1 files changed, 131 insertions, 0 deletions
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
new file mode 100644
index 0000000..c22981f
--- /dev/null
+++ b/arch/x86/lib/memcpy_64.S
@@ -0,0 +1,131 @@
+/* Copyright 2002 Andi Kleen */
+
+#include <linux/linkage.h>
+#include <asm/dwarf2.h>
+#include <asm/cpufeature.h>
+
+/*
+ * memcpy - Copy a memory block.
+ *
+ * Input:	
+ * rdi destination
+ * rsi source
+ * rdx count
+ * 
+ * Output:
+ * rax original destination
+ */	
+
+	ALIGN
+memcpy_c:
+	CFI_STARTPROC
+	movq %rdi,%rax
+	movl %edx,%ecx
+	shrl $3,%ecx
+	andl $7,%edx
+	rep movsq
+	movl %edx,%ecx
+	rep movsb
+	ret
+	CFI_ENDPROC
+ENDPROC(memcpy_c)
+
+ENTRY(__memcpy)
+ENTRY(memcpy)
+	CFI_STARTPROC
+	pushq %rbx
+	CFI_ADJUST_CFA_OFFSET 8
+	CFI_REL_OFFSET rbx, 0
+	movq %rdi,%rax
+
+	movl %edx,%ecx
+	shrl $6,%ecx
+	jz .Lhandle_tail
+
+	.p2align 4
+.Lloop_64:
+	decl %ecx
+
+	movq (%rsi),%r11
+	movq 8(%rsi),%r8
+
+	movq %r11,(%rdi)
+	movq %r8,1*8(%rdi)
+
+	movq 2*8(%rsi),%r9
+	movq 3*8(%rsi),%r10
+
+	movq %r9,2*8(%rdi)
+	movq %r10,3*8(%rdi)
+
+	movq 4*8(%rsi),%r11
+	movq 5*8(%rsi),%r8
+
+	movq %r11,4*8(%rdi)
+	movq %r8,5*8(%rdi)
+
+	movq 6*8(%rsi),%r9
+	movq 7*8(%rsi),%r10
+
+	movq %r9,6*8(%rdi)
+	movq %r10,7*8(%rdi)
+
+	leaq 64(%rsi),%rsi
+	leaq 64(%rdi),%rdi
+	jnz  .Lloop_64
+
+.Lhandle_tail:
+	movl %edx,%ecx
+	andl $63,%ecx
+	shrl $3,%ecx
+	jz   .Lhandle_7
+	.p2align 4
+.Lloop_8:
+	decl %ecx
+	movq (%rsi),%r8
+	movq %r8,(%rdi)
+	leaq 8(%rdi),%rdi
+	leaq 8(%rsi),%rsi
+	jnz  .Lloop_8
+
+.Lhandle_7:
+	movl %edx,%ecx
+	andl $7,%ecx
+	jz .Lende
+	.p2align 4
+.Lloop_1:
+	movb (%rsi),%r8b
+	movb %r8b,(%rdi)
+	incq %rdi
+	incq %rsi
+	decl %ecx
+	jnz .Lloop_1
+
+.Lende:
+	popq %rbx
+	CFI_ADJUST_CFA_OFFSET -8
+	CFI_RESTORE rbx
+	ret
+.Lfinal:
+	CFI_ENDPROC
+ENDPROC(memcpy)
+ENDPROC(__memcpy)
+
+	/* Some CPUs run faster using the string copy instructions.
+	   It is also a lot simpler. Use this when possible */
+
+	.section .altinstr_replacement,"ax"
+1:	.byte 0xeb				/* jmp <disp8> */
+	.byte (memcpy_c - memcpy) - (2f - 1b)	/* offset */
+2:
+	.previous
+	.section .altinstructions,"a"
+	.align 8
+	.quad memcpy
+	.quad 1b
+	.byte X86_FEATURE_REP_GOOD
+	/* Replace only beginning, memcpy is used to apply alternatives, so it
+	 * is silly to overwrite itself with nops - reboot is only outcome... */
+	.byte 2b - 1b
+	.byte 2b - 1b
+	.previous