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 #include <sys/thread2.h> 39 #include <sys/spinlock2.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 /* 73 * lock can be NULL if sim was &dead_sim 74 */ 75 void 76 sim_lock_assert_owned(sim_lock *lock) 77 { 78 if (lock) { 79 if (lock == &sim_mplock) 80 ASSERT_MP_LOCK_HELD(curthread); 81 else 82 KKASSERT(lockstatus(lock, curthread) != 0); 83 } 84 } 85 86 void 87 sim_lock_assert_unowned(sim_lock *lock) 88 { 89 if (lock) { 90 if (lock != &sim_mplock) 91 KKASSERT(lockstatus(lock, curthread) == 0); 92 } 93 } 94 95 int 96 sim_lock_sleep(void *ident, int flags, const char *wmesg, int timo, 97 sim_lock *lock) 98 { 99 int retval; 100 101 if (lock != &sim_mplock) { 102 /* lock should be held already */ 103 KKASSERT(lockstatus(lock, curthread) != 0); 104 tsleep_interlock(ident, flags); 105 lockmgr(lock, LK_RELEASE); 106 retval = tsleep(ident, flags | PINTERLOCKED, wmesg, timo); 107 } else { 108 retval = tsleep(ident, flags, wmesg, timo); 109 } 110 111 if (lock != &sim_mplock) { 112 lockmgr(lock, LK_EXCLUSIVE); 113 } 114 115 return (retval); 116 } 117 118 struct cam_devq * 119 cam_simq_alloc(u_int32_t max_sim_transactions) 120 { 121 return (cam_devq_alloc(/*size*/0, max_sim_transactions)); 122 } 123 124 void 125 cam_simq_release(struct cam_devq *devq) 126 { 127 cam_devq_release(devq); 128 } 129 130 /* 131 * cam_sim_alloc() may potentially be called from an interrupt (?) but 132 * unexpected things happen to the system if malloc() returns NULL so we 133 * use M_INTWAIT anyway. 134 */ 135 struct cam_sim * 136 cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, 137 const char *sim_name, void *softc, u_int32_t unit, 138 sim_lock *lock, int max_dev_transactions, 139 int max_tagged_dev_transactions, struct cam_devq *queue) 140 { 141 struct cam_sim *sim; 142 143 /* 144 * XXX ahd was limited to 256 instead of 512 for unknown reasons, 145 * move that to a global limit here. We may be able to remove this 146 * code, needs testing. 147 */ 148 if (max_dev_transactions > 256) 149 max_dev_transactions = 256; 150 if (max_tagged_dev_transactions > 256) 151 max_tagged_dev_transactions = 256; 152 153 /* 154 * Allocate a simq or use the supplied (possibly shared) simq. 155 */ 156 if (queue == NULL) 157 queue = cam_simq_alloc(max_tagged_dev_transactions); 158 else 159 cam_devq_reference(queue); 160 161 if (lock == NULL) 162 return (NULL); 163 164 sim = kmalloc(sizeof(struct cam_sim), M_CAMSIM, M_INTWAIT | M_ZERO); 165 sim->sim_action = sim_action; 166 sim->sim_poll = sim_poll; 167 sim->sim_name = sim_name; 168 sim->softc = softc; 169 sim->path_id = CAM_PATH_ANY; 170 sim->unit_number = unit; 171 sim->bus_id = 0; /* set in xpt_bus_register */ 172 sim->max_tagged_dev_openings = max_tagged_dev_transactions; 173 sim->max_dev_openings = max_dev_transactions; 174 sim->flags = 0; 175 sim->refcount = 1; 176 sim->devq = queue; 177 sim->lock = lock; 178 if (lock == &sim_mplock) { 179 sim->flags |= 0; 180 callout_init(&sim->callout); 181 } else { 182 sim->flags |= CAM_SIM_MPSAFE; 183 callout_init_mp(&sim->callout); 184 } 185 186 SLIST_INIT(&sim->ccb_freeq); 187 TAILQ_INIT(&sim->sim_doneq); 188 spin_init(&sim->sim_spin); 189 190 return (sim); 191 } 192 193 static void deadsim_poll(struct cam_sim *sim); 194 static void deadsim_action(struct cam_sim *sim, union ccb *ccb); 195 196 void 197 cam_sim_free(struct cam_sim *sim) 198 { 199 sim->sim_action = deadsim_action; 200 sim->sim_poll = deadsim_poll; 201 cam_sim_release(sim, CAM_SIM_SOFTC); 202 } 203 204 /* 205 * Note: the devq is still used by individual peripherals even if the 206 * backend sim disappears, so do not destroy it until the sim itself 207 * is no longer needed. 208 */ 209 void 210 cam_sim_release(struct cam_sim *sim, int flags) 211 { 212 if (flags & CAM_SIM_SOFTC) 213 sim->softc = NULL; 214 if (sim->refcount == 1) { 215 if (sim->devq) { 216 cam_simq_release(sim->devq); 217 sim->devq = NULL; 218 } 219 sim->refcount = 0; 220 kfree(sim, M_CAMSIM); 221 } else { 222 --sim->refcount; 223 } 224 } 225 226 void 227 cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) 228 { 229 sim->path_id = path_id; 230 } 231 232 /* 233 * Dead sim poll and action functions. The backend to the sim has gone 234 * away, aka usb, scsi device, etc... deal with it. 235 */ 236 static void 237 deadsim_poll(struct cam_sim *sim) 238 { 239 /* empty */ 240 } 241 242 static void 243 deadsim_action(struct cam_sim *sim, union ccb *ccb) 244 { 245 ccb->ccb_h.status = CAM_TID_INVALID; 246 xpt_done(ccb); 247 } 248 249