[tip: x86/irq] x86: Add native_[ig]dt_invalidate()

[tip-bot2 for H. Peter Anvin (Intel)]

The following commit has been merged into the x86/irq branch of tip:

Commit-ID:     283fa3b6483a84aeb62f1b97c2ec7c02eb2f5882
Gitweb:        https://git.kernel.org/tip/283fa3b6483a84aeb62f1b97c2ec7c02eb2f5882
Author:        H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
AuthorDate:    Wed, 19 May 2021 14:21:51 -07:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 21 May 2021 12:36:45 +02:00

x86: Add native_[ig]dt_invalidate()

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

Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210519212154.511983-6-hpa@xxxxxxxxx

---
 arch/x86/include/asm/desc.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index b8429ae..400c178 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -224,6 +224,26 @@ static inline void store_idt(struct desc_ptr *dtr)
 	asm volatile("sidt %0":"=m" (*dtr));
 }
 
+static inline void native_gdt_invalidate(void)
+{
+	const struct desc_ptr invalid_gdt = {
+		.address = 0,
+		.size = 0
+	};
+
+	native_load_gdt(&invalid_gdt);
+}
+
+static inline void native_idt_invalidate(void)
+{
+	const struct desc_ptr invalid_idt = {
+		.address = 0,
+		.size = 0
+	};
+
+	native_load_idt(&invalid_idt);
+}
+
 /*
  * 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