Home | History | Annotate | Line # | Download | only in dev
mesh.c revision 1.27.2.1
      1 /*	$NetBSD: mesh.c,v 1.27.2.1 2009/05/13 17:18:01 jym Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2000	Tsubai Masanari.
      5  * Copyright (c) 1999	Internet Research Institute, Inc.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by
     19  *	Internet Research Institute, Inc.
     20  * 4. The name of the author may not be used to endorse or promote products
     21  *    derived from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     32  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "$NetBSD: mesh.c,v 1.27.2.1 2009/05/13 17:18:01 jym Exp $");
     37 
     38 #include <sys/param.h>
     39 #include <sys/buf.h>
     40 #include <sys/device.h>
     41 #include <sys/errno.h>
     42 #include <sys/kernel.h>
     43 #include <sys/malloc.h>
     44 #include <sys/queue.h>
     45 #include <sys/systm.h>
     46 
     47 #include <uvm/uvm_extern.h>
     48 
     49 #include <dev/scsipi/scsi_all.h>
     50 #include <dev/scsipi/scsipi_all.h>
     51 #include <dev/scsipi/scsiconf.h>
     52 #include <dev/scsipi/scsi_message.h>
     53 
     54 #include <dev/ofw/openfirm.h>
     55 
     56 #include <machine/autoconf.h>
     57 #include <machine/cpu.h>
     58 #include <machine/pio.h>
     59 
     60 #include <macppc/dev/dbdma.h>
     61 #include <macppc/dev/meshreg.h>
     62 
     63 #ifdef MESH_DEBUG
     64 # define DPRINTF printf
     65 #else
     66 # define DPRINTF while (0) printf
     67 #endif
     68 
     69 #define T_SYNCMODE 0x01		/* target uses sync mode */
     70 #define T_SYNCNEGO 0x02		/* sync negotiation done */
     71 
     72 struct mesh_tinfo {
     73 	int flags;
     74 	int period;
     75 	int offset;
     76 };
     77 
     78 /* scb flags */
     79 #define MESH_POLL	0x01
     80 #define MESH_CHECK	0x02
     81 #define MESH_READ	0x80
     82 
     83 struct mesh_scb {
     84 	TAILQ_ENTRY(mesh_scb) chain;
     85 	int flags;
     86 	struct scsipi_xfer *xs;
     87 	struct scsipi_generic cmd;
     88 	int cmdlen;
     89 	int target;			/* target SCSI ID */
     90 	int resid;
     91 	vaddr_t daddr;
     92 	vsize_t dlen;
     93 	int status;
     94 };
     95 
     96 /* sc_flags value */
     97 #define MESH_DMA_ACTIVE	0x01
     98 
     99 struct mesh_softc {
    100 	struct device sc_dev;		/* us as a device */
    101 	struct scsipi_channel sc_channel;
    102 	struct scsipi_adapter sc_adapter;
    103 
    104 	u_char *sc_reg;			/* MESH base address */
    105 	dbdma_regmap_t *sc_dmareg;	/* DMA register address */
    106 	dbdma_command_t *sc_dmacmd;	/* DMA command area */
    107 
    108 	int sc_flags;
    109 	int sc_cfflags;			/* copy of config flags */
    110 	int sc_meshid;			/* MESH version */
    111 	int sc_minsync;			/* minimum sync period */
    112 	int sc_irq;
    113 	int sc_freq;			/* SCSI bus frequency in MHz */
    114 	int sc_id;			/* our SCSI ID */
    115 	struct mesh_tinfo sc_tinfo[8];	/* target information */
    116 
    117 	int sc_nextstate;
    118 	int sc_prevphase;
    119 	struct mesh_scb *sc_nexus;	/* current command */
    120 
    121 	int sc_msgout;
    122 	int sc_imsglen;
    123 	u_char sc_imsg[16];
    124 	u_char sc_omsg[16];
    125 
    126 	TAILQ_HEAD(, mesh_scb) free_scb;
    127 	TAILQ_HEAD(, mesh_scb) ready_scb;
    128 	struct mesh_scb sc_scb[16];
    129 };
    130 
    131 /* mesh_msgout() values */
    132 #define SEND_REJECT	1
    133 #define SEND_IDENTIFY	2
    134 #define SEND_SDTR	4
    135 
    136 static inline int mesh_read_reg(struct mesh_softc *, int);
    137 static inline void mesh_set_reg(struct mesh_softc *, int, int);
    138 
    139 int mesh_match(struct device *, struct cfdata *, void *);
    140 void mesh_attach(struct device *, struct device *, void *);
    141 void mesh_shutdownhook(void *);
    142 int mesh_intr(void *);
    143 void mesh_error(struct mesh_softc *, struct mesh_scb *, int, int);
    144 void mesh_select(struct mesh_softc *, struct mesh_scb *);
    145 void mesh_identify(struct mesh_softc *, struct mesh_scb *);
    146 void mesh_command(struct mesh_softc *, struct mesh_scb *);
    147 void mesh_dma_setup(struct mesh_softc *, struct mesh_scb *);
    148 void mesh_dataio(struct mesh_softc *, struct mesh_scb *);
    149 void mesh_status(struct mesh_softc *, struct mesh_scb *);
    150 void mesh_msgin(struct mesh_softc *, struct mesh_scb *);
    151 void mesh_msgout(struct mesh_softc *, int);
    152 void mesh_bus_reset(struct mesh_softc *);
    153 void mesh_reset(struct mesh_softc *);
    154 int mesh_stp(struct mesh_softc *, int);
    155 void mesh_setsync(struct mesh_softc *, struct mesh_tinfo *);
    156 struct mesh_scb *mesh_get_scb(struct mesh_softc *);
    157 void mesh_free_scb(struct mesh_softc *, struct mesh_scb *);
    158 void mesh_scsi_request(struct scsipi_channel *,
    159 				scsipi_adapter_req_t, void *);
    160 void mesh_sched(struct mesh_softc *);
    161 int mesh_poll(struct mesh_softc *, struct scsipi_xfer *);
    162 void mesh_done(struct mesh_softc *, struct mesh_scb *);
    163 void mesh_timeout(void *);
    164 void mesh_minphys(struct buf *);
    165 
    166 
    167 #define MESH_DATAOUT	0
    168 #define MESH_DATAIN	MESH_STATUS0_IO
    169 #define MESH_COMMAND	MESH_STATUS0_CD
    170 #define MESH_STATUS	(MESH_STATUS0_CD | MESH_STATUS0_IO)
    171 #define MESH_MSGOUT	(MESH_STATUS0_MSG | MESH_STATUS0_CD)
    172 #define MESH_MSGIN	(MESH_STATUS0_MSG | MESH_STATUS0_CD | MESH_STATUS0_IO)
    173 
    174 #define MESH_SELECTING	8
    175 #define MESH_IDENTIFY	9
    176 #define MESH_COMPLETE	10
    177 #define MESH_BUSFREE	11
    178 #define MESH_UNKNOWN	-1
    179 
    180 #define MESH_PHASE_MASK	(MESH_STATUS0_MSG | MESH_STATUS0_CD | MESH_STATUS0_IO)
    181 
    182 CFATTACH_DECL(mesh, sizeof(struct mesh_softc),
    183     mesh_match, mesh_attach, NULL, NULL);
    184 
    185 int
    186 mesh_match(struct device *parent, struct cfdata *cf, void *aux)
    187 {
    188 	struct confargs *ca = aux;
    189 	char compat[32];
    190 
    191 	if (strcmp(ca->ca_name, "mesh") == 0)
    192 		return 1;
    193 
    194 	memset(compat, 0, sizeof(compat));
    195 	OF_getprop(ca->ca_node, "compatible", compat, sizeof(compat));
    196 	if (strcmp(compat, "chrp,mesh0") == 0)
    197 		return 1;
    198 
    199 	return 0;
    200 }
    201 
    202 void
    203 mesh_attach(struct device *parent, struct device *self, void *aux)
    204 {
    205 	struct mesh_softc *sc = (void *)self;
    206 	struct confargs *ca = aux;
    207 	int i;
    208 	u_int *reg;
    209 
    210 	reg = ca->ca_reg;
    211 	reg[0] += ca->ca_baseaddr;
    212 	reg[2] += ca->ca_baseaddr;
    213 	sc->sc_reg = mapiodev(reg[0], reg[1]);
    214 	sc->sc_irq = ca->ca_intr[0];
    215 	sc->sc_dmareg = mapiodev(reg[2], reg[3]);
    216 
    217 	sc->sc_cfflags = device_cfdata(self)->cf_flags;
    218 	sc->sc_meshid = mesh_read_reg(sc, MESH_MESH_ID) & 0x1f;
    219 #if 0
    220 	if (sc->sc_meshid != (MESH_SIGNATURE & 0x1f) {
    221 		printf(": unknown MESH ID (0x%x)\n", sc->sc_meshid);
    222 		return;
    223 	}
    224 #endif
    225 	if (OF_getprop(ca->ca_node, "clock-frequency", &sc->sc_freq, 4) != 4) {
    226 		printf(": cannot get clock-frequency\n");
    227 		return;
    228 	}
    229 	sc->sc_freq /= 1000000;	/* in MHz */
    230 	sc->sc_minsync = 25;	/* maximum sync rate = 10MB/sec */
    231 	sc->sc_id = 7;
    232 
    233 	TAILQ_INIT(&sc->free_scb);
    234 	TAILQ_INIT(&sc->ready_scb);
    235 	for (i = 0; i < sizeof(sc->sc_scb)/sizeof(sc->sc_scb[0]); i++)
    236 		TAILQ_INSERT_TAIL(&sc->free_scb, &sc->sc_scb[i], chain);
    237 
    238 	sc->sc_dmacmd = dbdma_alloc(sizeof(dbdma_command_t) * 20);
    239 
    240 	mesh_reset(sc);
    241 	mesh_bus_reset(sc);
    242 
    243 	printf(" irq %d: %dMHz, SCSI ID %d\n",
    244 		sc->sc_irq, sc->sc_freq, sc->sc_id);
    245 
    246 	sc->sc_adapter.adapt_dev = &sc->sc_dev;
    247 	sc->sc_adapter.adapt_nchannels = 1;
    248 	sc->sc_adapter.adapt_openings = 7;
    249 	sc->sc_adapter.adapt_max_periph = 1;
    250 	sc->sc_adapter.adapt_ioctl = NULL;
    251 	sc->sc_adapter.adapt_minphys = mesh_minphys;
    252 	sc->sc_adapter.adapt_request = mesh_scsi_request;
    253 
    254 	sc->sc_channel.chan_adapter = &sc->sc_adapter;
    255 	sc->sc_channel.chan_bustype = &scsi_bustype;
    256 	sc->sc_channel.chan_channel = 0;
    257 	sc->sc_channel.chan_ntargets = 8;
    258 	sc->sc_channel.chan_nluns = 8;
    259 	sc->sc_channel.chan_id = sc->sc_id;
    260 
    261 	config_found(&sc->sc_dev, &sc->sc_channel, scsiprint);
    262 
    263 	intr_establish(sc->sc_irq, IST_EDGE, IPL_BIO, mesh_intr, sc);
    264 
    265 	/* Reset SCSI bus when halt. */
    266 	shutdownhook_establish(mesh_shutdownhook, sc);
    267 }
    268 
    269 #define MESH_SET_XFER(sc, count) do {					\
    270 	mesh_set_reg(sc, MESH_XFER_COUNT0, count);			\
    271 	mesh_set_reg(sc, MESH_XFER_COUNT1, count >> 8);			\
    272 } while (0)
    273 
    274 #define MESH_GET_XFER(sc) ((mesh_read_reg(sc, MESH_XFER_COUNT1) << 8) |	\
    275 			   mesh_read_reg(sc, MESH_XFER_COUNT0))
    276 
    277 int
    278 mesh_read_reg(struct mesh_softc *sc, int reg)
    279 {
    280 	return in8(sc->sc_reg + reg);
    281 }
    282 
    283 void
    284 mesh_set_reg(struct mesh_softc *sc, int reg, int val)
    285 {
    286 	out8(sc->sc_reg + reg, val);
    287 }
    288 
    289 void
    290 mesh_shutdownhook(void *arg)
    291 {
    292 	struct mesh_softc *sc = arg;
    293 
    294 	/* Set to async mode. */
    295 	mesh_set_reg(sc, MESH_SYNC_PARAM, 2);
    296 	mesh_bus_reset(sc);
    297 }
    298 
    299 #ifdef MESH_DEBUG
    300 static char scsi_phase[][8] = {
    301 	"DATAOUT",
    302 	"DATAIN",
    303 	"COMMAND",
    304 	"STATUS",
    305 	"",
    306 	"",
    307 	"MSGOUT",
    308 	"MSGIN"
    309 };
    310 #endif
    311 
    312 int
    313 mesh_intr(void *arg)
    314 {
    315 	struct mesh_softc *sc = arg;
    316 	struct mesh_scb *scb;
    317 	int fifocnt;
    318 	u_char intr, exception, error, status0, status1;
    319 
    320 	intr = mesh_read_reg(sc, MESH_INTERRUPT);
    321 	if (intr == 0) {
    322 		DPRINTF("%s: stray interrupt\n", sc->sc_dev.dv_xname);
    323 		return 0;
    324 	}
    325 
    326 	exception = mesh_read_reg(sc, MESH_EXCEPTION);
    327 	error = mesh_read_reg(sc, MESH_ERROR);
    328 	status0 = mesh_read_reg(sc, MESH_BUS_STATUS0);
    329 	status1 = mesh_read_reg(sc, MESH_BUS_STATUS1);
    330 
    331 	/* clear interrupt */
    332 	mesh_set_reg(sc, MESH_INTERRUPT, intr);
    333 
    334 #ifdef MESH_DEBUG
    335 {
    336 	char buf1[64], buf2[64];
    337 
    338 	snprintb(buf1, sizeof buf1, MESH_STATUS0_BITMASK, status0);
    339 	snprintb(buf2, sizeof buf2, MESH_EXC_BITMASK, exception);
    340 	printf("mesh_intr status0 = 0x%s (%s), exc = 0x%s\n",
    341 	    buf1, scsi_phase[status0 & 7], buf2);
    342 }
    343 #endif
    344 
    345 	scb = sc->sc_nexus;
    346 	if (scb == NULL) {
    347 		DPRINTF("%s: NULL nexus\n", sc->sc_dev.dv_xname);
    348 		return 1;
    349 	}
    350 
    351 	if (intr & MESH_INTR_CMDDONE) {
    352 		if (sc->sc_flags & MESH_DMA_ACTIVE) {
    353 			dbdma_stop(sc->sc_dmareg);
    354 
    355 			sc->sc_flags &= ~MESH_DMA_ACTIVE;
    356 			scb->resid = MESH_GET_XFER(sc);
    357 
    358 			fifocnt = mesh_read_reg(sc, MESH_FIFO_COUNT);
    359 			if (fifocnt != 0) {
    360 				if (scb->flags & MESH_READ) {
    361 					char *cp;
    362 
    363 					cp = (char *)scb->daddr + scb->dlen
    364 						- fifocnt;
    365 					DPRINTF("fifocnt = %d, resid = %d\n",
    366 						fifocnt, scb->resid);
    367 					while (fifocnt > 0) {
    368 						*cp++ = mesh_read_reg(sc,
    369 								MESH_FIFO);
    370 						fifocnt--;
    371 					}
    372 				} else {
    373 					mesh_set_reg(sc, MESH_SEQUENCE,
    374 							MESH_CMD_FLUSH_FIFO);
    375 				}
    376 			} else {
    377 				/* Clear all interrupts */
    378 				mesh_set_reg(sc, MESH_INTERRUPT, 7);
    379 			}
    380 		}
    381 	}
    382 
    383 	if (intr & MESH_INTR_ERROR) {
    384 		printf("%s: error %02x %02x\n",
    385 			sc->sc_dev.dv_xname, error, exception);
    386 		mesh_error(sc, scb, error, 0);
    387 		return 1;
    388 	}
    389 
    390 	if (intr & MESH_INTR_EXCEPTION) {
    391 		/* selection timeout */
    392 		if (exception & MESH_EXC_SELTO) {
    393 			mesh_error(sc, scb, 0, exception);
    394 			return 1;
    395 		}
    396 
    397 		/* phase mismatch */
    398 		if (exception & MESH_EXC_PHASEMM) {
    399 			DPRINTF("%s: PHASE MISMATCH; nextstate = %d -> ",
    400 				sc->sc_dev.dv_xname, sc->sc_nextstate);
    401 			sc->sc_nextstate = status0 & MESH_PHASE_MASK;
    402 
    403 			DPRINTF("%d, resid = %d\n",
    404 				sc->sc_nextstate, scb->resid);
    405 		}
    406 	}
    407 
    408 	if (sc->sc_nextstate == MESH_UNKNOWN)
    409 		sc->sc_nextstate = status0 & MESH_PHASE_MASK;
    410 
    411 	switch (sc->sc_nextstate) {
    412 
    413 	case MESH_IDENTIFY:
    414 		mesh_identify(sc, scb);
    415 		break;
    416 	case MESH_COMMAND:
    417 		mesh_command(sc, scb);
    418 		break;
    419 	case MESH_DATAIN:
    420 	case MESH_DATAOUT:
    421 		mesh_dataio(sc, scb);
    422 		break;
    423 	case MESH_STATUS:
    424 		mesh_status(sc, scb);
    425 		break;
    426 	case MESH_MSGIN:
    427 		mesh_msgin(sc, scb);
    428 		break;
    429 	case MESH_COMPLETE:
    430 		mesh_done(sc, scb);
    431 		break;
    432 
    433 	default:
    434 		printf("%s: unknown state (%d)\n", sc->sc_dev.dv_xname,
    435 		    sc->sc_nextstate);
    436 		scb->xs->error = XS_DRIVER_STUFFUP;
    437 		mesh_done(sc, scb);
    438 	}
    439 
    440 	return 1;
    441 }
    442 
    443 void
    444 mesh_error(struct mesh_softc *sc, struct mesh_scb *scb, int error, int exception)
    445 {
    446 	if (error & MESH_ERR_SCSI_RESET) {
    447 		printf("%s: SCSI RESET\n", sc->sc_dev.dv_xname);
    448 
    449 		/* Wait until the RST signal is deasserted. */
    450 		while (mesh_read_reg(sc, MESH_BUS_STATUS1) & MESH_STATUS1_RST);
    451 		mesh_reset(sc);
    452 		return;
    453 	}
    454 
    455 	if (error & MESH_ERR_PARITY_ERR0) {
    456 		printf("%s: parity error\n", sc->sc_dev.dv_xname);
    457 		scb->xs->error = XS_DRIVER_STUFFUP;
    458 	}
    459 
    460 	if (error & MESH_ERR_DISCONNECT) {
    461 		printf("%s: unexpected disconnect\n", sc->sc_dev.dv_xname);
    462 		if (sc->sc_nextstate != MESH_COMPLETE)
    463 			scb->xs->error = XS_DRIVER_STUFFUP;
    464 	}
    465 
    466 	if (exception & MESH_EXC_SELTO) {
    467 		/* XXX should reset bus here? */
    468 		scb->xs->error = XS_SELTIMEOUT;
    469 	}
    470 
    471 	mesh_done(sc, scb);
    472 }
    473 
    474 void
    475 mesh_select(struct mesh_softc *sc, struct mesh_scb *scb)
    476 {
    477 	struct mesh_tinfo *ti = &sc->sc_tinfo[scb->target];
    478 	int timeout;
    479 
    480 	DPRINTF("mesh_select\n");
    481 
    482 	mesh_setsync(sc, ti);
    483 	MESH_SET_XFER(sc, 0);
    484 
    485 	/* arbitration */
    486 
    487 	/*
    488 	 * MESH mistakenly asserts TARGET ID bit along with its own ID bit
    489 	 * in arbitration phase (like selection).  So we should load
    490 	 * initiator ID to DestID register temporarily.
    491 	 */
    492 	mesh_set_reg(sc, MESH_DEST_ID, sc->sc_id);
    493 	mesh_set_reg(sc, MESH_INTR_MASK, 0);	/* disable intr. */
    494 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_ARBITRATE);
    495 
    496 	while (mesh_read_reg(sc, MESH_INTERRUPT) == 0);
    497 	mesh_set_reg(sc, MESH_INTERRUPT, 1);
    498 	mesh_set_reg(sc, MESH_INTR_MASK, 7);
    499 
    500 	/* selection */
    501 	mesh_set_reg(sc, MESH_DEST_ID, scb->target);
    502 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_SELECT | MESH_SEQ_ATN);
    503 
    504 	sc->sc_prevphase = MESH_SELECTING;
    505 	sc->sc_nextstate = MESH_IDENTIFY;
    506 
    507 	timeout = mstohz(scb->xs->timeout);
    508 	if (timeout == 0)
    509 		timeout = 1;
    510 
    511 	callout_reset(&scb->xs->xs_callout, timeout, mesh_timeout, scb);
    512 }
    513 
    514 void
    515 mesh_identify(struct mesh_softc *sc, struct mesh_scb *scb)
    516 {
    517 	struct mesh_tinfo *ti = &sc->sc_tinfo[scb->target];
    518 
    519 	DPRINTF("mesh_identify\n");
    520 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_FLUSH_FIFO);
    521 
    522 	if ((ti->flags & T_SYNCNEGO) == 0) {
    523 		ti->period = sc->sc_minsync;
    524 		ti->offset = 15;
    525 		mesh_msgout(sc, SEND_IDENTIFY | SEND_SDTR);
    526 		sc->sc_nextstate = MESH_MSGIN;
    527 	} else {
    528 		mesh_msgout(sc, SEND_IDENTIFY);
    529 		sc->sc_nextstate = MESH_COMMAND;
    530 	}
    531 }
    532 
    533 void
    534 mesh_command(struct mesh_softc *sc, struct mesh_scb *scb)
    535 {
    536 	int i;
    537 	char *cmdp;
    538 
    539 #ifdef MESH_DEBUG
    540 	printf("mesh_command cdb = %02x", scb->cmd.opcode);
    541 	for (i = 0; i < 5; i++)
    542 		printf(" %02x", scb->cmd.bytes[i]);
    543 	printf("\n");
    544 #endif
    545 
    546 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_FLUSH_FIFO);
    547 
    548 	MESH_SET_XFER(sc, scb->cmdlen);
    549 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_COMMAND);
    550 
    551 	cmdp = (char *)&scb->cmd;
    552 	for (i = 0; i < scb->cmdlen; i++)
    553 		mesh_set_reg(sc, MESH_FIFO, *cmdp++);
    554 
    555 	if (scb->resid == 0)
    556 		sc->sc_nextstate = MESH_STATUS;		/* no data xfer */
    557 	else
    558 		sc->sc_nextstate = MESH_DATAIN;
    559 }
    560 
    561 void
    562 mesh_dma_setup(struct mesh_softc *sc, struct mesh_scb *scb)
    563 {
    564 	int datain = scb->flags & MESH_READ;
    565 	dbdma_command_t *cmdp;
    566 	u_int cmd;
    567 	vaddr_t va;
    568 	int count, offset;
    569 
    570 	cmdp = sc->sc_dmacmd;
    571 	cmd = datain ? DBDMA_CMD_IN_MORE : DBDMA_CMD_OUT_MORE;
    572 
    573 	count = scb->dlen;
    574 
    575 	if (count / PAGE_SIZE > 32)
    576 		panic("mesh: transfer size >= 128k");
    577 
    578 	va = scb->daddr;
    579 	offset = va & PGOFSET;
    580 
    581 	/* if va is not page-aligned, setup the first page */
    582 	if (offset != 0) {
    583 		int rest = PAGE_SIZE - offset;	/* the rest in the page */
    584 
    585 		if (count > rest) {		/* if continues to next page */
    586 			DBDMA_BUILD(cmdp, cmd, 0, rest, vtophys(va),
    587 				DBDMA_INT_NEVER, DBDMA_WAIT_NEVER,
    588 				DBDMA_BRANCH_NEVER);
    589 			count -= rest;
    590 			va += rest;
    591 			cmdp++;
    592 		}
    593 	}
    594 
    595 	/* now va is page-aligned */
    596 	while (count > PAGE_SIZE) {
    597 		DBDMA_BUILD(cmdp, cmd, 0, PAGE_SIZE, vtophys(va),
    598 			DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    599 		count -= PAGE_SIZE;
    600 		va += PAGE_SIZE;
    601 		cmdp++;
    602 	}
    603 
    604 	/* the last page (count <= PAGE_SIZE here) */
    605 	cmd = datain ? DBDMA_CMD_IN_LAST : DBDMA_CMD_OUT_LAST;
    606 	DBDMA_BUILD(cmdp, cmd , 0, count, vtophys(va),
    607 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    608 	cmdp++;
    609 
    610 	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
    611 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    612 }
    613 
    614 void
    615 mesh_dataio(struct mesh_softc *sc, struct mesh_scb *scb)
    616 {
    617 	DPRINTF("mesh_dataio len = %ld (%s)\n", scb->dlen,
    618 		scb->flags & MESH_READ ? "read" : "write");
    619 
    620 	mesh_dma_setup(sc, scb);
    621 
    622 	if (scb->dlen == 65536)
    623 		MESH_SET_XFER(sc, 0);	/* TC = 0 means 64KB transfer */
    624 	else
    625 		MESH_SET_XFER(sc, scb->dlen);
    626 
    627 	if (scb->flags & MESH_READ)
    628 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_DATAIN | MESH_SEQ_DMA);
    629 	else
    630 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_DATAOUT | MESH_SEQ_DMA);
    631 	dbdma_start(sc->sc_dmareg, sc->sc_dmacmd);
    632 	sc->sc_flags |= MESH_DMA_ACTIVE;
    633 	sc->sc_nextstate = MESH_STATUS;
    634 }
    635 
    636 void
    637 mesh_status(struct mesh_softc *sc, struct mesh_scb *scb)
    638 {
    639 	if (mesh_read_reg(sc, MESH_FIFO_COUNT) == 0) {	/* XXX cheat */
    640 		DPRINTF("mesh_status(0)\n");
    641 		MESH_SET_XFER(sc, 1);
    642 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_STATUS);
    643 		sc->sc_nextstate = MESH_STATUS;
    644 		return;
    645 	}
    646 
    647 	scb->status = mesh_read_reg(sc, MESH_FIFO);
    648 	DPRINTF("mesh_status(1): status = 0x%x\n", scb->status);
    649 	if (mesh_read_reg(sc, MESH_FIFO_COUNT) != 0)
    650 		DPRINTF("FIFO_COUNT=%d\n", mesh_read_reg(sc, MESH_FIFO_COUNT));
    651 
    652 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_FLUSH_FIFO);
    653 	MESH_SET_XFER(sc, 1);
    654 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_MSGIN);
    655 
    656 	sc->sc_nextstate = MESH_MSGIN;
    657 }
    658 
    659 void
    660 mesh_msgin(struct mesh_softc *sc, struct mesh_scb *scb)
    661 {
    662 	DPRINTF("mesh_msgin\n");
    663 
    664 	if (mesh_read_reg(sc, MESH_FIFO_COUNT) == 0) {	/* XXX cheat */
    665 		MESH_SET_XFER(sc, 1);
    666 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_MSGIN);
    667 		sc->sc_imsglen = 0;
    668 		sc->sc_nextstate = MESH_MSGIN;
    669 		return;
    670 	}
    671 
    672 	sc->sc_imsg[sc->sc_imsglen++] = mesh_read_reg(sc, MESH_FIFO);
    673 
    674 	if (sc->sc_imsglen == 1 && MSG_IS1BYTE(sc->sc_imsg[0]))
    675 		goto gotit;
    676 	if (sc->sc_imsglen == 2 && MSG_IS2BYTE(sc->sc_imsg[0]))
    677 		goto gotit;
    678 	if (sc->sc_imsglen >= 3 && MSG_ISEXTENDED(sc->sc_imsg[0]) &&
    679 	    sc->sc_imsglen == sc->sc_imsg[1] + 2)
    680 		goto gotit;
    681 
    682 	sc->sc_nextstate = MESH_MSGIN;
    683 	MESH_SET_XFER(sc, 1);
    684 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_MSGIN);
    685 	return;
    686 
    687 gotit:
    688 #ifdef MESH_DEBUG
    689 	printf("msgin:");
    690 	for (i = 0; i < sc->sc_imsglen; i++)
    691 		printf(" 0x%02x", sc->sc_imsg[i]);
    692 	printf("\n");
    693 #endif
    694 
    695 	switch (sc->sc_imsg[0]) {
    696 	case MSG_CMDCOMPLETE:
    697 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_BUSFREE);
    698 		sc->sc_nextstate = MESH_COMPLETE;
    699 		sc->sc_imsglen = 0;
    700 		return;
    701 
    702 	case MSG_MESSAGE_REJECT:
    703 		if (sc->sc_msgout & SEND_SDTR) {
    704 			printf("SDTR rejected\n");
    705 			printf("using async mode\n");
    706 			sc->sc_tinfo[scb->target].period = 0;
    707 			sc->sc_tinfo[scb->target].offset = 0;
    708 			mesh_setsync(sc, &sc->sc_tinfo[scb->target]);
    709 			break;
    710 		}
    711 		break;
    712 
    713 	case MSG_NOOP:
    714 		break;
    715 
    716 	case MSG_EXTENDED:
    717 		goto extended_msg;
    718 
    719 	default:
    720 		scsipi_printaddr(scb->xs->xs_periph);
    721 		printf("unrecognized MESSAGE(0x%02x); sending REJECT\n",
    722 			sc->sc_imsg[0]);
    723 
    724 	reject:
    725 		mesh_msgout(sc, SEND_REJECT);
    726 		return;
    727 	}
    728 	goto done;
    729 
    730 extended_msg:
    731 	/* process an extended message */
    732 	switch (sc->sc_imsg[2]) {
    733 	case MSG_EXT_SDTR:
    734 	  {
    735 		struct mesh_tinfo *ti = &sc->sc_tinfo[scb->target];
    736 		int period = sc->sc_imsg[3];
    737 		int offset = sc->sc_imsg[4];
    738 		int r = 250 / period;
    739 		int s = (100*250) / period - 100 * r;
    740 
    741 		if (period < sc->sc_minsync) {
    742 			ti->period = sc->sc_minsync;
    743 			ti->offset = 15;
    744 			mesh_msgout(sc, SEND_SDTR);
    745 			return;
    746 		}
    747 		scsipi_printaddr(scb->xs->xs_periph);
    748 		/* XXX if (offset != 0) ... */
    749 		printf("max sync rate %d.%02dMb/s\n", r, s);
    750 		ti->period = period;
    751 		ti->offset = offset;
    752 		ti->flags |= T_SYNCNEGO;
    753 		ti->flags |= T_SYNCMODE;
    754 		mesh_setsync(sc, ti);
    755 		goto done;
    756 	  }
    757 	default:
    758 		printf("%s target %d: rejecting extended message 0x%x\n",
    759 			sc->sc_dev.dv_xname, scb->target, sc->sc_imsg[0]);
    760 		goto reject;
    761 	}
    762 
    763 done:
    764 	sc->sc_imsglen = 0;
    765 	sc->sc_nextstate = MESH_UNKNOWN;
    766 
    767 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_BUSFREE); /* XXX really? */
    768 }
    769 
    770 void
    771 mesh_msgout(struct mesh_softc *sc, int msg)
    772 {
    773 	struct mesh_scb *scb = sc->sc_nexus;
    774 	struct mesh_tinfo *ti;
    775 	int lun, len, i;
    776 
    777 	DPRINTF("mesh_msgout: sending");
    778 
    779 	sc->sc_msgout = msg;
    780 	len = 0;
    781 
    782 	if (msg & SEND_REJECT) {
    783 		DPRINTF(" REJECT");
    784 		sc->sc_omsg[len++] = MSG_MESSAGE_REJECT;
    785 	}
    786 	if (msg & SEND_IDENTIFY) {
    787 		DPRINTF(" IDENTIFY");
    788 		lun = scb->xs->xs_periph->periph_lun;
    789 		sc->sc_omsg[len++] = MSG_IDENTIFY(lun, 0);
    790 	}
    791 	if (msg & SEND_SDTR) {
    792 		DPRINTF(" SDTR");
    793 		ti = &sc->sc_tinfo[scb->target];
    794 		sc->sc_omsg[len++] = MSG_EXTENDED;
    795 		sc->sc_omsg[len++] = 3;
    796 		sc->sc_omsg[len++] = MSG_EXT_SDTR;
    797 		sc->sc_omsg[len++] = ti->period;
    798 		sc->sc_omsg[len++] = ti->offset;
    799 	}
    800 	DPRINTF("\n");
    801 
    802 	MESH_SET_XFER(sc, len);
    803 	if (len == 1) {
    804 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_MSGOUT);
    805 		mesh_set_reg(sc, MESH_FIFO, sc->sc_omsg[0]);
    806 	} else {
    807 		mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_MSGOUT | MESH_SEQ_ATN);
    808 
    809 		for (i = 0; i < len - 1; i++)
    810 			mesh_set_reg(sc, MESH_FIFO, sc->sc_omsg[i]);
    811 
    812 		/* Wait for the FIFO empty... */
    813 		while (mesh_read_reg(sc, MESH_FIFO_COUNT) > 0);
    814 
    815 		/* ...then write the last byte. */
    816 		mesh_set_reg(sc, MESH_FIFO, sc->sc_omsg[i]);
    817 	}
    818 	sc->sc_nextstate = MESH_UNKNOWN;
    819 }
    820 
    821 void
    822 mesh_bus_reset(struct mesh_softc *sc)
    823 {
    824 	DPRINTF("mesh_bus_reset\n");
    825 
    826 	/* Disable interrupts. */
    827 	mesh_set_reg(sc, MESH_INTR_MASK, 0);
    828 
    829 	/* Assert RST line. */
    830 	mesh_set_reg(sc, MESH_BUS_STATUS1, MESH_STATUS1_RST);
    831 	delay(50);
    832 	mesh_set_reg(sc, MESH_BUS_STATUS1, 0);
    833 
    834 	mesh_reset(sc);
    835 }
    836 
    837 void
    838 mesh_reset(struct mesh_softc *sc)
    839 {
    840 	int i;
    841 
    842 	DPRINTF("mesh_reset\n");
    843 
    844 	/* Reset DMA first. */
    845 	dbdma_reset(sc->sc_dmareg);
    846 
    847 	/* Disable interrupts. */
    848 	mesh_set_reg(sc, MESH_INTR_MASK, 0);
    849 
    850 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_RESET_MESH);
    851 	delay(1);
    852 
    853 	/* Wait for reset done. */
    854 	while (mesh_read_reg(sc, MESH_INTERRUPT) == 0);
    855 
    856 	/* Clear interrupts */
    857 	mesh_set_reg(sc, MESH_INTERRUPT, 0x7);
    858 
    859 	/* Set SCSI ID */
    860 	mesh_set_reg(sc, MESH_SOURCE_ID, sc->sc_id);
    861 
    862 	/* Set to async mode by default. */
    863 	mesh_set_reg(sc, MESH_SYNC_PARAM, 2);
    864 
    865 	/* Set selection timeout to 250ms. */
    866 	mesh_set_reg(sc, MESH_SEL_TIMEOUT, 250 * sc->sc_freq / 500);
    867 
    868 	/* Enable parity check. */
    869 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_ENABLE_PARITY);
    870 
    871 	/* Enable all interrupts. */
    872 	mesh_set_reg(sc, MESH_INTR_MASK, 0x7);
    873 
    874 	for (i = 0; i < 7; i++) {
    875 		struct mesh_tinfo *ti = &sc->sc_tinfo[i];
    876 
    877 		ti->flags = 0;
    878 		ti->period = ti->offset = 0;
    879 		if (sc->sc_cfflags & (0x100 << i))
    880 			ti->flags |= T_SYNCNEGO;
    881 	}
    882 	sc->sc_nexus = NULL;
    883 }
    884 
    885 int
    886 mesh_stp(struct mesh_softc *sc, int v)
    887 {
    888 	/*
    889 	 * stp(v) = 5 * clock_period         (v == 0)
    890 	 *        = (v + 2) * 2 clock_period (v > 0)
    891 	 */
    892 
    893 	if (v == 0)
    894 		return 5 * 250 / sc->sc_freq;
    895 	else
    896 		return (v + 2) * 2 * 250 / sc->sc_freq;
    897 }
    898 
    899 void
    900 mesh_setsync(struct mesh_softc *sc, struct mesh_tinfo *ti)
    901 {
    902 	int period = ti->period;
    903 	int offset = ti->offset;
    904 	int v;
    905 
    906 	if ((ti->flags & T_SYNCMODE) == 0)
    907 		offset = 0;
    908 
    909 	if (offset == 0) {	/* async mode */
    910 		mesh_set_reg(sc, MESH_SYNC_PARAM, 2);
    911 		return;
    912 	}
    913 
    914 	v = period * sc->sc_freq / 250 / 2 - 2;
    915 	if (v < 0)
    916 		v = 0;
    917 	if (mesh_stp(sc, v) < period)
    918 		v++;
    919 	if (v > 15)
    920 		v = 15;
    921 	mesh_set_reg(sc, MESH_SYNC_PARAM, (offset << 4) | v);
    922 }
    923 
    924 struct mesh_scb *
    925 mesh_get_scb(struct mesh_softc *sc)
    926 {
    927 	struct mesh_scb *scb;
    928 	int s;
    929 
    930 	s = splbio();
    931 	if ((scb = sc->free_scb.tqh_first) != NULL)
    932 		TAILQ_REMOVE(&sc->free_scb, scb, chain);
    933 	splx(s);
    934 
    935 	return scb;
    936 }
    937 
    938 void
    939 mesh_free_scb(struct mesh_softc *sc, struct mesh_scb *scb)
    940 {
    941 	int s;
    942 
    943 	s = splbio();
    944 	TAILQ_INSERT_HEAD(&sc->free_scb, scb, chain);
    945 	splx(s);
    946 }
    947 
    948 void
    949 mesh_scsi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req, void *arg)
    950 {
    951 	struct scsipi_xfer *xs;
    952 	struct scsipi_periph *periph;
    953 	struct mesh_softc *sc = (void *)chan->chan_adapter->adapt_dev;
    954 	struct mesh_scb *scb;
    955 	u_int flags;
    956 	int s;
    957 
    958 	switch (req) {
    959 	case ADAPTER_REQ_RUN_XFER:
    960 		xs = arg;
    961 		periph = xs->xs_periph;
    962 		flags = xs->xs_control;
    963 
    964 
    965 		if ((scb = mesh_get_scb(sc)) == NULL) {
    966 			xs->error = XS_RESOURCE_SHORTAGE;
    967 			scsipi_done(xs);
    968 			return;
    969 		}
    970 		scb->xs = xs;
    971 		scb->flags = 0;
    972 		scb->status = 0;
    973 		scb->daddr = (vaddr_t)xs->data;
    974 		scb->dlen = xs->datalen;
    975 		scb->resid = xs->datalen;
    976 		memcpy(&scb->cmd, xs->cmd, xs->cmdlen);
    977 		scb->cmdlen = xs->cmdlen;
    978 		scb->target = periph->periph_target;
    979 		sc->sc_imsglen = 0;	/* XXX ? */
    980 
    981 #ifdef MESH_DEBUG
    982 {
    983 		int i;
    984 		printf("mesh_scsi_cmd: target = %d, cdb = %02x",
    985 		       scb->target, scb->cmd.opcode);
    986 		for (i = 0; i < 5; i++)
    987 			printf(" %02x", scb->cmd.bytes[i]);
    988 		printf("\n");
    989 }
    990 #endif
    991 
    992 		if (flags & XS_CTL_POLL)
    993 			scb->flags |= MESH_POLL;
    994 #if 0
    995 		if (flags & XS_CTL_DATA_OUT)
    996 			scb->flags &= ~MESH_READ;
    997 #endif
    998 		if (flags & XS_CTL_DATA_IN)
    999 			scb->flags |= MESH_READ;
   1000 
   1001 		s = splbio();
   1002 
   1003 		TAILQ_INSERT_TAIL(&sc->ready_scb, scb, chain);
   1004 
   1005 		if (sc->sc_nexus == NULL)	/* IDLE */
   1006 			mesh_sched(sc);
   1007 
   1008 		splx(s);
   1009 
   1010 		if ((flags & XS_CTL_POLL) == 0)
   1011 			return;
   1012 
   1013 		if (mesh_poll(sc, xs)) {
   1014 			printf("%s: timeout\n", sc->sc_dev.dv_xname);
   1015 			if (mesh_poll(sc, xs))
   1016 				printf("%s: timeout again\n", sc->sc_dev.dv_xname);
   1017 		}
   1018 		return;
   1019 
   1020 	case ADAPTER_REQ_GROW_RESOURCES:
   1021 		/* XXX Not supported. */
   1022 		return;
   1023 
   1024 	case ADAPTER_REQ_SET_XFER_MODE:
   1025 		/* XXX Not supported. */
   1026 		return;
   1027 	}
   1028 
   1029 }
   1030 
   1031 void
   1032 mesh_sched(struct mesh_softc *sc)
   1033 {
   1034 	struct scsipi_xfer *xs;
   1035 	struct mesh_scb *scb;
   1036 
   1037 	scb = sc->ready_scb.tqh_first;
   1038 start:
   1039 	if (scb == NULL)
   1040 		return;
   1041 
   1042 	xs = scb->xs;
   1043 
   1044 	if (sc->sc_nexus == NULL) {
   1045 		TAILQ_REMOVE(&sc->ready_scb, scb, chain);
   1046 		sc->sc_nexus = scb;
   1047 		mesh_select(sc, scb);
   1048 		return;
   1049 	}
   1050 
   1051 	scb = scb->chain.tqe_next;
   1052 	goto start;
   1053 }
   1054 
   1055 int
   1056 mesh_poll(struct mesh_softc *sc, struct scsipi_xfer *xs)
   1057 {
   1058 	int count = xs->timeout;
   1059 
   1060 	while (count) {
   1061 		if (mesh_read_reg(sc, MESH_INTERRUPT))
   1062 			mesh_intr(sc);
   1063 
   1064 		if (xs->xs_status & XS_STS_DONE)
   1065 			return 0;
   1066 		delay(1000);
   1067 		count--;
   1068 	};
   1069 	return 1;
   1070 }
   1071 
   1072 void
   1073 mesh_done(struct mesh_softc *sc, struct mesh_scb *scb)
   1074 {
   1075 	struct scsipi_xfer *xs = scb->xs;
   1076 
   1077 	DPRINTF("mesh_done\n");
   1078 
   1079 	sc->sc_nextstate = MESH_BUSFREE;
   1080 	sc->sc_nexus = NULL;
   1081 
   1082 	callout_stop(&scb->xs->xs_callout);
   1083 
   1084 	if (scb->status == SCSI_BUSY) {
   1085 		xs->error = XS_BUSY;
   1086 		printf("Target busy\n");
   1087 	}
   1088 
   1089 	xs->status = scb->status;
   1090 	xs->resid = scb->resid;
   1091 	if (scb->status == SCSI_CHECK) {
   1092 		xs->error = XS_BUSY;
   1093 	}
   1094 
   1095 	mesh_set_reg(sc, MESH_SYNC_PARAM, 2);
   1096 
   1097 	if ((xs->xs_control & XS_CTL_POLL) == 0)
   1098 		mesh_sched(sc);
   1099 
   1100 	scsipi_done(xs);
   1101 	mesh_free_scb(sc, scb);
   1102 }
   1103 
   1104 void
   1105 mesh_timeout(void *arg)
   1106 {
   1107 	struct mesh_scb *scb = arg;
   1108 	struct mesh_softc *sc =
   1109 	    (void *)scb->xs->xs_periph->periph_channel->chan_adapter->adapt_dev;
   1110 	int s;
   1111 	int status0, status1;
   1112 	int intr, error, exception, imsk;
   1113 
   1114 	printf("%s: timeout state %d\n", sc->sc_dev.dv_xname, sc->sc_nextstate);
   1115 
   1116 	intr = mesh_read_reg(sc, MESH_INTERRUPT);
   1117 	imsk = mesh_read_reg(sc, MESH_INTR_MASK);
   1118 	exception = mesh_read_reg(sc, MESH_EXCEPTION);
   1119 	error = mesh_read_reg(sc, MESH_ERROR);
   1120 	status0 = mesh_read_reg(sc, MESH_BUS_STATUS0);
   1121 	status1 = mesh_read_reg(sc, MESH_BUS_STATUS1);
   1122 
   1123 	printf("%s: intr/msk %02x/%02x, exc %02x, err %02x, st0/1 %02x/%02x\n",
   1124 		sc->sc_dev.dv_xname,
   1125 		intr, imsk, exception, error, status0, status1);
   1126 
   1127 	s = splbio();
   1128 	if (sc->sc_flags & MESH_DMA_ACTIVE) {
   1129 		printf("mesh: resetting DMA\n");
   1130 		dbdma_reset(sc->sc_dmareg);
   1131 	}
   1132 	scb->xs->error = XS_TIMEOUT;
   1133 
   1134 	mesh_set_reg(sc, MESH_SEQUENCE, MESH_CMD_BUSFREE);
   1135 	sc->sc_nextstate = MESH_COMPLETE;
   1136 
   1137 	splx(s);
   1138 }
   1139 
   1140 void
   1141 mesh_minphys(struct buf *bp)
   1142 {
   1143 	if (bp->b_bcount > 64*1024)
   1144 		bp->b_bcount = 64*1024;
   1145 
   1146 	minphys(bp);
   1147 }
   1148