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-rw-r--r--arch/x86/boot/io.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/x86/boot/io.h b/arch/x86/boot/io.h
new file mode 100644
index 000000000..110880907
--- /dev/null
+++ b/arch/x86/boot/io.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_IO_H
+#define BOOT_IO_H
+
+#include <asm/shared/io.h>
+
+#undef inb
+#undef inw
+#undef inl
+#undef outb
+#undef outw
+#undef outl
+
+struct port_io_ops {
+ u8 (*f_inb)(u16 port);
+ void (*f_outb)(u8 v, u16 port);
+ void (*f_outw)(u16 v, u16 port);
+};
+
+extern struct port_io_ops pio_ops;
+
+/*
+ * Use the normal I/O instructions by default.
+ * TDX guests override these to use hypercalls.
+ */
+static inline void init_default_io_ops(void)
+{
+ pio_ops.f_inb = __inb;
+ pio_ops.f_outb = __outb;
+ pio_ops.f_outw = __outw;
+}
+
+/*
+ * Redirect port I/O operations via pio_ops callbacks.
+ * TDX guests override these callbacks with TDX-specific helpers.
+ */
+#define inb pio_ops.f_inb
+#define outb pio_ops.f_outb
+#define outw pio_ops.f_outw
+
+#endif