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/bus.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/mutex.h> 40 41 #include <cam/cam.h> 42 #include <cam/cam_ccb.h> 43 #include <cam/cam_queue.h> 44 #include <cam/cam_sim.h> 45 #include <cam/cam_xpt.h> 46 47 #define CAM_PATH_ANY (u_int32_t)-1 48 49 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 50 51 static struct mtx cam_sim_free_mtx; 52 MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF); 53 54 struct cam_devq * 55 cam_simq_alloc(u_int32_t max_sim_transactions) 56 { 57 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 58 } 59 60 void 61 cam_simq_free(struct cam_devq *devq) 62 { 63 cam_devq_free(devq); 64 } 65 66 67 68 /** 69 * @brief allocate a new sim and fill in the details 70 * 71 * A Storage Interface Module (SIM) is the interface between CAM and 72 * hardware. SIM receives CCBs from CAM via @p sim_action callback and 73 * translates them into DMA or other hardware transactions. During system 74 * dumps, it can be polled with the @p sim_poll callback. CCB processing is 75 * terminated by calling @c xpt_done(). 76 * 77 * The @p mtx acts as a perimeter lock for the SIM. All calls into the SIM's 78 * @p sim_action are made with this lock held. It is also used to hold/release 79 * a SIM, managing its reference count. When the lock is NULL, the SIM is 100% 80 * responsible for locking (and the reference counting is done with a shared 81 * lock. 82 * 83 * The cam_devq passed in (@c queue) is used to arbitrate the number of 84 * outstanding transactions to the SIM. For HBAs that have global limits shared 85 * between the different buses, the same devq should be specified for each bus 86 * attached to the SIM. 87 * 88 * @param sim_action Function to call to process CCBs 89 * @param sim_poll Function to poll the hardware for completions 90 * @param sim_name Name of SIM class 91 * @param softc Software context associated with the SIM 92 * @param unit Unit number of SIM 93 * @param mtx Mutex to lock while interacting with the SIM, or NULL 94 * for a SIM that handle its own locking to enable multi 95 * queue support. 96 * @param max_dev_transactions Maximum number of concurrent untagged 97 * transactions possible 98 * @param max_tagged_dev_transactions Maximum number of concurrent tagged 99 * transactions possible. 100 * @param queue The cam_devq to use for this SIM. 101 */ 102 struct cam_sim * 103 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 104 const char *sim_name, void *softc, u_int32_t unit, 105 struct mtx *mtx, int max_dev_transactions, 106 int max_tagged_dev_transactions, struct cam_devq *queue) 107 { 108 struct cam_sim *sim; 109 110 sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT); 111 if (sim == NULL) 112 return (NULL); 113 114 sim->sim_action = sim_action; 115 sim->sim_poll = sim_poll; 116 sim->sim_name = sim_name; 117 sim->softc = softc; 118 sim->path_id = CAM_PATH_ANY; 119 sim->unit_number = unit; 120 sim->bus_id = 0; /* set in xpt_bus_register */ 121 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 122 sim->max_dev_openings = max_dev_transactions; 123 sim->flags = 0; 124 sim->refcount = 1; 125 sim->devq = queue; 126 sim->mtx = mtx; 127 return (sim); 128 } 129 130 void 131 cam_sim_free(struct cam_sim *sim, int free_devq) 132 { 133 struct mtx *mtx; 134 int error; 135 136 if (sim->mtx == NULL) { 137 mtx = &cam_sim_free_mtx; 138 mtx_lock(mtx); 139 } else { 140 mtx = sim->mtx; 141 mtx_assert(mtx, MA_OWNED); 142 } 143 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 144 sim->refcount--; 145 if (sim->refcount > 0) { 146 error = msleep(sim, mtx, PRIBIO, "simfree", 0); 147 KASSERT(error == 0, ("invalid error value for msleep(9)")); 148 } 149 KASSERT(sim->refcount == 0, ("sim->refcount == 0")); 150 if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */ 151 mtx_unlock(mtx); 152 153 if (free_devq) 154 cam_simq_free(sim->devq); 155 free(sim, M_CAMSIM); 156 } 157 158 void 159 cam_sim_release(struct cam_sim *sim) 160 { 161 struct mtx *mtx; 162 163 if (sim->mtx == NULL) 164 mtx = &cam_sim_free_mtx; 165 else if (!mtx_owned(sim->mtx)) 166 mtx = sim->mtx; 167 else 168 mtx = NULL; /* We hold the lock. */ 169 if (mtx) 170 mtx_lock(mtx); 171 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 172 sim->refcount--; 173 if (sim->refcount == 0) 174 wakeup(sim); 175 if (mtx) 176 mtx_unlock(mtx); 177 } 178 179 void 180 cam_sim_hold(struct cam_sim *sim) 181 { 182 struct mtx *mtx; 183 184 if (sim->mtx == NULL) 185 mtx = &cam_sim_free_mtx; 186 else if (!mtx_owned(sim->mtx)) 187 mtx = sim->mtx; 188 else 189 mtx = NULL; /* We hold the lock. */ 190 if (mtx) 191 mtx_lock(mtx); 192 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 193 sim->refcount++; 194 if (mtx) 195 mtx_unlock(mtx); 196 } 197 198 void 199 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 200 { 201 sim->path_id = path_id; 202 } 203