1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_VM86_H
3#define _ASM_X86_VM86_H
4
5#include <asm/ptrace.h>
6#include <uapi/asm/vm86.h>
7
8/*
9 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
10 * mode - the main change is that the old segment descriptors aren't
11 * useful any more and are forced to be zero by the kernel (and the
12 * hardware when a trap occurs), and the real segment descriptors are
13 * at the end of the structure. Look at ptrace.h to see the "normal"
14 * setup. For user space layout see 'struct vm86_regs' above.
15 */
16
17struct kernel_vm86_regs {
18/*
19 * normal regs, with special meaning for the segment descriptors..
20 */
21 struct pt_regs pt;
22/*
23 * these are specific to v86 mode:
24 */
25 unsigned short es, __esh;
26 unsigned short ds, __dsh;
27 unsigned short fs, __fsh;
28 unsigned short gs, __gsh;
29};
30
31struct vm86 {
32 struct vm86plus_struct __user *user_vm86;
33 struct pt_regs regs32;
34 unsigned long veflags;
35 unsigned long veflags_mask;
36 unsigned long saved_sp0;
37
38 unsigned long flags;
39 unsigned long cpu_type;
40 struct revectored_struct int_revectored;
41 struct revectored_struct int21_revectored;
42 struct vm86plus_info_struct vm86plus;
43};
44
45#ifdef CONFIG_VM86
46
47void handle_vm86_fault(struct kernel_vm86_regs *, long);
48int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
49void save_v86_state(struct kernel_vm86_regs *, int);
50
51struct task_struct;
52
53#define free_vm86(t) do { \
54 struct thread_struct *__t = (t); \
55 if (__t->vm86 != NULL) { \
56 kfree(__t->vm86); \
57 __t->vm86 = NULL; \
58 } \
59} while (0)
60
61/*
62 * Support for VM86 programs to request interrupts for
63 * real mode hardware drivers:
64 */
65#define FIRST_VM86_IRQ 3
66#define LAST_VM86_IRQ 15
67
68static inline int invalid_vm86_irq(int irq)
69{
70 return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
71}
72
73void release_vm86_irqs(struct task_struct *);
74
75#else
76
77#define handle_vm86_fault(a, b)
78#define release_vm86_irqs(a)
79
80static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
81{
82 return 0;
83}
84
85static inline void save_v86_state(struct kernel_vm86_regs *a, int b) { }
86
87#define free_vm86(task) do { (void)(task); } while(0)
88
89#endif /* CONFIG_VM86 */
90
91#endif /* _ASM_X86_VM86_H */
92