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authorAl Viro <viro@zeniv.linux.org.uk>2008-08-18 05:05:42 +0400
committerH. Peter Anvin <hpa@zytor.com>2008-10-23 09:55:20 +0400
commitbb8985586b7a906e116db835c64773b7a7d51663 (patch)
treede93ae58e88cc563d95cc124a73f3930594c6100 /arch/x86/include/asm/vm86.h
parent8ede0bdb63305d3353efd97e9af6210afb05734e (diff)
downloadlinux-bb8985586b7a906e116db835c64773b7a7d51663.tar.xz
x86, um: ... and asm-x86 move
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/vm86.h')
-rw-r--r--arch/x86/include/asm/vm86.h208
1 files changed, 208 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vm86.h b/arch/x86/include/asm/vm86.h
new file mode 100644
index 000000000000..998bd18eb737
--- /dev/null
+++ b/arch/x86/include/asm/vm86.h
@@ -0,0 +1,208 @@
+#ifndef ASM_X86__VM86_H
+#define ASM_X86__VM86_H
+
+/*
+ * I'm guessing at the VIF/VIP flag usage, but hope that this is how
+ * the Pentium uses them. Linux will return from vm86 mode when both
+ * VIF and VIP is set.
+ *
+ * On a Pentium, we could probably optimize the virtual flags directly
+ * in the eflags register instead of doing it "by hand" in vflags...
+ *
+ * Linus
+ */
+
+#include <asm/processor-flags.h>
+
+#define BIOSSEG 0x0f000
+
+#define CPU_086 0
+#define CPU_186 1
+#define CPU_286 2
+#define CPU_386 3
+#define CPU_486 4
+#define CPU_586 5
+
+/*
+ * Return values for the 'vm86()' system call
+ */
+#define VM86_TYPE(retval) ((retval) & 0xff)
+#define VM86_ARG(retval) ((retval) >> 8)
+
+#define VM86_SIGNAL 0 /* return due to signal */
+#define VM86_UNKNOWN 1 /* unhandled GP fault
+ - IO-instruction or similar */
+#define VM86_INTx 2 /* int3/int x instruction (ARG = x) */
+#define VM86_STI 3 /* sti/popf/iret instruction enabled
+ virtual interrupts */
+
+/*
+ * Additional return values when invoking new vm86()
+ */
+#define VM86_PICRETURN 4 /* return due to pending PIC request */
+#define VM86_TRAP 6 /* return due to DOS-debugger request */
+
+/*
+ * function codes when invoking new vm86()
+ */
+#define VM86_PLUS_INSTALL_CHECK 0
+#define VM86_ENTER 1
+#define VM86_ENTER_NO_BYPASS 2
+#define VM86_REQUEST_IRQ 3
+#define VM86_FREE_IRQ 4
+#define VM86_GET_IRQ_BITS 5
+#define VM86_GET_AND_RESET_IRQ 6
+
+/*
+ * This is the stack-layout seen by the user space program when we have
+ * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout
+ * is 'kernel_vm86_regs' (see below).
+ */
+
+struct vm86_regs {
+/*
+ * normal regs, with special meaning for the segment descriptors..
+ */
+ long ebx;
+ long ecx;
+ long edx;
+ long esi;
+ long edi;
+ long ebp;
+ long eax;
+ long __null_ds;
+ long __null_es;
+ long __null_fs;
+ long __null_gs;
+ long orig_eax;
+ long eip;
+ unsigned short cs, __csh;
+ long eflags;
+ long esp;
+ unsigned short ss, __ssh;
+/*
+ * these are specific to v86 mode:
+ */
+ unsigned short es, __esh;
+ unsigned short ds, __dsh;
+ unsigned short fs, __fsh;
+ unsigned short gs, __gsh;
+};
+
+struct revectored_struct {
+ unsigned long __map[8]; /* 256 bits */
+};
+
+struct vm86_struct {
+ struct vm86_regs regs;
+ unsigned long flags;
+ unsigned long screen_bitmap;
+ unsigned long cpu_type;
+ struct revectored_struct int_revectored;
+ struct revectored_struct int21_revectored;
+};
+
+/*
+ * flags masks
+ */
+#define VM86_SCREEN_BITMAP 0x0001
+
+struct vm86plus_info_struct {
+ unsigned long force_return_for_pic:1;
+ unsigned long vm86dbg_active:1; /* for debugger */
+ unsigned long vm86dbg_TFpendig:1; /* for debugger */
+ unsigned long unused:28;
+ unsigned long is_vm86pus:1; /* for vm86 internal use */
+ unsigned char vm86dbg_intxxtab[32]; /* for debugger */
+};
+struct vm86plus_struct {
+ struct vm86_regs regs;
+ 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;
+};
+
+#ifdef __KERNEL__
+
+#include <asm/ptrace.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 /* __KERNEL__ */
+
+#endif /* ASM_X86__VM86_H */