LXR linux/arch/x86/include/asm/vm86.h

   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 */
  93