arch/x86/um/asm/mm_context.h

   1 /*
   2  * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
   3  * Licensed under the GPL
   4  *
   5  * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
   6  */
   7
   8 #ifndef __ASM_LDT_H
   9 #define __ASM_LDT_H
  10
  11 #include <linux/mutex.h>
  12 #include <asm/ldt.h>
  13
  14 extern void ldt_host_info(void);
  15
  16 #define LDT_PAGES_MAX \
  17         ((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
  18 #define LDT_ENTRIES_PER_PAGE \
  19         (PAGE_SIZE/LDT_ENTRY_SIZE)
  20 #define LDT_DIRECT_ENTRIES \
  21         ((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
  22
  23 struct ldt_entry {
  24         __u32 a;
  25         __u32 b;
  26 };
  27
  28 typedef struct uml_ldt {
  29         int entry_count;
  30         struct mutex lock;
  31         union {
  32                 struct ldt_entry * pages[LDT_PAGES_MAX];
  33                 struct ldt_entry entries[LDT_DIRECT_ENTRIES];
  34         } u;
  35 } uml_ldt_t;
  36
  37 #define LDT_entry_a(info) \
  38         ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
  39
  40 #define LDT_entry_b(info) \
  41         (((info)->base_addr & 0xff000000) | \
  42         (((info)->base_addr & 0x00ff0000) >> 16) | \
  43         ((info)->limit & 0xf0000) | \
  44         (((info)->read_exec_only ^ 1) << 9) | \
  45         ((info)->contents << 10) | \
  46         (((info)->seg_not_present ^ 1) << 15) | \
  47         ((info)->seg_32bit << 22) | \
  48         ((info)->limit_in_pages << 23) | \
  49         ((info)->useable << 20) | \
  50         0x7000)
  51
  52 #define _LDT_empty(info) (\
  53         (info)->base_addr       == 0    && \
  54         (info)->limit           == 0    && \
  55         (info)->contents        == 0    && \
  56         (info)->read_exec_only  == 1    && \
  57         (info)->seg_32bit       == 0    && \
  58         (info)->limit_in_pages  == 0    && \
  59         (info)->seg_not_present == 1    && \
  60         (info)->useable         == 0    )
  61
  62 #ifdef CONFIG_X86_64
  63 #define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
  64 #else
  65 #define LDT_empty(info) (_LDT_empty(info))
  66 #endif
  67
  68 struct uml_arch_mm_context {
  69         uml_ldt_t ldt;
  70 };
  71
  72 #endif