1 #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
15 #define TF_MASK 0x00000100
16 #define IF_MASK 0x00000200
17 #define IOPL_MASK 0x00003000
18 #define NT_MASK 0x00004000
19 #ifdef CONFIG_VM86
20 #define VM_MASK 0x00020000
21 #else
22 #define VM_MASK 0 /* ignored */
23 #endif
24 #define AC_MASK 0x00040000
25 #define VIF_MASK 0x00080000 /* virtual interrupt flag */
26 #define VIP_MASK 0x00100000 /* virtual interrupt pending */
27 #define ID_MASK 0x00200000
28
29 #define BIOSSEG 0x0f000
30
31 #define CPU_086 0
32 #define CPU_186 1
33 #define CPU_286 2
34 #define CPU_386 3
35 #define CPU_486 4
36 #define CPU_586 5
37
38 /*
39 * Return values for the 'vm86()' system call
40 */
41 #define VM86_TYPE(retval) ((retval) & 0xff)
42 #define VM86_ARG(retval) ((retval) >> 8)
43
44 #define VM86_SIGNAL 0 /* return due to signal */
45 #define VM86_UNKNOWN 1 /* unhandled GP fault - IO-instruction or similar */
46 #define VM86_INTx 2 /* int3/int x instruction (ARG = x) */
47 #define VM86_STI 3 /* sti/popf/iret instruction enabled virtual interrupts */
48
49 /*
50 * Additional return values when invoking new vm86()
51 */
52 #define VM86_PICRETURN 4 /* return due to pending PIC request */
53 #define VM86_TRAP 6 /* return due to DOS-debugger request */
54
55 /*
56 * function codes when invoking new vm86()
57 */
58 #define VM86_PLUS_INSTALL_CHECK 0
59 #define VM86_ENTER 1
60 #define VM86_ENTER_NO_BYPASS 2
61 #define VM86_REQUEST_IRQ 3
62 #define VM86_FREE_IRQ 4
63 #define VM86_GET_IRQ_BITS 5
64 #define VM86_GET_AND_RESET_IRQ 6
65
66 /*
67 * This is the stack-layout seen by the user space program when we have
68 * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout
69 * is 'kernel_vm86_regs' (see below).
70 */
71
72 struct vm86_regs {
73 /*
74 * normal regs, with special meaning for the segment descriptors..
75 */
76 long ebx;
77 long ecx;
78 long edx;
79 long esi;
80 long edi;
81 long ebp;
82 long eax;
83 long __null_ds;
84 long __null_es;
85 long __null_fs;
86 long __null_gs;
87 long orig_eax;
88 long eip;
89 unsigned short cs, __csh;
90 long eflags;
91 long esp;
92 unsigned short ss, __ssh;
93 /*
94 * these are specific to v86 mode:
95 */
96 unsigned short es, __esh;
97 unsigned short ds, __dsh;
98 unsigned short fs, __fsh;
99 unsigned short gs, __gsh;
100 };
101
102 struct revectored_struct {
103 unsigned long __map[8]; /* 256 bits */
104 };
105
106 struct vm86_struct {
107 struct vm86_regs regs;
108 unsigned long flags;
109 unsigned long screen_bitmap;
110 unsigned long cpu_type;
111 struct revectored_struct int_revectored;
112 struct revectored_struct int21_revectored;
113 };
114
115 /*
116 * flags masks
117 */
118 #define VM86_SCREEN_BITMAP 0x0001
119
120 struct vm86plus_info_struct {
121 unsigned long force_return_for_pic:1;
122 unsigned long vm86dbg_active:1; /* for debugger */
123 unsigned long vm86dbg_TFpendig:1; /* for debugger */
124 unsigned long unused:28;
125 unsigned long is_vm86pus:1; /* for vm86 internal use */
126 unsigned char vm86dbg_intxxtab[32]; /* for debugger */
127 };
128
129 struct vm86plus_struct {
130 struct vm86_regs regs;
131 unsigned long flags;
132 unsigned long screen_bitmap;
133 unsigned long cpu_type;
134 struct revectored_struct int_revectored;
135 struct revectored_struct int21_revectored;
136 struct vm86plus_info_struct vm86plus;
137 };
138
139 #ifdef __KERNEL__
140 /*
141 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
142 * mode - the main change is that the old segment descriptors aren't
143 * useful any more and are forced to be zero by the kernel (and the
144 * hardware when a trap occurs), and the real segment descriptors are
145 * at the end of the structure. Look at ptrace.h to see the "normal"
146 * setup. For user space layout see 'struct vm86_regs' above.
147 */
148 #include <asm/ptrace.h>
149
150 struct kernel_vm86_regs {
151 /*
152 * normal regs, with special meaning for the segment descriptors..
153 */
154 struct pt_regs pt;
155 /*
156 * these are specific to v86 mode:
157 */
158 unsigned short es, __esh;
159 unsigned short ds, __dsh;
160 unsigned short fs, __fsh;
161 unsigned short gs, __gsh;
162 };
163
164 struct kernel_vm86_struct {
165 struct kernel_vm86_regs regs;
166 /*
167 * the below part remains on the kernel stack while we are in VM86 mode.
168 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we
169 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above
170 * 'struct kernel_vm86_regs' with the then actual values.
171 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct'
172 * in kernelspace, hence we need not reget the data from userspace.
173 */
174 #define VM86_TSS_ESP0 flags
175 unsigned long flags;
176 unsigned long screen_bitmap;
177 unsigned long cpu_type;
178 struct revectored_struct int_revectored;
179 struct revectored_struct int21_revectored;
180 struct vm86plus_info_struct vm86plus;
181 struct pt_regs *regs32; /* here we save the pointer to the old regs */
182 /*
183 * The below is not part of the structure, but the stack layout continues
184 * this way. In front of 'return-eip' may be some data, depending on
185 * compilation, so we don't rely on this and save the pointer to 'oldregs'
186 * in 'regs32' above.
187 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this:
188
189 long return-eip; from call to vm86()
190 struct pt_regs oldregs; user space registers as saved by syscall
191 */
192 };
193
194 #ifdef CONFIG_VM86
195
196 void handle_vm86_fault(struct kernel_vm86_regs *, long);
197 int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
198
199 struct task_struct;
200 void release_vm86_irqs(struct task_struct *);
201
202 #else
203
204 #define handle_vm86_fault(a, b)
205 #define release_vm86_irqs(a)
206
handle_vm86_trap(struct kernel_vm86_regs * a,long b,int c)207 static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c) {
208 return 0;
209 }
210
211 #endif /* CONFIG_VM86 */
212
213 #endif /* __KERNEL__ */
214
215 #endif
216