[PATCH V2 32/41] x86/nmi: Use C entry code

[Lai Jiangshan]

From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

Use DEFINE_IDTENTRY_IST_ETNRY to emit C entry function and use the function
directly in entry_64.S.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
 arch/x86/entry/entry_64.S       | 17 ++---------------
 arch/x86/include/asm/idtentry.h |  5 ++++-
 2 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 0ba788bb9857..72a1610bb540 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1271,21 +1271,8 @@ end_repeat_nmi:
 	PUSH_AND_CLEAR_REGS
 	ENCODE_FRAME_POINTER
 
-	/*
-	 * Use paranoid_entry to handle SWAPGS and CR3.
-	 */
-	call	paranoid_entry
-	UNWIND_HINT_REGS
-
-	movq	%rsp, %rdi
-	movq	$-1, %rsi
-	call	exc_nmi
-
-	/*
-	 * Use paranoid_exit to handle SWAPGS and CR3, but no need to use
-	 * restore_regs_and_return_to_kernel as we must handle nested NMI.
-	 */
-	call	paranoid_exit
+	movq	%rsp, %rdi		/* pt_regs pointer */
+	call	ist_exc_nmi
 
 	POP_REGS
 
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 49c0ebe374ae..c99c58bc179a 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -358,6 +358,8 @@ __visible __entry_text void ist_##func(struct pt_regs *regs)		\
 #define DEFINE_IDTENTRY_NOIST(func)					\
 	DEFINE_IDTENTRY_RAW(noist_##func)
 
+#define DEFINE_IDTENTRY_NMI		DEFINE_IDTENTRY_IST
+
 #define DECLARE_IDTENTRY_MCE		DECLARE_IDTENTRY_IST
 #define DEFINE_IDTENTRY_MCE		DEFINE_IDTENTRY_IST
 #define DEFINE_IDTENTRY_MCE_USER	DEFINE_IDTENTRY_NOIST
@@ -407,6 +409,8 @@ __visible __entry_text void ist_##func(struct pt_regs *regs)		\
 
 #else	/* CONFIG_X86_64 */
 
+#define DEFINE_IDTENTRY_NMI		DEFINE_IDTENTRY_RAW
+
 /**
  * DECLARE_IDTENTRY_DF - Declare functions for double fault 32bit variant
  * @vector:	Vector number (ignored for C)
@@ -438,7 +442,6 @@ __visible noinstr void func(struct pt_regs *regs,			\
 
 /* C-Code mapping */
 #define DECLARE_IDTENTRY_NMI		DECLARE_IDTENTRY_RAW
-#define DEFINE_IDTENTRY_NMI		DEFINE_IDTENTRY_RAW
 
 #else /* !__ASSEMBLY__ */
 
-- 
2.19.1.6.gb485710b