scsi_pt.c

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/*
 * Implementation of SCSI Processor Target Peripheral driver for CAM.
 *
 * Copyright (c) 1998 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.
 *
 *      $Id: scsi_pt.c,v 1.4.2.2 1999/05/09 01:27:42 ken Exp $
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/buf.h>
#include <sys/devicestat.h>
#include <sys/malloc.h>
#include <sys/conf.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_extend.h>
#include <cam/cam_periph.h>
#include <cam/cam_xpt_periph.h>
#include <cam/cam_debug.h>

#include <cam/scsi/scsi_all.h>
#include <cam/scsi/scsi_message.h>
#include <cam/scsi/scsi_pt.h>

typedef enum {
	PT_STATE_PROBE,
	PT_STATE_NORMAL
} pt_state;

typedef enum {
	PT_FLAG_NONE		= 0x00,
	PT_FLAG_OPEN		= 0x01,
	PT_FLAG_DEVICE_INVALID	= 0x02,
	PT_FLAG_RETRY_UA	= 0x04
} pt_flags;

typedef enum {
	PT_CCB_BUFFER_IO	= 0x01,
	PT_CCB_WAITING		= 0x02,
	PT_CCB_RETRY_UA		= 0x04,
	PT_CCB_BUFFER_IO_UA	= PT_CCB_BUFFER_IO|PT_CCB_RETRY_UA
} pt_ccb_state;

/* Offsets into our private area for storing information */
#define ccb_state	ppriv_field0
#define ccb_bp		ppriv_ptr1

struct pt_softc {
	struct	 buf_queue_head buf_queue;
	struct	 devstat device_stats;
	LIST_HEAD(, ccb_hdr) pending_ccbs;
	pt_state state;
	pt_flags flags;	
	union	 ccb saved_ccb;
};

static	d_open_t	ptopen;
static	d_read_t	ptread;
static	d_write_t	ptwrite;
static	d_close_t	ptclose;
static	d_strategy_t	ptstrategy;
static	periph_init_t	ptinit;
static	void		ptasync(void *callback_arg, u_int32_t code,
				struct cam_path *path, void *arg);
static	periph_ctor_t	ptctor;
static	periph_oninv_t	ptoninvalidate;
static	periph_dtor_t	ptdtor;
static	periph_start_t	ptstart;
static	void		ptdone(struct cam_periph *periph,
			       union ccb *done_ccb);
static  int		pterror(union ccb *ccb, u_int32_t cam_flags,
				u_int32_t sense_flags);

void	scsi_send_receive(struct ccb_scsiio *csio, u_int32_t retries,
			  void (*cbfcnp)(struct cam_periph *, union ccb *),
			  u_int tag_action, int readop, u_int byte2,
			  u_int32_t xfer_len, u_int8_t *data_ptr,
			  u_int8_t sense_len, u_int32_t timeout);

static struct periph_driver ptdriver =
{
	ptinit, "pt",
	TAILQ_HEAD_INITIALIZER(ptdriver.units), /* generation */ 0
};

DATA_SET(periphdriver_set, ptdriver);

#define PT_CDEV_MAJOR 61

static struct cdevsw pt_cdevsw = 
{
	/*d_open*/	ptopen,
	/*d_close*/	ptclose,
	/*d_read*/	ptread,
	/*d_write*/	ptwrite,
	/*d_ioctl*/	noioctl,
	/*d_stop*/	nostop,
	/*d_reset*/	noreset,
	/*d_devtotty*/	nodevtotty,
	/*d_poll*/	seltrue,
	/*d_mmap*/	nommap,
	/*d_strategy*/	ptstrategy,
	/*d_name*/	"pt",
	/*d_spare*/	NULL,
	/*d_maj*/	-1,
	/*d_dump*/	nodump,
	/*d_psize*/	nopsize,
	/*d_flags*/	0,
	/*d_maxio*/	0,
	/*b_maj*/	-1
};

static struct extend_array *ptperiphs;

static int
ptopen(dev_t dev, int flags, int fmt, struct proc *p)
{
	struct cam_periph *periph;
	struct pt_softc *softc;
	int unit;
	int error;
	int s;

	unit = minor(dev);
	periph = cam_extend_get(ptperiphs, unit);
	if (periph == NULL)
		return (ENXIO);	

	softc = (struct pt_softc *)periph->softc;

	s = splsoftcam();
	if (softc->flags & PT_FLAG_DEVICE_INVALID) {
		splx(s);
		return(ENXIO);
	}

	CAM_DEBUG(periph->path, CAM_DEBUG_TRACE,
	    ("ptopen: dev=0x%x (unit %d)\n", dev, unit));

	if ((error = cam_periph_lock(periph, PRIBIO|PCATCH)) != 0) {
		splx(s);
		return (error); /* error code from tsleep */
	}

	splx(s);

	if ((softc->flags & PT_FLAG_OPEN) == 0) {
		if (cam_periph_acquire(periph) != CAM_REQ_CMP)
			error = ENXIO;
		else
			softc->flags |= PT_FLAG_OPEN;
	} else
		error = EBUSY;

	cam_periph_unlock(periph);
	return (error);
}

static int
ptclose(dev_t dev, int flag, int fmt, struct proc *p)
{
	struct	cam_periph *periph;
	struct	pt_softc *softc;
	int	unit;
	int	error;

	unit = minor(dev);
	periph = cam_extend_get(ptperiphs, unit);
	if (periph == NULL)
		return (ENXIO);	

	softc = (struct pt_softc *)periph->softc;

	if ((error = cam_periph_lock(periph, PRIBIO)) != 0)
		return (error); /* error code from tsleep */

	softc->flags &= ~PT_FLAG_OPEN;
	cam_periph_unlock(periph);
	cam_periph_release(periph);
	return (0);
}

static int
ptread(dev_t dev, struct uio *uio, int ioflag)
{
	return(physio(ptstrategy, NULL, dev, 1, minphys, uio));
}

static int
ptwrite(dev_t dev, struct uio *uio, int ioflag)
{
	return(physio(ptstrategy, NULL, dev, 0, minphys, uio));
}

/*
 * Actually translate the requested transfer into one the physical driver
 * can understand.  The transfer is described by a buf and will include
 * only one physical transfer.
 */
static void
ptstrategy(struct buf *bp)
{
	struct cam_periph *periph;
	struct pt_softc *softc;
	u_int  unit;
	int    s;
	
	unit = minor(bp->b_dev);
	periph = cam_extend_get(ptperiphs, unit);
	if (periph == NULL) {
		bp->b_error = ENXIO;
		goto bad;		
	}
	softc = (struct pt_softc *)periph->softc;

	/*
	 * Mask interrupts so that the pack cannot be invalidated until
	 * after we are in the queue.  Otherwise, we might not properly
	 * clean up one of the buffers.
	 */
	s = splbio();
	
	/*
	 * If the device has been made invalid, error out
	 */
	if ((softc->flags & PT_FLAG_DEVICE_INVALID)) {
		splx(s);
		bp->b_error = ENXIO;
		goto bad;
	}
	
	/*
	 * Place it in the queue of disk activities for this disk
	 */
	bufq_insert_tail(&softc->buf_queue, bp);

	splx(s);
	
	/*
	 * Schedule ourselves for performing the work.
	 */
	xpt_schedule(periph, /* XXX priority */1);

	return;
bad:
	bp->b_flags |= B_ERROR;

	/*
	 * Correctly set the buf to indicate a completed xfer
	 */
	bp->b_resid = bp->b_bcount;
	biodone(bp);
}

static void
ptinit(void)
{
	cam_status status;
	struct cam_path *path;

	/*
	 * Create our extend array for storing the devices we attach to.
	 */
	ptperiphs = cam_extend_new();
	if (ptperiphs == NULL) {
		printf("pt: Failed to alloc extend array!\n");
		return;
	}
	
	/*
	 * Install a global async callback.  This callback will
	 * receive async callbacks like "new device found".
	 */
	status = xpt_create_path(&path, /*periph*/NULL, CAM_XPT_PATH_ID,
				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);

	if (status == CAM_REQ_CMP) {
		struct ccb_setasync csa;

                xpt_setup_ccb(&csa.ccb_h, path, /*priority*/5);
                csa.ccb_h.func_code = XPT_SASYNC_CB;
                csa.event_enable = AC_FOUND_DEVICE;
                csa.callback = ptasync;
                csa.callback_arg = NULL;
                xpt_action((union ccb *)&csa);
		status = csa.ccb_h.status;
                xpt_free_path(path);
        }

	if (status != CAM_REQ_CMP) {
		printf("pt: Failed to attach master async callback "
		       "due to status 0x%x!\n", status);
	} else {
		/* If we were successfull, register our devsw */
		dev_t dev;

		dev = makedev(PT_CDEV_MAJOR, 0);
		cdevsw_add(&dev,&pt_cdevsw, NULL);
	}
}

static cam_status
ptctor(struct cam_periph *periph, void *arg)
{
	struct pt_softc *softc;
	struct ccb_setasync csa;
	struct ccb_getdev *cgd;

	cgd = (struct ccb_getdev *)arg;
	if (periph == NULL) {
		printf("ptregister: periph was NULL!!\n");
		return(CAM_REQ_CMP_ERR);
	}

	if (cgd == NULL) {
		printf("ptregister: no getdev CCB, can't register device\n");
		return(CAM_REQ_CMP_ERR);
	}

	softc = (struct pt_softc *)malloc(sizeof(*softc),M_DEVBUF,M_NOWAIT);

	if (softc == NULL) {
		printf("daregister: Unable to probe new device. "
		       "Unable to allocate softc\n");				
		return(CAM_REQ_CMP_ERR);
	}

	bzero(softc, sizeof(*softc));
	LIST_INIT(&softc->pending_ccbs);
	softc->state = PT_STATE_NORMAL;
	bufq_init(&softc->buf_queue);

	periph->softc = softc;
	
	cam_extend_set(ptperiphs, periph->unit_number, periph);

	/*
	 * The DA driver supports a blocksize, but
	 * we don't know the blocksize until we do 
	 * a read capacity.  So, set a flag to
	 * indicate that the blocksize is 
	 * unavailable right now.  We'll clear the
	 * flag as soon as we've done a read capacity.
	 */
	devstat_add_entry(&softc->device_stats, "pt",
			  periph->unit_number, 0,
			  DEVSTAT_NO_BLOCKSIZE,