xref: /freebsd/sys/cam/cam_sim.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
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 struct cam_devq *
50 cam_simq_alloc(u_int32_t max_sim_transactions)
51 {
52 	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
53 }
54 
55 void
56 cam_simq_free(struct cam_devq *devq)
57 {
58 	cam_devq_free(devq);
59 }
60 
61 struct cam_sim *
62 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
63 	      const char *sim_name, void *softc, u_int32_t unit,
64 	      struct mtx *mtx, int max_dev_transactions,
65 	      int max_tagged_dev_transactions, struct cam_devq *queue)
66 {
67 	struct cam_sim *sim;
68 
69 	if (mtx == NULL)
70 		return (NULL);
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->max_ccbs = 8;	/* Reserve for management purposes. */
91 	sim->mtx = mtx;
92 	if (mtx == &Giant) {
93 		sim->flags |= 0;
94 		callout_init(&sim->callout, 0);
95 	} else {
96 		sim->flags |= CAM_SIM_MPSAFE;
97 		callout_init(&sim->callout, 1);
98 	}
99 
100 	SLIST_INIT(&sim->ccb_freeq);
101 	TAILQ_INIT(&sim->sim_doneq);
102 
103 	return (sim);
104 }
105 
106 void
107 cam_sim_free(struct cam_sim *sim, int free_devq)
108 {
109 	union ccb *ccb;
110 	int error;
111 
112 	mtx_assert(sim->mtx, MA_OWNED);
113 	sim->refcount--;
114 	if (sim->refcount > 0) {
115 		error = msleep(sim, sim->mtx, PRIBIO, "simfree", 0);
116 		KASSERT(error == 0, ("invalid error value for msleep(9)"));
117 	}
118 
119 	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
120 
121 	while ((ccb = (union ccb *)SLIST_FIRST(&sim->ccb_freeq)) != NULL) {
122 		SLIST_REMOVE_HEAD(&sim->ccb_freeq, xpt_links.sle);
123 		xpt_free_ccb(ccb);
124 	}
125 	if (free_devq)
126 		cam_simq_free(sim->devq);
127 	free(sim, M_CAMSIM);
128 }
129 
130 void
131 cam_sim_release(struct cam_sim *sim)
132 {
133 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
134 	mtx_assert(sim->mtx, MA_OWNED);
135 
136 	sim->refcount--;
137 	if (sim->refcount == 0)
138 		wakeup(sim);
139 }
140 
141 void
142 cam_sim_hold(struct cam_sim *sim)
143 {
144 	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
145 	mtx_assert(sim->mtx, MA_OWNED);
146 
147 	sim->refcount++;
148 }
149 
150 void
151 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
152 {
153 	sim->path_id = path_id;
154 }
155