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 * $DragonFly: src/sys/bus/cam/cam_sim.c,v 1.13 2008/07/18 00:07:21 dillon Exp $ 30 */ 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/malloc.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/spinlock.h> 38 39 #include <sys/thread2.h> 40 #include <sys/spinlock2.h> 41 #include <sys/mplock2.h> 42 43 #include "cam.h" 44 #include "cam_ccb.h" 45 #include "cam_sim.h" 46 #include "cam_queue.h" 47 #include "cam_xpt_sim.h" 48 49 #define CAM_PATH_ANY (u_int32_t)-1 50 51 MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 52 53 /* Drivers will use sim_mplock if they need the BGL */ 54 sim_lock sim_mplock; 55 56 void 57 cam_sim_lock(sim_lock *lock) 58 { 59 if (lock == &sim_mplock) 60 get_mplock(); 61 else 62 lockmgr(lock, LK_EXCLUSIVE); 63 } 64 65 void 66 cam_sim_unlock(sim_lock *lock) 67 { 68 if (lock == &sim_mplock) 69 rel_mplock(); 70 else 71 lockmgr(lock, LK_RELEASE); 72 } 73 74 int 75 cam_sim_cond_lock(sim_lock *lock) 76 { 77 if (lock == &sim_mplock) { 78 get_mplock(); 79 return(1); 80 } else if (lockstatus(lock, curthread) != LK_EXCLUSIVE) { 81 lockmgr(lock, LK_EXCLUSIVE); 82 return(1); 83 } 84 return(0); 85 } 86 87 void 88 cam_sim_cond_unlock(sim_lock *lock, int doun) 89 { 90 if (doun) { 91 if (lock == &sim_mplock) 92 rel_mplock(); 93 else 94 lockmgr(lock, LK_RELEASE); 95 } 96 } 97 98 /* 99 * lock can be NULL if sim was &dead_sim 100 */ 101 void 102 sim_lock_assert_owned(sim_lock *lock) 103 { 104 if (lock) { 105 if (lock == &sim_mplock) 106 ASSERT_MP_LOCK_HELD(curthread); 107 else 108 KKASSERT(lockstatus(lock, curthread) != 0); 109 } 110 } 111 112 void 113 sim_lock_assert_unowned(sim_lock *lock) 114 { 115 if (lock) { 116 if (lock != &sim_mplock) 117 KKASSERT(lockstatus(lock, curthread) == 0); 118 } 119 } 120 121 int 122 sim_lock_sleep(void *ident, int flags, const char *wmesg, int timo, 123 sim_lock *lock) 124 { 125 int retval; 126 127 if (lock != &sim_mplock) { 128 /* lock should be held already */ 129 KKASSERT(lockstatus(lock, curthread) != 0); 130 tsleep_interlock(ident, flags); 131 lockmgr(lock, LK_RELEASE); 132 retval = tsleep(ident, flags | PINTERLOCKED, wmesg, timo); 133 } else { 134 retval = tsleep(ident, flags, wmesg, timo); 135 } 136 137 if (lock != &sim_mplock) { 138 lockmgr(lock, LK_EXCLUSIVE); 139 } 140 141 return (retval); 142 } 143 144 struct cam_devq * 145 cam_simq_alloc(u_int32_t max_sim_transactions) 146 { 147 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 148 } 149 150 void 151 cam_simq_release(struct cam_devq *devq) 152 { 153 cam_devq_release(devq); 154 } 155 156 /* 157 * cam_sim_alloc() may potentially be called from an interrupt (?) but 158 * unexpected things happen to the system if malloc() returns NULL so we 159 * use M_INTWAIT anyway. 160 */ 161 struct cam_sim * 162 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 163 const char *sim_name, void *softc, u_int32_t unit, 164 sim_lock *lock, int max_dev_transactions, 165 int max_tagged_dev_transactions, struct cam_devq *queue) 166 { 167 struct cam_sim *sim; 168 169 /* 170 * XXX ahd was limited to 256 instead of 512 for unknown reasons, 171 * move that to a global limit here. We may be able to remove this 172 * code, needs testing. 173 */ 174 if (max_dev_transactions > 256) 175 max_dev_transactions = 256; 176 if (max_tagged_dev_transactions > 256) 177 max_tagged_dev_transactions = 256; 178 179 /* 180 * Allocate a simq or use the supplied (possibly shared) simq. 181 */ 182 if (queue == NULL) 183 queue = cam_simq_alloc(max_tagged_dev_transactions); 184 else 185 cam_devq_reference(queue); 186 187 if (lock == NULL) 188 return (NULL); 189 190 sim = kmalloc(sizeof(struct cam_sim), M_CAMSIM, M_INTWAIT | M_ZERO); 191 sim->sim_action = sim_action; 192 sim->sim_poll = sim_poll; 193 sim->sim_name = sim_name; 194 sim->softc = softc; 195 sim->path_id = CAM_PATH_ANY; 196 sim->unit_number = unit; 197 sim->bus_id = 0; /* set in xpt_bus_register */ 198 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 199 sim->max_dev_openings = max_dev_transactions; 200 sim->flags = 0; 201 sim->refcount = 1; 202 sim->devq = queue; 203 sim->lock = lock; 204 if (lock == &sim_mplock) { 205 sim->flags |= 0; 206 callout_init(&sim->callout); 207 } else { 208 sim->flags |= CAM_SIM_MPSAFE; 209 callout_init_mp(&sim->callout); 210 } 211 212 SLIST_INIT(&sim->ccb_freeq); 213 TAILQ_INIT(&sim->sim_doneq); 214 spin_init(&sim->sim_spin); 215 216 return (sim); 217 } 218 219 static void deadsim_poll(struct cam_sim *sim); 220 static void deadsim_action(struct cam_sim *sim, union ccb *ccb); 221 222 void 223 cam_sim_free(struct cam_sim *sim) 224 { 225 sim->sim_action = deadsim_action; 226 sim->sim_poll = deadsim_poll; 227 cam_sim_release(sim, CAM_SIM_SOFTC); 228 } 229 230 /* 231 * Note: the devq is still used by individual peripherals even if the 232 * backend sim disappears, so do not destroy it until the sim itself 233 * is no longer needed. 234 */ 235 void 236 cam_sim_release(struct cam_sim *sim, int flags) 237 { 238 if (flags & CAM_SIM_SOFTC) 239 sim->softc = NULL; 240 if (sim->refcount == 1) { 241 if (sim->devq) { 242 cam_simq_release(sim->devq); 243 sim->devq = NULL; 244 } 245 sim->refcount = 0; 246 kfree(sim, M_CAMSIM); 247 } else { 248 --sim->refcount; 249 } 250 } 251 252 void 253 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 254 { 255 sim->path_id = path_id; 256 } 257 258 /* 259 * Dead sim poll and action functions. The backend to the sim has gone 260 * away, aka usb, scsi device, etc... deal with it. 261 */ 262 static void 263 deadsim_poll(struct cam_sim *sim) 264 { 265 /* empty */ 266 } 267 268 static void 269 deadsim_action(struct cam_sim *sim, union ccb *ccb) 270 { 271 ccb->ccb_h.status = CAM_TID_INVALID; 272 xpt_done(ccb); 273 } 274 275