xref: /freebsd/sys/cam/cam_sim.c (revision f61e92ca5a23450bc28169bbdd71d7674df98c19)
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 #include <sys/bus.h>
41 
42 #include <cam/cam.h>
43 #include <cam/cam_ccb.h>
44 #include <cam/cam_sim.h>
45 #include <cam/cam_queue.h>
46 #include <cam/cam_xpt.h>
47 
48 #define CAM_PATH_ANY (u_int32_t)-1
49 
50 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
51 
52 static struct mtx cam_sim_free_mtx;
53 MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF);
54 
55 struct cam_devq *
56 cam_simq_alloc(u_int32_t max_sim_transactions)
57 {
58 	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
59 }
60 
61 void
62 cam_simq_free(struct cam_devq *devq)
63 {
64 	cam_devq_free(devq);
65 }
66 
67 struct cam_sim *
68 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
69 	      const char *sim_name, void *softc, u_int32_t unit,
70 	      struct mtx *mtx, int max_dev_transactions,
71 	      int max_tagged_dev_transactions, struct cam_devq *queue)
72 {
73 	struct cam_sim *sim;
74 
75 	sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT);
76 	if (sim == NULL)
77 		return (NULL);
78 
79 	sim->sim_action = sim_action;
80 	sim->sim_poll = sim_poll;
81 	sim->sim_name = sim_name;
82 	sim->softc = softc;
83 	sim->path_id = CAM_PATH_ANY;
84 	sim->sim_dev = NULL;	/* set only by cam_sim_alloc_dev */
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 	callout_init(&sim->callout, 1);
94 	return (sim);
95 }
96 
97 struct cam_sim *
98 cam_sim_alloc_dev(sim_action_func sim_action, sim_poll_func sim_poll,
99 	      const char *sim_name, void *softc, device_t dev,
100 	      struct mtx *mtx, int max_dev_transactions,
101 	      int max_tagged_dev_transactions, struct cam_devq *queue)
102 {
103 	struct cam_sim *sim;
104 
105 	KASSERT(dev != NULL, ("%s: dev is null for sim_name %s softc %p\n",
106 	    __func__, sim_name, softc));
107 
108 	sim = cam_sim_alloc(sim_action, sim_poll, sim_name, softc,
109 	    device_get_unit(dev), mtx, max_dev_transactions,
110 	    max_tagged_dev_transactions, queue);
111 	if (sim != NULL)
112 		sim->sim_dev = dev;
113 	return (sim);
114 }
115 
116 void
117 cam_sim_free(struct cam_sim *sim, int free_devq)
118 {
119 	struct mtx *mtx;
120 	int error;
121 
122 	if (sim->mtx == NULL) {
123 		mtx = &cam_sim_free_mtx;
124 		mtx_lock(mtx);
125 	} else {
126 		mtx = sim->mtx;
127 		mtx_assert(mtx, MA_OWNED);
128 	}
129 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
130 	sim->refcount--;
131 	if (sim->refcount > 0) {
132 		error = msleep(sim, mtx, PRIBIO, "simfree", 0);
133 		KASSERT(error == 0, ("invalid error value for msleep(9)"));
134 	}
135 	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
136 	if (mtx == &cam_sim_free_mtx)	/* sim->mtx == NULL */
137 		mtx_unlock(mtx);
138 
139 	if (free_devq)
140 		cam_simq_free(sim->devq);
141 	free(sim, M_CAMSIM);
142 }
143 
144 void
145 cam_sim_release(struct cam_sim *sim)
146 {
147 	struct mtx *mtx;
148 
149 	if (sim->mtx == NULL)
150 		mtx = &cam_sim_free_mtx;
151 	else if (!mtx_owned(sim->mtx))
152 		mtx = sim->mtx;
153 	else
154 		mtx = NULL;	/* We hold the lock. */
155 	if (mtx)
156 		mtx_lock(mtx);
157 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
158 	sim->refcount--;
159 	if (sim->refcount == 0)
160 		wakeup(sim);
161 	if (mtx)
162 		mtx_unlock(mtx);
163 }
164 
165 void
166 cam_sim_hold(struct cam_sim *sim)
167 {
168 	struct mtx *mtx;
169 
170 	if (sim->mtx == NULL)
171 		mtx = &cam_sim_free_mtx;
172 	else if (!mtx_owned(sim->mtx))
173 		mtx = sim->mtx;
174 	else
175 		mtx = NULL;	/* We hold the lock. */
176 	if (mtx)
177 		mtx_lock(mtx);
178 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
179 	sim->refcount++;
180 	if (mtx)
181 		mtx_unlock(mtx);
182 }
183 
184 void
185 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
186 {
187 	sim->path_id = path_id;
188 }
189