/*-
* Common functions for SCSI Interface Modules (SIMs).
*
* SPDX-License-Identifier: BSD-2-Clause
*
* 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>
#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 (uint32_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(uint32_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);
}
/**
* @brief allocate a new sim and fill in the details
*
* A Storage Interface Module (SIM) is the interface between CAM and
* hardware. SIM receives CCBs from CAM via @p sim_action callback and
* translates them into DMA or other hardware transactions. During system
* dumps, it can be polled with the @p sim_poll callback. CCB processing is
* terminated by calling @c xpt_done().
*
* The @p mtx acts as a perimeter lock for the SIM. All calls into the SIM's
* @p sim_action are made with this lock held. It is also used to hold/release
* a SIM, managing its reference count. When the lock is NULL, the SIM is 100%
* responsible for locking (and the reference counting is done with a shared
* lock.
*
* The cam_devq passed in (@c queue) is used to arbitrate the number of
* outstanding transactions to the SIM. For HBAs that have global limits shared
* between the different buses, the same devq should be specified for each bus
* attached to the SIM.
*
* @param sim_action Function to call to process CCBs
* @param sim_poll Function to poll the hardware for completions
* @param sim_name Name of SIM class
* @param softc Software context associated with the SIM
* @param unit Unit number of SIM
* @param mtx Mutex to lock while interacting with the SIM, or NULL
* for a SIM that handle its own locking to enable multi
* queue support.
* @param max_dev_transactions Maximum number of concurrent untagged
* transactions possible
* @param max_tagged_dev_transactions Maximum number of concurrent tagged
* transactions possible.
* @param queue The cam_devq to use for this SIM.
*/
struct cam_sim *
cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll,
const char *sim_name, void *softc, uint32_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);
}
/**
* @brief frees up the sim
*
* Frees up the CAM @c sim and optionally the devq. If a mutex is associated
* with the sim, it must be locked on entry. It will remain locked on
* return.
*
* This function will wait for all outstanding reference to the sim to clear
* before returning.
*
* @param sim The sim to free
* @param free_devq Free the devq associated with the sim at creation.
*/
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, uint32_t path_id)
{
sim->path_id = path_id;
}
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