sys/bus/cam/cam_sim.c

   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