cam_sim.c

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/*-
 * 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("$FreeBSD$");
 
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
 
#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_queue.h>
#include <cam/cam_sim.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 = 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;
        return (sim);
}
 
void
cam_sim_free(struct cam_sim *sim, int free_devq)
{
        struct mtx *mtx;
        int error __diagused;
 
        if (sim->mtx == NULL) {
                mtx = &cam_sim_free_mtx;
                mtx_lock(mtx);
        } else {
                mtx = sim->mtx;
                mtx_assert(mtx, MA_OWNED);
        }
        KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
        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 (mtx == &cam_sim_free_mtx)   /* 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;
 
        if (sim->mtx == NULL)
                mtx = &cam_sim_free_mtx;
        else if (!mtx_owned(sim->mtx))
                mtx = sim->mtx;
        else
                mtx = NULL;     /* We hold the lock. */
        if (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;
 
        if (sim->mtx == NULL)
                mtx = &cam_sim_free_mtx;
        else if (!mtx_owned(sim->mtx))
                mtx = sim->mtx;
        else
                mtx = NULL;     /* We hold the lock. */
        if (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;
}