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
50static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
51
52static struct mtx cam_sim_free_mtx;
53MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF);
54
55struct cam_devq *
56cam_simq_alloc(u_int32_t max_sim_transactions)
57{
58	return (cam_devq_alloc(/*size*/0, max_sim_transactions));
59}
60
61void
62cam_simq_free(struct cam_devq *devq)
63{
64	cam_devq_free(devq);
65}
66
67struct cam_sim *
68cam_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
97struct cam_sim *
98cam_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
116void
117cam_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
144void
145cam_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
165void
166cam_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
184void
185cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
186{
187	sim->path_id = path_id;
188}
189