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Diffstat (limited to 'arch/x86/lib/copy_page_64.S')
-rw-r--r--arch/x86/lib/copy_page_64.S37
1 files changed, 12 insertions, 25 deletions
diff --git a/arch/x86/lib/copy_page_64.S b/arch/x86/lib/copy_page_64.S
index 176cca67212b..8239dbcbf984 100644
--- a/arch/x86/lib/copy_page_64.S
+++ b/arch/x86/lib/copy_page_64.S
@@ -2,23 +2,26 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
+#include <asm/cpufeature.h>
#include <asm/alternative-asm.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
-copy_page_rep:
+ENTRY(copy_page)
CFI_STARTPROC
+ ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
movl $4096/8, %ecx
rep movsq
ret
CFI_ENDPROC
-ENDPROC(copy_page_rep)
-
-/*
- * Don't use streaming copy unless the CPU indicates X86_FEATURE_REP_GOOD.
- * Could vary the prefetch distance based on SMP/UP.
-*/
+ENDPROC(copy_page)
-ENTRY(copy_page)
+ENTRY(copy_page_regs)
CFI_STARTPROC
subq $2*8, %rsp
CFI_ADJUST_CFA_OFFSET 2*8
@@ -90,21 +93,5 @@ ENTRY(copy_page)
addq $2*8, %rsp
CFI_ADJUST_CFA_OFFSET -2*8
ret
-.Lcopy_page_end:
CFI_ENDPROC
-ENDPROC(copy_page)
-
- /* Some CPUs run faster using the string copy 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 (copy_page_rep - copy_page) - (2f - 1b) /* offset */
-2:
- .previous
- .section .altinstructions,"a"
- altinstruction_entry copy_page, 1b, X86_FEATURE_REP_GOOD, \
- .Lcopy_page_end-copy_page, 2b-1b
- .previous
+ENDPROC(copy_page_regs)