include/asm/vm86.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_VM86_H
0003 #define _ASM_X86_VM86_H
0004
0005 #include <asm/ptrace.h>
0006 #include <uapi/asm/vm86.h>
0007
0008 /*
0009  * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
0010  * mode - the main change is that the old segment descriptors aren't
0011  * useful any more and are forced to be zero by the kernel (and the
0012  * hardware when a trap occurs), and the real segment descriptors are
0013  * at the end of the structure. Look at ptrace.h to see the "normal"
0014  * setup. For user space layout see 'struct vm86_regs' above.
0015  */
0016
0017 struct kernel_vm86_regs {
0018 /*
0019  * normal regs, with special meaning for the segment descriptors..
0020  */
0021     struct pt_regs pt;
0022 /*
0023  * these are specific to v86 mode:
0024  */
0025     unsigned short es, __esh;
0026     unsigned short ds, __dsh;
0027     unsigned short fs, __fsh;
0028     unsigned short gs, __gsh;
0029 };
0030
0031 struct vm86 {
0032     struct vm86plus_struct __user *user_vm86;
0033     struct pt_regs regs32;
0034     unsigned long veflags;
0035     unsigned long veflags_mask;
0036     unsigned long saved_sp0;
0037
0038     unsigned long flags;
0039     unsigned long cpu_type;
0040     struct revectored_struct int_revectored;
0041     struct revectored_struct int21_revectored;
0042     struct vm86plus_info_struct vm86plus;
0043 };
0044
0045 #ifdef CONFIG_VM86
0046
0047 void handle_vm86_fault(struct kernel_vm86_regs *, long);
0048 int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
0049 void save_v86_state(struct kernel_vm86_regs *, int);
0050
0051 struct task_struct;
0052
0053 #define free_vm86(t) do {               \
0054     struct thread_struct *__t = (t);        \
0055     if (__t->vm86 != NULL) {            \
0056         kfree(__t->vm86);           \
0057         __t->vm86 = NULL;           \
0058     }                       \
0059 } while (0)
0060
0061 /*
0062  * Support for VM86 programs to request interrupts for
0063  * real mode hardware drivers:
0064  */
0065 #define FIRST_VM86_IRQ       3
0066 #define LAST_VM86_IRQ       15
0067
0068 static inline int invalid_vm86_irq(int irq)
0069 {
0070     return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
0071 }
0072
0073 void release_vm86_irqs(struct task_struct *);
0074
0075 #else
0076
0077 #define handle_vm86_fault(a, b)
0078 #define release_vm86_irqs(a)
0079
0080 static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
0081 {
0082     return 0;
0083 }
0084
0085 static inline void save_v86_state(struct kernel_vm86_regs *a, int b) { }
0086
0087 #define free_vm86(t) do { } while(0)
0088
0089 #endif /* CONFIG_VM86 */
0090
0091 #endif /* _ASM_X86_VM86_H */