FreeBSD/Linux Kernel Cross Reference
sys/cam/cam_sim.c

     /*-
      * Common functions for SCSI Interface Modules (SIMs).
      *
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 1997 Justin T. Gibbs.
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions, and the following disclaimer,
     *    without modification, immediately at the beginning of the file.
     * 2. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/12.0/sys/cam/cam_sim.c 326265 2017-11-27 15:12:43Z pfg $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    
    #include <cam/cam.h>
    #include <cam/cam_ccb.h>
    #include <cam/cam_sim.h>
    #include <cam/cam_queue.h>
    #include <cam/cam_xpt.h>
    
    #define CAM_PATH_ANY (u_int32_t)-1
    
    static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
    
    static struct mtx cam_sim_free_mtx;
    MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock", MTX_DEF);
    
    struct cam_devq *
    cam_simq_alloc(u_int32_t max_sim_transactions)
    {
            return (cam_devq_alloc(/*size*/0, max_sim_transactions));
    }
    
    void
    cam_simq_free(struct cam_devq *devq)
    {
            cam_devq_free(devq);
    }
    
    struct cam_sim *
    cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
                  const char *sim_name, void *softc, u_int32_t unit,
                  struct mtx *mtx, int max_dev_transactions,
                  int max_tagged_dev_transactions, struct cam_devq *queue)
    {
            struct cam_sim *sim;
    
            sim = (struct cam_sim *)malloc(sizeof(struct cam_sim),
                M_CAMSIM, M_ZERO | M_NOWAIT);
    
            if (sim == NULL)
                    return (NULL);
    
            sim->sim_action = sim_action;
            sim->sim_poll = sim_poll;
            sim->sim_name = sim_name;
            sim->softc = softc;
            sim->path_id = CAM_PATH_ANY;
            sim->unit_number = unit;
            sim->bus_id = 0;        /* set in xpt_bus_register */
            sim->max_tagged_dev_openings = max_tagged_dev_transactions;
            sim->max_dev_openings = max_dev_transactions;
            sim->flags = 0;
            sim->refcount = 1;
            sim->devq = queue;
            sim->mtx = mtx;
            if (mtx == &Giant) {
                    sim->flags |= 0;
                    callout_init(&sim->callout, 0);
            } else {
                    sim->flags |= CAM_SIM_MPSAFE;
                    callout_init(&sim->callout, 1);
            }
           return (sim);
   }
   
   void
   cam_sim_free(struct cam_sim *sim, int free_devq)
   {
           struct mtx *mtx = sim->mtx;
           int error;
   
           if (mtx) {
                   mtx_assert(mtx, MA_OWNED);
           } else {
                   mtx = &cam_sim_free_mtx;
                   mtx_lock(mtx);
           }
           sim->refcount--;
           if (sim->refcount > 0) {
                   error = msleep(sim, mtx, PRIBIO, "simfree", 0);
                   KASSERT(error == 0, ("invalid error value for msleep(9)"));
           }
           KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
           if (sim->mtx == NULL)
                   mtx_unlock(mtx);
   
           if (free_devq)
                   cam_simq_free(sim->devq);
           free(sim, M_CAMSIM);
   }
   
   void
   cam_sim_release(struct cam_sim *sim)
   {
           struct mtx *mtx = sim->mtx;
   
           if (mtx) {
                   if (!mtx_owned(mtx))
                           mtx_lock(mtx);
                   else
                           mtx = NULL;
           } else {
                   mtx = &cam_sim_free_mtx;
                   mtx_lock(mtx);
           }
           KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
           sim->refcount--;
           if (sim->refcount == 0)
                   wakeup(sim);
           if (mtx)
                   mtx_unlock(mtx);
   }
   
   void
   cam_sim_hold(struct cam_sim *sim)
   {
           struct mtx *mtx = sim->mtx;
   
           if (mtx) {
                   if (!mtx_owned(mtx))
                           mtx_lock(mtx);
                   else
                           mtx = NULL;
           } else {
                   mtx = &cam_sim_free_mtx;
                   mtx_lock(mtx);
           }
           KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
           sim->refcount++;
           if (mtx)
                   mtx_unlock(mtx);
   }
   
   void
   cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id)
   {
           sim->path_id = path_id;
   }

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