[unix-history] / usr / src / sys / i386 / include / segments.h

/*-
 * Copyright (c) 1989, 1990 William F. Jolitz
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)segments.h	8.1 (Berkeley) %G%
 */

/*
 * 386 Segmentation Data Structures and definitions
 *	William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
 */

/*
 * Selectors
 */

#define	ISPL(s)	((s)&3)		/* what is the priority level of a selector */
#define	SEL_KPL	0		/* kernel priority level */	
#define	SEL_UPL	3		/* user priority level */	
#define	ISLDT(s)	((s)&SEL_LDT)	/* is it local or global */
#define	SEL_LDT	4		/* local descriptor table */	
#define	IDXSEL(s)	(((s)>>3) & 0x1fff)		/* index of selector */
#define	LSEL(s,r)	(((s)<<3) | SEL_LDT | r)	/* a local selector */
#define	GSEL(s,r)	(((s)<<3) | r)			/* a global selector */

/*
 * Memory and System segment descriptors
 */
struct	segment_descriptor	{
	unsigned sd_lolimit:16 ;	/* segment extent (lsb) */
	unsigned sd_lobase:24 ;		/* segment base address (lsb) */
	unsigned sd_type:5 ;		/* segment type */
	unsigned sd_dpl:2 ;		/* segment descriptor priority level */
	unsigned sd_p:1 ;		/* segment descriptor present */
	unsigned sd_hilimit:4 ;		/* segment extent (msb) */
	unsigned sd_xx:2 ;		/* unused */
	unsigned sd_def32:1 ;		/* default 32 vs 16 bit size */
	unsigned sd_gran:1 ;		/* limit granularity (byte/page units)*/
	unsigned sd_hibase:8 ;		/* segment base address  (msb) */
} ;

/*
 * Gate descriptors (e.g. indirect descriptors)
 */
struct	gate_descriptor	{
	unsigned gd_looffset:16 ;	/* gate offset (lsb) */
	unsigned gd_selector:16 ;	/* gate segment selector */
	unsigned gd_stkcpy:5 ;		/* number of stack wds to cpy */
	unsigned gd_xx:3 ;		/* unused */
	unsigned gd_type:5 ;		/* segment type */
	unsigned gd_dpl:2 ;		/* segment descriptor priority level */
	unsigned gd_p:1 ;		/* segment descriptor present */
	unsigned gd_hioffset:16 ;	/* gate offset (msb) */
} ;

/*
 * Generic descriptor
 */
union	descriptor	{
	struct	segment_descriptor sd;
	struct	gate_descriptor gd;
};
#define	d_type	gd.gd_type

	/* system segments and gate types */
#define	SDT_SYSNULL	 0	/* system null */
#define	SDT_SYS286TSS	 1	/* system 286 TSS available */
#define	SDT_SYSLDT	 2	/* system local descriptor table */
#define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
#define	SDT_SYS286CGT	 4	/* system 286 call gate */
#define	SDT_SYSTASKGT	 5	/* system task gate */
#define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
#define	SDT_SYS286TGT	 7	/* system 286 trap gate */
#define	SDT_SYSNULL2	 8	/* system null again */
#define	SDT_SYS386TSS	 9	/* system 386 TSS available */
#define	SDT_SYSNULL3	10	/* system null again */
#define	SDT_SYS386BSY	11	/* system 386 TSS busy */
#define	SDT_SYS386CGT	12	/* system 386 call gate */
#define	SDT_SYSNULL4	13	/* system null again */
#define	SDT_SYS386IGT	14	/* system 386 interrupt gate */
#define	SDT_SYS386TGT	15	/* system 386 trap gate */

	/* memory segment types */
#define	SDT_MEMRO	16	/* memory read only */
#define	SDT_MEMROA	17	/* memory read only accessed */
#define	SDT_MEMRW	18	/* memory read write */
#define	SDT_MEMRWA	19	/* memory read write accessed */
#define	SDT_MEMROD	20	/* memory read only expand dwn limit */
#define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
#define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
#define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
#define	SDT_MEME	24	/* memory execute only */
#define	SDT_MEMEA	25	/* memory execute only accessed */
#define	SDT_MEMER	26	/* memory execute read */
#define	SDT_MEMERA	27	/* memory execute read accessed */
#define	SDT_MEMEC	28	/* memory execute only conforming */
#define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
#define	SDT_MEMERC	30	/* memory execute read conforming */
#define	SDT_MEMERAC	31	/* memory execute read accessed conforming */

/* is memory segment descriptor pointer ? */
#define ISMEMSDP(s)	((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC)

/* is 286 gate descriptor pointer ? */
#define IS286GDP(s)	(((s->d_type) >= SDT_SYS286CGT \
				 && (s->d_type) < SDT_SYS286TGT))

/* is 386 gate descriptor pointer ? */
#define IS386GDP(s)	(((s->d_type) >= SDT_SYS386CGT \
				&& (s->d_type) < SDT_SYS386TGT))

/* is gate descriptor pointer ? */
#define ISGDP(s)	(IS286GDP(s) || IS386GDP(s))

/* is segment descriptor pointer ? */
#define ISSDP(s)	(ISMEMSDP(s) || !ISGDP(s))

/* is system segment descriptor pointer ? */
#define ISSYSSDP(s)	(!ISMEMSDP(s) && !ISGDP(s))

/*
 * Software definitions are in this convenient format,
 * which are translated into inconvenient segment descriptors
 * when needed to be used by the 386 hardware
 */

struct	soft_segment_descriptor	{
	unsigned ssd_base ;		/* segment base address  */
	unsigned ssd_limit ;		/* segment extent */
	unsigned ssd_type:5 ;		/* segment type */
	unsigned ssd_dpl:2 ;		/* segment descriptor priority level */
	unsigned ssd_p:1 ;		/* segment descriptor present */
	unsigned ssd_xx:4 ;		/* unused */
	unsigned ssd_xx1:2 ;		/* unused */
	unsigned ssd_def32:1 ;		/* default 32 vs 16 bit size */
	unsigned ssd_gran:1 ;		/* limit granularity (byte/page units)*/
};

extern ssdtosd() ;	/* to decode a ssd */
extern sdtossd() ;	/* to encode a sd */

/*
 * region descriptors, used to load gdt/idt tables before segments yet exist
 */
struct region_descriptor {
	unsigned rd_limit:16 ;		/* segment extent */
	char *rd_base;			/* base address  */
};

/*
 * Segment Protection Exception code bits
 */

#define	SEGEX_EXT	0x01	/* recursive or externally induced */
#define	SEGEX_IDT	0x02	/* interrupt descriptor table */
#define	SEGEX_TI	0x04	/* local descriptor table */
				/* other bits are affected descriptor index */
#define SEGEX_IDX(s)	((s)>>3)&0x1fff)
Commit	Line	Data
fdc6cea8	1	/*-
a4fbad88	2	* Copyright (c) 1989, 1990 William F. Jolitz
789f2822 KB	3	* Copyright (c) 1990, 1993
789f2822 KB	4	* The Regents of the University of California. All rights reserved.
fdc6cea8 BJ	5	*
fdc6cea8 BJ	6	* This code is derived from software contributed to Berkeley by
141d1978	7	* William Jolitz.
fdc6cea8	8	*
a4fbad88	9	* %sccs.include.redist.c%
fdc6cea8	10	*
789f2822	11	* @(#)segments.h 8.1 (Berkeley) %G%
fdc6cea8 BJ	12	*/
fdc6cea8 BJ	13
cb0817da BJ	14	/*
	15	* 386 Segmentation Data Structures and definitions
	16	* William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
	17	*/
	18
	19	/*
	20	* Selectors
	21	*/
	22
	23	#define ISPL(s) ((s)&3) /* what is the priority level of a selector */
	24	#define SEL_KPL 0 /* kernel priority level */
	25	#define SEL_UPL 3 /* user priority level */
	26	#define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
	27	#define SEL_LDT 4 /* local descriptor table */
	28	#define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
	29	#define LSEL(s,r) (((s)<<3) \| SEL_LDT \| r) /* a local selector */
	30	#define GSEL(s,r) (((s)<<3) \| r) /* a global selector */
	31
	32	/*
	33	* Memory and System segment descriptors
	34	*/
	35	struct segment_descriptor {
	36	unsigned sd_lolimit:16 ; /* segment extent (lsb) */
	37	unsigned sd_lobase:24 ; /* segment base address (lsb) */
	38	unsigned sd_type:5 ; /* segment type */
	39	unsigned sd_dpl:2 ; /* segment descriptor priority level */
	40	unsigned sd_p:1 ; /* segment descriptor present */
	41	unsigned sd_hilimit:4 ; /* segment extent (msb) */
	42	unsigned sd_xx:2 ; /* unused */
	43	unsigned sd_def32:1 ; /* default 32 vs 16 bit size */
	44	unsigned sd_gran:1 ; /* limit granularity (byte/page units)*/
	45	unsigned sd_hibase:8 ; /* segment base address (msb) */
	46	} ;
	47
	48	/*
	49	* Gate descriptors (e.g. indirect descriptors)
	50	*/
	51	struct gate_descriptor {
	52	unsigned gd_looffset:16 ; /* gate offset (lsb) */
	53	unsigned gd_selector:16 ; /* gate segment selector */
	54	unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */
	55	unsigned gd_xx:3 ; /* unused */
	56	unsigned gd_type:5 ; /* segment type */
	57	unsigned gd_dpl:2 ; /* segment descriptor priority level */
	58	unsigned gd_p:1 ; /* segment descriptor present */
	59	unsigned gd_hioffset:16 ; /* gate offset (msb) */
	60	} ;
	61
	62	/*
	63	* Generic descriptor
	64	*/
	65	union descriptor {
	66	struct segment_descriptor sd;
	67	struct gate_descriptor gd;
	68	};
	69	#define d_type gd.gd_type
	70
	71	/* system segments and gate types */
	72	#define SDT_SYSNULL 0 /* system null */
	73	#define SDT_SYS286TSS 1 /* system 286 TSS available */
	74	#define SDT_SYSLDT 2 /* system local descriptor table */
	75	#define SDT_SYS286BSY 3 /* system 286 TSS busy */
	76	#define SDT_SYS286CGT 4 /* system 286 call gate */
	77	#define SDT_SYSTASKGT 5 /* system task gate */
78	#define SDT_SYS286IGT 6 /* system 286 interrupt gate */
79	#define SDT_SYS286TGT 7 /* system 286 trap gate */
80	#define SDT_SYSNULL2 8 /* system null again */
81	#define SDT_SYS386TSS 9 /* system 386 TSS available */
82	#define SDT_SYSNULL3 10 /* system null again */
83	#define SDT_SYS386BSY 11 /* system 386 TSS busy */
84	#define SDT_SYS386CGT 12 /* system 386 call gate */
85	#define SDT_SYSNULL4 13 /* system null again */
86	#define SDT_SYS386IGT 14 /* system 386 interrupt gate */
87	#define SDT_SYS386TGT 15 /* system 386 trap gate */
88
89	/* memory segment types */
90	#define SDT_MEMRO 16 /* memory read only */
91	#define SDT_MEMROA 17 /* memory read only accessed */
92	#define SDT_MEMRW 18 /* memory read write */
93	#define SDT_MEMRWA 19 /* memory read write accessed */
94	#define SDT_MEMROD 20 /* memory read only expand dwn limit */
95	#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
96	#define SDT_MEMRWD 22 /* memory read write expand dwn limit */
97	#define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */
98	#define SDT_MEME 24 /* memory execute only */
99	#define SDT_MEMEA 25 /* memory execute only accessed */
100	#define SDT_MEMER 26 /* memory execute read */
101	#define SDT_MEMERA 27 /* memory execute read accessed */
102	#define SDT_MEMEC 28 /* memory execute only conforming */
103	#define SDT_MEMEAC 29 /* memory execute only accessed conforming */
104	#define SDT_MEMERC 30 /* memory execute read conforming */
105	#define SDT_MEMERAC 31 /* memory execute read accessed conforming */
106
107	/* is memory segment descriptor pointer ? */
108	#define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC)
109
110	/* is 286 gate descriptor pointer ? */
111	#define IS286GDP(s) (((s->d_type) >= SDT_SYS286CGT \
112	&& (s->d_type) < SDT_SYS286TGT))
113
114	/* is 386 gate descriptor pointer ? */
115	#define IS386GDP(s) (((s->d_type) >= SDT_SYS386CGT \
116	&& (s->d_type) < SDT_SYS386TGT))
117
118	/* is gate descriptor pointer ? */
119	#define ISGDP(s) (IS286GDP(s) \|\| IS386GDP(s))
120
121	/* is segment descriptor pointer ? */
122	#define ISSDP(s) (ISMEMSDP(s) \|\| !ISGDP(s))
123
124	/* is system segment descriptor pointer ? */
125	#define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s))
126
127	/*
128	* Software definitions are in this convenient format,
129	* which are translated into inconvenient segment descriptors
130	* when needed to be used by the 386 hardware
131	*/
132
133	struct soft_segment_descriptor {
134	unsigned ssd_base ; /* segment base address */
135	unsigned ssd_limit ; /* segment extent */
136	unsigned ssd_type:5 ; /* segment type */
137	unsigned ssd_dpl:2 ; /* segment descriptor priority level */
138	unsigned ssd_p:1 ; /* segment descriptor present */
139	unsigned ssd_xx:4 ; /* unused */
140	unsigned ssd_xx1:2 ; /* unused */
141	unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */
142	unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/
143	};
144
145	extern ssdtosd() ; /* to decode a ssd */
146	extern sdtossd() ; /* to encode a sd */
147
148	/*
149	* region descriptors, used to load gdt/idt tables before segments yet exist
150	*/
151	struct region_descriptor {
152	unsigned rd_limit:16 ; /* segment extent */
153	char rd_base; / base address */
154	};
155
fdc6cea8 BJ	156	/*
	157	* Segment Protection Exception code bits
	158	*/
	159
	160	#define SEGEX_EXT 0x01 /* recursive or externally induced */
	161	#define SEGEX_IDT 0x02 /* interrupt descriptor table */
	162	#define SEGEX_TI 0x04 /* local descriptor table */
	163	/* other bits are affected descriptor index */
	164	#define SEGEX_IDX(s) ((s)>>3)&0x1fff)