[PATCH 03/15] x86/alternative: Add alternative_input_2

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

Add alternative_input_2 to take two features and respective instructions.

If CPU has feature2, newinstr2 is used.

Otherwise, if CPU has feature1, newinstr1 is used.

Otherwise, oldinstr is used.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 arch/x86/include/asm/alternative.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 0a3f9c9..eb8d80b 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -161,6 +161,19 @@ static inline int alternatives_text_reserved(void *start, void *end)
 	asm volatile (ALTERNATIVE(oldinstr, newinstr, feature)		\
 		: : "i" (0), ## input)
 
+/*
+ * Like alternative_input, but there are two features and respective
+ * instructions.
+ * If CPU has feature2, newinstr2 is used.
+ * Otherwise, if CPU has feature1, newinstr1 is used.
+ * Otherwise, oldinstr is used.
+ */
+#define alternative_input_2(oldinstr, newinstr1, feature1, newinstr2,	     \
+			   feature2, input...)				     \
+	asm volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1,	     \
+		newinstr2, feature2)					     \
+		: : "i" (0), ## input)
+
 /* Like alternative_input, but with a single output argument */
 #define alternative_io(oldinstr, newinstr, feature, output, input...)	\
 	asm volatile (ALTERNATIVE(oldinstr, newinstr, feature)		\
-- 
1.8.1.2

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