xref: /illumos-gate/usr/src/uts/sun4v/io/drctl_impl.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/door.h>
29 #include <sys/note.h>
30 #include <sys/drctl.h>
31 #include <sys/drctl_impl.h>
32 #include <sys/ddi.h>
33 #include <sys/sunddi.h>
34 #include <sys/dr_util.h>
35 
36 static door_handle_t drctl_dh;	/* Door for upcalls */
37 
38 
39 int
40 i_drctl_ioctl(int cmd, intptr_t arg)
41 {
42 	int rv;
43 	drctl_setup_t setup_rqst;
44 
45 	switch (cmd) {
46 	case DRCTL_IOCTL_CONNECT_SERVER:
47 		if (ddi_copyin((caddr_t)arg,
48 		    &setup_rqst, sizeof (setup_rqst), 0) != 0) {
49 			cmn_err(CE_WARN, "i_drctl_ioctl: ddi_copyin failed "
50 			    "for DRCTL_IOCTL_CONNECT_SERVER");
51 			rv = EFAULT;
52 			break;
53 		}
54 
55 		drctl_dh = door_ki_lookup(setup_rqst.did);
56 		rv = 0;
57 		break;
58 
59 	default:
60 		rv = EIO;
61 	}
62 
63 	return (rv);
64 }
65 
66 int
67 i_drctl_send(void *msg, size_t size, void **obufp, size_t *osize)
68 {
69 	int up_err;
70 	int rv = 0;
71 	door_arg_t door_args;
72 	door_handle_t dh = drctl_dh;
73 	static const char me[] = "i_drctl_send";
74 
75 retry:
76 	if (dh)
77 		door_ki_hold(dh);
78 	else
79 		return (EIO);
80 
81 	door_args.data_ptr = (char *)msg;
82 	door_args.data_size = size;
83 	door_args.desc_ptr = NULL;
84 	door_args.desc_num = 0;
85 
86 	/*
87 	 * We don't know the size of the message the daemon
88 	 * will pass back to us.  By setting rbuf to NULL,
89 	 * we force the door code to allocate a buf of the
90 	 * appropriate size.  We must set rsize > 0, however,
91 	 * else the door code acts as if no response was
92 	 * expected and doesn't pass the data to us.
93 	 */
94 	door_args.rbuf = NULL;
95 	door_args.rsize = 1;
96 	DR_DBG_CTL("%s: msg %p size %ld obufp %p osize %p\n",
97 	    me, msg, size, (void *)obufp, (void *)osize);
98 
99 	up_err = door_ki_upcall_limited(dh, &door_args, NULL, SIZE_MAX, 0);
100 	if (up_err == 0) {
101 		if (door_args.rbuf == NULL)
102 			goto done;
103 
104 		DR_DBG_CTL("%s: rbuf %p rsize %ld\n", me,
105 		    (void *)door_args.rbuf, door_args.rsize);
106 
107 		if (obufp != NULL) {
108 			*obufp = door_args.rbuf;
109 			*osize = door_args.rsize;
110 			DR_DBG_KMEM("%s: (door) alloc addr %p size %ld\n",
111 			    __func__,
112 			    (void *)(door_args.rbuf), door_args.rsize);
113 		} else {
114 			/*
115 			 * No output buffer pointer was passed in,
116 			 * so the response buffer allocated by the
117 			 * door code must be deallocated.
118 			 */
119 			DR_DBG_KMEM("%s: free addr %p size %ld\n", __func__,
120 			    (void *)(door_args.rbuf), door_args.rsize);
121 			kmem_free(door_args.rbuf, door_args.rsize);
122 		}
123 	} else {
124 		switch (up_err) {
125 		case EINTR:
126 			DR_DBG_CTL("%s: door call returned EINTR\n", me);
127 			_NOTE(FALLTHROUGH)
128 		case EAGAIN:
129 			/*
130 			 * Server process may be forking, try again.
131 			 */
132 			door_ki_rele(dh);
133 			delay(hz);
134 			goto retry;
135 		case EBADF:
136 		case EINVAL:
137 			drctl_dh = NULL;
138 			DR_DBG_CTL(
139 			    "%s: door call failed with %d\n", me, up_err);
140 			rv = EIO;
141 			break;
142 		default:
143 			DR_DBG_CTL("%s: unexpected return "
144 			    "code %d from door_ki_upcall\n", me, up_err);
145 			rv = EIO;
146 			break;
147 		}
148 	}
149 
150 done:
151 	door_ki_rele(dh);
152 	return (rv);
153 }
154