#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "ureg.h"
#include "../port/error.h"

enum {
	Ninq		= 255,
	Nscratch	= 255,

	CMDtest		= 0x00,
	CMDreqsense	= 0x03,
	CMDinquire	= 0x12,
	CMDstart	= 0x1B,
	CMDcapacity	= 0x25,
	CMDread10	= 0x28,
	CMDwrite10	= 0x2A,
};

typedef struct {
	ISAConf;
	Scsiio	io;

	Target	target[NTarget];
} Ctlr;

static Ctlr* scsi[MaxScsi];

extern SCSIdev* scsidev[];

void
scsireset(void)
{
	Ctlr *ctlr;
	int ctlrno, i, t;

	for(ctlr = 0, ctlrno = 0; ctlrno < MaxScsi; ctlrno++){
		if(ctlr == 0)
			ctlr = malloc(sizeof(Ctlr));
		memset(ctlr, 0, sizeof(Ctlr));
		if(isaconfig("scsi", ctlrno, ctlr) == 0)
			continue;
		for(i = 0; scsidev[i]; i++){
			if(cistrcmp(ctlr->type, scsidev[i]->type))
				continue;
			if((ctlr->io = scsidev[i]->reset(ctlrno, ctlr)) == 0)
				break;

			print("scsi#%d: %s: port 0x%luX irq %lud",
				ctlrno, ctlr->type, ctlr->port,
				ctlr->irq);
			if(ctlr->mem)
				print(" addr 0x%luX", PADDR(ctlr->mem));
			if(ctlr->size)
				print(" size 0x%luX", ctlr->size);
			print("\n");

			for(t = 0; t < NTarget; t++){
				ctlr->target[t].ctlrno = ctlrno;
				ctlr->target[t].target = t;
				ctlr->target[t].inq = xalloc(Ninq);
				ctlr->target[t].scratch = xalloc(Nscratch);
			}

			scsi[ctlrno] = ctlr;
			ctlr = 0;
			break;
		}
	}
	if(ctlr)
		free(ctlr);
}

static uchar lastcmd[16];
static int lastcmdsz;

int
scsiexec(Target *t, int rw, uchar *cmd, int cbytes, void *data, int *dbytes)
{
	int s;

	/*
	 * Call the device-specific I/O routine.
	 * There should be no calls to 'error()' below this
	 * which percolate back up.
	 */
	switch(s = scsi[t->ctlrno]->io(t, rw, cmd, cbytes, data, dbytes)){

	case STcheck:
		memmove(lastcmd, cmd, cbytes);
		lastcmdsz = cbytes;
		/*FALLTHROUGH*/

	default:
		/*
		 * It's more complicated than this. There are conditions
		 * which are 'ok' but for which the returned status code
		 * is not 'STok'.
		 * Also, not all conditions require a reqsense, might
		 * need to do a reqsense here and make it available to the
		 * caller somehow.
		 *
		 * Later.
		 */
		break;
	}

	return s;
}

Target*
scsiunit(int ctlr, int unit)
{
	Target *t;

	if(ctlr < 0 || ctlr >= MaxScsi || scsi[ctlr] == 0)
		return 0;
	if(unit < 0 || unit >= NTarget)
		return 0;
	t = &scsi[ctlr]->target[unit];
	if(t->ok == 0)
		return 0;
	return t;
}

static void
scsiprobe(Ctlr *ctlr)
{
	Target *t;
	int i, s, nbytes;

	for(i = 0; i < NTarget; i++) {
		t = &ctlr->target[i];

		if(scsitest(t, 0) < 0)
			continue;

		/*
		 * Determine if the drive exists and is not ready or
		 * is simply not responding
		 */
		nbytes = Nscratch;
		s = scsireqsense(t, 0, t->scratch, &nbytes, 0);
		if(s != STok){
			print("scsi#%d: unit %d unavailable, status %d\n",
				t->ctlrno, i, s);
			continue;
		}

		/*
		 * Inquire to find out what the device is.
		 * Drivers then use the result to attach to targets
		 */
		memset(t->inq, 0, Ninq);
		nbytes = Ninq;
		s = scsiinquiry(t, 0, t->inq, &nbytes);
		if(s != STok) {
			print("scsi#%d: unit %d inquire failed, status %d\n",
				t->ctlrno, i, s);
			continue;
		}
		print("scsi#%d: unit %d: %s\n",
			t->ctlrno, i, (char*)(t->inq+8));
		t->ok = 1;
	}
}

static void
inventory(void)
{
	int i;
	static Lock ilock;
	static int inited;

	lock(&ilock);
	if(inited) {
		unlock(&ilock);
		return;
	}
	inited = 1;
	unlock(&ilock);

	for(i = 0; i < MaxScsi; i++){
		if(scsi[i])
			scsiprobe(scsi[i]);
	}
}

int
scsiinv(int devno, int *type, Target **rt, uchar **inq, char *id)
{
	Target *t;
	int ctlr, *i, unit;

	inventory();

	for(;;){
		ctlr = devno/NTarget;
		unit = devno%NTarget;
		if(ctlr >= MaxScsi || scsi[ctlr] == 0)
			return -1;

		t = &scsi[ctlr]->target[unit];
		devno++;
		if(t->ok){
			for(i = type; *i >= 0; i++){
				if((t->inq[0]&0x1F) != *i)
					continue;
				*rt = t;
				*inq = t->inq;
				if(id)
					sprint(id, "scsi%d: unit %d",
						ctlr, unit);
				return devno;
			}
		}
	}
	return -1;
}

int
scsitest(Target *t, int lun)
{
	uchar cmd[6];

	memset(cmd, 0, sizeof(cmd));
	cmd[0] = CMDtest;
	cmd[1] = lun<<5;
	return scsiexec(t, SCSIread, cmd, sizeof(cmd), 0, 0);
}

int
scsistart(Target *t, int lun, int s)
{
	uchar cmd[6];

	memset(cmd, 0, sizeof cmd);
	cmd[0] = CMDstart;
	cmd[1] = lun<<5;
	cmd[4] = s? 1: 0;
	return scsiexec(t, SCSIread, cmd, sizeof(cmd), 0, 0);
}

int
scsiinquiry(Target *t, int lun, void *data, int *datalen)
{
	uchar cmd[6];

	memset(cmd, 0, sizeof cmd);
	cmd[0] = CMDinquire;
	cmd[1] = lun<<5;
	cmd[4] = *datalen;
	return scsiexec(t, SCSIread, cmd, sizeof(cmd), data, datalen);
}

int
scsicap(Target *t, int lun, ulong *size, ulong *bsize)
{
	int s, nbytes;
	uchar cmd[10], *d;

	memset(cmd, 0, sizeof(cmd));
	cmd[0] = CMDcapacity;
	cmd[1] = lun<<5;

	nbytes = 8;
	d = scsialloc(nbytes);
	if(d == 0)
		return scsierrstr(STnomem);

	s = scsiexec(t, SCSIread, cmd, sizeof(cmd), d, &nbytes);
	if(s == STok) {
		*size = (d[0]<<24)|(d[1]<<16)|(d[2]<<8)|d[3];
		*bsize = (d[4]<<24)|(d[5]<<16)|(d[6]<<8)|d[7];
	}
	scsifree(d);
	return s;
}

int
scsibio(Target *t, int lun, int dir, void *b, long n, long bsize, long bno)
{
	uchar cmd[10];
	int s, cdbsiz, nbytes;

	cmd[0] = CMDwrite10;
	if(dir == SCSIread)
		cmd[0] = CMDread10;
	cmd[1] = (lun<<5);
	cmd[2] = bno>>24;
	cmd[3] = bno>>16;
	cmd[4] = bno>>8;
	cmd[5] = bno;
	cmd[6] = 0;
	cmd[7] = n>>8;
	cmd[8] = n;
	cmd[9] = 0;
	cdbsiz = 10;

	nbytes = n*bsize;
	s = scsiexec(t, dir, cmd, cdbsiz, b, &nbytes);
	if(s != STok) {
		nbytes = Nscratch;
		scsireqsense(t, lun, t->scratch, &nbytes, 0);
		return scsierrstr(s);
	}
	return nbytes;
}

static char *key[] =
{
	"no sense",
	"recovered error",
	"not ready",
	"medium error",
	"hardware error",
	"illegal request",
	"unit attention",
	"data protect",
	"blank check",
	"vendor specific",
	"copy aborted",
	"aborted command",
	"equal",
	"volume overflow",
	"miscompare",
	"reserved"
};

int
scsireqsense(Target *t, int lun, void *data, int *nbytes, int quiet)
{
	char *s;
	int n, status, try;
	uchar cmd[6], *sense;

	n = *nbytes;
	sense = malloc(n);

	for(try = 0; try < 20; try++) {
		memset(cmd, 0, sizeof(cmd));
		cmd[0] = CMDreqsense;
		cmd[1] = lun<<5;
		cmd[4] = n;
		memset(sense, 0, n);

		*nbytes = n;
		status = scsiexec(t, SCSIread, cmd, sizeof(cmd), sense, nbytes);
		if(status != STok){
			free(sense);
			return status;
		}
		*nbytes = sense[0x07]+8;
		memmove(data, sense, *nbytes);

		switch(sense[2] & 0x0F){

		case 6:					/* unit attention */
			/*
			 * 0x28 - not ready to ready transition,
			 *	  medium may have changed.
			 * 0x29 - power on, RESET or BUS DEVICE RESET occurred.
			 */
			if(sense[12] != 0x28 && sense[12] != 0x29)
				goto buggery;
			/*FALLTHROUGH*/
		case 0:					/* no sense */
		case 1:					/* recovered error */
			free(sense);
			return STok;

		case 2:					/* not ready */
			if(sense[12] == 0x3A)		/* medium not present */
				goto buggery;
			/*FALLTHROUGH*/

		default:
			/*
			 * If unit is becoming ready, rather than not ready,
			 * then wait a little then poke it again; should this
			 * be here or in the caller?
			 */
			if((sense[12] == 0x04 && sense[13] == 0x01)){
				while(waserror())
					;
				tsleep(&t->rendez, return0, 0, 500);
				poperror();
				scsitest(t, lun);
				break;
			}
			goto buggery;
		}
	}

buggery:
	if(quiet == 0){
		s = key[sense[2]&0x0F];
		print("scsi#%d: unit %d reqsense: '%s' code #%2.2ux #%2.2ux\n",
			t->ctlrno, t->target, s, sense[12], sense[13]);
		print("scsi#%d: byte 2: #%2.2uX, bytes 15-17: #%2.2uX #%2.2uX #%2.2uX\n",
			t->ctlrno, sense[2], sense[15], sense[16], sense[17]);
		print("lastcmd (%d): ", lastcmdsz);
		for(n = 0; n < lastcmdsz; n++)
			print(" #%2.2uX", lastcmd[n]);
		print("\n");
	}
	free(sense);
	return STcheck;
}


int
scsierrstr(int errno)
{
	char *p;

	switch(errno){
	case STnomem:
		p = Enomem;
		break;
	case STtimeout:
		p = "bus timeout";
		break;
	case STownid:
		p = "playing with myself";
		break;
	case STharderr:
		p = Eio;
		break;
	case STok:
		p = Enoerror;
		break;
	case STcheck:
		p = "check condition";
		break;
	case STcondmet:
		p = "condition met/good";
		break;
	case STbusy:
		p = "busy";
		break;
	case STintok:
		p = "intermediate/good";
		break;
	case STintcondmet:
		p = "intermediate/condition met/good";
		break;
	case STresconf:
		p = "reservation conflict";
		break;
	case STterminated:
		p = "command terminated";
		break;
	case STqfull:
		p = "queue full";
		break;

	default:
		p = "unknown SCSI error";
		break;
	}
	strncpy(up->error, p, NAMELEN);

	return -1;
}