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/spinlock2.h> 39 #include <sys/mplock2.h> 40 41 #include "cam.h" 42 #include "cam_ccb.h" 43 #include "cam_sim.h" 44 #include "cam_queue.h" 45 #include "cam_xpt_sim.h" 46 47 #define CAM_PATH_ANY (u_int32_t)-1 48 49 MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers"); 50 51 /* Drivers will use sim_mplock if they need the BGL */ 52 sim_lock sim_mplock; 53 54 void 55 cam_sim_lock(sim_lock *lock) 56 { 57 if (lock == &sim_mplock) 58 get_mplock(); 59 else 60 lockmgr(lock, LK_EXCLUSIVE); 61 } 62 63 void 64 cam_sim_unlock(sim_lock *lock) 65 { 66 if (lock == &sim_mplock) 67 rel_mplock(); 68 else 69 lockmgr(lock, LK_RELEASE); 70 } 71 72 int 73 cam_sim_cond_lock(sim_lock *lock) 74 { 75 if (lock == &sim_mplock) { 76 get_mplock(); 77 return(1); 78 } else if (lockstatus(lock, curthread) != LK_EXCLUSIVE) { 79 lockmgr(lock, LK_EXCLUSIVE); 80 return(1); 81 } 82 return(0); 83 } 84 85 void 86 cam_sim_cond_unlock(sim_lock *lock, int doun) 87 { 88 if (doun) { 89 if (lock == &sim_mplock) 90 rel_mplock(); 91 else 92 lockmgr(lock, LK_RELEASE); 93 } 94 } 95 96 /* 97 * lock can be NULL if sim was &dead_sim 98 */ 99 void 100 sim_lock_assert_owned(sim_lock *lock) 101 { 102 if (lock) { 103 if (lock == &sim_mplock) 104 ASSERT_MP_LOCK_HELD(); 105 else 106 KKASSERT(lockstatus(lock, curthread) != 0); 107 } 108 } 109 110 void 111 sim_lock_assert_unowned(sim_lock *lock) 112 { 113 if (lock) { 114 if (lock != &sim_mplock) 115 KKASSERT(lockstatus(lock, curthread) == 0); 116 } 117 } 118 119 int 120 sim_lock_sleep(void *ident, int flags, const char *wmesg, int timo, 121 sim_lock *lock) 122 { 123 int retval; 124 125 if (lock != &sim_mplock) { 126 /* lock should be held already */ 127 KKASSERT(lockstatus(lock, curthread) != 0); 128 tsleep_interlock(ident, flags); 129 lockmgr(lock, LK_RELEASE); 130 retval = tsleep(ident, flags | PINTERLOCKED, wmesg, timo); 131 } else { 132 retval = tsleep(ident, flags, wmesg, timo); 133 } 134 135 if (lock != &sim_mplock) { 136 lockmgr(lock, LK_EXCLUSIVE); 137 } 138 139 return (retval); 140 } 141 142 struct cam_devq * 143 cam_simq_alloc(u_int32_t max_sim_transactions) 144 { 145 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 146 } 147 148 void 149 cam_simq_release(struct cam_devq *devq) 150 { 151 cam_devq_release(devq); 152 } 153 154 /* 155 * cam_sim_alloc() may potentially be called from an interrupt (?) but 156 * unexpected things happen to the system if malloc() returns NULL so we 157 * use M_INTWAIT anyway. 158 */ 159 struct cam_sim * 160 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 161 const char *sim_name, void *softc, u_int32_t unit, 162 sim_lock *lock, int max_dev_transactions, 163 int max_tagged_dev_transactions, struct cam_devq *queue) 164 { 165 struct cam_sim *sim; 166 167 /* 168 * XXX ahd was limited to 256 instead of 512 for unknown reasons, 169 * move that to a global limit here. We may be able to remove this 170 * code, needs testing. 171 */ 172 if (max_dev_transactions > 256) 173 max_dev_transactions = 256; 174 if (max_tagged_dev_transactions > 256) 175 max_tagged_dev_transactions = 256; 176 177 /* 178 * Allocate a simq or use the supplied (possibly shared) simq. 179 */ 180 if (queue == NULL) 181 queue = cam_simq_alloc(max_tagged_dev_transactions); 182 else 183 cam_devq_reference(queue); 184 185 if (lock == NULL) 186 return (NULL); 187 188 sim = kmalloc(sizeof(struct cam_sim), M_CAMSIM, M_INTWAIT | M_ZERO); 189 sim->sim_action = sim_action; 190 sim->sim_poll = sim_poll; 191 sim->sim_name = sim_name; 192 sim->softc = softc; 193 sim->path_id = CAM_PATH_ANY; 194 sim->unit_number = unit; 195 sim->bus_id = 0; /* set in xpt_bus_register */ 196 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 197 sim->max_dev_openings = max_dev_transactions; 198 sim->flags = 0; 199 sim->refcount = 1; 200 sim->devq = queue; 201 sim->lock = lock; 202 if (lock == &sim_mplock) { 203 sim->flags |= 0; 204 callout_init(&sim->callout); 205 } else { 206 sim->flags |= CAM_SIM_MPSAFE; 207 callout_init_mp(&sim->callout); 208 } 209 210 SLIST_INIT(&sim->ccb_freeq); 211 TAILQ_INIT(&sim->sim_doneq); 212 spin_init(&sim->sim_spin, "cam_sim_alloc"); 213 214 return (sim); 215 } 216 217 void 218 cam_sim_set_max_tags(struct cam_sim *sim, int max_tags) 219 { 220 if (max_tags > 256) 221 max_tags = 256; 222 sim->max_tagged_dev_openings = max_tags; 223 cam_devq_set_openings(sim->devq, max_tags); 224 } 225 226 static void deadsim_poll(struct cam_sim *sim); 227 static void deadsim_action(struct cam_sim *sim, union ccb *ccb); 228 229 void 230 cam_sim_free(struct cam_sim *sim) 231 { 232 sim->sim_action = deadsim_action; 233 sim->sim_poll = deadsim_poll; 234 cam_sim_release(sim, CAM_SIM_SOFTC); 235 } 236 237 /* 238 * Note: the devq is still used by individual peripherals even if the 239 * backend sim disappears, so do not destroy it until the sim itself 240 * is no longer needed. 241 */ 242 void 243 cam_sim_release(struct cam_sim *sim, int flags) 244 { 245 if (flags & CAM_SIM_SOFTC) 246 sim->softc = NULL; 247 if (sim->refcount == 1) { 248 if (sim->devq) { 249 cam_simq_release(sim->devq); 250 sim->devq = NULL; 251 } 252 sim->refcount = 0; 253 kfree(sim, M_CAMSIM); 254 } else { 255 --sim->refcount; 256 } 257 } 258 259 void 260 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 261 { 262 sim->path_id = path_id; 263 } 264 265 /* 266 * Dead sim poll and action functions. The backend to the sim has gone 267 * away, aka usb, scsi device, etc... deal with it. 268 */ 269 static void 270 deadsim_poll(struct cam_sim *sim) 271 { 272 /* empty */ 273 } 274 275 static void 276 deadsim_action(struct cam_sim *sim, union ccb *ccb) 277 { 278 ccb->ccb_h.status = CAM_TID_INVALID; 279 xpt_done(ccb); 280 } 281 282