1 files changed, 82 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vm86.h b/arch/x86/include/asm/vm86.h
new file mode 100644
index 000000000..1d8de3f3f
--- /dev/null
+++ b/arch/x86/include/asm/vm86.h
@@ -0,0 +1,82 @@
+#ifndef _ASM_X86_VM86_H
+#define _ASM_X86_VM86_H
+
+
+#include <asm/ptrace.h>
+#include <uapi/asm/vm86.h>
+
+/*
+ * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
+ * mode - the main change is that the old segment descriptors aren't
+ * useful any more and are forced to be zero by the kernel (and the
+ * hardware when a trap occurs), and the real segment descriptors are
+ * at the end of the structure. Look at ptrace.h to see the "normal"
+ * setup. For user space layout see 'struct vm86_regs' above.
+ */
+
+struct kernel_vm86_regs {
+/*
+ * normal regs, with special meaning for the segment descriptors..
+ */
+	struct pt_regs pt;
+/*
+ * these are specific to v86 mode:
+ */
+	unsigned short es, __esh;
+	unsigned short ds, __dsh;
+	unsigned short fs, __fsh;
+	unsigned short gs, __gsh;
+};
+
+struct kernel_vm86_struct {
+	struct kernel_vm86_regs regs;
+/*
+ * the below part remains on the kernel stack while we are in VM86 mode.
+ * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we
+ * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above
+ * 'struct kernel_vm86_regs' with the then actual values.
+ * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct'
+ * in kernelspace, hence we need not reget the data from userspace.
+ */
+#define VM86_TSS_ESP0 flags
+	unsigned long flags;
+	unsigned long screen_bitmap;
+	unsigned long cpu_type;
+	struct revectored_struct int_revectored;
+	struct revectored_struct int21_revectored;
+	struct vm86plus_info_struct vm86plus;
+	struct pt_regs *regs32;   /* here we save the pointer to the old regs */
+/*
+ * The below is not part of the structure, but the stack layout continues
+ * this way. In front of 'return-eip' may be some data, depending on
+ * compilation, so we don't rely on this and save the pointer to 'oldregs'
+ * in 'regs32' above.
+ * However, with GCC-2.7.2 and the current CFLAGS you see exactly this:
+
+	long return-eip;        from call to vm86()
+	struct pt_regs oldregs;  user space registers as saved by syscall
+ */
+};
+
+#ifdef CONFIG_VM86
+
+void handle_vm86_fault(struct kernel_vm86_regs *, long);
+int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
+struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
+
+struct task_struct;
+void release_vm86_irqs(struct task_struct *);
+
+#else
+
+#define handle_vm86_fault(a, b)
+#define release_vm86_irqs(a)
+
+static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
+{
+	return 0;
+}
+
+#endif /* CONFIG_VM86 */
+
+#endif /* _ASM_X86_VM86_H */