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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /*
     28  * LDoms virtual disk client (vdc) device driver
     29  *
     30  * This driver runs on a guest logical domain and communicates with the virtual
     31  * disk server (vds) driver running on the service domain which is exporting
     32  * virtualized "disks" to the guest logical domain.
     33  *
     34  * The driver can be divided into four sections:
     35  *
     36  * 1) generic device driver housekeeping
     37  *	_init, _fini, attach, detach, ops structures, etc.
     38  *
     39  * 2) communication channel setup
     40  *	Setup the communications link over the LDC channel that vdc uses to
     41  *	talk to the vDisk server. Initialise the descriptor ring which
     42  *	allows the LDC clients to transfer data via memory mappings.
     43  *
     44  * 3) Support exported to upper layers (filesystems, etc)
     45  *	The upper layers call into vdc via strategy(9E) and DKIO(7I)
     46  *	ioctl calls. vdc will copy the data to be written to the descriptor
     47  *	ring or maps the buffer to store the data read by the vDisk
     48  *	server into the descriptor ring. It then sends a message to the
     49  *	vDisk server requesting it to complete the operation.
     50  *
     51  * 4) Handling responses from vDisk server.
     52  *	The vDisk server will ACK some or all of the messages vdc sends to it
     53  *	(this is configured during the handshake). Upon receipt of an ACK
     54  *	vdc will check the descriptor ring and signal to the upper layer
     55  *	code waiting on the IO.
     56  */
     57 
     58 #include <sys/atomic.h>
     59 #include <sys/conf.h>
     60 #include <sys/disp.h>
     61 #include <sys/ddi.h>
     62 #include <sys/dkio.h>
     63 #include <sys/efi_partition.h>
     64 #include <sys/fcntl.h>
     65 #include <sys/file.h>
     66 #include <sys/kstat.h>
     67 #include <sys/mach_descrip.h>
     68 #include <sys/modctl.h>
     69 #include <sys/mdeg.h>
     70 #include <sys/note.h>
     71 #include <sys/open.h>
     72 #include <sys/sdt.h>
     73 #include <sys/stat.h>
     74 #include <sys/sunddi.h>
     75 #include <sys/types.h>
     76 #include <sys/promif.h>
     77 #include <sys/var.h>
     78 #include <sys/vtoc.h>
     79 #include <sys/archsystm.h>
     80 #include <sys/sysmacros.h>
     81 
     82 #include <sys/cdio.h>
     83 #include <sys/dktp/fdisk.h>
     84 #include <sys/dktp/dadkio.h>
     85 #include <sys/mhd.h>
     86 #include <sys/scsi/generic/sense.h>
     87 #include <sys/scsi/impl/uscsi.h>
     88 #include <sys/scsi/impl/services.h>
     89 #include <sys/scsi/targets/sddef.h>
     90 
     91 #include <sys/ldoms.h>
     92 #include <sys/ldc.h>
     93 #include <sys/vio_common.h>
     94 #include <sys/vio_mailbox.h>
     95 #include <sys/vio_util.h>
     96 #include <sys/vdsk_common.h>
     97 #include <sys/vdsk_mailbox.h>
     98 #include <sys/vdc.h>
     99 
    100 #define	VD_OLDVTOC_LIMIT	0x7fffffff
    101 
    102 /*
    103  * function prototypes
    104  */
    105 
    106 /* standard driver functions */
    107 static int	vdc_open(dev_t *dev, int flag, int otyp, cred_t *cred);
    108 static int	vdc_close(dev_t dev, int flag, int otyp, cred_t *cred);
    109 static int	vdc_strategy(struct buf *buf);
    110 static int	vdc_print(dev_t dev, char *str);
    111 static int	vdc_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblk);
    112 static int	vdc_read(dev_t dev, struct uio *uio, cred_t *cred);
    113 static int	vdc_write(dev_t dev, struct uio *uio, cred_t *cred);
    114 static int	vdc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode,
    115 			cred_t *credp, int *rvalp);
    116 static int	vdc_aread(dev_t dev, struct aio_req *aio, cred_t *cred);
    117 static int	vdc_awrite(dev_t dev, struct aio_req *aio, cred_t *cred);
    118 
    119 static int	vdc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd,
    120 			void *arg, void **resultp);
    121 static int	vdc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd);
    122 static int	vdc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd);
    123 static int	vdc_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op,
    124 		    int mod_flags, char *name, caddr_t valuep, int *lengthp);
    125 
    126 /* setup */
    127 static void	vdc_min(struct buf *bufp);
    128 static int	vdc_send(vdc_t *vdc, caddr_t pkt, size_t *msglen);
    129 static int	vdc_do_ldc_init(vdc_t *vdc, vdc_server_t *srvr);
    130 static int	vdc_start_ldc_connection(vdc_t *vdc);
    131 static int	vdc_create_device_nodes(vdc_t *vdc);
    132 static int	vdc_create_device_nodes_efi(vdc_t *vdc);
    133 static int	vdc_create_device_nodes_vtoc(vdc_t *vdc);
    134 static void	vdc_create_io_kstats(vdc_t *vdc);
    135 static void	vdc_create_err_kstats(vdc_t *vdc);
    136 static void	vdc_set_err_kstats(vdc_t *vdc);
    137 static int	vdc_get_md_node(dev_info_t *dip, md_t **mdpp,
    138 		    mde_cookie_t *vd_nodep);
    139 static int	vdc_init_ports(vdc_t *vdc, md_t *mdp, mde_cookie_t vd_nodep);
    140 static void	vdc_fini_ports(vdc_t *vdc);
    141 static void	vdc_switch_server(vdc_t *vdcp);
    142 static int	vdc_do_ldc_up(vdc_t *vdc);
    143 static void	vdc_terminate_ldc(vdc_t *vdc, vdc_server_t *srvr);
    144 static int	vdc_init_descriptor_ring(vdc_t *vdc);
    145 static void	vdc_destroy_descriptor_ring(vdc_t *vdc);
    146 static int	vdc_setup_devid(vdc_t *vdc);
    147 static void	vdc_store_label_efi(vdc_t *, efi_gpt_t *, efi_gpe_t *);
    148 static void	vdc_store_label_vtoc(vdc_t *, struct dk_geom *,
    149 		    struct extvtoc *);
    150 static void	vdc_store_label_unk(vdc_t *vdc);
    151 static boolean_t vdc_is_opened(vdc_t *vdc);
    152 static void	vdc_update_size(vdc_t *vdc, size_t, size_t, size_t);
    153 static int	vdc_update_vio_bsize(vdc_t *vdc, uint32_t);
    154 
    155 /* handshake with vds */
    156 static int		vdc_init_ver_negotiation(vdc_t *vdc, vio_ver_t ver);
    157 static int		vdc_ver_negotiation(vdc_t *vdcp);
    158 static int		vdc_init_attr_negotiation(vdc_t *vdc);
    159 static int		vdc_attr_negotiation(vdc_t *vdcp);
    160 static int		vdc_init_dring_negotiate(vdc_t *vdc);
    161 static int		vdc_dring_negotiation(vdc_t *vdcp);
    162 static int		vdc_send_rdx(vdc_t *vdcp);
    163 static int		vdc_rdx_exchange(vdc_t *vdcp);
    164 static boolean_t	vdc_is_supported_version(vio_ver_msg_t *ver_msg);
    165 
    166 /* processing incoming messages from vDisk server */
    167 static void	vdc_process_msg_thread(vdc_t *vdc);
    168 static int	vdc_recv(vdc_t *vdc, vio_msg_t *msgp, size_t *nbytesp);
    169 
    170 static uint_t	vdc_handle_cb(uint64_t event, caddr_t arg);
    171 static int	vdc_process_data_msg(vdc_t *vdc, vio_msg_t *msg);
    172 static int	vdc_handle_ver_msg(vdc_t *vdc, vio_ver_msg_t *ver_msg);
    173 static int	vdc_handle_attr_msg(vdc_t *vdc, vd_attr_msg_t *attr_msg);
    174 static int	vdc_handle_dring_reg_msg(vdc_t *vdc, vio_dring_reg_msg_t *msg);
    175 static int 	vdc_send_request(vdc_t *vdcp, int operation,
    176 		    caddr_t addr, size_t nbytes, int slice, diskaddr_t offset,
    177 		    int cb_type, void *cb_arg, vio_desc_direction_t dir);
    178 static int	vdc_map_to_shared_dring(vdc_t *vdcp, int idx);
    179 static int 	vdc_populate_descriptor(vdc_t *vdcp, int operation,
    180 		    caddr_t addr, size_t nbytes, int slice, diskaddr_t offset,
    181 		    int cb_type, void *cb_arg, vio_desc_direction_t dir);
    182 static int 	vdc_do_sync_op(vdc_t *vdcp, int operation, caddr_t addr,
    183 		    size_t nbytes, int slice, diskaddr_t offset, int cb_type,
    184 		    void *cb_arg, vio_desc_direction_t dir, boolean_t);
    185 
    186 static int	vdc_wait_for_response(vdc_t *vdcp, vio_msg_t *msgp);
    187 static int	vdc_drain_response(vdc_t *vdcp, vio_cb_type_t cb_type,
    188 		    struct buf *buf);
    189 static int	vdc_depopulate_descriptor(vdc_t *vdc, uint_t idx);
    190 static int	vdc_populate_mem_hdl(vdc_t *vdcp, vdc_local_desc_t *ldep);
    191 static int	vdc_verify_seq_num(vdc_t *vdc, vio_dring_msg_t *dring_msg);
    192 
    193 /* dkio */
    194 static int	vd_process_ioctl(dev_t dev, int cmd, caddr_t arg, int mode,
    195 		    int *rvalp);
    196 static int	vd_process_efi_ioctl(void *vdisk, int cmd, uintptr_t arg);
    197 static void	vdc_create_fake_geometry(vdc_t *vdc);
    198 static int	vdc_validate_geometry(vdc_t *vdc);
    199 static void	vdc_validate(vdc_t *vdc);
    200 static void	vdc_validate_task(void *arg);
    201 static int	vdc_null_copy_func(vdc_t *vdc, void *from, void *to,
    202 		    int mode, int dir);
    203 static int	vdc_get_wce_convert(vdc_t *vdc, void *from, void *to,
    204 		    int mode, int dir);
    205 static int	vdc_set_wce_convert(vdc_t *vdc, void *from, void *to,
    206 		    int mode, int dir);
    207 static int	vdc_get_vtoc_convert(vdc_t *vdc, void *from, void *to,
    208 		    int mode, int dir);
    209 static int	vdc_set_vtoc_convert(vdc_t *vdc, void *from, void *to,
    210 		    int mode, int dir);
    211 static int	vdc_get_extvtoc_convert(vdc_t *vdc, void *from, void *to,
    212 		    int mode, int dir);
    213 static int	vdc_set_extvtoc_convert(vdc_t *vdc, void *from, void *to,
    214 		    int mode, int dir);
    215 static int	vdc_get_geom_convert(vdc_t *vdc, void *from, void *to,
    216 		    int mode, int dir);
    217 static int	vdc_set_geom_convert(vdc_t *vdc, void *from, void *to,
    218 		    int mode, int dir);
    219 static int	vdc_get_efi_convert(vdc_t *vdc, void *from, void *to,
    220 		    int mode, int dir);
    221 static int	vdc_set_efi_convert(vdc_t *vdc, void *from, void *to,
    222 		    int mode, int dir);
    223 
    224 static void 	vdc_ownership_update(vdc_t *vdc, int ownership_flags);
    225 static int	vdc_access_set(vdc_t *vdc, uint64_t flags, int mode);
    226 static vdc_io_t	*vdc_failfast_io_queue(vdc_t *vdc, struct buf *buf);
    227 static int	vdc_failfast_check_resv(vdc_t *vdc);
    228 
    229 /*
    230  * Module variables
    231  */
    232 
    233 /*
    234  * Tunable variables to control how long vdc waits before timing out on
    235  * various operations
    236  */
    237 static int	vdc_hshake_retries = 3;
    238 
    239 static int	vdc_timeout = 0; /* units: seconds */
    240 static int 	vdc_ldcup_timeout = 1; /* units: seconds */
    241 
    242 static uint64_t vdc_hz_min_ldc_delay;
    243 static uint64_t vdc_min_timeout_ldc = 1 * MILLISEC;
    244 static uint64_t vdc_hz_max_ldc_delay;
    245 static uint64_t vdc_max_timeout_ldc = 100 * MILLISEC;
    246 
    247 static uint64_t vdc_ldc_read_init_delay = 1 * MILLISEC;
    248 static uint64_t vdc_ldc_read_max_delay = 100 * MILLISEC;
    249 
    250 /* values for dumping - need to run in a tighter loop */
    251 static uint64_t	vdc_usec_timeout_dump = 100 * MILLISEC;	/* 0.1s units: ns */
    252 static int	vdc_dump_retries = 100;
    253 
    254 static uint16_t	vdc_scsi_timeout = 60;	/* 60s units: seconds  */
    255 
    256 static uint64_t vdc_ownership_delay = 6 * MICROSEC; /* 6s units: usec */
    257 
    258 /* Count of the number of vdc instances attached */
    259 static volatile uint32_t	vdc_instance_count = 0;
    260 
    261 /* Tunable to log all SCSI errors */
    262 static boolean_t vdc_scsi_log_error = B_FALSE;
    263 
    264 /* Soft state pointer */
    265 static void	*vdc_state;
    266 
    267 /*
    268  * Controlling the verbosity of the error/debug messages
    269  *
    270  * vdc_msglevel - controls level of messages
    271  * vdc_matchinst - 64-bit variable where each bit corresponds
    272  *                 to the vdc instance the vdc_msglevel applies.
    273  */
    274 int		vdc_msglevel = 0x0;
    275 uint64_t	vdc_matchinst = 0ull;
    276 
    277 /*
    278  * Supported vDisk protocol version pairs.
    279  *
    280  * The first array entry is the latest and preferred version.
    281  */
    282 static const vio_ver_t	vdc_version[] = {{1, 1}};
    283 
    284 static struct cb_ops vdc_cb_ops = {
    285 	vdc_open,	/* cb_open */
    286 	vdc_close,	/* cb_close */
    287 	vdc_strategy,	/* cb_strategy */
    288 	vdc_print,	/* cb_print */
    289 	vdc_dump,	/* cb_dump */
    290 	vdc_read,	/* cb_read */
    291 	vdc_write,	/* cb_write */
    292 	vdc_ioctl,	/* cb_ioctl */
    293 	nodev,		/* cb_devmap */
    294 	nodev,		/* cb_mmap */
    295 	nodev,		/* cb_segmap */
    296 	nochpoll,	/* cb_chpoll */
    297 	vdc_prop_op,	/* cb_prop_op */
    298 	NULL,		/* cb_str */
    299 	D_MP | D_64BIT,	/* cb_flag */
    300 	CB_REV,		/* cb_rev */
    301 	vdc_aread,	/* cb_aread */
    302 	vdc_awrite	/* cb_awrite */
    303 };
    304 
    305 static struct dev_ops vdc_ops = {
    306 	DEVO_REV,	/* devo_rev */
    307 	0,		/* devo_refcnt */
    308 	vdc_getinfo,	/* devo_getinfo */
    309 	nulldev,	/* devo_identify */
    310 	nulldev,	/* devo_probe */
    311 	vdc_attach,	/* devo_attach */
    312 	vdc_detach,	/* devo_detach */
    313 	nodev,		/* devo_reset */
    314 	&vdc_cb_ops,	/* devo_cb_ops */
    315 	NULL,		/* devo_bus_ops */
    316 	nulldev,	/* devo_power */
    317 	ddi_quiesce_not_needed,	/* devo_quiesce */
    318 };
    319 
    320 static struct modldrv modldrv = {
    321 	&mod_driverops,
    322 	"virtual disk client",
    323 	&vdc_ops,
    324 };
    325 
    326 static struct modlinkage modlinkage = {
    327 	MODREV_1,
    328 	&modldrv,
    329 	NULL
    330 };
    331 
    332 /* -------------------------------------------------------------------------- */
    333 
    334 /*
    335  * Device Driver housekeeping and setup
    336  */
    337 
    338 int
    339 _init(void)
    340 {
    341 	int	status;
    342 
    343 	if ((status = ddi_soft_state_init(&vdc_state, sizeof (vdc_t), 1)) != 0)
    344 		return (status);
    345 	if ((status = mod_install(&modlinkage)) != 0)
    346 		ddi_soft_state_fini(&vdc_state);
    347 	return (status);
    348 }
    349 
    350 int
    351 _info(struct modinfo *modinfop)
    352 {
    353 	return (mod_info(&modlinkage, modinfop));
    354 }
    355 
    356 int
    357 _fini(void)
    358 {
    359 	int	status;
    360 
    361 	if ((status = mod_remove(&modlinkage)) != 0)
    362 		return (status);
    363 	ddi_soft_state_fini(&vdc_state);
    364 	return (0);
    365 }
    366 
    367 static int
    368 vdc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd,  void *arg, void **resultp)
    369 {
    370 	_NOTE(ARGUNUSED(dip))
    371 
    372 	int	instance = VDCUNIT((dev_t)arg);
    373 	vdc_t	*vdc = NULL;
    374 
    375 	switch (cmd) {
    376 	case DDI_INFO_DEVT2DEVINFO:
    377 		if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
    378 			*resultp = NULL;
    379 			return (DDI_FAILURE);
    380 		}
    381 		*resultp = vdc->dip;
    382 		return (DDI_SUCCESS);
    383 	case DDI_INFO_DEVT2INSTANCE:
    384 		*resultp = (void *)(uintptr_t)instance;
    385 		return (DDI_SUCCESS);
    386 	default:
    387 		*resultp = NULL;
    388 		return (DDI_FAILURE);
    389 	}
    390 }
    391 
    392 static int
    393 vdc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
    394 {
    395 	kt_did_t failfast_tid, ownership_tid;
    396 	int	instance;
    397 	int	rv;
    398 	vdc_server_t *srvr;
    399 	vdc_t	*vdc = NULL;
    400 
    401 	switch (cmd) {
    402 	case DDI_DETACH:
    403 		/* the real work happens below */
    404 		break;
    405 	case DDI_SUSPEND:
    406 		/* nothing to do for this non-device */
    407 		return (DDI_SUCCESS);
    408 	default:
    409 		return (DDI_FAILURE);
    410 	}
    411 
    412 	ASSERT(cmd == DDI_DETACH);
    413 	instance = ddi_get_instance(dip);
    414 	DMSGX(1, "[%d] Entered\n", instance);
    415 
    416 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
    417 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
    418 		return (DDI_FAILURE);
    419 	}
    420 
    421 	/*
    422 	 * This function is called when vdc is detached or if it has failed to
    423 	 * attach. In that case, the attach may have fail before the vdisk type
    424 	 * has been set so we can't call vdc_is_opened(). However as the attach
    425 	 * has failed, we know that the vdisk is not opened and we can safely
    426 	 * detach.
    427 	 */
    428 	if (vdc->vdisk_type != VD_DISK_TYPE_UNK && vdc_is_opened(vdc)) {
    429 		DMSG(vdc, 0, "[%d] Cannot detach: device is open", instance);
    430 		return (DDI_FAILURE);
    431 	}
    432 
    433 	if (vdc->dkio_flush_pending) {
    434 		DMSG(vdc, 0,
    435 		    "[%d] Cannot detach: %d outstanding DKIO flushes\n",
    436 		    instance, vdc->dkio_flush_pending);
    437 		return (DDI_FAILURE);
    438 	}
    439 
    440 	if (vdc->validate_pending) {
    441 		DMSG(vdc, 0,
    442 		    "[%d] Cannot detach: %d outstanding validate request\n",
    443 		    instance, vdc->validate_pending);
    444 		return (DDI_FAILURE);
    445 	}
    446 
    447 	DMSG(vdc, 0, "[%d] proceeding...\n", instance);
    448 
    449 	/* If we took ownership, release ownership */
    450 	mutex_enter(&vdc->ownership_lock);
    451 	if (vdc->ownership & VDC_OWNERSHIP_GRANTED) {
    452 		rv = vdc_access_set(vdc, VD_ACCESS_SET_CLEAR, FKIOCTL);
    453 		if (rv == 0) {
    454 			vdc_ownership_update(vdc, VDC_OWNERSHIP_NONE);
    455 		}
    456 	}
    457 	mutex_exit(&vdc->ownership_lock);
    458 
    459 	/* mark instance as detaching */
    460 	vdc->lifecycle	= VDC_LC_DETACHING;
    461 
    462 	/*
    463 	 * Try and disable callbacks to prevent another handshake. We have to
    464 	 * disable callbacks for all servers.
    465 	 */
    466 	for (srvr = vdc->server_list; srvr != NULL; srvr = srvr->next) {
    467 		rv = ldc_set_cb_mode(srvr->ldc_handle, LDC_CB_DISABLE);
    468 		DMSG(vdc, 0, "callback disabled (ldc=%lu, rv=%d)\n",
    469 		    srvr->ldc_id, rv);
    470 	}
    471 
    472 	if (vdc->initialized & VDC_THREAD) {
    473 		mutex_enter(&vdc->read_lock);
    474 		if ((vdc->read_state == VDC_READ_WAITING) ||
    475 		    (vdc->read_state == VDC_READ_RESET)) {
    476 			vdc->read_state = VDC_READ_RESET;
    477 			cv_signal(&vdc->read_cv);
    478 		}
    479 
    480 		mutex_exit(&vdc->read_lock);
    481 
    482 		/* wake up any thread waiting for connection to come online */
    483 		mutex_enter(&vdc->lock);
    484 		if (vdc->state == VDC_STATE_INIT_WAITING) {
    485 			DMSG(vdc, 0,
    486 			    "[%d] write reset - move to resetting state...\n",
    487 			    instance);
    488 			vdc->state = VDC_STATE_RESETTING;
    489 			cv_signal(&vdc->initwait_cv);
    490 		}
    491 		mutex_exit(&vdc->lock);
    492 
    493 		/* now wait until state transitions to VDC_STATE_DETACH */
    494 		thread_join(vdc->msg_proc_thr->t_did);
    495 		ASSERT(vdc->state == VDC_STATE_DETACH);
    496 		DMSG(vdc, 0, "[%d] Reset thread exit and join ..\n",
    497 		    vdc->instance);
    498 	}
    499 
    500 	mutex_enter(&vdc->lock);
    501 
    502 	if (vdc->initialized & VDC_DRING)
    503 		vdc_destroy_descriptor_ring(vdc);
    504 
    505 	vdc_fini_ports(vdc);
    506 
    507 	if (vdc->failfast_thread) {
    508 		failfast_tid = vdc->failfast_thread->t_did;
    509 		vdc->failfast_interval = 0;
    510 		cv_signal(&vdc->failfast_cv);
    511 	} else {
    512 		failfast_tid = 0;
    513 	}
    514 
    515 	if (vdc->ownership & VDC_OWNERSHIP_WANTED) {
    516 		ownership_tid = vdc->ownership_thread->t_did;
    517 		vdc->ownership = VDC_OWNERSHIP_NONE;
    518 		cv_signal(&vdc->ownership_cv);
    519 	} else {
    520 		ownership_tid = 0;
    521 	}
    522 
    523 	mutex_exit(&vdc->lock);
    524 
    525 	if (failfast_tid != 0)
    526 		thread_join(failfast_tid);
    527 
    528 	if (ownership_tid != 0)
    529 		thread_join(ownership_tid);
    530 
    531 	if (vdc->initialized & VDC_MINOR)
    532 		ddi_remove_minor_node(dip, NULL);
    533 
    534 	if (vdc->io_stats) {
    535 		kstat_delete(vdc->io_stats);
    536 		vdc->io_stats = NULL;
    537 	}
    538 
    539 	if (vdc->err_stats) {
    540 		kstat_delete(vdc->err_stats);
    541 		vdc->err_stats = NULL;
    542 	}
    543 
    544 	if (vdc->initialized & VDC_LOCKS) {
    545 		mutex_destroy(&vdc->lock);
    546 		mutex_destroy(&vdc->read_lock);
    547 		mutex_destroy(&vdc->ownership_lock);
    548 		cv_destroy(&vdc->initwait_cv);
    549 		cv_destroy(&vdc->dring_free_cv);
    550 		cv_destroy(&vdc->membind_cv);
    551 		cv_destroy(&vdc->sync_pending_cv);
    552 		cv_destroy(&vdc->sync_blocked_cv);
    553 		cv_destroy(&vdc->read_cv);
    554 		cv_destroy(&vdc->running_cv);
    555 		cv_destroy(&vdc->ownership_cv);
    556 		cv_destroy(&vdc->failfast_cv);
    557 		cv_destroy(&vdc->failfast_io_cv);
    558 	}
    559 
    560 	if (vdc->minfo)
    561 		kmem_free(vdc->minfo, sizeof (struct dk_minfo));
    562 
    563 	if (vdc->cinfo)
    564 		kmem_free(vdc->cinfo, sizeof (struct dk_cinfo));
    565 
    566 	if (vdc->vtoc)
    567 		kmem_free(vdc->vtoc, sizeof (struct extvtoc));
    568 
    569 	if (vdc->geom)
    570 		kmem_free(vdc->geom, sizeof (struct dk_geom));
    571 
    572 	if (vdc->devid) {
    573 		ddi_devid_unregister(dip);
    574 		ddi_devid_free(vdc->devid);
    575 	}
    576 
    577 	if (vdc->initialized & VDC_SOFT_STATE)
    578 		ddi_soft_state_free(vdc_state, instance);
    579 
    580 	DMSG(vdc, 0, "[%d] End %p\n", instance, (void *)vdc);
    581 
    582 	return (DDI_SUCCESS);
    583 }
    584 
    585 
    586 static int
    587 vdc_do_attach(dev_info_t *dip)
    588 {
    589 	int		instance;
    590 	vdc_t		*vdc = NULL;
    591 	int		status;
    592 	md_t		*mdp;
    593 	mde_cookie_t	vd_node;
    594 
    595 	ASSERT(dip != NULL);
    596 
    597 	instance = ddi_get_instance(dip);
    598 	if (ddi_soft_state_zalloc(vdc_state, instance) != DDI_SUCCESS) {
    599 		cmn_err(CE_NOTE, "[%d] Couldn't alloc state structure",
    600 		    instance);
    601 		return (DDI_FAILURE);
    602 	}
    603 
    604 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
    605 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
    606 		return (DDI_FAILURE);
    607 	}
    608 
    609 	/*
    610 	 * We assign the value to initialized in this case to zero out the
    611 	 * variable and then set bits in it to indicate what has been done
    612 	 */
    613 	vdc->initialized = VDC_SOFT_STATE;
    614 
    615 	vdc_hz_min_ldc_delay = drv_usectohz(vdc_min_timeout_ldc);
    616 	vdc_hz_max_ldc_delay = drv_usectohz(vdc_max_timeout_ldc);
    617 
    618 	vdc->dip	= dip;
    619 	vdc->instance	= instance;
    620 	vdc->vdisk_type	= VD_DISK_TYPE_UNK;
    621 	vdc->vdisk_label = VD_DISK_LABEL_UNK;
    622 	vdc->state	= VDC_STATE_INIT;
    623 	vdc->lifecycle	= VDC_LC_ATTACHING;
    624 	vdc->session_id = 0;
    625 	vdc->vdisk_bsize = DEV_BSIZE;
    626 	vdc->vio_bmask = 0;
    627 	vdc->vio_bshift = 0;
    628 	vdc->max_xfer_sz = maxphys / vdc->vdisk_bsize;
    629 
    630 	/*
    631 	 * We assume, for now, that the vDisk server will export 'read'
    632 	 * operations to us at a minimum (this is needed because of checks
    633 	 * in vdc for supported operations early in the handshake process).
    634 	 * The vDisk server will return ENOTSUP if this is not the case.
    635 	 * The value will be overwritten during the attribute exchange with
    636 	 * the bitmask of operations exported by server.
    637 	 */
    638 	vdc->operations = VD_OP_MASK_READ;
    639 
    640 	vdc->vtoc = NULL;
    641 	vdc->geom = NULL;
    642 	vdc->cinfo = NULL;
    643 	vdc->minfo = NULL;
    644 
    645 	mutex_init(&vdc->lock, NULL, MUTEX_DRIVER, NULL);
    646 	cv_init(&vdc->initwait_cv, NULL, CV_DRIVER, NULL);
    647 	cv_init(&vdc->dring_free_cv, NULL, CV_DRIVER, NULL);
    648 	cv_init(&vdc->membind_cv, NULL, CV_DRIVER, NULL);
    649 	cv_init(&vdc->running_cv, NULL, CV_DRIVER, NULL);
    650 
    651 	vdc->threads_pending = 0;
    652 	vdc->sync_op_pending = B_FALSE;
    653 	vdc->sync_op_blocked = B_FALSE;
    654 	cv_init(&vdc->sync_pending_cv, NULL, CV_DRIVER, NULL);
    655 	cv_init(&vdc->sync_blocked_cv, NULL, CV_DRIVER, NULL);
    656 
    657 	mutex_init(&vdc->ownership_lock, NULL, MUTEX_DRIVER, NULL);
    658 	cv_init(&vdc->ownership_cv, NULL, CV_DRIVER, NULL);
    659 	cv_init(&vdc->failfast_cv, NULL, CV_DRIVER, NULL);
    660 	cv_init(&vdc->failfast_io_cv, NULL, CV_DRIVER, NULL);
    661 
    662 	/* init blocking msg read functionality */
    663 	mutex_init(&vdc->read_lock, NULL, MUTEX_DRIVER, NULL);
    664 	cv_init(&vdc->read_cv, NULL, CV_DRIVER, NULL);
    665 	vdc->read_state = VDC_READ_IDLE;
    666 
    667 	vdc->initialized |= VDC_LOCKS;
    668 
    669 	/* get device and port MD node for this disk instance */
    670 	if (vdc_get_md_node(dip, &mdp, &vd_node) != 0) {
    671 		cmn_err(CE_NOTE, "[%d] Could not get machine description node",
    672 		    instance);
    673 		return (DDI_FAILURE);
    674 	}
    675 
    676 	if (vdc_init_ports(vdc, mdp, vd_node) != 0) {
    677 		cmn_err(CE_NOTE, "[%d] Error initialising ports", instance);
    678 		return (DDI_FAILURE);
    679 	}
    680 
    681 	(void) md_fini_handle(mdp);
    682 
    683 	/* Create the kstats for saving the I/O statistics used by iostat(1M) */
    684 	vdc_create_io_kstats(vdc);
    685 	vdc_create_err_kstats(vdc);
    686 
    687 	/* Initialize remaining structures before starting the msg thread */
    688 	vdc->vdisk_label = VD_DISK_LABEL_UNK;
    689 	vdc->vtoc = kmem_zalloc(sizeof (struct extvtoc), KM_SLEEP);
    690 	vdc->geom = kmem_zalloc(sizeof (struct dk_geom), KM_SLEEP);
    691 	vdc->minfo = kmem_zalloc(sizeof (struct dk_minfo), KM_SLEEP);
    692 
    693 	/* initialize the thread responsible for managing state with server */
    694 	vdc->msg_proc_thr = thread_create(NULL, 0, vdc_process_msg_thread,
    695 	    vdc, 0, &p0, TS_RUN, minclsyspri);
    696 	if (vdc->msg_proc_thr == NULL) {
    697 		cmn_err(CE_NOTE, "[%d] Failed to create msg processing thread",
    698 		    instance);
    699 		return (DDI_FAILURE);
    700 	}
    701 
    702 	vdc->initialized |= VDC_THREAD;
    703 
    704 	atomic_inc_32(&vdc_instance_count);
    705 
    706 	/*
    707 	 * Check the disk label. This will send requests and do the handshake.
    708 	 * We don't really care about the disk label now. What we really need is
    709 	 * the handshake do be done so that we know the type of the disk (slice
    710 	 * or full disk) and the appropriate device nodes can be created.
    711 	 */
    712 
    713 	mutex_enter(&vdc->lock);
    714 	(void) vdc_validate_geometry(vdc);
    715 	mutex_exit(&vdc->lock);
    716 
    717 	/*
    718 	 * Now that we have the device info we can create the device nodes
    719 	 */
    720 	status = vdc_create_device_nodes(vdc);
    721 	if (status) {
    722 		DMSG(vdc, 0, "[%d] Failed to create device nodes",
    723 		    instance);
    724 		goto return_status;
    725 	}
    726 
    727 	/*
    728 	 * Setup devid
    729 	 */
    730 	if (vdc_setup_devid(vdc)) {
    731 		DMSG(vdc, 0, "[%d] No device id available\n", instance);
    732 	}
    733 
    734 	/*
    735 	 * Fill in the fields of the error statistics kstat that were not
    736 	 * available when creating the kstat
    737 	 */
    738 	vdc_set_err_kstats(vdc);
    739 
    740 	ddi_report_dev(dip);
    741 	vdc->lifecycle	= VDC_LC_ONLINE;
    742 	DMSG(vdc, 0, "[%d] Attach tasks successful\n", instance);
    743 
    744 return_status:
    745 	DMSG(vdc, 0, "[%d] Attach completed\n", instance);
    746 	return (status);
    747 }
    748 
    749 static int
    750 vdc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
    751 {
    752 	int	status;
    753 
    754 	switch (cmd) {
    755 	case DDI_ATTACH:
    756 		if ((status = vdc_do_attach(dip)) != 0)
    757 			(void) vdc_detach(dip, DDI_DETACH);
    758 		return (status);
    759 	case DDI_RESUME:
    760 		/* nothing to do for this non-device */
    761 		return (DDI_SUCCESS);
    762 	default:
    763 		return (DDI_FAILURE);
    764 	}
    765 }
    766 
    767 static int
    768 vdc_do_ldc_init(vdc_t *vdc, vdc_server_t *srvr)
    769 {
    770 	int			status = 0;
    771 	ldc_status_t		ldc_state;
    772 	ldc_attr_t		ldc_attr;
    773 
    774 	ASSERT(vdc != NULL);
    775 	ASSERT(srvr != NULL);
    776 
    777 	ldc_attr.devclass = LDC_DEV_BLK;
    778 	ldc_attr.instance = vdc->instance;
    779 	ldc_attr.mode = LDC_MODE_UNRELIABLE;	/* unreliable transport */
    780 	ldc_attr.mtu = VD_LDC_MTU;
    781 
    782 	if ((srvr->state & VDC_LDC_INIT) == 0) {
    783 		status = ldc_init(srvr->ldc_id, &ldc_attr,
    784 		    &srvr->ldc_handle);
    785 		if (status != 0) {
    786 			DMSG(vdc, 0, "[%d] ldc_init(chan %ld) returned %d",
    787 			    vdc->instance, srvr->ldc_id, status);
    788 			return (status);
    789 		}
    790 		srvr->state |= VDC_LDC_INIT;
    791 	}
    792 	status = ldc_status(srvr->ldc_handle, &ldc_state);
    793 	if (status != 0) {
    794 		DMSG(vdc, 0, "[%d] Cannot discover LDC status [err=%d]",
    795 		    vdc->instance, status);
    796 		goto init_exit;
    797 	}
    798 	srvr->ldc_state = ldc_state;
    799 
    800 	if ((srvr->state & VDC_LDC_CB) == 0) {
    801 		status = ldc_reg_callback(srvr->ldc_handle, vdc_handle_cb,
    802 		    (caddr_t)srvr);
    803 		if (status != 0) {
    804 			DMSG(vdc, 0, "[%d] LDC callback reg. failed (%d)",
    805 			    vdc->instance, status);
    806 			goto init_exit;
    807 		}
    808 		srvr->state |= VDC_LDC_CB;
    809 	}
    810 
    811 	/*
    812 	 * At this stage we have initialised LDC, we will now try and open
    813 	 * the connection.
    814 	 */
    815 	if (srvr->ldc_state == LDC_INIT) {
    816 		status = ldc_open(srvr->ldc_handle);
    817 		if (status != 0) {
    818 			DMSG(vdc, 0, "[%d] ldc_open(chan %ld) returned %d",
    819 			    vdc->instance, srvr->ldc_id, status);
    820 			goto init_exit;
    821 		}
    822 		srvr->state |= VDC_LDC_OPEN;
    823 	}
    824 
    825 init_exit:
    826 	if (status) {
    827 		vdc_terminate_ldc(vdc, srvr);
    828 	}
    829 
    830 	return (status);
    831 }
    832 
    833 static int
    834 vdc_start_ldc_connection(vdc_t *vdc)
    835 {
    836 	int		status = 0;
    837 
    838 	ASSERT(vdc != NULL);
    839 
    840 	ASSERT(MUTEX_HELD(&vdc->lock));
    841 
    842 	status = vdc_do_ldc_up(vdc);
    843 
    844 	DMSG(vdc, 0, "[%d] Finished bringing up LDC\n", vdc->instance);
    845 
    846 	return (status);
    847 }
    848 
    849 static int
    850 vdc_stop_ldc_connection(vdc_t *vdcp)
    851 {
    852 	int	status;
    853 
    854 	ASSERT(vdcp != NULL);
    855 
    856 	ASSERT(MUTEX_HELD(&vdcp->lock));
    857 
    858 	DMSG(vdcp, 0, ": Resetting connection to vDisk server : state %d\n",
    859 	    vdcp->state);
    860 
    861 	status = ldc_down(vdcp->curr_server->ldc_handle);
    862 	DMSG(vdcp, 0, "ldc_down() = %d\n", status);
    863 
    864 	vdcp->initialized &= ~VDC_HANDSHAKE;
    865 	DMSG(vdcp, 0, "initialized=%x\n", vdcp->initialized);
    866 
    867 	return (status);
    868 }
    869 
    870 static void
    871 vdc_create_io_kstats(vdc_t *vdc)
    872 {
    873 	if (vdc->io_stats != NULL) {
    874 		DMSG(vdc, 0, "[%d] I/O kstat already exists\n", vdc->instance);
    875 		return;
    876 	}
    877 
    878 	vdc->io_stats = kstat_create(VDC_DRIVER_NAME, vdc->instance, NULL,
    879 	    "disk", KSTAT_TYPE_IO, 1, KSTAT_FLAG_PERSISTENT);
    880 	if (vdc->io_stats != NULL) {
    881 		vdc->io_stats->ks_lock = &vdc->lock;
    882 		kstat_install(vdc->io_stats);
    883 	} else {
    884 		cmn_err(CE_NOTE, "[%d] Failed to create kstat: I/O statistics"
    885 		    " will not be gathered", vdc->instance);
    886 	}
    887 }
    888 
    889 static void
    890 vdc_create_err_kstats(vdc_t *vdc)
    891 {
    892 	vd_err_stats_t	*stp;
    893 	char	kstatmodule_err[KSTAT_STRLEN];
    894 	char	kstatname[KSTAT_STRLEN];
    895 	int	ndata = (sizeof (vd_err_stats_t) / sizeof (kstat_named_t));
    896 	int	instance = vdc->instance;
    897 
    898 	if (vdc->err_stats != NULL) {
    899 		DMSG(vdc, 0, "[%d] ERR kstat already exists\n", vdc->instance);
    900 		return;
    901 	}
    902 
    903 	(void) snprintf(kstatmodule_err, sizeof (kstatmodule_err),
    904 	    "%serr", VDC_DRIVER_NAME);
    905 	(void) snprintf(kstatname, sizeof (kstatname),
    906 	    "%s%d,err", VDC_DRIVER_NAME, instance);
    907 
    908 	vdc->err_stats = kstat_create(kstatmodule_err, instance, kstatname,
    909 	    "device_error", KSTAT_TYPE_NAMED, ndata, KSTAT_FLAG_PERSISTENT);
    910 
    911 	if (vdc->err_stats == NULL) {
    912 		cmn_err(CE_NOTE, "[%d] Failed to create kstat: Error statistics"
    913 		    " will not be gathered", instance);
    914 		return;
    915 	}
    916 
    917 	stp = (vd_err_stats_t *)vdc->err_stats->ks_data;
    918 	kstat_named_init(&stp->vd_softerrs,	"Soft Errors",
    919 	    KSTAT_DATA_UINT32);
    920 	kstat_named_init(&stp->vd_transerrs,	"Transport Errors",
    921 	    KSTAT_DATA_UINT32);
    922 	kstat_named_init(&stp->vd_protoerrs,	"Protocol Errors",
    923 	    KSTAT_DATA_UINT32);
    924 	kstat_named_init(&stp->vd_vid,		"Vendor",
    925 	    KSTAT_DATA_CHAR);
    926 	kstat_named_init(&stp->vd_pid,		"Product",
    927 	    KSTAT_DATA_CHAR);
    928 	kstat_named_init(&stp->vd_capacity,	"Size",
    929 	    KSTAT_DATA_ULONGLONG);
    930 
    931 	vdc->err_stats->ks_update  = nulldev;
    932 
    933 	kstat_install(vdc->err_stats);
    934 }
    935 
    936 static void
    937 vdc_set_err_kstats(vdc_t *vdc)
    938 {
    939 	vd_err_stats_t  *stp;
    940 
    941 	if (vdc->err_stats == NULL)
    942 		return;
    943 
    944 	mutex_enter(&vdc->lock);
    945 
    946 	stp = (vd_err_stats_t *)vdc->err_stats->ks_data;
    947 	ASSERT(stp != NULL);
    948 
    949 	stp->vd_capacity.value.ui64 = vdc->vdisk_size * vdc->vdisk_bsize;
    950 	(void) strcpy(stp->vd_vid.value.c, "SUN");
    951 	(void) strcpy(stp->vd_pid.value.c, "VDSK");
    952 
    953 	mutex_exit(&vdc->lock);
    954 }
    955 
    956 static int
    957 vdc_create_device_nodes_efi(vdc_t *vdc)
    958 {
    959 	ddi_remove_minor_node(vdc->dip, "h");
    960 	ddi_remove_minor_node(vdc->dip, "h,raw");
    961 
    962 	if (ddi_create_minor_node(vdc->dip, "wd", S_IFBLK,
    963 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
    964 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
    965 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'wd'",
    966 		    vdc->instance);
    967 		return (EIO);
    968 	}
    969 
    970 	/* if any device node is created we set this flag */
    971 	vdc->initialized |= VDC_MINOR;
    972 
    973 	if (ddi_create_minor_node(vdc->dip, "wd,raw", S_IFCHR,
    974 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
    975 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
    976 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'wd,raw'",
    977 		    vdc->instance);
    978 		return (EIO);
    979 	}
    980 
    981 	return (0);
    982 }
    983 
    984 static int
    985 vdc_create_device_nodes_vtoc(vdc_t *vdc)
    986 {
    987 	ddi_remove_minor_node(vdc->dip, "wd");
    988 	ddi_remove_minor_node(vdc->dip, "wd,raw");
    989 
    990 	if (ddi_create_minor_node(vdc->dip, "h", S_IFBLK,
    991 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
    992 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
    993 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'h'",
    994 		    vdc->instance);
    995 		return (EIO);
    996 	}
    997 
    998 	/* if any device node is created we set this flag */
    999 	vdc->initialized |= VDC_MINOR;
   1000 
   1001 	if (ddi_create_minor_node(vdc->dip, "h,raw", S_IFCHR,
   1002 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
   1003 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
   1004 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'h,raw'",
   1005 		    vdc->instance);
   1006 		return (EIO);
   1007 	}
   1008 
   1009 	return (0);
   1010 }
   1011 
   1012 /*
   1013  * Function:
   1014  *	vdc_create_device_nodes
   1015  *
   1016  * Description:
   1017  *	This function creates the block and character device nodes under
   1018  *	/devices. It is called as part of the attach(9E) of the instance
   1019  *	during the handshake with vds after vds has sent the attributes
   1020  *	to vdc.
   1021  *
   1022  *	If the device is of type VD_DISK_TYPE_SLICE then the minor node
   1023  *	of 2 is used in keeping with the Solaris convention that slice 2
   1024  *	refers to a whole disk. Slices start at 'a'
   1025  *
   1026  * Parameters:
   1027  *	vdc 		- soft state pointer
   1028  *
   1029  * Return Values
   1030  *	0		- Success
   1031  *	EIO		- Failed to create node
   1032  *	EINVAL		- Unknown type of disk exported
   1033  */
   1034 static int
   1035 vdc_create_device_nodes(vdc_t *vdc)
   1036 {
   1037 	char		name[sizeof ("s,raw")];
   1038 	dev_info_t	*dip = NULL;
   1039 	int		instance, status;
   1040 	int		num_slices = 1;
   1041 	int		i;
   1042 
   1043 	ASSERT(vdc != NULL);
   1044 
   1045 	instance = vdc->instance;
   1046 	dip = vdc->dip;
   1047 
   1048 	switch (vdc->vdisk_type) {
   1049 	case VD_DISK_TYPE_DISK:
   1050 		num_slices = V_NUMPAR;
   1051 		break;
   1052 	case VD_DISK_TYPE_SLICE:
   1053 		num_slices = 1;
   1054 		break;
   1055 	case VD_DISK_TYPE_UNK:
   1056 	default:
   1057 		return (EINVAL);
   1058 	}
   1059 
   1060 	/*
   1061 	 * Minor nodes are different for EFI disks: EFI disks do not have
   1062 	 * a minor node 'g' for the minor number corresponding to slice
   1063 	 * VD_EFI_WD_SLICE (slice 7) instead they have a minor node 'wd'
   1064 	 * representing the whole disk.
   1065 	 */
   1066 	for (i = 0; i < num_slices; i++) {
   1067 
   1068 		if (i == VD_EFI_WD_SLICE) {
   1069 			if (vdc->vdisk_label == VD_DISK_LABEL_EFI)
   1070 				status = vdc_create_device_nodes_efi(vdc);
   1071 			else
   1072 				status = vdc_create_device_nodes_vtoc(vdc);
   1073 			if (status != 0)
   1074 				return (status);
   1075 			continue;
   1076 		}
   1077 
   1078 		(void) snprintf(name, sizeof (name), "%c", 'a' + i);
   1079 		if (ddi_create_minor_node(dip, name, S_IFBLK,
   1080 		    VD_MAKE_DEV(instance, i), DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
   1081 			cmn_err(CE_NOTE, "[%d] Couldn't add block node '%s'",
   1082 			    instance, name);
   1083 			return (EIO);
   1084 		}
   1085 
   1086 		/* if any device node is created we set this flag */
   1087 		vdc->initialized |= VDC_MINOR;
   1088 
   1089 		(void) snprintf(name, sizeof (name), "%c%s", 'a' + i, ",raw");
   1090 
   1091 		if (ddi_create_minor_node(dip, name, S_IFCHR,
   1092 		    VD_MAKE_DEV(instance, i), DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
   1093 			cmn_err(CE_NOTE, "[%d] Couldn't add raw node '%s'",
   1094 			    instance, name);
   1095 			return (EIO);
   1096 		}
   1097 	}
   1098 
   1099 	return (0);
   1100 }
   1101 
   1102 /*
   1103  * Driver prop_op(9e) entry point function. Return the number of blocks for
   1104  * the partition in question or forward the request to the property facilities.
   1105  */
   1106 static int
   1107 vdc_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op, int mod_flags,
   1108     char *name, caddr_t valuep, int *lengthp)
   1109 {
   1110 	int instance = ddi_get_instance(dip);
   1111 	vdc_t *vdc;
   1112 	uint64_t nblocks;
   1113 	uint_t blksize;
   1114 
   1115 	vdc = ddi_get_soft_state(vdc_state, instance);
   1116 
   1117 	if (dev == DDI_DEV_T_ANY || vdc == NULL) {
   1118 		return (ddi_prop_op(dev, dip, prop_op, mod_flags,
   1119 		    name, valuep, lengthp));
   1120 	}
   1121 
   1122 	mutex_enter(&vdc->lock);
   1123 	(void) vdc_validate_geometry(vdc);
   1124 	if (vdc->vdisk_label == VD_DISK_LABEL_UNK) {
   1125 		mutex_exit(&vdc->lock);
   1126 		return (ddi_prop_op(dev, dip, prop_op, mod_flags,
   1127 		    name, valuep, lengthp));
   1128 	}
   1129 	nblocks = vdc->slice[VDCPART(dev)].nblocks;
   1130 	blksize = vdc->vdisk_bsize;
   1131 	mutex_exit(&vdc->lock);
   1132 
   1133 	return (ddi_prop_op_nblocks_blksize(dev, dip, prop_op, mod_flags,
   1134 	    name, valuep, lengthp, nblocks, blksize));
   1135 }
   1136 
   1137 /*
   1138  * Function:
   1139  *	vdc_is_opened
   1140  *
   1141  * Description:
   1142  *	This function checks if any slice of a given virtual disk is
   1143  *	currently opened.
   1144  *
   1145  * Parameters:
   1146  *	vdc 		- soft state pointer
   1147  *
   1148  * Return Values
   1149  *	B_TRUE		- at least one slice is opened.
   1150  *	B_FALSE		- no slice is opened.
   1151  */
   1152 static boolean_t
   1153 vdc_is_opened(vdc_t *vdc)
   1154 {
   1155 	int i, nslices;
   1156 
   1157 	switch (vdc->vdisk_type) {
   1158 	case VD_DISK_TYPE_DISK:
   1159 		nslices = V_NUMPAR;
   1160 		break;
   1161 	case VD_DISK_TYPE_SLICE:
   1162 		nslices = 1;
   1163 		break;
   1164 	case VD_DISK_TYPE_UNK:
   1165 	default:
   1166 		ASSERT(0);
   1167 	}
   1168 
   1169 	/* check if there's any layered open */
   1170 	for (i = 0; i < nslices; i++) {
   1171 		if (vdc->open_lyr[i] > 0)
   1172 			return (B_TRUE);
   1173 	}
   1174 
   1175 	/* check if there is any other kind of open */
   1176 	for (i = 0; i < OTYPCNT; i++) {
   1177 		if (vdc->open[i] != 0)
   1178 			return (B_TRUE);
   1179 	}
   1180 
   1181 	return (B_FALSE);
   1182 }
   1183 
   1184 static int
   1185 vdc_mark_opened(vdc_t *vdc, int slice, int flag, int otyp)
   1186 {
   1187 	uint8_t slicemask;
   1188 	int i;
   1189 
   1190 	ASSERT(otyp < OTYPCNT);
   1191 	ASSERT(slice < V_NUMPAR);
   1192 	ASSERT(MUTEX_HELD(&vdc->lock));
   1193 
   1194 	slicemask = 1 << slice;
   1195 
   1196 	/* check if slice is already exclusively opened */
   1197 	if (vdc->open_excl & slicemask)
   1198 		return (EBUSY);
   1199 
   1200 	/* if open exclusive, check if slice is already opened */
   1201 	if (flag & FEXCL) {
   1202 		if (vdc->open_lyr[slice] > 0)
   1203 			return (EBUSY);
   1204 		for (i = 0; i < OTYPCNT; i++) {
   1205 			if (vdc->open[i] & slicemask)
   1206 				return (EBUSY);
   1207 		}
   1208 		vdc->open_excl |= slicemask;
   1209 	}
   1210 
   1211 	/* mark slice as opened */
   1212 	if (otyp == OTYP_LYR) {
   1213 		vdc->open_lyr[slice]++;
   1214 	} else {
   1215 		vdc->open[otyp] |= slicemask;
   1216 	}
   1217 
   1218 	return (0);
   1219 }
   1220 
   1221 static void
   1222 vdc_mark_closed(vdc_t *vdc, int slice, int flag, int otyp)
   1223 {
   1224 	uint8_t slicemask;
   1225 
   1226 	ASSERT(otyp < OTYPCNT);
   1227 	ASSERT(slice < V_NUMPAR);
   1228 	ASSERT(MUTEX_HELD(&vdc->lock));
   1229 
   1230 	slicemask = 1 << slice;
   1231 
   1232 	if (otyp == OTYP_LYR) {
   1233 		ASSERT(vdc->open_lyr[slice] > 0);
   1234 		vdc->open_lyr[slice]--;
   1235 	} else {
   1236 		vdc->open[otyp] &= ~slicemask;
   1237 	}
   1238 
   1239 	if (flag & FEXCL)
   1240 		vdc->open_excl &= ~slicemask;
   1241 }
   1242 
   1243 static int
   1244 vdc_open(dev_t *dev, int flag, int otyp, cred_t *cred)
   1245 {
   1246 	_NOTE(ARGUNUSED(cred))
   1247 
   1248 	int	instance, nodelay;
   1249 	int	slice, status = 0;
   1250 	vdc_t	*vdc;
   1251 
   1252 	ASSERT(dev != NULL);
   1253 	instance = VDCUNIT(*dev);
   1254 
   1255 	if (otyp >= OTYPCNT)
   1256 		return (EINVAL);
   1257 
   1258 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
   1259 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
   1260 		return (ENXIO);
   1261 	}
   1262 
   1263 	DMSG(vdc, 0, "minor = %d flag = %x, otyp = %x\n",
   1264 	    getminor(*dev), flag, otyp);
   1265 
   1266 	slice = VDCPART(*dev);
   1267 
   1268 	nodelay = flag & (FNDELAY | FNONBLOCK);
   1269 
   1270 	if ((flag & FWRITE) && (!nodelay) &&
   1271 	    !(VD_OP_SUPPORTED(vdc->operations, VD_OP_BWRITE))) {
   1272 		return (EROFS);
   1273 	}
   1274 
   1275 	mutex_enter(&vdc->lock);
   1276 
   1277 	status = vdc_mark_opened(vdc, slice, flag, otyp);
   1278 
   1279 	if (status != 0) {
   1280 		mutex_exit(&vdc->lock);
   1281 		return (status);
   1282 	}
   1283 
   1284 	if (nodelay) {
   1285 
   1286 		/* don't resubmit a validate request if there's already one */
   1287 		if (vdc->validate_pending > 0) {
   1288 			mutex_exit(&vdc->lock);
   1289 			return (0);
   1290 		}
   1291 
   1292 		/* call vdc_validate() asynchronously to avoid blocking */
   1293 		if (taskq_dispatch(system_taskq, vdc_validate_task,
   1294 		    (void *)vdc, TQ_NOSLEEP) == NULL) {
   1295 			vdc_mark_closed(vdc, slice, flag, otyp);
   1296 			mutex_exit(&vdc->lock);
   1297 			return (ENXIO);
   1298 		}
   1299 
   1300 		vdc->validate_pending++;
   1301 		mutex_exit(&vdc->lock);
   1302 		return (0);
   1303 	}
   1304 
   1305 	mutex_exit(&vdc->lock);
   1306 
   1307 	vdc_validate(vdc);
   1308 
   1309 	mutex_enter(&vdc->lock);
   1310 
   1311 	if (vdc->vdisk_label == VD_DISK_LABEL_UNK ||
   1312 	    vdc->slice[slice].nblocks == 0) {
   1313 		vdc_mark_closed(vdc, slice, flag, otyp);
   1314 		status = EIO;
   1315 	}
   1316 
   1317 	mutex_exit(&vdc->lock);
   1318 
   1319 	return (status);
   1320 }
   1321 
   1322 static int
   1323 vdc_close(dev_t dev, int flag, int otyp, cred_t *cred)
   1324 {
   1325 	_NOTE(ARGUNUSED(cred))
   1326 
   1327 	int	instance;
   1328 	int	slice;
   1329 	int	rv, rval;
   1330 	vdc_t	*vdc;
   1331 
   1332 	instance = VDCUNIT(dev);
   1333 
   1334 	if (otyp >= OTYPCNT)
   1335 		return (EINVAL);
   1336 
   1337 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
   1338 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
   1339 		return (ENXIO);
   1340 	}
   1341 
   1342 	DMSG(vdc, 0, "[%d] flag = %x, otyp = %x\n", instance, flag, otyp);
   1343 
   1344 	slice = VDCPART(dev);
   1345 
   1346 	/*
   1347 	 * Attempt to flush the W$ on a close operation. If this is
   1348 	 * not a supported IOCTL command or the backing device is read-only
   1349 	 * do not fail the close operation.
   1350 	 */
   1351 	rv = vd_process_ioctl(dev, DKIOCFLUSHWRITECACHE, NULL, FKIOCTL, &rval);
   1352 
   1353 	if (rv != 0 && rv != ENOTSUP && rv != ENOTTY && rv != EROFS) {
   1354 		DMSG(vdc, 0, "[%d] flush failed with error %d on close\n",
   1355 		    instance, rv);
   1356 		return (EIO);
   1357 	}
   1358 
   1359 	mutex_enter(&vdc->lock);
   1360 	vdc_mark_closed(vdc, slice, flag, otyp);
   1361 	mutex_exit(&vdc->lock);
   1362 
   1363 	return (0);
   1364 }
   1365 
   1366 static int
   1367 vdc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp, int *rvalp)
   1368 {
   1369 	_NOTE(ARGUNUSED(credp))
   1370 
   1371 	return (vd_process_ioctl(dev, cmd, (caddr_t)arg, mode, rvalp));
   1372 }
   1373 
   1374 static int
   1375 vdc_print(dev_t dev, char *str)
   1376 {
   1377 	cmn_err(CE_NOTE, "vdc%d:  %s", VDCUNIT(dev), str);
   1378 	return (0);
   1379 }
   1380 
   1381 static int
   1382 vdc_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblk)
   1383 {
   1384 	int	rv;
   1385 	size_t	nbytes = nblk * DEV_BSIZE;
   1386 	int	instance = VDCUNIT(dev);
   1387 	vdc_t	*vdc = NULL;
   1388 	diskaddr_t vio_blkno;
   1389 
   1390 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
   1391 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
   1392 		return (ENXIO);
   1393 	}
   1394 
   1395 	DMSG(vdc, 2, "[%d] dump %ld bytes at block 0x%lx : addr=0x%p\n",
   1396 	    instance, nbytes, blkno, (void *)addr);
   1397 
   1398 	/* convert logical block to vio block */
   1399 	if ((blkno & vdc->vio_bmask) != 0) {
   1400 		DMSG(vdc, 0, "Misaligned block number (%lu)\n", blkno);
   1401 		return (EINVAL);
   1402 	}
   1403 	vio_blkno = blkno >> vdc->vio_bshift;
   1404 
   1405 	rv = vdc_send_request(vdc, VD_OP_BWRITE, addr, nbytes,
   1406 	    VDCPART(dev), vio_blkno, CB_STRATEGY, 0, VIO_write_dir);
   1407 	if (rv) {
   1408 		DMSG(vdc, 0, "Failed to do a disk dump (err=%d)\n", rv);
   1409 		return (rv);
   1410 	}
   1411 
   1412 	if (ddi_in_panic())
   1413 		(void) vdc_drain_response(vdc, CB_STRATEGY, NULL);
   1414 
   1415 	DMSG(vdc, 0, "[%d] End\n", instance);
   1416 
   1417 	return (0);
   1418 }
   1419 
   1420 /* -------------------------------------------------------------------------- */
   1421 
   1422 /*
   1423  * Disk access routines
   1424  *
   1425  */
   1426 
   1427 /*
   1428  * vdc_strategy()
   1429  *
   1430  * Return Value:
   1431  *	0:	As per strategy(9E), the strategy() function must return 0
   1432  *		[ bioerror(9f) sets b_flags to the proper error code ]
   1433  */
   1434 static int
   1435 vdc_strategy(struct buf *buf)
   1436 {
   1437 	diskaddr_t vio_blkno;
   1438 	int	rv = -1;
   1439 	vdc_t	*vdc = NULL;
   1440 	int	instance = VDCUNIT(buf->b_edev);
   1441 	int	op = (buf->b_flags & B_READ) ? VD_OP_BREAD : VD_OP_BWRITE;
   1442 	int	slice;
   1443 
   1444 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
   1445 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
   1446 		bioerror(buf, ENXIO);
   1447 		biodone(buf);
   1448 		return (0);
   1449 	}
   1450 
   1451 	DMSG(vdc, 2, "[%d] %s %ld bytes at block %llx : b_addr=0x%p\n",
   1452 	    instance, (buf->b_flags & B_READ) ? "Read" : "Write",
   1453 	    buf->b_bcount, buf->b_lblkno, (void *)buf->b_un.b_addr);
   1454 
   1455 	bp_mapin(buf);
   1456 
   1457 	if ((long)buf->b_private == VD_SLICE_NONE) {
   1458 		/* I/O using an absolute disk offset */
   1459 		slice = VD_SLICE_NONE;
   1460 	} else {
   1461 		slice = VDCPART(buf->b_edev);
   1462 	}
   1463 
   1464 	/*
   1465 	 * In the buf structure, b_lblkno represents a logical block number
   1466 	 * using a block size of 512 bytes. For the VIO request, this block
   1467 	 * number has to be converted to be represented with the block size
   1468 	 * used by the VIO protocol.
   1469 	 */
   1470 	if ((buf->b_lblkno & vdc->vio_bmask) != 0) {
   1471 		bioerror(buf, EINVAL);
   1472 		biodone(buf);
   1473 		return (0);
   1474 	}
   1475 	vio_blkno = buf->b_lblkno >> vdc->vio_bshift;
   1476 
   1477 	rv = vdc_send_request(vdc, op, (caddr_t)buf->b_un.b_addr,
   1478 	    buf->b_bcount, slice, vio_blkno,
   1479 	    CB_STRATEGY, buf, (op == VD_OP_BREAD) ? VIO_read_dir :
   1480 	    VIO_write_dir);
   1481 
   1482 	/*
   1483 	 * If the request was successfully sent, the strategy call returns and
   1484 	 * the ACK handler calls the bioxxx functions when the vDisk server is
   1485 	 * done otherwise we handle the error here.
   1486 	 */
   1487 	if (rv) {
   1488 		DMSG(vdc, 0, "Failed to read/write (err=%d)\n", rv);
   1489 		bioerror(buf, rv);
   1490 		biodone(buf);
   1491 	} else if (ddi_in_panic()) {
   1492 		rv = vdc_drain_response(vdc, CB_STRATEGY, buf);
   1493 		if (rv != 0) {
   1494 			bioerror(buf, EIO);
   1495 			biodone(buf);
   1496 		}
   1497 	}
   1498 
   1499 	return (0);
   1500 }
   1501 
   1502 /*
   1503  * Function:
   1504  *	vdc_min
   1505  *
   1506  * Description:
   1507  *	Routine to limit the size of a data transfer. Used in
   1508  *	conjunction with physio(9F).
   1509  *
   1510  * Arguments:
   1511  *	bp - pointer to the indicated buf(9S) struct.
   1512  *
   1513  */
   1514 static void
   1515 vdc_min(struct buf *bufp)
   1516 {
   1517 	vdc_t	*vdc = NULL;
   1518 	int	instance = VDCUNIT(bufp->b_edev);
   1519 
   1520 	vdc = ddi_get_soft_state(vdc_state, instance);
   1521 	VERIFY(vdc != NULL);
   1522 
   1523 	if (bufp->b_bcount > (vdc->max_xfer_sz * vdc->vdisk_bsize)) {
   1524 		bufp->b_bcount = vdc->max_xfer_sz * vdc->vdisk_bsize;
   1525 	}
   1526 }
   1527 
   1528 static int
   1529 vdc_read(dev_t dev, struct uio *uio, cred_t *cred)
   1530 {
   1531 	_NOTE(ARGUNUSED(cred))
   1532 
   1533 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
   1534 	return (physio(vdc_strategy, NULL, dev, B_READ, vdc_min, uio));
   1535 }
   1536 
   1537 static int
   1538 vdc_write(dev_t dev, struct uio *uio, cred_t *cred)
   1539 {
   1540 	_NOTE(ARGUNUSED(cred))
   1541 
   1542 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
   1543 	return (physio(vdc_strategy, NULL, dev, B_WRITE, vdc_min, uio));
   1544 }
   1545 
   1546 static int
   1547 vdc_aread(dev_t dev, struct aio_req *aio, cred_t *cred)
   1548 {
   1549 	_NOTE(ARGUNUSED(cred))
   1550 
   1551 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
   1552 	return (aphysio(vdc_strategy, anocancel, dev, B_READ, vdc_min, aio));
   1553 }
   1554 
   1555 static int
   1556 vdc_awrite(dev_t dev, struct aio_req *aio, cred_t *cred)
   1557 {
   1558 	_NOTE(ARGUNUSED(cred))
   1559 
   1560 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
   1561 	return (aphysio(vdc_strategy, anocancel, dev, B_WRITE, vdc_min, aio));
   1562 }
   1563 
   1564 
   1565 /* -------------------------------------------------------------------------- */
   1566 
   1567 /*
   1568  * Handshake support
   1569  */
   1570 
   1571 
   1572 /*
   1573  * Function:
   1574  *	vdc_init_ver_negotiation()
   1575  *
   1576  * Description:
   1577  *
   1578  * Arguments:
   1579  *	vdc	- soft state pointer for this instance of the device driver.
   1580  *
   1581  * Return Code:
   1582  *	0	- Success
   1583  */
   1584 static int
   1585 vdc_init_ver_negotiation(vdc_t *vdc, vio_ver_t ver)
   1586 {
   1587 	vio_ver_msg_t	pkt;
   1588 	size_t		msglen = sizeof (pkt);
   1589 	int		status = -1;
   1590 
   1591 	ASSERT(vdc != NULL);
   1592 	ASSERT(mutex_owned(&vdc->lock));
   1593 
   1594 	DMSG(vdc, 0, "[%d] Entered.\n", vdc->instance);
   1595 
   1596 	/*
   1597 	 * set the Session ID to a unique value
   1598 	 * (the lower 32 bits of the clock tick)
   1599 	 */
   1600 	vdc->session_id = ((uint32_t)gettick() & 0xffffffff);
   1601 	DMSG(vdc, 0, "[%d] Set SID to 0x%lx\n", vdc->instance, vdc->session_id);
   1602 
   1603 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
   1604 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
   1605 	pkt.tag.vio_subtype_env = VIO_VER_INFO;
   1606 	pkt.tag.vio_sid = vdc->session_id;
   1607 	pkt.dev_class = VDEV_DISK;
   1608 	pkt.ver_major = ver.major;
   1609 	pkt.ver_minor = ver.minor;
   1610 
   1611 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
   1612 	DMSG(vdc, 0, "[%d] Ver info sent (status = %d)\n",
   1613 	    vdc->instance, status);
   1614 	if ((status != 0) || (msglen != sizeof (vio_ver_msg_t))) {
   1615 		DMSG(vdc, 0, "[%d] Failed to send Ver negotiation info: "
   1616 		    "id(%lx) rv(%d) size(%ld)", vdc->instance,
   1617 		    vdc->curr_server->ldc_handle, status, msglen);
   1618 		if (msglen != sizeof (vio_ver_msg_t))
   1619 			status = ENOMSG;
   1620 	}
   1621 
   1622 	return (status);
   1623 }
   1624 
   1625 /*
   1626  * Function:
   1627  *	vdc_ver_negotiation()
   1628  *
   1629  * Description:
   1630  *
   1631  * Arguments:
   1632  *	vdcp	- soft state pointer for this instance of the device driver.
   1633  *
   1634  * Return Code:
   1635  *	0	- Success
   1636  */
   1637 static int
   1638 vdc_ver_negotiation(vdc_t *vdcp)
   1639 {
   1640 	vio_msg_t vio_msg;
   1641 	int status;
   1642 
   1643 	if (status = vdc_init_ver_negotiation(vdcp, vdc_version[0]))
   1644 		return (status);
   1645 
   1646 	/* release lock and wait for response */
   1647 	mutex_exit(&vdcp->lock);
   1648 	status = vdc_wait_for_response(vdcp, &vio_msg);
   1649 	mutex_enter(&vdcp->lock);
   1650 	if (status) {
   1651 		DMSG(vdcp, 0,
   1652 		    "[%d] Failed waiting for Ver negotiation response, rv(%d)",
   1653 		    vdcp->instance, status);
   1654 		return (status);
   1655 	}
   1656 
   1657 	/* check type and sub_type ... */
   1658 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
   1659 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
   1660 		DMSG(vdcp, 0, "[%d] Invalid ver negotiation response\n",
   1661 		    vdcp->instance);
   1662 		return (EPROTO);
   1663 	}
   1664 
   1665 	return (vdc_handle_ver_msg(vdcp, (vio_ver_msg_t *)&vio_msg));
   1666 }
   1667 
   1668 /*
   1669  * Function:
   1670  *	vdc_init_attr_negotiation()
   1671  *
   1672  * Description:
   1673  *
   1674  * Arguments:
   1675  *	vdc	- soft state pointer for this instance of the device driver.
   1676  *
   1677  * Return Code:
   1678  *	0	- Success
   1679  */
   1680 static int
   1681 vdc_init_attr_negotiation(vdc_t *vdc)
   1682 {
   1683 	vd_attr_msg_t	pkt;
   1684 	size_t		msglen = sizeof (pkt);
   1685 	int		status;
   1686 
   1687 	ASSERT(vdc != NULL);
   1688 	ASSERT(mutex_owned(&vdc->lock));
   1689 
   1690 	DMSG(vdc, 0, "[%d] entered\n", vdc->instance);
   1691 
   1692 	/* fill in tag */
   1693 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
   1694 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
   1695 	pkt.tag.vio_subtype_env = VIO_ATTR_INFO;
   1696 	pkt.tag.vio_sid = vdc->session_id;
   1697 	/* fill in payload */
   1698 	pkt.max_xfer_sz = vdc->max_xfer_sz;
   1699 	pkt.vdisk_block_size = vdc->vdisk_bsize;
   1700 	pkt.xfer_mode = VIO_DRING_MODE_V1_0;
   1701 	pkt.operations = 0;	/* server will set bits of valid operations */
   1702 	pkt.vdisk_type = 0;	/* server will set to valid device type */
   1703 	pkt.vdisk_media = 0;	/* server will set to valid media type */
   1704 	pkt.vdisk_size = 0;	/* server will set to valid size */
   1705 
   1706 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
   1707 	DMSG(vdc, 0, "Attr info sent (status = %d)\n", status);
   1708 
   1709 	if ((status != 0) || (msglen != sizeof (vd_attr_msg_t))) {
   1710 		DMSG(vdc, 0, "[%d] Failed to send Attr negotiation info: "
   1711 		    "id(%lx) rv(%d) size(%ld)", vdc->instance,
   1712 		    vdc->curr_server->ldc_handle, status, msglen);
   1713 		if (msglen != sizeof (vd_attr_msg_t))
   1714 			status = ENOMSG;
   1715 	}
   1716 
   1717 	return (status);
   1718 }
   1719 
   1720 /*
   1721  * Function:
   1722  *	vdc_attr_negotiation()
   1723  *
   1724  * Description:
   1725  *
   1726  * Arguments:
   1727  *	vdc	- soft state pointer for this instance of the device driver.
   1728  *
   1729  * Return Code:
   1730  *	0	- Success
   1731  */
   1732 static int
   1733 vdc_attr_negotiation(vdc_t *vdcp)
   1734 {
   1735 	int status;
   1736 	vio_msg_t vio_msg;
   1737 
   1738 	if (status = vdc_init_attr_negotiation(vdcp))
   1739 		return (status);
   1740 
   1741 	/* release lock and wait for response */
   1742 	mutex_exit(&vdcp->lock);
   1743 	status = vdc_wait_for_response(vdcp, &vio_msg);
   1744 	mutex_enter(&vdcp->lock);
   1745 	if (status) {
   1746 		DMSG(vdcp, 0,
   1747 		    "[%d] Failed waiting for Attr negotiation response, rv(%d)",
   1748 		    vdcp->instance, status);
   1749 		return (status);
   1750 	}
   1751 
   1752 	/* check type and sub_type ... */
   1753 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
   1754 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
   1755 		DMSG(vdcp, 0, "[%d] Invalid attr negotiation response\n",
   1756 		    vdcp->instance);
   1757 		return (EPROTO);
   1758 	}
   1759 
   1760 	return (vdc_handle_attr_msg(vdcp, (vd_attr_msg_t *)&vio_msg));
   1761 }
   1762 
   1763 
   1764 /*
   1765  * Function:
   1766  *	vdc_init_dring_negotiate()
   1767  *
   1768  * Description:
   1769  *
   1770  * Arguments:
   1771  *	vdc	- soft state pointer for this instance of the device driver.
   1772  *
   1773  * Return Code:
   1774  *	0	- Success
   1775  */
   1776 static int
   1777 vdc_init_dring_negotiate(vdc_t *vdc)
   1778 {
   1779 	vio_dring_reg_msg_t	pkt;
   1780 	size_t			msglen = sizeof (pkt);
   1781 	int			status = -1;
   1782 	int			retry;
   1783 	int			nretries = 10;
   1784 
   1785 	ASSERT(vdc != NULL);
   1786 	ASSERT(mutex_owned(&vdc->lock));
   1787 
   1788 	for (retry = 0; retry < nretries; retry++) {
   1789 		status = vdc_init_descriptor_ring(vdc);
   1790 		if (status != EAGAIN)
   1791 			break;
   1792 		drv_usecwait(vdc_min_timeout_ldc);
   1793 	}
   1794 
   1795 	if (status != 0) {
   1796 		DMSG(vdc, 0, "[%d] Failed to init DRing (status = %d)\n",
   1797 		    vdc->instance, status);
   1798 		return (status);
   1799 	}
   1800 
   1801 	DMSG(vdc, 0, "[%d] Init of descriptor ring completed (status = %d)\n",
   1802 	    vdc->instance, status);
   1803 
   1804 	/* fill in tag */
   1805 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
   1806 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
   1807 	pkt.tag.vio_subtype_env = VIO_DRING_REG;
   1808 	pkt.tag.vio_sid = vdc->session_id;
   1809 	/* fill in payload */
   1810 	pkt.dring_ident = 0;
   1811 	pkt.num_descriptors = vdc->dring_len;
   1812 	pkt.descriptor_size = vdc->dring_entry_size;
   1813 	pkt.options = (VIO_TX_DRING | VIO_RX_DRING);
   1814 	pkt.ncookies = vdc->dring_cookie_count;
   1815 	pkt.cookie[0] = vdc->dring_cookie[0];	/* for now just one cookie */
   1816 
   1817 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
   1818 	if (status != 0) {
   1819 		DMSG(vdc, 0, "[%d] Failed to register DRing (err = %d)",
   1820 		    vdc->instance, status);
   1821 	}
   1822 
   1823 	return (status);
   1824 }
   1825 
   1826 
   1827 /*
   1828  * Function:
   1829  *	vdc_dring_negotiation()
   1830  *
   1831  * Description:
   1832  *
   1833  * Arguments:
   1834  *	vdc	- soft state pointer for this instance of the device driver.
   1835  *
   1836  * Return Code:
   1837  *	0	- Success
   1838  */
   1839 static int
   1840 vdc_dring_negotiation(vdc_t *vdcp)
   1841 {
   1842 	int status;
   1843 	vio_msg_t vio_msg;
   1844 
   1845 	if (status = vdc_init_dring_negotiate(vdcp))
   1846 		return (status);
   1847 
   1848 	/* release lock and wait for response */
   1849 	mutex_exit(&vdcp->lock);
   1850 	status = vdc_wait_for_response(vdcp, &vio_msg);
   1851 	mutex_enter(&vdcp->lock);
   1852 	if (status) {
   1853 		DMSG(vdcp, 0,
   1854 		    "[%d] Failed waiting for Dring negotiation response,"
   1855 		    " rv(%d)", vdcp->instance, status);
   1856 		return (status);
   1857 	}
   1858 
   1859 	/* check type and sub_type ... */
   1860 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
   1861 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
   1862 		DMSG(vdcp, 0, "[%d] Invalid Dring negotiation response\n",
   1863 		    vdcp->instance);
   1864 		return (EPROTO);
   1865 	}
   1866 
   1867 	return (vdc_handle_dring_reg_msg(vdcp,
   1868 	    (vio_dring_reg_msg_t *)&vio_msg));
   1869 }
   1870 
   1871 
   1872 /*
   1873  * Function:
   1874  *	vdc_send_rdx()
   1875  *
   1876  * Description:
   1877  *
   1878  * Arguments:
   1879  *	vdc	- soft state pointer for this instance of the device driver.
   1880  *
   1881  * Return Code:
   1882  *	0	- Success
   1883  */
   1884 static int
   1885 vdc_send_rdx(vdc_t *vdcp)
   1886 {
   1887 	vio_msg_t	msg;
   1888 	size_t		msglen = sizeof (vio_msg_t);
   1889 	int		status;
   1890 
   1891 	/*
   1892 	 * Send an RDX message to vds to indicate we are ready
   1893 	 * to send data
   1894 	 */
   1895 	msg.tag.vio_msgtype = VIO_TYPE_CTRL;
   1896 	msg.tag.vio_subtype = VIO_SUBTYPE_INFO;
   1897 	msg.tag.vio_subtype_env = VIO_RDX;
   1898 	msg.tag.vio_sid = vdcp->session_id;
   1899 	status = vdc_send(vdcp, (caddr_t)&msg, &msglen);
   1900 	if (status != 0) {
   1901 		DMSG(vdcp, 0, "[%d] Failed to send RDX message (%d)",
   1902 		    vdcp->instance, status);
   1903 	}
   1904 
   1905 	return (status);
   1906 }
   1907 
   1908 /*
   1909  * Function:
   1910  *	vdc_handle_rdx()
   1911  *
   1912  * Description:
   1913  *
   1914  * Arguments:
   1915  *	vdc	- soft state pointer for this instance of the device driver.
   1916  *	msgp	- received msg
   1917  *
   1918  * Return Code:
   1919  *	0	- Success
   1920  */
   1921 static int
   1922 vdc_handle_rdx(vdc_t *vdcp, vio_rdx_msg_t *msgp)
   1923 {
   1924 	_NOTE(ARGUNUSED(vdcp))
   1925 	_NOTE(ARGUNUSED(msgp))
   1926 
   1927 	ASSERT(msgp->tag.vio_msgtype == VIO_TYPE_CTRL);
   1928 	ASSERT(msgp->tag.vio_subtype == VIO_SUBTYPE_ACK);
   1929 	ASSERT(msgp->tag.vio_subtype_env == VIO_RDX);
   1930 
   1931 	DMSG(vdcp, 1, "[%d] Got an RDX msg", vdcp->instance);
   1932 
   1933 	return (0);
   1934 }
   1935 
   1936 /*
   1937  * Function:
   1938  *	vdc_rdx_exchange()
   1939  *
   1940  * Description:
   1941  *
   1942  * Arguments:
   1943  *	vdc	- soft state pointer for this instance of the device driver.
   1944  *
   1945  * Return Code:
   1946  *	0	- Success
   1947  */
   1948 static int
   1949 vdc_rdx_exchange(vdc_t *vdcp)
   1950 {
   1951 	int status;
   1952 	vio_msg_t vio_msg;
   1953 
   1954 	if (status = vdc_send_rdx(vdcp))
   1955 		return (status);
   1956 
   1957 	/* release lock and wait for response */
   1958 	mutex_exit(&vdcp->lock);
   1959 	status = vdc_wait_for_response(vdcp, &vio_msg);
   1960 	mutex_enter(&vdcp->lock);
   1961 	if (status) {
   1962 		DMSG(vdcp, 0, "[%d] Failed waiting for RDX response, rv(%d)",
   1963 		    vdcp->instance, status);
   1964 		return (status);
   1965 	}
   1966 
   1967 	/* check type and sub_type ... */
   1968 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
   1969 	    vio_msg.tag.vio_subtype != VIO_SUBTYPE_ACK) {
   1970 		DMSG(vdcp, 0, "[%d] Invalid RDX response\n", vdcp->instance);
   1971 		return (EPROTO);
   1972 	}
   1973 
   1974 	return (vdc_handle_rdx(vdcp, (vio_rdx_msg_t *)&vio_msg));
   1975 }
   1976 
   1977 
   1978 /* -------------------------------------------------------------------------- */
   1979 
   1980 /*
   1981  * LDC helper routines
   1982  */
   1983 
   1984 static int
   1985 vdc_recv(vdc_t *vdc, vio_msg_t *msgp, size_t *nbytesp)
   1986 {
   1987 	int		status;
   1988 	uint64_t	delay_time;
   1989 	size_t		len;
   1990 
   1991 	/*
   1992 	 * Until we get a blocking ldc read we have to retry until the entire
   1993 	 * LDC message has arrived before ldc_read() will return that message.
   1994 	 * If ldc_read() succeed but returns a zero length message then that
   1995 	 * means that the LDC queue is empty and we have to wait for a
   1996 	 * notification from the LDC callback which will set the read_state to
   1997 	 * VDC_READ_PENDING. Note we also bail out if the channel is reset or
   1998 	 * goes away.
   1999 	 */
   2000 	delay_time = vdc_ldc_read_init_delay;
   2001 
   2002 	for (;;) {
   2003 
   2004 		len = *nbytesp;
   2005 		/*
   2006 		 * vdc->curr_server is protected by vdc->lock but to avoid
   2007 		 * contentions we don't take the lock here. We can do this
   2008 		 * safely because vdc_recv() is only called from thread
   2009 		 * process_msg_thread() which is also the only thread that
   2010 		 * can change vdc->curr_server.
   2011 		 */
   2012 		status = ldc_read(vdc->curr_server->ldc_handle,
   2013 		    (caddr_t)msgp, &len);
   2014 
   2015 		if (status == EAGAIN) {
   2016 			delay_time *= 2;
   2017 			if (delay_time >= vdc_ldc_read_max_delay)
   2018 				delay_time = vdc_ldc_read_max_delay;
   2019 			delay(delay_time);
   2020 			continue;
   2021 		}
   2022 
   2023 		if (status != 0) {
   2024 			DMSG(vdc, 0, "ldc_read returned %d\n", status);
   2025 			break;
   2026 		}
   2027 
   2028 		if (len != 0) {
   2029 			*nbytesp = len;
   2030 			break;
   2031 		}
   2032 
   2033 		mutex_enter(&vdc->read_lock);
   2034 
   2035 		while (vdc->read_state != VDC_READ_PENDING) {
   2036 
   2037 			/* detect if the connection has been reset */
   2038 			if (vdc->read_state == VDC_READ_RESET) {
   2039 				mutex_exit(&vdc->read_lock);
   2040 				return (ECONNRESET);
   2041 			}
   2042 
   2043 			vdc->read_state = VDC_READ_WAITING;
   2044 			cv_wait(&vdc->read_cv, &vdc->read_lock);
   2045 		}
   2046 
   2047 		vdc->read_state = VDC_READ_IDLE;
   2048 		mutex_exit(&vdc->read_lock);
   2049 
   2050 		delay_time = vdc_ldc_read_init_delay;
   2051 	}
   2052 
   2053 	return (status);
   2054 }
   2055 
   2056 
   2057 
   2058 #ifdef DEBUG
   2059 void
   2060 vdc_decode_tag(vdc_t *vdcp, vio_msg_t *msg)
   2061 {
   2062 	char *ms, *ss, *ses;
   2063 	switch (msg->tag.vio_msgtype) {
   2064 #define	Q(_s)	case _s : ms = #_s; break;
   2065 	Q(VIO_TYPE_CTRL)
   2066 	Q(VIO_TYPE_DATA)
   2067 	Q(VIO_TYPE_ERR)
   2068 #undef Q
   2069 	default: ms = "unknown"; break;
   2070 	}
   2071 
   2072 	switch (msg->tag.vio_subtype) {
   2073 #define	Q(_s)	case _s : ss = #_s; break;
   2074 	Q(VIO_SUBTYPE_INFO)
   2075 	Q(VIO_SUBTYPE_ACK)
   2076 	Q(VIO_SUBTYPE_NACK)
   2077 #undef Q
   2078 	default: ss = "unknown"; break;
   2079 	}
   2080 
   2081 	switch (msg->tag.vio_subtype_env) {
   2082 #define	Q(_s)	case _s : ses = #_s; break;
   2083 	Q(VIO_VER_INFO)
   2084 	Q(VIO_ATTR_INFO)
   2085 	Q(VIO_DRING_REG)
   2086 	Q(VIO_DRING_UNREG)
   2087 	Q(VIO_RDX)
   2088 	Q(VIO_PKT_DATA)
   2089 	Q(VIO_DESC_DATA)
   2090 	Q(VIO_DRING_DATA)
   2091 #undef Q
   2092 	default: ses = "unknown"; break;
   2093 	}
   2094 
   2095 	DMSG(vdcp, 3, "(%x/%x/%x) message : (%s/%s/%s)\n",
   2096 	    msg->tag.vio_msgtype, msg->tag.vio_subtype,
   2097 	    msg->tag.vio_subtype_env, ms, ss, ses);
   2098 }
   2099 #endif
   2100 
   2101 /*
   2102  * Function:
   2103  *	vdc_send()
   2104  *
   2105  * Description:
   2106  *	The function encapsulates the call to write a message using LDC.
   2107  *	If LDC indicates that the call failed due to the queue being full,
   2108  *	we retry the ldc_write(), otherwise we return the error returned by LDC.
   2109  *
   2110  * Arguments:
   2111  *	ldc_handle	- LDC handle for the channel this instance of vdc uses
   2112  *	pkt		- address of LDC message to be sent
   2113  *	msglen		- the size of the message being sent. When the function
   2114  *			  returns, this contains the number of bytes written.
   2115  *
   2116  * Return Code:
   2117  *	0		- Success.
   2118  *	EINVAL		- pkt or msglen were NULL
   2119  *	ECONNRESET	- The connection was not up.
   2120  *	EWOULDBLOCK	- LDC queue is full
   2121  *	xxx		- other error codes returned by ldc_write
   2122  */
   2123 static int
   2124 vdc_send(vdc_t *vdc, caddr_t pkt, size_t *msglen)
   2125 {
   2126 	size_t	size = 0;
   2127 	int	status = 0;
   2128 	clock_t delay_ticks;
   2129 
   2130 	ASSERT(vdc != NULL);
   2131 	ASSERT(mutex_owned(&vdc->lock));
   2132 	ASSERT(msglen != NULL);
   2133 	ASSERT(*msglen != 0);
   2134 
   2135 #ifdef DEBUG
   2136 	vdc_decode_tag(vdc, (vio_msg_t *)(uintptr_t)pkt);
   2137 #endif
   2138 	/*
   2139 	 * Wait indefinitely to send if channel
   2140 	 * is busy, but bail out if we succeed or
   2141 	 * if the channel closes or is reset.
   2142 	 */
   2143 	delay_ticks = vdc_hz_min_ldc_delay;
   2144 	do {
   2145 		size = *msglen;
   2146 		status = ldc_write(vdc->curr_server->ldc_handle, pkt, &size);
   2147 		if (status == EWOULDBLOCK) {
   2148 			delay(delay_ticks);
   2149 			/* geometric backoff */
   2150 			delay_ticks *= 2;
   2151 			if (delay_ticks > vdc_hz_max_ldc_delay)
   2152 				delay_ticks = vdc_hz_max_ldc_delay;
   2153 		}
   2154 	} while (status == EWOULDBLOCK);
   2155 
   2156 	/* if LDC had serious issues --- reset vdc state */
   2157 	if (status == EIO || status == ECONNRESET) {
   2158 		/* LDC had serious issues --- reset vdc state */
   2159 		mutex_enter(&vdc->read_lock);
   2160 		if ((vdc->read_state == VDC_READ_WAITING) ||
   2161 		    (vdc->read_state == VDC_READ_RESET))
   2162 			cv_signal(&vdc->read_cv);
   2163 		vdc->read_state = VDC_READ_RESET;
   2164 		mutex_exit(&vdc->read_lock);
   2165 
   2166 		/* wake up any waiters in the reset thread */
   2167 		if (vdc->state == VDC_STATE_INIT_WAITING) {
   2168 			DMSG(vdc, 0, "[%d] write reset - "
   2169 			    "vdc is resetting ..\n", vdc->instance);
   2170 			vdc->state = VDC_STATE_RESETTING;
   2171 			cv_signal(&vdc->initwait_cv);
   2172 		}
   2173 
   2174 		return (ECONNRESET);
   2175 	}
   2176 
   2177 	/* return the last size written */
   2178 	*msglen = size;
   2179 
   2180 	return (status);
   2181 }
   2182 
   2183 /*
   2184  * Function:
   2185  *	vdc_get_md_node
   2186  *
   2187  * Description:
   2188  *	Get the MD, the device node for the given disk instance. The
   2189  *	caller is responsible for cleaning up the reference to the
   2190  *	returned MD (mdpp) by calling md_fini_handle().
   2191  *
   2192  * Arguments:
   2193  *	dip	- dev info pointer for this instance of the device driver.
   2194  *	mdpp	- the returned MD.
   2195  *	vd_nodep - the returned device node.
   2196  *
   2197  * Return Code:
   2198  *	0	- Success.
   2199  *	ENOENT	- Expected node or property did not exist.
   2200  *	ENXIO	- Unexpected error communicating with MD framework
   2201  */
   2202 static int
   2203 vdc_get_md_node(dev_info_t *dip, md_t **mdpp, mde_cookie_t *vd_nodep)
   2204 {
   2205 	int		status = ENOENT;
   2206 	char		*node_name = NULL;
   2207 	md_t		*mdp = NULL;
   2208 	int		num_nodes;
   2209 	int		num_vdevs;
   2210 	mde_cookie_t	rootnode;
   2211 	mde_cookie_t	*listp = NULL;
   2212 	boolean_t	found_inst = B_FALSE;
   2213 	int		listsz;
   2214 	int		idx;
   2215 	uint64_t	md_inst;
   2216 	int		obp_inst;
   2217 	int		instance = ddi_get_instance(dip);
   2218 
   2219 	/*
   2220 	 * Get the OBP instance number for comparison with the MD instance
   2221 	 *
   2222 	 * The "cfg-handle" property of a vdc node in an MD contains the MD's
   2223 	 * notion of "instance", or unique identifier, for that node; OBP
   2224 	 * stores the value of the "cfg-handle" MD property as the value of
   2225 	 * the "reg" property on the node in the device tree it builds from
   2226 	 * the MD and passes to Solaris.  Thus, we look up the devinfo node's
   2227 	 * "reg" property value to uniquely identify this device instance.
   2228 	 * If the "reg" property cannot be found, the device tree state is
   2229 	 * presumably so broken that there is no point in continuing.
   2230 	 */
   2231 	if (!ddi_prop_exists(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS, OBP_REG)) {
   2232 		cmn_err(CE_WARN, "'%s' property does not exist", OBP_REG);
   2233 		return (ENOENT);
   2234 	}
   2235 	obp_inst = ddi_prop_get_int(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS,
   2236 	    OBP_REG, -1);
   2237 	DMSGX(1, "[%d] OBP inst=%d\n", instance, obp_inst);
   2238 
   2239 	/*
   2240 	 * We now walk the MD nodes to find the node for this vdisk.
   2241 	 */
   2242 	if ((mdp = md_get_handle()) == NULL) {
   2243 		cmn_err(CE_WARN, "unable to init machine description");
   2244 		return (ENXIO);
   2245 	}
   2246 
   2247 	num_nodes = md_node_count(mdp);
   2248 	ASSERT(num_nodes > 0);
   2249 
   2250 	listsz = num_nodes * sizeof (mde_cookie_t);
   2251 
   2252 	/* allocate memory for nodes */
   2253 	listp = kmem_zalloc(listsz, KM_SLEEP);
   2254 
   2255 	rootnode = md_root_node(mdp);
   2256 	ASSERT(rootnode != MDE_INVAL_ELEM_COOKIE);
   2257 
   2258 	/*
   2259 	 * Search for all the virtual devices, we will then check to see which
   2260 	 * ones are disk nodes.
   2261 	 */
   2262 	num_vdevs = md_scan_dag(mdp, rootnode,
   2263 	    md_find_name(mdp, VDC_MD_VDEV_NAME),
   2264 	    md_find_name(mdp, "fwd"), listp);
   2265 
   2266 	if (num_vdevs <= 0) {
   2267 		cmn_err(CE_NOTE, "No '%s' node found", VDC_MD_VDEV_NAME);
   2268 		status = ENOENT;
   2269 		goto done;
   2270 	}
   2271 
   2272 	DMSGX(1, "[%d] num_vdevs=%d\n", instance, num_vdevs);
   2273 	for (idx = 0; idx < num_vdevs; idx++) {
   2274 		status = md_get_prop_str(mdp, listp[idx], "name", &node_name);
   2275 		if ((status != 0) || (node_name == NULL)) {
   2276 			cmn_err(CE_NOTE, "Unable to get name of node type '%s'"
   2277 			    ": err %d", VDC_MD_VDEV_NAME, status);
   2278 			continue;
   2279 		}
   2280 
   2281 		DMSGX(1, "[%d] Found node '%s'\n", instance, node_name);
   2282 		if (strcmp(VDC_MD_DISK_NAME, node_name) == 0) {
   2283 			status = md_get_prop_val(mdp, listp[idx],
   2284 			    VDC_MD_CFG_HDL, &md_inst);
   2285 			DMSGX(1, "[%d] vdc inst in MD=%lx\n",
   2286 			    instance, md_inst);
   2287 			if ((status == 0) && (md_inst == obp_inst)) {
   2288 				found_inst = B_TRUE;
   2289 				break;
   2290 			}
   2291 		}
   2292 	}
   2293 
   2294 	if (!found_inst) {
   2295 		DMSGX(0, "Unable to find correct '%s' node", VDC_MD_DISK_NAME);
   2296 		status = ENOENT;
   2297 		goto done;
   2298 	}
   2299 	DMSGX(0, "[%d] MD inst=%lx\n", instance, md_inst);
   2300 
   2301 	*vd_nodep = listp[idx];
   2302 	*mdpp = mdp;
   2303 done:
   2304 	kmem_free(listp, listsz);
   2305 	return (status);
   2306 }
   2307 
   2308 /*
   2309  * Function:
   2310  *	vdc_init_ports
   2311  *
   2312  * Description:
   2313  *	Initialize all the ports for this vdisk instance.
   2314  *
   2315  * Arguments:
   2316  *	vdc	- soft state pointer for this instance of the device driver.
   2317  *	mdp	- md pointer
   2318  *	vd_nodep - device md node.
   2319  *
   2320  * Return Code:
   2321  *	0	- Success.
   2322  *	ENOENT	- Expected node or property did not exist.
   2323  */
   2324 static int
   2325 vdc_init_ports(vdc_t *vdc, md_t *mdp, mde_cookie_t vd_nodep)
   2326 {
   2327 	int		status = 0;
   2328 	int		idx;
   2329 	int		num_nodes;
   2330 	int		num_vports;
   2331 	int		num_chans;
   2332 	int		listsz;
   2333 	mde_cookie_t	vd_port;
   2334 	mde_cookie_t	*chanp = NULL;
   2335 	mde_cookie_t	*portp = NULL;
   2336 	vdc_server_t	*srvr;
   2337 	vdc_server_t	*prev_srvr = NULL;
   2338 
   2339 	/*
   2340 	 * We now walk the MD nodes to find the port nodes for this vdisk.
   2341 	 */
   2342 	num_nodes = md_node_count(mdp);
   2343 	ASSERT(num_nodes > 0);
   2344 
   2345 	listsz = num_nodes * sizeof (mde_cookie_t);
   2346 
   2347 	/* allocate memory for nodes */
   2348 	portp = kmem_zalloc(listsz, KM_SLEEP);
   2349 	chanp = kmem_zalloc(listsz, KM_SLEEP);
   2350 
   2351 	num_vports = md_scan_dag(mdp, vd_nodep,
   2352 	    md_find_name(mdp, VDC_MD_PORT_NAME),
   2353 	    md_find_name(mdp, "fwd"), portp);
   2354 	if (num_vports == 0) {
   2355 		DMSGX(0, "Found no '%s' node for '%s' port\n",
   2356 		    VDC_MD_PORT_NAME, VDC_MD_VDEV_NAME);
   2357 		status = ENOENT;
   2358 		goto done;
   2359 	}
   2360 
   2361 	DMSGX(1, "Found %d '%s' node(s) for '%s' port\n",
   2362 	    num_vports, VDC_MD_PORT_NAME, VDC_MD_VDEV_NAME);
   2363 
   2364 	vdc->num_servers = 0;
   2365 	for (idx = 0; idx < num_vports; idx++) {
   2366 
   2367 		/* initialize this port */
   2368 		vd_port = portp[idx];
   2369 		srvr = kmem_zalloc(sizeof (vdc_server_t), KM_SLEEP);
   2370 		srvr->vdcp = vdc;
   2371 
   2372 		/* get port id */
   2373 		if (md_get_prop_val(mdp, vd_port, VDC_MD_ID, &srvr->id) != 0) {
   2374 			cmn_err(CE_NOTE, "vDisk port '%s' property not found",
   2375 			    VDC_MD_ID);
   2376 			kmem_free(srvr, sizeof (vdc_server_t));
   2377 			continue;
   2378 		}
   2379 
   2380 		/* set the connection timeout */
   2381 		if (md_get_prop_val(mdp, vd_port, VDC_MD_TIMEOUT,
   2382 		    &srvr->ctimeout) != 0) {
   2383 			srvr->ctimeout = 0;
   2384 		}
   2385 
   2386 		/* get the ldc id */
   2387 		num_chans = md_scan_dag(mdp, vd_port,
   2388 		    md_find_name(mdp, VDC_MD_CHAN_NAME),
   2389 		    md_find_name(mdp, "fwd"), chanp);
   2390 
   2391 		/* expecting at least one channel */
   2392 		if (num_chans <= 0) {
   2393 			cmn_err(CE_NOTE, "No '%s' node for '%s' port",
   2394 			    VDC_MD_CHAN_NAME, VDC_MD_VDEV_NAME);
   2395 			kmem_free(srvr, sizeof (vdc_server_t));
   2396 			continue;
   2397 		} else if (num_chans != 1) {
   2398 			DMSGX(0, "Expected 1 '%s' node for '%s' port, "
   2399 			    "found %d\n", VDC_MD_CHAN_NAME, VDC_MD_VDEV_NAME,
   2400 			    num_chans);
   2401 		}
   2402 
   2403 		/*
   2404 		 * We use the first channel found (index 0), irrespective of how
   2405 		 * many are there in total.
   2406 		 */
   2407 		if (md_get_prop_val(mdp, chanp[0], VDC_MD_ID,
   2408 		    &srvr->ldc_id) != 0) {
   2409 			cmn_err(CE_NOTE, "Channel '%s' property not found",
   2410 			    VDC_MD_ID);
   2411 			kmem_free(srvr, sizeof (vdc_server_t));
   2412 			continue;
   2413 		}
   2414 
   2415 		/*
   2416 		 * now initialise LDC channel which will be used to
   2417 		 * communicate with this server
   2418 		 */
   2419 		if (vdc_do_ldc_init(vdc, srvr) != 0) {
   2420 			kmem_free(srvr, sizeof (vdc_server_t));
   2421 			continue;
   2422 		}
   2423 
   2424 		/* add server to list */
   2425 		if (prev_srvr)
   2426 			prev_srvr->next = srvr;
   2427 		else
   2428 			vdc->server_list = srvr;
   2429 
   2430 		prev_srvr = srvr;
   2431 
   2432 		/* inc numbers of servers */
   2433 		vdc->num_servers++;
   2434 	}
   2435 
   2436 	/*
   2437 	 * Adjust the max number of handshake retries to match
   2438 	 * the number of vdisk servers.
   2439 	 */
   2440 	if (vdc_hshake_retries < vdc->num_servers)
   2441 		vdc_hshake_retries = vdc->num_servers;
   2442 
   2443 	/* pick first server as current server */
   2444 	if (vdc->server_list != NULL) {
   2445 		vdc->curr_server = vdc->server_list;
   2446 		status = 0;
   2447 	} else {
   2448 		status = ENOENT;
   2449 	}
   2450 
   2451 done:
   2452 	kmem_free(chanp, listsz);
   2453 	kmem_free(portp, listsz);
   2454 	return (status);
   2455 }
   2456 
   2457 
   2458 /*
   2459  * Function:
   2460  *	vdc_do_ldc_up
   2461  *
   2462  * Description:
   2463  *	Bring the channel for the current server up.
   2464  *
   2465  * Arguments:
   2466  *	vdc	- soft state pointer for this instance of the device driver.
   2467  *
   2468  * Return Code:
   2469  *	0		- Success.
   2470  *	EINVAL		- Driver is detaching / LDC error
   2471  *	ECONNREFUSED	- Other end is not listening
   2472  */
   2473 static int
   2474 vdc_do_ldc_up(vdc_t *vdc)
   2475 {
   2476 	int		status;
   2477 	ldc_status_t	ldc_state;
   2478 
   2479 	ASSERT(MUTEX_HELD(&vdc->lock));
   2480 
   2481 	DMSG(vdc, 0, "[%d] Bringing up channel %lx\n",
   2482 	    vdc->instance, vdc->curr_server->ldc_id);
   2483 
   2484 	if (vdc->lifecycle == VDC_LC_DETACHING)
   2485 		return (EINVAL);
   2486 
   2487 	if ((status = ldc_up(vdc->curr_server->ldc_handle)) != 0) {
   2488 		switch (status) {
   2489 		case ECONNREFUSED:	/* listener not ready at other end */
   2490 			DMSG(vdc, 0, "[%d] ldc_up(%lx,...) return %d\n",
   2491 			    vdc->instance, vdc->curr_server->ldc_id, status);
   2492 			status = 0;
   2493 			break;
   2494 		default:
   2495 			DMSG(vdc, 0, "[%d] Failed to bring up LDC: "
   2496 			    "channel=%ld, err=%d", vdc->instance,
   2497 			    vdc->curr_server->ldc_id, status);
   2498 			break;
   2499 		}
   2500 	}
   2501 
   2502 	if (ldc_status(vdc->curr_server->ldc_handle, &ldc_state) == 0) {
   2503 		vdc->curr_server->ldc_state = ldc_state;
   2504 		if (ldc_state == LDC_UP) {
   2505 			DMSG(vdc, 0, "[%d] LDC channel already up\n",
   2506 			    vdc->instance);
   2507 			vdc->seq_num = 1;
   2508 			vdc->seq_num_reply = 0;
   2509 		}
   2510 	}
   2511 
   2512 	return (status);
   2513 }
   2514 
   2515 /*
   2516  * Function:
   2517  *	vdc_terminate_ldc()
   2518  *
   2519  * Description:
   2520  *
   2521  * Arguments:
   2522  *	vdc	- soft state pointer for this instance of the device driver.
   2523  *	srvr	- vdc per-server info structure
   2524  *
   2525  * Return Code:
   2526  *	None
   2527  */
   2528 static void
   2529 vdc_terminate_ldc(vdc_t *vdc, vdc_server_t *srvr)
   2530 {
   2531 	int	instance = ddi_get_instance(vdc->dip);
   2532 
   2533 	if (srvr->state & VDC_LDC_OPEN) {
   2534 		DMSG(vdc, 0, "[%d] ldc_close()\n", instance);
   2535 		(void) ldc_close(srvr->ldc_handle);
   2536 	}
   2537 	if (srvr->state & VDC_LDC_CB) {
   2538 		DMSG(vdc, 0, "[%d] ldc_unreg_callback()\n", instance);
   2539 		(void) ldc_unreg_callback(srvr->ldc_handle);
   2540 	}
   2541 	if (srvr->state & VDC_LDC_INIT) {
   2542 		DMSG(vdc, 0, "[%d] ldc_fini()\n", instance);
   2543 		(void) ldc_fini(srvr->ldc_handle);
   2544 		srvr->ldc_handle = NULL;
   2545 	}
   2546 
   2547 	srvr->state &= ~(VDC_LDC_INIT | VDC_LDC_CB | VDC_LDC_OPEN);
   2548 }
   2549 
   2550 /*
   2551  * Function:
   2552  *	vdc_fini_ports()
   2553  *
   2554  * Description:
   2555  *	Finalize all ports by closing the channel associated with each
   2556  *	port and also freeing the server structure.
   2557  *
   2558  * Arguments:
   2559  *	vdc	- soft state pointer for this instance of the device driver.
   2560  *
   2561  * Return Code:
   2562  *	None
   2563  */
   2564 static void
   2565 vdc_fini_ports(vdc_t *vdc)
   2566 {
   2567 	int		instance = ddi_get_instance(vdc->dip);
   2568 	vdc_server_t	*srvr, *prev_srvr;
   2569 
   2570 	ASSERT(vdc != NULL);
   2571 	ASSERT(mutex_owned(&vdc->lock));
   2572 
   2573 	DMSG(vdc, 0, "[%d] initialized=%x\n", instance, vdc->initialized);
   2574 
   2575 	srvr = vdc->server_list;
   2576 
   2577 	while (srvr) {
   2578 
   2579 		vdc_terminate_ldc(vdc, srvr);
   2580 
   2581 		/* next server */
   2582 		prev_srvr = srvr;
   2583 		srvr = srvr->next;
   2584 
   2585 		/* free server */
   2586 		kmem_free(prev_srvr, sizeof (vdc_server_t));
   2587 	}
   2588 
   2589 	vdc->server_list = NULL;
   2590 }
   2591 
   2592 /* -------------------------------------------------------------------------- */
   2593 
   2594 /*
   2595  * Descriptor Ring helper routines
   2596  */
   2597 
   2598 /*
   2599  * Function:
   2600  *	vdc_init_descriptor_ring()
   2601  *
   2602  * Description:
   2603  *
   2604  * Arguments:
   2605  *	vdc	- soft state pointer for this instance of the device driver.
   2606  *
   2607  * Return Code:
   2608  *	0	- Success
   2609  */
   2610 static int
   2611 vdc_init_descriptor_ring(vdc_t *vdc)
   2612 {
   2613 	vd_dring_entry_t	*dep = NULL;	/* DRing Entry pointer */
   2614 	int	status = 0;
   2615 	int	i;
   2616 
   2617 	DMSG(vdc, 0, "[%d] initialized=%x\n", vdc->instance, vdc->initialized);
   2618 
   2619 	ASSERT(vdc != NULL);
   2620 	ASSERT(mutex_owned(&vdc->lock));
   2621 
   2622 	/* ensure we have enough room to store max sized block */
   2623 	ASSERT(maxphys <= VD_MAX_BLOCK_SIZE);
   2624 
   2625 	if ((vdc->initialized & VDC_DRING_INIT) == 0) {
   2626 		DMSG(vdc, 0, "[%d] ldc_mem_dring_create\n", vdc->instance);
   2627 		/*
   2628 		 * Calculate the maximum block size we can transmit using one
   2629 		 * Descriptor Ring entry from the attributes returned by the
   2630 		 * vDisk server. This is subject to a minimum of 'maxphys'
   2631 		 * as we do not have the capability to split requests over
   2632 		 * multiple DRing entries.
   2633 		 */
   2634 		if ((vdc->max_xfer_sz * vdc->vdisk_bsize) < maxphys) {
   2635 			DMSG(vdc, 0, "[%d] using minimum DRing size\n",
   2636 			    vdc->instance);
   2637 			vdc->dring_max_cookies = maxphys / PAGESIZE;
   2638 		} else {
   2639 			vdc->dring_max_cookies =
   2640 			    (vdc->max_xfer_sz * vdc->vdisk_bsize) / PAGESIZE;
   2641 		}
   2642 		vdc->dring_entry_size = (sizeof (vd_dring_entry_t) +
   2643 		    (sizeof (ldc_mem_cookie_t) *
   2644 		    (vdc->dring_max_cookies - 1)));
   2645 		vdc->dring_len = VD_DRING_LEN;
   2646 
   2647 		status = ldc_mem_dring_create(vdc->dring_len,
   2648 		    vdc->dring_entry_size, &vdc->dring_hdl);
   2649 		if ((vdc->dring_hdl == NULL) || (status != 0)) {
   2650 			DMSG(vdc, 0, "[%d] Descriptor ring creation failed",
   2651 			    vdc->instance);
   2652 			return (status);
   2653 		}
   2654 		vdc->initialized |= VDC_DRING_INIT;
   2655 	}
   2656 
   2657 	if ((vdc->initialized & VDC_DRING_BOUND) == 0) {
   2658 		DMSG(vdc, 0, "[%d] ldc_mem_dring_bind\n", vdc->instance);
   2659 		vdc->dring_cookie =
   2660 		    kmem_zalloc(sizeof (ldc_mem_cookie_t), KM_SLEEP);
   2661 
   2662 		status = ldc_mem_dring_bind(vdc->curr_server->ldc_handle,
   2663 		    vdc->dring_hdl,
   2664 		    LDC_SHADOW_MAP|LDC_DIRECT_MAP, LDC_MEM_RW,
   2665 		    &vdc->dring_cookie[0],
   2666 		    &vdc->dring_cookie_count);
   2667 		if (status != 0) {
   2668 			DMSG(vdc, 0, "[%d] Failed to bind descriptor ring "
   2669 			    "(%lx) to channel (%lx) status=%d\n",
   2670 			    vdc->instance, vdc->dring_hdl,
   2671 			    vdc->curr_server->ldc_handle, status);
   2672 			return (status);
   2673 		}
   2674 		ASSERT(vdc->dring_cookie_count == 1);
   2675 		vdc->initialized |= VDC_DRING_BOUND;
   2676 	}
   2677 
   2678 	status = ldc_mem_dring_info(vdc->dring_hdl, &vdc->dring_mem_info);
   2679 	if (status != 0) {
   2680 		DMSG(vdc, 0,
   2681 		    "[%d] Failed to get info for descriptor ring (%lx)\n",
   2682 		    vdc->instance, vdc->dring_hdl);
   2683 		return (status);
   2684 	}
   2685 
   2686 	if ((vdc->initialized & VDC_DRING_LOCAL) == 0) {
   2687 		DMSG(vdc, 0, "[%d] local dring\n", vdc->instance);
   2688 
   2689 		/* Allocate the local copy of this dring */
   2690 		vdc->local_dring =
   2691 		    kmem_zalloc(vdc->dring_len * sizeof (vdc_local_desc_t),
   2692 		    KM_SLEEP);
   2693 		vdc->initialized |= VDC_DRING_LOCAL;
   2694 	}
   2695 
   2696 	/*
   2697 	 * Mark all DRing entries as free and initialize the private
   2698 	 * descriptor's memory handles. If any entry is initialized,
   2699 	 * we need to free it later so we set the bit in 'initialized'
   2700 	 * at the start.
   2701 	 */
   2702 	vdc->initialized |= VDC_DRING_ENTRY;
   2703 	for (i = 0; i < vdc->dring_len; i++) {
   2704 		dep = VDC_GET_DRING_ENTRY_PTR(vdc, i);
   2705 		dep->hdr.dstate = VIO_DESC_FREE;
   2706 
   2707 		status = ldc_mem_alloc_handle(vdc->curr_server->ldc_handle,
   2708 		    &vdc->local_dring[i].desc_mhdl);
   2709 		if (status != 0) {
   2710 			DMSG(vdc, 0, "![%d] Failed to alloc mem handle for"
   2711 			    " descriptor %d", vdc->instance, i);
   2712 			return (status);
   2713 		}
   2714 		vdc->local_dring[i].is_free = B_TRUE;
   2715 		vdc->local_dring[i].dep = dep;
   2716 	}
   2717 
   2718 	/* Initialize the starting index */
   2719 	vdc->dring_curr_idx = 0;
   2720 
   2721 	return (status);
   2722 }
   2723 
   2724 /*
   2725  * Function:
   2726  *	vdc_destroy_descriptor_ring()
   2727  *
   2728  * Description:
   2729  *
   2730  * Arguments:
   2731  *	vdc	- soft state pointer for this instance of the device driver.
   2732  *
   2733  * Return Code:
   2734  *	None
   2735  */
   2736 static void
   2737 vdc_destroy_descriptor_ring(vdc_t *vdc)
   2738 {
   2739 	vdc_local_desc_t	*ldep = NULL;	/* Local Dring Entry Pointer */
   2740 	ldc_mem_handle_t	mhdl = NULL;
   2741 	ldc_mem_info_t		minfo;
   2742 	int			status = -1;
   2743 	int			i;	/* loop */
   2744 
   2745 	ASSERT(vdc != NULL);
   2746 	ASSERT(mutex_owned(&vdc->lock));
   2747 
   2748 	DMSG(vdc, 0, "[%d] Entered\n", vdc->instance);
   2749 
   2750 	if (vdc->initialized & VDC_DRING_ENTRY) {
   2751 		DMSG(vdc, 0,
   2752 		    "[%d] Removing Local DRing entries\n", vdc->instance);
   2753 		for (i = 0; i < vdc->dring_len; i++) {
   2754 			ldep = &vdc->local_dring[i];
   2755 			mhdl = ldep->desc_mhdl;
   2756 
   2757 			if (mhdl == NULL)
   2758 				continue;
   2759 
   2760 			if ((status = ldc_mem_info(mhdl, &minfo)) != 0) {
   2761 				DMSG(vdc, 0,
   2762 				    "ldc_mem_info returned an error: %d\n",
   2763 				    status);
   2764 
   2765 				/*
   2766 				 * This must mean that the mem handle
   2767 				 * is not valid. Clear it out so that
   2768 				 * no one tries to use it.
   2769 				 */
   2770 				ldep->desc_mhdl = NULL;
   2771 				continue;
   2772 			}
   2773 
   2774 			if (minfo.status == LDC_BOUND) {
   2775 				(void) ldc_mem_unbind_handle(mhdl);
   2776 			}
   2777 
   2778 			(void) ldc_mem_free_handle(mhdl);
   2779 
   2780 			ldep->desc_mhdl = NULL;
   2781 		}
   2782 		vdc->initialized &= ~VDC_DRING_ENTRY;
   2783 	}
   2784 
   2785 	if (vdc->initialized & VDC_DRING_LOCAL) {
   2786 		DMSG(vdc, 0, "[%d] Freeing Local DRing\n", vdc->instance);
   2787 		kmem_free(vdc->local_dring,
   2788 		    vdc->dring_len * sizeof (vdc_local_desc_t));
   2789 		vdc->initialized &= ~VDC_DRING_LOCAL;
   2790 	}
   2791 
   2792 	if (vdc->initialized & VDC_DRING_BOUND) {
   2793 		DMSG(vdc, 0, "[%d] Unbinding DRing\n", vdc->instance);
   2794 		status = ldc_mem_dring_unbind(vdc->dring_hdl);
   2795 		if (status == 0) {
   2796 			vdc->initialized &= ~VDC_DRING_BOUND;
   2797 		} else {
   2798 			DMSG(vdc, 0, "[%d] Error %d unbinding DRing %lx",
   2799 			    vdc->instance, status, vdc->dring_hdl);
   2800 		}
   2801 		kmem_free(vdc->dring_cookie, sizeof (ldc_mem_cookie_t));
   2802 	}
   2803 
   2804 	if (vdc->initialized & VDC_DRING_INIT) {
   2805 		DMSG(vdc, 0, "[%d] Destroying DRing\n", vdc->instance);
   2806 		status = ldc_mem_dring_destroy(vdc->dring_hdl);
   2807 		if (status == 0) {
   2808 			vdc->dring_hdl = NULL;
   2809 			bzero(&vdc->dring_mem_info, sizeof (ldc_mem_info_t));
   2810 			vdc->initialized &= ~VDC_DRING_INIT;
   2811 		} else {
   2812 			DMSG(vdc, 0, "[%d] Error %d destroying DRing (%lx)",
   2813 			    vdc->instance, status, vdc->dring_hdl);
   2814 		}
   2815 	}
   2816 }
   2817 
   2818 /*
   2819  * Function:
   2820  *	vdc_map_to_shared_dring()
   2821  *
   2822  * Description:
   2823  *	Copy contents of the local descriptor to the shared
   2824  *	memory descriptor.
   2825  *
   2826  * Arguments:
   2827  *	vdcp	- soft state pointer for this instance of the device driver.
   2828  *	idx	- descriptor ring index
   2829  *
   2830  * Return Code:
   2831  *	None
   2832  */
   2833 static int
   2834 vdc_map_to_shared_dring(vdc_t *vdcp, int idx)
   2835 {
   2836 	vdc_local_desc_t	*ldep;
   2837 	vd_dring_entry_t	*dep;
   2838 	int			rv;
   2839 
   2840 	ldep = &(vdcp->local_dring[idx]);
   2841 
   2842 	/* for now leave in the old pop_mem_hdl stuff */
   2843 	if (ldep->nbytes > 0) {
   2844 		rv = vdc_populate_mem_hdl(vdcp, ldep);
   2845 		if (rv) {
   2846 			DMSG(vdcp, 0, "[%d] Cannot populate mem handle\n",
   2847 			    vdcp->instance);
   2848 			return (rv);
   2849 		}
   2850 	}
   2851 
   2852 	/*
   2853 	 * fill in the data details into the DRing
   2854 	 */
   2855 	dep = ldep->dep;
   2856 	ASSERT(dep != NULL);
   2857 
   2858 	dep->payload.req_id = VDC_GET_NEXT_REQ_ID(vdcp);
   2859 	dep->payload.operation = ldep->operation;
   2860 	dep->payload.addr = ldep->offset;
   2861 	dep->payload.nbytes = ldep->nbytes;
   2862 	dep->payload.status = (uint32_t)-1;	/* vds will set valid value */
   2863 	dep->payload.slice = ldep->slice;
   2864 	dep->hdr.dstate = VIO_DESC_READY;
   2865 	dep->hdr.ack = 1;		/* request an ACK for every message */
   2866 
   2867 	return (0);
   2868 }
   2869 
   2870 /*
   2871  * Function:
   2872  *	vdc_send_request
   2873  *
   2874  * Description:
   2875  *	This routine writes the data to be transmitted to vds into the
   2876  *	descriptor, notifies vds that the ring has been updated and
   2877  *	then waits for the request to be processed.
   2878  *
   2879  * Arguments:
   2880  *	vdcp	  - the soft state pointer
   2881  *	operation - operation we want vds to perform (VD_OP_XXX)
   2882  *	addr	  - address of data buf to be read/written.
   2883  *	nbytes	  - number of bytes to read/write
   2884  *	slice	  - the disk slice this request is for
   2885  *	offset	  - relative disk offset
   2886  *	cb_type   - type of call - STRATEGY or SYNC
   2887  *	cb_arg	  - parameter to be sent to server (depends on VD_OP_XXX type)
   2888  *			. mode for ioctl(9e)
   2889  *			. LP64 diskaddr_t (block I/O)
   2890  *	dir	  - direction of operation (READ/WRITE/BOTH)
   2891  *
   2892  * Return Codes:
   2893  *	0
   2894  *	ENXIO
   2895  */
   2896 static int
   2897 vdc_send_request(vdc_t *vdcp, int operation, caddr_t addr,
   2898     size_t nbytes, int slice, diskaddr_t offset, int cb_type,
   2899     void *cb_arg, vio_desc_direction_t dir)
   2900 {
   2901 	int	rv = 0;
   2902 
   2903 	ASSERT(vdcp != NULL);
   2904 	ASSERT(slice == VD_SLICE_NONE || slice < V_NUMPAR);
   2905 
   2906 	mutex_enter(&vdcp->lock);
   2907 
   2908 	/*
   2909 	 * If this is a block read/write operation we update the I/O statistics
   2910 	 * to indicate that the request is being put on the waitq to be
   2911 	 * serviced.
   2912 	 *
   2913 	 * We do it here (a common routine for both synchronous and strategy
   2914 	 * calls) for performance reasons - we are already holding vdc->lock
   2915 	 * so there is no extra locking overhead. We would have to explicitly
   2916 	 * grab the 'lock' mutex to update the stats if we were to do this
   2917 	 * higher up the stack in vdc_strategy() et. al.
   2918 	 */
   2919 	if ((operation == VD_OP_BREAD) || (operation == VD_OP_BWRITE)) {
   2920 		DTRACE_IO1(start, buf_t *, cb_arg);
   2921 		VD_KSTAT_WAITQ_ENTER(vdcp);
   2922 	}
   2923 
   2924 	do {
   2925 		while (vdcp->state != VDC_STATE_RUNNING) {
   2926 
   2927 			/* return error if detaching */
   2928 			if (vdcp->state == VDC_STATE_DETACH) {
   2929 				rv = ENXIO;
   2930 				goto done;
   2931 			}
   2932 
   2933 			/* fail request if connection timeout is reached */
   2934 			if (vdcp->ctimeout_reached) {
   2935 				rv = EIO;
   2936 				goto done;
   2937 			}
   2938 
   2939 			/*
   2940 			 * If we are panicking and the disk is not ready then
   2941 			 * we can't send any request because we can't complete
   2942 			 * the handshake now.
   2943 			 */
   2944 			if (ddi_in_panic()) {
   2945 				rv = EIO;
   2946 				goto done;
   2947 			}
   2948 
   2949 			cv_wait(&vdcp->running_cv, &vdcp->lock);
   2950 		}
   2951 
   2952 	} while (vdc_populate_descriptor(vdcp, operation, addr,
   2953 	    nbytes, slice, offset, cb_type, cb_arg, dir));
   2954 
   2955 done:
   2956 	/*
   2957 	 * If this is a block read/write we update the I/O statistics kstat
   2958 	 * to indicate that this request has been placed on the queue for
   2959 	 * processing (i.e sent to the vDisk server) - iostat(1M) will
   2960 	 * report the time waiting for the vDisk server under the %b column
   2961 	 * In the case of an error we simply take it off the wait queue.
   2962 	 */
   2963 	if ((operation == VD_OP_BREAD) || (operation == VD_OP_BWRITE)) {
   2964 		if (rv == 0) {
   2965 			VD_KSTAT_WAITQ_TO_RUNQ(vdcp);
   2966 			DTRACE_PROBE1(send, buf_t *, cb_arg);
   2967 		} else {
   2968 			VD_UPDATE_ERR_STATS(vdcp, vd_transerrs);
   2969 			VD_KSTAT_WAITQ_EXIT(vdcp);
   2970 			DTRACE_IO1(done, buf_t *, cb_arg);
   2971 		}
   2972 	}
   2973 
   2974 	mutex_exit(&vdcp->lock);
   2975 
   2976 	return (rv);
   2977 }
   2978 
   2979 
   2980 /*
   2981  * Function:
   2982  *	vdc_populate_descriptor
   2983  *
   2984  * Description:
   2985  *	This routine writes the data to be transmitted to vds into the
   2986  *	descriptor, notifies vds that the ring has been updated and
   2987  *	then waits for the request to be processed.
   2988  *
   2989  * Arguments:
   2990  *	vdcp	  - the soft state pointer
   2991  *	operation - operation we want vds to perform (VD_OP_XXX)
   2992  *	addr	  - address of data buf to be read/written.
   2993  *	nbytes	  - number of bytes to read/write
   2994  *	slice	  - the disk slice this request is for
   2995  *	offset	  - relative disk offset
   2996  *	cb_type   - type of call - STRATEGY or SYNC
   2997  *	cb_arg	  - parameter to be sent to server (depends on VD_OP_XXX type)
   2998  *			. mode for ioctl(9e)
   2999  *			. LP64 diskaddr_t (block I/O)
   3000  *	dir	  - direction of operation (READ/WRITE/BOTH)
   3001  *
   3002  * Return Codes:
   3003  *	0
   3004  *	EAGAIN
   3005  *	ECONNRESET
   3006  *	ENXIO
   3007  */
   3008 static int
   3009 vdc_populate_descriptor(vdc_t *vdcp, int operation, caddr_t addr,
   3010     size_t nbytes, int slice, diskaddr_t offset, int cb_type,
   3011     void *cb_arg, vio_desc_direction_t dir)
   3012 {
   3013 	vdc_local_desc_t	*local_dep = NULL; /* Local Dring Pointer */
   3014 	int			idx;		/* Index of DRing entry used */
   3015 	int			next_idx;
   3016 	vio_dring_msg_t		dmsg;
   3017 	size_t			msglen;
   3018 	int			rv;
   3019 
   3020 	ASSERT(MUTEX_HELD(&vdcp->lock));
   3021 	vdcp->threads_pending++;
   3022 loop:
   3023 	DMSG(vdcp, 2, ": dring_curr_idx = %d\n", vdcp->dring_curr_idx);
   3024 
   3025 	/* Get next available D-Ring entry */
   3026 	idx = vdcp->dring_curr_idx;
   3027 	local_dep = &(vdcp->local_dring[idx]);
   3028 
   3029 	if (!local_dep->is_free) {
   3030 		DMSG(vdcp, 2, "[%d]: dring full - waiting for space\n",
   3031 		    vdcp->instance);
   3032 		cv_wait(&vdcp->dring_free_cv, &vdcp->lock);
   3033 		if (vdcp->state == VDC_STATE_RUNNING ||
   3034 		    vdcp->state == VDC_STATE_HANDLE_PENDING) {
   3035 			goto loop;
   3036 		}
   3037 		vdcp->threads_pending--;
   3038 		return (ECONNRESET);
   3039 	}
   3040 
   3041 	next_idx = idx + 1;
   3042 	if (next_idx >= vdcp->dring_len)
   3043 		next_idx = 0;
   3044 	vdcp->dring_curr_idx = next_idx;
   3045 
   3046 	ASSERT(local_dep->is_free);
   3047 
   3048 	local_dep->operation = operation;
   3049 	local_dep->addr = addr;
   3050 	local_dep->nbytes = nbytes;
   3051 	local_dep->slice = slice;
   3052 	local_dep->offset = offset;
   3053 	local_dep->cb_type = cb_type;
   3054 	local_dep->cb_arg = cb_arg;
   3055 	local_dep->dir = dir;
   3056 
   3057 	local_dep->is_free = B_FALSE;
   3058 
   3059 	rv = vdc_map_to_shared_dring(vdcp, idx);
   3060 	if (rv) {
   3061 		DMSG(vdcp, 0, "[%d]: cannot bind memory - waiting ..\n",
   3062 		    vdcp->instance);
   3063 		/* free the descriptor */
   3064 		local_dep->is_free = B_TRUE;
   3065 		vdcp->dring_curr_idx = idx;
   3066 		cv_wait(&vdcp->membind_cv, &vdcp->lock);
   3067 		if (vdcp->state == VDC_STATE_RUNNING ||
   3068 		    vdcp->state == VDC_STATE_HANDLE_PENDING) {
   3069 			goto loop;
   3070 		}
   3071 		vdcp->threads_pending--;
   3072 		return (ECONNRESET);
   3073 	}
   3074 
   3075 	/*
   3076 	 * Send a msg with the DRing details to vds
   3077 	 */
   3078 	VIO_INIT_DRING_DATA_TAG(dmsg);
   3079 	VDC_INIT_DRING_DATA_MSG_IDS(dmsg, vdcp);
   3080 	dmsg.dring_ident = vdcp->dring_ident;
   3081 	dmsg.start_idx = idx;
   3082 	dmsg.end_idx = idx;
   3083 	vdcp->seq_num++;
   3084 
   3085 	DTRACE_PROBE2(populate, int, vdcp->instance,
   3086 	    vdc_local_desc_t *, local_dep);
   3087 	DMSG(vdcp, 2, "ident=0x%lx, st=%u, end=%u, seq=%ld\n",
   3088 	    vdcp->dring_ident, dmsg.start_idx, dmsg.end_idx, dmsg.seq_num);
   3089 
   3090 	/*
   3091 	 * note we're still holding the lock here to
   3092 	 * make sure the message goes out in order !!!...
   3093 	 */
   3094 	msglen = sizeof (dmsg);
   3095 	rv = vdc_send(vdcp, (caddr_t)&dmsg, &msglen);
   3096 	switch (rv) {
   3097 	case ECONNRESET:
   3098 		/*
   3099 		 * vdc_send initiates the reset on failure.
   3100 		 * Since the transaction has already been put
   3101 		 * on the local dring, it will automatically get
   3102 		 * retried when the channel is reset. Given that,
   3103 		 * it is ok to just return success even though the
   3104 		 * send failed.
   3105 		 */
   3106 		rv = 0;
   3107 		break;
   3108 
   3109 	case 0: /* EOK */
   3110 		DMSG(vdcp, 1, "sent via LDC: rv=%d\n", rv);
   3111 		break;
   3112 
   3113 	default:
   3114 		goto cleanup_and_exit;
   3115 	}
   3116 
   3117 	vdcp->threads_pending--;
   3118 	return (rv);
   3119 
   3120 cleanup_and_exit:
   3121 	DMSG(vdcp, 0, "unexpected error, rv=%d\n", rv);
   3122 	return (ENXIO);
   3123 }
   3124 
   3125 /*
   3126  * Function:
   3127  *	vdc_do_sync_op
   3128  *
   3129  * Description:
   3130  * 	Wrapper around vdc_populate_descriptor that blocks until the
   3131  * 	response to the message is available.
   3132  *
   3133  * Arguments:
   3134  *	vdcp	  - the soft state pointer
   3135  *	operation - operation we want vds to perform (VD_OP_XXX)
   3136  *	addr	  - address of data buf to be read/written.
   3137  *	nbytes	  - number of bytes to read/write
   3138  *	slice	  - the disk slice this request is for
   3139  *	offset	  - relative disk offset
   3140  *	cb_type   - type of call - STRATEGY or SYNC
   3141  *	cb_arg	  - parameter to be sent to server (depends on VD_OP_XXX type)
   3142  *			. mode for ioctl(9e)
   3143  *			. LP64 diskaddr_t (block I/O)
   3144  *	dir	  - direction of operation (READ/WRITE/BOTH)
   3145  *	rconflict - check for reservation conflict in case of failure
   3146  *
   3147  * rconflict should be set to B_TRUE by most callers. Callers invoking the
   3148  * VD_OP_SCSICMD operation can set rconflict to B_FALSE if they check the
   3149  * result of a successful operation with vd_scsi_status().
   3150  *
   3151  * Return Codes:
   3152  *	0
   3153  *	EAGAIN
   3154  *	EFAULT
   3155  *	ENXIO
   3156  *	EIO
   3157  */
   3158 static int
   3159 vdc_do_sync_op(vdc_t *vdcp, int operation, caddr_t addr, size_t nbytes,
   3160     int slice, diskaddr_t offset, int cb_type, void *cb_arg,
   3161     vio_desc_direction_t dir, boolean_t rconflict)
   3162 {
   3163 	int status;
   3164 	vdc_io_t *vio;
   3165 	boolean_t check_resv_conflict = B_FALSE;
   3166 
   3167 	ASSERT(cb_type == CB_SYNC);
   3168 
   3169 	/*
   3170 	 * Grab the lock, if blocked wait until the server
   3171 	 * response causes us to wake up again.
   3172 	 */
   3173 	mutex_enter(&vdcp->lock);
   3174 	vdcp->sync_op_cnt++;
   3175 	while (vdcp->sync_op_blocked && vdcp->state != VDC_STATE_DETACH) {
   3176 		if (ddi_in_panic()) {
   3177 			/* don't block if we are panicking */
   3178 			vdcp->sync_op_cnt--;
   3179 			mutex_exit(&vdcp->lock);
   3180 			return (EIO);
   3181 		} else {
   3182 			cv_wait(&vdcp->sync_blocked_cv, &vdcp->lock);
   3183 		}
   3184 	}
   3185 
   3186 	if (vdcp->state == VDC_STATE_DETACH) {
   3187 		cv_broadcast(&vdcp->sync_blocked_cv);
   3188 		vdcp->sync_op_cnt--;
   3189 		mutex_exit(&vdcp->lock);
   3190 		return (ENXIO);
   3191 	}
   3192 
   3193 	/* now block anyone other thread entering after us */
   3194 	vdcp->sync_op_blocked = B_TRUE;
   3195 	vdcp->sync_op_pending = B_TRUE;
   3196 	mutex_exit(&vdcp->lock);
   3197 
   3198 	status = vdc_send_request(vdcp, operation, addr,
   3199 	    nbytes, slice, offset, cb_type, cb_arg, dir);
   3200 
   3201 	mutex_enter(&vdcp->lock);
   3202 
   3203 	if (status != 0) {
   3204 		vdcp->sync_op_pending = B_FALSE;
   3205 	} else if (ddi_in_panic()) {
   3206 		if (vdc_drain_response(vdcp, CB_SYNC, NULL) == 0) {
   3207 			status = vdcp->sync_op_status;
   3208 		} else {
   3209 			vdcp->sync_op_pending = B_FALSE;
   3210 			status = EIO;
   3211 		}
   3212 	} else {
   3213 		/*
   3214 		 * block until our transaction completes.
   3215 		 * Also anyone else waiting also gets to go next.
   3216 		 */
   3217 		while (vdcp->sync_op_pending && vdcp->state != VDC_STATE_DETACH)
   3218 			cv_wait(&vdcp->sync_pending_cv, &vdcp->lock);
   3219 
   3220 		DMSG(vdcp, 2, ": operation returned %d\n",
   3221 		    vdcp->sync_op_status);
   3222 		if (vdcp->state == VDC_STATE_DETACH) {
   3223 			vdcp->sync_op_pending = B_FALSE;
   3224 			status = ENXIO;
   3225 		} else {
   3226 			status = vdcp->sync_op_status;
   3227 			if (status != 0 && vdcp->failfast_interval != 0) {
   3228 				/*
   3229 				 * Operation has failed and failfast is enabled.
   3230 				 * We need to check if the failure is due to a
   3231 				 * reservation conflict if this was requested.
   3232 				 */
   3233 				check_resv_conflict = rconflict;
   3234 			}
   3235 
   3236 		}
   3237 	}
   3238 
   3239 	vdcp->sync_op_status = 0;
   3240 	vdcp->sync_op_blocked = B_FALSE;
   3241 	vdcp->sync_op_cnt--;
   3242 
   3243 	/* signal the next waiting thread */
   3244 	cv_signal(&vdcp->sync_blocked_cv);
   3245 
   3246 	/*
   3247 	 * We have to check for reservation conflict after unblocking sync
   3248 	 * operations because some sync operations will be used to do this
   3249 	 * check.
   3250 	 */
   3251 	if (check_resv_conflict) {
   3252 		vio = vdc_failfast_io_queue(vdcp, NULL);
   3253 		while (vio->vio_qtime != 0)
   3254 			cv_wait(&vdcp->failfast_io_cv, &vdcp->lock);
   3255 		kmem_free(vio, sizeof (vdc_io_t));
   3256 	}
   3257 
   3258 	mutex_exit(&vdcp->lock);
   3259 
   3260 	return (status);
   3261 }
   3262 
   3263 
   3264 /*
   3265  * Function:
   3266  *	vdc_drain_response()
   3267  *
   3268  * Description:
   3269  * 	When a guest is panicking, the completion of requests needs to be
   3270  * 	handled differently because interrupts are disabled and vdc
   3271  * 	will not get messages. We have to poll for the messages instead.
   3272  *
   3273  *	Note: since we are panicking we don't implement	the io:::done
   3274  *	DTrace probe or update the I/O statistics kstats.
   3275  *
   3276  * Arguments:
   3277  *	vdc	- soft state pointer for this instance of the device driver.
   3278  *	cb_type	- the type of request we want to drain. If type is CB_SYNC
   3279  *		  then we drain all responses until we find a CB_SYNC request.
   3280  *		  If the type is CB_STRATEGY then the behavior depends on the
   3281  *		  value of the buf argument.
   3282  *	buf	- if the cb_type argument is CB_SYNC then the buf argument
   3283  *		  must be NULL. If the cb_type argument is CB_STRATEGY and
   3284  *		  if buf is NULL then we drain all responses, otherwise we
   3285  *		  poll until we receive a ACK/NACK for the specific I/O
   3286  *		  described by buf.
   3287  *
   3288  * Return Code:
   3289  *	0	- Success. If we were expecting a response to a particular
   3290  *		  CB_SYNC or CB_STRATEGY request then this means that a
   3291  *		  response has been received.
   3292  */
   3293 static int
   3294 vdc_drain_response(vdc_t *vdc, vio_cb_type_t cb_type, struct buf *buf)
   3295 {
   3296 	int 			rv, idx, retries;
   3297 	size_t			msglen;
   3298 	vdc_local_desc_t 	*ldep = NULL;	/* Local Dring Entry Pointer */
   3299 	vio_dring_msg_t		dmsg;
   3300 	struct buf		*mbuf;
   3301 	boolean_t		ack;
   3302 
   3303 	ASSERT(cb_type == CB_STRATEGY || cb_type == CB_SYNC);
   3304 
   3305 	mutex_enter(&vdc->lock);
   3306 
   3307 	retries = 0;
   3308 	for (;;) {
   3309 		msglen = sizeof (dmsg);
   3310 		rv = ldc_read(vdc->curr_server->ldc_handle, (caddr_t)&dmsg,
   3311 		    &msglen);
   3312 		if (rv) {
   3313 			rv = EINVAL;
   3314 			break;
   3315 		}
   3316 
   3317 		/*
   3318 		 * if there are no packets wait and check again
   3319 		 */
   3320 		if ((rv == 0) && (msglen == 0)) {
   3321 			if (retries++ > vdc_dump_retries) {
   3322 				rv = EAGAIN;
   3323 				break;
   3324 			}
   3325 
   3326 			drv_usecwait(vdc_usec_timeout_dump);
   3327 			continue;
   3328 		}
   3329 
   3330 		/*
   3331 		 * Ignore all messages that are not ACKs/NACKs to
   3332 		 * DRing requests.
   3333 		 */
   3334 		if ((dmsg.tag.vio_msgtype != VIO_TYPE_DATA) ||
   3335 		    (dmsg.tag.vio_subtype_env != VIO_DRING_DATA)) {
   3336 			DMSG(vdc, 0, "discard pkt: type=%d sub=%d env=%d\n",
   3337 			    dmsg.tag.vio_msgtype,
   3338 			    dmsg.tag.vio_subtype,
   3339 			    dmsg.tag.vio_subtype_env);
   3340 			continue;
   3341 		}
   3342 
   3343 		/*
   3344 		 * Record if the packet was ACK'ed or not. If the packet was not
   3345 		 * ACK'ed then we will just mark the request as failed; we don't
   3346 		 * want to reset the connection at this point.
   3347 		 */
   3348 		switch (dmsg.tag.vio_subtype) {
   3349 		case VIO_SUBTYPE_ACK:
   3350 			ack = B_TRUE;
   3351 			break;
   3352 		case VIO_SUBTYPE_NACK:
   3353 			ack = B_FALSE;
   3354 			break;
   3355 		default:
   3356 			continue;
   3357 		}
   3358 
   3359 		idx = dmsg.start_idx;
   3360 		if (idx >= vdc->dring_len) {
   3361 			DMSG(vdc, 0, "[%d] Bogus ack data : start %d\n",
   3362 			    vdc->instance, idx);
   3363 			continue;
   3364 		}
   3365 		ldep = &vdc->local_dring[idx];
   3366 		if (ldep->dep->hdr.dstate != VIO_DESC_DONE) {
   3367 			DMSG(vdc, 0, "[%d] Entry @ %d - state !DONE %d\n",
   3368 			    vdc->instance, idx, ldep->dep->hdr.dstate);
   3369 			continue;
   3370 		}
   3371 
   3372 		switch (ldep->cb_type) {
   3373 
   3374 		case CB_STRATEGY:
   3375 			mbuf = ldep->cb_arg;
   3376 			if (mbuf != NULL) {
   3377 				mbuf->b_resid = mbuf->b_bcount -
   3378 				    ldep->dep->payload.nbytes;
   3379 				bioerror(mbuf,
   3380 				    ack ? ldep->dep->payload.status : EIO);
   3381 				biodone(mbuf);
   3382 			}
   3383 			rv = vdc_depopulate_descriptor(vdc, idx);
   3384 			if (buf != NULL && buf == mbuf) {
   3385 				rv = 0;
   3386 				goto done;
   3387 			}
   3388 			break;
   3389 
   3390 		case CB_SYNC:
   3391 			rv = vdc_depopulate_descriptor(vdc, idx);
   3392 			vdc->sync_op_status = ack ? rv : EIO;
   3393 			vdc->sync_op_pending = B_FALSE;
   3394 			cv_signal(&vdc->sync_pending_cv);
   3395 			if (cb_type == CB_SYNC) {
   3396 				rv = 0;
   3397 				goto done;
   3398 			}
   3399 			break;
   3400 		}
   3401 
   3402 		/* if this is the last descriptor - break out of loop */
   3403 		if ((idx + 1) % vdc->dring_len == vdc->dring_curr_idx) {
   3404 			/*
   3405 			 * If we were expecting a response for a particular
   3406 			 * request then we return with an error otherwise we
   3407 			 * have successfully completed the drain.
   3408 			 */
   3409 			rv = (buf != NULL || cb_type == CB_SYNC)? ESRCH: 0;
   3410 			break;
   3411 		}
   3412 	}
   3413 
   3414 done:
   3415 	mutex_exit(&vdc->lock);
   3416 	DMSG(vdc, 0, "End idx=%d\n", idx);
   3417 
   3418 	return (rv);
   3419 }
   3420 
   3421 
   3422 /*
   3423  * Function:
   3424  *	vdc_depopulate_descriptor()
   3425  *
   3426  * Description:
   3427  *
   3428  * Arguments:
   3429  *	vdc	- soft state pointer for this instance of the device driver.
   3430  *	idx	- Index of the Descriptor Ring entry being modified
   3431  *
   3432  * Return Code:
   3433  *	0	- Success
   3434  */
   3435 static int
   3436 vdc_depopulate_descriptor(vdc_t *vdc, uint_t idx)
   3437 {
   3438 	vd_dring_entry_t *dep = NULL;		/* Dring Entry Pointer */
   3439 	vdc_local_desc_t *ldep = NULL;		/* Local Dring Entry Pointer */
   3440 	int		status = ENXIO;
   3441 	int		rv = 0;
   3442 
   3443 	ASSERT(vdc != NULL);
   3444 	ASSERT(idx < vdc->dring_len);
   3445 	ldep = &vdc->local_dring[idx];
   3446 	ASSERT(ldep != NULL);
   3447 	ASSERT(MUTEX_HELD(&vdc->lock));
   3448 
   3449 	DTRACE_PROBE2(depopulate, int, vdc->instance, vdc_local_desc_t *, ldep);
   3450 	DMSG(vdc, 2, ": idx = %d\n", idx);
   3451 
   3452 	dep = ldep->dep;
   3453 	ASSERT(dep != NULL);
   3454 	ASSERT((dep->hdr.dstate == VIO_DESC_DONE) ||
   3455 	    (dep->payload.status == ECANCELED));
   3456 
   3457 	VDC_MARK_DRING_ENTRY_FREE(vdc, idx);
   3458 
   3459 	ldep->is_free = B_TRUE;
   3460 	status = dep->payload.status;
   3461 	DMSG(vdc, 2, ": is_free = %d : status = %d\n", ldep->is_free, status);
   3462 
   3463 	/*
   3464 	 * If no buffers were used to transfer information to the server when
   3465 	 * populating the descriptor then no memory handles need to be unbound
   3466 	 * and we can return now.
   3467 	 */
   3468 	if (ldep->nbytes == 0) {
   3469 		cv_signal(&vdc->dring_free_cv);
   3470 		return (status);
   3471 	}
   3472 
   3473 	/*
   3474 	 * If the upper layer passed in a misaligned address we copied the
   3475 	 * data into an aligned buffer before sending it to LDC - we now
   3476 	 * copy it back to the original buffer.
   3477 	 */
   3478 	if (ldep->align_addr) {
   3479 		ASSERT(ldep->addr != NULL);
   3480 
   3481 		if (dep->payload.nbytes > 0)
   3482 			bcopy(ldep->align_addr, ldep->addr,
   3483 			    dep->payload.nbytes);
   3484 		kmem_free(ldep->align_addr,
   3485 		    sizeof (caddr_t) * P2ROUNDUP(ldep->nbytes, 8));
   3486 		ldep->align_addr = NULL;
   3487 	}
   3488 
   3489 	rv = ldc_mem_unbind_handle(ldep->desc_mhdl);
   3490 	if (rv != 0) {
   3491 		DMSG(vdc, 0, "?[%d] unbind mhdl 0x%lx @ idx %d failed (%d)",
   3492 		    vdc->instance, ldep->desc_mhdl, idx, rv);
   3493 		/*
   3494 		 * The error returned by the vDisk server is more informative
   3495 		 * and thus has a higher priority but if it isn't set we ensure
   3496 		 * that this function returns an error.
   3497 		 */
   3498 		if (status == 0)
   3499 			status = EINVAL;
   3500 	}
   3501 
   3502 	cv_signal(&vdc->membind_cv);
   3503 	cv_signal(&vdc->dring_free_cv);
   3504 
   3505 	return (status);
   3506 }
   3507 
   3508 /*
   3509  * Function:
   3510  *	vdc_populate_mem_hdl()
   3511  *
   3512  * Description:
   3513  *
   3514  * Arguments:
   3515  *	vdc	- soft state pointer for this instance of the device driver.
   3516  *	idx	- Index of the Descriptor Ring entry being modified
   3517  *	addr	- virtual address being mapped in
   3518  *	nybtes	- number of bytes in 'addr'
   3519  *	operation - the vDisk operation being performed (VD_OP_xxx)
   3520  *
   3521  * Return Code:
   3522  *	0	- Success
   3523  */
   3524 static int
   3525 vdc_populate_mem_hdl(vdc_t *vdcp, vdc_local_desc_t *ldep)
   3526 {
   3527 	vd_dring_entry_t	*dep = NULL;
   3528 	ldc_mem_handle_t	mhdl;
   3529 	caddr_t			vaddr;
   3530 	size_t			nbytes;
   3531 	uint8_t			perm = LDC_MEM_RW;
   3532 	uint8_t			maptype;
   3533 	int			rv = 0;
   3534 	int			i;
   3535 
   3536 	ASSERT(vdcp != NULL);
   3537 
   3538 	dep = ldep->dep;
   3539 	mhdl = ldep->desc_mhdl;
   3540 
   3541 	switch (ldep->dir) {
   3542 	case VIO_read_dir:
   3543 		perm = LDC_MEM_W;
   3544 		break;
   3545 
   3546 	case VIO_write_dir:
   3547 		perm = LDC_MEM_R;
   3548 		break;
   3549 
   3550 	case VIO_both_dir:
   3551 		perm = LDC_MEM_RW;
   3552 		break;
   3553 
   3554 	default:
   3555 		ASSERT(0);	/* catch bad programming in vdc */
   3556 	}
   3557 
   3558 	/*
   3559 	 * LDC expects any addresses passed in to be 8-byte aligned. We need
   3560 	 * to copy the contents of any misaligned buffers to a newly allocated
   3561 	 * buffer and bind it instead (and copy the the contents back to the
   3562 	 * original buffer passed in when depopulating the descriptor)
   3563 	 */
   3564 	vaddr = ldep->addr;
   3565 	nbytes = ldep->nbytes;
   3566 	if (((uint64_t)vaddr & 0x7) != 0) {
   3567 		ASSERT(ldep->align_addr == NULL);
   3568 		ldep->align_addr =
   3569 		    kmem_alloc(sizeof (caddr_t) *
   3570 		    P2ROUNDUP(nbytes, 8), KM_SLEEP);
   3571 		DMSG(vdcp, 0, "[%d] Misaligned address %p reallocating "
   3572 		    "(buf=%p nb=%ld op=%d)\n",
   3573 		    vdcp->instance, (void *)vaddr, (void *)ldep->align_addr,
   3574 		    nbytes, ldep->operation);
   3575 		if (perm != LDC_MEM_W)
   3576 			bcopy(vaddr, ldep->align_addr, nbytes);
   3577 		vaddr = ldep->align_addr;
   3578 	}
   3579 
   3580 	maptype = LDC_IO_MAP|LDC_SHADOW_MAP|LDC_DIRECT_MAP;
   3581 	rv = ldc_mem_bind_handle(mhdl, vaddr, P2ROUNDUP(nbytes, 8),
   3582 	    maptype, perm, &dep->payload.cookie[0], &dep->payload.ncookies);
   3583 	DMSG(vdcp, 2, "[%d] bound mem handle; ncookies=%d\n",
   3584 	    vdcp->instance, dep->payload.ncookies);
   3585 	if (rv != 0) {
   3586 		DMSG(vdcp, 0, "[%d] Failed to bind LDC memory handle "
   3587 		    "(mhdl=%p, buf=%p, err=%d)\n",
   3588 		    vdcp->instance, (void *)mhdl, (void *)vaddr, rv);
   3589 		if (ldep->align_addr) {
   3590 			kmem_free(ldep->align_addr,
   3591 			    sizeof (caddr_t) * P2ROUNDUP(nbytes, 8));
   3592 			ldep->align_addr = NULL;
   3593 		}
   3594 		return (EAGAIN);
   3595 	}
   3596 
   3597 	/*
   3598 	 * Get the other cookies (if any).
   3599 	 */
   3600 	for (i = 1; i < dep->payload.ncookies; i++) {
   3601 		rv = ldc_mem_nextcookie(mhdl, &dep->payload.cookie[i]);
   3602 		if (rv != 0) {
   3603 			(void) ldc_mem_unbind_handle(mhdl);
   3604 			DMSG(vdcp, 0, "?[%d] Failed to get next cookie "
   3605 			    "(mhdl=%lx cnum=%d), err=%d",
   3606 			    vdcp->instance, mhdl, i, rv);
   3607 			if (ldep->align_addr) {
   3608 				kmem_free(ldep->align_addr,
   3609 				    sizeof (caddr_t) * ldep->nbytes);
   3610 				ldep->align_addr = NULL;
   3611 			}
   3612 			return (EAGAIN);
   3613 		}
   3614 	}
   3615 
   3616 	return (rv);
   3617 }
   3618 
   3619 /*
   3620  * Interrupt handlers for messages from LDC
   3621  */
   3622 
   3623 /*
   3624  * Function:
   3625  *	vdc_handle_cb()
   3626  *
   3627  * Description:
   3628  *
   3629  * Arguments:
   3630  *	event	- Type of event (LDC_EVT_xxx) that triggered the callback
   3631  *	arg	- soft state pointer for this instance of the device driver.
   3632  *
   3633  * Return Code:
   3634  *	0	- Success
   3635  */
   3636 static uint_t
   3637 vdc_handle_cb(uint64_t event, caddr_t arg)
   3638 {
   3639 	ldc_status_t	ldc_state;
   3640 	int		rv = 0;
   3641 	vdc_server_t	*srvr = (vdc_server_t *)(void *)arg;
   3642 	vdc_t		*vdc = srvr->vdcp;
   3643 
   3644 	ASSERT(vdc != NULL);
   3645 
   3646 	DMSG(vdc, 1, "evt=%lx seqID=%ld\n", event, vdc->seq_num);
   3647 
   3648 	/* If callback is not for the current server, ignore it */
   3649 	mutex_enter(&vdc->lock);
   3650 
   3651 	if (vdc->curr_server != srvr) {
   3652 		DMSG(vdc, 0, "[%d] Ignoring event 0x%lx for port@%ld\n",
   3653 		    vdc->instance, event, srvr->id);
   3654 		mutex_exit(&vdc->lock);
   3655 		return (LDC_SUCCESS);
   3656 	}
   3657 
   3658 	/*
   3659 	 * Depending on the type of event that triggered this callback,
   3660 	 * we modify the handshake state or read the data.
   3661 	 *
   3662 	 * NOTE: not done as a switch() as event could be triggered by
   3663 	 * a state change and a read request. Also the ordering	of the
   3664 	 * check for the event types is deliberate.
   3665 	 */
   3666 	if (event & LDC_EVT_UP) {
   3667 		DMSG(vdc, 0, "[%d] Received LDC_EVT_UP\n", vdc->instance);
   3668 
   3669 		/* get LDC state */
   3670 		rv = ldc_status(srvr->ldc_handle, &ldc_state);
   3671 		if (rv != 0) {
   3672 			DMSG(vdc, 0, "[%d] Couldn't get LDC status %d",
   3673 			    vdc->instance, rv);
   3674 			mutex_exit(&vdc->lock);
   3675 			return (LDC_SUCCESS);
   3676 		}
   3677 		if (srvr->ldc_state != LDC_UP &&
   3678 		    ldc_state == LDC_UP) {
   3679 			/*
   3680 			 * Reset the transaction sequence numbers when
   3681 			 * LDC comes up. We then kick off the handshake
   3682 			 * negotiation with the vDisk server.
   3683 			 */
   3684 			vdc->seq_num = 1;
   3685 			vdc->seq_num_reply = 0;
   3686 			srvr->ldc_state = ldc_state;
   3687 			cv_signal(&vdc->initwait_cv);
   3688 		}
   3689 	}
   3690 
   3691 	if (event & LDC_EVT_READ) {
   3692 		DMSG(vdc, 1, "[%d] Received LDC_EVT_READ\n", vdc->instance);
   3693 		mutex_enter(&vdc->read_lock);
   3694 		cv_signal(&vdc->read_cv);
   3695 		vdc->read_state = VDC_READ_PENDING;
   3696 		mutex_exit(&vdc->read_lock);
   3697 		mutex_exit(&vdc->lock);
   3698 
   3699 		/* that's all we have to do - no need to handle DOWN/RESET */
   3700 		return (LDC_SUCCESS);
   3701 	}
   3702 
   3703 	if (event & (LDC_EVT_RESET|LDC_EVT_DOWN)) {
   3704 
   3705 		DMSG(vdc, 0, "[%d] Received LDC RESET event\n", vdc->instance);
   3706 
   3707 		/*
   3708 		 * Need to wake up any readers so they will
   3709 		 * detect that a reset has occurred.
   3710 		 */
   3711 		mutex_enter(&vdc->read_lock);
   3712 		if ((vdc->read_state == VDC_READ_WAITING) ||
   3713 		    (vdc->read_state == VDC_READ_RESET))
   3714 			cv_signal(&vdc->read_cv);
   3715 		vdc->read_state = VDC_READ_RESET;
   3716 		mutex_exit(&vdc->read_lock);
   3717 
   3718 		/* wake up any threads waiting for connection to come up */
   3719 		if (vdc->state == VDC_STATE_INIT_WAITING) {
   3720 			vdc->state = VDC_STATE_RESETTING;
   3721 			cv_signal(&vdc->initwait_cv);
   3722 		}
   3723 
   3724 	}
   3725 
   3726 	mutex_exit(&vdc->lock);
   3727 
   3728 	if (event & ~(LDC_EVT_UP | LDC_EVT_RESET | LDC_EVT_DOWN | LDC_EVT_READ))
   3729 		DMSG(vdc, 0, "![%d] Unexpected LDC event (%lx) received",
   3730 		    vdc->instance, event);
   3731 
   3732 	return (LDC_SUCCESS);
   3733 }
   3734 
   3735 /*
   3736  * Function:
   3737  *	vdc_wait_for_response()
   3738  *
   3739  * Description:
   3740  *	Block waiting for a response from the server. If there is
   3741  *	no data the thread block on the read_cv that is signalled
   3742  *	by the callback when an EVT_READ occurs.
   3743  *
   3744  * Arguments:
   3745  *	vdcp	- soft state pointer for this instance of the device driver.
   3746  *
   3747  * Return Code:
   3748  *	0	- Success
   3749  */
   3750 static int
   3751 vdc_wait_for_response(vdc_t *vdcp, vio_msg_t *msgp)
   3752 {
   3753 	size_t		nbytes = sizeof (*msgp);
   3754 	int		status;
   3755 
   3756 	ASSERT(vdcp != NULL);
   3757 
   3758 	DMSG(vdcp, 1, "[%d] Entered\n", vdcp->instance);
   3759 
   3760 	status = vdc_recv(vdcp, msgp, &nbytes);
   3761 	DMSG(vdcp, 3, "vdc_read() done.. status=0x%x size=0x%x\n",
   3762 	    status, (int)nbytes);
   3763 	if (status) {
   3764 		DMSG(vdcp, 0, "?[%d] Error %d reading LDC msg\n",
   3765 		    vdcp->instance, status);
   3766 		return (status);
   3767 	}
   3768 
   3769 	if (nbytes < sizeof (vio_msg_tag_t)) {
   3770 		DMSG(vdcp, 0, "?[%d] Expect %lu bytes; recv'd %lu\n",
   3771 		    vdcp->instance, sizeof (vio_msg_tag_t), nbytes);
   3772 		return (ENOMSG);
   3773 	}
   3774 
   3775 	DMSG(vdcp, 2, "[%d] (%x/%x/%x)\n", vdcp->instance,
   3776 	    msgp->tag.vio_msgtype,
   3777 	    msgp->tag.vio_subtype,
   3778 	    msgp->tag.vio_subtype_env);
   3779 
   3780 	/*
   3781 	 * Verify the Session ID of the message
   3782 	 *
   3783 	 * Every message after the Version has been negotiated should
   3784 	 * have the correct session ID set.
   3785 	 */
   3786 	if ((msgp->tag.vio_sid != vdcp->session_id) &&
   3787 	    (msgp->tag.vio_subtype_env != VIO_VER_INFO)) {
   3788 		DMSG(vdcp, 0, "[%d] Invalid SID: received 0x%x, "
   3789 		    "expected 0x%lx [seq num %lx @ %d]",
   3790 		    vdcp->instance, msgp->tag.vio_sid,
   3791 		    vdcp->session_id,
   3792 		    ((vio_dring_msg_t *)msgp)->seq_num,
   3793 		    ((vio_dring_msg_t *)msgp)->start_idx);
   3794 		return (ENOMSG);
   3795 	}
   3796 	return (0);
   3797 }
   3798 
   3799 
   3800 /*
   3801  * Function:
   3802  *	vdc_resubmit_backup_dring()
   3803  *
   3804  * Description:
   3805  *	Resubmit each descriptor in the backed up dring to
   3806  * 	vDisk server. The Dring was backed up during connection
   3807  *	reset.
   3808  *
   3809  * Arguments:
   3810  *	vdcp	- soft state pointer for this instance of the device driver.
   3811  *
   3812  * Return Code:
   3813  *	0	- Success
   3814  */
   3815 static int
   3816 vdc_resubmit_backup_dring(vdc_t *vdcp)
   3817 {
   3818 	int		processed = 0;
   3819 	int		count;
   3820 	int		b_idx;
   3821 	int		rv = 0;
   3822 	int		dring_size;
   3823 	int		op;
   3824 	vio_msg_t	vio_msg;
   3825 	vdc_local_desc_t	*curr_ldep;
   3826 
   3827 	ASSERT(MUTEX_NOT_HELD(&vdcp->lock));
   3828 	ASSERT(vdcp->state == VDC_STATE_HANDLE_PENDING);
   3829 
   3830 	if (vdcp->local_dring_backup == NULL) {
   3831 		/* the pending requests have already been processed */
   3832 		return (0);
   3833 	}
   3834 
   3835 	DMSG(vdcp, 1, "restoring pending dring entries (len=%d, tail=%d)\n",
   3836 	    vdcp->local_dring_backup_len, vdcp->local_dring_backup_tail);
   3837 
   3838 	/*
   3839 	 * Walk the backup copy of the local descriptor ring and
   3840 	 * resubmit all the outstanding transactions.
   3841 	 */
   3842 	b_idx = vdcp->local_dring_backup_tail;
   3843 	for (count = 0; count < vdcp->local_dring_backup_len; count++) {
   3844 
   3845 		curr_ldep = &(vdcp->local_dring_backup[b_idx]);
   3846 
   3847 		/* only resubmit outstanding transactions */
   3848 		if (!curr_ldep->is_free) {
   3849 			/*
   3850 			 * If we are retrying a block read/write operation we
   3851 			 * need to update the I/O statistics to indicate that
   3852 			 * the request is being put back on the waitq to be
   3853 			 * serviced (it will have been taken off after the
   3854 			 * error was reported).
   3855 			 */
   3856 			mutex_enter(&vdcp->lock);
   3857 			op = curr_ldep->operation;
   3858 			if ((op == VD_OP_BREAD) || (op == VD_OP_BWRITE)) {
   3859 				DTRACE_IO1(start, buf_t *, curr_ldep->cb_arg);
   3860 				VD_KSTAT_WAITQ_ENTER(vdcp);
   3861 			}
   3862 
   3863 			DMSG(vdcp, 1, "resubmitting entry idx=%x\n", b_idx);
   3864 			rv = vdc_populate_descriptor(vdcp, op,
   3865 			    curr_ldep->addr, curr_ldep->nbytes,
   3866 			    curr_ldep->slice, curr_ldep->offset,
   3867 			    curr_ldep->cb_type, curr_ldep->cb_arg,
   3868 			    curr_ldep->dir);
   3869 
   3870 			if (rv) {
   3871 				if (op == VD_OP_BREAD || op == VD_OP_BWRITE) {
   3872 					VD_UPDATE_ERR_STATS(vdcp, vd_transerrs);
   3873 					VD_KSTAT_WAITQ_EXIT(vdcp);
   3874 					DTRACE_IO1(done, buf_t *,
   3875 					    curr_ldep->cb_arg);
   3876 				}
   3877 				DMSG(vdcp, 1, "[%d] cannot resubmit entry %d\n",
   3878 				    vdcp->instance, b_idx);
   3879 				mutex_exit(&vdcp->lock);
   3880 				goto done;
   3881 			}
   3882 
   3883 			/*
   3884 			 * If this is a block read/write we update the I/O
   3885 			 * statistics kstat to indicate that the request
   3886 			 * has been sent back to the vDisk server and should
   3887 			 * now be put on the run queue.
   3888 			 */
   3889 			if ((op == VD_OP_BREAD) || (op == VD_OP_BWRITE)) {
   3890 				DTRACE_PROBE1(send, buf_t *, curr_ldep->cb_arg);
   3891 				VD_KSTAT_WAITQ_TO_RUNQ(vdcp);
   3892 			}
   3893 			mutex_exit(&vdcp->lock);
   3894 
   3895 			/* Wait for the response message. */
   3896 			DMSG(vdcp, 1, "waiting for response to idx=%x\n",
   3897 			    b_idx);
   3898 			rv = vdc_wait_for_response(vdcp, &vio_msg);
   3899 			if (rv) {
   3900 				/*
   3901 				 * If this is a block read/write we update
   3902 				 * the I/O statistics kstat to take it
   3903 				 * off the run queue.
   3904 				 */
   3905 				mutex_enter(&vdcp->lock);
   3906 				if (op == VD_OP_BREAD || op == VD_OP_BWRITE) {
   3907 					VD_UPDATE_ERR_STATS(vdcp, vd_transerrs);
   3908 					VD_KSTAT_RUNQ_EXIT(vdcp);
   3909 					DTRACE_IO1(done, buf_t *,
   3910 					    curr_ldep->cb_arg);
   3911 				}
   3912 				DMSG(vdcp, 1, "[%d] wait_for_response "
   3913 				    "returned err=%d\n", vdcp->instance,
   3914 				    rv);
   3915 				mutex_exit(&vdcp->lock);
   3916 				goto done;
   3917 			}
   3918 
   3919 			DMSG(vdcp, 1, "processing msg for idx=%x\n", b_idx);
   3920 			rv = vdc_process_data_msg(vdcp, &vio_msg);
   3921 			if (rv) {
   3922 				DMSG(vdcp, 1, "[%d] process_data_msg "
   3923 				    "returned err=%d\n", vdcp->instance,
   3924 				    rv);
   3925 				goto done;
   3926 			}
   3927 			/*
   3928 			 * Mark this entry as free so that we will not resubmit
   3929 			 * this "done" request again, if we were to use the same
   3930 			 * backup_dring again in future. This could happen when
   3931 			 * a reset happens while processing the backup_dring.
   3932 			 */
   3933 			curr_ldep->is_free = B_TRUE;
   3934 			processed++;
   3935 		}
   3936 
   3937 		/* get the next element to submit */
   3938 		if (++b_idx >= vdcp->local_dring_backup_len)
   3939 			b_idx = 0;
   3940 	}
   3941 
   3942 	/* all done - now clear up pending dring copy */
   3943 	dring_size = vdcp->local_dring_backup_len *
   3944 	    sizeof (vdcp->local_dring_backup[0]);
   3945 
   3946 	(void) kmem_free(vdcp->local_dring_backup, dring_size);
   3947 
   3948 	vdcp->local_dring_backup = NULL;
   3949 
   3950 done:
   3951 	DTRACE_PROBE2(processed, int, processed, vdc_t *, vdcp);
   3952 
   3953 	return (rv);
   3954 }
   3955 
   3956 /*
   3957  * Function:
   3958  *	vdc_cancel_backup_dring
   3959  *
   3960  * Description:
   3961  *	Cancel each descriptor in the backed up dring to vDisk server.
   3962  *	The Dring was backed up during connection reset.
   3963  *
   3964  * Arguments:
   3965  *	vdcp	- soft state pointer for this instance of the device driver.
   3966  *
   3967  * Return Code:
   3968  *	None
   3969  */
   3970 void
   3971 vdc_cancel_backup_dring(vdc_t *vdcp)
   3972 {
   3973 	vdc_local_desc_t *ldep;
   3974 	struct buf 	*bufp;
   3975 	int		count;
   3976 	int		b_idx;
   3977 	int		dring_size;
   3978 	int		cancelled = 0;
   3979 
   3980 	ASSERT(MUTEX_HELD(&vdcp->lock));
   3981 	ASSERT(vdcp->state == VDC_STATE_INIT ||
   3982 	    vdcp->state == VDC_STATE_INIT_WAITING ||
   3983 	    vdcp->state == VDC_STATE_NEGOTIATE ||
   3984 	    vdcp->state == VDC_STATE_RESETTING);
   3985 
   3986 	if (vdcp->local_dring_backup == NULL) {
   3987 		/* the pending requests have already been processed */
   3988 		return;
   3989 	}
   3990 
   3991 	DMSG(vdcp, 1, "cancelling pending dring entries (len=%d, tail=%d)\n",
   3992 	    vdcp->local_dring_backup_len, vdcp->local_dring_backup_tail);
   3993 
   3994 	/*
   3995 	 * Walk the backup copy of the local descriptor ring and
   3996 	 * cancel all the outstanding transactions.
   3997 	 */
   3998 	b_idx = vdcp->local_dring_backup_tail;
   3999 	for (count = 0; count < vdcp->local_dring_backup_len; count++) {
   4000 
   4001 		ldep = &(vdcp->local_dring_backup[b_idx]);
   4002 
   4003 		/* only cancel outstanding transactions */
   4004 		if (!ldep->is_free) {
   4005 
   4006 			DMSG(vdcp, 1, "cancelling entry idx=%x\n", b_idx);
   4007 			cancelled++;
   4008 
   4009 			/*
   4010 			 * All requests have already been cleared from the
   4011 			 * local descriptor ring and the LDC channel has been
   4012 			 * reset so we will never get any reply for these
   4013 			 * requests. Now we just have to notify threads waiting
   4014 			 * for replies that the request has failed.
   4015 			 */
   4016 			switch (ldep->cb_type) {
   4017 			case CB_SYNC:
   4018 				ASSERT(vdcp->sync_op_pending);
   4019 				vdcp->sync_op_status = EIO;
   4020 				vdcp->sync_op_pending = B_FALSE;
   4021 				cv_signal(&vdcp->sync_pending_cv);
   4022 				break;
   4023 
   4024 			case CB_STRATEGY:
   4025 				bufp = ldep->cb_arg;
   4026 				ASSERT(bufp != NULL);
   4027 				bufp->b_resid = bufp->b_bcount;