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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_VM86_H
2#define _LINUX_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
gorcunov@gmail.coma5c15d42008-03-28 17:56:56 +030015#include <asm/processor-flags.h>
16
Matt Mackall64ca9002006-01-08 01:05:26 -080017#ifdef CONFIG_VM86
gorcunov@gmail.com6b6891f2008-03-28 17:56:57 +030018#define X86_VM_MASK X86_EFLAGS_VM
Matt Mackall64ca9002006-01-08 01:05:26 -080019#else
gorcunov@gmail.com6b6891f2008-03-28 17:56:57 +030020#define X86_VM_MASK 0 /* No VM86 support */
Matt Mackall64ca9002006-01-08 01:05:26 -080021#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#define BIOSSEG 0x0f000
24
25#define CPU_086 0
26#define CPU_186 1
27#define CPU_286 2
28#define CPU_386 3
29#define CPU_486 4
30#define CPU_586 5
31
32/*
33 * Return values for the 'vm86()' system call
34 */
35#define VM86_TYPE(retval) ((retval) & 0xff)
36#define VM86_ARG(retval) ((retval) >> 8)
37
38#define VM86_SIGNAL 0 /* return due to signal */
Joe Perches9e8a9352008-03-23 01:03:58 -070039#define VM86_UNKNOWN 1 /* unhandled GP fault
40 - IO-instruction or similar */
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#define VM86_INTx 2 /* int3/int x instruction (ARG = x) */
Joe Perches9e8a9352008-03-23 01:03:58 -070042#define VM86_STI 3 /* sti/popf/iret instruction enabled
43 virtual interrupts */
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45/*
46 * Additional return values when invoking new vm86()
47 */
48#define VM86_PICRETURN 4 /* return due to pending PIC request */
49#define VM86_TRAP 6 /* return due to DOS-debugger request */
50
51/*
52 * function codes when invoking new vm86()
53 */
54#define VM86_PLUS_INSTALL_CHECK 0
55#define VM86_ENTER 1
56#define VM86_ENTER_NO_BYPASS 2
57#define VM86_REQUEST_IRQ 3
58#define VM86_FREE_IRQ 4
59#define VM86_GET_IRQ_BITS 5
60#define VM86_GET_AND_RESET_IRQ 6
61
62/*
63 * This is the stack-layout seen by the user space program when we have
64 * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout
65 * is 'kernel_vm86_regs' (see below).
66 */
67
68struct vm86_regs {
69/*
70 * normal regs, with special meaning for the segment descriptors..
71 */
72 long ebx;
73 long ecx;
74 long edx;
75 long esi;
76 long edi;
77 long ebp;
78 long eax;
79 long __null_ds;
80 long __null_es;
81 long __null_fs;
82 long __null_gs;
83 long orig_eax;
84 long eip;
85 unsigned short cs, __csh;
86 long eflags;
87 long esp;
88 unsigned short ss, __ssh;
89/*
90 * these are specific to v86 mode:
91 */
92 unsigned short es, __esh;
93 unsigned short ds, __dsh;
94 unsigned short fs, __fsh;
95 unsigned short gs, __gsh;
96};
97
98struct revectored_struct {
99 unsigned long __map[8]; /* 256 bits */
100};
101
102struct vm86_struct {
103 struct vm86_regs regs;
104 unsigned long flags;
105 unsigned long screen_bitmap;
106 unsigned long cpu_type;
107 struct revectored_struct int_revectored;
108 struct revectored_struct int21_revectored;
109};
110
111/*
112 * flags masks
113 */
114#define VM86_SCREEN_BITMAP 0x0001
115
116struct vm86plus_info_struct {
117 unsigned long force_return_for_pic:1;
118 unsigned long vm86dbg_active:1; /* for debugger */
119 unsigned long vm86dbg_TFpendig:1; /* for debugger */
120 unsigned long unused:28;
121 unsigned long is_vm86pus:1; /* for vm86 internal use */
122 unsigned char vm86dbg_intxxtab[32]; /* for debugger */
123};
124
125struct vm86plus_struct {
126 struct vm86_regs regs;
127 unsigned long flags;
128 unsigned long screen_bitmap;
129 unsigned long cpu_type;
130 struct revectored_struct int_revectored;
131 struct revectored_struct int21_revectored;
132 struct vm86plus_info_struct vm86plus;
133};
134
135#ifdef __KERNEL__
136/*
137 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
138 * mode - the main change is that the old segment descriptors aren't
139 * useful any more and are forced to be zero by the kernel (and the
140 * hardware when a trap occurs), and the real segment descriptors are
141 * at the end of the structure. Look at ptrace.h to see the "normal"
142 * setup. For user space layout see 'struct vm86_regs' above.
143 */
Jeremy Fitzhardinge49d26b62006-12-07 02:14:03 +0100144#include <asm/ptrace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146struct kernel_vm86_regs {
147/*
148 * normal regs, with special meaning for the segment descriptors..
149 */
Jeremy Fitzhardinge49d26b62006-12-07 02:14:03 +0100150 struct pt_regs pt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151/*
152 * these are specific to v86 mode:
153 */
154 unsigned short es, __esh;
155 unsigned short ds, __dsh;
156 unsigned short fs, __fsh;
157 unsigned short gs, __gsh;
158};
159
160struct kernel_vm86_struct {
161 struct kernel_vm86_regs regs;
162/*
163 * the below part remains on the kernel stack while we are in VM86 mode.
164 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we
165 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above
166 * 'struct kernel_vm86_regs' with the then actual values.
167 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct'
168 * in kernelspace, hence we need not reget the data from userspace.
169 */
170#define VM86_TSS_ESP0 flags
171 unsigned long flags;
172 unsigned long screen_bitmap;
173 unsigned long cpu_type;
174 struct revectored_struct int_revectored;
175 struct revectored_struct int21_revectored;
176 struct vm86plus_info_struct vm86plus;
177 struct pt_regs *regs32; /* here we save the pointer to the old regs */
178/*
179 * The below is not part of the structure, but the stack layout continues
180 * this way. In front of 'return-eip' may be some data, depending on
181 * compilation, so we don't rely on this and save the pointer to 'oldregs'
182 * in 'regs32' above.
183 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this:
184
185 long return-eip; from call to vm86()
186 struct pt_regs oldregs; user space registers as saved by syscall
187 */
188};
189
Matt Mackall64ca9002006-01-08 01:05:26 -0800190#ifdef CONFIG_VM86
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192void handle_vm86_fault(struct kernel_vm86_regs *, long);
193int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
Harvey Harrisone04f99c2008-02-04 16:48:04 +0100194struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Matt Mackall64ca9002006-01-08 01:05:26 -0800196struct task_struct;
197void release_vm86_irqs(struct task_struct *);
198
199#else
200
201#define handle_vm86_fault(a, b)
202#define release_vm86_irqs(a)
203
Joe Perches9e8a9352008-03-23 01:03:58 -0700204static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
205{
Matt Mackall64ca9002006-01-08 01:05:26 -0800206 return 0;
207}
208
209#endif /* CONFIG_VM86 */
210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211#endif /* __KERNEL__ */
212
213#endif