[RFC PATCH 20/32] x86/fred: add a machine check entry stub for FRED

[Xin Li <xin3.li@xxxxxxxxx>]

Add a machine check entry stub for FRED.

Unlike IDT, no need to save/restore dr7 in FRED machine check handler.

Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---
 arch/x86/include/asm/fred.h    |  1 +
 arch/x86/kernel/cpu/mce/core.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h
index 66c274a12e26..01678ced5451 100644
--- a/arch/x86/include/asm/fred.h
+++ b/arch/x86/include/asm/fred.h
@@ -95,6 +95,7 @@ typedef DECLARE_FRED_HANDLER((*fred_handler));
 DECLARE_FRED_HANDLER(fred_exc_nmi);
 DECLARE_FRED_HANDLER(fred_exc_debug);
 DECLARE_FRED_HANDLER(fred_exc_page_fault);
+DECLARE_FRED_HANDLER(fred_exc_machine_check);
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 2c8ec5c71712..0186c9b39f5f 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -52,6 +52,7 @@
 #include <asm/mce.h>
 #include <asm/msr.h>
 #include <asm/reboot.h>
+#include <asm/fred.h>
 
 #include "internal.h"
 
@@ -2121,6 +2122,16 @@ DEFINE_IDTENTRY_MCE_USER(exc_machine_check)
 	exc_machine_check_user(regs);
 	local_db_restore(dr7);
 }
+
+#ifdef CONFIG_X86_FRED
+DEFINE_FRED_HANDLER(fred_exc_machine_check)
+{
+	if (user_mode(regs))
+		exc_machine_check_user(regs);
+	else
+		exc_machine_check_kernel(regs);
+}
+#endif
 #else
 /* 32bit unified entry point */
 DEFINE_IDTENTRY_RAW(exc_machine_check)
-- 
2.34.1