xref: /freebsd/sys/cam/cam_sim.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Common functions for SCSI Interface Modules (SIMs).
3  *
4  * Copyright (c) 1997 Justin T. Gibbs.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification, immediately at the beginning of the file.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 
39 #include <cam/cam.h>
40 #include <cam/cam_ccb.h>
41 #include <cam/cam_sim.h>
42 #include <cam/cam_queue.h>
43 #include <cam/cam_xpt.h>
44 
45 #define CAM_PATH_ANY (u_int32_t)-1
46 
47 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
48 
49 static struct mtx cam_sim_free_mtx;
50 MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF);
51 
52 struct cam_devq *
53 cam_simq_alloc(u_int32_t max_sim_transactions)
54 {
55 	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
56 }
57 
58 void
59 cam_simq_free(struct cam_devq *devq)
60 {
61 	cam_devq_free(devq);
62 }
63 
64 struct cam_sim *
65 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
66 	      const char *sim_name, void *softc, u_int32_t unit,
67 	      struct mtx *mtx, int max_dev_transactions,
68 	      int max_tagged_dev_transactions, struct cam_devq *queue)
69 {
70 	struct cam_sim *sim;
71 
72 	sim = (struct cam_sim *)malloc(sizeof(struct cam_sim),
73 	    M_CAMSIM, M_ZERO | M_NOWAIT);
74 
75 	if (sim == NULL)
76 		return (NULL);
77 
78 	sim->sim_action = sim_action;
79 	sim->sim_poll = sim_poll;
80 	sim->sim_name = sim_name;
81 	sim->softc = softc;
82 	sim->path_id = CAM_PATH_ANY;
83 	sim->unit_number = unit;
84 	sim->bus_id = 0;	/* set in xpt_bus_register */
85 	sim->max_tagged_dev_openings = max_tagged_dev_transactions;
86 	sim->max_dev_openings = max_dev_transactions;
87 	sim->flags = 0;
88 	sim->refcount = 1;
89 	sim->devq = queue;
90 	sim->mtx = mtx;
91 	if (mtx == &Giant) {
92 		sim->flags |= 0;
93 		callout_init(&sim->callout, 0);
94 	} else {
95 		sim->flags |= CAM_SIM_MPSAFE;
96 		callout_init(&sim->callout, 1);
97 	}
98 	return (sim);
99 }
100 
101 void
102 cam_sim_free(struct cam_sim *sim, int free_devq)
103 {
104 	struct mtx *mtx = sim->mtx;
105 	int error;
106 
107 	if (mtx) {
108 		mtx_assert(mtx, MA_OWNED);
109 	} else {
110 		mtx = &cam_sim_free_mtx;
111 		mtx_lock(mtx);
112 	}
113 	sim->refcount--;
114 	if (sim->refcount > 0) {
115 		error = msleep(sim, mtx, PRIBIO, "simfree", 0);
116 		KASSERT(error == 0, ("invalid error value for msleep(9)"));
117 	}
118 	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
119 	if (sim->mtx == NULL)
120 		mtx_unlock(mtx);
121 
122 	if (free_devq)
123 		cam_simq_free(sim->devq);
124 	free(sim, M_CAMSIM);
125 }
126 
127 void
128 cam_sim_release(struct cam_sim *sim)
129 {
130 	struct mtx *mtx = sim->mtx;
131 
132 	if (mtx) {
133 		if (!mtx_owned(mtx))
134 			mtx_lock(mtx);
135 		else
136 			mtx = NULL;
137 	} else {
138 		mtx = &cam_sim_free_mtx;
139 		mtx_lock(mtx);
140 	}
141 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
142 	sim->refcount--;
143 	if (sim->refcount == 0)
144 		wakeup(sim);
145 	if (mtx)
146 		mtx_unlock(mtx);
147 }
148 
149 void
150 cam_sim_hold(struct cam_sim *sim)
151 {
152 	struct mtx *mtx = sim->mtx;
153 
154 	if (mtx) {
155 		if (!mtx_owned(mtx))
156 			mtx_lock(mtx);
157 		else
158 			mtx = NULL;
159 	} else {
160 		mtx = &cam_sim_free_mtx;
161 		mtx_lock(mtx);
162 	}
163 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
164 	sim->refcount++;
165 	if (mtx)
166 		mtx_unlock(mtx);
167 }
168 
169 void
170 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
171 {
172 	sim->path_id = path_id;
173 }
174