4 * Implements LWKT messages and ports.
6 * $DragonFly: src/sys/sys/msgport.h,v 1.26 2007/05/24 20:51:19 dillon 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>
34 typedef struct lwkt_msg *lwkt_msg_t;
35 typedef struct lwkt_port *lwkt_port_t;
37 typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue;
40 * The standard message and port structure for communications between
41 * threads. See kern/lwkt_msgport.c for documentation on how messages and
44 * A message may only be manipulated by whomever currently owns it,
45 * which generally means the originating port if the message has
46 * not been sent yet or has been replied, and the target port if the message
47 * has been sent and/or is undergoing processing.
49 * NOTE! 64-bit-align this structure.
51 typedef struct lwkt_msg {
52 TAILQ_ENTRY(lwkt_msg) ms_node; /* link node */
53 lwkt_port_t ms_target_port; /* current target or relay port */
54 lwkt_port_t ms_reply_port; /* async replies returned here */
55 void (*ms_abortfn)(struct lwkt_msg *);
56 int ms_flags; /* message flags */
57 int ms_error; /* positive error code or 0 */
59 void *ms_resultp; /* misc pointer data or result */
60 int ms_result; /* standard 'int'eger result */
61 long ms_lresult; /* long result */
62 int ms_fds[2]; /* two int bit results */
63 __int32_t ms_result32; /* 32 bit result */
64 __int64_t ms_result64; /* 64 bit result */
65 __off_t ms_offset; /* off_t result */
67 int ms_pad[2]; /* future use */
71 * Message state flags are manipulated by the current owner only.
73 * DONE Indicates completion of the reply. This flag is also set
74 * for unsent messages.
76 * REPLY Indicates message is being replied but may or may not
77 * have been queued or returned yet. This bit is left set
78 * when a message is retrieved from a reply port so the caller
79 * can distinguish between requests and replies.
81 * QUEUED Indicates message is queued on reply or target port, or
84 * SYNC Indicates that the originator is blocked directly on the
85 * message and that the message should be signaled on
86 * completion instead of queued.
88 * INTRANSIT Indicates that the message state is indeterminant (e.g.
89 * being passed through an IPI).
91 * ABORTABLE Static flag indicates that ms_abortfn is valid.
93 #define MSGF_DONE 0x0001 /* message is complete */
94 #define MSGF_REPLY 0x0002 /* asynch message has been returned */
95 #define MSGF_QUEUED 0x0004 /* message has been queued sanitychk */
96 #define MSGF_SYNC 0x0008 /* synchronous message operation */
97 #define MSGF_INTRANSIT 0x0010 /* in-transit (IPI) */
98 #define MSGF_ABORTABLE 0x0080 /* message supports abort */
100 #define MSG_CMD_CDEV 0x00010000
101 #define MSG_CMD_VFS 0x00020000
102 #define MSG_CMD_SYSCALL 0x00030000
103 #define MSG_SUBCMD_MASK 0x0000FFFF
106 MALLOC_DECLARE(M_LWKTMSG);
110 * Notes on port processing requirements:
113 * - may return synchronous error code (error != EASYNC) directly and
114 * does not need to check or set MSGF_DONE if so, or set ms_target_port
115 * - for asynch procesing should clear MSGF_DONE and set ms_target_port
116 * to port prior to initiation of the command.
119 * - wait for a particular message to be returned.
122 * - wait for a new message on the specified port.
125 * - reply a message (executed on the originating port to return a
126 * message to it). This can be rather involved if abort is to be
127 * supported, see lwkt_default_replyport(). Generally speaking
128 * one sets MSGF_DONE. If MSGF_SYNC is set the message is not
129 * queued to the port and the reply code wakes up the waiter
132 * The use of mp_u.td and mp_u.spin is specific to the port callback function
133 * set. Default ports are tied to specific threads and use cpu locality
134 * of reference and mp_u.td (and not mp_u.spin at all). Descriptor ports
135 * assume access via descriptors, signal interruption, etc. Such ports use
136 * mp_u.spin (and not mp_u.td at all) and may be accessed by multiple threads.
138 typedef struct lwkt_port {
139 lwkt_msg_queue mp_msgq;
142 struct spinlock spin;
146 void * (*mp_getport)(lwkt_port_t);
147 int (*mp_putport)(lwkt_port_t, lwkt_msg_t);
148 int (*mp_waitmsg)(lwkt_msg_t, int flags);
149 void * (*mp_waitport)(lwkt_port_t, int flags);
150 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t);
155 #define mpu_td mp_u.td
156 #define mpu_spin mp_u.spin
157 #define mpu_data mp_u.data
161 #define MSGPORTF_WAITING 0x0001
164 * These functions are good for userland as well as the kernel. The
165 * messaging function support for userland is provided by the kernel's
166 * kern/lwkt_msgport.c. The port functions are provided by userland.
169 void lwkt_initport_thread(lwkt_port_t, struct thread *);
170 void lwkt_initport_spin(lwkt_port_t);
171 void lwkt_initport_panic(lwkt_port_t);
172 void lwkt_initport_replyonly_null(lwkt_port_t);
173 void lwkt_initport_replyonly(lwkt_port_t,
174 void (*rportfn)(lwkt_port_t, lwkt_msg_t));
175 void lwkt_initport_putonly(lwkt_port_t,
176 int (*pportfn)(lwkt_port_t, lwkt_msg_t));
178 void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t);
179 int lwkt_domsg(lwkt_port_t, lwkt_msg_t, int);
180 int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t);
181 void lwkt_abortmsg(lwkt_msg_t);