x86/alt: Break out alternative-asm into a separate header file

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: 9d7b4351d3
master date: 2018-01-05 19:57:07 +0000

xen/include/asm-x86/alternative-asm.h

@@ -0,0 +1,31 @@
+#ifndef _ASM_X86_ALTERNATIVE_ASM_H_
+#define _ASM_X86_ALTERNATIVE_ASM_H_
+
+#ifdef __ASSEMBLY__
+
+/*
+ * Issue one struct alt_instr descriptor entry (need to put it into
+ * the section .altinstructions, see below). This entry contains
+ * enough information for the alternatives patching code to patch an
+ * instruction. See apply_alternatives().
+ */
+.macro altinstruction_entry orig alt feature orig_len alt_len
+    .long \orig - .
+    .long \alt - .
+    .word \feature
+    .byte \orig_len
+    .byte \alt_len
+.endm
+
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_X86_ALTERNATIVE_ASM_H_ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

xen/include/asm-x86/alternative.h

@@ -1,17 +1,10 @@
 #ifndef __X86_ALTERNATIVE_H__
 #define __X86_ALTERNATIVE_H__
 
+#include <asm/alternative-asm.h>
 #include <asm/nops.h>
 
-#ifdef __ASSEMBLY__
-.macro altinstruction_entry orig alt feature orig_len alt_len
-        .long \orig - .
-        .long \alt - .
-        .word \feature
-        .byte \orig_len
-        .byte \alt_len
-.endm
-#else
+#ifndef __ASSEMBLY__
 #include <xen/stringify.h>
 #include <xen/types.h>
 
@@ -145,6 +138,6 @@ extern void alternative_instructions(void);
 /* Use this macro(s) if you need more than one output parameter. */
 #define ASM_OUTPUT2(a...) a
 
-#endif  /*  __ASSEMBLY__  */
+#endif /*  !__ASSEMBLY__  */
 
 #endif /* __X86_ALTERNATIVE_H__ */