scsincr53c8xx.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

/*
 * NCR/Symbios/LSI Logic 53c8xx driver for Plan 9
 * Nigel Roles ([e-mail])
 *
 * 13/3/01	Fixed microcode to support targets > 7
 *
 * 01/12/00	Removed previous comments. Fixed a small problem in
 *			mismatch recovery for targets with synchronous offsets of >=16
 *			connected to >=875s. Thanks, Jean.
 *
 * Known problems
 *
 * Read/write mismatch recovery may fail on 53c1010s. Really need to get a manual.
*/

#define MAXTARGET	16		/* can be 8 or 16 */

/* Define one or the other ... */
//#define CPU
#ifndef FS
#define FS
#endif

#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#ifndef FS
#include "../port/error.h"
#endif

#include "ureg.h"
#ifdef NAINCLUDE
#include "na/na.h"
#include "na/nasupport.h"
#endif /* NAINCLUDE */

/**********************************/
/* Portable configuration macros  */
/**********************************/

//#define BOOTDEBUG
//#define SINGLE_TARGET
//#define ASYNC_ONLY
//#define	QUICK_TIMEOUT
//#define	INTERNAL_SCLK
//#define ALWAYS_DO_WDTR
#define WMR_DEBUG

/**********************************/
/* CPU specific macros            */
/**********************************/

#ifdef CPU
#ifdef BOOTDEBUG

#define KPRINT oprint
#define IPRINT iprint
#define DEBUG(n) 0
#define IFLUSH() iflush()

#else

#define KPRINT kprint
#define IPRINT kprint
#define DEBUG(n) scsidebugs[n]
#define IFLUSH()

#endif
#endif

/*******************************/
/* Fileserver specific defines */
/*******************************/
#ifdef FS
#define DEVICENAME "ncr53c8xx"
#define PRINTPREFIX DEVICENAME ": "
#define xalloc(n) ialloc(n, 1)
#define KADDR(a) ((void*)((ulong)(a)|KZERO))

#define KPRINT if(0)print
#define IPRINT if(0)print
#define DEBUG(n) 0
#define IFLUSH()
#endif

/*******************************/
/* General                     */
/*******************************/

#ifndef DMASEG
#define DMASEG(x) PADDR(x)
#define legetl(x) (*(ulong*)(x))
#define lesetl(x,v) (*(ulong*)(x) = (v))
#define swabl(a,b,c)
#define IRQBASE Int0vec
#else
#define IRQBASE (PCIvec + 5)
#endif
#define DMASEG_TO_KADDR(x) KADDR(PADDR(x))
#define KPTR(x) ((x) == 0 ? 0 : DMASEG_TO_KADDR(x))

#define MEGA 1000000L
#ifdef INTERNAL_SCLK
#define	SCLK (33 * MEGA)
#else
#define SCLK (40 * MEGA)
#endif
#define ULTRA_NOCLOCKDOUBLE_SCLK (80 * MEGA)

#define MAXSYNCSCSIRATE (5 * MEGA)
#define MAXFASTSYNCSCSIRATE (10 * MEGA)
#define MAXULTRASYNCSCSIRATE (20 * MEGA)
#define MAXULTRA2SYNCSCSIRATE (40 * MEGA)
#define MAXASYNCCORERATE (25 * MEGA)
#define MAXSYNCCORERATE (25 * MEGA)
#define MAXFASTSYNCCORERATE (50 * MEGA)
#define MAXULTRASYNCCORERATE (80 * MEGA)
#define MAXULTRA2SYNCCORERATE (160 * MEGA)


#define X_MSG	1
#define X_MSG_SDTR 1
#define X_MSG_WDTR 3

#ifndef NAINCLUDE
struct na_patch {
	unsigned lwoff;
	unsigned char type;
};
#endif /* NAINCLUDE */

extern int scsidebugs[];

typedef struct Ncr {
	uchar scntl0;	/* 00 */
	uchar scntl1;
	uchar scntl2;
	uchar scntl3;

	uchar scid;	/* 04 */
	uchar sxfer;
	uchar sdid;
	uchar gpreg;

	uchar sfbr;	/* 08 */
	uchar socl;
	uchar ssid;
	uchar sbcl;

	uchar dstat;	/* 0c */
	uchar sstat0;
	uchar sstat1;
	uchar sstat2;

	uchar dsa[4];	/* 10 */

	uchar istat;	/* 14 */
	uchar istatpad[3];

	uchar ctest0;	/* 18 */
	uchar ctest1;
	uchar ctest2;
	uchar ctest3;

	uchar temp[4];	/* 1c */

	uchar dfifo;	/* 20 */
	uchar ctest4;
	uchar ctest5;
	uchar ctest6;

	uchar dbc[3];	/* 24 */
	uchar dcmd;	/* 27 */

	uchar dnad[4];	/* 28 */
	uchar dsp[4];	/* 2c */
	uchar dsps[4];	/* 30 */

	uchar scratcha[4];	/* 34 */

	uchar dmode;	/* 38 */
	uchar dien;
	uchar dwt;
	uchar dcntl;

	uchar adder[4];	/* 3c */

	uchar sien0;	/* 40 */
	uchar sien1;
	uchar sist0;
	uchar sist1;

	uchar slpar;	/* 44 */
	uchar slparpad0;
	uchar macntl;
	uchar gpcntl;

	uchar stime0;	/* 48 */
	uchar stime1;
	uchar respid;
	uchar respidpad0;

	uchar stest0;	/* 4c */
	uchar stest1;
	uchar stest2;
	uchar stest3;

	uchar sidl;	/* 50 */
	uchar sidlpad[3];

	uchar sodl;	/* 54 */
	uchar sodlpad[3];

	uchar sbdl;	/* 58 */
	uchar sbdlpad[3];

	uchar scratchb[4];	/* 5c */
} Ncr;

typedef struct Movedata {
	uchar dbc[4];
	uchar pa[4];
} Movedata;

typedef enum NegoState {
	NeitherDone, WideInit, WideResponse, WideDone,
	SyncInit, SyncResponse, BothDone
} NegoState;

typedef enum State {
	Allocated, Queued, Active, Done
} State;

typedef struct Dsa {
	union {
		uchar state[4];
		struct {
			uchar stateb;
			uchar result;
			uchar dmablks;
			uchar flag;	/* setbyte(state,3,...) */
		};
	};

	union {
		ulong dmancr;		/* For block transfer: NCR order (little-endian) */
		uchar dmaaddr[4];
	};

	uchar target;			/* Target */
	uchar pad0[3];

	uchar lun;			/* Logical Unit Number */
	uchar pad1[3];

	uchar scntl3;
	uchar sxfer;
	uchar pad2[2];

	uchar next[4];			/* chaining for SCRIPT (NCR byte order) */
	struct Dsa *freechain;		/* chaining for freelist */
	Rendez;
	uchar scsi_id_buf[4];
	Movedata msg_out_buf;
	Movedata cmd_buf;
	Movedata data_buf;
	Movedata status_buf;
	uchar msg_out[10];		/* enough to include SDTR */
	uchar status;
	ushort p9status;
	uchar parityerror;
} Dsa;

typedef enum Feature {
	BigFifo = 1,			/* 536 byte fifo */
	BurstOpCodeFetch = 2,		/* burst fetch opcodes */
	Prefetch = 4,			/* prefetch 8 longwords */
	LocalRAM = 8,			/* 4K longwords of local RAM */
	Differential = 16,		/* Differential support */
	Wide = 32,			/* Wide capable */
	Ultra = 64,			/* Ultra capable */
	ClockDouble = 128,		/* Has clock doubler */
	ClockQuad = 256,		/* Has clock quadrupler (same as Ultra2) */
	Ultra2 = 256,
} Feature;

typedef enum Burst {
	Burst2 = 0,
	Burst4 = 1,
	Burst8 = 2,
	Burst16 = 3,
	Burst32 = 4,
	Burst64 = 5,
	Burst128 = 6
} Burst;

typedef struct Variant {
	ushort did;
	uchar maxrid;			/* maximum allowed revision ID */
	char *name;
	Burst burst;			/* codings for max burst */
	uchar maxsyncoff;		/* max synchronous offset - must be power of 2 */
	uchar registers;		/* number of 32 bit registers */
	unsigned feature;
} Variant;


static unsigned char cf2[] = { 6, 2, 3, 4, 6, 8, 12, 16 };
#define NULTRA2SCF (sizeof(cf2)/sizeof(cf2[0]))
#define NULTRASCF (NULTRA2SCF - 2)
#define NSCF (NULTRASCF - 1)

typedef struct Controller {
	Lock;
	struct {
		uchar scntl3;
		uchar stest2;
	} bios;
	int ctlrno;
	uchar synctab[NULTRA2SCF - 1][8];/* table of legal tpfs */
	NegoState s[MAXTARGET];
	uchar scntl3[MAXTARGET];
	uchar sxfer[MAXTARGET];
	uchar cap[MAXTARGET];		/* capabilities byte from Identify */
	ushort capvalid;		/* bit per target for validity of cap[] */
	ushort wide;			/* bit per target set if wide negotiated */
	ulong sclk;			/* clock speed of controller */
	uchar clockmult;		/* set by synctabinit */
	uchar ccf;			/* CCF bits */
	uchar tpf;			/* best tpf value for this controller */
	uchar feature;			/* requested features */
	int running;			/* is the script processor running? */
	int ssm;			/* single step mode */
	Ncr *n;				/* pointer to registers */
	Variant *v;			/* pointer to variant type */
	ulong *script;			/* where the real script is */
	ulong scriptpa;			/* where the real script is */

	struct {
		Lock;
		uchar head[4];		/* head of free list (NCR byte order) */
		Dsa	*tail;
		Dsa	*freechain;
	} dsalist;

	QLock q[MAXTARGET];		/* queues for each target */
} Controller;

#define SYNCOFFMASK(c)		(((c)->v->maxsyncoff * 2) - 1)
#define SSIDMASK(c)		(((c)->v->feature & Wide) ? 15 : 7)

static Controller *ctlrxx[MaxScsi];

/* ISTAT */
enum { Abrt = 0x80, Srst = 0x40, Sigp = 0x20, Sem = 0x10, Con = 0x08, Intf = 0x04, Sip = 0x02, Dip = 0x01 };

/* DSTAT */
enum { Dfe = 0x80, Mdpe = 0x40, Bf = 0x20, Abrted = 0x10, Ssi = 0x08, Sir = 0x04, Iid = 0x01 };

/* SSTAT */
enum { DataOut, DataIn, Cmd, Status, ReservedOut, ReservedIn, MessageOut, MessageIn };

#define STATUS_COMPLETE 0x6000
#define STATUS_FAIL 0x8000
#define STATUS_SELECTION_TIMEOUT 0x0200

static void setmovedata(Movedata*, ulong, ulong);
static void advancedata(Movedata*, long);
static int bios_set_differential(Controller *c);

static char *phase[] = {
	"data out", "data in", "command", "status",
	"reserved out", "reserved in", "message out", "message in"
};

#ifdef BOOTDEBUG
#define DEBUGSIZE 10240
char debugbuf[DEBUGSIZE];
char *debuglast;

void
iprint(char *format, ...)
{
	if (debuglast == 0)
		debuglast = debugbuf;
	debuglast = doprint(debuglast, debugbuf + (DEBUGSIZE - 1), format, (&format + 1));
}

void
iflush()
{
	int s;
	char *endp;
	s = splhi();
	if (debuglast == 0)
		debuglast = debugbuf;
	if (debuglast == debugbuf) {
		splx(s);
		return;
	}
	endp = debuglast;
	splx(s);
	screenputs(debugbuf, endp - debugbuf);
	s = splhi();
	memmove(debugbuf, endp, debuglast - endp);
	debuglast -= endp - debugbuf;
	splx(s);
}

void
oprint(char *format, ...)
{
	int s;

	iflush();
	s = splhi();
	if (debuglast == 0)
		debuglast = debugbuf;
	debuglast = doprint(debuglast, debugbuf + (DEBUGSIZE - 1), format, (&format + 1));
	splx(s);
	iflush();
}
#endif

#include "script.i"

static Dsa *
dsaalloc(Controller *c, int target, int lun)
{
	Dsa *d;

	ilock(&c->dsalist);
	if ((d = c->dsalist.freechain) == 0) {
		d = xalloc(sizeof(*d));
		if (DEBUG(1))
			KPRINT(PRINTPREFIX "%d/%d: allocated new dsa %lux\n", target, lun, (ulong)d);
		lesetl(d->next, 0);
		lesetl(d->state, A_STATE_ALLOCATED);
		if (legetl(c->dsalist.head) == 0)
			lesetl(c->dsalist.head, DMASEG(d));	/* ATOMIC?!? */
		else
			lesetl(c->dsalist.tail->next, DMASEG(d));	/* ATOMIC?!? */
		c->dsalist.tail = d;
	}
	else {
		if (DEBUG(1))
			KPRINT(PRINTPREFIX "%d/%d: reused dsa %lux\n", target, lun, (ulong)d);
		c->dsalist.freechain = d->freechain;
		lesetl(d->state, A_STATE_ALLOCATED);
	}
	iunlock(&c->dsalist);
	d->target = target;
	d->lun = lun;
	return d;
}

static void
dsafree(Controller *c, Dsa *d)
{
	ilock(&c->dsalist);
	d->freechain = c->dsalist.freechain;
	c->dsalist.freechain = d;
	lesetl(d->state, A_STATE_FREE);
	iunlock(&c->dsalist);
}

static Dsa *
dsafind(Controller *c, uchar target, uchar lun, uchar state)
{
	Dsa *d;
	for (d = KPTR(legetl(c->dsalist.head)); d; d = KPTR(legetl(d->next))) {
		if (d->target != 0xff && d->target != target)
			continue;
		if (lun != 0xff && d->lun != lun)
			continue;
		if (state != 0xff && d->stateb != state)
			continue;
		break;
	}
	return d;
}

static void
dumpncrregs(Controller *c, int intr)
{
	int i;
	Ncr *n = c->n;
	int depth = c->v->registers / 4;

	KPRINT("sa = %.8lux\n", c->scriptpa);
	for (i = 0; i < depth; i++) {
		int j;
		for (j = 0; j < 4; j++) {
			int k = j * depth + i;
			uchar *p;

			/* display little-endian to make 32-bit values readable */
			p = (uchar*)n+k*4;
			if (intr)
				IPRINT(" %.2x%.2x%.2x%.2x %.2x %.2x", p[3], p[2], p[1], p[0], k * 4, (k * 4) + 0x80);
			else
				KPRINT(" %.2x%.2x%.2x%.2x %.2x %.2x", p[3], p[2], p[1], p[0], k * 4, (k * 4) + 0x80);
			USED(p);
		}
		if (intr)
			IPRINT("\n");
		else
			KPRINT("\n");
	}
}

static int
chooserate(Controller *c, int tpf, int *scfp, int *xferpp)
{
	/* find lowest entry >= tpf */
	int besttpf = 1000;
	int bestscfi = 0;
	int bestxferp = 0;
	int scf, xferp;
	int maxscf;

	if (c->v->feature & Ultra2)
		maxscf = NULTRA2SCF;
	else if (c->v->feature & Ultra)
		maxscf = NULTRASCF;
	else
		maxscf = NSCF;

	/*
	 * search large clock factors first since this should
	 * result in more reliable transfers
	 */
	for (scf = maxscf; scf >= 1; scf--) {
		for (xferp = 0; xferp < 8; xferp++) {
			unsigned char v = c->synctab[scf - 1][xferp];
			if (v == 0)
				continue;
			if (v >= tpf && v < besttpf) {
				besttpf = v;
				bestscfi = scf;
				bestxferp = xferp;
			}
		}
	}
	if (besttpf == 1000)
		return 0;
	if (scfp)
		*scfp = bestscfi;
	if (xferpp)
		*xferpp = bestxferp;
	return besttpf;
}