sdata.c

著名操作系统Plan 9的第三版的部分核心源代码。现在很难找到了。Plan 9是bell实验室开发的Unix后继者。

	int count, lba, len;

	/*
	 * Map SCSI commands into ATA commands for discs.
	 * Fail any command with a LUN except INQUIRY which
	 * will return 'logical unit not supported'.
	 */
	if((cmd[1]>>5) && cmd[0] != 0x12)
		return atasetsense(drive, SDcheck, 0x05, 0x25, 0);

	switch(cmd[0]){
	default:
		return atasetsense(drive, SDcheck, 0x05, 0x20, 0);

	case 0x00:			/* test unit ready */
		return SDok;

	case 0x03:			/* request sense */
		if(cmd[4] < sizeof(drive->sense))
			len = cmd[4];
		else
			len = sizeof(drive->sense);
		if(drive->data && drive->dlen >= len){
			memmove(drive->data, drive->sense, len);
			drive->data += len;
		}
		return SDok;

	case 0x12:			/* inquiry */
		if(cmd[4] < sizeof(drive->inquiry))
			len = cmd[4];
		else
			len = sizeof(drive->inquiry);
		if(drive->data && drive->dlen >= len){
			memmove(drive->data, drive->inquiry, len);
			drive->data += len;
		}
		return SDok;

	case 0x1B:			/* start/stop unit */
		/*
		 * NOP for now, can use the power management feature
		 * set later.
		 */
		return SDok;

	case 0x25:			/* read capacity */
		if((cmd[1] & 0x01) || cmd[2] || cmd[3])
			return atasetsense(drive, SDcheck, 0x05, 0x24, 0);
		if(drive->data == nil || drive->dlen < 8)
			return atasetsense(drive, SDcheck, 0x05, 0x20, 1);
		/*
		 * Read capacity returns the LBA of the last sector.
		 */
		len = drive->sectors-1;
		p = drive->data;
		*p++ = len>>24;
		*p++ = len>>16;
		*p++ = len>>8;
		*p++ = len;
		len = drive->secsize;
		*p++ = len>>24;
		*p++ = len>>16;
		*p++ = len>>8;
		*p = len;
		drive->data += 8;
		return SDok;

	case 0x28:			/* read */
	case 0x2A:			/* write */
		break;

	case 0x5A:
		return atamodesense(drive, cmd);
	}

	ctlr = drive->ctlr;
	lba = (cmd[2]<<24)|(cmd[3]<<16)|(cmd[4]<<8)|cmd[5];
	count = (cmd[7]<<8)|cmd[8];
	if(drive->data == nil)
		return SDok;
	if(drive->dlen < count*drive->secsize)
		count = drive->dlen/drive->secsize;
	qlock(ctlr);
	while(count){
		if(count > 256)
			drive->count = 256;
		else
			drive->count = count;
		if(atageniostart(drive, lba)){
			ilock(ctlr);
			atanop(drive, 0);
			iunlock(ctlr);
			qunlock(ctlr);
			return atagenioretry(drive);
		}

		while(waserror())
			;
		tsleep(ctlr, atageniodone, ctlr, 10*1000);
		poperror();
		if(!ctlr->done){
			/*
			 * What should the above timeout be? In
			 * standby and sleep modes it could take as
			 * long as 30 seconds for a drive to respond.
			 * Very hard to get out of this cleanly.
			 */
			atadumpstate(drive, cmd, lba, count);
			ataabort(drive, 1);
			return atagenioretry(drive);
		}

		if(drive->status & Err){
			qunlock(ctlr);
			return atasetsense(drive, SDcheck, 4, 8, drive->error);
		}
		count -= drive->count;
		lba += drive->count;
	}
	qunlock(ctlr);

	return SDok;
}

static int
atario(SDreq* r)
{
	Ctlr *ctlr;
	Drive *drive;
	SDunit *unit;
	uchar cmd10[10], *cmdp, *p;
	int clen, reqstatus, status;

	unit = r->unit;
	if((ctlr = unit->dev->ctlr) == nil || ctlr->drive[unit->subno] == nil){
		r->status = SDtimeout;
		return SDtimeout;
	}
	drive = ctlr->drive[unit->subno];

	/*
	 * Most SCSI commands can be passed unchanged except for
	 * the padding on the end. The few which require munging
	 * are not used internally. Mode select/sense(6) could be
	 * converted to the 10-byte form but it's not worth the
	 * effort. Read/write(6) are easy.
	 */
	switch(r->cmd[0]){
	case 0x08:			/* read */
	case 0x0A:			/* write */
		cmdp = cmd10;
		memset(cmdp, 0, sizeof(cmd10));
		cmdp[0] = r->cmd[0]|0x20;
		cmdp[1] = r->cmd[1] & 0xE0;
		cmdp[5] = r->cmd[3];
		cmdp[4] = r->cmd[2];
		cmdp[3] = r->cmd[1] & 0x0F;
		cmdp[8] = r->cmd[4];
		clen = sizeof(cmd10);
		break;

	default:
		cmdp = r->cmd;
		clen = r->clen;
		break;
	}

	qlock(drive);
retry:
	drive->write = r->write;
	drive->data = r->data;
	drive->dlen = r->dlen;

	drive->status = 0;
	drive->error = 0;
	if(drive->pkt)
		status = atapktio(drive, cmdp, clen);
	else
		status = atagenio(drive, cmdp, clen);
	if(status == SDretry){
		if(DbgDEBUG)
			print("%s: retry: dma %8.8uX rwm %4.4uX\n",
				unit->name, drive->dmactl, drive->rwmctl);
		goto retry;
	}
	if(status == SDok){
		atasetsense(drive, SDok, 0, 0, 0);
		if(drive->data){
			p = r->data;
			r->rlen = drive->data - p;
		}
		else
			r->rlen = 0;
	}
	else if(status == SDcheck && !(r->flags & SDnosense)){
		drive->write = 0;
		memset(cmd10, 0, sizeof(cmd10));
		cmd10[0] = 0x03;
		cmd10[1] = r->lun<<5;
		cmd10[4] = sizeof(r->sense)-1;
		drive->data = r->sense;
		drive->dlen = sizeof(r->sense)-1;
		drive->status = 0;
		drive->error = 0;
		if(drive->pkt)
			reqstatus = atapktio(drive, cmd10, 6);
		else
			reqstatus = atagenio(drive, cmd10, 6);
		if(reqstatus == SDok){
			r->flags |= SDvalidsense;
			atasetsense(drive, SDok, 0, 0, 0);
		}
	}
	qunlock(drive);
	r->status = status;
	if(status != SDok)
		return status;

	/*
	 * Fix up any results.
	 * Many ATAPI CD-ROMs ignore the LUN field completely and
	 * return valid INQUIRY data. Patch the response to indicate
	 * 'logical unit not supported' if the LUN is non-zero.
	 */
	switch(cmdp[0]){
	case 0x12:			/* inquiry */
		if((p = r->data) == nil)
			break;
		if((cmdp[1]>>5) && (!drive->pkt || (p[0] & 0x1F) == 0x05))
			p[0] = 0x7F;
		/*FALLTHROUGH*/
	default:
		break;
	}

	return SDok;
}

static void
atainterrupt(Ureg*, void* arg)
{
	Ctlr *ctlr;
	Drive *drive;
	int cmdport, len, status;

	ctlr = arg;

	ilock(ctlr);
	if(inb(ctlr->ctlport+As) & Bsy){
		iunlock(ctlr);
		if(DEBUG & DbgDEBUG)
			print("IBsy+");
		return;
	}
	cmdport = ctlr->cmdport;
	status = inb(cmdport+Status);
	if((drive = ctlr->curdrive) == nil){
		iunlock(ctlr);
		if((DEBUG & DbgDEBUG) && ctlr->command != Cedd)
			print("Inil%2.2uX+", ctlr->command);
		return;
	}

	if(status & Err)
		drive->error = inb(cmdport+Error);
	else switch(drive->command){
	default:
		drive->error = Abrt;
		break;

	case Crs:
	case Crsm:
		if(!(status & Drq)){
			drive->error = Abrt;
			break;
		}
		len = drive->block;
		if(drive->data+len > drive->limit)
			len = drive->limit-drive->data;
		inss(cmdport+Data, drive->data, len/2);
		drive->data += len;
		if(drive->data >= drive->limit)
			ctlr->done = 1;
		break;

	case Cws:
	case Cwsm:
		len = drive->block;
		if(drive->data+len > drive->limit)
			len = drive->limit-drive->data;
		drive->data += len;
		if(drive->data >= drive->limit){
			ctlr->done = 1;
			break;
		}
		if(!(status & Drq)){
			drive->error = Abrt;
			break;
		}
		len = drive->block;
		if(drive->data+len > drive->limit)
			len = drive->limit-drive->data;
		outss(cmdport+Data, drive->data, len/2);
		break;

	case Cpkt:
		atapktinterrupt(drive);
		break;

	case Crd:
	case Cwd:
		atadmainterrupt(drive, drive->count*drive->secsize);
		break;
	}
	iunlock(ctlr);

	if(drive->error){
		status |= Err;
		ctlr->done = 1;
	}

	if(ctlr->done){
		ctlr->curdrive = nil;
		drive->status = status;
		wakeup(ctlr);
	}
}

static SDev*
atapnp(void)
{
	Ctlr *ctlr;
	Pcidev *p;
	int channel, ispc87415, pi, r;
	SDev *legacy[2], *sdev, *head, *tail;

	legacy[0] = legacy[1] = head = tail = nil;
	if(sdev = ataprobe(0x1F0, 0x3F4, IrqATA0)){
		head = tail = sdev;
		legacy[0] = sdev;
	}
	if(sdev = ataprobe(0x170, 0x374, IrqATA1)){
		if(head != nil)
			tail->next = sdev;
		else
			head = sdev;
		tail = sdev;
		legacy[1] = sdev;
	}

	p = nil;
	while(p = pcimatch(p, 0, 0)){
		/*
		 * Look for devices with the correct class and sub-class
		 * code and known device and vendor ID; add native-mode
		 * channels to the list to be probed, save info for the
		 * compatibility mode channels.
		 * Note that the legacy devices should not be considered
		 * PCI devices by the interrupt controller.
		 * For both native and legacy, save info for busmastering
		 * if capable.
		 * Promise Ultra ATA/66 (PDC20262) appears to
		 * 1) give a sub-class of 'other mass storage controller'
		 *    instead of 'IDE controller', regardless of whether it's
		 *    the only controller or not;
		 * 2) put 0 in the programming interface byte (probably
		 *    as a consequence of 1) above).
		 */
		if(p->ccrb != 0x01 || (p->ccru != 0x01 && p->ccru != 0x80))
			continue;
		pi = p->ccrp;
		ispc87415 = 0;

		switch((p->did<<16)|p->vid){
		default:
			continue;

		case (0x0002<<16)|0x100B:	/* NS PC87415 */
			/*
			 * Disable interrupts on both channels until
			 * after they are probed for drives.
			 * This must be called before interrupts are
			 * enabled because the IRQ may be shared.
			 */
			ispc87415 = 1;
			pcicfgw32(p, 0x40, 0x00000300);
			break;
		case (0x1000<<16)|0x1042:	/* PC-Tech RZ1000 */
			/*
			 * Turn off prefetch. Overkill, but cheap.
			 */
			r = pcicfgr32(p, 0x40);
			r &= ~0x2000;
			pcicfgw32(p, 0x40, r);
			break;
		case (0x4D38<<16)|0x105A:	/* Promise PDC20262 */
			pi = 0x85;
			break;
		case (0x0640<<16)|0x1095:	/* CMD 640B */
			/*
			 * Bugfix code here...
			 */
			break;
		case (0x0646<<16)|0x1095:	/* CMD 646 */
		case (0x0571<<16)|0x1106:	/* VIA 82C686 */
		case (0x1230<<16)|0x8086:	/* 82371FB (PIIX) */
		case (0x7010<<16)|0x8086:	/* 82371SB (PIIX3) */
		case (0x7111<<16)|0x8086:	/* 82371[AE]B (PIIX4[E]) */
			break;
		}

		for(channel = 0; channel < 2; channel++){
			if(pi & (1<<(2*channel))){
				sdev = ataprobe(p->mem[0+2*channel].bar & ~0x01,
						p->mem[1+2*channel].bar & ~0x01,
						p->intl);
				if(sdev == nil)
					continue;

				ctlr = sdev->ctlr;
				if(ispc87415)
					ctlr->ienable = pc87415ienable;

				if(head != nil)
					tail->next = sdev;
				else
					head = sdev;
				tail = sdev;
				ctlr->tbdf = p->tbdf;
			}
			else if((sdev = legacy[channel]) == nil)
				continue;
			else
				ctlr = sdev->ctlr;

			ctlr->pcidev = p;
			if(!(pi & 0x80))
				continue;
			ctlr->bmiba = (p->mem[4].bar & ~0x01) + channel*8;
		}
	}

	return head;
}

static SDev*
atalegacy(int port, int irq)
{
	return ataprobe(port, port+0x204, irq);
}

static SDev*
ataid(SDev* sdev)
{
	int i;
	Ctlr *ctlr;

	/*
	 * Legacy controllers are always 'C' and 'D' and if
	 * they exist and have drives will be first in the list.
	 * If there are no active legacy controllers, native
	 * controllers start at 'C'.
	 */
	if(sdev == nil)
		return nil;
	ctlr = sdev->ctlr;
	if(ctlr->cmdport == 0x1F0 || ctlr->cmdport == 0x170)
		i = 2;
	else
		i = 0;
	while(sdev){
		if(sdev->ifc == &sdataifc){
			ctlr = sdev->ctlr;
			if(ctlr->cmdport == 0x1F0)
				sdev->idno = 'C';
			else if(ctlr->cmdport == 0x170)
				sdev->idno = 'D';
			else{
				sdev->idno = 'C'+i;
				i++;
			}
			snprint(sdev->name, NAMELEN, "sd%c", sdev->idno);
		}
		sdev = sdev->next;
	}

	return nil;
}

static int
ataenable(SDev* sdev)
{
	Ctlr *ctlr;
	char name[NAMELEN];

	ctlr = sdev->ctlr;

	if(ctlr->bmiba){
		if(ctlr->pcidev != nil)
			pcisetbme(ctlr->pcidev);
		ctlr->prdt = xspanalloc(Nprd*sizeof(Prd), 4, 4*1024);
	}
	snprint(name, NAMELEN, "%s (%s)", sdev->name, sdev->ifc->name);
	intrenable(ctlr->irq, atainterrupt, ctlr, ctlr->tbdf, name);
	outb(ctlr->ctlport+Dc, 0);
	if(ctlr->ienable)
		ctlr->ienable(ctlr);

	return 1;
}

static int
atarctl(SDunit* unit, char* p, int l)
{
	int n;
	Ctlr *ctlr;
	Drive *drive;

	if((ctlr = unit->dev->ctlr) == nil || ctlr->drive[unit->subno] == nil)
		return 0;
	drive = ctlr->drive[unit->subno];

	qlock(drive);
	n = snprint(p, l, "config %4.4uX capabilities %4.4uX",
		drive->info[Iconfig], drive->info[Icapabilities]);
	if(drive->dma)
		n += snprint(p+n, l-n, " dma %8.8uX dmactl %8.8uX",
			drive->dma, drive->dmactl);
	if(drive->rwm)
		n += snprint(p+n, l-n, " rwm %ud rwmctl %ud",
			drive->rwm, drive->rwmctl);
	n += snprint(p+n, l-n, "\n");
	if(!unit->changed && unit->sectors){
		n += snprint(p+n, l-n, "geometry %ld %ld",
			unit->sectors, unit->secsize);
		if(drive->pkt == 0)
			n += snprint(p+n, l-n, " %d %d %d",
				drive->c, drive->h, drive->s);
		n += snprint(p+n, l-n, "\n");
	}
	qunlock(drive);

	return n;
}

static int
atawctl(SDunit* unit, Cmdbuf* cb)
{
	Ctlr *ctlr;
	Drive *drive;

	if((ctlr = unit->dev->ctlr) == nil || ctlr->drive[unit->subno] == nil)
		return 0;
	drive = ctlr->drive[unit->subno];

	qlock(drive);
	if(waserror()){
		qunlock(drive);
		nexterror();
	}

	/*
	 * Dma and rwm control is passive at the moment,
	 * i.e. it is assumed that the hardware is set up
	 * correctly already either by the BIOS or when
	 * the drive was initially identified.
	 */
	if(strcmp(cb->f[0], "dma") == 0){
		if(cb->nf != 2 || drive->dma == 0)
			error(Ebadctl);
		if(strcmp(cb->f[1], "on") == 0)
			drive->dmactl = drive->dma;
		else if(strcmp(cb->f[1], "off") == 0)
			drive->dmactl = 0;
		else
			error(Ebadctl);
	}
	else if(strcmp(cb->f[0], "rwm") == 0){
		if(cb->nf != 2 || drive->rwm == 0)
			error(Ebadctl);
		if(strcmp(cb->f[1], "on") == 0)
			drive->rwmctl = drive->rwm;
		else if(strcmp(cb->f[1], "off") == 0)
			drive->rwmctl = 0;
		else
			error(Ebadctl);
	}
	else
		error(Ebadctl);
	qunlock(drive);
	poperror();

	return 0;
}

SDifc sdataifc = {
	"ata",				/* name */

	atapnp,				/* pnp */
	atalegacy,			/* legacy */
	ataid,				/* id */
	ataenable,			/* enable */
	nil,				/* disable */

	scsiverify,			/* verify */
	scsionline,			/* online */
	atario,				/* rio */
	atarctl,			/* rctl */
	atawctl,			/* wctl */

	scsibio,			/* bio */
};