xref: /openbmc/linux/arch/m68k/lib/memcpy.c (revision 827634ad)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file COPYING in the main directory of this archive
4  * for more details.
5  */
6 
7 #include <linux/module.h>
8 #include <linux/string.h>
9 
10 void *memcpy(void *to, const void *from, size_t n)
11 {
12 	void *xto = to;
13 	size_t temp;
14 
15 	if (!n)
16 		return xto;
17 	if ((long)to & 1) {
18 		char *cto = to;
19 		const char *cfrom = from;
20 		*cto++ = *cfrom++;
21 		to = cto;
22 		from = cfrom;
23 		n--;
24 	}
25 #if defined(CONFIG_M68000)
26 	if ((long)from & 1) {
27 		char *cto = to;
28 		const char *cfrom = from;
29 		for (; n; n--)
30 			*cto++ = *cfrom++;
31 		return xto;
32 	}
33 #endif
34 	if (n > 2 && (long)to & 2) {
35 		short *sto = to;
36 		const short *sfrom = from;
37 		*sto++ = *sfrom++;
38 		to = sto;
39 		from = sfrom;
40 		n -= 2;
41 	}
42 	temp = n >> 2;
43 	if (temp) {
44 		long *lto = to;
45 		const long *lfrom = from;
46 #if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
47 		for (; temp; temp--)
48 			*lto++ = *lfrom++;
49 #else
50 		size_t temp1;
51 		asm volatile (
52 			"	movel %2,%3\n"
53 			"	andw  #7,%3\n"
54 			"	lsrl  #3,%2\n"
55 			"	negw  %3\n"
56 			"	jmp   %%pc@(1f,%3:w:2)\n"
57 			"4:	movel %0@+,%1@+\n"
58 			"	movel %0@+,%1@+\n"
59 			"	movel %0@+,%1@+\n"
60 			"	movel %0@+,%1@+\n"
61 			"	movel %0@+,%1@+\n"
62 			"	movel %0@+,%1@+\n"
63 			"	movel %0@+,%1@+\n"
64 			"	movel %0@+,%1@+\n"
65 			"1:	dbra  %2,4b\n"
66 			"	clrw  %2\n"
67 			"	subql #1,%2\n"
68 			"	jpl   4b"
69 			: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
70 			: "0" (lfrom), "1" (lto), "2" (temp));
71 #endif
72 		to = lto;
73 		from = lfrom;
74 	}
75 	if (n & 2) {
76 		short *sto = to;
77 		const short *sfrom = from;
78 		*sto++ = *sfrom++;
79 		to = sto;
80 		from = sfrom;
81 	}
82 	if (n & 1) {
83 		char *cto = to;
84 		const char *cfrom = from;
85 		*cto = *cfrom;
86 	}
87 	return xto;
88 }
89 EXPORT_SYMBOL(memcpy);
90