cam_sim.c revision 248800 
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: head/sys/cam/cam_sim.c 248800 2013-03-27 18:55:01Z mav $");
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
47static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
48
49struct cam_devq *
50cam_simq_alloc(u_int32_t max_sim_transactions)
51{
52	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
53}
54
55void
56cam_simq_free(struct cam_devq *devq)
57{
58	cam_devq_free(devq);
59}
60
61struct cam_sim *
62cam_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
106void
107cam_sim_free(struct cam_sim *sim, int free_devq)
108{
109	union ccb *ccb;
110	int error;
111
112	sim->refcount--;
113	if (sim->refcount > 0) {
114		error = msleep(sim, sim->mtx, PRIBIO, "simfree", 0);
115		KASSERT(error == 0, ("invalid error value for msleep(9)"));
116	}
117
118	KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
119
120	while ((ccb = (union ccb *)SLIST_FIRST(&sim->ccb_freeq)) != NULL) {
121		SLIST_REMOVE_HEAD(&sim->ccb_freeq, xpt_links.sle);
122		xpt_free_ccb(ccb);
123	}
124	if (free_devq)
125		cam_simq_free(sim->devq);
126	free(sim, M_CAMSIM);
127}
128
129void
130cam_sim_release(struct cam_sim *sim)
131{
132	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
133	mtx_assert(sim->mtx, MA_OWNED);
134
135	sim->refcount--;
136	if (sim->refcount == 0)
137		wakeup(sim);
138}
139
140void
141cam_sim_hold(struct cam_sim *sim)
142{
143	KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
144	mtx_assert(sim->mtx, MA_OWNED);
145
146	sim->refcount++;
147}
148
149void
150cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
151{
152	sim->path_id = path_id;
153}
154