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 screen_bitmap;
40	unsigned long cpu_type;
41	struct revectored_struct int_revectored;
42	struct revectored_struct int21_revectored;
43	struct vm86plus_info_struct vm86plus;
44};
45
46#ifdef CONFIG_VM86
47
48void handle_vm86_fault(struct kernel_vm86_regs *, long);
49int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
50void save_v86_state(struct kernel_vm86_regs *, int);
51
52struct task_struct;
53
54#define free_vm86(t) do {				\
55	struct thread_struct *__t = (t);		\
56	if (__t->vm86 != NULL) {			\
57		kfree(__t->vm86);			\
58		__t->vm86 = NULL;			\
59	}						\
60} while (0)
61
62/*
63 * Support for VM86 programs to request interrupts for
64 * real mode hardware drivers:
65 */
66#define FIRST_VM86_IRQ		 3
67#define LAST_VM86_IRQ		15
68
69static inline int invalid_vm86_irq(int irq)
70{
71	return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
72}
73
74void release_vm86_irqs(struct task_struct *);
75
76#else
77
78#define handle_vm86_fault(a, b)
79#define release_vm86_irqs(a)
80
81static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
82{
83	return 0;
84}
85
86static inline void save_v86_state(struct kernel_vm86_regs *a, int b) { }
87
88#define free_vm86(t) do { } while(0)
89
90#endif /* CONFIG_VM86 */
91
92#endif /* _ASM_X86_VM86_H */