1#ifndef _ASM_X86_VM86_H 2#define _ASM_X86_VM86_H 3 4/* 5 * I'm guessing at the VIF/VIP flag usage, but hope that this is how 6 * the Pentium uses them. Linux will return from vm86 mode when both 7 * VIF and VIP is set. 8 * 9 * On a Pentium, we could probably optimize the virtual flags directly 10 * in the eflags register instead of doing it "by hand" in vflags... 11 * 12 * Linus 13 */ 14 15#include <asm/processor-flags.h> 16 17#define BIOSSEG 0x0f000 18 19#define CPU_086 0 20#define CPU_186 1 21#define CPU_286 2 22#define CPU_386 3 23#define CPU_486 4 24#define CPU_586 5 25 26/* 27 * Return values for the 'vm86()' system call 28 */ 29#define VM86_TYPE(retval) ((retval) & 0xff) 30#define VM86_ARG(retval) ((retval) >> 8) 31 32#define VM86_SIGNAL 0 /* return due to signal */ 33#define VM86_UNKNOWN 1 /* unhandled GP fault 34 - IO-instruction or similar */ 35#define VM86_INTx 2 /* int3/int x instruction (ARG = x) */ 36#define VM86_STI 3 /* sti/popf/iret instruction enabled 37 virtual interrupts */ 38 39/* 40 * Additional return values when invoking new vm86() 41 */ 42#define VM86_PICRETURN 4 /* return due to pending PIC request */ 43#define VM86_TRAP 6 /* return due to DOS-debugger request */ 44 45/* 46 * function codes when invoking new vm86() 47 */ 48#define VM86_PLUS_INSTALL_CHECK 0 49#define VM86_ENTER 1 50#define VM86_ENTER_NO_BYPASS 2 51#define VM86_REQUEST_IRQ 3 52#define VM86_FREE_IRQ 4 53#define VM86_GET_IRQ_BITS 5 54#define VM86_GET_AND_RESET_IRQ 6 55 56/* 57 * This is the stack-layout seen by the user space program when we have 58 * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout 59 * is 'kernel_vm86_regs' (see below). 60 */ 61 62struct vm86_regs { 63/* 64 * normal regs, with special meaning for the segment descriptors.. 65 */ 66 long ebx; 67 long ecx; 68 long edx; 69 long esi; 70 long edi; 71 long ebp; 72 long eax; 73 long __null_ds; 74 long __null_es; 75 long __null_fs; 76 long __null_gs; 77 long orig_eax; 78 long eip; 79 unsigned short cs, __csh; 80 long eflags; 81 long esp; 82 unsigned short ss, __ssh; 83/* 84 * these are specific to v86 mode: 85 */ 86 unsigned short es, __esh; 87 unsigned short ds, __dsh; 88 unsigned short fs, __fsh; 89 unsigned short gs, __gsh; 90}; 91 92struct revectored_struct { 93 unsigned long __map[8]; /* 256 bits */ 94}; 95 96struct vm86_struct { 97 struct vm86_regs regs; 98 unsigned long flags; 99 unsigned long screen_bitmap; 100 unsigned long cpu_type; 101 struct revectored_struct int_revectored; 102 struct revectored_struct int21_revectored; 103}; 104 105/* 106 * flags masks 107 */ 108#define VM86_SCREEN_BITMAP 0x0001 109 110struct vm86plus_info_struct { 111 unsigned long force_return_for_pic:1; 112 unsigned long vm86dbg_active:1; /* for debugger */ 113 unsigned long vm86dbg_TFpendig:1; /* for debugger */ 114 unsigned long unused:28; 115 unsigned long is_vm86pus:1; /* for vm86 internal use */ 116 unsigned char vm86dbg_intxxtab[32]; /* for debugger */ 117}; 118struct vm86plus_struct { 119 struct vm86_regs regs; 120 unsigned long flags; 121 unsigned long screen_bitmap; 122 unsigned long cpu_type; 123 struct revectored_struct int_revectored; 124 struct revectored_struct int21_revectored; 125 struct vm86plus_info_struct vm86plus; 126}; 127 128#ifdef __KERNEL__ 129 130#include <asm/ptrace.h> 131 132/* 133 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86 134 * mode - the main change is that the old segment descriptors aren't 135 * useful any more and are forced to be zero by the kernel (and the 136 * hardware when a trap occurs), and the real segment descriptors are 137 * at the end of the structure. Look at ptrace.h to see the "normal" 138 * setup. For user space layout see 'struct vm86_regs' above. 139 */ 140 141struct kernel_vm86_regs { 142/* 143 * normal regs, with special meaning for the segment descriptors.. 144 */ 145 struct pt_regs pt; 146/* 147 * these are specific to v86 mode: 148 */ 149 unsigned short es, __esh; 150 unsigned short ds, __dsh; 151 unsigned short fs, __fsh; 152 unsigned short gs, __gsh; 153}; 154 155struct kernel_vm86_struct { 156 struct kernel_vm86_regs regs; 157/* 158 * the below part remains on the kernel stack while we are in VM86 mode. 159 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we 160 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above 161 * 'struct kernel_vm86_regs' with the then actual values. 162 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct' 163 * in kernelspace, hence we need not reget the data from userspace. 164 */ 165#define VM86_TSS_ESP0 flags 166 unsigned long flags; 167 unsigned long screen_bitmap; 168 unsigned long cpu_type; 169 struct revectored_struct int_revectored; 170 struct revectored_struct int21_revectored; 171 struct vm86plus_info_struct vm86plus; 172 struct pt_regs *regs32; /* here we save the pointer to the old regs */ 173/* 174 * The below is not part of the structure, but the stack layout continues 175 * this way. In front of 'return-eip' may be some data, depending on 176 * compilation, so we don't rely on this and save the pointer to 'oldregs' 177 * in 'regs32' above. 178 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this: 179 180 long return-eip; from call to vm86() 181 struct pt_regs oldregs; user space registers as saved by syscall 182 */ 183}; 184 185#ifdef CONFIG_VM86 186 187void handle_vm86_fault(struct kernel_vm86_regs *, long); 188int handle_vm86_trap(struct kernel_vm86_regs *, long, int); 189struct pt_regs *save_v86_state(struct kernel_vm86_regs *); 190 191struct task_struct; 192void release_vm86_irqs(struct task_struct *); 193 194#else 195 196#define handle_vm86_fault(a, b) 197#define release_vm86_irqs(a) 198 199static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c) 200{ 201 return 0; 202} 203 204#endif /* CONFIG_VM86 */ 205 206#endif /* __KERNEL__ */ 207 208#endif /* _ASM_X86_VM86_H */ 209