1 /*- 2 * Common functions for SCSI Interface Modules (SIMs). 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #include <sys/mutex.h> 38 39 #include <cam/cam.h> 40 #include <cam/cam_ccb.h> 41 #include <cam/cam_queue.h> 42 #include <cam/cam_sim.h> 43 #include <cam/cam_xpt.h> 44 45 #define CAM_PATH_ANY (uint32_t)-1 46 47 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 48 49 static struct mtx cam_sim_free_mtx; 50 MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF); 51 52 struct cam_devq * 53 cam_simq_alloc(uint32_t max_sim_transactions) 54 { 55 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 56 } 57 58 void 59 cam_simq_free(struct cam_devq *devq) 60 { 61 cam_devq_free(devq); 62 } 63 64 65 66 /** 67 * @brief allocate a new sim and fill in the details 68 * 69 * A Storage Interface Module (SIM) is the interface between CAM and 70 * hardware. SIM receives CCBs from CAM via @p sim_action callback and 71 * translates them into DMA or other hardware transactions. During system 72 * dumps, it can be polled with the @p sim_poll callback. CCB processing is 73 * terminated by calling @c xpt_done(). 74 * 75 * The @p mtx acts as a perimeter lock for the SIM. All calls into the SIM's 76 * @p sim_action are made with this lock held. It is also used to hold/release 77 * a SIM, managing its reference count. When the lock is NULL, the SIM is 100% 78 * responsible for locking (and the reference counting is done with a shared 79 * lock. 80 * 81 * The cam_devq passed in (@c queue) is used to arbitrate the number of 82 * outstanding transactions to the SIM. For HBAs that have global limits shared 83 * between the different buses, the same devq should be specified for each bus 84 * attached to the SIM. 85 * 86 * @param sim_action Function to call to process CCBs 87 * @param sim_poll Function to poll the hardware for completions 88 * @param sim_name Name of SIM class 89 * @param softc Software context associated with the SIM 90 * @param unit Unit number of SIM 91 * @param mtx Mutex to lock while interacting with the SIM, or NULL 92 * for a SIM that handle its own locking to enable multi 93 * queue support. 94 * @param max_dev_transactions Maximum number of concurrent untagged 95 * transactions possible 96 * @param max_tagged_dev_transactions Maximum number of concurrent tagged 97 * transactions possible. 98 * @param queue The cam_devq to use for this SIM. 99 */ 100 struct cam_sim * 101 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 102 const char *sim_name, void *softc, uint32_t unit, 103 struct mtx *mtx, int max_dev_transactions, 104 int max_tagged_dev_transactions, struct cam_devq *queue) 105 { 106 struct cam_sim *sim; 107 108 sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT); 109 if (sim == NULL) 110 return (NULL); 111 112 sim->sim_action = sim_action; 113 sim->sim_poll = sim_poll; 114 sim->sim_name = sim_name; 115 sim->softc = softc; 116 sim->path_id = CAM_PATH_ANY; 117 sim->unit_number = unit; 118 sim->bus_id = 0; /* set in xpt_bus_register */ 119 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 120 sim->max_dev_openings = max_dev_transactions; 121 sim->flags = 0; 122 sim->refcount = 1; 123 sim->devq = queue; 124 sim->mtx = mtx; 125 return (sim); 126 } 127 128 /** 129 * @brief frees up the sim 130 * 131 * Frees up the CAM @c sim and optionally the devq. If a mutex is associated 132 * with the sim, it must be locked on entry. It will remain locked on 133 * return. 134 * 135 * This function will wait for all outstanding reference to the sim to clear 136 * before returning. 137 * 138 * @param sim The sim to free 139 * @param free_devq Free the devq associated with the sim at creation. 140 */ 141 void 142 cam_sim_free(struct cam_sim *sim, int free_devq) 143 { 144 struct mtx *mtx; 145 int error __diagused; 146 147 if (sim->mtx == NULL) { 148 mtx = &cam_sim_free_mtx; 149 mtx_lock(mtx); 150 } else { 151 mtx = sim->mtx; 152 mtx_assert(mtx, MA_OWNED); 153 } 154 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 155 sim->refcount--; 156 if (sim->refcount > 0) { 157 error = msleep(sim, mtx, PRIBIO, "simfree", 0); 158 KASSERT(error == 0, ("invalid error value for msleep(9)")); 159 } 160 KASSERT(sim->refcount == 0, ("sim->refcount == 0")); 161 if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */ 162 mtx_unlock(mtx); 163 164 if (free_devq) 165 cam_simq_free(sim->devq); 166 free(sim, M_CAMSIM); 167 } 168 169 void 170 cam_sim_release(struct cam_sim *sim) 171 { 172 struct mtx *mtx; 173 174 if (sim->mtx == NULL) 175 mtx = &cam_sim_free_mtx; 176 else if (!mtx_owned(sim->mtx)) 177 mtx = sim->mtx; 178 else 179 mtx = NULL; /* We hold the lock. */ 180 if (mtx) 181 mtx_lock(mtx); 182 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 183 sim->refcount--; 184 if (sim->refcount == 0) 185 wakeup(sim); 186 if (mtx) 187 mtx_unlock(mtx); 188 } 189 190 void 191 cam_sim_hold(struct cam_sim *sim) 192 { 193 struct mtx *mtx; 194 195 if (sim->mtx == NULL) 196 mtx = &cam_sim_free_mtx; 197 else if (!mtx_owned(sim->mtx)) 198 mtx = sim->mtx; 199 else 200 mtx = NULL; /* We hold the lock. */ 201 if (mtx) 202 mtx_lock(mtx); 203 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 204 sim->refcount++; 205 if (mtx) 206 mtx_unlock(mtx); 207 } 208 209 void 210 cam_sim_set_path(struct cam_sim *sim, uint32_t path_id) 211 { 212 sim->path_id = path_id; 213 } 214