xref: /freebsd/sys/cam/cam_sim.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
1 /*-
2  * Common functions for SCSI Interface Modules (SIMs).
3  *
4  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
5  *
6  * Copyright (c) 1997 Justin T. Gibbs.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification, immediately at the beginning of the file.
15  * 2. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 
41 #include <cam/cam.h>
42 #include <cam/cam_ccb.h>
43 #include <cam/cam_sim.h>
44 #include <cam/cam_queue.h>
45 #include <cam/cam_xpt.h>
46 
47 #define CAM_PATH_ANY (u_int32_t)-1
48 
49 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
50 
51 static struct mtx cam_sim_free_mtx;
52 MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF);
53 
54 struct cam_devq *
55 cam_simq_alloc(u_int32_t max_sim_transactions)
56 {
57 	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
58 }
59 
60 void
61 cam_simq_free(struct cam_devq *devq)
62 {
63 	cam_devq_free(devq);
64 }
65 
66 struct cam_sim *
67 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
68 	      const char *sim_name, void *softc, u_int32_t unit,
69 	      struct mtx *mtx, int max_dev_transactions,
70 	      int max_tagged_dev_transactions, struct cam_devq *queue)
71 {
72 	struct cam_sim *sim;
73 
74 	sim = (struct cam_sim *)malloc(sizeof(struct cam_sim),
75 	    M_CAMSIM, M_ZERO | M_NOWAIT);
76 
77 	if (sim == NULL)
78 		return (NULL);
79 
80 	sim->sim_action = sim_action;
81 	sim->sim_poll = sim_poll;
82 	sim->sim_name = sim_name;
83 	sim->softc = softc;
84 	sim->path_id = CAM_PATH_ANY;
85 	sim->unit_number = unit;
86 	sim->bus_id = 0;	/* set in xpt_bus_register */
87 	sim->max_tagged_dev_openings = max_tagged_dev_transactions;
88 	sim->max_dev_openings = max_dev_transactions;
89 	sim->flags = 0;
90 	sim->refcount = 1;
91 	sim->devq = queue;
92 	sim->mtx = mtx;
93 	if (mtx == &Giant) {
94 		sim->flags |= 0;
95 		callout_init(&sim->callout, 0);
96 	} else {
97 		sim->flags |= CAM_SIM_MPSAFE;
98 		callout_init(&sim->callout, 1);
99 	}
100 	return (sim);
101 }
102 
103 void
104 cam_sim_free(struct cam_sim *sim, int free_devq)
105 {
106 	struct mtx *mtx = sim->mtx;
107 	int error;
108 
109 	if (mtx) {
110 		mtx_assert(mtx, MA_OWNED);
111 	} else {
112 		mtx = &cam_sim_free_mtx;
113 		mtx_lock(mtx);
114 	}
115 	sim->refcount--;
116 	if (sim->refcount > 0) {
117 		error = msleep(sim, mtx, PRIBIO, "simfree", 0);
118 		KASSERT(error == 0, ("invalid error value for msleep(9)"));
119 	}
120 	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
121 	if (sim->mtx == NULL)
122 		mtx_unlock(mtx);
123 
124 	if (free_devq)
125 		cam_simq_free(sim->devq);
126 	free(sim, M_CAMSIM);
127 }
128 
129 void
130 cam_sim_release(struct cam_sim *sim)
131 {
132 	struct mtx *mtx = sim->mtx;
133 
134 	if (mtx) {
135 		if (!mtx_owned(mtx))
136 			mtx_lock(mtx);
137 		else
138 			mtx = NULL;
139 	} else {
140 		mtx = &cam_sim_free_mtx;
141 		mtx_lock(mtx);
142 	}
143 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
144 	sim->refcount--;
145 	if (sim->refcount == 0)
146 		wakeup(sim);
147 	if (mtx)
148 		mtx_unlock(mtx);
149 }
150 
151 void
152 cam_sim_hold(struct cam_sim *sim)
153 {
154 	struct mtx *mtx = sim->mtx;
155 
156 	if (mtx) {
157 		if (!mtx_owned(mtx))
158 			mtx_lock(mtx);
159 		else
160 			mtx = NULL;
161 	} else {
162 		mtx = &cam_sim_free_mtx;
163 		mtx_lock(mtx);
164 	}
165 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
166 	sim->refcount++;
167 	if (mtx)
168 		mtx_unlock(mtx);
169 }
170 
171 void
172 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
173 {
174 	sim->path_id = path_id;
175 }
176