1 /* 2 * Common functions for SCSI Interface Modules (SIMs). 3 * 4 * Copyright (c) 1997 Justin T. Gibbs. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions, and the following disclaimer, 12 * without modification, immediately at the beginning of the file. 13 * 2. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/sys/cam/cam_sim.c,v 1.3 1999/08/28 00:40:42 peter Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/malloc.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/spinlock.h> 37 38 #include <sys/thread2.h> 39 #include <sys/spinlock2.h> 40 #include <sys/mplock2.h> 41 42 #include "cam.h" 43 #include "cam_ccb.h" 44 #include "cam_sim.h" 45 #include "cam_queue.h" 46 #include "cam_xpt_sim.h" 47 48 #define CAM_PATH_ANY (u_int32_t)-1 49 50 MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 51 52 /* Drivers will use sim_mplock if they need the BGL */ 53 sim_lock sim_mplock; 54 55 void 56 cam_sim_lock(sim_lock *lock) 57 { 58 if (lock == &sim_mplock) 59 get_mplock(); 60 else 61 lockmgr(lock, LK_EXCLUSIVE); 62 } 63 64 void 65 cam_sim_unlock(sim_lock *lock) 66 { 67 if (lock == &sim_mplock) 68 rel_mplock(); 69 else 70 lockmgr(lock, LK_RELEASE); 71 } 72 73 int 74 cam_sim_cond_lock(sim_lock *lock) 75 { 76 if (lock == &sim_mplock) { 77 get_mplock(); 78 return(1); 79 } else if (lockstatus(lock, curthread) != LK_EXCLUSIVE) { 80 lockmgr(lock, LK_EXCLUSIVE); 81 return(1); 82 } 83 return(0); 84 } 85 86 void 87 cam_sim_cond_unlock(sim_lock *lock, int doun) 88 { 89 if (doun) { 90 if (lock == &sim_mplock) 91 rel_mplock(); 92 else 93 lockmgr(lock, LK_RELEASE); 94 } 95 } 96 97 /* 98 * lock can be NULL if sim was &dead_sim 99 */ 100 void 101 sim_lock_assert_owned(sim_lock *lock) 102 { 103 if (lock) { 104 if (lock == &sim_mplock) 105 ASSERT_MP_LOCK_HELD(); 106 else 107 KKASSERT(lockstatus(lock, curthread) != 0); 108 } 109 } 110 111 void 112 sim_lock_assert_unowned(sim_lock *lock) 113 { 114 if (lock) { 115 if (lock != &sim_mplock) 116 KKASSERT(lockstatus(lock, curthread) == 0); 117 } 118 } 119 120 int 121 sim_lock_sleep(void *ident, int flags, const char *wmesg, int timo, 122 sim_lock *lock) 123 { 124 int retval; 125 126 if (lock != &sim_mplock) { 127 /* lock should be held already */ 128 KKASSERT(lockstatus(lock, curthread) != 0); 129 tsleep_interlock(ident, flags); 130 lockmgr(lock, LK_RELEASE); 131 retval = tsleep(ident, flags | PINTERLOCKED, wmesg, timo); 132 } else { 133 retval = tsleep(ident, flags, wmesg, timo); 134 } 135 136 if (lock != &sim_mplock) { 137 lockmgr(lock, LK_EXCLUSIVE); 138 } 139 140 return (retval); 141 } 142 143 struct cam_devq * 144 cam_simq_alloc(u_int32_t max_sim_transactions) 145 { 146 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 147 } 148 149 void 150 cam_simq_release(struct cam_devq *devq) 151 { 152 cam_devq_release(devq); 153 } 154 155 /* 156 * cam_sim_alloc() may potentially be called from an interrupt (?) but 157 * unexpected things happen to the system if malloc() returns NULL so we 158 * use M_INTWAIT anyway. 159 */ 160 struct cam_sim * 161 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 162 const char *sim_name, void *softc, u_int32_t unit, 163 sim_lock *lock, int max_dev_transactions, 164 int max_tagged_dev_transactions, struct cam_devq *queue) 165 { 166 struct cam_sim *sim; 167 168 /* 169 * XXX ahd was limited to 256 instead of 512 for unknown reasons, 170 * move that to a global limit here. We may be able to remove this 171 * code, needs testing. 172 */ 173 if (max_dev_transactions > 256) 174 max_dev_transactions = 256; 175 if (max_tagged_dev_transactions > 256) 176 max_tagged_dev_transactions = 256; 177 178 /* 179 * Allocate a simq or use the supplied (possibly shared) simq. 180 */ 181 if (queue == NULL) 182 queue = cam_simq_alloc(max_tagged_dev_transactions); 183 else 184 cam_devq_reference(queue); 185 186 if (lock == NULL) 187 return (NULL); 188 189 sim = kmalloc(sizeof(struct cam_sim), M_CAMSIM, M_INTWAIT | M_ZERO); 190 sim->sim_action = sim_action; 191 sim->sim_poll = sim_poll; 192 sim->sim_name = sim_name; 193 sim->softc = softc; 194 sim->path_id = CAM_PATH_ANY; 195 sim->unit_number = unit; 196 sim->bus_id = 0; /* set in xpt_bus_register */ 197 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 198 sim->max_dev_openings = max_dev_transactions; 199 sim->flags = 0; 200 sim->refcount = 1; 201 sim->devq = queue; 202 sim->lock = lock; 203 if (lock == &sim_mplock) { 204 sim->flags |= 0; 205 callout_init(&sim->callout); 206 } else { 207 sim->flags |= CAM_SIM_MPSAFE; 208 callout_init_mp(&sim->callout); 209 } 210 211 SLIST_INIT(&sim->ccb_freeq); 212 TAILQ_INIT(&sim->sim_doneq); 213 spin_init(&sim->sim_spin, "cam_sim_alloc"); 214 215 return (sim); 216 } 217 218 void 219 cam_sim_set_max_tags(struct cam_sim *sim, int max_tags) 220 { 221 if (max_tags > 256) 222 max_tags = 256; 223 sim->max_tagged_dev_openings = max_tags; 224 cam_devq_set_openings(sim->devq, max_tags); 225 } 226 227 static void deadsim_poll(struct cam_sim *sim); 228 static void deadsim_action(struct cam_sim *sim, union ccb *ccb); 229 230 void 231 cam_sim_free(struct cam_sim *sim) 232 { 233 sim->sim_action = deadsim_action; 234 sim->sim_poll = deadsim_poll; 235 cam_sim_release(sim, CAM_SIM_SOFTC); 236 } 237 238 /* 239 * Note: the devq is still used by individual peripherals even if the 240 * backend sim disappears, so do not destroy it until the sim itself 241 * is no longer needed. 242 */ 243 void 244 cam_sim_release(struct cam_sim *sim, int flags) 245 { 246 if (flags & CAM_SIM_SOFTC) 247 sim->softc = NULL; 248 if (sim->refcount == 1) { 249 if (sim->devq) { 250 cam_simq_release(sim->devq); 251 sim->devq = NULL; 252 } 253 sim->refcount = 0; 254 kfree(sim, M_CAMSIM); 255 } else { 256 --sim->refcount; 257 } 258 } 259 260 void 261 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 262 { 263 sim->path_id = path_id; 264 } 265 266 /* 267 * Dead sim poll and action functions. The backend to the sim has gone 268 * away, aka usb, scsi device, etc... deal with it. 269 */ 270 static void 271 deadsim_poll(struct cam_sim *sim) 272 { 273 /* empty */ 274 } 275 276 static void 277 deadsim_action(struct cam_sim *sim, union ccb *ccb) 278 { 279 ccb->ccb_h.status = CAM_TID_INVALID; 280 xpt_done(ccb); 281 } 282 283