2 * Common functions for SCSI Interface Modules (SIMs).
4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
6 * Copyright (c) 1997 Justin T. Gibbs.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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.
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
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
39 #include <sys/mutex.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>
48 #define CAM_PATH_ANY (u_int32_t)-1
50 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
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);
56 cam_simq_alloc(u_int32_t max_sim_transactions)
58 return (cam_devq_alloc(/*size*/0, max_sim_transactions));
62 cam_simq_free(struct cam_devq *devq)
70 * @brief allocate a new sim and fill in the details
72 * A Storage Interface Module (SIM) is the interface between CAM and
73 * hardware. SIM receives CCBs from CAM via @p sim_action callback and
74 * translates them into DMA or other hardware transactions. During system
75 * dumps, it can be polled with the @p sim_poll callback. CCB processing is
76 * terminated by calling @c xpt_done().
78 * The @p mtx acts as a perimeter lock for the SIM. All calls into the SIM's
79 * @p sim_action are made with this lock held. It is also used to hold/release
80 * a SIM, managing its reference count. When the lock is NULL, the SIM is 100%
81 * responsible for locking (and the reference counting is done with a shared
84 * The cam_devq passed in (@c queue) is used to arbitrate the number of
85 * outstanding transactions to the SIM. For HBAs that have global limits shared
86 * between the different buses, the same devq should be specified for each bus
87 * attached to the SIM.
89 * @param sim_action Function to call to process CCBs
90 * @param sim_poll Function to poll the hardware for completions
91 * @param sim_name Name of SIM class
92 * @param softc Software context associated with the SIM
93 * @param unit Unit number of SIM
94 * @param mtx Mutex to lock while interacting with the SIM, or NULL
95 * for a SIM that handle its own locking to enable multi
97 * @param max_dev_transactions Maximum number of concurrent untagged
98 * transactions possible
99 * @param max_tagged_dev_transactions Maximum number of concurrent tagged
100 * transactions possible.
101 * @param queue The cam_devq to use for this SIM.
104 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
105 const char *sim_name, void *softc, u_int32_t unit,
106 struct mtx *mtx, int max_dev_transactions,
107 int max_tagged_dev_transactions, struct cam_devq *queue)
111 sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT);
115 sim->sim_action = sim_action;
116 sim->sim_poll = sim_poll;
117 sim->sim_name = sim_name;
119 sim->path_id = CAM_PATH_ANY;
120 sim->sim_dev = NULL; /* set only by cam_sim_alloc_dev */
121 sim->unit_number = unit;
122 sim->bus_id = 0; /* set in xpt_bus_register */
123 sim->max_tagged_dev_openings = max_tagged_dev_transactions;
124 sim->max_dev_openings = max_dev_transactions;
129 callout_init(&sim->callout, 1);
134 * @brief allocate a new sim and fill in the details with a device_t
136 * Just like @c cam_sim_alloc, but with an additional paramter.
138 * @param dev A newbus device that's associated with the
139 * sim. Must be non-NULL.
142 cam_sim_alloc_dev(sim_action_func sim_action, sim_poll_func sim_poll,
143 const char *sim_name, void *softc, device_t dev, struct mtx *mtx,
144 int max_dev_transactions, int max_tagged_dev_transactions,
145 struct cam_devq *queue)
149 KASSERT(dev != NULL, ("%s: dev is null for sim_name %s softc %p\n",
150 __func__, sim_name, softc));
152 sim = cam_sim_alloc(sim_action, sim_poll, sim_name, softc,
153 device_get_unit(dev), mtx, max_dev_transactions,
154 max_tagged_dev_transactions, queue);
161 cam_sim_free(struct cam_sim *sim, int free_devq)
166 if (sim->mtx == NULL) {
167 mtx = &cam_sim_free_mtx;
171 mtx_assert(mtx, MA_OWNED);
173 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
175 if (sim->refcount > 0) {
176 error = msleep(sim, mtx, PRIBIO, "simfree", 0);
177 KASSERT(error == 0, ("invalid error value for msleep(9)"));
179 KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
180 if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */
184 cam_simq_free(sim->devq);
189 cam_sim_release(struct cam_sim *sim)
193 if (sim->mtx == NULL)
194 mtx = &cam_sim_free_mtx;
195 else if (!mtx_owned(sim->mtx))
198 mtx = NULL; /* We hold the lock. */
201 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
203 if (sim->refcount == 0)
210 cam_sim_hold(struct cam_sim *sim)
214 if (sim->mtx == NULL)
215 mtx = &cam_sim_free_mtx;
216 else if (!mtx_owned(sim->mtx))
219 mtx = NULL; /* We hold the lock. */
222 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
229 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
231 sim->path_id = path_id;