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/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* Copyright (c) 1991 IBM Corporation
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation,
* and that the name IBM not be used in advertising or publicity
* pertaining to distribution of the software without specific, written
* prior permission.
*
* CARNEGIE MELLON AND IBM ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON AND IBM DISCLAIM ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#ifndef _I386_SEG_H_
#define _I386_SEG_H_
#include <mach/inline.h>
/*
* i386 segmentation.
*/
/* Note: the value of KERNEL_RING is handled by hand in locore.S */
#ifdef MACH_RING1
#define KERNEL_RING 1
#else /* MACH_RING1 */
#define KERNEL_RING 0
#endif /* MACH_RING1 */
#ifndef __ASSEMBLER__
/*
* Real segment descriptor.
*/
struct real_descriptor {
unsigned int limit_low:16, /* limit 0..15 */
base_low:16, /* base 0..15 */
base_med:8, /* base 16..23 */
access:8, /* access byte */
limit_high:4, /* limit 16..19 */
granularity:4, /* granularity */
base_high:8; /* base 24..31 */
};
struct real_gate {
unsigned int offset_low:16, /* offset 0..15 */
selector:16,
word_count:8,
access:8,
offset_high:16; /* offset 16..31 */
};
#endif /* !__ASSEMBLER__ */
#define SZ_64 0x2 /* 64-bit segment */
#define SZ_32 0x4 /* 32-bit segment */
#define SZ_16 0x0 /* 16-bit segment */
#define SZ_G 0x8 /* 4K limit field */
#define ACC_A 0x01 /* accessed */
#define ACC_TYPE 0x1e /* type field: */
#define ACC_TYPE_SYSTEM 0x00 /* system descriptors: */
#define ACC_LDT 0x02 /* LDT */
#define ACC_CALL_GATE_16 0x04 /* 16-bit call gate */
#define ACC_TASK_GATE 0x05 /* task gate */
#define ACC_TSS 0x09 /* task segment */
#define ACC_CALL_GATE 0x0c /* call gate */
#define ACC_INTR_GATE 0x0e /* interrupt gate */
#define ACC_TRAP_GATE 0x0f /* trap gate */
#define ACC_TSS_BUSY 0x02 /* task busy */
#define ACC_TYPE_USER 0x10 /* user descriptors */
#define ACC_DATA 0x10 /* data */
#define ACC_DATA_W 0x12 /* data, writable */
#define ACC_DATA_E 0x14 /* data, expand-down */
#define ACC_DATA_EW 0x16 /* data, expand-down,
writable */
#define ACC_CODE 0x18 /* code */
#define ACC_CODE_R 0x1a /* code, readable */
#define ACC_CODE_C 0x1c /* code, conforming */
#define ACC_CODE_CR 0x1e /* code, conforming,
readable */
#define ACC_PL 0x60 /* access rights: */
#define ACC_PL_K (KERNEL_RING << 5) /* kernel access only */
#define ACC_PL_U 0x60 /* user access */
#define ACC_P 0x80 /* segment present */
/*
* Components of a selector
*/
#define SEL_LDT 0x04 /* local selector */
#define SEL_PL 0x03 /* privilege level: */
#define SEL_PL_K KERNEL_RING /* kernel selector */
#define SEL_PL_U 0x03 /* user selector */
/*
* Convert selector to descriptor table index.
*/
#define sel_idx(sel) ((sel)>>3)
#ifndef __ASSEMBLER__
#include <mach/inline.h>
#include <mach/xen.h>
/* Format of a "pseudo-descriptor", used for loading the IDT and GDT. */
struct pseudo_descriptor
{
unsigned short limit;
unsigned long linear_base;
short pad;
} __attribute__((packed));
/* Load the processor's IDT, GDT, or LDT pointers. */
MACH_INLINE void lgdt(struct pseudo_descriptor *pdesc)
{
__asm volatile("lgdt %0" : : "m" (*pdesc));
}
MACH_INLINE void lidt(struct pseudo_descriptor *pdesc)
{
__asm volatile("lidt %0" : : "m" (*pdesc));
}
MACH_INLINE void lldt(unsigned short ldt_selector)
{
__asm volatile("lldt %w0" : : "r" (ldt_selector) : "memory");
}
#ifdef CODE16
#define i16_lgdt lgdt
#define i16_lidt lidt
#define i16_lldt lldt
#endif
/* Fill a segment descriptor. */
MACH_INLINE void
fill_descriptor(struct real_descriptor *_desc, unsigned base, unsigned limit,
unsigned char access, unsigned char sizebits)
{
/* TODO: when !MACH_PV_DESCRIPTORS, setting desc and just memcpy isn't simpler actually */
#ifdef MACH_PV_DESCRIPTORS
struct real_descriptor __desc, *desc = &__desc;
#else /* MACH_PV_DESCRIPTORS */
struct real_descriptor *desc = _desc;
#endif /* MACH_PV_DESCRIPTORS */
if (limit > 0xfffff)
{
limit >>= 12;
sizebits |= SZ_G;
}
desc->limit_low = limit & 0xffff;
desc->base_low = base & 0xffff;
desc->base_med = (base >> 16) & 0xff;
desc->access = access | ACC_P;
desc->limit_high = limit >> 16;
desc->granularity = sizebits;
desc->base_high = base >> 24;
#ifdef MACH_PV_DESCRIPTORS
if (hyp_do_update_descriptor(kv_to_ma(_desc), *(uint64_t*)desc))
panic("couldn't update descriptor(%lu to %08lx%08lx)\n", (vm_offset_t) kv_to_ma(_desc), *(((unsigned long*)desc)+1), *(unsigned long *)desc);
#endif /* MACH_PV_DESCRIPTORS */
}
/* Fill a gate with particular values. */
MACH_INLINE void
fill_gate(struct real_gate *gate, unsigned offset, unsigned short selector,
unsigned char access, unsigned char word_count)
{
gate->offset_low = offset & 0xffff;
gate->selector = selector;
gate->word_count = word_count;
gate->access = access | ACC_P;
gate->offset_high = (offset >> 16) & 0xffff;
}
#endif /* !__ASSEMBLER__ */
#endif /* _I386_SEG_H_ */
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