osfmk/i386/thread.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, 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) 1991,1990,1989 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 /*
  57  */
  58
  59 /*
  60  *      File:   machine/thread.h
  61  *
  62  *      This file contains the structure definitions for the thread
  63  *      state as applied to I386 processors.
  64  */
  65
  66 #ifndef _I386_THREAD_H_
  67 #define _I386_THREAD_H_
  68
  69 #include <mach/boolean.h>
  70 #include <mach/i386/vm_types.h>
  71 #include <mach/i386/fp_reg.h>
  72 #include <mach/thread_status.h>
  73
  74 #include <kern/lock.h>
  75
  76 #include <i386/iopb.h>
  77 #include <i386/seg.h>
  78 #include <i386/tss.h>
  79 #include <i386/eflags.h>
  80
  81 /*
  82  *      i386_saved_state:
  83  *
  84  *      Has been exported to servers.  See: mach/i386/thread_status.h
  85  *
  86  *      This structure corresponds to the state of user registers
  87  *      as saved upon kernel entry.  It lives in the pcb.
  88  *      It is also pushed onto the stack for exceptions in the kernel.
  89  *      For performance, it is also used directly in syscall exceptions
  90  *      if the server has requested i386_THREAD_STATE flavor for the exception
  91  *      port.
  92  *
  93  *      We define the following as an alias for the "esp" field of the
  94  *      structure, because we actually save cr2 here, not the kernel esp.
  95  */
  96 #define cr2     esp
  97
  98 /*
  99  *      Save area for user floating-point state.
 100  *      Allocated only when necessary.
 101  */
 102
 103 struct i386_fpsave_state {
 104         boolean_t               fp_valid;
 105         struct i386_fp_save     fp_save_state;
 106         struct i386_fp_regs     fp_regs;
 107         struct i386_fx_save     fx_save_state __attribute__ ((aligned (16)));
 108         int                     fp_save_flavor;
 109 };
 110
 111 /*
 112  *      v86_assist_state:
 113  *
 114  *      This structure provides data to simulate 8086 mode
 115  *      interrupts.  It lives in the pcb.
 116  */
 117
 118 struct v86_assist_state {
 119         vm_offset_t             int_table;
 120         unsigned short          int_count;
 121         unsigned short          flags;  /* 8086 flag bits */
 122 };
 123 #define V86_IF_PENDING          0x8000  /* unused bit */
 124
 125 /*
 126  *      i386_interrupt_state:
 127  *
 128  *      This structure describes the set of registers that must
 129  *      be pushed on the current ring-0 stack by an interrupt before
 130  *      we can switch to the interrupt stack.
 131  */
 132
 133 struct i386_interrupt_state {
 134         int     gs;
 135         int     fs;
 136         int     es;
 137         int     ds;
 138         int     edx;
 139         int     ecx;
 140         int     eax;
 141         int     eip;
 142         int     cs;
 143         int     efl;
 144 };
 145
 146 /*
 147  *      i386_kernel_state:
 148  *
 149  *      This structure corresponds to the state of kernel registers
 150  *      as saved in a context-switch.  It lives at the base of the stack.
 151  */
 152
 153 struct i386_kernel_state {
 154         int                     k_ebx;  /* kernel context */
 155         int                     k_esp;
 156         int                     k_ebp;
 157         int                     k_edi;
 158         int                     k_esi;
 159         int                     k_eip;
 160 };
 161
 162 /*
 163  *      i386_machine_state:
 164  *
 165  *      This structure corresponds to special machine state.
 166  *      It lives in the pcb.  It is not saved by default.
 167  */
 168
 169 struct i386_machine_state {
 170         iopb_tss_t              io_tss;
 171         struct user_ldt *       ldt;
 172         struct i386_fpsave_state *ifps;
 173         struct v86_assist_state v86s;
 174 };
 175
 176 typedef struct pcb {
 177         struct i386_interrupt_state iis[2];     /* interrupt and NMI */
 178         struct i386_saved_state iss;
 179         struct i386_machine_state ims;
 180 #ifdef  MACH_BSD
 181         unsigned long   cthread_self;           /* for use of cthread package */
 182         struct real_descriptor cthread_desc;
 183         unsigned long  uldt_selector;          /* user ldt selector to set */
 184         struct real_descriptor uldt_desc;      /* the actual user setable ldt data */
 185 #endif
 186         decl_simple_lock_data(,lock)
 187 } *pcb_t;
 188
 189 /*
 190  * Maps state flavor to number of words in the state:
 191  */
 192 __private_extern__ unsigned int _MachineStateCount[];
 193
 194 #define USER_REGS(ThrAct)       (&(ThrAct)->machine.pcb->iss)
 195
 196 #define act_machine_state_ptr(ThrAct)   (thread_state_t)USER_REGS(ThrAct)
 197
 198
 199 #define is_user_thread(ThrAct)  \
 200         ((USER_REGS(ThrAct)->efl & EFL_VM) \
 201          || ((USER_REGS(ThrAct)->cs & 0x03) != 0))
 202
 203 #define user_pc(ThrAct)         (USER_REGS(ThrAct)->eip)
 204 #define user_sp(ThrAct)         (USER_REGS(ThrAct)->uesp)
 205
 206 struct machine_thread {
 207         /*
 208          * pointer to process control block
 209          *      (actual storage may as well be here, too)
 210          */
 211         struct pcb xxx_pcb;
 212         pcb_t pcb;
 213
 214 };
 215
 216 extern struct i386_saved_state *get_user_regs(thread_t);
 217
 218 extern void *act_thread_csave(void);
 219 extern void act_thread_catt(void *ctx);
 220 extern void act_thread_cfree(void *ctx);
 221
 222 /*
 223  *      i386_exception_link:
 224  *
 225  *      This structure lives at the high end of the kernel stack.
 226  *      It points to the current thread`s user registers.
 227  */
 228 struct i386_exception_link {
 229         struct i386_saved_state *saved_state;
 230 };
 231
 232
 233 /*
 234  *      On the kernel stack is:
 235  *      stack:  ...
 236  *              struct i386_exception_link
 237  *              struct i386_kernel_state
 238  *      stack+KERNEL_STACK_SIZE
 239  */
 240
 241 #define STACK_IKS(stack)        \
 242         ((struct i386_kernel_state *)((stack) + KERNEL_STACK_SIZE) - 1)
 243 #define STACK_IEL(stack)        \
 244         ((struct i386_exception_link *)STACK_IKS(stack) - 1)
 245
 246 /*
 247  * Return address of the function that called current function, given
 248  *      address of the first parameter of current function.
 249  */
 250 #define GET_RETURN_PC(addr)     (*((vm_offset_t *)addr - 1))
 251
 252 /*
 253  * Defining this indicates that MD code will supply an exception()
 254  * routine, conformant with kern/exception.c (dependency alert!)
 255  * but which does wonderfully fast, machine-dependent magic.
 256  */
 257 #define MACHINE_FAST_EXCEPTION 1
 258
 259 #endif  /* _I386_THREAD_H_ */