add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/arch/x86/lib/memmove_64.S
..
..
@@ -8,7 +8,7 @@
8
8
  */
9
9
 #include <linux/linkage.h>
10
10
 #include <asm/cpufeatures.h>
11
-#include <asm/alternative-asm.h>
11
+#include <asm/alternative.h>
12
12
 #include <asm/export.h>
13
13
 
14
14
 #undef memmove
..
..
@@ -24,15 +24,10 @@
24
24
  * Output:
25
25
  * rax: dest
26
26
  */
27
-.weak memmove
28
-.p2align 4, 0x90
29
-memmove:
30
-ENTRY(__memmove)
27
+SYM_FUNC_START_WEAK(memmove)
28
+SYM_FUNC_START(__memmove)
31
29
 
32
-	/* Handle more 32 bytes in loop */
33
30
 	mov %rdi, %rax
34
-	cmp $0x20, %rdx
35
-	jb	1f
36
31
 
37
32
 	/* Decide forward/backward copy mode */
38
33
 	cmp %rdi, %rsi
..
..
@@ -42,8 +37,10 @@
42
37
 	cmp %rdi, %r8
43
38
 	jg 2f
44
39
 
40
+	/* FSRM implies ERMS => no length checks, do the copy directly */
45
41
 .Lmemmove_begin_forward:
46
-	ALTERNATIVE "", "movq %rdx, %rcx; rep movsb; retq", X86_FEATURE_ERMS
42
+	ALTERNATIVE "cmp $0x20, %rdx; jb 1f", "", X86_FEATURE_FSRM
43
+	ALTERNATIVE "", "jmp .Lmemmove_erms", X86_FEATURE_ERMS
47
44
 
48
45
 	/*
49
46
 	 * movsq instruction have many startup latency
..
..
@@ -114,6 +111,8 @@
114
111
 	 */
115
112
 	.p2align 4
116
113
 2:
114
+	cmp $0x20, %rdx
115
+	jb 1f
117
116
 	cmp $680, %rdx
118
117
 	jb 6f
119
118
 	cmp %dil, %sil
..
..
@@ -206,8 +205,13 @@
206
205
 	movb (%rsi), %r11b
207
206
 	movb %r11b, (%rdi)
208
207
 13:
209
-	retq
210
-ENDPROC(__memmove)
211
-ENDPROC(memmove)
208
+	RET
209
+
210
+.Lmemmove_erms:
211
+	movq %rdx, %rcx
212
+	rep movsb
213
+	RET
214
+SYM_FUNC_END(__memmove)
215
+SYM_FUNC_END_ALIAS(memmove)
212
216
 EXPORT_SYMBOL(__memmove)
213
217
 EXPORT_SYMBOL(memmove)