arch/x86/boot/io.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef BOOT_IO_H
   3 #define BOOT_IO_H
   4
   5 #include <asm/shared/io.h>
   6
   7 #undef inb
   8 #undef inw
   9 #undef inl
  10 #undef outb
  11 #undef outw
  12 #undef outl
  13
  14 struct port_io_ops {
  15         u8      (*f_inb)(u16 port);
  16         void    (*f_outb)(u8 v, u16 port);
  17         void    (*f_outw)(u16 v, u16 port);
  18 };
  19
  20 extern struct port_io_ops pio_ops;
  21
  22 /*
  23  * Use the normal I/O instructions by default.
  24  * TDX guests override these to use hypercalls.
  25  */
  26 static inline void init_default_io_ops(void)
  27 {
  28         pio_ops.f_inb  = __inb;
  29         pio_ops.f_outb = __outb;
  30         pio_ops.f_outw = __outw;
  31 }
  32
  33 /*
  34  * Redirect port I/O operations via pio_ops callbacks.
  35  * TDX guests override these callbacks with TDX-specific helpers.
  36  */
  37 #define inb  pio_ops.f_inb
  38 #define outb pio_ops.f_outb
  39 #define outw pio_ops.f_outw
  40
  41 #endif