1 files changed, 101 insertions, 0 deletions
diff --git a/arch/x86_64/lib/copy_page.S b/arch/x86_64/lib/copy_page.S
new file mode 100644
index 0000000..dd3aa47
--- /dev/null
+++ b/arch/x86_64/lib/copy_page.S
@@ -0,0 +1,101 @@
+/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
+	
+/* Don't use streaming store because it's better when the target
+   ends up in cache. */
+	    
+/* Could vary the prefetch distance based on SMP/UP */
+
+	.globl copy_page
+	.p2align 4
+copy_page:
+	subq	$3*8,%rsp
+	movq	%rbx,(%rsp)
+	movq	%r12,1*8(%rsp)
+	movq	%r13,2*8(%rsp)
+			
+	movl	$(4096/64)-5,%ecx
+	.p2align 4
+.Loop64:	
+  	dec     %rcx
+
+	movq        (%rsi), %rax
+	movq      8 (%rsi), %rbx
+	movq     16 (%rsi), %rdx
+	movq     24 (%rsi), %r8
+	movq     32 (%rsi), %r9
+	movq     40 (%rsi), %r10
+	movq     48 (%rsi), %r11
+	movq     56 (%rsi), %r12
+
+	prefetcht0 5*64(%rsi)
+
+	movq     %rax,    (%rdi)
+	movq     %rbx,  8 (%rdi)
+	movq     %rdx, 16 (%rdi)
+	movq     %r8,  24 (%rdi)
+	movq     %r9,  32 (%rdi)
+	movq     %r10, 40 (%rdi)
+	movq     %r11, 48 (%rdi)
+	movq     %r12, 56 (%rdi)
+
+	leaq    64 (%rsi), %rsi
+	leaq    64 (%rdi), %rdi
+
+	jnz     .Loop64
+
+	movl	$5,%ecx
+	.p2align 4
+.Loop2:	
+	decl   %ecx
+
+	movq        (%rsi), %rax
+	movq      8 (%rsi), %rbx
+	movq     16 (%rsi), %rdx
+	movq     24 (%rsi), %r8
+	movq     32 (%rsi), %r9
+	movq     40 (%rsi), %r10
+	movq     48 (%rsi), %r11
+	movq     56 (%rsi), %r12
+
+	movq     %rax,    (%rdi)
+	movq     %rbx,  8 (%rdi)
+	movq     %rdx, 16 (%rdi)
+	movq     %r8,  24 (%rdi)
+	movq     %r9,  32 (%rdi)
+	movq     %r10, 40 (%rdi)
+	movq     %r11, 48 (%rdi)
+	movq     %r12, 56 (%rdi)
+	
+	leaq	64(%rdi),%rdi			
+	leaq	64(%rsi),%rsi			
+	
+	jnz	.Loop2		
+	
+	movq	(%rsp),%rbx
+	movq	1*8(%rsp),%r12
+	movq	2*8(%rsp),%r13
+	addq	$3*8,%rsp
+	ret
+	
+	/* C stepping K8 run faster using the string copy instructions.
+	   It is also a lot simpler. Use this when possible */
+
+#include <asm/cpufeature.h>		
+		
+	.section .altinstructions,"a"
+	.align 8
+	.quad  copy_page
+	.quad  copy_page_c
+	.byte  X86_FEATURE_K8_C
+	.byte  copy_page_c_end-copy_page_c
+	.byte  copy_page_c_end-copy_page_c
+	.previous
+
+	.section .altinstr_replacement,"ax"
+copy_page_c:
+	movl $4096/8,%ecx
+	rep 
+	movsq 
+	ret
+copy_page_c_end:
+	.previous