 void *data; 147 } mp_u; 148 void * (*mp_getport)(lwkt_port_t); 149 int (*mp_putport)(lwkt_port_t, lwkt_msg_t); 150 int (*mp_waitmsg)(lwkt_msg_t, int flags); 151 void * (*mp_waitport)(lwkt_port_t, int flags); 152 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t); 153 } lwkt_port; 154 155 #ifdef _KERNEL 156 157 #define mpu_td mp_u.td 158 #define mpu_spin mp_u.spin 159 #define mpu_serialize mp_u.serialize 160 #define mpu_data mp_u.data 161 162 #endif 163 164 #define MSGPORTF_WAITING 0x0001 165 166 /* 167 * These functions are good for userland as well as the kernel. The 168 * messaging function support for userland is provided by the kernel's 169 * kern/lwkt_msgport.c. The port functions are provided by userland. 170 */ 171 172 void lwkt_initport_thread(lwkt_port_t, struct thread *); 173 void lwkt_initport_spin(lwkt_port_t); 174 void lwkt_initport_serialize(lwkt_port_t, struct lwkt_serialize *); 175 void lwkt_initport_panic(lwkt_port_t); 176 void lwkt_initport_replyonly_null(lwkt_port_t); 177 void lwkt_initport_replyonly(lwkt_port_t, 178 void (*rportfn)(lwkt_port_t, lwkt_msg_t)); 179 void lwkt_initport_putonly(lwkt_port_t, 180 int (*pportfn)(lwkt_port_t, lwkt_msg_t)); 181 182 void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t); 183 int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int); 184 int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t); 185 void lwkt_abortmsg(lwkt_msg_t); 186 187 #endif 188