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 /** 131 * @brief frees up the sim 132 * 133 * Frees up the CAM @c sim and optionally the devq. If a mutex is associated 134 * with the sim, it must be locked on entry. It will remain locked on 135 * return. 136 * 137 * This function will wait for all outstanding reference to the sim to clear 138 * before returning. 139 * 140 * @param sim The sim to free 141 * @param free_devq Free the devq associated with the sim at creation. 142 */ 143 void 144 cam_sim_free(struct cam_sim *sim, int free_devq) 145 { 146 struct mtx *mtx; 147 int error __diagused; 148 149 if (sim->mtx == NULL) { 150 mtx = &cam_sim_free_mtx; 151 mtx_lock(mtx); 152 } else { 153 mtx = sim->mtx; 154 mtx_assert(mtx, MA_OWNED); 155 } 156 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 157 sim->refcount--; 158 if (sim->refcount > 0) { 159 error = msleep(sim, mtx, PRIBIO, "simfree", 0); 160 KASSERT(error == 0, ("invalid error value for msleep(9)")); 161 } 162 KASSERT(sim->refcount == 0, ("sim->refcount == 0")); 163 if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */ 164 mtx_unlock(mtx); 165 166 if (free_devq) 167 cam_simq_free(sim->devq); 168 free(sim, M_CAMSIM); 169 } 170 171 void 172 cam_sim_release(struct cam_sim *sim) 173 { 174 struct mtx *mtx; 175 176 if (sim->mtx == NULL) 177 mtx = &cam_sim_free_mtx; 178 else if (!mtx_owned(sim->mtx)) 179 mtx = sim->mtx; 180 else 181 mtx = NULL; /* We hold the lock. */ 182 if (mtx) 183 mtx_lock(mtx); 184 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 185 sim->refcount--; 186 if (sim->refcount == 0) 187 wakeup(sim); 188 if (mtx) 189 mtx_unlock(mtx); 190 } 191 192 void 193 cam_sim_hold(struct cam_sim *sim) 194 { 195 struct mtx *mtx; 196 197 if (sim->mtx == NULL) 198 mtx = &cam_sim_free_mtx; 199 else if (!mtx_owned(sim->mtx)) 200 mtx = sim->mtx; 201 else 202 mtx = NULL; /* We hold the lock. */ 203 if (mtx) 204 mtx_lock(mtx); 205 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 206 sim->refcount++; 207 if (mtx) 208 mtx_unlock(mtx); 209 } 210 211 void 212 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 213 { 214 sim->path_id = path_id; 215 } 216