x86_64: move lib

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 59 insertions, 0 deletions

diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S
new file mode 100644
index 000000000000..9a10a78bb4a4
--- /dev/null
+++ b/arch/x86/lib/clear_page_64.S
@@ -0,0 +1,59 @@
+#include <linux/linkage.h>
+#include <asm/dwarf2.h>
+
+/*
+ * Zero a page.         
+ * rdi  page
+ */                     
+        ALIGN
+clear_page_c:
+        CFI_STARTPROC
+        movl $4096/8,%ecx
+        xorl %eax,%eax
+        rep stosq
+        ret
+        CFI_ENDPROC
+ENDPROC(clear_page)
+
+ENTRY(clear_page)
+        CFI_STARTPROC
+        xorl   %eax,%eax
+        movl   $4096/64,%ecx
+        .p2align 4
+.Lloop:
+        decl    %ecx
+#define PUT(x) movq %rax,x*8(%rdi)
+        movq %rax,(%rdi)
+        PUT(1)
+        PUT(2)
+        PUT(3)
+        PUT(4)
+        PUT(5)
+        PUT(6)
+        PUT(7)
+        leaq    64(%rdi),%rdi
+        jnz     .Lloop
+        nop
+        ret
+        CFI_ENDPROC
+.Lclear_page_end:
+ENDPROC(clear_page)
+
+        /* Some CPUs run faster using the string instructions.
+           It is also a lot simpler. Use this when possible */
+
+#include <asm/cpufeature.h>
+
+        .section .altinstr_replacement,"ax"
+1:      .byte 0xeb                                      /* jmp <disp8> */
+        .byte (clear_page_c - clear_page) - (2f - 1b)   /* offset */
+2:
+        .previous
+        .section .altinstructions,"a"
+        .align 8
+        .quad clear_page
+        .quad 1b
+        .byte X86_FEATURE_REP_GOOD
+        .byte .Lclear_page_end - clear_page
+        .byte 2b - 1b
+        .previous