mm_context.h

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/*
 * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
 * Licensed under the GPL
 *
 * Author: Bodo Stroesser <[email protected]>
 */

#ifndef __ASM_LDT_H
#define __ASM_LDT_H

#include <linux/mutex.h>
#include <asm/ldt.h>

extern void ldt_host_info(void);

#define LDT_PAGES_MAX \
    ((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
#define LDT_ENTRIES_PER_PAGE \
    (PAGE_SIZE/LDT_ENTRY_SIZE)
#define LDT_DIRECT_ENTRIES \
    ((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)

struct ldt_entry {
    __u32 a;
    __u32 b;
};

typedef struct uml_ldt {
    int entry_count;
    struct mutex lock;
    union {
        struct ldt_entry * pages[LDT_PAGES_MAX];
        struct ldt_entry entries[LDT_DIRECT_ENTRIES];
    } u;
} uml_ldt_t;

#define LDT_entry_a(info) \
    ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))

#define LDT_entry_b(info) \
    (((info)->base_addr & 0xff000000) | \
    (((info)->base_addr & 0x00ff0000) >> 16) | \
    ((info)->limit & 0xf0000) | \
    (((info)->read_exec_only ^ 1) << 9) | \
    ((info)->contents << 10) | \
    (((info)->seg_not_present ^ 1) << 15) | \
    ((info)->seg_32bit << 22) | \
    ((info)->limit_in_pages << 23) | \
    ((info)->useable << 20) | \
    0x7000)

#define _LDT_empty(info) (\
    (info)->base_addr   == 0    && \
    (info)->limit       == 0    && \
    (info)->contents    == 0    && \
    (info)->read_exec_only  == 1    && \
    (info)->seg_32bit   == 0    && \
    (info)->limit_in_pages  == 0    && \
    (info)->seg_not_present == 1    && \
    (info)->useable     == 0    )

#ifdef CONFIG_X86_64
#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
#else
#define LDT_empty(info) (_LDT_empty(info))
#endif

struct uml_arch_mm_context {
    uml_ldt_t ldt;
};

#endif