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
handle_vm86_trap(struct kernel_vm86_regs * a,long b,int c)199 static 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