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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 :
62 : struct 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 :
92 : struct revectored_struct {
93 : unsigned long __map[8]; /* 256 bits */
94 : };
95 :
96 : struct 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 :
110 : struct 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 : };
118 : struct 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 :
141 : struct 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 :
155 : struct 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 :
187 : void handle_vm86_fault(struct kernel_vm86_regs *, long);
188 : int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
189 : struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
190 :
191 : struct task_struct;
192 : void release_vm86_irqs(struct task_struct *);
193 :
194 : #else
195 :
196 : #define handle_vm86_fault(a, b)
197 : #define release_vm86_irqs(a)
198 :
199 : static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
200 : {
201 : return 0;
202 : }
203 2 :
204 : #endif /* CONFIG_VM86 */
205 :
206 : #endif /* __KERNEL__ */
207 :
208 : #endif /* _ASM_X86_VM86_H */
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