4 * Implements LWKT messages and ports.
6 * $DragonFly: src/sys/sys/msgport.h,v 1.32 2008/11/26 15:05:42 sephe Exp $
9 #ifndef _SYS_MSGPORT_H_
10 #define _SYS_MSGPORT_H_
13 #include <sys/queue.h> /* TAILQ_* macros */
15 #ifndef _SYS_STDINT_H_
16 #include <sys/stdint.h>
18 #ifndef _SYS_SPINLOCK_H_
19 #include <sys/spinlock.h>
24 #ifndef _SYS_MALLOC_H_
25 #include <sys/malloc.h>
32 struct lwkt_serialize;
35 typedef struct lwkt_msg *lwkt_msg_t;
36 typedef struct lwkt_port *lwkt_port_t;
38 typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue;
41 * The standard message and port structure for communications between
42 * threads. See kern/lwkt_msgport.c for documentation on how messages and
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.
50 * NOTE! 64-bit-align this structure.
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 */
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 */
68 int ms_pad[2]; /* future use */
72 * Message state flags are manipulated by the current owner only.
74 * DONE Indicates completion of the reply. This flag is also set
75 * for unsent messages.
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.
82 * QUEUED Indicates message is queued on reply or target port, or
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.
89 * INTRANSIT Indicates that the message state is indeterminant (e.g.
90 * being passed through an IPI).
92 * ABORTABLE Static flag indicates that ms_abortfn is valid.
94 * High 16 bits are available to message handlers.
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 */
106 #define MSGF_USER0 0x00010000
107 #define MSGF_USER1 0x00020000
108 #define MSGF_USER2 0x00040000
109 #define MSGF_USER3 0x00080000
111 #define MSG_CMD_CDEV 0x00010000
112 #define MSG_CMD_VFS 0x00020000
113 #define MSG_CMD_SYSCALL 0x00030000
114 #define MSG_SUBCMD_MASK 0x0000FFFF
117 MALLOC_DECLARE(M_LWKTMSG);
121 * Notes on port processing requirements:
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.
130 * - wait for a particular message to be returned.
133 * - wait for a new message on the specified port.
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
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).
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.
155 * Threads' embedded ports always have mpu_td back pointing to themselves.
157 typedef struct lwkt_port {
158 lwkt_msg_queue mp_msgq;
159 lwkt_msg_queue mp_msgq_prio;
162 struct spinlock spin;
163 struct lwkt_serialize *serialize;
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);
177 #define mpu_spin mp_u.spin
178 #define mpu_serialize mp_u.serialize
179 #define mpu_data mp_u.data
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.
190 #define MSGPORTF_WAITING 0x0001
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.
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));
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);