scsi_targ_bh.c

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/*
 * Implementation of the Target Mode 'Black Hole device' for CAM.
 *
 * Copyright (c) 1999 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_targ_bh.c,v 1.1.2.1 1999/03/07 00:40:31 gibbs Exp $
 */
#include <stddef.h>	/* For offsetof */

#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/conf.h>
#include <sys/devicestat.h>
#include <sys/malloc.h>
#include <sys/uio.h>

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

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

typedef enum {
	TARGBH_STATE_NORMAL,
	TARGBH_STATE_EXCEPTION,
	TARGBH_STATE_TEARDOWN
} targbh_state;

typedef enum {
	TARGBH_FLAG_NONE	 = 0x00,
	TARGBH_FLAG_LUN_ENABLED	 = 0x01
} targbh_flags;

typedef enum {
	TARGBH_CCB_WORKQ,
	TARGBH_CCB_WAITING
} targbh_ccb_types;

#define MAX_ACCEPT	8
#define MAX_IMMEDIATE	16
#define MAX_BUF_SIZE	256	/* Max inquiry/sense/mode page transfer */

#define MIN(a, b) ((a > b) ? b : a)

/* Offsets into our private CCB area for storing accept information */
#define ccb_type	ppriv_field0
#define ccb_descr	ppriv_ptr1

/* We stick a pointer to the originating accept TIO in each continue I/O CCB */
#define ccb_atio	ppriv_ptr1

TAILQ_HEAD(ccb_queue, ccb_hdr);

struct targbh_softc {
	struct		ccb_queue pending_queue;
	struct		ccb_queue work_queue;
	struct		ccb_queue unknown_atio_queue;
	struct		devstat device_stats;
	targbh_state	state;
	targbh_flags	flags;	
	u_int		init_level;
	u_int		inq_data_len;
	struct		ccb_accept_tio *accept_tio_list;
	struct		ccb_hdr_slist immed_notify_slist;
};

struct targbh_cmd_desc {
	struct	  ccb_accept_tio* atio_link;
	u_int	  data_resid;	/* How much left to transfer */
	u_int	  data_increment;/* Amount to send before next disconnect */
	void*	  data;		/* The data. Can be from backing_store or not */
	void*	  backing_store;/* Backing store allocated for this descriptor*/
	u_int	  max_size;	/* Size of backing_store */
	u_int32_t timeout;	
	u_int8_t  status;	/* Status to return to initiator */
};

static struct scsi_inquiry_data no_lun_inq_data =
{
	T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
	/* version */2, /* format version */2
};

static struct scsi_sense_data no_lun_sense_data =
{
	SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
	0,
	SSD_KEY_NOT_READY, 
	{ 0, 0, 0, 0 },
	/*extra_len*/offsetof(struct scsi_sense_data, fru)
                   - offsetof(struct scsi_sense_data, extra_len),
	{ 0, 0, 0, 0 },
	/* Logical Unit Not Supported */
	/*ASC*/0x25, /*ASCQ*/0
};

static const int request_sense_size = offsetof(struct scsi_sense_data, fru);

static periph_init_t	targbhinit;
static void		targbhasync(void *callback_arg, u_int32_t code,
				    struct cam_path *path, void *arg);
static cam_status	targbhenlun(struct cam_periph *periph);
static cam_status	targbhdislun(struct cam_periph *periph);
static periph_ctor_t	targbhctor;
static periph_dtor_t	targbhdtor;
static periph_start_t	targbhstart;
static void		targbhdone(struct cam_periph *periph,
				   union ccb *done_ccb);
#ifdef NOTYET
static  int		targbherror(union ccb *ccb, u_int32_t cam_flags,
				    u_int32_t sense_flags);
#endif
static struct targbh_cmd_desc*	targbhallocdescr(void);
static void		targbhfreedescr(struct targbh_cmd_desc *buf);
					
static struct periph_driver targbhdriver =
{
	targbhinit, "targbh",
	TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
};

DATA_SET(periphdriver_set, targbhdriver);

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

	/*
	 * Install a global async callback.  This callback will
	 * receive async callbacks like "new path registered".
	 */
	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_PATH_REGISTERED;
		csa.callback = targbhasync;
		csa.callback_arg = NULL;
		xpt_action((union ccb *)&csa);
		status = csa.ccb_h.status;
		xpt_free_path(path);
        }

	if (status != CAM_REQ_CMP) {
		printf("targbh: Failed to attach master async callback "
		       "due to status 0x%x!\n", status);
	}
}

static void
targbhasync(void *callback_arg, u_int32_t code,
	    struct cam_path *path, void *arg)
{
	struct cam_periph *periph;

	periph = (struct cam_periph *)callback_arg;
	switch (code) {
	case AC_PATH_REGISTERED:
	{
		struct ccb_pathinq *cpi;
		struct cam_path *new_path;
		cam_status status;
 
		cpi = (struct ccb_pathinq *)arg;

		/* Only attach to controllers that support target mode */
		if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
			break;

		/*
		 * Allocate a peripheral instance for
		 * this target instance.
		 */
		status = xpt_create_path(&new_path, NULL,
					 xpt_path_path_id(path),
					 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
		if (status != CAM_REQ_CMP) {
			printf("targbhasync: Unable to create path "
				"due to status 0x%x\n", status);
			break;
		}
		status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
					  targbhstart,
					  "targbh", CAM_PERIPH_BIO,
					  new_path, targbhasync,
					  AC_PATH_REGISTERED,
					  cpi);
		xpt_free_path(new_path);
		if (status != CAM_REQ_CMP
		 && status != CAM_REQ_INPROG)
			printf("targbhasync: Unable to allocate new periph "
			       "due to status 0x%x\n", status);
		break;
	}
	case AC_PATH_DEREGISTERED:
	{
		targbhdislun(periph);
		break;
	}
	default:
		break;
	}
}

/* Attempt to enable our lun */
static cam_status
targbhenlun(struct cam_periph *periph)
{
	union ccb immed_ccb;
	struct targbh_softc *softc;
	cam_status status;
	int i;

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

	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
		return (CAM_REQ_CMP);

	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, /*priority*/1);
	immed_ccb.ccb_h.func_code = XPT_EN_LUN;

	/* Don't need support for any vendor specific commands */
	immed_ccb.cel.grp6_len = 0;
	immed_ccb.cel.grp7_len = 0;
	immed_ccb.cel.enable = 1;
	xpt_action(&immed_ccb);
	status = immed_ccb.ccb_h.status;
	if (status != CAM_REQ_CMP) {
		xpt_print_path(periph->path);
		printf("targbhenlun - Enable Lun Rejected for status 0x%x\n",
		       status);
		return (status);
	}
	
	softc->flags |= TARGBH_FLAG_LUN_ENABLED;

	/*
	 * Build up a buffer of accept target I/O
	 * operations for incoming selections.
	 */
	for (i = 0; i < MAX_ACCEPT; i++) {
		struct ccb_accept_tio *atio;

		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_DEVBUF,
						      M_NOWAIT);
		if (atio == NULL) {
			status = CAM_RESRC_UNAVAIL;
			break;
		}

		atio->ccb_h.ccb_descr = targbhallocdescr();

		if (atio->ccb_h.ccb_descr == NULL) {
			free(atio, M_DEVBUF);
			status = CAM_RESRC_UNAVAIL;
			break;
		}

		xpt_setup_ccb(&atio->ccb_h, periph->path, /*priority*/1);
		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
		atio->ccb_h.cbfcnp = targbhdone;
		xpt_action((union ccb *)atio);
		status = atio->ccb_h.status;
		if (status != CAM_REQ_INPROG) {
			targbhfreedescr(atio->ccb_h.ccb_descr);
			free(atio, M_DEVBUF);
			break;
		}
		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
		    softc->accept_tio_list;
		softc->accept_tio_list = atio;
	}

	if (i == 0) {
		xpt_print_path(periph->path);
		printf("targbhenlun - Could not allocate accept tio CCBs: "
		       "status = 0x%x\n", status);
		targbhdislun(periph);
		return (CAM_REQ_CMP_ERR);
	}

	/*
	 * Build up a buffer of immediate notify CCBs
	 * so the SIM can tell us of asynchronous target mode events.
	 */
	for (i = 0; i < MAX_ACCEPT; i++) {
		struct ccb_immed_notify *inot;

		inot = (struct ccb_immed_notify*)malloc(sizeof(*inot), M_DEVBUF,
						        M_NOWAIT);

		if (inot == NULL) {
			status = CAM_RESRC_UNAVAIL;
			break;
		}

		xpt_setup_ccb(&inot->ccb_h, periph->path, /*priority*/1);
		inot->ccb_h.func_code = XPT_IMMED_NOTIFY;
		inot->ccb_h.cbfcnp = targbhdone;
		xpt_action((union ccb *)inot);
		status = inot->ccb_h.status;
		if (status != CAM_REQ_INPROG) {
			free(inot, M_DEVBUF);
			break;
		}
		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
				  periph_links.sle);
	}

	if (i == 0) {
		xpt_print_path(periph->path);
		printf("targbhenlun - Could not allocate immediate notify "
		       "CCBs: status = 0x%x\n", status);
		targbhdislun(periph);
		return (CAM_REQ_CMP_ERR);
	}

	return (CAM_REQ_CMP);
}

static cam_status
targbhdislun(struct cam_periph *periph)
{
	union ccb ccb;
	struct targbh_softc *softc;