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/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