xref: /freebsd/sys/cam/cam_sim.c (revision 0bf48626aaa33768078f5872b922b1487b3a9296)
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 = (struct cam_sim *)malloc(sizeof(struct cam_sim),
76 	    M_CAMSIM, M_ZERO | M_NOWAIT);
77 
78 	if (sim == NULL)
79 		return (NULL);
80 
81 	sim->sim_action = sim_action;
82 	sim->sim_poll = sim_poll;
83 	sim->sim_name = sim_name;
84 	sim->softc = softc;
85 	sim->path_id = CAM_PATH_ANY;
86 	sim->sim_dev = NULL;	/* set only by cam_sim_alloc_dev */
87 	sim->unit_number = unit;
88 	sim->bus_id = 0;	/* set in xpt_bus_register */
89 	sim->max_tagged_dev_openings = max_tagged_dev_transactions;
90 	sim->max_dev_openings = max_dev_transactions;
91 	sim->flags = 0;
92 	sim->refcount = 1;
93 	sim->devq = queue;
94 	sim->mtx = mtx;
95 	if (mtx == &Giant) {
96 		sim->flags |= 0;
97 		callout_init(&sim->callout, 0);
98 	} else {
99 		sim->flags |= CAM_SIM_MPSAFE;
100 		callout_init(&sim->callout, 1);
101 	}
102 	return (sim);
103 }
104 
105 struct cam_sim *
106 cam_sim_alloc_dev(sim_action_func sim_action, sim_poll_func sim_poll,
107 	      const char *sim_name, void *softc, device_t dev,
108 	      struct mtx *mtx, int max_dev_transactions,
109 	      int max_tagged_dev_transactions, struct cam_devq *queue)
110 {
111 	struct cam_sim *sim;
112 
113 	KASSERT(dev != NULL, ("%s: dev is null for sim_name %s softc %p\n",
114 	    __func__, sim_name, softc));
115 
116 	sim = cam_sim_alloc(sim_action, sim_poll, sim_name, softc,
117 	    device_get_unit(dev), mtx, max_dev_transactions,
118 	    max_tagged_dev_transactions, queue);
119 	if (sim != NULL)
120 		sim->sim_dev = dev;
121 	return (sim);
122 }
123 
124 void
125 cam_sim_free(struct cam_sim *sim, int free_devq)
126 {
127 	struct mtx *mtx = sim->mtx;
128 	int error;
129 
130 	if (mtx) {
131 		mtx_assert(mtx, MA_OWNED);
132 	} else {
133 		mtx = &cam_sim_free_mtx;
134 		mtx_lock(mtx);
135 	}
136 	sim->refcount--;
137 	if (sim->refcount > 0) {
138 		error = msleep(sim, mtx, PRIBIO, "simfree", 0);
139 		KASSERT(error == 0, ("invalid error value for msleep(9)"));
140 	}
141 	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
142 	if (sim->mtx == NULL)
143 		mtx_unlock(mtx);
144 
145 	if (free_devq)
146 		cam_simq_free(sim->devq);
147 	free(sim, M_CAMSIM);
148 }
149 
150 void
151 cam_sim_release(struct cam_sim *sim)
152 {
153 	struct mtx *mtx = sim->mtx;
154 
155 	if (mtx) {
156 		if (!mtx_owned(mtx))
157 			mtx_lock(mtx);
158 		else
159 			mtx = NULL;
160 	} else {
161 		mtx = &cam_sim_free_mtx;
162 		mtx_lock(mtx);
163 	}
164 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
165 	sim->refcount--;
166 	if (sim->refcount == 0)
167 		wakeup(sim);
168 	if (mtx)
169 		mtx_unlock(mtx);
170 }
171 
172 void
173 cam_sim_hold(struct cam_sim *sim)
174 {
175 	struct mtx *mtx = sim->mtx;
176 
177 	if (mtx) {
178 		if (!mtx_owned(mtx))
179 			mtx_lock(mtx);
180 		else
181 			mtx = NULL;
182 	} else {
183 		mtx = &cam_sim_free_mtx;
184 		mtx_lock(mtx);
185 	}
186 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
187 	sim->refcount++;
188 	if (mtx)
189 		mtx_unlock(mtx);
190 }
191 
192 void
193 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
194 {
195 	sim->path_id = path_id;
196 }
197