osfmk/i386/seg.h

   1 /*
   2  * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 #ifndef _I386_SEG_H_
  57 #define _I386_SEG_H_
  58 #ifndef __ASSEMBLER__
  59 #include <stdint.h>
  60 #include <mach/vm_types.h>
  61 #include <mach/vm_param.h>
  62 #include <architecture/i386/sel.h>
  63
  64 /*
  65  * i386 segmentation.
  66  */
  67
  68 static inline uint16_t
  69 sel_to_selector(sel_t   sel)
  70 {
  71         union {
  72                 sel_t           sel;
  73                 uint16_t        selector;
  74         } tconv;
  75
  76         tconv.sel = sel;
  77
  78         return tconv.selector;
  79 }
  80
  81 static inline sel_t
  82 selector_to_sel(uint16_t selector)
  83 {
  84         union {
  85                 uint16_t        selector;
  86                 sel_t           sel;
  87         } tconv;
  88
  89         tconv.selector = selector;
  90
  91         return tconv.sel;
  92 }
  93
  94 #define LDTSZ_MAX       8192    /* maximal size of the kernel ldt in entries */
  95 #define LDTSZ_DFL       (128)
  96 #define LDTSZ           (LDTSZ_MAX)
  97 #define LDTSZ_MIN       SEL_TO_INDEX(USER_SETTABLE)
  98 /* kernel ldt entries */
  99
 100 #define GDTSZ           19
 101
 102 /*
 103  * Interrupt table is always 256 entries long.
 104  */
 105 #define IDTSZ           256
 106
 107 #include <sys/cdefs.h>
 108
 109 /*
 110  * Real segment descriptor.
 111  */
 112 struct real_descriptor {
 113         uint32_t        limit_low:16,   /* limit 0..15 */
 114             base_low:16,                /* base  0..15 */
 115             base_med:8,                 /* base  16..23 */
 116             access:8,                   /* access byte */
 117             limit_high:4,               /* limit 16..19 */
 118             granularity:4,              /* granularity */
 119             base_high:8;                /* base 24..31 */
 120 };
 121 struct real_descriptor64 {
 122         uint32_t        limit_low16:16, /* limit 0..15 */
 123             base_low16:16,              /* base  0..15 */
 124             base_med8:8,                /* base  16..23 */
 125             access8:8,                  /* access byte */
 126             limit_high4:4,              /* limit 16..19 */
 127             granularity4:4,             /* granularity */
 128             base_high8:8,               /* base 24..31 */
 129             base_top32:32,              /* base 32..63 */
 130             reserved32:32;              /* reserved/zero */
 131 };
 132 struct real_gate {
 133         uint32_t        offset_low:16,  /* offset 0..15 */
 134             selector:16,
 135             word_count:8,
 136             access:8,
 137             offset_high:16;             /* offset 16..31 */
 138 };
 139 struct real_gate64 {
 140         uint32_t        offset_low16:16,        /* offset 0..15 */
 141             selector16:16,
 142             IST:3,
 143             zeroes5:5,
 144             access8:8,
 145             offset_high16:16,                   /* offset 16..31 */
 146             offset_top32:32,                    /* offset 32..63 */
 147             reserved32:32;                      /* reserved/zero */
 148 };
 149
 150 #define MAKE_REAL_DESCRIPTOR(base, lim, gran, acc) {\
 151         .limit_low = lim & 0xffff, \
 152         .limit_high = (lim >> 16) & 0xf, \
 153         .base_low = base & 0xffff, \
 154         .base_med = (base >> 16) & 0xff, \
 155         .base_high = (base >> 24) & 0xff, \
 156         .access = acc, \
 157         .granularity = gran \
 158 }
 159
 160 /*
 161  * We build descriptors and gates in a 'fake' format to let the
 162  * fields be contiguous.  We shuffle them into the real format
 163  * at runtime.
 164  */
 165 struct fake_descriptor {
 166         uint32_t        offset:32;              /* offset */
 167         uint32_t        lim_or_seg:20;          /* limit */
 168                                                 /* or segment, for gate */
 169         uint32_t        size_or_wdct:4;         /* size/granularity */
 170                                                 /* word count, for gate */
 171         uint32_t        access:8;               /* access */
 172 };
 173 struct fake_descriptor64 {
 174         uint64_t        offset64;               /* offset [0..31,32..63] */
 175         uint32_t        lim_or_seg:20;          /* limit */
 176                                                 /* or segment, for gate */
 177         uint32_t        size_or_IST:4;          /* size/granularity */
 178                                                 /* IST for gates */
 179         uint32_t        access:8;               /* access */
 180         uint32_t        reserved:32;            /* reserved/zero */
 181 };
 182
 183 typedef struct __attribute__((packed)) {
 184         uint16_t        size;
 185         void            *ptr;
 186 } x86_64_desc_register_t;
 187
 188
 189
 190 /*
 191  * Boot-time data for master (or only) CPU
 192  */
 193 extern struct real_descriptor   master_gdt[GDTSZ];
 194 extern struct real_descriptor   master_ldt[];
 195 extern struct i386_tss          master_ktss;
 196 extern struct sysenter_stack    master_sstk;
 197
 198 extern struct fake_descriptor64 master_idt64[IDTSZ];
 199 extern struct x86_64_tss        master_ktss64;
 200
 201 __BEGIN_DECLS
 202
 203 extern char                     df_task_stack[];
 204 extern char                     df_task_stack_end[];
 205 extern struct i386_tss          master_dftss;
 206 extern void                     df_task_start(void);
 207
 208 extern char                     mc_task_stack[];
 209 extern char                     mc_task_stack_end[];
 210 extern struct i386_tss          master_mctss;
 211 extern void                     mc_task_start(void);
 212
 213 __END_DECLS
 214
 215 #endif  /*__ASSEMBLER__*/
 216
 217 #define SZ_64           0x2                     /* 64-bit segment */
 218 #define SZ_32           0x4                     /* 32-bit segment */
 219 #define SZ_G            0x8                     /* 4K limit field */
 220
 221 #define ACC_A           0x01                    /* accessed */
 222 #define ACC_TYPE        0x1e                    /* type field: */
 223
 224 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 225
 226 #define ACC_LDT         0x02                        /* LDT */
 227 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 228 #define ACC_TASK_GATE   0x05                        /* task gate */
 229 #define ACC_TSS         0x09                        /* task segment */
 230 #define ACC_CALL_GATE   0x0c                        /* call gate */
 231 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 232 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 233
 234 #define ACC_TSS_BUSY    0x02                        /* task busy */
 235
 236 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 237
 238 #define ACC_DATA        0x10                        /* data */
 239 #define ACC_DATA_W      0x12                        /* data, writable */
 240 #define ACC_DATA_E      0x14                        /* data, expand-down */
 241 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 242                                                      *        writable */
 243 #define ACC_CODE        0x18                        /* code */
 244 #define ACC_CODE_R      0x1a                        /* code, readable */
 245 #define ACC_CODE_C      0x1c                        /* code, conforming */
 246 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 247                                                      *  readable */
 248 #define ACC_PL          0x60                    /* access rights: */
 249 #define ACC_PL_K        0x00                    /* kernel access only */
 250 #define ACC_PL_U        0x60                    /* user access */
 251 #define ACC_P           0x80                    /* segment present */
 252
 253 /*
 254  * Components of a selector
 255  */
 256 #define SEL_LDTS        0x04                    /* local selector */
 257 #define SEL_PL          0x03                    /* privilege level: */
 258 #define SEL_PL_K        0x00                        /* kernel selector */
 259 #define SEL_PL_U        0x03                        /* user selector */
 260
 261 /*
 262  * Convert selector to descriptor table index.
 263  */
 264 #define sel_idx(sel)    (selector_to_sel(sel).index)
 265 #define SEL_TO_INDEX(s) ((s)>>3)
 266
 267 #define NULL_SEG        0
 268
 269
 270 /*
 271  * Kernel descriptors for MACH - 64-bit flat address space.
 272  */
 273 #define KERNEL64_CS     0x08            /* 1:  K64 code */
 274 #define SYSENTER_CS     0x0b            /*     U32 sysenter pseudo-segment */
 275 #define KERNEL64_SS     0x10            /* 2:  KERNEL64_CS+8 for syscall */
 276 #define USER_CS         0x1b            /* 3:  U32 code */
 277 #define USER_DS         0x23            /* 4:  USER_CS+8 for sysret */
 278 #define USER64_CS       0x2b            /* 5:  USER_CS+16 for sysret */
 279 #define USER64_DS       USER_DS         /*     U64 data pseudo-segment */
 280 #define KERNEL_LDT      0x30            /* 6:  */
 281                                         /* 7:  other 8 bytes of KERNEL_LDT */
 282 #define KERNEL_TSS      0x40            /* 8:  */
 283                                         /* 9:  other 8 bytes of KERNEL_TSS */
 284 #define KERNEL32_CS     0x50            /* 10: */
 285 #define USER_LDT        0x58            /* 11: */
 286                                         /* 12: other 8 bytes of USER_LDT */
 287 #define KERNEL_DS       0x68            /* 13: 32-bit kernel data */
 288
 289
 290 #define SYSENTER_TF_CS  (USER_CS|0x10000)
 291 #define SYSENTER_DS     KERNEL64_SS     /* sysenter kernel data segment */
 292
 293 #endif  /* _I386_SEG_H_ */
 294 #ifdef __x86_64__
 295 /*
 296  * 64-bit kernel LDT descriptors
 297  */
 298 #define SYSCALL_CS      0x07            /* syscall pseudo-segment */
 299 #define USER_CTHREAD    0x0f            /* user cthread area */
 300 #define USER_SETTABLE   0x1f            /* start of user settable ldt entries */
 301 #endif