[PATCH v2 5/9] x86/desc: add native_[ig]dt_invalidate() to <asm/desc.h>

[H. Peter Anvin]

From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx>

In some places, we want the native forms of descriptor table
invalidation. Rather than open-coding them, add explicitly native
functions to invalidate the GDT and IDT.

Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
---
 arch/x86/include/asm/desc.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index b8429ae50b71..aa366b2bbc41 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -224,6 +224,21 @@ static inline void store_idt(struct desc_ptr *dtr)
 	asm volatile("sidt %0":"=m" (*dtr));
 }
 
+static const struct desc_ptr __invalid_gdt_idt_ptr __maybe_unused = {
+	.address = 0,
+	.size = 0
+};
+
+static inline void native_gdt_invalidate(void)
+{
+	native_load_gdt(&__invalid_gdt_idt_ptr);
+}
+
+static inline void native_idt_invalidate(void)
+{
+	native_load_idt(&__invalid_gdt_idt_ptr);
+}
+
 /*
  * The LTR instruction marks the TSS GDT entry as busy. On 64-bit, the GDT is
  * a read-only remapping. To prevent a page fault, the GDT is switched to the
-- 
2.31.1