io.h

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

/*
 *  programmable interrupt vectors (for the 8259's)
 */
enum
{
	Bptvec=		3,		/* breakpoints */
	Mathemuvec=	7,		/* math coprocessor emulation interrupt */
	Mathovervec=	9,		/* math coprocessor overrun interrupt */
	Matherr1vec=	16,		/* math coprocessor error interrupt */
	Faultvec=	14,		/* page fault */

	Int0vec=	24,		/* first 8259 */
	 Clockvec=	Int0vec+0,	/*  clock interrupts */
	 Kbdvec=	Int0vec+1,	/*  keyboard interrupts */
	 Uart1vec=	Int0vec+3,	/*  modem line */
	 Uart0vec=	Int0vec+4,	/*  serial line */
	 PCMCIAvec=	Int0vec+5,	/*  PCMCIA card change */
	 Floppyvec=	Int0vec+6,	/*  floppy interrupts */
	 Parallelvec=	Int0vec+7,	/*  parallel port interrupts */
	Int1vec=	Int0vec+8,
	 Ethervec=	Int0vec+10,	/*  ethernet interrupt */
	 Mousevec=	Int0vec+12,	/*  mouse interrupt */
	 Matherr2vec=	Int0vec+13,	/*  math coprocessor */
	 ATA0vec=	Int0vec+14,	/*  hard disk */

	Syscallvec=	64,
};

/*
 *  8259 interrupt controllers
 */
enum
{
	Int0ctl=	0x20,		/* control port (ICW1, OCW2, OCW3) */
	Int0aux=	0x21,		/* everything else (ICW2, ICW3, ICW4, OCW1) */
	Int1ctl=	0xA0,		/* control port */
	Int1aux=	0xA1,		/* everything else (ICW2, ICW3, ICW4, OCW1) */

	Icw1=		0x10,		/* select bit in ctl register */
	Ocw2=		0x00,
	Ocw3=		0x08,

	EOI=		0x20,		/* non-specific end of interrupt */

	Elcr1=		0x4D0,		/* Edge/Level Triggered Register */
	Elcr2=		0x4D1,
};

extern int	int0mask;		/* interrupts enabled for first 8259 */
extern int	int1mask;		/* interrupts enabled for second 8259 */

#define NVRAUTHADDR	0
#define LINESIZE	0

enum {
	MaxEISA		= 16,
	EISAconfig	= 0xC80,

	MaxScsi		= 4,
	NTarget		= 16,

	MaxEther	= 4,
};

#define DMAOK(x, l)	((ulong)(((ulong)(x))+(l)) < (ulong)(KZERO|16*1024*1024))

enum {
	BusCBUS		= 0,		/* Corollary CBUS */
	BusCBUSII,			/* Corollary CBUS II */
	BusEISA,			/* Extended ISA */
	BusFUTURE,			/* IEEE Futurebus */
	BusINTERN,			/* Internal bus */
	BusISA,				/* Industry Standard Architecture */
	BusMBI,				/* Multibus I */
	BusMBII,			/* Multibus II */
	BusMCA,				/* Micro Channel Architecture */
	BusMPI,				/* MPI */
	BusMPSA,			/* MPSA */
	BusNUBUS,			/* Apple Macintosh NuBus */
	BusPCI,				/* Peripheral Component Interconnect */
	BusPCMCIA,			/* PC Memory Card International Association */
	BusTC,				/* DEC TurboChannel */
	BusVL,				/* VESA Local bus */
	BusVME,				/* VMEbus */
	BusXPRESS,			/* Express System Bus */
};

#define MKBUS(t,b,d,f)	(((t)<<24)|(((b)&0xFF)<<16)|(((d)&0x1F)<<11)|(((f)&0x07)<<8))
#define BUSFNO(tbdf)	(((tbdf)>>8)&0x07)
#define BUSDNO(tbdf)	(((tbdf)>>11)&0x1F)
#define BUSBNO(tbdf)	(((tbdf)>>16)&0xFF)
#define BUSTYPE(tbdf)	((tbdf)>>24)
#define BUSBDF(tbdf)	((tbdf)&0x00FFFF00)
#define BUSUNKNOWN	(-1)

/*
 * PCI support code.
 */
enum {					/* type 0 and type 1 pre-defined header */
	PciVID		= 0x00,		/* vendor ID */
	PciDID		= 0x02,		/* device ID */
	PciPCR		= 0x04,		/* command */
	PciPSR		= 0x06,		/* status */
	PciRID		= 0x08,		/* revision ID */
	PciCCRp		= 0x09,		/* programming interface class code */
	PciCCRu		= 0x0A,		/* sub-class code */
	PciCCRb		= 0x0B,		/* base class code */
	PciCLS		= 0x0C,		/* cache line size */
	PciLTR		= 0x0D,		/* latency timer */
	PciHDT		= 0x0E,		/* header type */
	PciBST		= 0x0F,		/* BIST */

	PciBAR0		= 0x10,		/* base address */
	PciBAR1		= 0x14,

	PciINTL		= 0x3C,		/* interrupt line */
	PciINTP		= 0x3D,		/* interrupt pin */
};

enum {					/* type 0 pre-defined header */
	PciBAR2		= 0x18,
	PciBAR3		= 0x1C,
	PciBAR4		= 0x20,
	PciBAR5		= 0x24,
	PciCIS		= 0x28,		/* cardbus CIS pointer */
	PciSVID		= 0x2C,		/* subsystem vendor ID */
	PciSID		= 0x2E,		/* cardbus CIS pointer */
	PciEBAR0	= 0x30,		/* expansion ROM base address */
	PciMGNT		= 0x3E,		/* burst period length */
	PciMLT		= 0x3F,		/* maximum latency between bursts */
};

enum {					/* type 1 pre-defined header */
	PciPBN		= 0x18,		/* primary bus number */
	PciSBN		= 0x19,		/* secondary bus number */
	PciUBN		= 0x1A,		/* subordinate bus number */
	PciSLTR		= 0x1B,		/* secondary latency timer */
	PciIBR		= 0x1C,		/* I/O base */
	PciILR		= 0x1D,		/* I/O limit */
	PciSPSR		= 0x1E,		/* secondary status */
	PciMBR		= 0x20,		/* memory base */
	PciMLR		= 0x22,		/* memory limit */
	PciPMBR		= 0x24,		/* prefetchable memory base */
	PciPMLR		= 0x26,		/* prefetchable memory limit */
	PciPUBR		= 0x28,		/* prefetchable base upper 32 bits */
	PciPULR		= 0x2C,		/* prefetchable limit upper 32 bits */
	PciIUBR		= 0x30,		/* I/O base upper 16 bits */
	PciIULR		= 0x32,		/* I/O limit upper 16 bits */
	PciEBAR1	= 0x28,		/* expansion ROM base address */
	PciBCR		= 0x3E,		/* bridge control register */
};

typedef struct Pcidev Pcidev;
typedef struct Pcidev {
	int	tbdf;			/* type+bus+device+function */
	ushort	vid;			/* vendor ID */
	ushort	did;			/* device ID */

	struct {
		ulong	bar;		/* base address */
		int	size;
	} mem[6];

	uchar	rid;
	uchar	ccrp;
	uchar	ccrb;
	uchar	intl;			/* interrupt line */
	ushort	ccru;			/* is uchar in cpu kernel */
	ulong	pcr;

	Pcidev*	list;
	Pcidev*	bridge;			/* down a bus */
	Pcidev*	link;			/* next device on this bno */
} Pcidev;

extern int pcicfgr8(Pcidev*, int);
extern int pcicfgr16(Pcidev*, int);
extern int pcicfgr32(Pcidev*, int);
extern void pcicfgw8(Pcidev*, int, int);
extern void pcicfgw16(Pcidev*, int, int);
extern void pcicfgw32(Pcidev*, int, int);
extern void pciclrmwi(Pcidev*);
extern void pcihinv(Pcidev*, ulong);
extern Pcidev* pcimatch(Pcidev*, int, int);
extern Pcidev* pcimatchtbdf(int);
extern void pcireset(void);
extern void pcisetbme(Pcidev*);
extern void pciclrbme(Pcidev*);

/*
 *  a parsed plan9.ini line
 */
#define ISAOPTLEN	16
#define NISAOPT		8

typedef struct ISAConf {
	char	type[NAMELEN];
	ulong	port;
	ulong	irq;
	ulong	dma;
	ulong	mem;
	ulong	size;
	ulong	freq;

	int	nopt;
	char	opt[NISAOPT][ISAOPTLEN];
} ISAConf;

extern int isaconfig(char*, int, ISAConf*);

/*
 * SCSI support code.
 */
enum {
	STblank		=-6,		/* blank block */
	STnomem		=-5,		/* buffer allocation failed */
	STtimeout	=-4,		/* bus timeout */
	STownid		=-3,		/* playing with myself */
	STharderr	=-2,		/* controller error of some kind */
	STinit		=-1,		/* */
	STok		= 0,		/* good */
	STcheck		= 0x02,		/* check condition */
	STcondmet	= 0x04,		/* condition met/good */
	STbusy		= 0x08,		/* busy */
	STintok		= 0x10,		/* intermediate/good */
	STintcondmet	= 0x14,		/* intermediate/condition met/good */
	STresconf	= 0x18,		/* reservation conflict */
	STterminated	= 0x22,		/* command terminated */
	STqfull		= 0x28,		/* queue full */
};

typedef struct Target {
	int	ctlrno;
	int	targetno;
	uchar*	inquiry;
	uchar*	sense;

	QLock;
	char	id[NAMELEN];
	int	ok;

	char	fflag;
	Filter	work[3];
	Filter	rate[3];
} Target;

typedef int (*Scsiio)(Target*, int, uchar*, int, void*, int*);