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-rw-r--r--arch/x86/lib/copy_page_64.S89
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/x86/lib/copy_page_64.S b/arch/x86/lib/copy_page_64.S
new file mode 100644
index 000000000..30ea644bf
--- /dev/null
+++ b/arch/x86/lib/copy_page_64.S
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
+
+#include <linux/linkage.h>
+#include <asm/cpufeatures.h>
+#include <asm/alternative.h>
+#include <asm/export.h>
+
+/*
+ * Some CPUs run faster using the string copy instructions (sane microcode).
+ * It is also a lot simpler. Use this when possible. But, don't use streaming
+ * copy unless the CPU indicates X86_FEATURE_REP_GOOD. Could vary the
+ * prefetch distance based on SMP/UP.
+ */
+ ALIGN
+SYM_FUNC_START(copy_page)
+ ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
+ movl $4096/8, %ecx
+ rep movsq
+ RET
+SYM_FUNC_END(copy_page)
+EXPORT_SYMBOL(copy_page)
+
+SYM_FUNC_START_LOCAL(copy_page_regs)
+ subq $2*8, %rsp
+ movq %rbx, (%rsp)
+ movq %r12, 1*8(%rsp)
+
+ movl $(4096/64)-5, %ecx
+ .p2align 4
+.Loop64:
+ dec %rcx
+ movq 0x8*0(%rsi), %rax
+ movq 0x8*1(%rsi), %rbx
+ movq 0x8*2(%rsi), %rdx
+ movq 0x8*3(%rsi), %r8
+ movq 0x8*4(%rsi), %r9
+ movq 0x8*5(%rsi), %r10
+ movq 0x8*6(%rsi), %r11
+ movq 0x8*7(%rsi), %r12
+
+ prefetcht0 5*64(%rsi)
+
+ movq %rax, 0x8*0(%rdi)
+ movq %rbx, 0x8*1(%rdi)
+ movq %rdx, 0x8*2(%rdi)
+ movq %r8, 0x8*3(%rdi)
+ movq %r9, 0x8*4(%rdi)
+ movq %r10, 0x8*5(%rdi)
+ movq %r11, 0x8*6(%rdi)
+ movq %r12, 0x8*7(%rdi)
+
+ leaq 64 (%rsi), %rsi
+ leaq 64 (%rdi), %rdi
+
+ jnz .Loop64
+
+ movl $5, %ecx
+ .p2align 4
+.Loop2:
+ decl %ecx
+
+ movq 0x8*0(%rsi), %rax
+ movq 0x8*1(%rsi), %rbx
+ movq 0x8*2(%rsi), %rdx
+ movq 0x8*3(%rsi), %r8
+ movq 0x8*4(%rsi), %r9
+ movq 0x8*5(%rsi), %r10
+ movq 0x8*6(%rsi), %r11
+ movq 0x8*7(%rsi), %r12
+
+ movq %rax, 0x8*0(%rdi)
+ movq %rbx, 0x8*1(%rdi)
+ movq %rdx, 0x8*2(%rdi)
+ movq %r8, 0x8*3(%rdi)
+ movq %r9, 0x8*4(%rdi)
+ movq %r10, 0x8*5(%rdi)
+ movq %r11, 0x8*6(%rdi)
+ movq %r12, 0x8*7(%rdi)
+
+ leaq 64(%rdi), %rdi
+ leaq 64(%rsi), %rsi
+ jnz .Loop2
+
+ movq (%rsp), %rbx
+ movq 1*8(%rsp), %r12
+ addq $2*8, %rsp
+ RET
+SYM_FUNC_END(copy_page_regs)