xref: /freebsd/sys/powerpc/pseries/phyp_vscsi.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*-
2  * Copyright 2013 Nathan Whitehorn
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 #include <sys/selinfo.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/eventhandler.h>
39 #include <sys/rman.h>
40 #include <sys/bus_dma.h>
41 #include <sys/bio.h>
42 #include <sys/ioccom.h>
43 #include <sys/uio.h>
44 #include <sys/proc.h>
45 #include <sys/signalvar.h>
46 #include <sys/sysctl.h>
47 #include <sys/endian.h>
48 #include <sys/vmem.h>
49 
50 #include <cam/cam.h>
51 #include <cam/cam_ccb.h>
52 #include <cam/cam_debug.h>
53 #include <cam/cam_periph.h>
54 #include <cam/cam_sim.h>
55 #include <cam/cam_xpt_periph.h>
56 #include <cam/cam_xpt_sim.h>
57 #include <cam/scsi/scsi_all.h>
58 #include <cam/scsi/scsi_message.h>
59 
60 #include <dev/ofw/openfirm.h>
61 #include <dev/ofw/ofw_bus.h>
62 #include <dev/ofw/ofw_bus_subr.h>
63 
64 #include <machine/bus.h>
65 #include <machine/resource.h>
66 
67 #include <powerpc/pseries/phyp-hvcall.h>
68 
69 struct vscsi_softc;
70 
71 /* VSCSI CRQ format from table 260 of PAPR spec 2.4 (page 760) */
72 struct vscsi_crq {
73 	uint8_t valid;
74 	uint8_t format;
75 	uint8_t reserved;
76 	uint8_t status;
77 	uint16_t timeout;
78 	uint16_t iu_length;
79 	uint64_t iu_data;
80 };
81 
82 struct vscsi_xfer {
83         TAILQ_ENTRY(vscsi_xfer) queue;
84         struct vscsi_softc *sc;
85         union ccb *ccb;
86         bus_dmamap_t dmamap;
87         uint64_t tag;
88 
89 	vmem_addr_t srp_iu_offset;
90 	vmem_size_t srp_iu_size;
91 };
92 
93 TAILQ_HEAD(vscsi_xferq, vscsi_xfer);
94 
95 struct vscsi_softc {
96 	device_t	dev;
97 	struct cam_devq *devq;
98 	struct cam_sim	*sim;
99 	struct cam_path	*path;
100 	struct mtx io_lock;
101 
102 	cell_t		unit;
103 	int		bus_initialized;
104 	int		bus_logged_in;
105 	int		max_transactions;
106 
107 	int		irqid;
108 	struct resource	*irq;
109 	void		*irq_cookie;
110 
111 	bus_dma_tag_t	crq_tag;
112 	struct vscsi_crq *crq_queue;
113 	int		n_crqs, cur_crq;
114 	bus_dmamap_t	crq_map;
115 	bus_addr_t	crq_phys;
116 
117 	vmem_t		*srp_iu_arena;
118 	void		*srp_iu_queue;
119 	bus_addr_t	srp_iu_phys;
120 
121 	bus_dma_tag_t	data_tag;
122 
123 	struct vscsi_xfer loginxp;
124 	struct vscsi_xfer *xfer;
125 	struct vscsi_xferq active_xferq;
126 	struct vscsi_xferq free_xferq;
127 };
128 
129 struct srp_login {
130 	uint8_t type;
131 	uint8_t reserved[7];
132 	uint64_t tag;
133 	uint64_t max_cmd_length;
134 	uint32_t reserved2;
135 	uint16_t buffer_formats;
136 	uint8_t flags;
137 	uint8_t reserved3[5];
138 	uint8_t initiator_port_id[16];
139 	uint8_t target_port_id[16];
140 } __packed;
141 
142 struct srp_login_rsp {
143 	uint8_t type;
144 	uint8_t reserved[3];
145 	uint32_t request_limit_delta;
146 	uint8_t tag;
147 	uint32_t max_i_to_t_len;
148 	uint32_t max_t_to_i_len;
149 	uint16_t buffer_formats;
150 	uint8_t flags;
151 	/* Some reserved bits follow */
152 } __packed;
153 
154 struct srp_cmd {
155 	uint8_t type;
156 	uint8_t flags1;
157 	uint8_t reserved[3];
158 	uint8_t formats;
159 	uint8_t out_buffer_count;
160 	uint8_t in_buffer_count;
161 	uint64_t tag;
162 	uint32_t reserved2;
163 	uint64_t lun;
164 	uint8_t reserved3[3];
165 	uint8_t additional_cdb;
166 	uint8_t cdb[16];
167 	uint8_t data_payload[0];
168 } __packed;
169 
170 struct srp_rsp {
171 	uint8_t type;
172 	uint8_t reserved[3];
173 	uint32_t request_limit_delta;
174 	uint64_t tag;
175 	uint16_t reserved2;
176 	uint8_t flags;
177 	uint8_t status;
178 	uint32_t data_out_resid;
179 	uint32_t data_in_resid;
180 	uint32_t sense_data_len;
181 	uint32_t response_data_len;
182 	uint8_t data_payload[0];
183 } __packed;
184 
185 struct srp_tsk_mgmt {
186 	uint8_t type;
187 	uint8_t reserved[7];
188 	uint64_t tag;
189 	uint32_t reserved2;
190 	uint64_t lun;
191 	uint8_t reserved3[2];
192 	uint8_t function;
193 	uint8_t reserved4;
194 	uint64_t manage_tag;
195 	uint64_t reserved5;
196 } __packed;
197 
198 /* Message code type */
199 #define SRP_LOGIN_REQ	0x00
200 #define SRP_TSK_MGMT	0x01
201 #define SRP_CMD		0x02
202 #define SRP_I_LOGOUT	0x03
203 
204 #define SRP_LOGIN_RSP	0xC0
205 #define SRP_RSP		0xC1
206 #define SRP_LOGIN_REJ	0xC2
207 
208 #define SRP_T_LOGOUT	0x80
209 #define SRP_CRED_REQ	0x81
210 #define SRP_AER_REQ	0x82
211 
212 #define SRP_CRED_RSP	0x41
213 #define SRP_AER_RSP	0x41
214 
215 /* Flags for srp_rsp flags field */
216 #define SRP_RSPVALID	0x01
217 #define SRP_SNSVALID	0x02
218 #define SRP_DOOVER	0x04
219 #define SRP_DOUNDER	0x08
220 #define SRP_DIOVER	0x10
221 #define SRP_DIUNDER	0x20
222 
223 #define	MAD_SUCESS			0x00
224 #define	MAD_NOT_SUPPORTED		0xf1
225 #define	MAD_FAILED			0xf7
226 
227 #define	MAD_EMPTY_IU			0x01
228 #define	MAD_ERROR_LOGGING_REQUEST	0x02
229 #define	MAD_ADAPTER_INFO_REQUEST	0x03
230 #define	MAD_CAPABILITIES_EXCHANGE	0x05
231 #define	MAD_PHYS_ADAP_INFO_REQUEST	0x06
232 #define	MAD_TAPE_PASSTHROUGH_REQUEST	0x07
233 #define	MAD_ENABLE_FAST_FAIL		0x08
234 
235 static int	vscsi_probe(device_t);
236 static int	vscsi_attach(device_t);
237 static int	vscsi_detach(device_t);
238 static void	vscsi_cam_action(struct cam_sim *, union ccb *);
239 static void	vscsi_cam_poll(struct cam_sim *);
240 static void	vscsi_intr(void *arg);
241 static void	vscsi_check_response_queue(struct vscsi_softc *sc);
242 static void	vscsi_setup_bus(struct vscsi_softc *sc);
243 
244 static void	vscsi_srp_login(struct vscsi_softc *sc);
245 static void	vscsi_crq_load_cb(void *, bus_dma_segment_t *, int, int);
246 static void	vscsi_scsi_command(void *xxp, bus_dma_segment_t *segs,
247 		    int nsegs, int err);
248 static void	vscsi_task_management(struct vscsi_softc *sc, union ccb *ccb);
249 static void	vscsi_srp_response(struct vscsi_xfer *, struct vscsi_crq *);
250 
251 static devclass_t	vscsi_devclass;
252 static device_method_t	vscsi_methods[] = {
253 	DEVMETHOD(device_probe,		vscsi_probe),
254 	DEVMETHOD(device_attach,	vscsi_attach),
255 	DEVMETHOD(device_detach,	vscsi_detach),
256 
257 	DEVMETHOD_END
258 };
259 static driver_t vscsi_driver = {
260 	"vscsi",
261 	vscsi_methods,
262 	sizeof(struct vscsi_softc)
263 };
264 DRIVER_MODULE(vscsi, vdevice, vscsi_driver, vscsi_devclass, 0, 0);
265 MALLOC_DEFINE(M_VSCSI, "vscsi", "CAM device queue for VSCSI");
266 
267 static int
268 vscsi_probe(device_t dev)
269 {
270 
271 	if (!ofw_bus_is_compatible(dev, "IBM,v-scsi"))
272 		return (ENXIO);
273 
274 	device_set_desc(dev, "POWER Hypervisor Virtual SCSI Bus");
275 	return (0);
276 }
277 
278 static int
279 vscsi_attach(device_t dev)
280 {
281 	struct vscsi_softc *sc;
282 	struct vscsi_xfer *xp;
283 	int error, i;
284 
285 	sc = device_get_softc(dev);
286 	if (sc == NULL)
287 		return (EINVAL);
288 
289 	sc->dev = dev;
290 	mtx_init(&sc->io_lock, "vscsi", NULL, MTX_DEF);
291 
292 	/* Get properties */
293 	OF_getprop(ofw_bus_get_node(dev), "reg", &sc->unit, sizeof(sc->unit));
294 
295 	/* Setup interrupt */
296 	sc->irqid = 0;
297 	sc->irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->irqid,
298 	    RF_ACTIVE);
299 
300 	if (!sc->irq) {
301 		device_printf(dev, "Could not allocate IRQ\n");
302 		mtx_destroy(&sc->io_lock);
303 		return (ENXIO);
304 	}
305 
306 	bus_setup_intr(dev, sc->irq, INTR_TYPE_CAM | INTR_MPSAFE |
307 	    INTR_ENTROPY, NULL, vscsi_intr, sc, &sc->irq_cookie);
308 
309 	/* Data DMA */
310 	error = bus_dma_tag_create(bus_get_dma_tag(dev), 1, 0,
311 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, BUS_SPACE_MAXSIZE,
312 	    256, BUS_SPACE_MAXSIZE_32BIT, 0, busdma_lock_mutex, &sc->io_lock,
313 	    &sc->data_tag);
314 
315 	TAILQ_INIT(&sc->active_xferq);
316 	TAILQ_INIT(&sc->free_xferq);
317 
318 	/* First XFER for login data */
319 	sc->loginxp.sc = sc;
320 	bus_dmamap_create(sc->data_tag, 0, &sc->loginxp.dmamap);
321 	TAILQ_INSERT_TAIL(&sc->free_xferq, &sc->loginxp, queue);
322 
323 	/* CRQ area */
324 	error = bus_dma_tag_create(bus_get_dma_tag(dev), PAGE_SIZE, 0,
325 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, 8*PAGE_SIZE,
326 	    1, BUS_SPACE_MAXSIZE, 0, NULL, NULL, &sc->crq_tag);
327 	error = bus_dmamem_alloc(sc->crq_tag, (void **)&sc->crq_queue,
328 	    BUS_DMA_WAITOK | BUS_DMA_ZERO, &sc->crq_map);
329 	sc->crq_phys = 0;
330 	sc->n_crqs = 0;
331 	error = bus_dmamap_load(sc->crq_tag, sc->crq_map, sc->crq_queue,
332 	    8*PAGE_SIZE, vscsi_crq_load_cb, sc, 0);
333 
334 	mtx_lock(&sc->io_lock);
335 	vscsi_setup_bus(sc);
336 	sc->xfer = malloc(sizeof(sc->xfer[0])*sc->max_transactions, M_VSCSI,
337 	    M_NOWAIT);
338 	for (i = 0; i < sc->max_transactions; i++) {
339 		xp = &sc->xfer[i];
340 		xp->sc = sc;
341 
342 		error = bus_dmamap_create(sc->data_tag, 0, &xp->dmamap);
343 		if (error) {
344 			device_printf(dev, "Could not create DMA map (%d)\n",
345 			    error);
346 			break;
347 		}
348 
349 		TAILQ_INSERT_TAIL(&sc->free_xferq, xp, queue);
350 	}
351 	mtx_unlock(&sc->io_lock);
352 
353 	/* Allocate CAM bits */
354 	if ((sc->devq = cam_simq_alloc(sc->max_transactions)) == NULL)
355 		return (ENOMEM);
356 
357 	sc->sim = cam_sim_alloc(vscsi_cam_action, vscsi_cam_poll, "vscsi", sc,
358 				device_get_unit(dev), &sc->io_lock,
359 				sc->max_transactions, sc->max_transactions,
360 				sc->devq);
361 	if (sc->sim == NULL) {
362 		cam_simq_free(sc->devq);
363 		sc->devq = NULL;
364 		device_printf(dev, "CAM SIM attach failed\n");
365 		return (EINVAL);
366 	}
367 
368 
369 	mtx_lock(&sc->io_lock);
370 	if (xpt_bus_register(sc->sim, dev, 0) != 0) {
371 		device_printf(dev, "XPT bus registration failed\n");
372 		cam_sim_free(sc->sim, FALSE);
373 		sc->sim = NULL;
374 		cam_simq_free(sc->devq);
375 		sc->devq = NULL;
376 		mtx_unlock(&sc->io_lock);
377 		return (EINVAL);
378 	}
379 	mtx_unlock(&sc->io_lock);
380 
381 	return (0);
382 }
383 
384 static int
385 vscsi_detach(device_t dev)
386 {
387 	struct vscsi_softc *sc;
388 
389 	sc = device_get_softc(dev);
390 	if (sc == NULL)
391 		return (EINVAL);
392 
393 	if (sc->sim != NULL) {
394 		mtx_lock(&sc->io_lock);
395 		xpt_bus_deregister(cam_sim_path(sc->sim));
396 		cam_sim_free(sc->sim, FALSE);
397 		sc->sim = NULL;
398 		mtx_unlock(&sc->io_lock);
399 	}
400 
401 	if (sc->devq != NULL) {
402 		cam_simq_free(sc->devq);
403 		sc->devq = NULL;
404 	}
405 
406 	mtx_destroy(&sc->io_lock);
407 
408 	return (0);
409 }
410 
411 static void
412 vscsi_cam_action(struct cam_sim *sim, union ccb *ccb)
413 {
414 	struct vscsi_softc *sc = cam_sim_softc(sim);
415 
416 	mtx_assert(&sc->io_lock, MA_OWNED);
417 
418 	switch (ccb->ccb_h.func_code) {
419 	case XPT_PATH_INQ:
420 	{
421 		struct ccb_pathinq *cpi = &ccb->cpi;
422 
423 		cpi->version_num = 1;
424 		cpi->hba_inquiry = PI_TAG_ABLE;
425 		cpi->hba_misc = PIM_EXTLUNS;
426 		cpi->target_sprt = 0;
427 		cpi->hba_eng_cnt = 0;
428 		cpi->max_target = 0;
429 		cpi->max_lun = 0;
430 		cpi->initiator_id = ~0;
431 		strncpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
432 		strncpy(cpi->hba_vid, "IBM", HBA_IDLEN);
433 		strncpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
434 		cpi->unit_number = cam_sim_unit(sim);
435 		cpi->bus_id = cam_sim_bus(sim);
436 		cpi->base_transfer_speed = 150000;
437 		cpi->transport = XPORT_SRP;
438 		cpi->transport_version = 0;
439 		cpi->protocol = PROTO_SCSI;
440 		cpi->protocol_version = SCSI_REV_SPC4;
441 		cpi->ccb_h.status = CAM_REQ_CMP;
442 		break;
443 	}
444 	case XPT_RESET_BUS:
445 		ccb->ccb_h.status = CAM_REQ_CMP;
446 		break;
447 	case XPT_RESET_DEV:
448 		ccb->ccb_h.status = CAM_REQ_INPROG;
449 		vscsi_task_management(sc, ccb);
450 		return;
451 	case XPT_GET_TRAN_SETTINGS:
452 		ccb->cts.protocol = PROTO_SCSI;
453 		ccb->cts.protocol_version = SCSI_REV_SPC4;
454 		ccb->cts.transport = XPORT_SRP;
455 		ccb->cts.transport_version = 0;
456 		ccb->cts.proto_specific.valid = 0;
457 		ccb->cts.xport_specific.valid = 0;
458 		ccb->ccb_h.status = CAM_REQ_CMP;
459 		break;
460 	case XPT_SET_TRAN_SETTINGS:
461 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
462 		break;
463 	case XPT_SCSI_IO:
464 	{
465 		struct vscsi_xfer *xp;
466 
467 		ccb->ccb_h.status = CAM_REQ_INPROG;
468 
469 		xp = TAILQ_FIRST(&sc->free_xferq);
470 		if (xp == NULL)
471 			panic("SCSI queue flooded");
472 		xp->ccb = ccb;
473 		TAILQ_REMOVE(&sc->free_xferq, xp, queue);
474 		TAILQ_INSERT_TAIL(&sc->active_xferq, xp, queue);
475 		bus_dmamap_load_ccb(sc->data_tag, xp->dmamap,
476 		    ccb, vscsi_scsi_command, xp, 0);
477 
478 		return;
479 	}
480 	default:
481 		ccb->ccb_h.status = CAM_REQ_INVALID;
482 		break;
483 	}
484 
485 	xpt_done(ccb);
486 	return;
487 }
488 
489 static void
490 vscsi_srp_login(struct vscsi_softc *sc)
491 {
492 	struct vscsi_xfer *xp;
493 	struct srp_login *login;
494 	struct vscsi_crq crq;
495 	int err;
496 
497 	mtx_assert(&sc->io_lock, MA_OWNED);
498 
499 	xp = TAILQ_FIRST(&sc->free_xferq);
500 	if (xp == NULL)
501 		panic("SCSI queue flooded");
502 	xp->ccb = NULL;
503 	TAILQ_REMOVE(&sc->free_xferq, xp, queue);
504 	TAILQ_INSERT_TAIL(&sc->active_xferq, xp, queue);
505 
506 	/* Set up command */
507 	xp->srp_iu_size = crq.iu_length = 64;
508 	err = vmem_alloc(xp->sc->srp_iu_arena, xp->srp_iu_size,
509 	    M_BESTFIT | M_NOWAIT, &xp->srp_iu_offset);
510 	if (err)
511 		panic("Error during VMEM allocation (%d)", err);
512 
513 	login = (struct srp_login *)((uint8_t *)xp->sc->srp_iu_queue +
514 	    (uintptr_t)xp->srp_iu_offset);
515 	bzero(login, xp->srp_iu_size);
516 	login->type = SRP_LOGIN_REQ;
517 	login->tag = (uint64_t)(xp);
518 	login->max_cmd_length = htobe64(256);
519 	login->buffer_formats = htobe16(0x1 | 0x2); /* Direct and indirect */
520 	login->flags = 0;
521 
522 	/* Create CRQ entry */
523 	crq.valid = 0x80;
524 	crq.format = 0x01;
525 	crq.iu_data = xp->sc->srp_iu_phys + xp->srp_iu_offset;
526 	bus_dmamap_sync(sc->crq_tag, sc->crq_map, BUS_DMASYNC_PREWRITE);
527 
528 	err = phyp_hcall(H_SEND_CRQ, xp->sc->unit, ((uint64_t *)(&crq))[0],
529 	    ((uint64_t *)(&crq))[1]);
530 	if (err != 0)
531 		panic("CRQ send failure (%d)", err);
532 }
533 
534 static void
535 vscsi_task_management(struct vscsi_softc *sc, union ccb *ccb)
536 {
537 	struct srp_tsk_mgmt *cmd;
538 	struct vscsi_xfer *xp;
539 	struct vscsi_crq crq;
540 	int err;
541 
542 	mtx_assert(&sc->io_lock, MA_OWNED);
543 
544 	xp = TAILQ_FIRST(&sc->free_xferq);
545 	if (xp == NULL)
546 		panic("SCSI queue flooded");
547 	xp->ccb = ccb;
548 	TAILQ_REMOVE(&sc->free_xferq, xp, queue);
549 	TAILQ_INSERT_TAIL(&sc->active_xferq, xp, queue);
550 
551 	xp->srp_iu_size = crq.iu_length = sizeof(*cmd);
552 	err = vmem_alloc(xp->sc->srp_iu_arena, xp->srp_iu_size,
553 	    M_BESTFIT | M_NOWAIT, &xp->srp_iu_offset);
554 	if (err)
555 		panic("Error during VMEM allocation (%d)", err);
556 
557 	cmd = (struct srp_tsk_mgmt *)((uint8_t *)xp->sc->srp_iu_queue +
558 	    (uintptr_t)xp->srp_iu_offset);
559 	bzero(cmd, xp->srp_iu_size);
560 	cmd->type = SRP_TSK_MGMT;
561 	cmd->tag = (uint64_t)xp;
562 	cmd->lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
563 
564 	switch (ccb->ccb_h.func_code) {
565 	case XPT_RESET_DEV:
566 		cmd->function = 0x08;
567 		break;
568 	default:
569 		panic("Unimplemented code %d", ccb->ccb_h.func_code);
570 		break;
571 	}
572 
573 	bus_dmamap_sync(xp->sc->crq_tag, xp->sc->crq_map, BUS_DMASYNC_PREWRITE);
574 
575 	/* Create CRQ entry */
576 	crq.valid = 0x80;
577 	crq.format = 0x01;
578 	crq.iu_data = xp->sc->srp_iu_phys + xp->srp_iu_offset;
579 
580 	err = phyp_hcall(H_SEND_CRQ, xp->sc->unit, ((uint64_t *)(&crq))[0],
581 	    ((uint64_t *)(&crq))[1]);
582 	if (err != 0)
583 		panic("CRQ send failure (%d)", err);
584 }
585 
586 static void
587 vscsi_scsi_command(void *xxp, bus_dma_segment_t *segs, int nsegs, int err)
588 {
589 	struct vscsi_xfer *xp = xxp;
590 	uint8_t *cdb;
591 	union ccb *ccb = xp->ccb;
592 	struct srp_cmd *cmd;
593 	uint64_t chunk_addr;
594 	uint32_t chunk_size;
595 	int desc_start, i;
596 	struct vscsi_crq crq;
597 
598 	KASSERT(err == 0, ("DMA error %d\n", err));
599 
600 	mtx_assert(&xp->sc->io_lock, MA_OWNED);
601 
602 	cdb = (ccb->ccb_h.flags & CAM_CDB_POINTER) ?
603 	    ccb->csio.cdb_io.cdb_ptr : ccb->csio.cdb_io.cdb_bytes;
604 
605 	/* Command format from Table 20, page 37 of SRP spec */
606 	crq.iu_length = 48 + ((nsegs > 1) ? 20 : 16) +
607 	    ((ccb->csio.cdb_len > 16) ? (ccb->csio.cdb_len - 16) : 0);
608 	xp->srp_iu_size = crq.iu_length;
609 	if (nsegs > 1)
610 		xp->srp_iu_size += nsegs*16;
611 	xp->srp_iu_size = roundup(xp->srp_iu_size, 16);
612 	err = vmem_alloc(xp->sc->srp_iu_arena, xp->srp_iu_size,
613 	    M_BESTFIT | M_NOWAIT, &xp->srp_iu_offset);
614 	if (err)
615 		panic("Error during VMEM allocation (%d)", err);
616 
617 	cmd = (struct srp_cmd *)((uint8_t *)xp->sc->srp_iu_queue +
618 	    (uintptr_t)xp->srp_iu_offset);
619 	bzero(cmd, xp->srp_iu_size);
620 	cmd->type = SRP_CMD;
621 	if (ccb->csio.cdb_len > 16)
622 		cmd->additional_cdb = (ccb->csio.cdb_len - 16) << 2;
623 	memcpy(cmd->cdb, cdb, ccb->csio.cdb_len);
624 
625 	cmd->tag = (uint64_t)(xp); /* Let the responder find this again */
626 	cmd->lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
627 
628 	if (nsegs > 1) {
629 		/* Use indirect descriptors */
630 		switch (ccb->ccb_h.flags & CAM_DIR_MASK) {
631 		case CAM_DIR_OUT:
632 			cmd->formats = (2 << 4);
633 			break;
634 		case CAM_DIR_IN:
635 			cmd->formats = 2;
636 			break;
637 		default:
638 			panic("Does not support bidirectional commands (%d)",
639 			    ccb->ccb_h.flags & CAM_DIR_MASK);
640 			break;
641 		}
642 
643 		desc_start = ((ccb->csio.cdb_len > 16) ?
644 		    ccb->csio.cdb_len - 16 : 0);
645 		chunk_addr = xp->sc->srp_iu_phys + xp->srp_iu_offset + 20 +
646 		    desc_start + sizeof(*cmd);
647 		chunk_size = 16*nsegs;
648 		memcpy(&cmd->data_payload[desc_start], &chunk_addr, 8);
649 		memcpy(&cmd->data_payload[desc_start+12], &chunk_size, 4);
650 		chunk_size = 0;
651 		for (i = 0; i < nsegs; i++)
652 			chunk_size += segs[i].ds_len;
653 		memcpy(&cmd->data_payload[desc_start+16], &chunk_size, 4);
654 		desc_start += 20;
655 		for (i = 0; i < nsegs; i++) {
656 			chunk_addr = segs[i].ds_addr;
657 			chunk_size = segs[i].ds_len;
658 
659 			memcpy(&cmd->data_payload[desc_start + 16*i],
660 			    &chunk_addr, 8);
661 			/* Set handle tag to 0 */
662 			memcpy(&cmd->data_payload[desc_start + 16*i + 12],
663 			    &chunk_size, 4);
664 		}
665 	} else if (nsegs == 1) {
666 		switch (ccb->ccb_h.flags & CAM_DIR_MASK) {
667 		case CAM_DIR_OUT:
668 			cmd->formats = (1 << 4);
669 			break;
670 		case CAM_DIR_IN:
671 			cmd->formats = 1;
672 			break;
673 		default:
674 			panic("Does not support bidirectional commands (%d)",
675 			    ccb->ccb_h.flags & CAM_DIR_MASK);
676 			break;
677 		}
678 
679 		/*
680 		 * Memory descriptor:
681 		 * 8 byte address
682 		 * 4 byte handle
683 		 * 4 byte length
684 		 */
685 
686 		chunk_addr = segs[0].ds_addr;
687 		chunk_size = segs[0].ds_len;
688 		desc_start = ((ccb->csio.cdb_len > 16) ?
689 		    ccb->csio.cdb_len - 16 : 0);
690 
691 		memcpy(&cmd->data_payload[desc_start], &chunk_addr, 8);
692 		/* Set handle tag to 0 */
693 		memcpy(&cmd->data_payload[desc_start+12], &chunk_size, 4);
694 		KASSERT(xp->srp_iu_size >= 48 + ((ccb->csio.cdb_len > 16) ?
695 		    ccb->csio.cdb_len : 16), ("SRP IU command length"));
696 	} else {
697 		cmd->formats = 0;
698 	}
699 	bus_dmamap_sync(xp->sc->crq_tag, xp->sc->crq_map, BUS_DMASYNC_PREWRITE);
700 
701 	/* Create CRQ entry */
702 	crq.valid = 0x80;
703 	crq.format = 0x01;
704 	crq.iu_data = xp->sc->srp_iu_phys + xp->srp_iu_offset;
705 
706 	err = phyp_hcall(H_SEND_CRQ, xp->sc->unit, ((uint64_t *)(&crq))[0],
707 	    ((uint64_t *)(&crq))[1]);
708 	if (err != 0)
709 		panic("CRQ send failure (%d)", err);
710 }
711 
712 static void
713 vscsi_crq_load_cb(void *xsc, bus_dma_segment_t *segs, int nsegs, int err)
714 {
715 	struct vscsi_softc *sc = xsc;
716 
717 	sc->crq_phys = segs[0].ds_addr;
718 	sc->n_crqs = PAGE_SIZE/sizeof(struct vscsi_crq);
719 
720 	sc->srp_iu_queue = (uint8_t *)(sc->crq_queue);
721 	sc->srp_iu_phys = segs[0].ds_addr;
722 	sc->srp_iu_arena = vmem_create("VSCSI SRP IU", PAGE_SIZE,
723 	    segs[0].ds_len - PAGE_SIZE, 16, 0, M_BESTFIT | M_NOWAIT);
724 }
725 
726 static void
727 vscsi_setup_bus(struct vscsi_softc *sc)
728 {
729 	struct vscsi_crq crq;
730 	struct vscsi_xfer *xp;
731 	int error;
732 
733 	struct {
734 		uint32_t type;
735 		uint16_t status;
736 		uint16_t length;
737 		uint64_t tag;
738 		uint64_t buffer;
739 		struct {
740 			char srp_version[8];
741 			char partition_name[96];
742 			uint32_t partition_number;
743 			uint32_t mad_version;
744 			uint32_t os_type;
745 			uint32_t port_max_txu[8];
746 		} payload;
747 	} mad_adapter_info;
748 
749 	bzero(&crq, sizeof(crq));
750 
751 	/* Init message */
752 	crq.valid = 0xc0;
753 	crq.format = 0x01;
754 
755 	do {
756 		error = phyp_hcall(H_FREE_CRQ, sc->unit);
757 	} while (error == H_BUSY);
758 
759 	/* See initialization sequence page 757 */
760 	bzero(sc->crq_queue, sc->n_crqs*sizeof(sc->crq_queue[0]));
761 	sc->cur_crq = 0;
762 	sc->bus_initialized = 0;
763 	sc->bus_logged_in = 0;
764 	bus_dmamap_sync(sc->crq_tag, sc->crq_map, BUS_DMASYNC_PREWRITE);
765 	error = phyp_hcall(H_REG_CRQ, sc->unit, sc->crq_phys,
766 	    sc->n_crqs*sizeof(sc->crq_queue[0]));
767 	KASSERT(error == 0, ("CRQ registration success"));
768 
769 	error = phyp_hcall(H_SEND_CRQ, sc->unit, ((uint64_t *)(&crq))[0],
770 	    ((uint64_t *)(&crq))[1]);
771 	if (error != 0)
772 		panic("CRQ setup failure (%d)", error);
773 
774 	while (sc->bus_initialized == 0)
775 		vscsi_check_response_queue(sc);
776 
777 	/* Send MAD adapter info */
778 	mad_adapter_info.type = MAD_ADAPTER_INFO_REQUEST;
779 	mad_adapter_info.status = 0;
780 	mad_adapter_info.length = sizeof(mad_adapter_info.payload);
781 
782 	strcpy(mad_adapter_info.payload.srp_version, "16.a");
783 	strcpy(mad_adapter_info.payload.partition_name, "UNKNOWN");
784 	mad_adapter_info.payload.partition_number = -1;
785 	mad_adapter_info.payload.mad_version = 1;
786 	mad_adapter_info.payload.os_type = 2; /* Claim we are Linux */
787 	mad_adapter_info.payload.port_max_txu[0] = 0;
788 	/* If this fails, we get the defaults above */
789 	OF_getprop(OF_finddevice("/"), "ibm,partition-name",
790 	    mad_adapter_info.payload.partition_name,
791 	    sizeof(mad_adapter_info.payload.partition_name));
792 	OF_getprop(OF_finddevice("/"), "ibm,partition-no",
793 	    &mad_adapter_info.payload.partition_number,
794 	    sizeof(mad_adapter_info.payload.partition_number));
795 
796 	xp = TAILQ_FIRST(&sc->free_xferq);
797 	xp->ccb = NULL;
798 	TAILQ_REMOVE(&sc->free_xferq, xp, queue);
799 	TAILQ_INSERT_TAIL(&sc->active_xferq, xp, queue);
800 	xp->srp_iu_size = crq.iu_length = sizeof(mad_adapter_info);
801 	vmem_alloc(xp->sc->srp_iu_arena, xp->srp_iu_size,
802 	    M_BESTFIT | M_NOWAIT, &xp->srp_iu_offset);
803 	mad_adapter_info.buffer = xp->sc->srp_iu_phys + xp->srp_iu_offset + 24;
804 	mad_adapter_info.tag = (uint64_t)xp;
805 	memcpy((uint8_t *)xp->sc->srp_iu_queue + (uintptr_t)xp->srp_iu_offset,
806 		&mad_adapter_info, sizeof(mad_adapter_info));
807 	crq.valid = 0x80;
808 	crq.format = 0x02;
809 	crq.iu_data = xp->sc->srp_iu_phys + xp->srp_iu_offset;
810 	bus_dmamap_sync(sc->crq_tag, sc->crq_map, BUS_DMASYNC_PREWRITE);
811 	phyp_hcall(H_SEND_CRQ, xp->sc->unit, ((uint64_t *)(&crq))[0],
812 	    ((uint64_t *)(&crq))[1]);
813 
814 	while (TAILQ_EMPTY(&sc->free_xferq))
815 		vscsi_check_response_queue(sc);
816 
817 	/* Send SRP login */
818 	vscsi_srp_login(sc);
819 	while (sc->bus_logged_in == 0)
820 		vscsi_check_response_queue(sc);
821 
822 	error = phyp_hcall(H_VIO_SIGNAL, sc->unit, 1); /* Enable interrupts */
823 }
824 
825 
826 static void
827 vscsi_intr(void *xsc)
828 {
829 	struct vscsi_softc *sc = xsc;
830 
831 	mtx_lock(&sc->io_lock);
832 	vscsi_check_response_queue(sc);
833 	mtx_unlock(&sc->io_lock);
834 }
835 
836 static void
837 vscsi_srp_response(struct vscsi_xfer *xp, struct vscsi_crq *crq)
838 {
839 	union ccb *ccb = xp->ccb;
840 	struct vscsi_softc *sc = xp->sc;
841 	struct srp_rsp *rsp;
842 	uint32_t sense_len;
843 
844 	/* SRP response packet in original request */
845 	rsp = (struct srp_rsp *)((uint8_t *)sc->srp_iu_queue +
846 	    (uintptr_t)xp->srp_iu_offset);
847 	ccb->csio.scsi_status = rsp->status;
848 	if (ccb->csio.scsi_status == SCSI_STATUS_OK)
849 		ccb->ccb_h.status = CAM_REQ_CMP;
850 	else
851 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR;
852 #ifdef NOTYET
853 	/* Collect fast fail codes */
854 	if (crq->status != 0)
855 		ccb->ccb_h.status = CAM_REQ_CMP_ERR;
856 #endif
857 
858 	if (ccb->ccb_h.status != CAM_REQ_CMP) {
859 		ccb->ccb_h.status |= CAM_DEV_QFRZN;
860 		xpt_freeze_devq(ccb->ccb_h.path, /*count*/ 1);
861 	}
862 
863 	if (!(rsp->flags & SRP_RSPVALID))
864 		rsp->response_data_len = 0;
865 	if (!(rsp->flags & SRP_SNSVALID))
866 		rsp->sense_data_len = 0;
867 	if (!(rsp->flags & (SRP_DOOVER | SRP_DOUNDER)))
868 		rsp->data_out_resid = 0;
869 	if (!(rsp->flags & (SRP_DIOVER | SRP_DIUNDER)))
870 		rsp->data_in_resid = 0;
871 
872 	if (rsp->flags & SRP_SNSVALID) {
873 		bzero(&ccb->csio.sense_data, sizeof(struct scsi_sense_data));
874 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
875 		sense_len = min(be32toh(rsp->sense_data_len),
876 		    ccb->csio.sense_len);
877 		memcpy(&ccb->csio.sense_data,
878 		    &rsp->data_payload[be32toh(rsp->response_data_len)],
879 		    sense_len);
880 		ccb->csio.sense_resid = ccb->csio.sense_len -
881 		    be32toh(rsp->sense_data_len);
882 	}
883 
884 	switch (ccb->ccb_h.flags & CAM_DIR_MASK) {
885 	case CAM_DIR_OUT:
886 		ccb->csio.resid = rsp->data_out_resid;
887 		break;
888 	case CAM_DIR_IN:
889 		ccb->csio.resid = rsp->data_in_resid;
890 		break;
891 	}
892 
893 	bus_dmamap_sync(sc->data_tag, xp->dmamap, BUS_DMASYNC_POSTREAD);
894 	bus_dmamap_unload(sc->data_tag, xp->dmamap);
895 	xpt_done(ccb);
896 	xp->ccb = NULL;
897 }
898 
899 static void
900 vscsi_login_response(struct vscsi_xfer *xp, struct vscsi_crq *crq)
901 {
902 	struct vscsi_softc *sc = xp->sc;
903 	struct srp_login_rsp *rsp;
904 
905 	/* SRP response packet in original request */
906 	rsp = (struct srp_login_rsp *)((uint8_t *)sc->srp_iu_queue +
907 	    (uintptr_t)xp->srp_iu_offset);
908 	KASSERT(be16toh(rsp->buffer_formats) & 0x3, ("Both direct and indirect "
909 	    "buffers supported"));
910 
911 	sc->max_transactions = be32toh(rsp->request_limit_delta);
912 	device_printf(sc->dev, "Queue depth %d commands\n",
913 	    sc->max_transactions);
914 	sc->bus_logged_in = 1;
915 }
916 
917 static void
918 vscsi_cam_poll(struct cam_sim *sim)
919 {
920 	struct vscsi_softc *sc = cam_sim_softc(sim);
921 
922 	vscsi_check_response_queue(sc);
923 }
924 
925 static void
926 vscsi_check_response_queue(struct vscsi_softc *sc)
927 {
928 	struct vscsi_crq *crq;
929 	struct vscsi_xfer *xp;
930 	int code;
931 
932 	mtx_assert(&sc->io_lock, MA_OWNED);
933 
934 	phyp_hcall(H_VIO_SIGNAL, sc->unit, 0);
935 	bus_dmamap_sync(sc->crq_tag, sc->crq_map, BUS_DMASYNC_POSTREAD);
936 
937 	while (sc->crq_queue[sc->cur_crq].valid != 0) {
938 		crq = &sc->crq_queue[sc->cur_crq];
939 
940 		switch (crq->valid) {
941 		case 0xc0:
942 			if (crq->format == 0x02)
943 				sc->bus_initialized = 1;
944 			break;
945 		case 0x80:
946 			/* IU data is set to tag pointer (the XP) */
947 			xp = (struct vscsi_xfer *)crq->iu_data;
948 
949 			switch (crq->format) {
950 			case 0x01:
951 				code = *((uint8_t *)sc->srp_iu_queue +
952 	    			    (uintptr_t)xp->srp_iu_offset);
953 				switch (code) {
954 				case SRP_RSP:
955 					vscsi_srp_response(xp, crq);
956 					break;
957 				case SRP_LOGIN_RSP:
958 					vscsi_login_response(xp, crq);
959 					break;
960 				default:
961 					device_printf(sc->dev, "Unknown SRP "
962 					    "response code %d\n", code);
963 					break;
964 				}
965 				break;
966 			case 0x02:
967 				/* Ignore management datagrams */
968 				break;
969 			default:
970 				panic("Unknown CRQ format %d\n", crq->format);
971 				break;
972 			}
973 			vmem_free(sc->srp_iu_arena, xp->srp_iu_offset,
974 			    xp->srp_iu_size);
975 			TAILQ_REMOVE(&sc->active_xferq, xp, queue);
976 			TAILQ_INSERT_TAIL(&sc->free_xferq, xp, queue);
977 			break;
978 		default:
979 			device_printf(sc->dev,
980 			    "Unknown CRQ message type %d\n", crq->valid);
981 			break;
982 		}
983 
984 		crq->valid = 0;
985 		sc->cur_crq = (sc->cur_crq + 1) % sc->n_crqs;
986 	};
987 
988 	bus_dmamap_sync(sc->crq_tag, sc->crq_map, BUS_DMASYNC_PREWRITE);
989 	phyp_hcall(H_VIO_SIGNAL, sc->unit, 1);
990 }
991 
992