osfmk/i386/thread.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 /*
  54  *      File:   machine/thread.h
  55  *
  56  *      This file contains the structure definitions for the thread
  57  *      state as applied to I386 processors.
  58  */
  59
  60 #ifndef _I386_THREAD_H_
  61 #define _I386_THREAD_H_
  62
  63 #include <mach/boolean.h>
  64 #include <mach/i386/vm_types.h>
  65 #include <mach/i386/fp_reg.h>
  66 #include <mach/thread_status.h>
  67
  68 #include <kern/lock.h>
  69
  70 #include <i386/iopb.h>
  71 #include <i386/seg.h>
  72 #include <i386/tss.h>
  73 #include <i386/eflags.h>
  74
  75 /*
  76  *      i386_saved_state:
  77  *
  78  *      Has been exported to servers.  See: mach/i386/thread_status.h
  79  *
  80  *      This structure corresponds to the state of user registers
  81  *      as saved upon kernel entry.  It lives in the pcb.
  82  *      It is also pushed onto the stack for exceptions in the kernel.
  83  *      For performance, it is also used directly in syscall exceptions
  84  *      if the server has requested i386_THREAD_STATE flavor for the exception
  85  *      port.
  86  *
  87  *      We define the following as an alias for the "esp" field of the
  88  *      structure, because we actually save cr2 here, not the kernel esp.
  89  */
  90 #define cr2     esp
  91
  92 /*
  93  *      Save area for user floating-point state.
  94  *      Allocated only when necessary.
  95  */
  96
  97 struct i386_fpsave_state {
  98         boolean_t               fp_valid;
  99         struct i386_fp_save     fp_save_state;
 100         struct i386_fp_regs     fp_regs;
 101         struct i386_fx_save     fx_save_state __attribute__ ((aligned (16)));
 102         int                     fp_save_flavor;
 103 };
 104
 105 /*
 106  *      v86_assist_state:
 107  *
 108  *      This structure provides data to simulate 8086 mode
 109  *      interrupts.  It lives in the pcb.
 110  */
 111
 112 struct v86_assist_state {
 113         vm_offset_t             int_table;
 114         unsigned short          int_count;
 115         unsigned short          flags;  /* 8086 flag bits */
 116 };
 117 #define V86_IF_PENDING          0x8000  /* unused bit */
 118
 119 /*
 120  *      i386_interrupt_state:
 121  *
 122  *      This structure describes the set of registers that must
 123  *      be pushed on the current ring-0 stack by an interrupt before
 124  *      we can switch to the interrupt stack.
 125  */
 126
 127 struct i386_interrupt_state {
 128         int     gs;
 129         int     fs;
 130         int     es;
 131         int     ds;
 132         int     edx;
 133         int     ecx;
 134         int     eax;
 135         int     eip;
 136         int     cs;
 137         int     efl;
 138 };
 139
 140 /*
 141  *      i386_kernel_state:
 142  *
 143  *      This structure corresponds to the state of kernel registers
 144  *      as saved in a context-switch.  It lives at the base of the stack.
 145  */
 146
 147 struct i386_kernel_state {
 148         int                     k_ebx;  /* kernel context */
 149         int                     k_esp;
 150         int                     k_ebp;
 151         int                     k_edi;
 152         int                     k_esi;
 153         int                     k_eip;
 154 };
 155
 156 /*
 157  *      i386_machine_state:
 158  *
 159  *      This structure corresponds to special machine state.
 160  *      It lives in the pcb.  It is not saved by default.
 161  */
 162
 163 struct i386_machine_state {
 164         iopb_tss_t              io_tss;
 165         struct user_ldt *       ldt;
 166         struct i386_fpsave_state *ifps;
 167         struct v86_assist_state v86s;
 168 };
 169
 170 typedef struct pcb {
 171         struct i386_interrupt_state iis[2];     /* interrupt and NMI */
 172         struct i386_saved_state iss;
 173         struct i386_machine_state ims;
 174 #ifdef  MACH_BSD
 175         unsigned long   cthread_self;           /* for use of cthread package */
 176         struct real_descriptor cthread_desc;
 177         unsigned long  uldt_selector;          /* user ldt selector to set */
 178         struct real_descriptor uldt_desc;      /* the actual user setable ldt data */
 179 #endif
 180         decl_simple_lock_data(,lock)
 181 } *pcb_t;
 182
 183 /*
 184  * Maps state flavor to number of words in the state:
 185  */
 186 __private_extern__ unsigned int _MachineStateCount[];
 187
 188 #define USER_REGS(ThrAct)       (&(ThrAct)->machine.pcb->iss)
 189
 190 #define act_machine_state_ptr(ThrAct)   (thread_state_t)USER_REGS(ThrAct)
 191
 192
 193 #define is_user_thread(ThrAct)  \
 194         ((USER_REGS(ThrAct)->efl & EFL_VM) \
 195          || ((USER_REGS(ThrAct)->cs & 0x03) != 0))
 196
 197 #define user_pc(ThrAct)         (USER_REGS(ThrAct)->eip)
 198 #define user_sp(ThrAct)         (USER_REGS(ThrAct)->uesp)
 199
 200 struct machine_thread {
 201         /*
 202          * pointer to process control block
 203          *      (actual storage may as well be here, too)
 204          */
 205         struct pcb xxx_pcb;
 206         pcb_t pcb;
 207
 208 };
 209
 210 extern struct i386_saved_state *get_user_regs(thread_t);
 211
 212 extern void *act_thread_csave(void);
 213 extern void act_thread_catt(void *ctx);
 214 extern void act_thread_cfree(void *ctx);
 215
 216 /*
 217  *      i386_exception_link:
 218  *
 219  *      This structure lives at the high end of the kernel stack.
 220  *      It points to the current thread`s user registers.
 221  */
 222 struct i386_exception_link {
 223         struct i386_saved_state *saved_state;
 224 };
 225
 226
 227 /*
 228  *      On the kernel stack is:
 229  *      stack:  ...
 230  *              struct i386_exception_link
 231  *              struct i386_kernel_state
 232  *      stack+KERNEL_STACK_SIZE
 233  */
 234
 235 #define STACK_IKS(stack)        \
 236         ((struct i386_kernel_state *)((stack) + KERNEL_STACK_SIZE) - 1)
 237 #define STACK_IEL(stack)        \
 238         ((struct i386_exception_link *)STACK_IKS(stack) - 1)
 239
 240 /*
 241  * Return address of the function that called current function, given
 242  *      address of the first parameter of current function.
 243  */
 244 #define GET_RETURN_PC(addr)     (*((vm_offset_t *)addr - 1))
 245
 246 /*
 247  * Defining this indicates that MD code will supply an exception()
 248  * routine, conformant with kern/exception.c (dependency alert!)
 249  * but which does wonderfully fast, machine-dependent magic.
 250  */
 251 #define MACHINE_FAST_EXCEPTION 1
 252
 253 #endif  /* _I386_THREAD_H_ */