--- zzzz-none-000/linux-3.10.107/arch/x86/lib/clear_page_64.S	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/x86/lib/clear_page_64.S	2021-02-04 17:41:59.000000000 +0000
@@ -1,31 +1,31 @@
 #include <linux/linkage.h>
-#include <asm/dwarf2.h>
+#include <asm/cpufeature.h>
 #include <asm/alternative-asm.h>
 
 /*
- * Zero a page. 	
- * rdi	page
- */			
-ENTRY(clear_page_c)
-	CFI_STARTPROC
+ * Most CPUs support enhanced REP MOVSB/STOSB instructions. It is
+ * recommended to use this when possible and we do use them by default.
+ * If enhanced REP MOVSB/STOSB is not available, try to use fast string.
+ * Otherwise, use original.
+ */
+
+/*
+ * Zero a page.
+ * %rdi	- page
+ */
+ENTRY(clear_page)
+
+	ALTERNATIVE_2 "jmp clear_page_orig", "", X86_FEATURE_REP_GOOD, \
+		      "jmp clear_page_c_e", X86_FEATURE_ERMS
+
 	movl $4096/8,%ecx
 	xorl %eax,%eax
 	rep stosq
 	ret
-	CFI_ENDPROC
-ENDPROC(clear_page_c)
+ENDPROC(clear_page)
 
-ENTRY(clear_page_c_e)
-	CFI_STARTPROC
-	movl $4096,%ecx
-	xorl %eax,%eax
-	rep stosb
-	ret
-	CFI_ENDPROC
-ENDPROC(clear_page_c_e)
+ENTRY(clear_page_orig)
 
-ENTRY(clear_page)
-	CFI_STARTPROC
 	xorl   %eax,%eax
 	movl   $4096/64,%ecx
 	.p2align 4
@@ -44,30 +44,11 @@
 	jnz	.Lloop
 	nop
 	ret
-	CFI_ENDPROC
-.Lclear_page_end:
-ENDPROC(clear_page)
-
-	/*
-	 * Some CPUs support enhanced REP MOVSB/STOSB instructions.
-	 * It is recommended to use this when possible.
-	 * If enhanced REP MOVSB/STOSB is not available, try to use fast string.
-	 * Otherwise, use original function.
-	 *
-	 */
-
-#include <asm/cpufeature.h>
+ENDPROC(clear_page_orig)
 
-	.section .altinstr_replacement,"ax"
-1:	.byte 0xeb					/* jmp <disp8> */
-	.byte (clear_page_c - clear_page) - (2f - 1b)	/* offset */
-2:	.byte 0xeb					/* jmp <disp8> */
-	.byte (clear_page_c_e - clear_page) - (3f - 2b)	/* offset */
-3:
-	.previous
-	.section .altinstructions,"a"
-	altinstruction_entry clear_page,1b,X86_FEATURE_REP_GOOD,\
-			     .Lclear_page_end-clear_page, 2b-1b
-	altinstruction_entry clear_page,2b,X86_FEATURE_ERMS,   \
-			     .Lclear_page_end-clear_page,3b-2b
-	.previous
+ENTRY(clear_page_c_e)
+	movl $4096,%ecx
+	xorl %eax,%eax
+	rep stosb
+	ret
+ENDPROC(clear_page_c_e)