1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
3*4882a593Smuzhiyun * Copyright (C) 2004 Microtronix Datacom Ltd
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * This file is subject to the terms and conditions of the GNU General Public
6*4882a593Smuzhiyun * License. See the file "COPYING" in the main directory of this archive
7*4882a593Smuzhiyun * for more details.
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/types.h>
11*4882a593Smuzhiyun #include <linux/string.h>
12*4882a593Smuzhiyun
memset(void * s,int c,size_t count)13*4882a593Smuzhiyun void *memset(void *s, int c, size_t count)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun int destptr, charcnt, dwordcnt, fill8reg, wrkrega;
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun if (!count)
18*4882a593Smuzhiyun return s;
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun c &= 0xFF;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun if (count <= 8) {
23*4882a593Smuzhiyun char *xs = (char *) s;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun while (count--)
26*4882a593Smuzhiyun *xs++ = c;
27*4882a593Smuzhiyun return s;
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun __asm__ __volatile__ (
31*4882a593Smuzhiyun /* fill8 %3, %5 (c & 0xff) */
32*4882a593Smuzhiyun " slli %4, %5, 8\n"
33*4882a593Smuzhiyun " or %4, %4, %5\n"
34*4882a593Smuzhiyun " slli %3, %4, 16\n"
35*4882a593Smuzhiyun " or %3, %3, %4\n"
36*4882a593Smuzhiyun /* Word-align %0 (s) if necessary */
37*4882a593Smuzhiyun " andi %4, %0, 0x01\n"
38*4882a593Smuzhiyun " beq %4, zero, 1f\n"
39*4882a593Smuzhiyun " addi %1, %1, -1\n"
40*4882a593Smuzhiyun " stb %3, 0(%0)\n"
41*4882a593Smuzhiyun " addi %0, %0, 1\n"
42*4882a593Smuzhiyun "1: mov %2, %1\n"
43*4882a593Smuzhiyun /* Dword-align %0 (s) if necessary */
44*4882a593Smuzhiyun " andi %4, %0, 0x02\n"
45*4882a593Smuzhiyun " beq %4, zero, 2f\n"
46*4882a593Smuzhiyun " addi %1, %1, -2\n"
47*4882a593Smuzhiyun " sth %3, 0(%0)\n"
48*4882a593Smuzhiyun " addi %0, %0, 2\n"
49*4882a593Smuzhiyun " mov %2, %1\n"
50*4882a593Smuzhiyun /* %1 and %2 are how many more bytes to set */
51*4882a593Smuzhiyun "2: srli %2, %2, 2\n"
52*4882a593Smuzhiyun /* %2 is how many dwords to set */
53*4882a593Smuzhiyun "3: stw %3, 0(%0)\n"
54*4882a593Smuzhiyun " addi %0, %0, 4\n"
55*4882a593Smuzhiyun " addi %2, %2, -1\n"
56*4882a593Smuzhiyun " bne %2, zero, 3b\n"
57*4882a593Smuzhiyun /* store residual word and/or byte if necessary */
58*4882a593Smuzhiyun " andi %4, %1, 0x02\n"
59*4882a593Smuzhiyun " beq %4, zero, 4f\n"
60*4882a593Smuzhiyun " sth %3, 0(%0)\n"
61*4882a593Smuzhiyun " addi %0, %0, 2\n"
62*4882a593Smuzhiyun /* store residual byte if necessary */
63*4882a593Smuzhiyun "4: andi %4, %1, 0x01\n"
64*4882a593Smuzhiyun " beq %4, zero, 5f\n"
65*4882a593Smuzhiyun " stb %3, 0(%0)\n"
66*4882a593Smuzhiyun "5:\n"
67*4882a593Smuzhiyun : "=r" (destptr), /* %0 Output */
68*4882a593Smuzhiyun "=r" (charcnt), /* %1 Output */
69*4882a593Smuzhiyun "=r" (dwordcnt), /* %2 Output */
70*4882a593Smuzhiyun "=r" (fill8reg), /* %3 Output */
71*4882a593Smuzhiyun "=&r" (wrkrega) /* %4 Output only */
72*4882a593Smuzhiyun : "r" (c), /* %5 Input */
73*4882a593Smuzhiyun "0" (s), /* %0 Input/Output */
74*4882a593Smuzhiyun "1" (count) /* %1 Input/Output */
75*4882a593Smuzhiyun : "memory" /* clobbered */
76*4882a593Smuzhiyun );
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun return s;
79*4882a593Smuzhiyun }
80