| 1 | /* |
| 2 | * SYS/MSGPORT.H |
| 3 | * |
| 4 | * Implements LWKT messages and ports. |
| 5 | * |
| 6 | * $DragonFly: src/sys/sys/msgport.h,v 1.28 2008/08/25 23:34:34 dillon 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_ABORTABLE 0x0080 /* message supports abort */ |
| 102 | |
| 103 | #define MSGF_USER0 0x00010000 |
| 104 | #define MSGF_USER1 0x00020000 |
| 105 | #define MSGF_USER2 0x00040000 |
| 106 | #define MSGF_USER3 0x00080000 |
| 107 | |
| 108 | #define MSG_CMD_CDEV 0x00010000 |
| 109 | #define MSG_CMD_VFS 0x00020000 |
| 110 | #define MSG_CMD_SYSCALL 0x00030000 |
| 111 | #define MSG_SUBCMD_MASK 0x0000FFFF |
| 112 | |
| 113 | #ifdef _KERNEL |
| 114 | MALLOC_DECLARE(M_LWKTMSG); |
| 115 | #endif |
| 116 | |
| 117 | /* |
| 118 | * Notes on port processing requirements: |
| 119 | * |
| 120 | * mp_putport(): |
| 121 | * - may return synchronous error code (error != EASYNC) directly and |
| 122 | * does not need to check or set MSGF_DONE if so, or set ms_target_port |
| 123 | * - for asynch procesing should clear MSGF_DONE and set ms_target_port |
| 124 | * to port prior to initiation of the command. |
| 125 | * |
| 126 | * mp_waitmsg(): |
| 127 | * - wait for a particular message to be returned. |
| 128 | * |
| 129 | * mp_waitport(): |
| 130 | * - wait for a new message on the specified port. |
| 131 | * |
| 132 | * mp_replyport(): |
| 133 | * - reply a message (executed on the originating port to return a |
| 134 | * message to it). This can be rather involved if abort is to be |
| 135 | * supported, see lwkt_default_replyport(). Generally speaking |
| 136 | * one sets MSGF_DONE. If MSGF_SYNC is set the message is not |
| 137 | * queued to the port and the reply code wakes up the waiter |
| 138 | * directly. |
| 139 | * |
| 140 | * The use of mp_u.td and mp_u.spin is specific to the port callback function |
| 141 | * set. Default ports are tied to specific threads and use cpu locality |
| 142 | * of reference and mp_u.td (and not mp_u.spin at all). Descriptor ports |
| 143 | * assume access via descriptors, signal interruption, etc. Such ports use |
| 144 | * mp_u.spin (and not mp_u.td at all) and may be accessed by multiple threads. |
| 145 | */ |
| 146 | typedef struct lwkt_port { |
| 147 | lwkt_msg_queue mp_msgq; |
| 148 | int mp_flags; |
| 149 | union { |
| 150 | struct spinlock spin; |
| 151 | struct thread *td; |
| 152 | struct lwkt_serialize *serialize; |
| 153 | void *data; |
| 154 | } mp_u; |
| 155 | void * (*mp_getport)(lwkt_port_t); |
| 156 | int (*mp_putport)(lwkt_port_t, lwkt_msg_t); |
| 157 | int (*mp_waitmsg)(lwkt_msg_t, int flags); |
| 158 | void * (*mp_waitport)(lwkt_port_t, int flags); |
| 159 | void (*mp_replyport)(lwkt_port_t, lwkt_msg_t); |
| 160 | } lwkt_port; |
| 161 | |
| 162 | #ifdef _KERNEL |
| 163 | |
| 164 | #define mpu_td mp_u.td |
| 165 | #define mpu_spin mp_u.spin |
| 166 | #define mpu_serialize mp_u.serialize |
| 167 | #define mpu_data mp_u.data |
| 168 | |
| 169 | #endif |
| 170 | |
| 171 | #define MSGPORTF_WAITING 0x0001 |
| 172 | |
| 173 | /* |
| 174 | * These functions are good for userland as well as the kernel. The |
| 175 | * messaging function support for userland is provided by the kernel's |
| 176 | * kern/lwkt_msgport.c. The port functions are provided by userland. |
| 177 | */ |
| 178 | |
| 179 | void lwkt_initport_thread(lwkt_port_t, struct thread *); |
| 180 | void lwkt_initport_spin(lwkt_port_t); |
| 181 | void lwkt_initport_serialize(lwkt_port_t, struct lwkt_serialize *); |
| 182 | void lwkt_initport_panic(lwkt_port_t); |
| 183 | void lwkt_initport_replyonly_null(lwkt_port_t); |
| 184 | void lwkt_initport_replyonly(lwkt_port_t, |
| 185 | void (*rportfn)(lwkt_port_t, lwkt_msg_t)); |
| 186 | void lwkt_initport_putonly(lwkt_port_t, |
| 187 | int (*pportfn)(lwkt_port_t, lwkt_msg_t)); |
| 188 | |
| 189 | void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t); |
| 190 | int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int); |
| 191 | int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t); |
| 192 | void lwkt_abortmsg(lwkt_msg_t); |
| 193 | |
| 194 | #endif |