[PATCH RESEND v9 02/36] x86/fred: Add Kconfig option for FRED (CONFIG_X86_FRED)

[Xin Li]

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

Add the configuration option CONFIG_X86_FRED to enable FRED.

Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---
 arch/x86/Kconfig | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7422db409770..700d94cb8330 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -494,6 +494,15 @@ config X86_CPU_RESCTRL
 
 	  Say N if unsure.
 
+config X86_FRED
+	bool "Flexible Return and Event Delivery"
+	depends on X86_64
+	help
+	  When enabled, try to use Flexible Return and Event Delivery
+	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
+	  ring transitions and exception/interrupt handling if the
+	  system supports.
+
 if X86_32
 config X86_BIGSMP
 	bool "Support for big SMP systems with more than 8 CPUs"
-- 
2.34.1