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 50 static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 51 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); 54 55 struct cam_devq * 56 cam_simq_alloc(u_int32_t max_sim_transactions) 57 { 58 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 59 } 60 61 void 62 cam_simq_free(struct cam_devq *devq) 63 { 64 cam_devq_free(devq); 65 } 66 67 68 69 /** 70 * @brief allocate a new sim and fill in the details 71 * 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(). 77 * 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 82 * lock. 83 * 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. 88 * 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 96 * queue support. 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. 102 */ 103 struct cam_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) 108 { 109 struct cam_sim *sim; 110 111 sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT); 112 if (sim == NULL) 113 return (NULL); 114 115 sim->sim_action = sim_action; 116 sim->sim_poll = sim_poll; 117 sim->sim_name = sim_name; 118 sim->softc = softc; 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; 125 sim->flags = 0; 126 sim->refcount = 1; 127 sim->devq = queue; 128 sim->mtx = mtx; 129 callout_init(&sim->callout, 1); 130 return (sim); 131 } 132 133 /** 134 * @brief allocate a new sim and fill in the details with a device_t 135 * 136 * Just like @c cam_sim_alloc, but with an additional paramter. 137 * 138 * @param dev A newbus device that's associated with the 139 * sim. Must be non-NULL. 140 */ 141 struct cam_sim * 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) 146 { 147 struct cam_sim *sim; 148 149 KASSERT(dev != NULL, ("%s: dev is null for sim_name %s softc %p\n", 150 __func__, sim_name, softc)); 151 152 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); 155 if (sim != NULL) 156 sim->sim_dev = dev; 157 return (sim); 158 } 159 160 void 161 cam_sim_free(struct cam_sim *sim, int free_devq) 162 { 163 struct mtx *mtx; 164 int error; 165 166 if (sim->mtx == NULL) { 167 mtx = &cam_sim_free_mtx; 168 mtx_lock(mtx); 169 } else { 170 mtx = sim->mtx; 171 mtx_assert(mtx, MA_OWNED); 172 } 173 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 174 sim->refcount--; 175 if (sim->refcount > 0) { 176 error = msleep(sim, mtx, PRIBIO, "simfree", 0); 177 KASSERT(error == 0, ("invalid error value for msleep(9)")); 178 } 179 KASSERT(sim->refcount == 0, ("sim->refcount == 0")); 180 if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */ 181 mtx_unlock(mtx); 182 183 if (free_devq) 184 cam_simq_free(sim->devq); 185 free(sim, M_CAMSIM); 186 } 187 188 void 189 cam_sim_release(struct cam_sim *sim) 190 { 191 struct mtx *mtx; 192 193 if (sim->mtx == NULL) 194 mtx = &cam_sim_free_mtx; 195 else if (!mtx_owned(sim->mtx)) 196 mtx = sim->mtx; 197 else 198 mtx = NULL; /* We hold the lock. */ 199 if (mtx) 200 mtx_lock(mtx); 201 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 202 sim->refcount--; 203 if (sim->refcount == 0) 204 wakeup(sim); 205 if (mtx) 206 mtx_unlock(mtx); 207 } 208 209 void 210 cam_sim_hold(struct cam_sim *sim) 211 { 212 struct mtx *mtx; 213 214 if (sim->mtx == NULL) 215 mtx = &cam_sim_free_mtx; 216 else if (!mtx_owned(sim->mtx)) 217 mtx = sim->mtx; 218 else 219 mtx = NULL; /* We hold the lock. */ 220 if (mtx) 221 mtx_lock(mtx); 222 KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); 223 sim->refcount++; 224 if (mtx) 225 mtx_unlock(mtx); 226 } 227 228 void 229 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 230 { 231 sim->path_id = path_id; 232 } 233